A foil resistance strain gauge for a torque sensor

Abstract

The utility model relates to foil resistance strain gauge technical field, and disclose a kind of foil resistance strain gauge for torque sensor, including strain gauge and fixed assembly, strain gauge includes substrate, sensitive grid and cover layer, substrate, sensitive grid and cover layer are fixedly connected two by two, the substrate is equipped with positioning slot, the substrate slidingly connected has ring array, the ring array both ends abutment has stop lever, the stop lever is equipped on fixed assembly, the ring array is by multiple parallel rings, each ring can only be circumferentially slid along the axis to be measured. The utility model is through the synergies of rigid ring array and stop lever, effectively suppresses the interference of axial deformation to sensitive grid resistance value, ensures that resistance change only by the circumferential deformation caused by transmission torque, fundamentally reduces measurement error.

Description

Technical Field

[0001] This utility model relates to the field of foil resistance strain gauge technology, specifically a foil resistance strain gauge for use in torque sensors. Background Technology

[0002] Foil resistance strain gauges are widely used as sensing elements in torque sensors. In traditional strain-type torque sensors, the elastic shaft with the strain gauge sensing grid attached should theoretically generate shear stress proportional to the torque when subjected to torque, thereby causing circumferential deformation of the sensing grid and reflecting the torque value through the change in resistance.

[0003] However, in actual operating conditions, the elastic shaft inevitably bears axial forces from the connected equipment (such as installation preload, thrust caused by thermal expansion, etc.). These axial forces cause axial deformation of the elastic shaft, which is directly transmitted to the strain gauge substrate and the sensing grid. Existing strain gauges are usually directly fixed to the substrate, lacking an effective isolation mechanism for deformation in directions other than the measurement direction. Therefore, the sensing grid responds to axial deformation, causing an unexpected change in its resistance value that is unrelated to torque. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a foil resistance strain gauge for torque sensors, which aims to solve the above-mentioned technical problems.

[0005] This utility model relates to a foil resistance strain gauge for a torque sensor. The foil resistance strain gauge for a torque sensor includes a strain gauge and a fixing assembly. The strain gauge is connected to the fixing assembly, and the fixing assembly is used to fix the strain gauge to the shaft to be measured. The strain gauge includes a substrate, a sensitive grid, and a cover layer. The substrate, the sensitive grid, and the cover layer are fixedly connected in pairs. The substrate is slidably connected to a ring array. The two ends of the ring array abut against a stop bar. The stop bar is connected to a fixing component. The ring array consists of multiple parallel rings, and each ring can only slide circumferentially along the axis to be measured.

[0006] Optionally, the fixing assembly includes a first fixing frame and a second fixing frame. The first fixing frame is slidably connected to one end of a top plate, and the other end of the top plate is slidably connected to the second fixing frame. The top plate is fixedly connected to one end of a spring, and the other end of the spring is fixedly connected to a lifting plate. The lifting plate is fixedly connected to a rack, and the rack meshes with a first gear. A rotating shaft is fixedly connected to the axis of the first gear, and the rotating shaft is rotatably connected to the first fixing frame. The rotating shaft is fixedly connected to a second gear, and the second gear meshes with a third gear. A hand-tightening rotating shaft is fixedly connected to the axis of the third gear, and the hand-tightening rotating shaft is rotatably connected to the first fixing frame.

[0007] Optionally, the first fixed frame is fixedly connected to a rotating frame, and the rotating frame is rotatably connected to a rotating shaft.

[0008] Optionally, the base is provided with a positioning groove.

[0009] Optionally, the substrate includes a flexible sealant layer, an insulating film is fixedly connected to the flexible sealant layer, and an anti-corrosion coating is fixedly connected to the insulating film.

[0010] This utility model has the following beneficial effects: (1) By setting up a ring array, this utility model reduces the axial deformation of the strain gauge without changing the torque on the shaft to be measured, thereby improving the response accuracy of the strain gauge.

[0011] (2) This utility model drives the rack to move by the meshing transmission of the hand-twisted shaft, the third gear, the second gear and the first gear. With the cooperation of the lifting plate and the spring, the top plate can be locked smoothly. The elastic shaft and the strain gauge can be fixed without complicated tools. The operation is convenient and efficient.

[0012] Of course, any product implementing this utility model does not necessarily need to achieve all of the above advantages at the same time. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments 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.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram showing the positional relationship between the present invention and the axis to be measured; Figure 3 This is a schematic diagram of the strain gauge part of the present invention; Figure 4 This is a schematic diagram of the fixing component of this utility model; Figure 5 This is a schematic diagram of the fixing component of this utility model; Figure 6 This is a schematic diagram of the base structure of this utility model; The attached diagram lists the components represented by each number as follows: In the diagram: 1. Strain gauge; 11. Substrate; 12. Sensing grid; 13. Covering layer; 14. Positioning groove; 15. Ring array; 16. Stop bar; 2. Fixing assembly; 21. First fixing frame; 22. Second fixing frame; 23. Top plate; 24. Spring; 25. Lifting plate; 26. Gear rack; 27. First gear; 28. Rotating shaft; 29. ​​Second gear; 210. Third gear; 211. Hand-tightening rotating shaft; 212. Rotating frame; 3. Flexible sealing layer; 4. High-strength insulating film; 5. Anti-corrosion coating. Detailed Implementation

[0015] 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.

[0016] Please see Figures 1-6 As shown, this utility model is a foil resistance strain gauge for torque sensors, including a strain gauge 1 and a fixing component 2. The strain gauge 1 is connected to the fixing component 2, and the fixing component 2 is used to fix the strain gauge 1 to the shaft to be measured. The strain gauge 1 includes a base 11, a sensing grid 12, and a cover layer 13. The base 11, the sensing grid 12, and the cover layer 12 are fixedly connected in pairs. The base 11 is slidably connected to a ring array 15. The two ends of the ring array 15 are abutted by a stop bar 16. The stop bar 16 is connected to the fixing component 2. The ring array 15 is composed of multiple parallel rings, and each ring can only slide circumferentially along the axis to be measured.

[0017] Through the aforementioned device, the transmission component of the torque sensor transmits torque to the shaft under test. The elastic deformation of the shaft causes the sensitive grid 12 in strain gauge 1 to deform, and the resistance of the sensitive grid 12 changes accordingly. The sensitive grid 12 of strain gauge 1 is connected to a Wheatstone bridge circuit. When there is no torque, the bridge is in a balanced state, and the output voltage is zero. When the resistance of the sensitive grid 12 changes due to torque, the bridge balance is broken, and a weak voltage signal, typically in the millivolt range, proportional to the change in the resistance of the sensitive grid 12, is output, realizing the conversion of the resistance signal into a voltage signal. The amplified and filtered voltage signal is transmitted to the data processing unit. The data processing unit, in conjunction with the pre-calibrated calibration coefficients of the sensor, calculates the actual torque value applied by the external device using a formula.

[0018] For ease of understanding, in the following description, circumferential deformation refers to the deformation of strain gauge 1 along the circumference of the bottom surface of the shaft under test; axial deformation refers to the deformation of strain gauge 1 along the axis of the shaft under test; outward axial deformation refers to the tensile deformation of strain gauge 1 along the axial direction of the shaft under test; and inward axial deformation refers to the compressive deformation of strain gauge 1 along the axial direction of the shaft under test. The ring array 15 is composed of multiple parallel rigid rings, each of which is slidably connected to the base 11. When strain gauge 1 tends to undergo axial deformation, the base 11 will cause each rigid ring of the ring array 15 to tend to move axially. Specifically, when strain gauge 1 tends to undergo inward axial deformation, the rigid rings of the ring array 15 will be obstructed by mutual compression, preventing strain gauge 1 from undergoing inward axial deformation. When strain gauge 1 tends to undergo outward axial deformation, the ring array 15 is blocked by the stop bar 16, preventing strain gauge 1 from undergoing outward axial deformation. When strain gauge 1 undergoes circumferential deformation, the base 11 slides relative to each ring of the ring array 15, thereby allowing strain gauge 1 to generate circumferential deformation. In this way, axial deformation of strain gauge 1 is blocked, while circumferential deformation is allowed, reducing the impact of axial deformation on the accuracy of torque measurement. To facilitate deformation and adapt to the shape of the ring array 15, both the base 11 and the cover layer 13 of strain gauge 1 are made of soft materials.

[0019] Optionally, the fixing component 2 includes a first fixing frame 21 and a second fixing frame 22. The first fixing frame 21 is slidably connected to one end of a top plate 23, and the other end of the top plate 23 is slidably connected to the second fixing frame 22. The top plate 23 is fixedly connected to one end of a spring 24, and the other end of the spring 24 is fixedly connected to a lifting plate 25. The lifting plate 25 is threadedly connected to a threaded rod 26, and the threaded rod 26 is threadedly connected to a first gear 27. A rotating shaft 28 is fixedly connected to the axis of the first gear 27, and the rotating shaft 28 is rotatably connected to the first fixing frame 21. The rotating shaft 28 is fixedly connected to a second gear 29, and the second gear 29 is meshed with a third gear 210. A hand-tightening rotating shaft 211 is fixedly connected to the axis of the third gear 210, and the hand-tightening rotating shaft 211 is rotatably connected to the first fixing frame 21.

[0020] Using the aforementioned device, one side of the base 11 of strain gauge 1 is placed against the top plate 23, and glue is applied to the side of strain gauge 1 that needs to be in contact with the shaft to be measured. The strain gauge 1 is then inserted into the shaft via the fixing assembly 2. Turning the hand-cranked shaft 211 controls the rotation of the third gear 210, which in turn controls the second gear 29 to rotate the shaft 28. The first gear 27 on the shaft 28 meshes with the worm gear of the threaded rod 26. The shaft 28 drives the first gear 27 to rotate, and the threaded rod 26 is controlled to move up and down, thereby moving the lifting plate 25 upwards. The spring 24 is compressed, lifting the top plate 23 upwards, allowing the strain gauge 1 to adhere tightly to the shaft to be measured. Afterwards, the hand-cranked shaft 211 is released, and the top plate 23 gradually descends under gravity, no longer tightly contacting the strain gauge 1, preventing the tight contact from affecting the sensitivity of the strain gauge 1 during deformation. Furthermore, this method of indirectly lifting the top plate 23 using the spring 24 avoids damage to the strain gauge 1 and the shaft to be measured due to excessive lifting force.

[0021] Optionally, the first fixed frame 21 is fixedly connected to a rotating frame 212, and the rotating frame 212 is rotatably connected to the rotating shaft 28.

[0022] The rotating frame 212 is used to support the rotating shaft 28 and prevent the rotating shaft 28 from breaking due to uneven stress.

[0023] Optionally, the base 11 has a positioning groove 14.

[0024] The positioning groove 14 is used to position the base 11 and the cover layer 13 to facilitate the assembly of the strain gauge 1.

[0025] Optionally, the substrate 11 includes a flexible sealant layer 3, the flexible sealant layer 3 is fixedly connected to an insulating film 4, and the insulating film 4 is fixedly connected to an anti-corrosion coating 5.

[0026] The preferred embodiments of this utility model disclosed above are merely illustrative of the present utility model. These preferred embodiments do not exhaustively describe all details, nor do they limit the utility model to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this utility model, thereby enabling those skilled in the art to better understand and utilize it. This utility model is limited only by the claims and their full scope and equivalents.

Claims

1. A foil resistance strain gauge for use in torque sensors, characterized in that, It includes a strain gauge (1) and a fixing component (2), wherein the strain gauge (1) is connected to the fixing component (2), and the fixing component (2) is used to fix the strain gauge (1) to the shaft to be measured; The strain gauge (1) includes a base (11), a sensing grid (12), and a cover layer (13). The base (11), the sensing grid (12), and the cover layer (13) are fixedly connected in pairs. The base (11) is slidably connected to a ring array (15). The two ends of the ring array (15) are abutted by a stop bar (16). The stop bar (16) is connected to a fixing component (2). The ring array (15) is composed of multiple parallel rings, and each ring can only slide circumferentially along the axis to be measured.

2. A foil resistance strain gauge for a torque sensor according to claim 1, characterized in that: The fixing component (2) includes a first fixing frame (21) and a second fixing frame (22). The first fixing frame (21) is slidably connected to one end of a top plate (23). The other end of the top plate (23) is slidably connected to the second fixing frame (22). The top plate (23) is fixedly connected to one end of a spring (24). The other end of the spring (24) is fixedly connected to a lifting plate (25). The lifting plate (25) is fixedly connected to a rack (26). The rack (26) is meshed with a first gear (27). A rotating shaft (28) is fixedly connected at the center of the first gear (27). The rotating shaft (28) is rotatably connected to the first fixing frame (21). The rotating shaft (28) is fixedly connected to a second gear (29). The second gear (29) is meshed with a third gear (210). A hand-tightening rotating shaft (211) is fixedly connected at the center of the third gear (210). The hand-tightening rotating shaft (211) is rotatably connected to the first fixing frame (21).

3. A foil resistance strain gauge for a torque sensor according to claim 2, characterized in that: The first fixed frame (21) is fixedly connected to a rotating frame (212), and the rotating frame (212) is rotatably connected to the rotating shaft (28).

4. A foil resistance strain gauge for a torque sensor according to claim 1, characterized in that: The base (11) has a positioning groove (14).

5. A foil resistance strain gauge for a torque sensor according to claim 1, characterized in that: The substrate (11) includes a flexible sealant layer (3), the flexible sealant layer (3) is fixedly connected to an insulating film (4), and the insulating film (4) is fixedly connected to an anti-corrosion coating (5).

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