A self-calibrating micro force sensor

Abstract

The utility model discloses a kind of miniature force transducer of exemption calibration, it is related to miniature force transducer technical field, including sensor main body, the side of sensor main body is electrically connected with communication component, communication component includes connector and parameter storage module, parameter storage module is electrically connected between sensor main body by cable, parameter storage module has stored sensitivity specific value, the sensitivity specific value of sensor factory calibration is pre-stored by parameter storage module, to replace artificial weight calibration process, simultaneously, parameter storage module can avoid artificial operation error, sensitivity deviation is reduced from original ±2%F.S.to ±0.05%F.S., avoid 3C product contact pressure injury caused by calibration error.

Description

Technical Field

[0001] This utility model relates to the field of miniature force sensor technology, and in particular to a calibration-free miniature force sensor. Background Technology

[0002] In the current field of precision manufacturing, especially in scenarios such as 3C product assembly, automotive electronic contact installation, and precision calibration of medical devices, miniature force sensors are the core components for achieving closed-loop control of contact force. Force sensors need to accurately monitor and control the force values ​​in processes such as contact pressing and bonding to ensure good contact without damaging the workpiece. The typical force control range of force sensors covers 300-1500g. As the industry's requirements for production efficiency, accuracy consistency, and scenario adaptability increase, existing miniature force sensors have gradually exposed many technical defects, making it difficult to meet the production needs of high efficiency, high precision, and high reliability in precision manufacturing.

[0003] Currently, the most widely used type of force sensor in the industry is the miniature strain gauge type. This sensor is mainly suitable for contact pressing and bonding scenarios in 3C product assembly lines. Its core structure is an aluminum alloy elastomer integrated strain gauge. The signal and power are connected by cable welding. It does not have automatic parameter storage and calibration-free functions, and calibration and maintenance need to be completed manually.

[0004] The existing sensors lack TEDS functionality and cannot automatically store calibration parameters such as sensitivity. Each time the machine is powered on or the sensor is replaced, manual calibration using standard weights is required. The entire calibration process takes up to half an hour to an hour, which seriously affects the efficiency of production line startup and changeover. Furthermore, the operational error of manually loading weights can lead to a sensitivity deviation of ±2%FS, resulting in quality problems such as contact damage or poor contact.

[0005] To address the above shortcomings, further improvements are needed to the force sensor to mitigate the sensitivity errors caused by the need for manual calibration. Utility Model Content

[0006] This invention aims to overcome the problem of sensitivity errors in force sensors due to the need for manual calibration, and provides a calibration-free miniature force sensor.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a calibration-free miniature force sensor, comprising a sensor body, a communication component electrically connected to one side of the sensor body, the communication component comprising a connector and a parameter storage module, the parameter storage module being electrically connected to the sensor body via a cable, and the parameter storage module storing specific sensitivity values.

[0008] As a further embodiment of this utility model: the sensor body is provided with a strain acquisition module inside, and the strain acquisition module is electrically connected to the parameter storage module.

[0009] As a further embodiment of this utility model: the end of the cable away from the parameter storage module passes through the sensor body and is fixedly connected to one side of the strain acquisition module.

[0010] As a further embodiment of this utility model: the sensor body has a deformation gap for deformation of the sensor body, and the sensor body has an opening, with one end of the deformation gap communicating with the opening.

[0011] As a further embodiment of this utility model: there are two deformation gaps, which are located on both sides of the sensor body, and the cross-sections of the two deformation gaps are in the shape of a broken line or a meandering shape.

[0012] As a further embodiment of this utility model: the connector and the parameter storage module are integrally formed, and a protective sleeve is provided on the outside of the connector.

[0013] As a further embodiment of this utility model: the sensor body is made of stainless steel, the height of the sensor body is 17-22mm, and the length of the sensor body is 14-18mm.

[0014] As a further embodiment of this utility model: the upper surface of the sensor body is the force-bearing surface, the lower surface of the sensor body is the placement surface, and an accommodating space is provided at the axis of the sensor body, with the strain acquisition module located inside the accommodating space.

[0015] As a further embodiment of this utility model: the parameter storage module is a TEDS parameter storage module, the connector is an aviation plug, and the fixed connection between the cable and the strain acquisition module is covered with epoxy resin.

[0016] As a further embodiment of this utility model: the sensor body has a flat rectangular shape, the sensor body is a stainless steel elastomer, and the strain acquisition module also includes a closed-loop signal processing module.

[0017] Compared with existing technologies, the advantages of this technical solution are as follows: the specific sensitivity values ​​of the sensor calibrated at the factory are pre-stored by the parameter storage module, thereby replacing the manual weight calibration process. At the same time, the parameter storage module can avoid human operation errors and prevent damage to the contacts of 3C products caused by calibration errors.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the strain acquisition module of this utility model; Figure 3 This is a schematic diagram of the communication component structure of this utility model; Figure 4 This is a side view of the overall structure of this utility model; Figure 5 yes Figure 4 Schematic diagram of the cross section at point AA; Figure 6 This is a schematic diagram of the pin distribution of the plug of this utility model; Figure 7 yes Figure 6 Diagram showing the pin definitions of the plug. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] Please see Figure 1-7 A calibration-free miniature force sensor includes a sensor body 1. A communication component 2 is electrically connected to one side of the sensor body 1. The communication component 2 includes a connector 21 and a parameter storage module 22. The parameter storage module 22 is electrically connected to the sensor body 1 via a cable 3. The parameter storage module 22 stores specific sensitivity values. By using the specific sensitivity values ​​pre-stored in the parameter storage module, the manual weight calibration process can be replaced. At the same time, the parameter storage module can avoid human operation errors and reduce the sensitivity deviation from the original ±2%FS to ±0.05%FS, avoiding damage to the contacts of 3C products caused by calibration errors.

[0023] In some embodiments: The sensor body 1 is provided with a strain acquisition module 11 inside. The strain acquisition module 11 is electrically connected to the parameter storage module 22. The core function of the parameter storage module is to pre-store the specific sensitivity value of the sensor. This value is calibrated and written by a standard calibration device before the sensor leaves the factory to ensure the accuracy of the parameters. The parameter storage module 22 will automatically transmit the stored sensitivity parameters to the external actuator controller. The controller, combined with the electrical signal output by the strain acquisition module 11, will directly calculate the accurate force value without the need for manual loading of weights for calibration.

[0024] Specifically: the end of the cable 3 away from the parameter storage module 22 passes through the sensor body 1 and is fixedly connected to one side of the strain acquisition module 11. The cable 3 serves as the circuit connection medium between the sensor body 1 and the communication component 2, forming a complete signal transmission path, and at the same time provides power to the strain acquisition module 11.

[0025] Furthermore, the sensor body 1 is provided with a deformation gap 12 for deformation of the sensor body 1, and an opening 13 is provided on the sensor body 1. One end of the deformation gap 12 is connected to the opening 13. The opening 13 provides a deformation buffer space for the deformation gap 12, preventing structural interference caused by the limited internal space when the sensor body deforms, and further ensuring the uniformity and elastic recovery of the deformation.

[0026] More specifically: There are two deformation gaps 12, which are located on both sides of the sensor body 1. The cross-section of the two deformation gaps 12 is in the shape of a broken line or a meandering shape, which extends the deformation path and optimizes the stress distribution, so that the sensor body 1 is divided into an I-shape. At the same time, this structure can make the sensor body generate uniform elastic deformation within the safe overload range of 200%FS. Combined with the elastic recovery capability of stainless steel, it can effectively improve the overload protection performance.

[0027] In other embodiments, the cross-section of the deformation gap 12 can also be a square shape, a wave shape, or a broken line shape.

[0028] In some embodiments, the connector 21 and the parameter storage module 22 are integrally formed. The outer side of the connector 21 is provided with a protective sleeve 23. The protective sleeve can prevent mechanical wear when the connector is plugged in and out. At the same time, it can buffer the impact of workshop vibration on the connector contact point and prevent signal interruption caused by vibration. The protective sleeve can also isolate workshop dust and oil stains and improve the environmental adaptability of the connector.

[0029] Specifically: The sensor body 1 is made of stainless steel. The height of the sensor body 1 is 17-22mm, preferably 19.10mm. The length of the sensor body 1 is 14-18mm, preferably 16mm. This size can fit the narrow installation space of the end effector of the 3C product assembly line and avoid interference with surrounding components.

[0030] Furthermore: the upper surface of the sensor body 1 is the force-bearing surface, the lower surface of the sensor body 1 is the placement surface, and a receiving space 14 is provided at the axis of the sensor body 1. The strain acquisition module 11 is located inside the receiving space 14. The flatness of the upper and lower surfaces of the sensor body is controlled to ≤0.02mm to ensure that the force value is transmitted evenly when subjected to force and there is no initial off-center load error.

[0031] Optionally: The parameter storage module 22 is a TEDS parameter storage module, the connector 21 is an aviation plug, and the fixed connection between the cable 3 and the strain acquisition module 11 is covered with epoxy resin. When the sensor is powered on or replaced, and the connector 21 is plugged into the external controller, the parameter storage module 22 will automatically transmit the stored sensitivity parameters to the external actuator controller. The controller, combined with the electrical signal output by the strain acquisition module 11, will directly calculate the accurate force value without the need for manual calibration with weights, thus completely eliminating the ±2%FS error of manual calibration. The force control accuracy deviation is stable at ±0.05%FS. Epoxy resin has excellent insulation, corrosion resistance, and vibration resistance, which can prevent signal interruption caused by loosening of the welding point due to workshop vibration. At the same time, it isolates the connection point from the corrosion of alcohol and solder fumes, further reducing the probability of sensor failure.

[0032] Specifically: The sensor body 1 has a flat rectangular shape and is made of stainless steel elastomer. The strain acquisition module 11 also includes a closed-loop signal processing module. The closed-loop signal processing module can perform linearization correction and temperature compensation on the acquired raw electrical signal to ensure the stability and accuracy of the output signal and provide a reliable electrical signal basis for subsequent force value calculation.

[0033] In some embodiments, the pins of the connector are for power, signal, and TEDS communication, respectively, so that the sensor body can operate normally and the data of the strain acquisition module can be transmitted.

[0034] The specific work process is as follows: The lower surface of the sensor body 1 is fixed to the end of the actuator with an M3 bolt. The connector 21 of the communication component 2 is connected to the female connector of the external controller. After connection, the strain acquisition module is started through the red and black pins of the connector. The parameter storage module 22 automatically uploads the sensitivity parameters to the external controller to complete the calibration-free start-up. When the workpiece to be measured contacts the force-bearing surface of the sensor body 1 and pressure is applied, the sensor body 1 generates uniform elastic deformation through the deformation gap 12. The strain acquisition module 11 converts the deformation into a raw electrical signal. After temperature compensation and linearization correction by the closed-loop signal processing module, it is transmitted to the parameter storage module 22 through the cable 3. The parameter storage module 22 matches the processed electrical signal with the pre-stored sensitivity parameters and converts it into an accurate force value signal. The signal is then transmitted to the external controller through the IO signal transmission pin of the connector 21. The external controller adjusts the actuator pressure in real time according to the target force value to realize closed-loop force control of contact pressing, ensuring that the workpiece has good contact without being damaged.

[0035] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A calibration-free miniature force sensor, characterized in that, The sensor includes a sensor body (1), one side of which is electrically connected to a communication component (2). The communication component (2) includes a connector (21) and a parameter storage module (22). The parameter storage module (22) is electrically connected to the sensor body (1) via a cable (3). The parameter storage module (22) stores specific sensitivity values.

2. The calibration-free miniature force sensor according to claim 1, characterized in that, The sensor body (1) is equipped with a strain acquisition module (11), which is electrically connected to the parameter storage module (22).

3. The calibration-free miniature force sensor according to claim 2, characterized in that, The end of the cable (3) away from the parameter storage module (22) passes through the sensor body (1) and is fixedly connected to one side of the strain acquisition module (11).

4. The calibration-free miniature force sensor according to claim 1, characterized in that, The sensor body (1) has a deformation gap (12) for deformation of the sensor body (1), and an opening (13) is provided on the sensor body (1). One end of the deformation gap (12) is connected to the opening (13).

5. The calibration-free miniature force sensor according to claim 4, characterized in that, There are two deformation gaps (12), which are located on both sides of the sensor body (1). The cross-sections of the two deformation gaps (12) are in the shape of a broken line or a meandering shape.

6. The calibration-free miniature force sensor according to claim 1, characterized in that, The connector (21) and the parameter storage module (22) are integrally formed, and a protective sleeve (23) is provided on the outside of the connector (21).

7. The calibration-free miniature force sensor according to claim 1, characterized in that, The sensor body (1) is made of stainless steel. The height of the sensor body (1) is 17-22mm and the length of the sensor body (1) is 14-18mm.

8. The calibration-free miniature force sensor according to claim 2, characterized in that, The upper surface of the sensor body (1) is the force-bearing surface, the lower surface of the sensor body (1) is the placement surface, and a receiving space (14) is provided at the axis of the sensor body (1). The strain acquisition module (11) is located inside the receiving space (14).

9. The calibration-free miniature force sensor according to claim 3, characterized in that, The parameter storage module (22) is a TEDS parameter storage module, the connector (21) is an aviation plug, and the fixed connection between the cable (3) and the strain acquisition module (11) is covered with epoxy resin.

10. The calibration-free miniature force sensor according to claim 2, characterized in that, The sensor body (1) has a flat rectangular shape and is made of stainless steel elastomer. The strain acquisition module (11) also includes a closed-loop signal processing module.

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