Knob durability test device and operation method thereof

Abstract

The invention belongs to the technical field of automobile parts, and discloses a knob durability test device and an operation method thereof. The device comprises a clamping device, a connecting rod, an output device, a first cross shaft and a second cross shaft, the clamping device is fixed to a rotary knob, a first universal fork is installed on the clamping device, a second universal fork is installed on one side of the connecting rod, a third universal fork is installed at the other end of the connecting rod, and the output device drives a fourth universal fork to rotate along the axis of the fourth universal fork. A first shaft body and a second shaft body are rotatably mounted on the first cross shaft, a third shaft body and a fourth shaft body are rotatably mounted on the second cross shaft, a first universal fork is connected with the first shaft body, a second universal fork is connected with the second shaft body, a third universal fork is connected with the third shaft body, and a fourth universal fork is connected with the fourth shaft body; the problems that in the prior art, due to the fact that a shaft body for clamping a rotary knob does not coincide with the axis of the rotary knob, the rotary knob is damaged abnormally, and the final experiment result is affected are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive parts, and particularly to a knob durability test device and an operation method thereof. Background Art

[0002] There are a large number of durability tests for the knobs of air-conditioning operation panels in the annual development and re-inspection of commercial vehicles. Generally, the durability tests for the knobs of air-conditioning operation panels need to be rotated more than 100,000 times, and the test cycle is more than half a month. As the core component of human-machine interaction, the reliability of the air-conditioning operation panel directly affects the vehicle use quality and user satisfaction. Therefore, the structural strength and reliability of air-conditioning parts must meet the design standards. According to the requirements of GB / T 24550-2021 "Automobile Safety and Reliability Test Methods" and ISO 16750-3:2012 Road Vehicles Electrical and Electronic Equipment Environmental Test Standards, the knobs of air-conditioning operation panels need to pass more than 100,000 times of rotational durability tests, and a single complete test cycle usually requires 15-22 working days. Taking a heavy commercial vehicle production enterprise as an example, the annual durability test volume of air-conditioning knobs involved in the development of new products and the re-inspection of in-production models can reach more than 300 groups, and the operation time of a single project test equipment exceeds 6,000 hours. In the previous tests, the knob clamping device of the test equipment could not be reliably connected to the knob of the air-conditioning operation panel. Sometimes, the clamping device became loose from the knob before half of the test was completed. The traditional three-jaw mechanical or other forms of clamping devices used in the test equipment had significant structural limitations. The matching of its contact surface friction coefficient (μ≈0.3-0.4) with the knob surface treatment process (usually ABS+PC chrome plating or POM engineering plastics) was poor, and relative slip was likely to occur during continuous rotation. Test data showed that when the number of rotations reached 42,000-56,000 times, the contact pressure between the clamping device and the knob decreased by 32%-45%, resulting in the need to stop the machine to re-tighten the fixture every 3.5 hours on average during the test, seriously affecting the test continuity. A typical failure record showed that 7 accidental loosening occurred during 72 hours of continuous test, directly resulting in a 42% extension of the test cycle, and requiring the test personnel to frequently stop the machine for inspection, increasing the time cost and labor consumption.

[0003] In addition, in the previous clamping device for the durability test of the air conditioner operation panel knob and the loading motor for the test, a rigid connection was adopted. Usually, the output shaft of the motor was directly connected to the knob. If the axis of the motor did not coincide with the axis of the knob, this would cause the rotation center of the clamping device to deviate from the rotation center of the knob and the rotation center of the loading motor, resulting in abnormal load on the rotating shaft. When there were cumulative tolerances among the motor output shaft (tolerance grade IT6), the fixture connecting sleeve (IT7), and the knob shaft (IT8), the coaxiality deviation of the system could reach 0.15 - 0.25 mm. This deviation would generate a periodic radial load during rotation, and its amplitude could be calculated by the formula F_r = meω2 (where m is the rotating mass, e is the eccentricity, and ω is the angular velocity). At a typical test speed (30 rpm), the radial alternating stress generated by an eccentricity of 0.2 mm could reach 18 - 22 N, resulting in a 60% - 70% reduction in the fatigue life of the rotating shaft. The rotating shaft would be subjected to stress perpendicular to the axis of the rotating shaft, leading to early damage of the rotating shaft body. Each time a new test sample was replaced, careful adjustment was required to ensure coaxiality, which wasted a lot of verification time. The non-ideal clamping state caused a deviation between the actual force on the knob and the design load. Finite element analysis showed that when the clamping contact area was less than 75% of the design value, the stress concentration coefficient inside the knob would increase by 2.1 - 2.8 times, which might cause false positives (premature failure) or false negatives (undetected potential defects) in the test results. Comparative test data showed that for samples of the same batch under different clamping states, the dispersion of the failure cycle times reached ±18%, seriously affecting the credibility of the test results. Once the three were not in the concentric position, the air conditioner operation panel knob would rotate eccentrically, which would accelerate the failure or damage of the knob and increase the design cost of the knob. Summary of the Invention

[0004] The purpose of the present invention is to provide a knob durability test device and its operation method, which solve the problem that in the prior art, due to the non-coincidence of the axis of the shaft clamping the knob and the axis of the knob, the knob will be abnormally damaged, affecting the final test results.

[0005] To achieve this purpose, the present invention adopts the following technical solutions: The present invention provides a knob durability test device, including a clamping device, a connecting rod, an output device, a first cross shaft, and a second cross shaft. The clamping device is fixed on the knob. A first universal joint fork is installed on the clamping device. One side of the connecting rod is installed with a second universal joint fork, and the other side is installed with a third universal joint fork. The output device drives a fourth universal joint fork to rotate along its own axis. A first shaft body and a second shaft body are rotatably installed on the first cross shaft. The first shaft body and the second shaft body are perpendicular. A third shaft body and a fourth shaft body are rotatably installed on the second cross shaft. The third shaft body and the fourth shaft body are perpendicular. The first universal joint fork is connected to the first shaft body, the second universal joint fork is connected to the second shaft body, the third universal joint fork is connected to the third shaft body, and the fourth universal joint fork is connected to the fourth shaft body.

[0006] Preferably, two groups of first fork bodies are symmetrically arranged along the axis of the first universal joint fork at the front end of the first universal joint fork. The first fork bodies are welded on the first shaft body, and the first fork bodies correspond to the first shaft body one by one.

[0007] Preferably, two groups of second fork bodies are symmetrically arranged along the axis of the second universal joint fork at the front end of the second universal joint fork. The second fork bodies are welded on the second shaft body, and the second fork bodies correspond to the second shaft body one by one.

[0008] Preferably, two groups of third fork bodies are symmetrically arranged along the axis of the third universal joint fork at the front end of the third universal joint fork. The third fork bodies are welded on the third shaft body, and the third fork bodies correspond to the third shaft body one by one.

[0009] Preferably, two groups of fourth fork bodies are symmetrically arranged along the axis of the fourth universal joint fork at the front end of the fourth universal joint fork. The fourth fork bodies are welded on the fourth shaft body, and the fourth fork bodies correspond to the fourth shaft body one by one.

[0010] Preferably, the clamping device includes a first cover body. The first cover body is cylindrical. A first opening is formed on one side along the axis direction of the first cover body, and a first cover plate is arranged on the other side. The first opening is sleeved on the knob. A first screw hole is formed on the first cover body. A first threaded column is installed on the side of the first universal joint fork away from the first fork body, and the first threaded column is screwed into the first screw hole.

[0011] Preferably, a first fixing hole is formed on the arc surface of the first cover body. Internal threads are formed in the first fixing hole. A first fixing screw is screwed into the first fixing hole, and the first fixing screw abuts against the knob.

[0012] Preferably, a second cover body is sleeved on the output shaft of the output device. The second cover body is cylindrical. A second opening is formed on one side along the axis direction of the second cover body, and a second cover plate is arranged on the other side. The second opening is sleeved on the output shaft. A second screw hole is formed on the second cover plate. A second threaded column is installed on the side of the fourth universal joint fork away from the fourth fork body, and the second threaded column is screwed into the second screw hole.

[0013] Preferably, a second fixing hole is formed on the arc surface of the second cover body. Internal threads are formed in the second fixing hole. A second fixing screw is screwed into the second fixing hole, and the second fixing screw abuts against the output shaft.

[0014] An operation method of a knob durability test device includes the above-mentioned knob durability test device, and further includes the following steps:

[0015] S1. The first cover is sleeved on the knob; the first fixing screw is screwed in so that the first fixing screw abuts against the knob;

[0016] S2. The first threaded post of the first universal fork is screwed into the first threaded hole;

[0017] S3. The second cover is sleeved on the output shaft; the second fixing screw is screwed in so that the second fixing screw abuts against the output shaft;

[0018] S4. The second threaded post of the fourth universal fork is screwed into the second threaded hole;

[0019] S5. Start the output device to drive the output shaft to rotate.

[0020] Beneficial effects: After the knob is connected to the clamping device, the output device drives the fourth universal fork to rotate. The fourth universal fork will drive the second cross shaft to rotate. The second cross shaft drives the third universal fork to rotate, and the connecting rod rotates. The second universal fork on the other side will also rotate. Finally, the second universal fork drives the first cross shaft to rotate, so that the first universal fork on the first cross shaft drives the clamping device to rotate, and the clamping device can drive the knob to rotate. Since the structure of a cardan shaft universal coupling is formed by the first cross shaft and the second cross shaft, the cardan shaft universal coupling can transmit torque under different axis conditions, enabling the knobs at both ends of the connecting rod and the knob of the output device to transmit torque on different axes, so that the axis of the output device does not need to be aligned with the axis of the knob in the clamping device. At the same time, the impact of the radial force of the output device on the axis direction of the knob is eliminated, reducing the interference items in the knob durability test and increasing the accuracy of the knob durability test results. Description of the Drawings

[0021] Figure 1 is the front view of the first cover of the present invention;

[0022] Figure 2 is the front view of the first universal fork of the present invention;

[0023] Figure 3 is the front view of the fourth universal fork of the present invention;

[0024] Figure 4 is the main view of the connecting rod of the present invention;

[0025] Figure 5 is the front view of the second cover of the present invention;

[0026] Figure 6 is the front view of the first cross shaft of the present invention;

[0027] Figure 7 is the front view of the second cross shaft of the present invention.

[0028] In the figure: 1. First cover body; 2. Connecting rod; 21. Second universal joint fork; 211. Second fork body; 22. Third universal joint fork; 221. Third fork body; 3. First cross shaft; 31. First shaft body; 32. Second shaft body; 4. Second cross shaft; 41. Third shaft body; 42. Fourth shaft body; 5. First universal joint fork; 51. First fork body; 52. First threaded post; 6. Fourth universal joint fork; 61. Fourth fork body; 62. Second threaded post; 7. First fixing screw; 8. Second fixing screw; 9. Second cover body. Detailed implementation manner

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of convenience of description, only the parts related to the present invention are shown in the drawings, rather than all the structures.

[0030] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "above", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "below", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature.

[0032] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0033] In the development and annual re-inspection of commercial vehicle complete vehicles, the durability test of the air-conditioning operation panel knob has a large demand and strict standards. Usually, more than 100,000 rotation operations are required for a single test, and the entire verification cycle needs to last for more than 15 days. There are two major technical pain points in the existing test equipment: First, the connection stability between the traditional knob clamping device and the air-conditioning panel knob is insufficient, and the fixture and the knob frequently disengage during the test, especially during the mid-stage of the test, the loosening phenomenon is significant, forcing the operator to repeatedly stop the machine for maintenance, which significantly increases the manual input and time loss of test management; Second, the current clamping device and the loading motor adopt a rigid direct connection structure. When the output shaft of the motor and the rotation axis of the knob are not completely coincident, the rotation center offset phenomenon will occur. This axis deviation not only causes abnormal radial stress on the rotating shaft, accelerating the fatigue damage of the rotating shaft, but also requires a large amount of time for coaxiality calibration every time the test sample is replaced. More seriously, the axis deviation of the three will force the knob to rotate eccentrically, and this abnormal working condition will greatly shorten the service life of the knob and at the same time push up the verification cost in the product R & D stage.

[0034] To solve the above problems, as Figures 1 to 7 shown, the present invention provides a knob durability test device, which includes a clamping device, a connecting rod 2, an output device, a first cross shaft 3 and a second cross shaft 4. The clamping device is fixed on the knob, and a first universal fork 5 is installed on the clamping device. One side of the connecting rod 2 is installed with a second universal fork 21 and the other end is installed with a third universal fork 22. The output device drives the fourth universal fork 6 to rotate along its own axis. The first cross shaft 3 is rotatably installed with a first shaft body 31 and a second shaft body 32. The first shaft body 31 and the second shaft body 32 are perpendicular. The second cross shaft 4 is rotatably installed with a third shaft body 41 and a fourth shaft body 42. The third shaft body 41 and the fourth shaft body 42 are perpendicular. The first universal fork 5 is connected to the first shaft body 31, the second universal fork 21 is connected to the second shaft body 32, the third universal fork 22 is connected to the third shaft body 41, and the fourth universal fork 6 is connected to the fourth shaft body 42.

[0035] The first cross shaft 3 and the second cross shaft 4 are common coupling components in a cross shaft type universal coupling. On both sides of the cross direction of the first cross shaft 3, a first universal fork 5 and a second universal fork 21 are respectively installed. The first universal fork 5 and the second universal fork 21 are inserted in a staggered manner and connected to the first cross shaft 3 at the same time. The shaft rod of the first cross shaft 3 is in a cross shape, and a freely rotatable first shaft body 31 and a second shaft body 32 are installed on each side of the shaft rod. The first universal fork 5 is sleeved on the first shaft body 31 through the opening on it, and the opening of the second universal fork 21 is sleeved on the second shaft body 32; Similarly, the third universal fork 22 and the fourth universal fork 6 on the other side of the connecting rod 2 are also inserted in a staggered manner through the second cross shaft 4. The opening on the third fork body 221 is sleeved on the third shaft body 41, and the opening of the fourth fork body 61 is sleeved on the fourth shaft body 42.

[0036] The output shaft of the output device drives the fourth universal fork 6 to rotate self - sufficiently, drives the connecting rod 2 to rotate, and the connecting rod 2 transmits the rotation to the knob of the clamping device, completing the transmission of torque so that the knob can perform a knob durability test.

[0037] According to the mechanical law of the cross - shaft universal coupling, it can be deduced that during the process of the connecting rod 2 transmitting the rotational torque, it can be in an inclined state compared with the horizontal plane, allowing the rotational axes of the clamping devices on both sides of the connecting rod 2 and the rotational axis of the output device not to be on the same axis. The abnormal radial force caused by the non - coincidence of the rotating shafts can be eliminated through the universal coupling components on both sides of the connecting rod 2, so that only the rotational torque exists on the knob. The reliability of the knob durability test structure obtained after measurement is higher. During the process of installing the knob, calibration is not required, saving the installation process before the test and reducing requirements.

[0038] At the front end of the first universal fork 5 of the present invention, two groups of first fork bodies 51 are symmetrically arranged along the axis of the first universal fork 5. The first fork bodies 51 are welded on the first shaft body 31, and the first fork bodies 51 correspond to the first shaft body 31 one by one. At the front end of the second universal fork 21, two groups of second fork bodies 211 are symmetrically arranged along the axis of the second universal fork 21. The second fork bodies 211 are welded on the second shaft body 32, and the second fork bodies 211 correspond to the second shaft body 32 one by one. At the front end of the third universal fork 22, two groups of third fork bodies 221 are symmetrically arranged along the axis of the third universal fork 22. The third fork bodies 221 are welded on the third shaft body 41, and the third fork bodies 221 correspond to the third shaft body 41 one by one. At the front end of the fourth universal fork 6, two groups of fourth fork bodies 61 are symmetrically arranged along the axis of the fourth universal fork 6. The fourth fork bodies 61 are welded on the fourth shaft body 42, and the fourth fork bodies 61 correspond to the fourth shaft body 42 one by one.

[0039] After each fork body is connected to the shaft body, it can be fixed by welding. The shaft body can drive the fork body to rotate, achieving the installation effect of the final universal coupling. The fork bodies of each group of universal forks are fixed to both sides of the cross - shaft, enabling the first cross - shaft 3 and the second cross - shaft 4 to be completely fixed circumferentially, improving the stability during rotation and reducing the vibration amplitude.

[0040] The clamping device includes a first cover body 1. The first cover body 1 is cylindrical. A first opening is provided on one side along the axis direction of the first cover body 1, and a first cover plate is provided on the other side. The first opening is sleeved on the knob. A first screw hole is provided on the first cover body 1. On the side of the first universal fork 5 away from the first fork body 51, a first threaded post 52 is installed, and the first threaded post 52 is screwed into the first screw hole.

[0041] The first universal fork 5 is installed on the first cover body 1 in a threaded - mounting form, which is convenient for subsequent disassembly and repair.

[0042] On the arc surface of the first cover body 1, a first fixing hole is provided. An internal thread is formed in the first fixing hole. A first fixing screw 7 is screwed into the first fixing hole, and the first fixing screw 7 abuts against the knob. Three or even more groups of first fixing screws 7 can be installed circumferentially on the first cover body 1 of the present invention, which can increase the stability of the connection to the knob. At the same time, the bottom of the first fixing screw 7 is a tip, which can be inserted into the side wall of the knob, reducing the probability of relative movement between the knob and the first cover body 1 during the process of the first cover body 1 driving the knob to rotate, reducing the number of inspections by the inspectors, and improving the efficiency of the test.

[0043] A second cover body 9 is sleeved on the output shaft of the output device of the present invention. The second cover body 9 is cylindrical. A second opening is provided on one side along the axis direction of the second cover body 9, and a second cover plate is provided on the other side. The second opening is sleeved on the output shaft. A second screw hole is provided on the second cover plate. A second threaded column 62 is installed on the side of the fourth universal joint fork 6 away from the fourth fork body 61, and the second threaded column 62 is screwed into the second screw hole.

[0044] Among them, the fourth universal joint fork 6 can also be detachably installed on the second cover body 9 through the second threaded column 62, which is convenient for subsequent disassembly and maintenance. The second fixing screw 8 can also increase the stability during the connection between the second cover body 9 and the output shaft. It should be particularly noted that the specifications of the first threaded column 52 and the second threaded column 62 are the same, which is convenient for unified processing. The specifications of the first fixing screw 7 and the second fixing screw 8 are also the same, which is convenient for unified procurement and reduces the types of parts.

[0045] On the arc surface of the second cover body 9, a second fixing hole is provided. An internal thread is formed in the second fixing hole. A second fixing screw 8 is screwed into the second fixing hole, and the second fixing screw 8 abuts against the output shaft. The specifications of the first fixing screw 7 and the second fixing screw 8 are also the same, which is convenient for unified procurement and reduces the types of parts. A handle can be welded on the upper sides of the first fixing screw 7 and the second fixing screw 8, and the handle is perpendicular to the axis of the screw, which is convenient for the operator to rotate.

[0046] The present invention also provides an operation method for a knob durability test device, including the following steps:

[0047] S1, the first cover body 1 is sleeved on the knob; the first fixing screw 7 is screwed in so that the first fixing screw 7 abuts against the knob;

[0048] S2, the first threaded column 52 of the first universal joint fork 5 is screwed into the first screw hole;

[0049] S3, the second cover body 9 is sleeved on the output shaft; the second fixing screw 8 is screwed in so that the second fixing screw 8 abuts against the output shaft;

[0050] S4, the second threaded column 62 of the fourth universal joint fork 6 is screwed into the second screw hole;

[0051] S5, start the output device to drive the output shaft to rotate.

[0052] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A knob durability test device, characterized in that: The invention comprises a clamping device, a connecting rod (2), an output device, a first cross shaft (3) and a second cross shaft (4); the clamping device is fixed on a knob; a first universal fork (5) is installed on the clamping device; a second universal fork (21) is installed on one side of the connecting rod (2) and a third universal fork (22) is installed on the other end; the output device drives the fourth universal fork (6) to rotate along its own axis; a first shaft body (31) and a second shaft body (32) are rotatably installed on the first cross shaft (3); The shaft (31) and the second shaft (32) are perpendicular to each other; the third shaft (41) and the fourth shaft (42) are rotatably mounted on the second cross shaft (4); the third shaft (41) and the fourth shaft (42) are perpendicular to each other; the first universal fork (5) is connected to the first shaft (31); the second universal fork (21) is connected to the second shaft (32); the third universal fork (22) is connected to the third shaft (41); and the fourth universal fork (6) is connected to the fourth shaft (42).

2. The knob durability test device according to claim 1, characterized in that: Two groups of first fork bodies (51) are symmetrically arranged at the front end of the first universal fork (5) along the axis of the first universal fork (5); the first fork bodies (51) are welded to the first shaft body (31); and the first fork bodies (51) correspond one to one to the first shaft body (31).

3. The knob durability test device according to claim 1, characterized in that: Two groups of second fork bodies (211) are symmetrically arranged at the front end of the second universal fork (21) along the axis of the second universal fork (21), and the second fork bodies (211) are welded to the second shaft body (32), and the second fork bodies (211) correspond one to one to the second shaft body (32).

4. The knob durability test device according to claim 1, characterized in that: Two groups of third fork bodies (221) are symmetrically arranged at the front end of the third universal fork (22) along the axis of the third universal fork (22); the third fork bodies (221) are welded to the third shaft body (41); and the third fork bodies (221) correspond one to one to the third shaft body (41).

5. The knob durability test device according to claim 2, characterized in that: Two groups of fourth fork bodies (61) are symmetrically arranged at the front end of the fourth universal fork (6) along the axis of the fourth universal fork (6); the fourth fork bodies (61) are welded to the fourth shaft body (42); and the fourth fork bodies (61) correspond one to one to the fourth shaft body (42).

6. The knob durability test device according to claim 5, characterized in that: The clamping device comprises a first cover body (1), the first cover body (1) is cylindrical, a first opening is provided on one side along the axis direction of the first cover body (1), and a first cover plate is provided on the other side, the first opening is sleeved on the knob, a first screw hole is provided on the first cover body (1), a first threaded column (52) is installed on the side of the first universal fork (5) away from the first fork body (51), and the first threaded column (52) is screwed into the first screw hole.

7. The knob durability test device according to claim 6, characterized in that: A first fixing hole is provided on the arc-shaped surface of the first cover body (1), an internal thread is formed in the first fixing hole, a first fixing screw (7) is screwed into the first fixing hole, and the first fixing screw (7) abuts against the knob.

8. The knob durability test device according to claim 7, characterized in that: A second cover body (9) is sleeved on the output shaft of the output device. The second cover body (9) is cylindrical and has a second opening on one side along the axial direction of the second cover body (9) and a second cover plate on the other side. The second opening is sleeved on the output shaft and a second screw hole is formed on the second cover plate. A second threaded column (62) is installed on the side of the fourth universal fork (6) away from the fourth fork body (61), and the second threaded column (62) is screwed into the second screw hole.

9. The knob durability test device according to claim 8, characterized in that: A second fixing hole is provided on the arc surface of the second cover body (9), an internal thread is formed in the second fixing hole, a second fixing screw (8) is screwed into the second fixing hole, and the second fixing screw (8) abuts against the output shaft.

10. A method for operating a knob durability test device, characterized in that: The knob durability test device according to claim 9 further comprises the following steps: S1, the first cover (1) is sleeved on the knob; the first fixing screw (7) is screwed in, so that the first fixing screw (7) abuts against the knob; S2, the first threaded column (52) of the first universal fork (5) is screwed into the first screw hole; S3, the second cover (9) is sleeved on the output shaft; the second fixing screw (8) is screwed in, so that the second fixing screw (8) abuts against the output shaft; S4, the second threaded column (62) of the fourth universal fork (6) is screwed into the second screw hole; S5, start the output device to drive the output shaft to rotate.

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