A bicycle synchronous belt fatigue testing device and a testing method thereof

Abstract

The application discloses a bicycle synchronous belt fatigue testing device and a testing method thereof. The testing device comprises a testing table, a simulation assembly and a control device. The simulation assembly comprises a synchronous belt driving device, a belt wheel offset device, a synchronous belt load device, a synchronous belt stretching device and a speed measuring device. The devices of the simulation assembly are connected with the control device and are controlled by the control device. The control device has a timing module, a display module and a control processing module. The synchronous belt driving device comprises a driving belt wheel, a driven belt wheel and a rotary motor. The driving belt wheel and the driven belt wheel are sleeved with a synchronous belt to be tested. The belt wheel offset device is arranged on a movable part of the rotary motor. The synchronous belt stretching device comprises a jacking piece and a transmission mechanism. The transmission mechanism is linked with the movable part of the rotary motor. The application can perform multiple road condition tests, increases the accuracy of the testing results, and the belt wheel offset device and the synchronous belt stretching device are linked through the rotary motor, thereby reducing the cost of the device.

Description

Technical Field

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

[0002] Synchronous toothed belts, also known as synchronous belts, are made with steel wire rope or fiberglass rope as the reinforcing layer, covered with polyurethane or neoprene rubber on the outside. The inner circumference of the belt is toothed so that it meshes with toothed pulleys. As an important component for power transmission, synchronous belts are widely used in the mechanical transmission of bicycles. Bicycles with synchronous belt drives use the pedals to rotate the drive pulley at the front of the bicycle, thereby achieving linkage with the driven pulley at the rear of the bicycle through the synchronous belt drive between the drive pulley and the synchronous belt.

[0003] In the production and R&D process of synchronous belts, it is necessary to simulate bicycle riding to conduct fatigue tests on the synchronous belts. Based on the wear condition of the synchronous belts, adjustments and corrections can be made to the materials, production process, and parameters of the synchronous belts, thereby improving them. For example, utility model patent CN206848091U discloses a bicycle belt fatigue testing device, including a test bench frame and a flywheel mounted on the test bench frame. The flywheel is connected to a sprocket via a chain, which is covered by a belt. Support seats are provided on both sides of the flywheel, and the support seats are mounted on the test bench frame. A control module is also provided on the test bench frame, and the control module is connected to a computer. The computer contains a software testing unit. A riding frame is connected below the flywheel, a speed measuring mechanism is located behind the flywheel, and a resistance structure is located on one side of the flywheel.

[0004] When riding a bicycle on uneven surfaces, there are situations where the wheels bounce over obstacles, causing the pulley to shift and the timing belt to become misaligned, or the timing belt comes into contact with obstacles and stretches. These issues affect the fatigue resistance of the timing belt during bicycle riding. Existing testing devices can usually only test the load fatigue of the timing belt pulley on level road conditions. The testing function is relatively limited and it is difficult to conduct a comprehensive fatigue test on the timing belt. This results in inaccurate fatigue test results for the timing belt. Additional equipment is needed to simulate different road conditions, which has poor applicability and increases the cost of the device. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the aforementioned technologies by designing a bicycle timing belt fatigue testing device and its testing method. This device can perform multiple road condition tests, increasing the accuracy of the test results. Furthermore, the pulley offset device and the timing belt tensioning device can be linked by a rotary motor, reducing the cost of the device.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: On one hand, the present invention provides a bicycle timing belt fatigue testing device, characterized in that: it includes a test bench, a simulation assembly and a control device disposed on the test bench, the simulation assembly includes a timing belt drive device, a pulley offset device, a timing belt load device, a timing belt tension device and a speed measuring device, each device of the simulation assembly is connected to and controlled by the control device, and the control device has a timing module, a display module and a control processing module; The synchronous belt drive device includes a driving pulley, a driven pulley, and a rotary motor. A synchronous belt to be tested is sleeved between the driving pulley and the driven pulley. The rotary motor is electrically connected to the control device. The driving pulley is provided with a sensing end. A sensor receiver that senses and cooperates with the sensing end is provided on the test platform near the driving pulley. The sensor receiver is electrically connected to the control device. The pulley offset device is disposed on the movable part of the rotary motor to drive the drive pulley to rotate in the initial position or to move back and forth and rotate in the swing position; The synchronous belt load device is movably connected to the test bench, and the synchronous belt load device is connected to the driven pulley to apply resistance to the driven pulley and to tension the synchronous belt under test between the driving pulley and the driven pulley; The synchronous belt stretching device includes a lifting member and a transmission mechanism. The lifting member is movably connected to the test bench between the driving pulley and the driven pulley. The transmission mechanism is linked with the movable part of the rotary motor to drive the lifting member to move up and down and to stretch and deform the synchronous belt under test. The speed measuring device includes a first speed sensor and a second speed sensor, used to detect the rotational speeds of the driving pulley and the driven pulley, respectively, and the control device controls the acquisition by the first speed sensor and the second speed sensor.

[0007] Preferably, the inner diameter of the driving pulley is larger than the inner diameter of the driven pulley.

[0008] Preferably, the pulley offset device includes a centering shaft and a drive disk. A connecting frame is provided on the test bench. The centering shaft is rotatably connected to the connecting frame and connected to the movable part of the rotary motor. The drive pulley is sleeved with the centering shaft. The drive disk is connected to the centering shaft. The drive disk is provided with at least one connecting part spaced apart from the centering shaft. The drive pulley is hollow inside and is provided with a connecting sleeve for the connecting part to be sleeved with.

[0009] Preferably, the pulley offset device further includes a guide plate, a first elastic element, and an adjusting element. The guide plate is spaced apart from the drive plate, and the drive pulley is located between the guide plate and the drive plate. A stop post is provided on the side wall of the drive pulley near the guide plate. The first elastic element acts between the drive plate and the drive pulley, causing the drive pulley to move closer to the guide plate along the axial direction of the centering shaft. The stop post abuts against the guide plate. The upper part of the guide plate is movably connected to the connecting frame, and the middle part of the guide plate is through to allow the centering shaft to move relative to it. The adjusting member is threadedly connected to the connecting frame, and the adjusting member passes through the end of the connecting frame and cooperates with the lower part of the guide plate.

[0010] The pulley offset device allows the axial direction of the guide disc to be either parallel or inclined to the axial direction of the centering shaft. When the axial direction of the guide disk is parallel to the axial direction of the centering shaft, the adjusting member supports the guide disk to keep it in its initial position, so as to maintain the parallelism between the guide disk and the opposite side of the drive pulley, and the drive pulley is positioned and rotated on the centering shaft; When the axial direction of the guide disc is tilted relative to the axial direction of the centering shaft, the adjusting member supports the guide disc to maintain it in a swing position, so as to keep the plane on which the guide disc and the opposite side of the drive pulley intersect. The drive pulley translates and rotates back and forth along the axial direction on the centering shaft.

[0011] Preferably, the synchronous belt load device includes an adjusting frame and a resistance device disposed on the adjusting frame. The adjusting frame is rotatably connected to an extension shaft. The driven pulley is connected to a first end of the extension shaft. The movable end of the resistance device and the second end of the extension shaft are both provided with first pulleys. A first transmission belt is sleeved between the two first pulleys and meshes with the first pulleys.

[0012] Preferably, the resistance device may be a rotary damper, a resistance motor, or a reduction gearbox.

[0013] Preferably, the test bench is provided with a guide rail for the adjustment frame to slide and connect, and a bogie is provided at the end of the guide rail away from the drive pulley. A counterweight plate is suspended on the bogie, and a flexible connector is connected between the counterweight plate and the adjustment frame. The bogie is rotatably connected with a steering wheel that abuts against the flexible connector.

[0014] Guided by the steering wheel, the counterweight disc pulls the driven pulley horizontally away from the driving pulley via a flexible connector, causing the synchronous belt under test to be tensioned between the driving pulley and the driven pulley. Preferably, the transmission mechanism includes a power shaft, a second transmission belt, and a drive cam. The power shaft is rotatably connected to the bottom of the test bench. A second pulley is provided at the first end of the power shaft and the movable part of the rotary motor. The second transmission belt is sleeved between the two second pulleys and meshes with them. The test bench has a through-hole for the second transmission belt to move. The drive cam is an eccentric wheel and is detachably connected to the second end of the power shaft. The test bench has a through-groove for the lifting member to slide. A guide shell is provided at the bottom of the test bench. The inner cavity of the guide shell communicates with the through-groove. The lower ends of the drive cam and the lifting member are both movable within the inner cavity of the guide shell. The lower end of the lifting member has a through-hole, and the inner wall of the drive hole abuts against the outer wall of the drive cam.

[0015] Preferably, the lower end of the lifting member includes a stroke block, the driving hole passes through the stroke block, the inner cavity of the guide shell includes a connected stroke groove and a mounting groove, the stroke block is slidably connected in the stroke groove, the mounting groove is located above the stroke groove and is provided with a second elastic member, the second elastic member acts between the mounting groove and the stroke block.

[0016] On the other hand, the present invention also provides a fatigue testing method for bicycle timing belts, which uses the above-mentioned testing device to perform fatigue testing on the timing belt under test, including the following steps: S1. Place the synchronous belt to be tested onto the driving pulley and the driven pulley, and preset the simulated mileage of the synchronous belt to be tested through the control device; S2. Move the synchronous belt load device to the test bench and adjust the distance between the driving pulley and the driven pulley so that the synchronous belt under test is tensioned between the driving pulley and the driven pulley; S3. According to the requirements, the active pulley is switched to the initial position or the swing position by the pulley offset device; S4. Start the rotary motor to make the active pulley rotate and drive the driven pulley to rotate synchronously through the synchronous belt under test. The sensor receiver records the number of rotations of the active pulley and feeds it back to the control processing module of the control device. After data processing, the data is fed back to the display module, so as to directly observe the real-time movement distance of the synchronous belt under test. S5. By using a synchronous belt load device to provide resistance to the rotation of the driven pulley, the load operation of the synchronous belt under test is simulated. S6. The synchronous belt is stretched and deformed during operation by using a synchronous belt stretching device to press against the synchronous belt to be tested. S7. The control device has a timing module to control the rotation motor to start and stop at intervals. The stop time of the rotation motor is set to 3s, and the start time of the rotation motor is set to 10s. The test is carried out continuously in this cycle. The control processing module of the control device analyzes the mileage of the synchronous belt under test and the preset simulated mileage. When the real-time mileage of the synchronous belt under test reaches the preset simulated mileage, the control device stops the rotation motor and takes out the synchronous belt under test to observe the damage on its surface.

[0017] Compared with the prior art, the beneficial effects of this utility model are: 1. This invention uses a rotary motor to drive the active pulley to rotate, which in turn drives the driven pulley to rotate via the synchronous belt under test. The pulley offset device is linked to the moving part of the rotary motor, so that the active pulley rotates at its initial position to simulate the operation of the synchronous belt under test on a level road, or the active pulley swings back and forth and rotates at a swing position to simulate the operation of the synchronous belt under test on a bumpy road. During this process, the synchronous belt load device applies resistance to the rotation of the driven pulley to simulate the load operation of the synchronous belt under test when a bicycle is riding. The synchronous belt tensioning device is linked to the moving part of the rotary motor through a transmission mechanism to lift the synchronous belt under test with a lifting member to simulate the operation of an obstacle against the synchronous belt under test, thereby increasing the accuracy of the test results.

[0018] 2. This invention uses a device to perform multiple road condition tests, and the pulley offset device and the synchronous belt tensioning device can be linked by a rotary motor, which reduces the cost of the device, has good applicability, and is convenient to use and operate. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the testing device in the embodiment. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the testing device in the embodiment. Figure 2 ; Figure 3 This is a cross-sectional view of the test device when the guide disk is held in the initial position in the embodiment; Figure 4 This is a cross-sectional view of the pulley offset device in the embodiment when the guide plate is held in the swing position. Figure 1 ; Figure 5 This is a cross-sectional view of the pulley offset device in the embodiment when the guide plate is held in the swing position. Figure 2 ; Figure 6 The compartment of the synchronous belt tensioning device in the embodiment. Figure 1 ; Figure 7 The compartment of the synchronous belt tensioning device in the embodiment. Figure 2 .

[0020] In the diagram: 1. Test bench; 2. Control device; 3. Synchronous belt drive device; 31. Driving pulley; 32. Driven pulley; 33. Rotary motor; 4. Pulley offset device; 41. Centering shaft; 42. Drive disc; 43. Guide disc; 44. First elastic element; 45. Adjusting element; 5. Synchronous belt load device; 51. Adjusting frame; 52. Resistance device; 6. Synchronous belt tensioning device; 61. Lifting element; 62. Transmission mechanism; 621. Power shaft; 622. Second transmission belt; 623. Drive cam; 7. Speed ​​measuring device; 71. First speed sensor 72. Second speed sensor; 8. Synchronous belt to be tested; 9. Sensor receiver; 10. Connecting frame; 11. Connecting part; 12. Connecting sleeve; 13. Abutment post; 14. Extension shaft; 15. First pulley; 16. First transmission belt; 17. Guide rail; 18. Bogie; 19. Counterweight plate; 20. Flexible connector; 21. Steering wheel; 22. Second pulley; 23. Movable hole; 24. Movable groove; 25. Guide shell; 26. Drive hole; 27. Stroke block; 28. Stroke groove; 29. ​​Mounting groove; 30. Second elastic element; 34. Cooling equipment. Detailed Implementation

[0021] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0022] refer to Figures 1 to 7 A bicycle timing belt fatigue testing device includes a test bench 1, a simulation assembly and a control device 2 set on the test bench 1. The simulation assembly includes a timing belt drive device 3, a pulley offset device 4, a timing belt load device 5, a timing belt tension device 6 and a speed measuring device 7. Each device of the simulation assembly is connected to and controlled by the control device 2. The control device 2 has a timing module, a display module and a control processing module. The synchronous belt drive device 3 includes a driving pulley 31, a driven pulley 32, and a rotary motor 33. The inner diameter of the driving pulley 31 is larger than that of the driven pulley 32. The synchronous belt 8 to be tested is sleeved between the driving pulley 31 and the driven pulley 32. The rotary motor 33 is electrically connected to the control device 2. The driving pulley 31 is provided with a sensing end. A sensor receiver 9 is provided on the test platform 1 near the driving pulley 31. The sensor receiver 9 can be a metal sensor, and the sensing end is a metal sensor. The sensor receiver 9 and the sensing end are inductively coupled. The sensor receiver 9 is electrically connected to the control device 2.

[0023] The pulley offset device 4 includes a centering shaft 41, a drive disk 42, a guide disk 43, a first elastic element 44, and an adjusting element 45. A connecting frame 10 is provided on the test bench 1. The centering shaft 41 is rotatably connected to the connecting frame 10 and connected to the movable part of the rotary motor 33. The guide disk 43 and the drive disk 42 are spaced apart. The drive pulley 31 is located between the guide disk 43 and the drive disk 42. The drive pulley 31 is sleeved with the centering shaft 41. The drive disk 42 is connected to the centering shaft 41. The drive disk 42 is symmetrically provided with two connecting parts 11, both of which are spaced apart from the centering shaft 41. The drive pulley 31 is hollow inside and is provided with a connecting sleeve 12 for the connecting parts 11 to engage with, so as to guide the drive pulley 31 to translate and swing along the axial direction of the centering shaft 41 between the guide disk 43 and the drive disk 42. When the rotary motor 33 is started, the movable part of the rotary motor 33 drives the drive disk 42 to rotate. The drive disk 42 drives the drive pulley 31 to rotate synchronously through the connecting parts 11.

[0024] A stop post 13 is provided on the side wall of the drive pulley 31 near the guide disk 43. The stop post 13 is a sensing end. The first elastic element 44 acts between the drive disk 42 and the drive pulley 31, causing the drive pulley 31 to move closer to the guide disk 43 along the axial direction of the centering shaft 41, keeping the stop post 13 in contact with the guide disk 43. The upper part of the guide disk 43 is movably connected to the connecting frame 10. A hinge seat is provided between the connecting frame 10 and the upper part of the guide disk 43, so that the guide disk 43... The hinged movement is within the connecting frame 10, and the middle of the guide plate 43 is through to allow the centering shaft 41 to move relative to it. The adjusting member 45 is threaded onto the connecting frame 10. The adjusting member 45 passes through the end of the connecting frame 10 and engages with the lower part of the guide plate 43. By screwing in or out the adjusting member 45, the face of the adjusting member 45 screwed into the end of the connecting frame 10 abuts against the guide plate 43, thereby driving the drive pulley 31 to rotate in the initial position or move back and forth and rotate in the swing position. When the length of the end of the adjusting member 45 screwed into the connecting frame 10 is equal to the distance between the upper part of the guide plate 43 and the inner wall of the connecting frame 10, the lower part of the guide plate 43 is held in the initial position under the support of the adjusting member 45, so as to keep the guide plate 43 parallel to the opposite side of the drive pulley 31. The drive pulley 31 is positioned and rotated on the centering shaft 41 to simulate the operation of the synchronous belt 8 under test on a flat road surface. When the length of the end of the adjusting member 45 screwed into the connecting frame 10 is greater than the distance between the upper part of the guide plate 43 and the inner wall of the connecting frame 10, the lower part of the guide plate 43 is held in a swing position under the support of the adjusting member 45, so as to maintain the plane on which the guide plate 43 and the opposite side of the drive pulley 31 intersect. Under the action of the first elastic member 44, the abutting column always abuts against the guide plate 43, and the drive pulley 31 moves back and forth and rotates axially on the centering shaft 41 to simulate the running condition of the synchronous belt 8 under test being driven by the drive pulley 31 and deviating on bumpy road conditions.

[0025] The synchronous belt load device 5 includes an adjustment frame 51 and a resistance device 52 mounted on the adjustment frame 51. The adjustment frame 51 is rotatably connected to an extension shaft 14. The driven pulley 32 is connected to the first end of the extension shaft 14. The resistance device 52 can be a rotary damper, a resistance motor, or a reduction gearbox. Both the movable end of the resistance device 52 and the second end of the extension shaft 14 are provided with first pulleys 15. A first transmission belt 16 is sleeved between the two first pulleys 15, meshing with the first pulleys 15 to achieve synchronous belt transmission between the driven pulley 32 and the resistance device 52. Preferably, the first transmission belt 16 and the first pulleys 15 can also be a chain drive. The resistance device 52 applies resistance to the driven pulley 32 to simulate the operation of the synchronous belt 8 under different loads on level or bumpy roads. The testing device also includes a cooling device 34, which uses water cooling to prevent the resistance device 52 from overheating due to overload. This is existing technology and will not be described in detail here. The test bench 1 is provided with a guide rail 17 for the sliding connection of the adjustment frame 51. A bogie 18 is provided at the end of the guide rail 17 away from the drive pulley 31. A counterweight plate 19 is suspended on the bogie 18. A flexible connector 20 is connected between the counterweight plate 19 and the adjustment frame 51. The bogie 18 is rotatably connected to a steering wheel 21 that abuts against the flexible connector 20. The counterweight plate 19 can be loaded with a weight of corresponding weight according to the tension requirements of the synchronous belt 8 to be tested, so that the driven pulley 32 is pulled horizontally away from the drive pulley 31 through the flexible connector 20, so that the synchronous belt 8 to be tested is tensioned between the drive pulley 31 and the driven pulley 32.

[0026] The synchronous belt tensioning device 6 includes a lifting member 61 and a transmission mechanism 62. The transmission mechanism 62 is linked to the movable part of the rotary motor 33. The test platform 1 has a through movable groove 24 for the lifting member 61 to slide and connect, guiding the lifting member 61 to push out and retract. The lifting member 61 is movably connected between the corresponding driving pulley 31 and driven pulley 32 of the test platform 1. The transmission mechanism 62 includes a power shaft 621, a second transmission belt 622 and a drive cam 623. The power shaft 621 is rotatably connected to the bottom of the test platform 1. The first end of the power shaft 621 and the movable part of the rotary motor 33 are both provided with second pulleys 22. The second transmission belt 622 is sleeved between the two second pulleys 22 and meshes with the second pulleys 22 to realize synchronous belt transmission between the power shaft 621 and the rotary motor 33. Preferably, the second transmission belt 622 and the second pulleys 22 can also be a chain drive. The test bench 1 has a through hole 23 for the second transmission belt 622 to move. The drive cam 623 is an eccentric wheel and is detachably connected to the second end of the power shaft 621. A guide shell 25 is provided at the bottom of the test bench 1. The inner cavity of the guide shell 25 is connected to the movable groove 24. The lower ends of the drive cam 623 and the lifting member 61 are both movable in the inner cavity of the guide shell 25. The lower end of the lifting member 61 has a through hole 26. The lower end of the lifting member 61 includes a stroke block 27. The drive hole 26 passes through the stroke block 27. The inner cavity of block 27 and guide shell 25 includes a connected travel groove 28 and mounting groove 29. The travel block 27 is slidably connected in the travel groove 28. The mounting groove 29 is located above the travel groove 28 and is provided with a second elastic member 30. The second elastic member 30 acts between the mounting groove 29 and the travel block 27. The top inner wall of the mounting groove 29 is formed with the bottom inner wall of the test bench 1. The bottom inner wall of the test bench 1 and the opposite side of the travel block 27 are provided with protrusions for the second elastic member 30 to be fitted.

[0027] When the rotary motor 33 starts, the rotary motor 33 drives the power shaft 621 to rotate through the second transmission belt 622. The power shaft 621 drives the drive cam 623 to rotate. The upper part of the lifting member 61 is an I-beam wheel. Under the action of the second elastic member 30, the stroke block 27 tends to move away from the I-beam wheel. The inner wall of the drive hole 26 abuts against the outer wall of the drive cam 623. Using the eccentric wheel transmission, the drive cam 623 drives the stroke block 27 to move up and down repeatedly in the vertical direction. When the lifting member 61 is pushed out, it abuts against the synchronous belt 8 under test, causing it to stretch and deform, thereby simulating the situation where the synchronous belt 8 under test is stretched by multiple collisions with obstacles on a horizontal or bumpy road.

[0028] The present invention drives the active pulley 31 to rotate via a rotary motor 33 and drives the driven pulley 32 to rotate via the synchronous belt 8 under test. The synchronous belt load device 5 applies resistance to the rotation of the driven pulley 32 to simulate the load operation of the synchronous belt 8 under test when a bicycle is in motion. The pulley offset device 4 is linked with the movable part of the rotary motor 33 to make the drive pulley 31 rotate in the initial position to simulate the operation of the synchronous belt 8 under test on a horizontal road, or to make the drive pulley 31 swing back and forth and rotate in the swing position to simulate the operation of the synchronous belt 8 under test on a bumpy road. During this process, the synchronous belt tensioning device 6 is linked with the moving part of the rotary motor 33 through the transmission mechanism 62, so that the lifting member 61 lifts the synchronous belt 8 to be tested to simulate the running condition of the synchronous belt 8 being hit by an obstacle. It can simulate the tensile fatigue test of the synchronous belt 8 under level or bumpy road conditions as needed, which increases the accuracy of the test results.

[0029] This invention uses a device to perform multiple road condition tests, and the pulley offset device 4 and the synchronous belt tensioning device 6 can be linked by a rotary motor 33, which reduces the cost of the device, has good applicability, and is convenient to use and operate.

[0030] The speed measuring device 7 includes a first speed sensor 71 and a second speed sensor 72. The control device 2 controls the acquisition of data by the first speed sensor 71 and the second speed sensor 72. The first speed sensor is installed on the connecting frame 10 at the movable part corresponding to the rotary motor 33 to detect the rotational speed of the driving pulley 31. The second speed sensor is installed on the moving frame at the extension shaft 14 to detect the rotational speed of the driven pulley 32. The first speed sensor 71 and the second speed sensor 72 feed back the sensed speed data to the control processing module of the control device 2, and after data processing, the data is displayed on the display module for direct observation of the rotational speeds of the driving pulley 31 and the driven pulley 32.

[0031] A fatigue testing method for bicycle timing belts, using the testing device described above to perform fatigue testing on the timing belt 8 under test, includes the following steps: S1. The synchronous belt 8 to be tested is fitted onto the driving pulley 31 and the driven pulley 32. The simulated mileage of the synchronous belt 8 to be tested is preset by the control device 2. Preferably, the preset value is the number of rotations required by the driving pulley 31 when the synchronous belt 8 to be tested reaches the simulated mileage. S2. Move the synchronous belt load device 5 to the test bench 1 and adjust the distance between the driving pulley 31 and the driven pulley 32 so that the synchronous belt 8 under test is tensioned between the driving pulley 31 and the driven pulley 32. S3. According to the requirements, the drive pulley 31 is switched to the initial position or the swing position by the pulley offset device 4. S4. Start the rotary motor 33, so that the active pulley 31 rotates and drives the driven pulley 32 to rotate synchronously through the synchronous belt under test 8. The sensor receiver 9 records the number of rotations of the active pulley 31 and feeds it back to the control processing module of the control device 2. After data processing, the data is fed back to the display module, so that the real-time movement distance of the synchronous belt under test 8 can be directly observed. S5. The load simulation of the load operation of the synchronous belt 8 under test is achieved by providing resistance to the rotation of the driven pulley 32 through the synchronous belt load device 5. S6. The timing belt tensioning device 6 is pressed against the timing belt 8 to be tested, causing it to stretch and deform during operation, so as to simulate the situation where the timing belt 8 to be tested collides with obstacles multiple times during operation. S7. The control device 2 has a timing module to control the rotary motor 33 to start and stop at intervals. The stop time of the rotary motor 33 is set to 3s, and the start time of the rotary motor 33 is set to 10s. The test is carried out in a continuous cycle. The control processing module of the control device 2 analyzes the mileage of the synchronous belt 8 under test and the preset simulated mileage. When the real-time mileage of the synchronous belt 8 under test reaches the preset simulated mileage, the control device 2 stops the rotary motor 33, takes out the synchronous belt 8 under test and observes the damage on its surface, thereby obtaining the test result of the fatigue performance of the synchronous belt 8 under test.

[0032] Preferably, the testing device can also use data comparison to obtain the fatigue performance test results of the timing belt 8 under test. In a bicycle, the driving pulley 31 is a larger diameter driving pulley, and the driven pulley 32 is a smaller diameter driven pulley. The driving pulley 31 drives the driven pulley 32 to rotate synchronously through the timing belt 8 under test. The power for the rotation of the driven pulley 32 is transmitted by the timing belt 8 under test. Under ideal conditions, the linear velocities of the driving pulley 31 and the driven pulley 32 are equal. The acceleration of the bicycle is simulated by driving the driving pulley 31 to rotate and providing power output. The number of teeth on the outer diameter of the driving pulley 31 is Z1, and the number of teeth on the outer diameter of the driven pulley 32 is Z2. The constant transmission ratio of the synchronous belt 8 under ideal conditions is obtained as i1 = Z1 / Z2. The speed measuring device 7 detects the rotational speed of the driving pulley 31 and the driven pulley 32 respectively. The rotational speed of the driving pulley 31 is a, and the rotational speed of the driven pulley 32 is b. If the synchronous belt 8 under test suffers fatigue wear, resulting in poor driving effect on the driven pulley 32 and affecting the rotational speed b of the driven pulley 32, the running stability of the synchronous belt 8 under test can be judged based on whether the speed ratio between the rotational speed b of the driven pulley 32 and the rotational speed a of the driving pulley 31 satisfies the constant transmission ratio i1. Thus, a more accurate test result of the fatigue performance of the synchronous belt 8 under test can be obtained.

[0033] Of course, the above are just typical examples of the present invention. In addition, the present invention may have many other specific embodiments. All technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection claimed by the present invention.

Claims

1. A fatigue testing device for bicycle timing belts, characterized in that: The system includes a test bench (1), a simulation assembly and a control device (2) mounted on the test bench (1). The simulation assembly includes a synchronous belt drive device (3), a pulley offset device (4), a synchronous belt load device (5), a synchronous belt tension device (6), and a speed measuring device (7). Each device of the simulation assembly is connected to and controlled by the control device (2). The control device (2) has a timing module, a display module, and a control processing module. The synchronous belt drive device (3) includes a driving pulley (31), a driven pulley (32) and a rotary motor (33). The synchronous belt (8) to be tested is sleeved between the driving pulley (31) and the driven pulley (32). The rotary motor (33) is electrically connected to the control device (2). The driving pulley (31) is provided with a sensing end. A sensor receiver (9) that senses and cooperates with the sensing end is provided on the test bench (1) near the driving pulley (31). The sensor receiver (9) is electrically connected to the control device (2). The pulley offset device (4) is provided on the movable part of the rotary motor (33) to drive the drive pulley (31) to rotate in the initial position or to move back and forth and rotate in the swing position; The synchronous belt load device (5) is movably connected to the test bench (1), and the synchronous belt load device (5) is connected to the driven pulley (32) to apply resistance to the driven pulley (32) and to make the synchronous belt (8) under test tensioned between the driving pulley (31) and the driven pulley (32); The synchronous belt stretching device (6) includes a lifting member (61) and a transmission mechanism (62). The lifting member (61) is movably connected to the test bench (1) between the driving pulley (31) and the driven pulley (32). The transmission mechanism (62) is linked with the moving part of the rotary motor (33) to drive the lifting member (61) to move up and down and drive the synchronous belt (8) to be tested to stretch and deform. The speed measuring device (7) includes a first speed sensor (71) and a second speed sensor (72) for detecting the rotational speeds of the driving pulley (31) and the driven pulley (32) respectively. The control device (2) controls the acquisition of the first speed sensor (71) and the second speed sensor (72). The inner diameter of the driving pulley (31) is larger than the inner diameter of the driven pulley (32); The pulley offset device (4) includes a centering shaft (41) and a drive disk (42). A connecting frame (10) is provided on the test bench (1). The centering shaft (41) is rotatably connected to the connecting frame (10) and connected to the movable part of the rotary motor (33). The drive pulley (31) is sleeved with the centering shaft (41). The drive disk (42) is connected to the centering shaft (41). The drive disk (42) is provided with at least one connecting part (11) spaced apart from the centering shaft (41). The drive pulley (31) is hollow inside and is provided with a connecting sleeve (12) for the connecting part (11) to be sleeved with. The pulley offset device (4) further includes a guide plate (43), a first elastic element (44), and an adjusting element (45). The guide plate (43) is spaced apart from the drive plate (42). The drive pulley (31) is located between the guide plate (43) and the drive plate (42). The drive pulley (31) has an abutment post (13) near the side wall of the guide plate (43). The first elastic element (44) acts between the drive plate (42) and the drive pulley (31), causing the drive pulley (31) to move closer to the guide plate (43) along the axial direction of the centering shaft (41). The abutment post (13) abuts against the guide plate (43). The upper part of the guide plate (43) is movably connected to the connecting frame (10), and the middle part of the guide plate (43) is through to allow the centering shaft (41) to move relative to it. The adjusting member (45) is threadedly connected to the connecting frame (10), and the adjusting member (45) passes through the end of the connecting frame (10) and cooperates with the lower part of the guide plate (43).

2. The bicycle timing belt fatigue testing device according to claim 1, characterized in that: The synchronous belt load device (5) includes an adjustment frame (51) and a resistance device (52) disposed on the adjustment frame (51). The adjustment frame (51) is rotatably connected to an extension shaft (14). The driven pulley (32) is connected to the first end of the extension shaft (14). The movable end of the resistance device (52) and the second end of the extension shaft (14) are both provided with first pulleys (15). A first transmission belt (16) is sleeved between the two first pulleys (15). The first transmission belt (16) meshes with the first pulleys (15).

3. The bicycle timing belt fatigue testing device according to claim 2, characterized in that: The resistance device (52) may be a rotary damper, a resistance motor, or a reduction gearbox.

4. The bicycle timing belt fatigue testing device according to claim 2, characterized in that: The test bench (1) is provided with a guide rail (17) for the adjustment frame (51) to slide and connect. A bogie (18) is provided at the end of the guide rail (17) away from the drive pulley (31). A counterweight plate (19) is suspended on the bogie (18). A flexible connector (20) is connected between the counterweight plate (19) and the adjustment frame (51). The bogie (18) is rotatably connected with a steering wheel (21) that abuts against the flexible connector (20).

5. The bicycle timing belt fatigue testing device according to claim 1, characterized in that: The transmission mechanism (62) includes a power shaft (621), a second transmission belt (622), and a drive cam (623). The power shaft (621) is rotatably connected to the bottom of the test bench (1). A second pulley (22) is provided at the first end of the power shaft (621) and the movable part of the rotary motor (33). The second transmission belt (622) is sleeved between the two second pulleys (22), and the second transmission belt (622) meshes with the second pulleys (22). The test bench (1) has a through hole (23) for the second transmission belt (622) to move. The drive cam (623) 623) is an eccentric wheel and is detachably connected to the second end of the power shaft (621). The test platform (1) has a movable groove (24) through which the lifting member (61) slides. The bottom of the test platform (1) is provided with a guide shell (25). The inner cavity of the guide shell (25) is connected to the movable groove (24). The lower ends of the drive cam (623) and the lifting member (61) are both movable in the inner cavity of the guide shell (25). The lower end of the lifting member (61) has a drive hole (26) through it. The inner wall of the drive hole (26) abuts against the outer wall of the drive cam (623).

6. The bicycle timing belt fatigue testing device according to claim 5, characterized in that: The lower end of the lifting member (61) includes a stroke block (27), the driving hole (26) passes through the stroke block (27), the inner cavity of the guide shell (25) includes a connected stroke groove (28) and a mounting groove (29), the stroke block (27) is slidably connected in the stroke groove (28), the mounting groove (29) is located above the stroke groove (28) and is provided with a second elastic member (30), the second elastic member (30) acts between the mounting groove (29) and the stroke block (27).

7. A method for fatigue testing of bicycle timing belts, characterized in that: The fatigue test of the bicycle timing belt (8) under test is performed using the bicycle timing belt fatigue testing device as described in any one of claims 1 to 6, comprising the following steps: S1. Place the synchronous belt (8) to be tested onto the driving pulley (31) and the driven pulley (32), and preset the simulated mileage of the synchronous belt (8) to be tested through the control device (2); S2. Move the synchronous belt load device (5) to the test bench (1) and adjust the distance between the driving pulley (31) and the driven pulley (32) so that the synchronous belt (8) to be tested is tensioned between the driving pulley (31) and the driven pulley (32). S3. According to the requirements, the drive pulley (31) is switched to the initial position or the swing position by the pulley offset device (4); S4. Start the rotary motor (33) so that the active pulley (31) rotates and drives the driven pulley (32) to rotate synchronously through the synchronous belt (8) under test. The sensor receiver (9) records the number of rotations of the active pulley (31) and feeds it back to the control processing module of the control device (2). After data processing, the data is fed back to the display module, so as to directly observe the real-time movement distance of the synchronous belt (8) under test. S5. By using the synchronous belt load device (5) to provide resistance to the rotation of the driven pulley (32), the load simulation is performed to simulate the load operation of the synchronous belt (8) under test. S6. The synchronous belt stretching device (6) is used to abut against the synchronous belt to be tested (8) to stretch and deform it during operation; S7. The control device (2) has a timing module to control the rotary motor (33) to start and stop at intervals. The stopping time of the rotary motor (33) is set to 3s, and the starting time of the rotary motor (33) is set to 10s. The test is continuously cycled in this way. The control processing module of the control device (2) performs data analysis on the mileage of the synchronous belt (8) under test and the preset simulated mileage. When the real-time mileage of the synchronous belt (8) under test reaches the preset simulated mileage, the control device (2) stops the rotary motor (33) and takes out the synchronous belt (8) under test to observe the damage on its surface.

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