A retaining force probe fatigue testing device and detection method

Abstract

The application discloses a kind of holding force probe fatigue testing device and detection method, belong to fatigue testing technical field.The process of simulating holding force detection is realized by cam reciprocating motion, process: cam drives probe rapid feed, and makes probe reach required holding force with test block contact;Far rest end: cam rotation, probe is still in contact with test block and keeps static at this time, holding force size is unchanged;Return stroke: probe separates from test block under the action of return spring, probe keeps falling to zero;Near rest end: cam rotation, probe does not move and holding force is constant zero.

Description

Technical Field

[0001] This invention relates to the field of fatigue testing technology, and in particular to a fatigue testing device and testing method for a holding force probe. Background Technology

[0002] Aviation electrical connectors are widely used interconnecting devices in aerospace systems engineering. They enable the rapid connection and disconnection of wires and cables, playing a crucial role in the transmission of electrical power and signals in control systems. Their quality and reliability are critical to the success or failure of the entire aerospace project. During equipment operation, a significant proportion of equipment failures are caused by command transmission problems due to insufficient contact holding force leading to connector pin retraction or withdrawal. To ensure good conductivity during aviation electrical connector mating, it is essential to perform holding force testing on the connectors to guarantee mating reliability.

[0003] Currently, the retention force test of electrical connector contacts is generally performed using a mechanical spring pointer test tool. The testing process is as follows: the tester holds the test tool with the probe facing the contact and applies pressure to the contact by pressing the tool until the end of the slider is aligned with the pressure indicator line. If the contact does not retract during the application of force, the retention force is qualified; otherwise, the contact retention force is unqualified.

[0004] Chinese invention patent CN106568536A, "A Connector Retention Force Testing Device," discloses a connector retention force testing device, including a mating assembly, a testing assembly, a mounting platform, a testing spring, a retainer, and a floating connector. By setting the mating assembly and testing assembly on the mounting platform, the elastic force generated by the deformation of the testing spring is compared with the connector's retention force to determine whether the connector's retention force is qualified. Chinese invention patent CN 113358256A, "An Automatic Detection Device and Method for Crimping Contact Retention Force," discloses a retention force detection module, including a connector base, a pressure sensor, a pressure block, a mating rod, a pressure head, a testing head, a plug, and a spring. Pressure is generated by the testing head pressing the contact, and the pressure is transmitted to the pressure sensor via the pressure head and spring, allowing for real-time feedback of the applied force. However, after prolonged and repetitive retention force testing, the test spring in the above-mentioned retention force testing devices may experience fatigue fracture, plastic deformation, or other failure modes. This will lead to abnormalities in the connector's retention force detection, and the detection result will deviate from the actual retention force. If the test result is greater than the actual holding force, pin retraction or retraction may occur; if the test result is less than the actual holding force, the contact portion of the contact body will wear and deform, leading to contact failure over long-term operation. Therefore, the long-term reliability of the holding force testing device is a key factor in ensuring good conductivity of the electrical connector.

[0005] To ensure the long-term reliability of the holding force probe testing device and avoid abnormal electrical connector continuity, a holding force probe fatigue testing device is invented to accelerate holding force fatigue testing and improve the working reliability of the holding force testing device. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and to develop a fatigue testing device and method for a holding force probe. A cam is used to achieve reciprocating motion, simulating the holding force testing process. The process is as follows: The cam drives the probe to feed rapidly, contacting the test block and achieving the required holding force. At the far end: the cam rotates, while the probe remains in contact with the test block and stationary, with the holding force remaining constant. At the return stroke: the probe separates from the test block under the action of a return spring, and the holding force drops to zero. At the near end: the cam rotates, the probe remains stationary, and the holding force is always zero.

[0007] The technical solution of the present invention: A fatigue testing device for holding force probe, the fatigue testing device includes a load-bearing frame module 1, a motion control module 2, a force transmission module 3, and a distance adjustment module 4; The top of the load-bearing frame module 1 is respectively equipped with the motion part of the motion control module 2 and the distance adjustment module 4, and the control part of the motion control module 2 is installed inside the load-bearing frame module 1; The motion control module 2 includes a motion part and a control part. The motion part includes a perforated coupling 2-3, a fixing mechanism 2-4, and a microcontroller 2-6. The control part includes a stepper motor driver 2-1, a stepper motor 2-2, a power supply 2-5, and an analog-to-digital converter 2-7. The stepper motor driver 2-1 is connected to the stepper motor 2-2. The stepper motor 2-2 is connected to the perforated coupling 2-3. The fixing mechanism 2-4 and the microcontroller 2-6 are mounted on the top of the load-bearing frame module 1. The fixing mechanism 2-4 is used to drive the perforated coupling 2-3 and connects the perforated coupling 2-3 via a lead screw d. The motion of 3 is transmitted to cam 3-1; microcontroller 2-6 controls stepper motor driver 2-1 to provide power to stepper motor 2-2, which is used to drive force transmission module 3; analog-to-digital converter 2-7 is used to convert the analog signal of pressure sensor 3-6 into a digital signal; power supply 2-5 provides voltage to stepper motor driver 2-1, stepper motor 2-2, microcontroller 2-6 and analog-to-digital converter 2-7; fixing mechanism 2-4 includes frame and lead screw d, the frame is fixed to the top of load-bearing frame module 1 to support lead screw d and make the axis of lead screw d perpendicular to the plane of load-bearing frame module 1; The force transmission module 3 includes a cam 3-1, a polyurethane bearing 3-2, a bearing mounting base 3-3, a pressure sensor mounting plate 3-4, a pressure sensor base 3-5, a pressure sensor 3-6, a sleeve 3-7, an anti-rotation screw and a set screw 3-8, a spring guide shaft 3-9, a spring 3-10, a return spring 3-11, a force transmission rod 3-12, and a pin 3-13. The cam 3-1 adopts a sinusoidal modified curve. The axial direction of the cam 3-1 is connected to the lead screw d of the motion control module 2 via a key. The rotation of the plum blossom coupling 2-3 can drive the cam 3-1 to rotate. The circumferential direction of the cam 3-1 is... Polyurethane bearing 3-2 is in contact; polyurethane bearing 3-2 is installed at one end of bearing mounting base 3-3; the other end of bearing mounting base 3-3 is connected to one side of pressure sensor mounting plate 3-4, the middle of the other side of pressure sensor mounting plate 3-4 is fixed to one end of pressure sensor 3-6, and the periphery is connected to pressure sensor seat 3-5; pressure sensor seat 3-5 is cylindrical, and the inner diameter of the cylinder is divided into two sections, the section closer to pressure sensor mounting plate 3-4 has a larger diameter, and the section farther from pressure sensor mounting plate 3-4 has a smaller diameter. Pressure sensor 3-6 is located in the section with the larger diameter, and pressure sensor 3-6 is in contact with pressure sensor mounting plate 3-4. A sleeve 3-7 is fixed between the cylinder walls of sensor base 3-5; the other end of pressure sensor 3-6 is connected to one end of spring guide shaft 3-9, and pressure sensor 3-6 is also electrically connected to analog-to-digital converter 2-7; one end of force transmission rod 3-12 is a T-shape with an end slot, spring 3-10 is located in the slot, and the other end of spring guide shaft 3-9 is spaced from the bottom of the slot, with spring 3-10 sleeved on spring guide shaft 3-9 for orientation; a pin 3-13 is installed at the other end of force transmission rod 3-12; the outer diameter of the T-shaped head is equal to the inner diameter of the large cylinder of pressure sensor base 3-5, and the force transmission part below the T-shaped head... The outer diameter of rod 3-12 is equal to the inner diameter of the small cylinder of pressure sensor seat 3-5. The fixing sleeve 3-7 is located in the upper half of the large cylinder diameter of pressure sensor seat 3-5. The T-shaped head of force transmission rod 3-12 is stuck in the lower half of the large cylinder diameter of pressure sensor seat 3-5. A return spring 3-11 is circumferentially arranged in the middle of force transmission rod 3-12. The end of pressure sensor seat 3-5 contacts the return spring 3-11. Anti-rotation screw and set screw 3-8 pass radially through pressure sensor seat 3-5 and sleeve 3-7 in sequence, fixing sleeve 3-7 on pressure sensor seat 3-5 to prevent it from rotating. The distance adjustment module 4 includes a micrometer 4-1, a transmission module pad 4-2, a vertical support 4-3, a push rod 4-4, a fatigue test block 4-5, a fatigue test block fixing seat 4-6, a connecting plate 4-7, a slider 4-8, a guide rail 4-9, and a distance adjustment module pad 4-10. The transmission module pad 4-2 has a through hole for the force transmission module 3 to pass through. The micrometer 4-1 is mounted on one side of the transmission module pad 4-2 via the vertical support 4-3. One side of the push rod 4-4 contacts the micrometer 4-1, and the other side is connected to the fatigue test block fixing seat 4-6. The fatigue test block 4-5 is fixed to the top of the fatigue test block fixing seat 4-6, and the bottom is connected to the connecting plate 4-7. The bottom of the connecting plate 4-7 is fixed to the slider 4-8, and the top of the guide rail 4-9 carries the slider 4-8 and is fixed to the distance adjustment module pad 4-10. Furthermore, the load-bearing frame module 1 includes a support foot 1-1, a sheet metal shell 1-2, a lower surface plate 1-3, and an upper surface plate 1-4; the support foot 1-1 is threaded at the top, passes through the interior of the sheet metal shell 1-2 from bottom to top, and is connected to the lower surface plate 1-3, which has a threaded hole and is located at the top of the sheet metal shell 1-2; the lower surface plate 1-3 is connected to the upper surface plate 1-4, which has a countersunk through hole. Furthermore, the through holes of the lower surface plate 1-3 and the upper surface plate 1-4 should coincide to facilitate the stable operation of the motion control module 2; the grooves provided on the surfaces of the lower surface plate 1-3 and the upper surface plate 1-4 should be the same size as the transmission module pad 4-2 and the distance adjustment module pad 4-10, respectively, to prevent vibration during fatigue testing.

[0008] Further, the fixing mechanism 2-4 includes a fixed vertical plate Ia, a lead screw fixing seat b, a fixed plate c, a lead screw d, a fixed vertical plate IIe, a stop nut f, a lead screw support seat g, a support plate h, and ribs i. The fixed vertical plates Ia and IIe are located on both sides of the lead screw d, and are installed on the load-bearing frame module 1 (preferably on the upper surface plate 1-4 with grooves), and are fixed by four identical ribs i on the periphery. A fixed plate c and a support plate h connect the fixed vertical plates Ia and IIe. One end of the lead screw d is fixed to the lead screw fixing seat b located on the fixed plate c, passes through the lead screw support seat g installed on the support plate h, and is fixed by the stop nut f to prevent axial movement. The other end is connected to the plum blossom coupling 2-3, which has a keyway inside for transmission with the cam 3-1.

[0009] Furthermore, the end of the pressure sensor seat 3-5 contacts one end of the reset spring 3-11, and the other end of the reset spring 3-11 contacts the stepped hole inside the transmission module pad 4-2. When the cam 3-1 performs the push stroke, the reset spring 3-11 is compressed; when the cam 3-1 performs the return stroke, the reset spring 3-11 is released, restoring the pressure sensor seat 3-5 to its original position.

[0010] Furthermore, the slider 4-8 uses a smooth bearing inside, which ensures high precision and generates very little noise when sliding. It is equipped with a locking device inside, which can be self-locked by relying on the handwheel.

[0011] A fatigue testing method for a holding force probe, comprising the following steps: Stepper motor 2-2 drives force transmission module 3 to start moving, and pin 3-13 begins to reciprocate. Rotating micrometer 4-1 controls push rod 4-4 to move, which in turn pushes fatigue test block holder 4-6, fatigue test block 4-5, connecting plate 4-7, and slider 4-8 to slide on guide rail 4-9. When pin 3-13 contacts fatigue test block 4-5, pressure is generated. This pressure is transmitted to pressure sensor 3-6 via force transmission rod 3-12 and spring 3-10. Analog-to-digital converter 2-7 receives the analog signal from pressure sensor 3-6, quantizes and encodes it into a digital signal, and observes the pressure data. Simultaneously, micrometer 4-1 rotates to push fatigue test block 4-5, maintaining the holding force within the specified range. Once the pressure reading meets the requirements, the holding force is tested multiple times until the specified number of tests is reached, thus completing one fatigue test.

[0012] Compared with the prior art, the present invention achieves the following technical effects: The present invention provides an accelerated fatigue holding force testing device that can simulate the holding force detection process of the holding force probe, and the holding force can be adjusted as needed, effectively improving the reliability of the holding force probe in long-term operation. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the embodiments will be briefly introduced below.

[0014] Figure 1 This is an overall structural diagram of a fatigue testing device for holding force probes.

[0015] Figure 2 This is a structural diagram of the fixing mechanism of a fatigue testing device for holding force probes.

[0016] Figure 3 This is a structural diagram of the load-bearing frame module of a fatigue testing device for holding force probes.

[0017] Figure 4 This is a structural diagram of the motion control module of a fatigue testing device for holding force probes.

[0018] Figure 5(a) is a structural diagram of the force transmission module of a fatigue testing device for holding force probes.

[0019] Figure 5(b) is a cross-sectional view of the force transmission module of a fatigue testing device for holding force probes.

[0020] Figure 6 This is a structural diagram of the distance adjustment module of a fatigue testing device for holding force probes.

[0021] Figure 7 This is a fatigue test data graph for a holding force probe.

[0022] In the diagram: 1-Supporting frame module, 2-Motion control module, 3-Force transmission module, 4-Distance adjustment module, 1-1-Supporting foot, 1-2-Sheet metal housing, 1-3-Lower surface plate, 1-4-Upper surface plate, 2-1-Stepper motor driver, 2-2-Stepper motor, 2-3-Crown coupling, 2-4-Fixing mechanism, 2-5-Power supply, 2-6-Microcontroller, 2-7-Analog-to-digital converter, 3-1-Cam, 3-2-Polyurethane bearing, 3-3-Bearing mounting base, 3-4-Pressure sensor mounting. Plate, 3-5-Pressure sensor holder, 3-6-Pressure sensor, 3-7-Sleeve, 3-8-Anti-rotation screw and set screw, 3-9-Spring guide shaft, 3-10-Spring, 3-11-Reset spring, 3-12-Force transmission rod, 3-13-Pin, 4-1-Micrometer, 4-2-Transmission module pad, 4-3-Vertical bracket, 4-4-Push rod, 4-5-Fatigue test block, 4-6-Fatigue test block fixing seat, 4-7-Connecting plate, 4-8-Slider, 4-9-Guide rail, 4-10-Pad. a-Fixed vertical plate I, b-Screw fixing seat, c-Fixed plate, d-Screw, e-Fixed vertical plate II, f-Stop nut, g-Screw support seat, h-Support plate, i-Rib plate. Detailed Implementation

[0023] The specific embodiments of the present invention are described in detail below with reference to the technical solutions and accompanying drawings.

[0024] Specific Implementation Case 1 A fatigue testing device for holding force probe mainly consists of a load-bearing frame module 1, a motion control module 2, a force transmission module 3, and a distance adjustment module 4.

[0025] The load-bearing frame module 1 mainly consists of support feet 1-1, sheet metal housing 1-2, lower surface plate 1-3, and upper surface plate 1-4. The lower surface plate 1-3 has threaded holes, and its bottom is threaded to both the support feet 1-1 and the sheet metal housing 1-2. Its top is connected to the upper surface plate 1-4, which has countersunk holes, using hex socket screws. The motion control module 2 is located inside and on the top of the sheet metal housing 1-2. The upper surface plate 1-4 has a groove, and the lower surface plate 1-3 has a through hole at the same position as the groove in the upper surface plate 1-4 for connecting the distance adjustment module 4.

[0026] The motion control module 2 includes a stepper motor driver 2-1, a stepper motor 2-2, a perforated coupling 2-3, a fixing mechanism 2-4, a power supply 2-5, a microcontroller 2-6, and an analog-to-digital converter 2-7. The stepper motor driver 2-1 is mounted on the lower layer of the sheet metal housing 1-2 using hexagonal screws and nuts. The stepper motor 2-2 passes through through holes in the lower surface plate 1-3 and the upper surface plate 1-4 and connects to the perforated coupling 2-3. The fixing mechanism 2-4 is mounted on the upper surface plate 1-4, which has grooves, and its ribs are also mounted on the upper surface plate 1-4. The power supply 2-5 is mounted on the upper layer of the sheet metal housing 1-2 using hexagonal screws and nuts. The microcontroller 2-6 is mounted on the upper surface plate 1-4.

[0027] The force transmission module 3 includes a cam 3-1, a polyurethane bearing 3-2, a bearing mounting base 3-3, a pressure sensor mounting plate 3-4, a pressure sensor seat 3-5, a pressure sensor 3-6, a sleeve 3-7, an anti-rotation screw and a set screw 3-8, a spring guide shaft 3-9, a spring 3-10, a return spring 3-11, a force transmission rod 3-12, and a pin 3-13. The cam 3-1 is connected to the lead screw of the motion control module 2 via a key. One end of the bearing mounting base 3-3 has a threaded hole for connecting the polyurethane bearing 3-2, and the other end has a through hole for connecting the pressure sensor mounting plate 3-4. Pressure sensor holder 3-5 and pressure sensor 3-6 are mounted on pressure sensor mounting plate 3-4. Pressure sensor holder 3-5 has a stepped hole inside to limit the position of force transmission rod 3-12. A return spring 3-11 is connected to the end of pressure sensor holder 3-5. The function of return spring 3-11 is to ensure that polyurethane bearing 3-2 can make tight contact with cam 3-1 during its return stroke, preventing collision. Pressure sensor 3-6 is surrounded by sleeve 3-7 to prevent interference. Pressure sensor 3-6 has a threaded hole at its end for connecting spring guide shaft 3-9, and a spring 3-10 is fitted outside to guide spring 3-10. Force transmission rod 3-12 has a standard threaded hole at its end for connecting pin 3-13, allowing for quick replacement and use depending on the type of pin or socket.

[0028] The distance adjustment module 4 includes a micrometer 4-1, a transmission module pad 4-2, a vertical support 4-3, a push rod 4-4, a fatigue test block 4-5, a fatigue test block fixing seat 4-6, a connecting plate 4-7, a slider 4-8, a guide rail 4-9, and a distance adjustment module pad 4-10. The micrometer 4-1 passes through the vertical support 4-3, which has a through hole, and is in close contact with the push rod 4-4. The transmission module pad 4-2 has a groove with a threaded hole inside for connecting to the vertical support 4-3. The transmission module pad 4-2 and the distance adjustment module pad 4-10 are mounted on the lower surface plate 1-3, which has a through hole. The upper surface plate 1-4, located between the two, has a groove for positioning the transmission module pad 4-2 and the distance adjustment module pad 4-10. The guide rail 4-9, slider 4-8, connecting plate 4-7, fatigue test block fixing seat 4-6, and fatigue test block 4-5 are sequentially connected to the distance adjustment module pad 4-10. The slider 4-8 can slide on the guide rail 4-9 or be fixed by a handwheel; the surface of the slider 4-8 is fixed with the connecting plate 4-7. The fatigue test block fixing seat 4-6 has a countersunk hole at the bottom to connect to the connecting plate 4-7; the side wing has a threaded hole for connecting the push rod 4-4; its top has a groove with a countersunk hole for connecting the fatigue test block 4-5.

[0029] Example 2 This embodiment provides a fatigue testing method for a holding force probe, using the fatigue testing device for a holding force probe described in Embodiment 1, including: Step 1: Install the holding force probe, and fix the anti-rotation screw and set screw 3-8 to prevent the probe from rotating; Step 2: Insert the SD card into the microcontroller and start the microcontroller. Adjust the fatigue test block 4-5 according to the holding force requirement. The specific process is as follows: Microcontroller 2-6 is started, at which point stepper motor 2-2 begins to drive force transmission module 3 to move, and pin 3-13 begins to reciprocate. Micrometer 4-1 is rotated, causing it to control push rod 4-4 to move, which in turn pushes fatigue test block fixing seat 4-6, fatigue test block 4-5, connecting plate 4-7, and slider 4-8 to slide on guide rail 4-9. When pin 3-13 contacts fatigue test block 4-5, pressure is generated, which is transmitted to pressure sensor 3-6 via force transmission rod 3-12 and spring 3-10. Analog-to-digital converter 2-7 receives the analog signal from pressure sensor 3-6, quantizes and encodes it, converts it into a digital signal, and displays it. The pressure reading is observed. Simultaneously, micrometer 4-1 is rotated to push fatigue test block 4-5, changing the distance between pin 3-13 and fatigue test block 4-5. When pin 3-13 contacts fatigue test block 4-5 during holding force detection, the holding force generated will change, thus the holding force can be set according to requirements.

[0030] Step 3: Once the pressure reading meets the requirements, restart the microcontroller 2-6; Step 4: After the fatigue test is completed, remove the SD card, read and organize the experimental data.

[0031] Figure 7 The chart shows data from a fatigue test. A total of 12,000 holding force tests were conducted. The mean holding force was 8.96827 N, the standard deviation was 0.03202, the minimum was 8.82 N, the maximum was 9.13 N, and the median was 8.97 N. The holding force remained within ±3% of the acceptable range.

Claims

1. A fatigue testing device for a holding force probe, characterized in that, The fatigue testing device includes a load-bearing frame module (1), a motion control module (2), a force measurement and transmission module (3), and a distance adjustment module (4). The top of the load-bearing frame module (1) is equipped with the motion part of the motion control module (2) and the distance adjustment module (4), and the control part of the motion control module (2) is installed inside the load-bearing frame module (1); The motion control module (2) includes a motion part and a control part. The motion part includes a plum blossom coupling (2-3), a fixing mechanism (2-4), and a microcontroller (2-6). The control part includes a stepper motor driver (2-1), a stepper motor (2-2), a power supply (2-5), and an analog-to-digital converter (2-7). The stepper motor driver (2-1) is connected to the stepper motor (2-2). The stepper motor (2-2) is connected to the plum blossom coupling (2-3). The fixing mechanism (2-4) and the microcontroller (2-6) are mounted on the top of the load-bearing frame module (1). The fixing mechanism (2-4) is used to drive the plum blossom coupling (2-3) and connects the plum blossom coupling (2-3) to the screw (d) via a lead screw (d). 3) The motion is transmitted to the cam (3-1); the microcontroller (2-6) controls the stepper motor driver (2-1) to provide power to the stepper motor (2-2) to drive the force transmission module (3); the analog-to-digital converter (2-7) is used to convert the analog signal of the pressure sensor (3-6) into a digital signal; the power supply (2-5) provides voltage to the stepper motor driver (2-1), the stepper motor (2-2), the microcontroller (2-6) and the analog-to-digital converter (2-7); the fixing mechanism (2-4) includes a frame and a lead screw (d), the frame is fixed to the top of the load-bearing frame module (1) to support the lead screw (d) and make the axis of the lead screw (d) perpendicular to the plane of the load-bearing frame module (1); The force transmission module (3) includes a cam (3-1), a polyurethane bearing (3-2), a bearing mounting base (3-3), a pressure sensor mounting plate (3-4), a pressure sensor base (3-5), a pressure sensor (3-6), a sleeve (3-7), an anti-rotation screw and a set screw (3-8), a spring guide shaft (3-9), a spring (3-10), a return spring (3-11), a force transmission rod (3-12), and a pin (3-13). The cam (3-1) adopts a sinusoidal correction curve. The axial direction of the cam (3-1) is connected to the lead screw (d) of the motion control module (2) by a key. The rotation of the plum blossom coupling (2-3) can drive the cam (3-1) to rotate. The cam (3-1) contacts the polyurethane bearing (3-2) circumferentially; the polyurethane bearing (3-2) is mounted on one end of the bearing mounting base (3-3); the other end of the bearing mounting base (3-3) is connected to one side of the pressure sensor mounting plate (3-4), and the middle of the other side of the pressure sensor mounting plate (3-4) is fixed to one end of the pressure sensor (3-6), and the periphery is connected to the pressure sensor seat (3-5); the pressure sensor seat (3-5) is cylindrical, and the inner diameter of the cylinder is divided into two sections. The section closer to the pressure sensor mounting plate (3-4) has a larger diameter, and the section farther from the pressure sensor mounting plate (3-4) has a smaller diameter. The pressure sensor (3-6) is located in the section with the larger diameter, and the pressure sensor (3-1) is located in the section with the larger diameter. 6) A sleeve (3-7) is fixed between the pressure sensor holder (3-5) and the cylinder wall; the other end of the pressure sensor (3-6) is connected to one end of the spring guide shaft (3-9), and the pressure sensor (3-6) is also electrically connected to the analog-to-digital converter (2-7); one end of the force transmission rod (3-12) is a T-shape with a slot at the end, the spring (3-10) is located in the slot, the other end of the spring guide shaft (3-9) is spaced from the bottom of the slot, and the spring (3-10) is sleeved on the spring guide shaft (3-9) to achieve orientation; a pin (3-13) is installed at the other end of the force transmission rod (3-12); the outer diameter of the T-shaped head is equal to the inner diameter of the large cylinder of the pressure sensor holder (3-5), and the part below the T-shaped head... The outer diameter of the force transmission rod (3-12) is equal to the inner diameter of the small cylinder of the pressure sensor seat (3-5). The fixing sleeve (3-7) is located in the upper half of the large cylinder diameter of the pressure sensor seat (3-5). The T-shaped head of the force transmission rod (3-12) is stuck in the lower half of the large cylinder diameter of the pressure sensor seat (3-5). A return spring (3-11) is circumferentially arranged in the middle of the force transmission rod (3-12), and the end of the pressure sensor seat (3-5) contacts the return spring (3-11). The anti-rotation screw and the set screw (3-8) pass radially through the pressure sensor seat (3-5) and the sleeve (3-7) in sequence, fixing the sleeve (3-7) on the pressure sensor seat (3-5) to prevent it from rotating. The distance adjustment module (4) includes a micrometer (4-1), a transmission module pad (4-2), a vertical support (4-3), a push rod (4-4), a fatigue test block (4-5), a fatigue test block fixing seat (4-6), a connecting plate (4-7), a slider (4-8), a guide rail (4-9), and a distance adjustment module pad (4-10). The transmission module pad (4-2) has a through hole for the force transmission module (3) to pass through, and the micrometer (4-1) to pass through the vertical support. The seat (4-3) is located on one side of the transmission module pad (4-2); the push rod (4-4) is in contact with the micrometer (4-1) on one side and connected to the fatigue test block fixing seat (4-6) on the other side; the fatigue test block fixing seat (4-6) fixes the fatigue test block (4-5) on the top and connects to the connecting plate (4-7) at the bottom; the connecting plate (4-7) fixes the slider (4-8) at the bottom and the guide rail (4-9) supports the slider (4-8) on the top and is fixed on the distance adjustment module pad (4-10).

2. The fatigue testing device for holding force probe according to claim 1, characterized in that, The load-bearing frame module (1) includes a support foot (1-1), a sheet metal shell (1-2), a lower surface plate (1-3), and an upper surface plate (1-4). The support foot (1-1) is threaded at the top and passes through the inside of the sheet metal shell (1-2) from bottom to top, connecting with the lower surface plate (1-3) which has a threaded hole and is located at the top of the sheet metal shell (1-2). The lower surface plate (1-3) is connected to the upper surface plate (1-4) which has a countersunk through hole.

3. The fatigue testing device for holding force probe according to claim 2, characterized in that, The positions of the through holes of the lower surface plate (1-3) and the upper surface plate (1-4) should coincide to facilitate the stable operation of the motion control module (2); the grooves set on the surfaces of the lower surface plate (1-3) and the upper surface plate (1-4) should be the same size as the transmission module pad (4-2) and the distance adjustment module pad (4-10) respectively to prevent vibration during fatigue testing.

4. The fatigue testing device for holding force probe according to claim 1, characterized in that, The fixing mechanism (2-4) includes a fixed vertical plate I (a), a screw fixing seat (b), a fixing plate (c), a screw (d), a fixed vertical plate II (e), a stop nut (f), a screw support seat (g), a support plate (h), and a rib plate (i). The fixed vertical plate I (a) and the fixed vertical plate II (e) are located on both sides of the screw (d), which are installed on the load-bearing frame module (1) and fixed by four identical rib plates (i) on the periphery. A fixing plate (c) and a support plate (h) are connected between the fixed vertical plate I (a) and the fixed vertical plate II (e). One end of the screw (d) is fixed on the screw fixing seat (b) located on the fixing plate (c), passes through the screw support seat (g) installed on the support plate (h), and is fixed by the stop nut (f) to prevent axial movement. The other end is connected to the plum blossom coupling (2-3), which has a keyway inside for transmission with the cam (3-1).

5. The fatigue testing device for holding force probe according to claim 1, characterized in that, The end of the pressure sensor seat (3-5) contacts one end of the reset spring (3-11), and the other end of the reset spring (3-11) contacts the stepped hole inside the transmission module pad (4-2). When the cam (3-1) performs the push stroke, the reset spring (3-11) is compressed; when the cam (3-1) performs the return stroke, the reset spring (3-11) is released, restoring the pressure sensor seat (3-5) to its original position.

6. The fatigue testing device for holding force probe according to claim 1, characterized in that, The slider (4-8) uses a smooth bearing inside, which ensures high precision and produces very little noise when sliding. It is equipped with a locking device inside, which can be self-locked by handwheel.

7. A method for conducting fatigue testing of a holding force probe using a holding force probe fatigue testing device according to any one of claims 1-6, characterized in that, The steps are as follows: The stepper motor (2-2) drives the force transmission module (3) to start moving, and the pin (3-13) starts to move back and forth. The micrometer (4-1) is rotated, which causes the control push rod (4-4) to move, thereby pushing the fatigue test block fixing seat (4-6), fatigue test block (4-5), connecting plate (4-7) and slider (4-8) to slide on the guide rail (4-9). When the pin (3-13) contacts the fatigue test block (4-5), pressure is generated, which is transmitted to the pressure sensor (3-6) through the force transmission rod (3-12) and spring (3-10). Then the analog-to-digital converter (2-7) receives the analog signal transmitted from the pressure sensor (3-6), quantizes and encodes it and converts it into a digital signal to observe the pressure data. At the same time, the micrometer (4-1) is rotated to push the fatigue test block (4-5) to keep the holding force within the specified range. After the pressure reading meets the requirements, the holding force is tested multiple times until the specified number of times is reached, and one fatigue test ends.

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