Automatic transmission shift actuator test device and test method

Abstract

The present invention discloses a test device and a test method for an automatic transmission shift actuator, wherein the device comprises: a shift motor, a gear set, a transmission shaft, a space cam, a cam groove, a compression spring set, a constant force spring, a synchronous baffle, a slider, a shift fork, and a worm gear box, etc. The present invention effectively replaces the complex shift resistance load by equivalent devices such as compression springs, thereby realizing an accurate simulation of the change in the shift resistance load. The present invention also provides a control method for the test device, including designing a resistance superposition model at the shift fork, detecting the displacement of the synchronous baffle by a pressure tester and feeding it back to the shift motor control module, thereby achieving a staged control simulation, and realizing effective control of the automatic transmission shift actuator device. The present automatic transmission shift actuator test device is a detachable test device, which has the advantages of easy installation, low cost, and convenient testing.

Description

Technical Field

[0001] The invention relates to the field of an automobile automatic transmission shift actuator, and in particular to an automatic transmission shift actuator test device and a test method. Background Art

[0002] The electric-driven shift actuator is a key component in the automobile transmission system. Its stability performance affects the safety of the vehicle driver and is also a very important performance indicator for evaluating a vehicle. Shift force is particularly important as one of the indicators for evaluating the performance of an automatic transmission. Conducting simulation tests on its shifting process is an important part of design and development. The key point is how to achieve accurate simulation of different shifting resistance loads. The existing constant resistance test system cannot achieve variable load simulation. Considering factors such as cost and test convenience, a test system using a multi-spring combination was invented, which can achieve accurate simulation of the shifting process load. It is low-cost, simple to manufacture and easy to operate, and has good engineering application prospects. Summary of the invention

[0003] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0004] A test device and test method for an automatic transmission shift actuator, characterized in that the device comprises: a shift motor, a gear set, a transmission shaft, a space cam, a cam groove, a shift fork and a worm gear box; the shift motor is directly connected to the upper gear of the gear set after the motor shaft is decelerated through the worm gear box, one end of the transmission shaft is directly connected to the lower gear of the gear set, and the other end is fixed to the space cam, and the shift fork is embedded in the cam groove on the space cam through a connecting rod and moves along the groove track.

[0005] The slide rail is fixed on the base plate, and a spring baffle A and a spring baffle B are respectively installed on both sides of the slide rail; the constant force spring is fixed to the spring baffle B through a constant force spring support, and the compression spring group and the magnetic spring are fixed to the spring baffle A through a compression spring support; the slider cooperates with the slide rail and slides on its track; the synchronous baffle is installed on the slider, and a pressure sensor is installed on one side of the synchronous baffle, and a boss that cooperates with the compression spring group is installed on the other side; the pressure sensor is connected to the pressure tester through a signal line, and the pressure tester is fixed on the mounting baffle.

[0006] Furthermore, the pressure sensor is a sensor with high precision and fast response.

[0007] Furthermore, the shift motor is a high-power, high-torque, small-volume motor.

[0008] Furthermore, the shift motor is fixedly mounted on a motor support, the transmission shaft is fixedly mounted on a cam mechanism support, and the motor support is spatially distributed in a stepped decreasing manner with the cam mechanism support and the base plate; the upper gear and the lower gear of the gear set cooperate with each other, and the shift motor and the transmission shaft are distributed at a 90° angle.

[0009] Furthermore, the slide rail is a T-shaped guide rail with a protrusion in the middle of the slide rail. The upper part of the slider is fixedly installed with a synchronous baffle, and the lower part cooperates with the slide rail and the I-shaped notch of the bottom plate; the middle part of the slider includes a slider inner cavity and a pull rod fixed to the slider through a rotating sheath, and a rotating spring is installed on the rotating sheath. When the pull rod is in a horizontal state, the spring force is 0; the pull rod can be rotated through the rotating sheath, and the other end of the pull rod is hook-shaped and extends into the hole at one end of the constant force spring. A pulley is installed near the hole of the constant force spring at one end of the slider.

[0010] Furthermore, the constant force spring, magnetic spring and compression spring are preset springs with different parameters.

[0011] Furthermore, the profile of the cam groove is a first gear, neutral gear and second gear stroke profile designed according to the gear positions; the torque of the shift motor after starting is input to the worm gear box through the motor shaft, and the gear group is driven to rotate through the shaft, and the lower gear of the gear group drives the spatial cam to rotate coaxially, and the shift fork moves left and right along the profile of the cam groove due to the rotation of the spatial cam, and when it moves in the direction of the synchronous baffle, it will drive the baffle to move.

[0012] Furthermore, the synchronous baffle can drive the slider to move along the direction of the slide rail through a shift fork, and the boss is a group of bosses distributed in sequence from top to bottom, and the length of the protruding part of the boss is determined by the resistance distribution during design and corresponds one-to-one with the compression spring group and the magnetic spring; the boss and the compression spring support are detachable and can be installed with different spring groups and bosses; when the slider moves toward the spring baffle A, the hook end of the pull rod will drive the constant force spring to generate a fixed resistance after a certain displacement, and after the slider passes the protrusion, the pull rod rotates counterclockwise along the rotating sheath as it contacts the protrusion, and then the hook end of the pull rod moves downward and disconnects from the constant force spring due to the action of the pulley.

[0013] Furthermore, the control method preparation step includes:

[0014] 1) Calculate the shift force and displacement distance of the shift fork required by the automatic transmission during the actual shifting process, and set different groups of compression springs, magnetic springs and constant force springs to simulate the shift force when different gears and vehicle speeds change;

[0015] 2) Install the set compression spring group, magnetic spring and constant force spring on the compression spring support and the constant force spring support, and push the slider and its synchronous baffle to the initial end of the predetermined fork displacement stroke;

[0016] 3) Setting the position of the constant force spring, wherein the hook end of the constant force spring needs to contact the pull rod to generate a constant resistance after the slider reaches a predetermined position;

[0017] 4) Set the controller program for controlling the shift motor and match it with the shift resistance set in the test to control the operating speed of the shift motor.

[0018] Furthermore, the control method operation steps include:

[0019] 5) Start the controller program, the shift motor starts forward, and after the worm gear box decelerates and increases torque, it drives the upper gear of the gear set to rotate clockwise, while the lower gear drives the transmission shaft and the space cam to rotate counterclockwise;

[0020] 6) At this time, the connection of the shift fork is located at the first gear contour of the cam groove. As the transmission shaft rotates counterclockwise, the shift fork begins to contact the pressure sensor due to the change in the contour of the cam groove. The pressure sensor transmits the pressure signal to the pressure tester through the signal line. The shift fork drives the synchronous baffle and the slider to move along the slide rail away from the shift motor.

[0021] 7) During the displacement of the synchronous baffle, due to the different lengths of the bosses, the bosses sequentially contact the compression spring group and the magnetic spring in different displacement strokes to generate resistance, thereby achieving the effect of simulating the change in the size of the resistance source of the automatic transmission in different strokes;

[0022] 8) During the displacement of the slider, the pull rod contacts the constant force spring after reaching the set stroke, generating resistance. After the slider continues to move for a certain stroke, the right end of the pull rod contacts the protrusion. Under the action of the protrusion, the pull rod rotates counterclockwise along the rotating sheath. Under the inclination of the pull rod, the constant force spring stops generating resistance by decoupling from the pull rod through the pulley. This resistance is used to simulate the sudden appearance and disappearance of some resistance sources in the synchronization process of the automatic transmission.

[0023] 9) After the displacement distance of the shift fork reaches the set value, the shift motor stops running, and the pressure tester records the pressure change value of the whole process. After the recording is completed, the shift motor runs in the reverse direction, the shift fork moves toward the shift motor, and the synchronous baffle moves toward the shift motor under the action of the compression spring group and the magnetic spring until the compression spring group recovers its deformation, and all components return to their original positions;

[0024] 10) Testing completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following is a brief description of the contents expressed in the drawings of the present invention and the marks in the drawings.

[0026] Figure 1 It is a schematic diagram of the main structure of the present invention.

[0027] Figure 2 A top view of the gantry device.

[0028] Figure 3 This is the plan view of the slide rail slider part.

[0029] Figure 4 Schematic diagram of the load force at the fork.

[0030] Figure markings: 1. shift motor; 2. gear set; 3. transmission shaft; 4. space cam; 5. cam groove; 6. shift fork; 7. pressure sensor; 8. boss; 9. compression spring group; 10. magnetic spring; 11. spring baffle A; 12. spring baffle B; 13. constant force spring; 14. pulley; 15. pull rod; 16. bottom plate; 17. slider; 18. synchronous baffle; 19. slide rail; 20. motor support; 21. cam mechanism support; 22. signal line; 23. pressure tester; 24. mounting baffle; 25. compression spring support; 26. rotating sheath; 27. protrusion; 28. slider cavity; 29. ​​worm gear box; 30. constant force spring support. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0032] In the description of the present application, the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In the description of this application, unless otherwise clearly specified and limited, the terms "installation", "fitting", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0034] Furthermore, in the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments.

[0035] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0036] See also Figure 1 As shown, a bench test system for a shift actuator and a control method thereof are characterized in that the device comprises: a shift motor 1, a gear set 2, a transmission shaft 3, a space cam 4, a cam groove 5, a shift fork 6, a pressure sensor 7, a compression spring set 9, a magnetic spring 10, a constant force spring 13, a slider 17, a synchronous baffle 18, a slide rail 19, a motor support 20 and a worm gear box 29; the shift motor 1 is directly connected to the upper gear of the gear set 2 after the motor shaft is decelerated through the worm gear box 29, one end of the transmission shaft 3 is directly connected to the lower gear of the gear set 2, and the other end is fixedly connected to the space cam 4, the shift fork 6 is embedded in the cam groove 5 on the space cam 4 through a connecting rod and moves along the groove track; the shift motor 1 is a high-power, high-torque and small-volume motor; the slide rail 19 is fixed Fixed on the bottom plate 16, a spring baffle A11 and a spring baffle B12 are respectively installed on both sides of the slide rail 19; the constant force spring 13 is fixed on the spring baffle B12 through a constant force spring support 30, and the compression spring group 9 and the magnetic spring 10 are fixed on the spring baffle A11 through a compression spring support 25; the slider 17 cooperates with the slide rail 19 and slides on its track; the synchronous baffle 18 is installed on the slider 17, and a pressure sensor 7 is installed on one side of the synchronous baffle 18, and a boss 8 that cooperates with the compression spring group 9 and the magnetic spring 10 is installed on the other side; the pressure sensor 7 is a sensor with high precision and fast response; the pressure sensor 7 is connected to the pressure tester 23 through a signal line 22, and the pressure tester 23 is fixed on the mounting baffle 24.

[0037] like Figure 2 , 3 As shown, the shift motor 1 is fixedly mounted on the motor support 20, and the transmission shaft 3 is fixedly mounted on the cam mechanism support 21. The motor support 20 is spatially distributed in a stepped decreasing manner with the cam mechanism support 21 and the base plate 16; the upper gear and the lower gear of the gear set 2 cooperate with each other, and the shift motor 1 and the transmission shaft 3 are distributed at a 90° angle.

[0038] In this example, the slide rail 19 is a T-shaped guide rail with a protrusion 27 in the middle of the slide rail 19. The upper part of the slider 17 is fixedly mounted with the synchronous baffle 18, and the lower part cooperates with the slide rail 19 and the I-shaped notch of the bottom plate 16; the middle part of the slider 17 includes a slider inner cavity 28 and a pull rod 15 fixed to the slider 17 through a rotating sheath 26, and a rotating spring is installed on the rotating sheath 26. When the pull rod 15 is in a horizontal state, the spring force is 0; the pull rod 15 can be rotated through the rotating sheath 26, and the other end of the pull rod 15 is hook-shaped and extends into the hole at one end of the constant force spring 13. The hole of the constant force spring 13 is close to the end of the slider 17 and a pulley 14 is installed.

[0039] In this example, the profile of the cam groove 5 is a first gear, neutral gear and second gear travel profile designed according to the gear position; the torque of the shift motor 1 after starting is input to the worm gear box 29 through the motor shaft, and the gear set 2 is driven to rotate through the shaft. The rotation of the lower gear of the gear set 2 drives the spatial cam 4 to rotate coaxially. The shift fork 6 moves left and right along the profile of the cam groove 5 due to the rotation of the spatial cam 4, and when it moves in the direction of the synchronous baffle 18, it will drive the baffle to move.

[0040] In this example, the synchronous baffle 18 can drive the slider 17 to move along the slide rail 19 through the fork 6. The boss 8 is a group of bosses distributed in sequence from top to bottom. The length of the protruding part of the boss 8 is determined by the resistance distribution during design and corresponds one-to-one with the compression spring group 9; the boss 8 and the compression spring support 25 are detachable and can be installed with different spring groups and bosses; when the slider 17 moves toward the spring baffle A11, the hook end of the pull rod 15 will drive the constant force spring 13 to generate a fixed resistance after a certain displacement. After the slider 17 passes the protrusion 27, the pull rod 15 rotates counterclockwise along the rotating sheath 26 as it contacts the protrusion 27, and then the hook end of the pull rod 15 moves downward and disconnects from the constant force spring 13 due to the action of the pulley 14.

[0041] like Figure 4 As shown, in this example, when the shift fork 6 is located at the first position of the groove track of the cam groove 5, x is the coordinate origin 0, and the direction along the coordinate origin toward the spring baffle A11 is the positive direction of the x-axis.

[0042] In the above coordinate system, the superposition model of the resistance at the fork is:

[0043]

[0044] Wherein, x is the displacement distance of the shift fork 6, and its value range is related to the automatic transmission under study, which is approximately 0 to 20 mm, wherein the sizes of x1, x2, x3, x4 and x5 are also related to the automatic transmission under study; F(x) is the total spring superposition force; μ is the sliding friction coefficient; FN is the gravity of the synchronous baffle 18 and its affiliated mechanisms; k1 is the coefficient of the constant force spring 13; N1 is the total number of constant force spring 13 loads; k2 is the coefficient of compression spring group A; d2 is the distance from the origin to the end of the compression spring group A close to the boss 8; k3 is the coefficient of the compression spring group B; d3 is the distance from the origin to the end of the compression spring group B close to the boss 8; k4 is the coefficient of the magnetic spring 10; N2 is the total number of magnetic spring 10 loads.

[0045] A control method for a shift actuator bench test system proposed by the present invention is as follows.

[0046] The control method preparation step comprises:

[0047] 1) Calculate the shift force required by the automatic transmission during the actual shifting process and the displacement distance of the shift fork 6, and set different groups of compression spring groups 9, magnetic springs 10 and constant force springs 13 to simulate the shift force when different gear positions and vehicle speeds change;

[0048] 2) Install the set compression spring group 9, magnetic spring 10 and constant force spring 13 on the compression spring support 25 and the constant force spring support 30, and push the slider 17 and its synchronous baffle 18 to the initial end of the predetermined fork displacement stroke;

[0049] 3) Setting the position of the constant force spring 13, the hook end of the constant force spring 13 needs to contact the pull rod 15 to generate a constant resistance after the slider 17 reaches the predetermined position;

[0050] 4) Setting a controller program for controlling the shift motor 1 and matching it with the shift resistance set in the test to control the running speed of the shift motor 1 .

[0051] After completing the preparation steps, the control test of the automatic transmission upshift test is carried out. First, the controller program is started. After receiving the upshift command, the shift motor 1 starts forward and drives the upper gear of the gear set 2 to rotate clockwise after deceleration and torque increase through the worm gear box 29. At the same time, the lower gear drives the transmission shaft 3 together with the spatial cam 4 to rotate counterclockwise. At this time, the connection point of the shift fork 6 is located at the first gear contour of the cam groove 5, that is, at the coordinate origin 0. As the transmission shaft 3 rotates counterclockwise, the shift fork 6 starts to contact the pressure sensor 7 due to the change in the contour of the cam groove 5. The pressure sensor 7 transmits the pressure signal to the pressure tester 23 through the signal line 22. The pressure tester 23 starts to record data and the timer starts timing.

[0052] After time t1, friction resistance is generated between the slider 17 and the slide rail 19, and static friction is changed into dynamic friction, and the magnitude of F(x) changes from the maximum static friction F3 to the sliding friction F1 at time t1; then the shift fork 6 drives the synchronous baffle 18 together with the slider 17 to move along the slide rail 19 away from the shift motor 1; during the displacement process of the synchronous baffle 18 driven by the shift fork 6, due to the different lengths of the boss 8, the boss 8 sequentially contacts the compression spring group 9 and the magnetic spring 10 in different displacement strokes to generate resistance opposite to the displacement direction, thereby achieving the effect of simulating the change in the size of the resistance source of the automatic transmission at different strokes, and the resistance size is the size value calculated in the preparation stage.

[0053] After time t2, during the advancement and displacement of the slider 17 by the synchronous baffle 18, the pull rod 15 contacts the constant force spring 13 after reaching the set stroke to generate resistance, and the magnitude of F(x) increases from F1 to F7 at time t2.

[0054] After time t3, the boss 8 contacts the first group of compression springs A, and the compression springs A generate contact resistance, the magnitude of which is linearly related to the displacement x.

[0055] After time t4, the size of F(x) at this time increases from F7 to F8 due to the action of the compression spring group A, and then the right end of the pull rod 15 contacts the protrusion 27. Under the action of the protrusion 27, the pull rod 15 rotates counterclockwise along the rotating sheath 26, and the constant force spring 13 is unhooked from the pull rod 15 through the pulley 14 under the inclination of the pull rod 15. The resistance of the constant force spring 13 stops working, and the size of F(x) drops from F8 to F2. The time period from t2 to t4 is mainly used to simulate the sudden appearance and disappearance of some resistance sources in the process of shifting gears of the automatic transmission. The resistance size is the calculated size value in the preparation stage, that is, the resistance size generated by the constant force spring 13.

[0056] After time t5, the magnitude of F(x) at this time increases from F2 to F4 due to the action of the compression spring group B, and the boss 8 contacts the second group of compression springs group B and the magnetic spring 10. The compression spring group B generates contact resistance, and its resistance magnitude is linearly related to the displacement x; the magnetic spring 10 generates a constant resistance, and its resistance magnitude is consistent with the preset initial value of the constant force of the spring itself.

[0057] After time t6, the size of F(x) at this time increases from F5 to F6 due to the action of the compression spring group B and the magnetic spring 10, and the upshift process is completed. After the displacement distance of the shift fork 6 reaches the set value, the shift motor 1 stops running, and the pressure tester 23 records the pressure change value of the whole process.

[0058] After the pressure tester 23 completes the recording, the shift motor 1 runs in the reverse direction, the shift fork 6 moves toward the shift motor 1, and the synchronous baffle 18 moves toward the shift motor 1 under the action of the compression spring group 9 and the magnetic spring 10 until the compression spring group 9 recovers its deformation and all components return to their original positions; the final test is completed.

[0059] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An automatic transmission shift actuator test device, characterized in that: The test device comprises: a shift motor (1), a gear set (2), a transmission shaft (3), a space cam (4), a cam groove (5), a shift fork (6) and a worm gear box (29); the shift motor (1) is directly connected to the upper gear of the gear set (2) after the motor shaft is decelerated through the worm gear box (29); one end of the transmission shaft (3) is directly connected to the lower gear of the gear set (2), and the other end is fixedly connected to the space cam (4); the shift fork (6) is embedded in the cam groove (5) on the space cam (4) through a connecting rod and moves along the groove track; The slide rail (19) is fixed on the bottom plate (16), and a spring baffle A (11) and a spring baffle B (12) are respectively installed on both sides of the slide rail (19); the constant force spring (13) is fixed on the spring baffle B (12) through a constant force spring support (30), and the compression spring group (9) and the magnetic spring (10) are fixed on the spring baffle A (11) through a compression spring support (25); the slider (17) cooperates with the slide rail (19) and slides on its track; the synchronous baffle (18) is installed on the slider (17), and a pressure sensor (7) is installed on one side of the synchronous baffle (18), and a boss (8) that cooperates with the compression spring group (9) is installed on the other side; the pressure sensor (7) is connected to the pressure tester (23) through a signal line (22), and the pressure tester (23) is fixed on the mounting baffle (24); The slide rail (19) is a T-shaped guide rail, and a protrusion (27) is provided in the middle of the slide rail (19). The upper part of the slider (17) is fixedly mounted with the synchronous baffle (18), and the lower part cooperates with the slide rail (19) and the I-shaped notch of the bottom plate (16); the middle part of the slider (17) includes a slider inner cavity (28) and a pull rod (15) fixed to the slider (17) through a rotating sheath (26), and a rotating spring is installed on the rotating sheath (26). When the pull rod (15) is in a horizontal state, the spring force is 0; the pull rod (15) can be rotated through the rotating sheath (26), and the other end of the pull rod (15) is hook-shaped and extends into a hole at one end of the constant force spring (13), and a pulley (14) is installed near the hole of the constant force spring (13) at one end of the slider (17); The synchronous baffle (18) can drive the slider (17) to move along the slide rail (19) through the shift fork (6); the boss (8) is a group of bosses distributed in sequence from top to bottom; the length of the protruding part of the boss (8) is determined by the resistance distribution during design and corresponds one-to-one with the compression spring group (9) and the magnetic spring (10); the boss (8) and the compression spring support (25) are detachable and can be installed with different spring groups and bosses; when the slider (17) moves toward the spring baffle A (11), the hook end of the pull rod (15) will drive the constant force spring (13) to generate a fixed resistance after a certain displacement; after the slider (17) passes the protrusion (27), the pull rod (15) rotates counterclockwise along the rotating sheath (26) as it contacts the protrusion (27), and then the hook end of the pull rod (15) moves downward and disconnects from the constant force spring (13) due to the action of the pulley (14).

2. The automatic transmission shift actuator test device according to claim 1, characterized in that: The shift motor (1) is fixedly mounted on a motor support (20), and the transmission shaft (3) is fixedly mounted on a cam mechanism support (21); the motor support (20) is spatially distributed in a step-by-step manner with the cam mechanism support (21) and the base plate (16); the upper gear and the lower gear of the gear set (2) cooperate with each other, and the shift motor (1) and the transmission shaft (3) are distributed at an angle of 90°.

3. The automatic transmission shift actuator test device according to claim 1, characterized in that: The profile of the cam groove (5) is a first gear, neutral gear and second gear travel profile designed according to the gear position; after the shift motor (1) is started, the torque is input to the worm gear box (29) through the motor shaft, and the gear set (2) is driven to rotate through the shaft, and the rotation of the lower gear of the gear set (2) drives the spatial cam (4) to rotate coaxially, and the shift fork (6) moves left and right along the profile of the cam groove (5) due to the rotation of the spatial cam (4), and when it moves in the direction of the synchronous baffle (18), it drives the baffle to move.

4. A testing method using the automatic transmission shift actuator testing device according to claim 1, characterized in that: The test method includes the following steps: 1) calculating the shift force required by the automatic transmission during the actual shifting process and the displacement distance of the shift fork (6), and setting different groups of compression spring groups (9), magnetic springs (10) and constant force springs (13) to simulate the shift force when different gear positions and vehicle speeds change; 2) Installing the set compression spring group (9), magnetic spring (10) and constant force spring (13) on the compression spring support (25) and the constant force spring support (30), and pushing the slider (17) and its synchronous baffle (18) to the initial end of the predetermined fork displacement stroke; 3) Setting the position of the constant force spring (13), wherein the hook end of the constant force spring (13) needs to contact the pull rod (15) to generate a constant resistance after the slider (17) reaches a predetermined position; 4) setting a controller program for controlling the gear shift motor (1) and matching it with the gear shift resistance set in the test to control the running speed of the gear shift motor (1); 5) Start the controller program, the shift motor (1) starts forward, and after the worm gear box (29) decelerates and increases torque, it drives the upper gear of the gear set (2) to rotate clockwise, while the lower gear drives the transmission shaft (3) and the space cam (4) to rotate counterclockwise; 6) At this time, the connection point of the shift fork (6) is located at the first gear contour of the cam groove (5). As the transmission shaft (3) rotates counterclockwise, the shift fork (6) begins to contact the pressure sensor (7) due to the change in the contour of the cam groove (5). The pressure sensor (7) transmits the pressure signal to the pressure tester (23) through the signal line (22). The shift fork (6) drives the synchronous baffle (18) and the slider (17) to move along the slide rail (19) in a direction away from the shift motor (1); 7) During the displacement of the synchronous baffle (18), due to the different lengths of the boss (8), the boss (8) sequentially contacts the compression spring group (9) and the magnetic spring (10) in different displacement strokes to generate resistance, thereby achieving the effect of simulating the change in the size of the resistance source of the automatic transmission in different strokes; 8) During the displacement of the slider (17), the pull rod (15) contacts the constant force spring (13) after reaching the set stroke, generating resistance. After the slider (17) continues to displace for a certain stroke, the right end of the pull rod (15) contacts the protrusion (27). Under the action of the protrusion (27), the pull rod (15) rotates counterclockwise along the rotating sheath (26). Under the inclination of the pull rod (15), the constant force spring (13) is decoupled from the pull rod (15) through the pulley (14) and stops generating resistance. This resistance is used to simulate the sudden appearance and disappearance of some resistance sources in the synchronization process of the automatic transmission; 9) After the displacement distance of the shift fork (6) reaches the set value, the shift motor (1) stops running, and the pressure tester (23) records the pressure change value of the whole process. After the recording is completed, the shift motor (1) runs in the reverse direction, the shift fork (6) moves in the direction of the shift motor (1), and the synchronous baffle (18) moves in the direction of the shift motor (1) under the action of the compression spring group (9) and the magnetic spring (10) until the compression spring group (9) recovers its deformation and all components return to their original positions; 10) Testing completed.

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