Micro-torque detection device and calibration method thereof

Abstract

The present application relates to the field of precision torque measurement, and particularly relates to a micro-torque detection device and a calibration method thereof, comprising a support, a scale disc fixedly installed on the support, and a pointer arranged on the scale disc through a mounting base, the pointer is made of a high-elastic metal material, one end of the pointer is fixedly connected to the mounting base, and the other end of the pointer is provided with a stress mark, and an inner arc surface of the support is provided with a guide mechanism. Through the cooperation of multiple components in the guide mechanism, when the pointer is subjected to the force of micro-torque rotation, the pointer will be deformed, through the setting of the guide plate and the guide groove, the maximum deformation of the pointer can be limited while the pointer is guided, and through the bending of the pointer, the driving connecting rod drives the extrusion plate to move to extrude the air bag, the maximum bending angle of the pointer is limited based on the air bag, the elastic modulus of the pointer is selected to match the sensitivity coefficient of the strain gauge, so that the optimal signal-to-noise ratio and measurement accuracy are achieved.

Description

Technical Field

[0001] This invention relates to the field of precision torque measurement, and more specifically to a micro-torque detection device and its calibration method. Background Technology

[0002] Micro-torque measurement technology is one of the core technologies in high-end equipment fields such as precision manufacturing, inertial navigation, micro-motor drive and medical equipment. Currently, commonly used torque detection devices mainly include strain gauge, photoelectric and mechanical pointer types.

[0003] Most traditional strain gauge torque sensors typically mount strain gauges directly to a mounting base, indirectly calculating torque values ​​by measuring the torsional deformation of the shaft. While these sensors offer a wide measurement range, their minimum measurable torque is usually limited to 10. -2 The Nm range is difficult to meet the requirements of higher precision micro-torque measurement. In addition, they are susceptible to temperature drift and electromagnetic interference, and have a low signal-to-noise ratio in the micro-torque range. Photoelectric torque sensors utilize optical principles for non-contact measurement, offering advantages such as high resolution. However, they are subject to stringent environmental requirements, have complex systems, and are expensive. Mechanical pointer-scale torque measuring devices offer advantages such as simple structure, low cost, and intuitive readings, but they suffer from visual errors, and the mechanical pointer mechanism is prone to deformation and wear due to vibration, impact, or material fatigue.

[0004] There is an inherent contradiction between the measurement range and accuracy of traditional pointer torque meters. To ensure sufficient visual resolution, the pointer needs to have a large amount of elastic deformation, but this can lead to significant bending deformation and introduce obvious nonlinear errors. To solve this problem, pointer torque meters and photoelectric torque sensors are used in combination. However, in the process of detecting micro-torque, it is impossible to guide the pointer deformation. Limiting the maximum deformation of the pointer solely by the pointer material may cause the pointer to break or be damaged due to excessive deformation. This results in deviations in the torque detection results of the micro-torque detection device and affects the continuous detection of micro-torque.

[0005] Therefore, the present invention provides a micro-torque detection device and its calibration method to solve the above problems. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a micro-torque detection device and its calibration method.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: a micro-torque detection device, including a bracket, a scale fixedly installed on the bracket, and a pointer set on the scale via a mounting base. The pointer is made of a highly elastic metal material, one end of which is fixedly connected to the mounting base, and the other end is provided with a force mark. The inner arc surface of the bracket is provided with a guide mechanism, and the surface of the pointer is provided with an electrical signal detection mechanism. The guiding mechanism includes two symmetrically arranged guide plates, a guide groove, a connecting rod, a mounting plate, an airbag, and a squeezing plate. The two guide plates are disposed on the inner arc surface of the bracket. The guide groove is formed on the surface of the guide plate, and the pointer is slidably disposed inside the guide groove. The two ends of the connecting rod are fixedly connected to the pointer and the squeezing plate, respectively. The mounting plate is fixedly connected to the opposite sides of the two guide plates, and the squeezing plate is slidably disposed with the mounting plate. The airbag is fixedly disposed on one side of the mounting plate by a straight rod, and the airbag and the squeezing plate are on the same horizontal line. The squeezing plate is slidably disposed on the opposite sides of the two guide plates.

[0008] In a preferred embodiment, the guiding mechanism further includes a positioning component, a water collection box, a drain pipe, a drain trough, a collection box, and a connecting pipe disposed on one of the guide plates. The water collection box is fixedly disposed on one side of the mounting plate. The drain pipe is longitudinally disposed on one side of the water collection box, and both ends of the drain pipe are respectively connected to the water collection box and the drain trough. The drain trough is disposed on one side of the mounting plate. A water pump is disposed on the surface of the connecting pipe for transporting coolant from the collection box to the water collection box. A drive unit is disposed inside the water collection box.

[0009] In a preferred embodiment, the collection box is fixedly inserted into one side of the mounting plate, and the surface of the collection box is provided with a water inlet groove connected to the drainage groove. The two ends of the connecting pipe are fixedly connected to the collection box and the water collection box respectively, and communicate with both of them. The surface of the airbag is fixedly connected with a return pipe communicating with the water collection box, and a one-way valve is provided inside the return pipe.

[0010] In a preferred embodiment, the positioning component includes a mounting bracket rotatably mounted on the upper surface of one of the guide plates via a pin. The mounting bracket has two parallel elastic rods fixedly connected inside. One end of the two elastic rods is fixedly connected to a limit rod, and the surface of the pointer has a limit groove with the same diameter as the limit rod.

[0011] In a preferred embodiment, the electrical signal detection mechanism includes a strain gauge and a signal processing unit. The strain gauge is attached to the surface of the pointer and is connected to the signal processing unit via a signal lead, for converting the strain generated by the pointer bending under force into an electrical signal output.

[0012] In a preferred embodiment, the signal processing unit includes a signal conditioning circuit and a display module. The signal conditioning circuit is used to process the electrical signal output by the strain gauge, and the display module is used to display the torque measurement value in real time. The output end of the signal processing unit is also provided with a data communication interface for transmitting the measurement data to an external device.

[0013] A calibration method for a micro-torque detection device, applied to any one of the micro-torque detection devices described above, includes the following steps: S1: Securely fix the micro-torque detection device on a calibration platform and finely adjust its position so that the force mark at the end of the pointer is precisely aligned with the force point of a bridge-type weighing sensor, ensuring that the lever arm length is consistent with the actual measurement. S2: Slowly rotate or load the micro-torque detection device to make the pointer bend under force. After the reading stabilizes, synchronously read and record the reference force value measured by the bridge weighing sensor and the output signal value of the strain gauge signal after processing. During this process, the micro-deformation of the pointer is transmitted to the extrusion plate through the connecting rod, driving the extrusion plate to extrude the airbag, so that the guide mechanism completes the guidance, cooling and positioning of the pointer. S3: Calculate the currently applied standard torque value based on the reference force value and the known precise lever arm length; S4: Establish the correspondence between the standard torque value and the output signal value to form a calibration point; S5: Within the entire measurement range of the device, calibration point data at multiple different torque values ​​are obtained through progressive loading and unloading; S6: Perform statistical analysis and smoothing fitting on all calibration point data to generate a high-precision calibration curve for actual measurement.

[0014] Furthermore, the calibration process employs multiple cyclic loading and unloading methods to obtain repeatable data and calculate hysteresis errors. Appropriate mathematical methods are used for data fitting, and nonlinear errors can be compensated based on polynomial fitting or neural network algorithms, thereby further improving calibration accuracy.

[0015] The beneficial effects of this invention are as follows: Through the synergy of multiple components in the guiding mechanism, the pointer will deform when subjected to a micro-torque rotational force. By setting the guide plate and guide groove, the pointer can be guided while limiting the maximum deformation of the pointer. Furthermore, the bending of the pointer drives the connecting rod to move the compression plate and compress the airbag. Based on the limitation of the maximum bending angle of the pointer by the airbag, the elastic modulus of the pointer is matched with the sensitivity coefficient of the strain gauge to achieve the optimal signal-to-noise ratio and measurement accuracy. This avoids the pointer from breaking or being damaged due to excessive deformation, which would cause the micro-torque detection device to deviate from the torque detection results and affect the continuous detection of micro-torque. By combining a pointer and a strain gauge into a composite sensing structure, intuitive mechanical indication is combined with high-precision electrical signal measurement, effectively eliminating the error of purely visual readings. Furthermore, based on the high sensitivity characteristics of the strain gauge, this invention significantly expands the torque measurement range while ensuring linearity through optimized design of the pointer stiffness, further improving the measurement accuracy of micro-torque. Attached Figure Description

[0016] Figure 1 This is a front structural schematic diagram of a micro-torque detection device and its calibration method proposed in this invention; Figure 2 This is a side view of the micro-torque detection device and its calibration method proposed in this invention. Figure 3 This is a schematic diagram of the guide mechanism and dial structure of a micro-torque detection device and its calibration method proposed in this invention; Figure 4 This is a schematic diagram of the guide mechanism structure of a micro-torque detection device and its calibration method proposed in this invention; Figure 5 This is a schematic diagram of the mounting plate, extrusion plate, pointer, and collection box structure of a micro-torque detection device and its calibration method proposed in this invention. Figure 6 This is a schematic diagram of the positioning component and pointer structure of a micro-torque detection device and its calibration method proposed in this invention.

[0017] In the diagram: 1. Bracket; 2. Dial; 3. Mounting base; 4. Pointer; 5. Guide plate; 6. Guide groove; 7. Connecting rod; 8. Mounting plate; 9. Airbag; 10. Extrusion plate; 11. Water collection box; 12. Drain pipe; 13. Drainage trough; 14. Collection box; 15. Connecting pipe; 16. Return pipe; 17. Mounting bracket; 18. Elastic rod; 19. Limiting rod; 20. Limiting groove; 21. Strain gauge; 22. Signal processing unit; 23. Bridge-type load cell. Detailed Implementation

[0018] The present invention will now be further described with reference to the accompanying drawings.

[0019] Reference Figures 1-6 The present invention provides a micro-torque detection device, including a bracket 1, a scale 2 fixedly mounted on the bracket 1, and a pointer 4 set on the scale 2 via a mounting base 3. The pointer 4 is made of a highly elastic metal material, one end of which is fixedly connected to the mounting base 3, and the other end is provided with a force mark. The inner arc surface of the bracket 1 is provided with a guide mechanism, and the surface of the pointer 4 is provided with an electrical signal detection mechanism. The dial 2 has clear torque scale lines printed on its surface to provide a visual mechanical indication of the torque value; The pointer 4 is rotatably positioned at the center of the dial 2 via the mounting base 3; The deformation of pointer 4 is controlled within an appropriate range, with its maximum bending deformation not exceeding 3% of the effective length of pointer 4. Its elastic modulus is selected to match the sensitivity coefficient of strain gauge 21 to achieve optimal signal-to-noise ratio and measurement accuracy. The positioning assembly includes a mounting bracket 17 that is rotatably mounted on the upper surface of one of the guide plates 5 via a pin. The mounting bracket 17 has two parallel elastic rods 18 fixedly connected inside. One end of the two elastic rods 18 is fixedly connected to a limit rod 19, and the surface of the pointer 4 has a limit groove 20 with the same diameter as the limit rod 19. The mounting bracket 17 is used to install the elastic rod 18 and the limiting rod 19. The elastic rod 18 supports the limiting rod 19 while allowing the limiting rod 19 to move according to elastic deformation. The limiting rod 19 is used to insert into the limiting groove 20 to limit the position of the pointer 4. The limiting rod 19 is slidably set with the limiting groove 20. The limiting rod 19 can be retracted from the limiting groove 20 by the elastic rod 18 to avoid affecting the deformation of the pointer 4. Specifically, when the pointer 4 is installed on one side of the dial 2, the pointer 4 passes through the guide plate 5. After the pointer 4 is set in the guide groove 6, the limiting groove 20 moves with the pointer 4 and at the same time rotates the mounting bracket 17, so that it drives the limiting rod 19 to be perpendicular to the pointer 4. Thus, the limiting groove 20 and the limiting rod 19 are set parallel to each other. Through the elastic force of the elastic rod 18, the limiting rod 19 is inserted into the inside of the limiting groove 20 to limit the pointer 4, making the installation position of the pointer 4 more accurate. This makes the force mark set on the pointer 4 more precisely aligned with the force point of the bridge weighing sensor 23. When the pointer 4 deforms, the mounting bracket 17 is rotated to disengage the limiting rod 19 from the limiting groove 20, so as to avoid the limiting rod 19 affecting the deformation of the pointer 4. The electrical signal detection mechanism includes a strain gauge 21 and a signal processing unit 22. The strain gauge 21 is attached to the surface of the pointer 4 and is connected to the signal processing unit 22 through a signal lead. It is used to convert the strain generated by the bending of the pointer 4 into an electrical signal output. The strain gauge 21 is a temperature self-compensating foil resistance strain gauge, and it is precisely attached to the maximum strain area at the root of the pointer 4 along the axis of the pointer 4. Based on the high sensitivity of strain gauge 21, the design of the stiffness of pointer 4 is different from the traditional pointer 4 torque meter which requires a large deformation to facilitate visual reading. The pointer 4 in this device can be made to have greater stiffness, and its maximum bending deformation is controlled within 3% of the effective length of pointer 4. It reduces the nonlinear error and lever arm variation error caused by the bending of pointer 4, significantly expands the torque measurement range of the device, and improves the durability and long-term stability of pointer 4. According to the principles of mechanics of materials, under small deformation conditions, the strain of pointer 4... It satisfies the following relationship with the external force F: ; in, For strain, the final physical quantity measured directly determines the deflection of pointer 4; L is the lever arm length, which is the distance from the point of application of the force to the fixed end of pointer 4; F is the external force, which is converted from the torque to be measured through the lever arm L; E is the elastic modulus, which represents the stiffness of the material; b is the width of pointer 4; and h is the thickness of pointer 4. By reasonably selecting the material and geometric parameters of pointer 4, high-sensitivity measurement under small deformation conditions can be achieved. The high sensitivity of strain gauge 21 ensures that high-quality electrical signal output can still be obtained even under such small deformation; Based on the traditional pointer 4 structure, it is improved, inheriting its advantages of simple structure and low cost. At the same time, the performance is improved by adding strain gauge 21, avoiding the high cost and environmental sensitivity of complex optoelectronic systems. The signal processing unit 22 includes a signal conditioning circuit and a display module. The signal conditioning circuit is used to process the electrical signal output by the strain gauge 21, and the display module is used to display the torque measurement value in real time. The output end of the signal processing unit 22 is also provided with a data communication interface for transmitting the measurement data to external devices. The design of the signal processing unit 22 meets the reliability requirements of industrial field applications and adopts a circuit design scheme with strong adaptability and good stability. The pointer 4 part is more resistant to harsh environments, while the electrical signal processing part can effectively deal with interference through appropriate signal conditioning technology. The overall device is more environmentally robust than a pure optoelectronic system. The guiding mechanism includes two symmetrically arranged guide plates 5, guide grooves 6, connecting rods 7, mounting plates 8, airbags 9, and extrusion plates 10. The two guide plates 5 are arranged on the inner arc surface of the bracket 1. The guide grooves 6 are opened on the surface of the guide plates 5, and the pointer 4 is slidably arranged inside the guide grooves 6. The two ends of the connecting rod 7 are fixedly connected to the pointer 4 and the extrusion plates 10, respectively. The mounting plates 8 are fixedly connected to the opposite sides of the two guide plates 5, and the extrusion plates 10 are slidably arranged with the mounting plates 8. The airbag 9 is fixedly arranged on one side of the mounting plates 8 by a straight rod, and the airbag 9 and the extrusion plates 10 are on the same horizontal line. The extrusion plates 10 are slidably arranged on the opposite sides of the two guide plates 5. Among them, the guide plate 5 and the guide groove 6 are used to guide and limit the pointer 4; Among them, the connecting rod 7 is used to connect the extrusion plate 10 and the pointer 4; Among them, the mounting plate 8 is used to support the airbag 9; Among them, the extrusion plate 10 is used to extrude the airbag 9, causing it to deform; The guiding mechanism also includes a water collection box 11, a drain pipe 12, a drain trough 13, a collection box 14, and a connecting pipe 15, which are disposed on one of the guide plates 5. The water collection box 11 is fixedly disposed on one side of the mounting plate 8. The drain pipe 12 is longitudinally disposed on one side of the water collection box 11, and both ends of the drain pipe 12 are respectively connected to the water collection box 11 and the drain trough 13. The drain trough 13 is disposed on one side of the mounting plate 8, and a drive unit is disposed inside the water collection box 11. The drive unit includes a miniature electric push rod and a push plate that is slidably disposed in the water collection box 11, and the push plate is tightly fitted to the inner wall of the water collection box 11. The water collection box 11 is used to store coolant, and the surface of the water collection box 11 is provided with a water inlet pipe for adding coolant to the water collection box 11. The surface of the water inlet pipe is provided with a pressure relief valve to prevent air from continuously entering the water collection box 11 from the airbag 9, which would cause too much air inside the water collection box 11 and affect the delivery and recycling of coolant. The drain pipe 12 is used to transport coolant to the drain tank 13; The drain trough 13 is used to guide the coolant and to control the temperature of the pointer 4. The collection box 14 and the connecting pipe 15 are used to transport coolant, and the surface of the connecting pipe 15 is equipped with a water pump to transport the coolant in the collection box 14 to the water collection box 11. The collection box 14 is fixedly inserted into one side of the mounting plate 8, and the surface of the collection box 14 is provided with a water inlet groove connected to the drainage groove 13. The two ends of the connecting pipe 15 are fixedly connected to the collection box 14 and the water collection box 11 respectively, and are connected to both. The surface of the airbag 9 is fixedly connected with a return pipe 16 connected to the water collection box 11, and a one-way valve is provided inside the return pipe 16. Among them, the one-way valve is used to control the direction of airflow in the airbag 9, so that the air in the airbag 9 can only enter the water collection box 11 through the return pipe 16, while the coolant in the water collection box 11 cannot enter the airbag 9 through the return pipe 16, which affects the airbag 9. The return pipe 16 is used to transport the coolant transported by the connecting pipe 15 to the water collection box 11; Specifically, after the pointer 4 is precisely aligned with the bridge weighing sensor 23, when the pointer 4 is subjected to a micro-torque rotational force, the pointer 4 deforms, causing the force point and the force mark to press against each other. The pointer 4 deforms inside the guide groove 6, thereby causing the strain gauge 21 to deform synchronously and its resistance is detected. The electrical signal after resistance detection is transmitted to the signal processing unit 22, and the deformation range of the pointer 4 is displayed on the scale 2, thus completing the detection of micro-torque and realizing the composite structure of the pointer 4 and the strain gauge 21, eliminating visual errors and mechanical wear problems. Simultaneously, when pointer 4 deforms, the drive link 7 moves, which in turn drives the compression plate 10 to move, so that the compression plate 10 fits against the airbag 9 and compresses the airbag 9. Based on the maximum deformation of the airbag 9, the maximum bending angle of pointer 4 is limited. When the airbag 9 is compressed to the maximum deformation, pointer 4 cannot bend again, so that the elastic modulus of pointer 4 is matched with the sensitivity coefficient of strain gauge 21 to achieve the optimal signal-to-noise ratio and measurement accuracy. This avoids pointer 4 from breaking or being damaged due to excessive deformation, which would cause the torque detection device to deviate from the torque detection result and affect the continuous detection of the micro-torque. At the same time, after the airbag 9 is squeezed, the air inside it enters the water collection box 11 through the return pipe 16. At the same time, the micro electric push rod is activated to drive the push plate to move, providing sufficient driving force for the coolant. This allows the coolant in the water collection box 11 to enter the drain trough 13 through the drain pipe 12 and flow in the drain trough 13. The drain trough 13 guides the coolant, allowing it to flow inside the pointer 4 and cool the pointer 4. After the coolant finishes flowing in the drain tank 13, it enters the collection box 14 in the water tank. After the pointer 4 is reset, the connecting rod 7 is driven to reset and the water pump is started. The pump then transports the coolant in the collection box 14 to the water collection box 11 through the connecting pipe 15, realizing the recycling and reuse of the coolant. This avoids the coolant dissolving the adhesive on the strain gauge 21 and corroding the strain grid, while also preventing the waste of coolant.

[0020] A calibration method for a micro-torque detection device, applied to any of the micro-torque detection devices mentioned above, the method using a high-precision bridge weighing sensor 23 as a reference, includes the following steps: S1: Securely fix the micro-torque detection device on a calibration platform and finely adjust its position so that the force mark at the end of the pointer 4 is precisely aligned with the force point of the bridge-type weighing sensor 23, ensuring that the lever arm length is consistent with the actual measurement. S2: Slowly rotate or load the micro-torque detection device to make the pointer 4 bend under force. After the reading stabilizes, synchronously read and record the reference force value measured by the bridge weighing sensor 23 and the output signal value processed by the strain gauge 21. During this process, the micro-deformation of the pointer 4 is transmitted to the extrusion plate 10 through the connecting rod 7, driving the extrusion plate 10 to extrude the airbag 9, so that the guide mechanism completes the guidance and positioning of the pointer 4. S3: Calculate the current applied standard torque value based on the reference force value and the known precise lever arm length; S4: Establish the correspondence between the standard torque value and the output signal value to form a calibration point; S5: Within the entire measurement range of the device, calibration point data at multiple different torque values ​​are obtained through progressive loading and unloading; S6: Perform statistical analysis and smoothing fitting on all calibration point data to generate a high-precision calibration curve for actual measurement; The calibration process employs multiple cyclic loading and unloading methods to obtain repeatable data and calculate hysteresis errors. Appropriate mathematical methods are used for data fitting, and nonlinear errors can be compensated based on polynomial fitting or neural network algorithms to further improve calibration accuracy. After obtaining calibration point data at multiple different torque values ​​through step-by-step loading and unloading, the data is processed using an appropriate mathematical fitting method to generate an accurate calibration curve or calibration formula. The calibration relationship can be expressed as: ; Where T is the torque to be measured. The output signal is the original reading (voltage or digital signal) reflecting the magnitude of the torque. Its specific form is determined through calibration experiments and can be linear, polynomial, or other appropriate forms to accurately describe the correspondence between the torque and the output signal. The data processing uses the least squares method for linear fitting, and can compensate for nonlinear errors based on polynomial fitting or neural network algorithms to further improve calibration accuracy, thus ensuring both calibration accuracy and good engineering applicability. The provided dedicated calibration method is relatively simple to operate. By using a high-precision weighing sensor and a reasonable calibration process, it effectively solves the problem of micro-torque calibration, ensuring the accurate traceability of the measurement value and the long-term measurement stability of the device. Meanwhile, this application retains pointer 4 and dial 2 for quick and intuitive on-site judgment, and also provides electrical signal output for remote monitoring, data recording and automated control, thus meeting the diversified needs of modern industrial measurement and control. Furthermore, the entire calibration process can be automated by directly connecting the output signal of the weighing sensor to the signal processing unit 22, and controlling the synchronous acquisition, recording and processing of data by the built-in program, which greatly improves calibration efficiency and consistency.

Claims

1. A micro-torque detection device, comprising a bracket (1), a dial (2) fixedly mounted on the bracket (1), and a pointer (4) mounted on the dial (2) via a mounting base (3), wherein the pointer (4) is made of a highly elastic metal material, one end of which is fixedly connected to the mounting base (3), and the other end is provided with a force marking, characterized in that, The inner arc surface of the bracket (1) is provided with a guide mechanism, and the surface of the pointer (4) is provided with an electrical signal detection mechanism; The guiding mechanism includes two symmetrically arranged guide plates (5), a guide groove (6), a connecting rod (7), a mounting plate (8), an airbag (9), and a squeezing plate (10). The two guide plates (5) are arranged on the inner arc surface of the bracket (1). The guide groove (6) is opened on the surface of the guide plate (5), and the pointer (4) is slidably arranged inside the guide groove (6). The two ends of the connecting rod (7) are fixedly connected to the pointer (4) and the squeezing plate (10) respectively. The mounting plate (8) is fixedly connected to the opposite side of the two guide plates (5), and the squeezing plate (10) is slidably arranged with the mounting plate (8). The airbag (9) is fixedly arranged on one side of the mounting plate (8) by a straight rod, and the airbag (9) and the squeezing plate (10) are on the same horizontal line. The squeezing plate (10) is slidably arranged on the opposite side of the two guide plates (5).

2. The micro-torque detection device according to claim 1, characterized in that, The guiding mechanism also includes a positioning component, a water collection box (11), a drain pipe (12), a drain trough (13), a collection box (14), and a connecting pipe (15) disposed on one of the guide plates (5). The water collection box (11) is fixedly disposed on one side of the mounting plate (8). The drain pipe (12) is longitudinally disposed on one side of the water collection box (11), and both ends of the drain pipe (12) are connected to the water collection box (11) and the drain trough (13) respectively. The drain trough (13) is disposed on one side of the mounting plate (8), and a driving unit is disposed inside the water collection box (11).

3. The micro-torque detection device according to claim 2, characterized in that, The collection box (14) is fixedly inserted into one side of the mounting plate (8), and the surface of the collection box (14) is provided with a water inlet groove connected to the drainage groove (13). The two ends of the connecting pipe (15) are fixedly connected to the collection box (14) and the water collection box (11) respectively, and communicate with both of them. The surface of the airbag (9) is fixedly connected with a return pipe (16) communicating with the water collection box (11), and a one-way valve is provided inside the return pipe (16).

4. The micro-torque detection device according to claim 2, characterized in that, The positioning component includes a mounting bracket (17) that is rotatably mounted on the upper surface of one of the guide plates (5) via a pin. The mounting bracket (17) has two parallel elastic rods (18) fixedly connected inside. One end of the two elastic rods (18) is fixedly connected to a limit rod (19), and the surface of the pointer (4) has a limit groove (20) with the same diameter as the limit rod (19).

5. The micro-torque detection device according to claim 1, characterized in that, The electrical signal detection mechanism includes a strain gauge (21) and a signal processing unit (22). The strain gauge (21) is attached to the surface of the pointer (4). The strain gauge (21) is connected to the signal processing unit (22) through a signal lead and is used to convert the strain generated by the bending of the pointer (4) into an electrical signal output.

6. A micro-torque detection device according to claim 5, characterized in that, The signal processing unit (22) includes a signal conditioning circuit and a display module. The signal conditioning circuit is used to process the electrical signal output by the strain gauge (21). The display module is used to display the torque measurement value in real time. The output end of the signal processing unit (22) is also provided with a data communication interface for transmitting the measurement data to an external device.

7. A calibration method for a micro-torque detection device, applied to a micro-torque detection device as described in any one of claims 1-6, characterized in that, Includes the following steps: S1: Secure the micro-torque detection device to a calibration platform and finely adjust its position so that the force mark at the end of the pointer (4) is precisely aligned with the force point of a bridge weighing sensor (23) to ensure that the lever arm length is consistent with the actual measurement. S2: Slowly rotate or load the micro-torque detection device to make the pointer (4) bend under force. After the reading stabilizes, synchronously read and record the reference force value measured by the bridge weighing sensor (23) and the output signal value after processing of the strain gauge (21) signal. During this process, the micro-deformation of the pointer (4) is transmitted to the extrusion plate (10) through the connecting rod (7), driving the extrusion plate (10) to extrude the airbag (9), so that the guide mechanism completes the guidance, cooling and positioning of the pointer (4). S3: Calculate the currently applied standard torque value based on the reference force value and the known precise lever arm length; S4: Establish the correspondence between the standard torque value and the output signal value to form a calibration point; S5: Within the entire measurement range of the device, calibration point data at multiple different torque values ​​are obtained through progressive loading and unloading; S6: Perform statistical analysis and smoothing fitting on all calibration point data to generate a high-precision calibration curve for actual measurement.

8. The calibration method for a micro-torque detection device according to claim 7, characterized in that, The calibration process employs multiple cyclic loading and unloading methods to obtain repeatable data and calculate hysteresis errors. Appropriate mathematical methods are used for data fitting, and nonlinear errors can be compensated based on polynomial fitting or neural network algorithms to further improve calibration accuracy.

Images