Torque sensor and testing machine therefor

Abstract

The present application relates to the technical field of torque detection, in particular to a kind of torque sensor and testing machine thereof, including test platform, sample, transfer frame, installation base and gripper disc, the transfer frame is installed in the middle part of test platform by sliding fit mode, and the upper portion of test platform is fixedly installed with transfer cylinder, and the telescopic end of transfer cylinder is fixedly connected with transfer frame, and the bottom of transfer frame is fixedly installed with installation base, and sample is fixedly placed in installation base, and sample is located directly below transfer frame, and the bottom of transfer frame is movably installed with gripper disc, and gripper disc is in contact with sample.The torque testing machine can detect the change of torque during bolt tightening or disassembly, solve the problem that traditional torque testing machine is difficult to simulate bolt actual assembly environment, clamping mode and stress state during testing bolt torque, and the problem of single test function and small applicable scene range.

Description

Technical Field

[0001] This invention relates to the field of torque detection technology, specifically a torque sensor and its testing machine. Background Technology

[0002] Bolted connections are widely used in machinery manufacturing, automotive assembly, rail transportation, aerospace, engineering machinery, and building structures, achieving reliable connections between components through threaded mating. The tightening torque of a bolt directly affects the preload, vibration resistance, and long-term reliability of the connection. Insufficient tightening torque can easily lead to loosening, seal failure, or structural vibration; excessive tightening torque can cause thread stripping, bolt yielding, deformation of the connected parts, or even breakage. Therefore, during bolt production, assembly, and maintenance, it is usually necessary to test the tightening torque, loosening torque, ultimate torque, and torque variations under different operating conditions to evaluate the fastening performance and reliability of the bolted connection. Existing torque testing equipment typically measures torque changes by clamping the bolt head or nut and driving its rotation.

[0003] However, traditional bolt torque testers have limited testing capabilities, typically measuring bolt torque only under standard clamping conditions at room temperature. They struggle to simulate the complex stress states of bolts in real-world environments. For example, bolts undergoing long-term service can be affected by temperature changes, vibration and impact, surface oil contamination, corrosion, varying clamping areas, and different tool contact patterns. These factors all alter the actual tightening or loosening difficulty of the bolt. Especially under high or low temperature conditions or thermal expansion and contraction, the thread fit between the bolt and nut changes; the stress area and stress pattern on the bolt head also differ under different operators or tools. Existing testing equipment struggles to effectively simulate these actual working conditions, resulting in discrepancies between test data and actual usage, and limiting its applicability. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a torque testing machine, thereby solving the problems of traditional torque testing machines in the bolt torque detection process, which are unable to simulate the actual use environment, tool contact method, and temperature change conditions of bolts, and have limited testing functions and applicable scenarios.

[0005] The technical solution adopted by the present invention to solve its technical problem is a torque testing machine, including a testing platform, a bolt sample, a transfer frame, a mounting base, and a gripper plate. The transfer frame is installed in the middle of the testing platform by a sliding fit. A transfer cylinder is fixedly installed on the upper part of the testing platform. The telescopic end of the transfer cylinder is fixedly connected to the transfer frame. A mounting base is fixedly installed on the bottom of the transfer frame. The bolt sample is fixedly placed in the mounting base and is located directly below the transfer frame. A gripper plate is movably installed on the bottom of the transfer frame and contacts the bolt head or nut part of the bolt sample.

[0006] A weight plate is movably mounted on the upper part of the mounting base. A pressure sensor is set at the bottom of the weight plate. An approach groove is opened circumferentially on the weight plate. The bolt sample is fixedly placed in the middle of the weight plate. Multiple torsion rollers are slidably mounted on the mounting base. The torsion rollers slide in cooperation with the approach groove, and the outer wall of the torsion rollers is in close contact with the rod, nut or outer wall of the connected part of the bolt sample to achieve stable positioning and clamping of the bolt sample.

[0007] The lower part of the transfer frame is rotatably mounted with an access shaft, and the upper part of the transfer frame is fixedly mounted with a torsion motor. The output shaft of the torsion motor is poweredly connected to the access shaft. The lower part of the access shaft has an inwardly recessed groove, and the upper part of the gripper disc is slidably mounted in the lower groove of the access shaft. The torsion motor drives the access shaft to rotate, thereby driving the gripper disc to perform a torque test on the tightening or loosening of the bolt sample.

[0008] A release spring connects the gripper disc to the access shaft, and magnetically coupled electromagnets are symmetrically arranged between the upper part of the gripper disc and the lower part of the access shaft. Through the cooperation of the electromagnets and the release spring, the stress state of the bolt under impact, vibration, or intermittent tool loading can be simulated during the test, making the test results closer to actual assembly and disassembly conditions.

[0009] The lower part of the gripper disc is equipped with multiple tangential rods along its tangential direction. A contact groove is formed in the middle of each tangential rod, and a contact plate is coupled and installed within the contact groove. The contact plate is made of a flexible material, and its inner surface is in contact with the bolt head or the outer wall of the nut. By changing the contact area between the contact plate and the bolt head or nut, the contact state of different sizes of wrenches, sockets, clamping tools, or manual operation can be simulated.

[0010] Ribs are evenly installed on the inner surface of the bonding sheet. Each rib has an arc-shaped protrusion, and a rib shaft is fixedly installed in the center of the protrusion. The ribs are elastic structures, while the rib shafts are rigid structures. The rib shafts are used to simulate the edge of a rigid tool or a force-bearing skeleton, while the ribs are used to simulate elastic pads, wear contact layers, or clamping contact surfaces under different friction conditions.

[0011] An inflation groove is provided on the inner side of the rib, and a scaling groove is opened in the middle of the movable end of the bonding piece. A resilient extrusion plate is installed at both the upper and lower ends of the scaling groove. A gap is reserved between the extrusion plate and the bonding piece, and an air bladder is installed in the gap. The air bladder is connected to the air groove on the inner side of the rib. By adjusting the air bladder pressure, the degree of expansion of the rib can be changed, thereby simulating the bolt torque test environment under different tool clamping forces, different surface friction states, and different wear levels.

[0012] A temperature control plate is rotatably mounted at the end of the tangent rod. A tension spring connects the temperature control plate to the tangent rod. Heating wires are evenly distributed on the inner surface of the temperature control plate. A temperature sensing plate that cooperates with the heating wires is disposed inside the bonding plate. A hook is fixedly disposed at the movable end of the temperature control plate. The hook is located below the bonding plate and contacts the bolt head, the bottom of the nut, or the surface of the connected part. By locally heating the bolt sample with the temperature control plate, the torque change of the bolt under high temperature conditions, hot assembly conditions, or thermal expansion and contraction conditions can be simulated.

[0013] In addition, the present invention also provides a torque sensor, which is installed vertically in the middle of the transfer frame. The two output ends of the torque sensor are fixedly connected to the upper end of the output shaft of the torsion motor and the access shaft, respectively, for real-time detection of torque changes of the bolt sample during tightening or loosening.

[0014] The beneficial effects of this invention are: (1) The present invention uses multiple torsion rollers to circumferentially clamp the bolt sample, nut or connected part, which can evenly distribute the clamping force. While ensuring positioning stability, it avoids excessive clamping force at a single point, which may cause deformation of the threaded part or increase the test error. Through the combination structure of the gripper plate and the access shaft, the impact, vibration or intermittent loading conditions can be simulated during the bolt torque test, making the test environment closer to the actual assembly and disassembly state.

[0015] (2) This invention utilizes the shape and contact area changes of the bonding sheet to simulate the contact state of the bolt head and nut outer wall under different wrenches, sockets, clamps or manual operation methods. Through the cooperation of the rib shaft and the rib strip, the combined effect of the contact edge of the rigid tool and the elastic friction layer can be simulated; through the expansion or contraction of the rib strip, the torque change under different clamping forces, different friction coefficients and different wear degrees can be simulated, thereby improving the richness and reliability of bolt torque test data.

[0016] (3) The present invention can control the temperature of bolt samples or nuts locally by combining temperature control sheet, heating wire and temperature sensing sheet, simulate the actual stress state of bolts under high temperature, low temperature, thermal expansion and contraction or hot assembly environment, shorten the test cycle under different temperature conditions and improve test efficiency.

[0017] (4) The present invention collects the torque change between the torsion motor and the access shaft in real time through a torque sensor, and can obtain continuous torque data during the bolt tightening, loosening, disassembly or ultimate failure process, providing data support for bolt connection reliability evaluation, assembly process optimization and failure analysis. Attached Figure Description

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

[0019] Figure 1 This is a schematic diagram of the overall connection structure of the present invention; Figure 2 for Figure 1 A side view diagram; Figure 3 This is a schematic diagram showing the placement of the sample and the torsion roller in this invention; Figure 4 for Figure 3 Enlarged diagram of point A in the diagram; Figure 5 for Figure 3 Enlarged diagram of point B in the diagram; Figure 6 This is a schematic diagram showing the positional relationship between the sample and the bonding sheet in this invention; Figure 7 for Figure 6 Enlarged diagram of point C in the diagram; Figure 8 This is a schematic diagram showing the positional relationship between the bonding sheet and the temperature control sheet in this invention; Figure 9 for Figure 8 Enlarged diagram of point D in the diagram; Figure 10 for Figure 8 Enlarged diagram of point E in the diagram.

[0020] In the picture: 1. Test platform; 2. Sample; 3. Transfer frame; 4. Placement base; 5. Gripper plate; 11. Transfer cylinder; 41. Weight plate; 42. Approach groove; 43. Torque roller; 6. Access shaft; 31. Torsion motor; 60. Dust removal pipe; 61. Separation spring; 62. Electromagnet; 7. Tangent rod; 71. Proximity groove; 8. Adhesion piece; 72. Stop rod; 73. Stop hole; 74. Stop shaft; 80. Temperature sensing plate; 81. Rib; 82. Rib shaft; 83. Scaling groove; 84. Extrusion plate; 85. Airbag; 75. Temperature control plate; 76. Tension spring; 77. Heating wire; 78. Gripper; 9. Torque sensor. Detailed Implementation

[0021] To make the technical means, creative features, objectives, and effects of this invention easier to understand, the following is a summary. The present invention will be further described in conjunction with specific embodiments.

[0022] Example 1: As Figures 1 to 3 ,as well as Figure 5 As shown, to achieve accurate measurement of bolt tightening or loosening torque, a preferred embodiment of the present invention proposes a torque testing machine, including a testing platform 1, a sample 2, a transfer frame 3, a mounting base 4, and a gripper plate 5. The transfer frame 3 is installed in the middle of the testing platform 1 by a sliding fit. A transfer cylinder 11 is fixedly installed on the upper part of the testing platform 1, and the telescopic end of the transfer cylinder 11 is fixedly connected to the transfer frame 3. The mounting base 4 is fixedly installed on the bottom of the transfer frame 3, and the sample 2 is fixedly placed in the mounting base 4. 2 is located directly below the transfer frame 3. A gripper plate 5 is movably installed at the bottom of the transfer frame 3. The gripper plate 5 contacts the sample 2. The sample 2 is a bolted connection. A carrier plate 41 is movably installed on the upper part of the mounting base 4. A pressure sensor is set at the bottom of the carrier plate 41. An approach groove 42 is opened circumferentially on the carrier plate 41. The sample 2 is fixedly placed in the middle of the carrier plate 41. Multiple torsion rollers 43 are slidably installed on the mounting base 4. The torsion rollers 43 slide in cooperation with the approach grooves 42 and the outer wall of the torsion rollers 43 is in close contact with the outer wall of the sample 2.

[0023] During operation, the sample 2 to be tested is placed on the bearing plate 41. The axial pressure or preload on the sample 2 is detected by the change in the pressure sensor value. By comparing this value with a standard value, it is determined whether the installation state of the sample 2 meets the testing requirements. Then, the torsion roller 43 is pressed against and locked to the outer wall of the sample 2, thus fixing the position of the sample 2. The multiple torsion rollers 43 evenly distribute the clamping force, providing a stable clamping effect while avoiding excessive force at a single location that could cause local deformation of the bolts, nuts, or connected parts. Next, the transfer cylinder 11 is activated, pushing the transfer frame 3 downwards, which in turn moves the gripper plate 5 downwards, allowing the gripper plate 5 to reach the bolt head or nut position of the sample 2 and clamp it. Finally, the transfer cylinder 11 is locked.

[0024] Furthermore, to keep sample 2 clean during testing and improve clamping stability, an access shaft 6 is rotatably mounted on the lower part of the transfer frame 3, and a torsion motor 31 is fixedly mounted on the upper part of the transfer frame 3. The output shaft of the torsion motor 31 is poweredly connected to the access shaft 6. The lower part of the access shaft 6 has an inwardly recessed groove. The upper part of the gripper disk 5 is slidably mounted in the lower groove of the access shaft 6. A separation spring 61 is connected between the gripper disk 5 and the access shaft 6. Magnetic electromagnets 62 are symmetrically arranged between the upper part of the gripper disk 5 and the lower part of the access shaft 6. A dust removal pipe 60 is circumferentially mounted on the lower part of the access shaft 6. The bottom of the dust removal pipe 60 is inclined, and the bottom of the dust removal pipe 60 has an air outlet facing the sample 2.

[0025] During operation, as the gripper disc 5 approaches the sample 2, airflow is introduced into the dust removal pipe 60. The airflow is obliquely ejected from the lower end of the dust removal pipe 60 and blown towards the bolt head, nut, or threaded connection area of ​​the sample 2. The airflow cleans the torque testing area of ​​the sample 2, thereby reducing the impact of oil, metal shavings, or dust on the clamping stability and testing accuracy. Furthermore, as the gripper disc 5 approaches the sample 2, the electromagnet 62 is deactivated. At this time, under the elastic support of the separation spring 61, a vertical expansion gap exists between the gripper disc 5 and the access shaft 6. This expansion gap does not affect the synchronous rotation of the gripper disc 5 with the access shaft 6. By reserving this expansion gap, the intermittent operation of the electromagnet 62 can overcome the elastic force of the separation spring 61 during subsequent torque testing, causing the gripper disc 5 to move vertically. During this movement, it creates an axial impact or vibration loading effect on the sample 2, thus simulating the impact and vibration conditions of bolts during actual assembly, disassembly, or service, making the testing environment of the torque testing machine more closely resemble actual usage conditions. Subsequently, after the clamping plate 5 clamps the sample 2, the torsion motor 31 is started to work, simulating the process of applying rotational torque to bolts and nuts by tightening or disassembling tools.

[0026] Example 2: In this example, to make the clamping operation of the torque testing machine more compatible with the contact state between different tools and bolts, multiple tangential rods 7 are installed on the lower part of the gripper disk 5 along its tangential direction. A contact groove 71 is opened in the middle of the tangential rod 7, and a contact piece 8 is coupled and installed in the contact groove 71. The contact piece 8 is made of a tough material, and the inner side of the contact piece 8 is in contact with the bolt head or the outer wall of the nut of the sample 2. A stop rod 72 is fixedly installed on the tangential rod 7 at the position where it is tangent to the gripper disk 5. Stop holes 73 are evenly opened on the stop rod 72, and a stop shaft 74 is coupled and installed in the stop hole 73. The lower part of the stop shaft 74 passes through the movable end of the contact piece 8. The fixed end and the movable end of the contact piece 8 maintain an arc-shaped bend, and the distance between the fixed end of the contact piece 8 and the axis of the gripper disk 5 is smaller than the distance between the movable end of the contact piece 8 and the axis of the gripper disk 5.

[0027] During operation, in actual use environments, the contact area and force distribution between different sizes of wrenches, sockets, clamps, or electric tightening tools and bolt heads and nuts vary. To ensure that the bolt torque test reflects both standard clamping conditions and adapts to testing requirements under different tool contact conditions, after the bottom of the gripper disc 5 is in contact with the bolt head or nut of sample 2, the fixed end of the contact piece 8 is first fixedly installed in the contact groove 71, making the fixed end of the contact piece 8 fit against the outer wall of sample 2. At this time, due to the difference in curvature or contact angle between the contact piece 8 and the outer wall of sample 2, there is an inclined angle between the movable end of the contact piece 8 and the outer wall of sample 2. Subsequently, according to different simulated tool clamping conditions, during the torsion test, the stop rod 72 is sequentially installed into the stop hole 73 at different positions. During the adjustment process, the degree of fit between the contact piece 8 and the outer wall of sample 2 increases or decreases accordingly, thereby simulating different tool contact areas, clamping angles, and force distribution positions, making the test results closer to the actual tightening or disassembly environment.

[0028] Furthermore, to further optimize the simulation of tool clamping state, surface friction state, and wear state, ribs 81 are evenly installed on the inner side of the bonding piece 8. Ribs 81 are provided with arc-shaped protrusions, and rib shafts 82 are fixedly installed in the middle of the protrusions. Ribs 81 are elastic structures, and rib shafts 82 are rigid structures. Ribs 81 wrap around rib shafts 82. An air groove is provided on the inner side of ribs 81. A scaling groove 83 is opened in the middle of the movable end of the bonding piece 8. Extrusion plates 84 made of tough material are installed at both the upper and lower ends of the scaling groove 83. A gap is reserved between the extrusion plates 84 and the bonding piece 8, and an air bladder 85 is installed in the gap. The air bladder 85 is connected to the air groove on the inner side of the rib 81. Two extrusion plates 84 pass through the middle of the stop shaft 74 in sequence. Bidirectional threads are symmetrically arranged in the middle of the stop shaft 74. Thread grooves that mesh with the bidirectional threads are provided in the two extrusion plates 84 respectively.

[0029] During operation, the contact state between the tool and the bolt head or nut during bolt tightening or loosening is affected by clamping force, coefficient of friction, tool wear, and bolt surface condition. To simulate these changes, after the bonding piece 8 is attached to the outer wall of the sample 2, multiple ribs 81 are attached to the bolt head or nut outer wall of the sample 2 one by one as the tilt angle of the bonding piece 8 changes. At this time, by rotating the stop shaft 74, the extrusion piece 84 is tilted and offset under the meshing action of the bidirectional thread, and the air bladder 85 is compressed during the offset process. The gas in the air bladder 85 is filled into the internal air groove of the rib 81 after being compressed, causing the rib 81 to expand. The rib shaft 82 set in the middle of the rib 81 can simulate the rigid tool contact edge or force-bearing skeleton, while the rib 81 can simulate the elastic contact layer, wear contact surface, or different friction pads. By expanding and contracting the ribs 81, bolt torque test conditions under different clamping forces, different friction states, and different tool wear states can be simulated, providing diverse clamping test methods for bolt torque determination and enriching test data.

[0030] Example 3: To simulate the torque change of a bolt caused by temperature changes in an actual service environment, a temperature control plate 75 is rotatably installed at the end of the tangent rod 7. A tension spring 76 is connected between the temperature control plate 75 and the tangent rod 7. Heating wires 77 are evenly arranged on the inner side of the temperature control plate 75. A temperature sensing plate 80 that cooperates with the heating wires 77 is arranged in the bonding plate 8. A hook 78 is fixedly provided at the movable end of the temperature control plate 75. The hook 78 is located below the bonding plate 8 and contacts the bottom of the bolt head, the bottom of the nut, or the surface of the connected part of the sample 2.

[0031] During operation, when bolted fasteners are used in environments with high or low temperatures or alternating temperature changes, the fit between the bolt, nut, and connected parts changes due to thermal expansion and contraction, thus affecting the tightening torque, loosening torque, or disassembly torque of the bolt. Therefore, during torque testing, the heating wire 77 can be activated according to the environmental variable detection requirements, thereby raising the temperature around the sample 2 and applying torque during this process to simulate torque changes under elevated temperature conditions. The temperature sensing plate 80 can absorb some heat to the bonding plate 8 and transfer it to the bolt head or nut position of the sample 2 through the ribs 81, simulating the thermal conductivity of metal bolts while shortening the heating time, thereby saving torque testing cycles and improving testing efficiency. In addition, under normal temperature or elevated temperature conditions, to simulate the axial pull-out force, preload changes, or vibration loads experienced by the bolt during assembly or disassembly, the temperature control plate 75 is rotated during torque testing, causing the claw 78 to abut against the bottom of the sample 2 or the surface of the connected parts. At this time, under the elastic force of the tension spring 76, sample 2 is subjected to torsional force, axial pulling force or limiting effect, which further enriches the loading method of sample 2 during torque test and improves the integrity of test data.

[0032] In addition, the present invention also provides a torque sensor, wherein the torque sensor 9 is installed vertically in the middle of the transfer frame 3, and the two output ends of the torque sensor 9 are fixedly connected to the output shaft of the torsion motor 31 and the upper end of the access shaft 6, respectively.

[0033] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A torque testing machine, comprising a testing platform (1), a sample (2), a transfer frame (3), a mounting base (4), and a gripper plate (5), wherein the transfer frame (3) is installed in the middle of the testing platform (1) by a sliding fit, a transfer cylinder (11) is fixedly installed on the upper part of the testing platform (1), the telescopic end of the transfer cylinder (11) is fixedly connected to the transfer frame (3), the mounting base (4) is fixedly installed on the bottom of the transfer frame (3), the sample (2) is fixedly placed in the mounting base (4), and the sample (2) is located directly below the transfer frame (3), and a gripper plate (5) is movably installed on the bottom of the transfer frame (3), the gripper plate contacting the bolt head or nut part of the bolt sample, characterized in that, A weight plate (41) is movably mounted on the upper part of the mounting base (4). A pressure sensor is set at the bottom of the weight plate (41). An approach groove (42) is opened on the circumferential direction of the weight plate (41). The sample (2) is fixedly placed in the middle of the weight plate (41). Multiple torsion rollers (43) are slidably mounted on the mounting base (4). The torsion rollers (43) slide in cooperation with the approach grooves (42) and the outer wall of the torsion rollers (43) is in close contact with the outer wall of the sample (2).

2. The torque testing machine according to claim 1, characterized in that: The lower part of the transfer frame (3) is rotatably mounted with an access shaft (6), and the upper part of the transfer frame (3) is fixedly mounted with a torsion motor (31). The output shaft of the torsion motor (31) is poweredly connected to the access shaft (6). The lower part of the access shaft (6) is provided with an inwardly recessed groove, and the upper part of the gripper disk (5) is slidably mounted in the lower groove of the access shaft (6).

3. A torque testing machine according to claim 2, characterized in that: A separation spring (61) is connected between the gripper disc (5) and the access shaft (6), and magnetically engaged electromagnets (62) are symmetrically arranged between the upper part of the gripper disc (5) and the lower part of the access shaft (6); and / or A dust removal pipe (60) is circumferentially installed on the lower part of the access shaft (6); and / or The bottom of the dust removal pipe (60) is inclined, and the bottom of the dust removal pipe (60) is provided with an air outlet facing the sample (2).

4. A torque testing machine according to claim 2, characterized in that: The lower part of the gripper disc (5) is equipped with multiple tangential rods (7) along its tangential direction. A proximity groove (71) is provided at the middle position of the tangential rod (7), and a bonding piece (8) is coupled and installed in the proximity groove (71); and / or The bonding piece (8) is made of a tough material, and the inner side of the bonding piece (8) is bonded to the bolt head or the outer wall of the nut.

5. A torque testing machine according to claim 4, characterized in that: A stop rod (72) is fixedly installed on the tangent rod (7) at the position where it is tangent to the claw plate (5). Stop holes (73) are evenly opened on the stop rod (72). A stop shaft (74) is coupled and installed in the stop hole (73), and the lower part of the stop shaft (74) passes through the movable end of the bonding piece (8).

6. A torque testing machine according to claim 4, characterized in that: The inner side of the bonding piece (8) is uniformly equipped with ribs (81), the ribs (81) are provided with arc-shaped protrusions, and a rib shaft (82) is fixedly installed in the middle of the protrusions. The ribs (81) are elastic structures, the rib shaft (82) is a rigid structure, and the ribs (81) are wrapped around the rib shaft (82).

7. A torque testing machine according to claim 6, characterized in that: An inflation groove is provided on the inner side of the rib (81), and a scaling groove (83) is provided in the middle of the movable end of the fitting piece (8). Both the upper and lower ends of the scaling groove (83) are equipped with extrusion pieces (84) made of tough material; and / or A gap is reserved between the extrusion sheet (84) and the bonding sheet (8), and an airbag (85) is installed in the gap. The airbag (85) is connected to the air groove on the inner side of the rib (81); and / or The middle part of the stop shaft (74) is connected to two extrusion plates (84) in sequence. The middle part of the stop shaft (74) is symmetrically provided with bidirectional threads, and the two extrusion plates (84) are respectively provided with thread grooves that mesh with the bidirectional threads.

8. A torque testing machine according to claim 5, characterized in that: The fixed end and the movable end of the bonding piece (8) are kept in an arc-shaped bend, and the distance between the fixed end of the bonding piece (8) and the axis of the gripper plate (5) is less than the distance between the movable end of the bonding piece (8) and the axis of the gripper plate (5).

9. A torque testing machine according to claim 4, characterized in that: A temperature control plate (75) is rotatably mounted on the end of the tangent rod (7). A tension spring (76) is connected between the temperature control plate (75) and the tangent rod (7). Heating wires (77) are evenly arranged on the inner side of the temperature control plate (75). A temperature sensing plate (80) that cooperates with the heating wires (77) is provided in the bonding plate (8). A hook (78) is fixedly provided at the movable end of the temperature control plate (75). The hook (78) is located below the bonding plate (8) and the hook (78) is in contact with the bolt head, the bottom of the nut or the surface of the connected part.

10. A torque sensor, applied to a torque testing machine according to any one of claims 2-9, characterized in that, A torque sensor (9) is vertically installed in the middle of the transfer frame (3). The two output ends of the torque sensor (9) are fixedly connected to the output shaft of the torsion motor (31) and the upper end of the access shaft (6), respectively.

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