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In 1938, Professor E. Simmons (Simmons) of the California Institute of Technology and A. Ruge (Prof. MIT), professors of the Massachusetts Institute of Technology, simultaneously developed paper-based wire-wound resistance strain gages with their names prefixed with two The assistant is named SR-4 and is produced by the American BLH company. It has laid a theoretical and material foundation for the development of strain load sensors.
In 1940, American A.Thurston (Thurston), the chief engineer of BLH and Revere company, developed a cylindrical strain gauge load cell using SR-4 strain strain gage. It was used in engineering force measurement and weighing measurement to become a strain load. The founder of the sensor. In 1942, strain load sensors in the United States were mass-produced and have been in existence for more than 60 years.
For the first 30 years or more, it is the world of the load cell with column, cylinder, ring, and beam structure using normal stress (tension, compression, and bending stress). During this period, the British scholar Jackson developed a metal foil resistance strain gauge, which provided an ideal conversion element for the load cell and created a new process for attaching a resistance strain gauge with thermosetting glue. After years of practice, BLH and Revere have created load sensor circuit compensation and adjustment processes to improve the accuracy and stability of the load cell. The accuracy has increased from a few percent in the 1940s to a 0.05 in the early 1970s. Magnitude. However, the problems in the application process are also very prominent, mainly: the increase in force point will cause a relatively large sensitivity changes; simultaneous pull, pressure cycle load sensitivity deviation; anti-offset and lateral load capacity is poor; can not be small Load measurement. The above disadvantages severely restrict the development of load sensors.
After more than 30 years, experienced two major technological breakthroughs in the 70s shear stress load sensor and aluminum alloy small-scale load sensor; in the 1980s, the load cell and load cell were completely separated, formulated R60 international recommendations and developed a digital smart load cell. Two major reforms; in the 90's in the structural design and manufacturing process continue to incorporate high-tech to meet new challenges and accelerate the development of load cell technology.
In 1973, American scholar Hogsttem proposed to overcome the intrinsic shortcomings of normal stress load sensors and proposed to use the shear stress independent of the bending moment to design the load sensor theory without using normal stress, and to design a circular I-section cantilever shear Cut beam type load cell. Breaking the world of normal stress load sensors has formed a new trend of development. This is a major breakthrough in the design of load cell structures.
Around 1974, American scholar Stein and German scholar Edom proposed the establishment of a more complex mechanical model of elastic body. Using finite element calculation method, the strength, stiffness, stress field and displacement field of the elastic body were analyzed to obtain the optimal design. . A new approach has been opened up for the design and calculation of load sensors using modern analysis methods and calculation methods.
In the mid-1970s, weighing instrument manufacturing companies in the United States, Japan, and other countries began to develop commercial electronic pricing scales, which are in urgent need of small-range load sensors. Traditional normal stress and newly developed shear load sensors cannot achieve measurements in the range of several kilograms to several tens of kilograms. Schatz, an American scholar, proposed using aluminum alloys with low elastic modulus as elastic bodies and using multi-beam structures to solve the contradiction between sensitivity and stiffness. A small-range aluminum alloy parallel beam load cell was designed. It was also pointed out that the parallel beam load cell was based on the principle of constant bending moment, which makes use of the normal stress structure of the parallel beam surface bending stress, and has the characteristics of shear stress load sensor, which is a parallel beam structure. The design and calculation of load sensors laid a theoretical foundation and formed another development trend.
Creep is a key issue that resistance strain gauges and aluminum alloy load sensors often encounter and must address. Before 1978, the Soviet scholar Kolokokova analyzed the one-dimensional mechanical model and the strain transfer coefficient, and proposed the ratio of the gate width and grid width of the resistance strain gage sensitive grid to make different creep resistance strain gages. The theory, and successfully developed a series of creep compensation strain gauges. It plays a crucial role in reducing creep error and improving accuracy for low-capacity aluminum alloy load sensors, making it possible to use aluminum alloy load sensors with multiple varieties and mass production for electronic pricing scales.
Due to the rapid development of electronic weighing technology, the evaluation method of load sensor performance can no longer meet the needs of using ladder tolerance zone to assess the accuracy of electronic weighing scales, and urgently needs measurement procedures that are compatible with the accuracy evaluation methods of electronic weighing instruments. In the early 1980s, the Office of International Legal Metrology (OIML) Quality Measurement Guidance Secretariat decided to completely separate the sensors for electronic weighing from the sensors used for force measurement. The 8th report secretariat drafted by the United States drafted “Weighing sensor measurement. Procedures. After a written vote by OIML member states, it was formally approved at the 7th Legal Metrology Conference in October 1984, and was issued in 1985 with the OIML, R60 international recommendations and was issued to all member states. At present, the countries are implementing the 2000 version of the R60. It can be said that R60 "weighing sensor measurement procedures" is a "passport" for weighing sensors in various countries to enter the international market.
With the development of digital technology and information technology, the demand for digital electronic scales in various industries is increasing. It is proposed that digital weighing systems break through the limitations of analog weighing systems, and analog load sensors cannot do anything about this. Because before this, the research of the weighing sensor is all concentrated on the hardware aspect, for example: Innovate the structure of the elastomer, improve the manufacturing craft, improve the circuit to compensate and adjust and so on. The output signal of the analog load cell is small, the anti-jamming capability is poor, the transmission distance is short, the weighing display control instrument is complex, and the shortcomings such as the long debugging period of the group scale remain the same. In order to meet the demand of digital electronic scales, the United States TOLEDO, STS and CARDINAL companies, Germany HBM companies have developed integrated and separate digital intelligent load cells, and with its large output signal, anti-interference ability, signal transmission distance Far, easy to implement intelligent control and other characteristics, become digital electronic weighing and automatic weighing measurement and control system must be selected products, forming a hot spot for development.
In the 1990s, due to the maturation of basic technologies such as the design and calculation of load cells, the development of load cells was focused on process research and applied research. There were product standardization, serialization, engineering design, and large-scale production processes. Great progress, mainly:
Introduce computer simulation technology and virtual technology in structure and process design;
Incorporation of flexible manufacturing technology in elastomer processing;
Use computer network technology in the production process;
Transplantation of vibration aging and new resonance aging process in stable treatment;
Automatic quick detection and dynamic comparison methods were created in test verification.
Breakthrough progress has also been made in the application of technology: on the basis of traditional weighing modules, new weighing modules have been developed. This is a typical product that uses new technologies to face new challenges. Its characteristic is componentized design, with "plug and play" function, can reduce the weight error due to weight, thermal effects, accidental overload, etc., and can withstand the bias caused by vibration, impact, agitation or other external forces. In short, two technological breakthroughs in the 1970s, two major changes in the 1980s, and the concept of research and development that incorporated new high technologies in the 1990s to face new challenges have greatly promoted the development of load cell technology.
Second, the status quo of foreign load cell technology and rapid development reasons Industrial and commercial electronic weighing scales with load cell technology and manufacturing processes, the United States, Germany and other famous industrial companies in developed countries in the leading position in the international market leader, China has a certain scale The weighing sensor manufacturing company is in the market challenger or market follower status. The R&D and production center for load cells for household electronic scales is in China. In Shenzhen, the manufacturing technology, technological level, product quality and annual output have increased year by year.
The competition in today's international market for load cell technology focuses on competition in product accuracy, stability, and reliability; competition between manufacturing technology and manufacturing processes; and application of high-tech research and development for new products and competition for proprietary intellectual property products. Each weighing sensor manufacturing company is striving to cultivate its own core competitive technology and build core competitive products.
From the products exhibited at the International Weighing Instruments Industry Exhibition in recent years and the analysis of the products of a number of market leaders, it can be concluded that the common pursuit of these companies is that the elastomer materials are more sophisticated; the resistance strain gauges and compensation elements The device's technical requirements and environmental stress screening are more stringent; the manufacturing process is more refined; the circuit compensation process is more complete; and the appearance quality is more perfect.
The accuracy, stability, and reliability of the load cell are important quality indicators. At the same time, they are also of the most concern to the user. In response, these companies have conducted many research and experimental work in structural design, manufacturing processes, circuit compensation and adjustment, and stability handling, and have made significant progress. The main achievements are:
(1) In the process of structural design and calculation, computer simulation technology was introduced to carry out dynamic simulation and dynamic analysis. Computer simulation technology was introduced into the process design process to simulate and test the elastomer production process.
(2) In the processing of elastomers, advanced manufacturing technologies are incorporated, and rigid manufacturing is changed to flexible manufacturing. Universal use of machining centers, flexible manufacturing units, and flexible manufacturing systems;
(3) In the whole production process, manual operation and artificial control are minimized, semi-automatic and automatic control and automatic inspection procedures are added, and computer network technology is used in the production process;
(4) Improve and innovate process equipment to achieve highly efficient intelligent circuit compensation, establish a fully automatic rapid inspection system, and improve the success rate of C3 grade products and the sampling qualification rate of mass production products;
(5) Transplant advanced stable processing technologies and equipment, implement new processes of vibration aging or resonance aging, and improve the long-term stability and reliability of the load cell;
(6) Apply new and high technology to develop new products and independent intellectual property rights products to enhance core competitiveness. Companies in the leading position in the international market have their own core competitive technologies, processes and products, such as: "O creep" load cells for positive and negative creep bridges; bronze dynamic load cells; integral and discrete digital Smart load cell; high-accuracy stainless steel 3-column, 4-column high-temperature load cell; modularized plug-and-play new-type weighing module.
The development characteristics of foreign load cell technology and the reasons for rapid development:
(1) Pay attention to the research of basic technologies, basic technologies and common key technologies. Do basic research and pre-research in parallel. Common key technology research and applied technology research in parallel. Typical product development and product engineering in parallel. Ensure that the basic technology and basic processes (resistance strain gauges, strain adhesives, compensation components, protective and sealing materials, etc.) have been in the world's leading position.
(2) Emphasize the research and application of infrastructure construction and manufacturing technologies and manufacturing processes. Good configuration of technical equipment and testing equipment, especially intelligent process equipment, made the most advanced technology and equipment;
(3) To describe the development trend and strategic frontier of the world weighing sensor technology, and to determine the research topics and product development direction. Emphasis on the development of new products and proprietary intellectual property products and enhance core competitiveness. The standards of its technological innovation and new product development are: high technical lead, advanced technology, market proliferation, and efficiency proliferation. Make technology and process always lead the world.
(4) Emphasize the reliability design, control and management of the load cell, strictly design the conformity control and process reliability control, and strive to achieve 100% of the process redemption rate.
(5) Pay attention to market competition, strengthen market investigation and analysis, and quickly respond to the market. In the 21st century, market competition is focused on market response speed and based on improved and innovative products.
(6) Pay attention to the study of relevant laws and regulations, fully understand and implement them carefully, and ensure that every product produced meets the requirements.
Because of this, a wide variety of foreign load cells, complete specifications, alloy steel, aluminum alloy, stainless steel, bronze bronze products are everything; underwater, under the drilling measurement, pressure explosion-proof, anti-radiation, anti-corrosion products; small and ultra-large-scale ; Weighing and dynamic weighing; integrated and modular structure for any user to buy. In addition, both the internal and external quality of the product are emphasized. In recent years, the appearance quality has been improved and improved. There are basically no paint products, and almost all of them are bright or matte chemical nickel plating, chrome plating, paint, plastic spray, and porcelain anodization. Stainless steel products. The shape of individual products has been integrated into humanized design.
The current research and development hotspots are:
Digital compensation technology and compensation technology of digital smart load cell, and its application technology;
Rapid, low-speed dynamic and dynamic load cell development and damping technology;
High temperature load cell manufacturing process, high temperature stability and application technology;
Pressure and explosion proof load cell and pressure shell design and test technology;
"Plug & Play" new weigh modules for modular design;
Using helium and neon instead of nickel to make sensitive temperature compensation resistors.
Third, the status of China's load cell technology and the main gap Although China's aviation and aerospace industry as early as the late 1950s began to study the application of strain-type load sensors, but did not develop for civilian use. As far as the whole country is concerned, the development and production of load sensors started late. In the 1960s, only a few manufacturers produced strain gauge load cells with ordinary precision grades. The structure is single, only two structures, cylindrical, circular, basically do not carry out circuit compensation and adjustment, some products even use the external balance box to adjust the zero point.
In the early 1980s, more than 20 companies throughout the country spent 100 million yuan to use Swindon's 13 million U.S. dollars to import strain gauge load sensor manufacturing technology and equipment from the United States and Japan to learn, digest, and absorb. After imitation and trial production, many varieties of small batch production began, and after the market was launched, considerable benefits were achieved. At that time, people concluded that this product is: more varieties, small quantities, low cost, high yield, less investment, and quick results. The attention of individuals and enterprises in many industries has entered this industry. Manufacturers have rapidly increased from more than 20 in the 1970s to more than 100, and the annual output is equivalent to that in Japan, reaching more than 1 million.
With the development of the national economy, the demand for electronic scales in various industries has continuously increased, which has greatly promoted the development of load cell technology. From the mid-1980s to the mid-1990s, it was a decade in which the technology of weighing sensors in China has developed steadily, and the varieties and specifications have rapidly increased and the quality of products has been continuously improved. Many manufacturers have improved or added process equipment and instrumentation, purchased intelligent temperature compensation devices and sensitivity temperature compensation equipment, and achieved large-scale production. In the mid-1990s, the number of weighing sensor manufacturers increased to more than 160, with an annual output of more than 2 million. In addition to meeting the needs of the domestic market, more than a dozen companies began exporting in small quantities, showing a good momentum of development.
Although weighing sensors are legally-measured measuring instruments that are subject to mandatory management by the state, they should be more difficult to enter the industry. However, due to various reasons, it is easy for some enterprises and individuals to enter, causing market congestion and exacerbating market competition. Finally the price war broke out in the mid-1990s. The price was low, and whoever was the big winner, and the year-by-year escalation became even more fierce. The evil consequences of price wars are slow technological progress, declining technological levels, serious quality problems, and uncontrolled management supervision. The initial victims were the vast majority of users. The ultimate victim was the company itself and was the entire weighing sensor industry. With these issues entering the 21st century, the gap between the weighing sensors and the industrialized countries has not narrowed, but has increased. The results of the national supervision and spot checks in recent years are examples.
In 2002, the state supervised and spot-checked 7 provinces and cities, 16 enterprises, a total of 48 weighing sensors, and qualified 18, with a pass rate of 37.5%. Thirty unqualified products came from 10 companies. The reason for the failure was all the poor temperature performance. What is more serious is that of the 16 companies, only one company strictly implements the national standards. If you change to a full inspection, the pass rate will be lower. The results of national supervision and spot checks have truly reflected the overall technology, process and management level of China's load cells. The main reasons for the low pass rate are: poor quality awareness, not organized production according to law; no understanding or implementation of R60 international recommendations and national standards, equating 0.02 and C3 levels erroneously; changing materials and replacing components under profit drive , reduce the process, only for barely qualified or artificially qualified.
The main gap between China's load cells and industrial advanced countries in the market leading position of enterprise products is:
(1) There are few types of structures, incomplete specifications, and scarcity of special-purpose products;
(2) The accuracy level is low, and the success rate of C3 level is not high;
(3) Poor stability and reliability, high repair rate, and low working life;
(4) The level of product standardization, engineering, and the degree of industrialization of enterprises are low, and the uniformity of product technical indicators is poor;
(5) Although the appearance quality has improved, there is still a large gap;
(6) Technology equipment and testing methods are not advanced enough and are not matched. The manual operation and artificial control components in the production process are large. The “workshop art†has deep traces, and human factors have a greater impact on product quality;
(7) There are few innovative products and independent intellectual property products, and there are many low-level repeated products, and there are few OEM products and direct export products;
(8) The company does not have core competitive technologies and products. The market survey is not enough, and the market response is too slow, resulting in the inability to integrate with the international market.
In short, the manufacturing process has the largest gap, and the manufacturing process is usually divided into:
Supporting processes for elastomer forging, machining, heat treatment and surface treatment;
Basic processes - resistance strain gauges, strain adhesives, circuit compensation components, and protective sealing materials;
Core process - resistance strain gauge paste and curing, zero point and sensitivity, intelligent temperature compensation and protection and sealing;
Special process one by one heat treatment aging process and mechanical stabilization process.
The gap between the basic process and the special process is the largest.
Household electronic scales (body scales, health scales, fat scales, kitchen scales, nutrition scales, treasure scales, pocket scales, hand-held scales, etc.) Weighing sensors and their resistance strain gauges. Since the mid-1990s, research and development and production have come from the world. Countries gradually moved to China, mainly in Guangdong and Shenzhen. In recent years, shocking developments in design technology, manufacturing processes and product output have been made. There are three types of production companies: one is the design, production, and assembly of various household electronic scales; the other is the production of various load cells (or self-produced strain gages or outsourced strain gages) for home electronic scales. Three of them produce resistance strain gages for household electronic scale load cells. At present, these three types of manufacturers have reached more than 60. According to the statistics of the country's customs, in 2003, the export volume of household electronic scales was over 38.6 million units, and the export value was 147 million US dollars, which was growing at a rate of 30% per year. At that time, it was estimated that in 2004, the export volume of household electronic scales would exceed 50 million units and the export value would exceed 200 million U.S. dollars. Based on this export volume, in 2004, a total of 120 million household electronic scale weighing sensors were produced, and the corresponding resistance strain gauge (calculated as a single-axis slice) was approximately 480 million pieces.
After many years of research and production practices, the difficulties in the manufacturing process, such as the small range of the load cell, the small elastic body, and the small size of the resistance strain gauge sensitive grid, have been solved. Because the accuracy of the home electronic scale load cell is ordinary, and no circuit compensation is required, mass production is required. Generally, more than 120,000 electrical resistance strain gauges and more than 30,000 load cells are used in the production plants with medium or more types. They solved this problem with high-quality self-compensating resistance strain gauges with high-quality temperature and modulus, creating conditions for mass production of household electronic scale load cells.
IV. Recent developments in the development of load cell technology in the world There are two major development paths in the world: the United States as the representative of the military before and after the civilian use, the first to increase the popularization of the way and the commercialization of the commercialization represented by Japan, first popularized after the increase Way. China should belong to the latter. Although the military industry researched and applied earlier, it has not been converted to civilian use. Rapid development and popularization have been in the past 20 years. In recent years, it is a critical period, and it is urgent to improve the overall technology, process, and quality of our load cells.
The development trend of international load cell technology is to regard the accuracy, stability, and reliability of the load cell as an extremely important quality indicator. The manufacturing technology and manufacturing process are used as the core competitiveness, and the characteristics of the load cell are firmly grasped. Basic research, process research, and applied research on issues, production problems, and applied problems, and their research directions and characteristics are:
(1) In the product structure design and manufacturing process, the computer simulation technology and virtual technology in engineering product design were drawn up to speed up the development and reduce the development risk;
(2) In the processing of elastomers, from cell processing technology to integrated processing technology; from rigid manufacturing development to flexible manufacturing; from simplification of empirical judgment development to intelligent quantitative analysis. Universal use of flexible manufacturing units and flexible manufacturing systems;
(3) The production process is not a “workshop craft†in traditional Guan Nian, but a systematic project combining technology and management. In order to adapt to multi-variety, high-volume production and ensure the homogeneity of the technical performance of the product, the production process must minimize manual operations and artificial control, and increase the direction of semi-automated and automated processes. For example: computer control, man-machine integration process system and test technology networked information system;
(4) Stable treatment process related to stability and reliability Based on the methods of high-temperature treatment, cryogenic cryogenic, pulsating fatigue, and overload static pressure, a new process of vibration aging and resonance aging was developed. The resonance was performed for 10 minutes. Eliminate most of the residual stress.
With the above-mentioned design and manufacturing technology support, the variety and structure of the load cell are innovative, and the technical function and application range are continuously expanding. The main results are:
(1) U.S. Revere Corporation developed the PUS type load cell with pressure and pressure compensation function for high accuracy test platform and weighing platform with an accuracy of up to 5000d;
(2) German HBM company successfully developed C1A, C16A two different structures of 1-100t explosion-proof load cell with "pressure shell" protection, its explosion-proof performance in line with European EN50014 and EN50018 "d" level standards;
(3) U.S. Scaime developed a new generation of high accuracy stainless steel F60X series 5-5000kg load cell with an accuracy of 6000d. Used in high humidity, corrosive environment, and waterproof;
(4) The German Setner company developed a 200-type load cell for rapid weighing using beryllium bronze as an elastomer material. It is characterized by good linearity, high natural frequency, and fast dynamic response. The original oil damping device is integrated with the overload protection device to ensure fast speed and long working life. Assembly 3 a 30kg electronic platform scale, accuracy up to 4000d;
(5) The United States THI company developed 1410 type 5 a 30kg aluminum alloy load cell, the accuracy level is better than the C3 level, can withstand centrifugal force and mechanical vibration, built-in special viscous dampers, to ensure a faster stability when weighing Time, generally less than 50ms;
(6) U.S. VT BLH developed a new weigh module with reasonable componentized functions and extremely high weighing efficiency. After being shipped from the factory, it can be “plug and play†and can automatically adjust the position without stirring, eccentricity, and vibration. influences.
Only the above examples are sufficient to represent the direction of the development of new products and reflect the technological advancement and advanced technology. In terms of technical content, there are high-accuracy (4000d-6000d) load cell manufacturing technologies; atmospheric pressure compensation technology; quick and dynamic measurement of viscous dampers for load cells; flameproof pressure-resistant enclosures Design and manufacturing technology; modularization of new modular design technologies.
Fifth, the development trend of load cell technology The trend of strain-type load cell can be summarized by “four modernizationsâ€, that is, virtualization of design technology, flexibility of manufacturing technology, networking of production process, and informatization of enterprise management.
Virtualization of design technology: Virtual technology including the virtual reality technology design and process design. Structural simulation technology: refers to the structural and performance analysis techniques for elastomers, including dynamic simulation, dynamic analysis, calculation of strength and stiffness finite element method, strain size and distribution of sensitive areas, etc., in order to achieve the purpose of optimal design.
Process design virtual technology: refers to the simulation and testing of the elastomer production process, testing the processability of the elastomer, the rationality of processing methods and processes, and ensuring the optimization of the manufacturing process.
The core of design technology virtualization is finite element calculation and computer dynamic simulation. Simulation software is used to simulate real load conditions, identify and deal with design and process defects or errors in a timely manner to ensure the rationality of structural design and production processes.
Flexibility of manufacturing technology: It refers to the integration of advanced manufacturing technologies in the processing of multi-species and mass-produced elastomers: flexible manufacturing units (FMC), flexible manufacturing systems (FMS) and computer integrated manufacturing systems. It is a brand-new manufacturing system formed by combining computer technology, information technology, automatic control technology and traditional manufacturing technology.
Networking of production process: refers to the connection of computer systems with independent operation and control functions in each production process through communication lines and equipment during the entire process of production process. Under the management of network software, information collection, storage and processing are realized. . Compared with the traditional “workshop craft†production process, manual operations are greatly reduced, and the influence of human factors on product quality is eliminated to the maximum extent.
Enterprise management informationization refers to the establishment of an enterprise information system based on the requirements of computer processing, based on structured system analysis and design methods, and the comprehensive modernization of enterprise management. Including CAD, CAM system, production management system, business decision-making system and business management system.
In order to adapt to the development of electronic weighing technology from static weighing to dynamic weighing, the measurement method has evolved from analog measurement to digital measurement; measurement characteristics have evolved from single-parameter measurement to multi-parameter measurement development, and new requirements for electronic weighing instruments for weighing sensors. It will be the focus of research and development in the coming period:
Fast, low-speed dynamic and dynamic load cells and their damping technology;
Multi-functional, multi-component weighing sensors and their testing methods;
Small and ultra-large-scale load cells;
Explosion-proof, pressure resistance, corrosion resistance and other weighing sensors;
Eccentric load measurement and weighing sensor for vehicle scales;
Large resistance, low power consumption, high precision resistance strain gauge, etc.
Analyzing the new requirements of electronic weighing instruments for weighing sensors in recent years, it is not difficult to conclude that miniaturization, integration, multi-functionalization and intelligence will be the important features and development trends of load cells.
Miniaturization: It means that the overall structure of the load cell is small in size, low in height and light in weight, ie small, thin, and light. For example: 30t, 60t bending ring structure, its external dimensions are 120mm and 150mm outside diameter, height is only 50mm and 60mm.
Integration: There are two forms of structural integration and functional integration. Structural integration refers to a new type of structure in which the elastic body and the scale body are combined, for example, a weighing plate, a weighing rail, a weighing hook, a weighing ring, and the like. Functional integration refers to weighing sensors that collect, amplify, transform, transmit, process, and display weight information, such as: sensors (elastomers), conversion elements (resistance strain gauges), signal processing circuits, and weighing devices. The display control is integrated in the spoke type weighing sensor, and its digital display position is located at the junction box of the conventional spoke type weighing sensor, which is commonly called a spoke type weighing instrument.
Multi-function: It means that the load cell itself can detect other information at the same time in addition to the function of detecting weight information. For example: the electronic crane weighing sensor can detect the acceleration information while detecting the weight information; the vehicle detection platform uses a load cell that can simultaneously detect the vertical direction of the weight information and the horizontal direction of the lateral load, that is, multi-component force measurement.
In 1940, American A.Thurston (Thurston), the chief engineer of BLH and Revere company, developed a cylindrical strain gauge load cell using SR-4 strain strain gage. It was used in engineering force measurement and weighing measurement to become a strain load. The founder of the sensor. In 1942, strain load sensors in the United States were mass-produced and have been in existence for more than 60 years.
For the first 30 years or more, it is the world of the load cell with column, cylinder, ring, and beam structure using normal stress (tension, compression, and bending stress). During this period, the British scholar Jackson developed a metal foil resistance strain gauge, which provided an ideal conversion element for the load cell and created a new process for attaching a resistance strain gauge with thermosetting glue. After years of practice, BLH and Revere have created load sensor circuit compensation and adjustment processes to improve the accuracy and stability of the load cell. The accuracy has increased from a few percent in the 1940s to a 0.05 in the early 1970s. Magnitude. However, the problems in the application process are also very prominent, mainly: the increase in force point will cause a relatively large sensitivity changes; simultaneous pull, pressure cycle load sensitivity deviation; anti-offset and lateral load capacity is poor; can not be small Load measurement. The above disadvantages severely restrict the development of load sensors.
After more than 30 years, experienced two major technological breakthroughs in the 70s shear stress load sensor and aluminum alloy small-scale load sensor; in the 1980s, the load cell and load cell were completely separated, formulated R60 international recommendations and developed a digital smart load cell. Two major reforms; in the 90's in the structural design and manufacturing process continue to incorporate high-tech to meet new challenges and accelerate the development of load cell technology.
In 1973, American scholar Hogsttem proposed to overcome the intrinsic shortcomings of normal stress load sensors and proposed to use the shear stress independent of the bending moment to design the load sensor theory without using normal stress, and to design a circular I-section cantilever shear Cut beam type load cell. Breaking the world of normal stress load sensors has formed a new trend of development. This is a major breakthrough in the design of load cell structures.
Around 1974, American scholar Stein and German scholar Edom proposed the establishment of a more complex mechanical model of elastic body. Using finite element calculation method, the strength, stiffness, stress field and displacement field of the elastic body were analyzed to obtain the optimal design. . A new approach has been opened up for the design and calculation of load sensors using modern analysis methods and calculation methods.
In the mid-1970s, weighing instrument manufacturing companies in the United States, Japan, and other countries began to develop commercial electronic pricing scales, which are in urgent need of small-range load sensors. Traditional normal stress and newly developed shear load sensors cannot achieve measurements in the range of several kilograms to several tens of kilograms. Schatz, an American scholar, proposed using aluminum alloys with low elastic modulus as elastic bodies and using multi-beam structures to solve the contradiction between sensitivity and stiffness. A small-range aluminum alloy parallel beam load cell was designed. It was also pointed out that the parallel beam load cell was based on the principle of constant bending moment, which makes use of the normal stress structure of the parallel beam surface bending stress, and has the characteristics of shear stress load sensor, which is a parallel beam structure. The design and calculation of load sensors laid a theoretical foundation and formed another development trend.
Creep is a key issue that resistance strain gauges and aluminum alloy load sensors often encounter and must address. Before 1978, the Soviet scholar Kolokokova analyzed the one-dimensional mechanical model and the strain transfer coefficient, and proposed the ratio of the gate width and grid width of the resistance strain gage sensitive grid to make different creep resistance strain gages. The theory, and successfully developed a series of creep compensation strain gauges. It plays a crucial role in reducing creep error and improving accuracy for low-capacity aluminum alloy load sensors, making it possible to use aluminum alloy load sensors with multiple varieties and mass production for electronic pricing scales.
Due to the rapid development of electronic weighing technology, the evaluation method of load sensor performance can no longer meet the needs of using ladder tolerance zone to assess the accuracy of electronic weighing scales, and urgently needs measurement procedures that are compatible with the accuracy evaluation methods of electronic weighing instruments. In the early 1980s, the Office of International Legal Metrology (OIML) Quality Measurement Guidance Secretariat decided to completely separate the sensors for electronic weighing from the sensors used for force measurement. The 8th report secretariat drafted by the United States drafted “Weighing sensor measurement. Procedures. After a written vote by OIML member states, it was formally approved at the 7th Legal Metrology Conference in October 1984, and was issued in 1985 with the OIML, R60 international recommendations and was issued to all member states. At present, the countries are implementing the 2000 version of the R60. It can be said that R60 "weighing sensor measurement procedures" is a "passport" for weighing sensors in various countries to enter the international market.
With the development of digital technology and information technology, the demand for digital electronic scales in various industries is increasing. It is proposed that digital weighing systems break through the limitations of analog weighing systems, and analog load sensors cannot do anything about this. Because before this, the research of the weighing sensor is all concentrated on the hardware aspect, for example: Innovate the structure of the elastomer, improve the manufacturing craft, improve the circuit to compensate and adjust and so on. The output signal of the analog load cell is small, the anti-jamming capability is poor, the transmission distance is short, the weighing display control instrument is complex, and the shortcomings such as the long debugging period of the group scale remain the same. In order to meet the demand of digital electronic scales, the United States TOLEDO, STS and CARDINAL companies, Germany HBM companies have developed integrated and separate digital intelligent load cells, and with its large output signal, anti-interference ability, signal transmission distance Far, easy to implement intelligent control and other characteristics, become digital electronic weighing and automatic weighing measurement and control system must be selected products, forming a hot spot for development.
In the 1990s, due to the maturation of basic technologies such as the design and calculation of load cells, the development of load cells was focused on process research and applied research. There were product standardization, serialization, engineering design, and large-scale production processes. Great progress, mainly:
Introduce computer simulation technology and virtual technology in structure and process design;
Incorporation of flexible manufacturing technology in elastomer processing;
Use computer network technology in the production process;
Transplantation of vibration aging and new resonance aging process in stable treatment;
Automatic quick detection and dynamic comparison methods were created in test verification.
Breakthrough progress has also been made in the application of technology: on the basis of traditional weighing modules, new weighing modules have been developed. This is a typical product that uses new technologies to face new challenges. Its characteristic is componentized design, with "plug and play" function, can reduce the weight error due to weight, thermal effects, accidental overload, etc., and can withstand the bias caused by vibration, impact, agitation or other external forces. In short, two technological breakthroughs in the 1970s, two major changes in the 1980s, and the concept of research and development that incorporated new high technologies in the 1990s to face new challenges have greatly promoted the development of load cell technology.
Second, the status quo of foreign load cell technology and rapid development reasons Industrial and commercial electronic weighing scales with load cell technology and manufacturing processes, the United States, Germany and other famous industrial companies in developed countries in the leading position in the international market leader, China has a certain scale The weighing sensor manufacturing company is in the market challenger or market follower status. The R&D and production center for load cells for household electronic scales is in China. In Shenzhen, the manufacturing technology, technological level, product quality and annual output have increased year by year.
The competition in today's international market for load cell technology focuses on competition in product accuracy, stability, and reliability; competition between manufacturing technology and manufacturing processes; and application of high-tech research and development for new products and competition for proprietary intellectual property products. Each weighing sensor manufacturing company is striving to cultivate its own core competitive technology and build core competitive products.
From the products exhibited at the International Weighing Instruments Industry Exhibition in recent years and the analysis of the products of a number of market leaders, it can be concluded that the common pursuit of these companies is that the elastomer materials are more sophisticated; the resistance strain gauges and compensation elements The device's technical requirements and environmental stress screening are more stringent; the manufacturing process is more refined; the circuit compensation process is more complete; and the appearance quality is more perfect.
The accuracy, stability, and reliability of the load cell are important quality indicators. At the same time, they are also of the most concern to the user. In response, these companies have conducted many research and experimental work in structural design, manufacturing processes, circuit compensation and adjustment, and stability handling, and have made significant progress. The main achievements are:
(1) In the process of structural design and calculation, computer simulation technology was introduced to carry out dynamic simulation and dynamic analysis. Computer simulation technology was introduced into the process design process to simulate and test the elastomer production process.
(2) In the processing of elastomers, advanced manufacturing technologies are incorporated, and rigid manufacturing is changed to flexible manufacturing. Universal use of machining centers, flexible manufacturing units, and flexible manufacturing systems;
(3) In the whole production process, manual operation and artificial control are minimized, semi-automatic and automatic control and automatic inspection procedures are added, and computer network technology is used in the production process;
(4) Improve and innovate process equipment to achieve highly efficient intelligent circuit compensation, establish a fully automatic rapid inspection system, and improve the success rate of C3 grade products and the sampling qualification rate of mass production products;
(5) Transplant advanced stable processing technologies and equipment, implement new processes of vibration aging or resonance aging, and improve the long-term stability and reliability of the load cell;
(6) Apply new and high technology to develop new products and independent intellectual property rights products to enhance core competitiveness. Companies in the leading position in the international market have their own core competitive technologies, processes and products, such as: "O creep" load cells for positive and negative creep bridges; bronze dynamic load cells; integral and discrete digital Smart load cell; high-accuracy stainless steel 3-column, 4-column high-temperature load cell; modularized plug-and-play new-type weighing module.
The development characteristics of foreign load cell technology and the reasons for rapid development:
(1) Pay attention to the research of basic technologies, basic technologies and common key technologies. Do basic research and pre-research in parallel. Common key technology research and applied technology research in parallel. Typical product development and product engineering in parallel. Ensure that the basic technology and basic processes (resistance strain gauges, strain adhesives, compensation components, protective and sealing materials, etc.) have been in the world's leading position.
(2) Emphasize the research and application of infrastructure construction and manufacturing technologies and manufacturing processes. Good configuration of technical equipment and testing equipment, especially intelligent process equipment, made the most advanced technology and equipment;
(3) To describe the development trend and strategic frontier of the world weighing sensor technology, and to determine the research topics and product development direction. Emphasis on the development of new products and proprietary intellectual property products and enhance core competitiveness. The standards of its technological innovation and new product development are: high technical lead, advanced technology, market proliferation, and efficiency proliferation. Make technology and process always lead the world.
(4) Emphasize the reliability design, control and management of the load cell, strictly design the conformity control and process reliability control, and strive to achieve 100% of the process redemption rate.
(5) Pay attention to market competition, strengthen market investigation and analysis, and quickly respond to the market. In the 21st century, market competition is focused on market response speed and based on improved and innovative products.
(6) Pay attention to the study of relevant laws and regulations, fully understand and implement them carefully, and ensure that every product produced meets the requirements.
Because of this, a wide variety of foreign load cells, complete specifications, alloy steel, aluminum alloy, stainless steel, bronze bronze products are everything; underwater, under the drilling measurement, pressure explosion-proof, anti-radiation, anti-corrosion products; small and ultra-large-scale ; Weighing and dynamic weighing; integrated and modular structure for any user to buy. In addition, both the internal and external quality of the product are emphasized. In recent years, the appearance quality has been improved and improved. There are basically no paint products, and almost all of them are bright or matte chemical nickel plating, chrome plating, paint, plastic spray, and porcelain anodization. Stainless steel products. The shape of individual products has been integrated into humanized design.
The current research and development hotspots are:
Digital compensation technology and compensation technology of digital smart load cell, and its application technology;
Rapid, low-speed dynamic and dynamic load cell development and damping technology;
High temperature load cell manufacturing process, high temperature stability and application technology;
Pressure and explosion proof load cell and pressure shell design and test technology;
"Plug & Play" new weigh modules for modular design;
Using helium and neon instead of nickel to make sensitive temperature compensation resistors.
Third, the status of China's load cell technology and the main gap Although China's aviation and aerospace industry as early as the late 1950s began to study the application of strain-type load sensors, but did not develop for civilian use. As far as the whole country is concerned, the development and production of load sensors started late. In the 1960s, only a few manufacturers produced strain gauge load cells with ordinary precision grades. The structure is single, only two structures, cylindrical, circular, basically do not carry out circuit compensation and adjustment, some products even use the external balance box to adjust the zero point.
In the early 1980s, more than 20 companies throughout the country spent 100 million yuan to use Swindon's 13 million U.S. dollars to import strain gauge load sensor manufacturing technology and equipment from the United States and Japan to learn, digest, and absorb. After imitation and trial production, many varieties of small batch production began, and after the market was launched, considerable benefits were achieved. At that time, people concluded that this product is: more varieties, small quantities, low cost, high yield, less investment, and quick results. The attention of individuals and enterprises in many industries has entered this industry. Manufacturers have rapidly increased from more than 20 in the 1970s to more than 100, and the annual output is equivalent to that in Japan, reaching more than 1 million.
With the development of the national economy, the demand for electronic scales in various industries has continuously increased, which has greatly promoted the development of load cell technology. From the mid-1980s to the mid-1990s, it was a decade in which the technology of weighing sensors in China has developed steadily, and the varieties and specifications have rapidly increased and the quality of products has been continuously improved. Many manufacturers have improved or added process equipment and instrumentation, purchased intelligent temperature compensation devices and sensitivity temperature compensation equipment, and achieved large-scale production. In the mid-1990s, the number of weighing sensor manufacturers increased to more than 160, with an annual output of more than 2 million. In addition to meeting the needs of the domestic market, more than a dozen companies began exporting in small quantities, showing a good momentum of development.
Although weighing sensors are legally-measured measuring instruments that are subject to mandatory management by the state, they should be more difficult to enter the industry. However, due to various reasons, it is easy for some enterprises and individuals to enter, causing market congestion and exacerbating market competition. Finally the price war broke out in the mid-1990s. The price was low, and whoever was the big winner, and the year-by-year escalation became even more fierce. The evil consequences of price wars are slow technological progress, declining technological levels, serious quality problems, and uncontrolled management supervision. The initial victims were the vast majority of users. The ultimate victim was the company itself and was the entire weighing sensor industry. With these issues entering the 21st century, the gap between the weighing sensors and the industrialized countries has not narrowed, but has increased. The results of the national supervision and spot checks in recent years are examples.
In 2002, the state supervised and spot-checked 7 provinces and cities, 16 enterprises, a total of 48 weighing sensors, and qualified 18, with a pass rate of 37.5%. Thirty unqualified products came from 10 companies. The reason for the failure was all the poor temperature performance. What is more serious is that of the 16 companies, only one company strictly implements the national standards. If you change to a full inspection, the pass rate will be lower. The results of national supervision and spot checks have truly reflected the overall technology, process and management level of China's load cells. The main reasons for the low pass rate are: poor quality awareness, not organized production according to law; no understanding or implementation of R60 international recommendations and national standards, equating 0.02 and C3 levels erroneously; changing materials and replacing components under profit drive , reduce the process, only for barely qualified or artificially qualified.
The main gap between China's load cells and industrial advanced countries in the market leading position of enterprise products is:
(1) There are few types of structures, incomplete specifications, and scarcity of special-purpose products;
(2) The accuracy level is low, and the success rate of C3 level is not high;
(3) Poor stability and reliability, high repair rate, and low working life;
(4) The level of product standardization, engineering, and the degree of industrialization of enterprises are low, and the uniformity of product technical indicators is poor;
(5) Although the appearance quality has improved, there is still a large gap;
(6) Technology equipment and testing methods are not advanced enough and are not matched. The manual operation and artificial control components in the production process are large. The “workshop art†has deep traces, and human factors have a greater impact on product quality;
(7) There are few innovative products and independent intellectual property products, and there are many low-level repeated products, and there are few OEM products and direct export products;
(8) The company does not have core competitive technologies and products. The market survey is not enough, and the market response is too slow, resulting in the inability to integrate with the international market.
In short, the manufacturing process has the largest gap, and the manufacturing process is usually divided into:
Supporting processes for elastomer forging, machining, heat treatment and surface treatment;
Basic processes - resistance strain gauges, strain adhesives, circuit compensation components, and protective sealing materials;
Core process - resistance strain gauge paste and curing, zero point and sensitivity, intelligent temperature compensation and protection and sealing;
Special process one by one heat treatment aging process and mechanical stabilization process.
The gap between the basic process and the special process is the largest.
Household electronic scales (body scales, health scales, fat scales, kitchen scales, nutrition scales, treasure scales, pocket scales, hand-held scales, etc.) Weighing sensors and their resistance strain gauges. Since the mid-1990s, research and development and production have come from the world. Countries gradually moved to China, mainly in Guangdong and Shenzhen. In recent years, shocking developments in design technology, manufacturing processes and product output have been made. There are three types of production companies: one is the design, production, and assembly of various household electronic scales; the other is the production of various load cells (or self-produced strain gages or outsourced strain gages) for home electronic scales. Three of them produce resistance strain gages for household electronic scale load cells. At present, these three types of manufacturers have reached more than 60. According to the statistics of the country's customs, in 2003, the export volume of household electronic scales was over 38.6 million units, and the export value was 147 million US dollars, which was growing at a rate of 30% per year. At that time, it was estimated that in 2004, the export volume of household electronic scales would exceed 50 million units and the export value would exceed 200 million U.S. dollars. Based on this export volume, in 2004, a total of 120 million household electronic scale weighing sensors were produced, and the corresponding resistance strain gauge (calculated as a single-axis slice) was approximately 480 million pieces.
After many years of research and production practices, the difficulties in the manufacturing process, such as the small range of the load cell, the small elastic body, and the small size of the resistance strain gauge sensitive grid, have been solved. Because the accuracy of the home electronic scale load cell is ordinary, and no circuit compensation is required, mass production is required. Generally, more than 120,000 electrical resistance strain gauges and more than 30,000 load cells are used in the production plants with medium or more types. They solved this problem with high-quality self-compensating resistance strain gauges with high-quality temperature and modulus, creating conditions for mass production of household electronic scale load cells.
IV. Recent developments in the development of load cell technology in the world There are two major development paths in the world: the United States as the representative of the military before and after the civilian use, the first to increase the popularization of the way and the commercialization of the commercialization represented by Japan, first popularized after the increase Way. China should belong to the latter. Although the military industry researched and applied earlier, it has not been converted to civilian use. Rapid development and popularization have been in the past 20 years. In recent years, it is a critical period, and it is urgent to improve the overall technology, process, and quality of our load cells.
The development trend of international load cell technology is to regard the accuracy, stability, and reliability of the load cell as an extremely important quality indicator. The manufacturing technology and manufacturing process are used as the core competitiveness, and the characteristics of the load cell are firmly grasped. Basic research, process research, and applied research on issues, production problems, and applied problems, and their research directions and characteristics are:
(1) In the product structure design and manufacturing process, the computer simulation technology and virtual technology in engineering product design were drawn up to speed up the development and reduce the development risk;
(2) In the processing of elastomers, from cell processing technology to integrated processing technology; from rigid manufacturing development to flexible manufacturing; from simplification of empirical judgment development to intelligent quantitative analysis. Universal use of flexible manufacturing units and flexible manufacturing systems;
(3) The production process is not a “workshop craft†in traditional Guan Nian, but a systematic project combining technology and management. In order to adapt to multi-variety, high-volume production and ensure the homogeneity of the technical performance of the product, the production process must minimize manual operations and artificial control, and increase the direction of semi-automated and automated processes. For example: computer control, man-machine integration process system and test technology networked information system;
(4) Stable treatment process related to stability and reliability Based on the methods of high-temperature treatment, cryogenic cryogenic, pulsating fatigue, and overload static pressure, a new process of vibration aging and resonance aging was developed. The resonance was performed for 10 minutes. Eliminate most of the residual stress.
With the above-mentioned design and manufacturing technology support, the variety and structure of the load cell are innovative, and the technical function and application range are continuously expanding. The main results are:
(1) U.S. Revere Corporation developed the PUS type load cell with pressure and pressure compensation function for high accuracy test platform and weighing platform with an accuracy of up to 5000d;
(2) German HBM company successfully developed C1A, C16A two different structures of 1-100t explosion-proof load cell with "pressure shell" protection, its explosion-proof performance in line with European EN50014 and EN50018 "d" level standards;
(3) U.S. Scaime developed a new generation of high accuracy stainless steel F60X series 5-5000kg load cell with an accuracy of 6000d. Used in high humidity, corrosive environment, and waterproof;
(4) The German Setner company developed a 200-type load cell for rapid weighing using beryllium bronze as an elastomer material. It is characterized by good linearity, high natural frequency, and fast dynamic response. The original oil damping device is integrated with the overload protection device to ensure fast speed and long working life. Assembly 3 a 30kg electronic platform scale, accuracy up to 4000d;
(5) The United States THI company developed 1410 type 5 a 30kg aluminum alloy load cell, the accuracy level is better than the C3 level, can withstand centrifugal force and mechanical vibration, built-in special viscous dampers, to ensure a faster stability when weighing Time, generally less than 50ms;
(6) U.S. VT BLH developed a new weigh module with reasonable componentized functions and extremely high weighing efficiency. After being shipped from the factory, it can be “plug and play†and can automatically adjust the position without stirring, eccentricity, and vibration. influences.
Only the above examples are sufficient to represent the direction of the development of new products and reflect the technological advancement and advanced technology. In terms of technical content, there are high-accuracy (4000d-6000d) load cell manufacturing technologies; atmospheric pressure compensation technology; quick and dynamic measurement of viscous dampers for load cells; flameproof pressure-resistant enclosures Design and manufacturing technology; modularization of new modular design technologies.
Fifth, the development trend of load cell technology The trend of strain-type load cell can be summarized by “four modernizationsâ€, that is, virtualization of design technology, flexibility of manufacturing technology, networking of production process, and informatization of enterprise management.
Virtualization of design technology: Virtual technology including the virtual reality technology design and process design. Structural simulation technology: refers to the structural and performance analysis techniques for elastomers, including dynamic simulation, dynamic analysis, calculation of strength and stiffness finite element method, strain size and distribution of sensitive areas, etc., in order to achieve the purpose of optimal design.
Process design virtual technology: refers to the simulation and testing of the elastomer production process, testing the processability of the elastomer, the rationality of processing methods and processes, and ensuring the optimization of the manufacturing process.
The core of design technology virtualization is finite element calculation and computer dynamic simulation. Simulation software is used to simulate real load conditions, identify and deal with design and process defects or errors in a timely manner to ensure the rationality of structural design and production processes.
Flexibility of manufacturing technology: It refers to the integration of advanced manufacturing technologies in the processing of multi-species and mass-produced elastomers: flexible manufacturing units (FMC), flexible manufacturing systems (FMS) and computer integrated manufacturing systems. It is a brand-new manufacturing system formed by combining computer technology, information technology, automatic control technology and traditional manufacturing technology.
Networking of production process: refers to the connection of computer systems with independent operation and control functions in each production process through communication lines and equipment during the entire process of production process. Under the management of network software, information collection, storage and processing are realized. . Compared with the traditional “workshop craft†production process, manual operations are greatly reduced, and the influence of human factors on product quality is eliminated to the maximum extent.
Enterprise management informationization refers to the establishment of an enterprise information system based on the requirements of computer processing, based on structured system analysis and design methods, and the comprehensive modernization of enterprise management. Including CAD, CAM system, production management system, business decision-making system and business management system.
In order to adapt to the development of electronic weighing technology from static weighing to dynamic weighing, the measurement method has evolved from analog measurement to digital measurement; measurement characteristics have evolved from single-parameter measurement to multi-parameter measurement development, and new requirements for electronic weighing instruments for weighing sensors. It will be the focus of research and development in the coming period:
Fast, low-speed dynamic and dynamic load cells and their damping technology;
Multi-functional, multi-component weighing sensors and their testing methods;
Small and ultra-large-scale load cells;
Explosion-proof, pressure resistance, corrosion resistance and other weighing sensors;
Eccentric load measurement and weighing sensor for vehicle scales;
Large resistance, low power consumption, high precision resistance strain gauge, etc.
Analyzing the new requirements of electronic weighing instruments for weighing sensors in recent years, it is not difficult to conclude that miniaturization, integration, multi-functionalization and intelligence will be the important features and development trends of load cells.
Miniaturization: It means that the overall structure of the load cell is small in size, low in height and light in weight, ie small, thin, and light. For example: 30t, 60t bending ring structure, its external dimensions are 120mm and 150mm outside diameter, height is only 50mm and 60mm.
Integration: There are two forms of structural integration and functional integration. Structural integration refers to a new type of structure in which the elastic body and the scale body are combined, for example, a weighing plate, a weighing rail, a weighing hook, a weighing ring, and the like. Functional integration refers to weighing sensors that collect, amplify, transform, transmit, process, and display weight information, such as: sensors (elastomers), conversion elements (resistance strain gauges), signal processing circuits, and weighing devices. The display control is integrated in the spoke type weighing sensor, and its digital display position is located at the junction box of the conventional spoke type weighing sensor, which is commonly called a spoke type weighing instrument.
Multi-function: It means that the load cell itself can detect other information at the same time in addition to the function of detecting weight information. For example: the electronic crane weighing sensor can detect the acceleration information while detecting the weight information; the vehicle detection platform uses a load cell that can simultaneously detect the vertical direction of the weight information and the horizontal direction of the lateral load, that is, multi-component force measurement.