Automobile leaf spring testing mechanism and method

Abstract

The application relates to the technical field of automobile part testing, and discloses a kind of automobile plate spring testing mechanism and method, including rack, drive spindle and loading assembly, drive spindle is rotatably installed on the side plate of rack, eccentric wheel assembly is arranged on drive spindle, outer thread is arranged on the outer circumferential wall of drive spindle, loading assembly includes guide seat, vertical loading rod and torsion loading head, guide seat is installed on the inner side of the side plate of rack, the end of vertical loading rod is inserted in guide seat and reciprocatingly slides along vertical direction, the top end of vertical loading rod is provided with abutting plate, abutting plate abuts on the outer edge of eccentric wheel of eccentric wheel assembly, the outer circumferential wall of drive spindle is provided with double thread structure, eccentric wheel assembly is screwed in different thread segments to adjust the phase angle between eccentric wheel assembly and eccentric pin shaft, so as to change the phase difference of action time of vertical load and torsion load; the application can simulate the composite load spectrum of plate spring under the turning and rolling condition of new energy vehicle, and the test result is closer to real working condition.

Description

Technical Field

[0001] This invention relates to the field of automotive component testing technology, specifically to an automotive leaf spring testing mechanism and method. Background Technology

[0002] As a key load-bearing component of the automotive suspension system, the accurate assessment of the bending stress and fatigue performance of leaf springs directly affects the vehicle's driving safety and reliability. With the automotive industry's accelerated transformation towards new energy sources such as plug-in hybrid, pure electric, and fuel cell drives, the service conditions of leaf springs have changed significantly. New energy vehicles, equipped with core components such as battery packs, drive motors, and electronic control systems, exhibit fundamentally different vehicle mass distribution compared to traditional gasoline vehicles. The battery pack is typically located in the center of the chassis, altering the vertical load distribution pattern borne by the suspension system. Simultaneously, the high-frequency vibrations of the drive motor are transmitted to the leaf springs via the suspension system, subjecting them to a composite load spectrum with superimposed high-frequency excitation characteristics. This uneven load-bearing capacity in all directions places higher demands on testing equipment.

[0003] Regarding existing leaf spring testing technology, patent publication number CN109238674B discloses a quality inspection device for composite material automotive leaf springs. This device includes a base, a worktable fixedly mounted on the upper outer surface of the base, and a conveyor belt movably mounted on the upper outer surface of the worktable. A motor drives a rotating shaft via a connecting rod, which in turn moves the conveyor belt. A moving block fixed on the conveyor belt compresses the leaf spring, causing it to bend, thus enabling quality inspection of the leaf spring. However, this device can only achieve single vertical loading. When a new energy vehicle corners at high speed, the vehicle body tilts, and the suspension system bears significant lateral forces. At this time, the leaf spring's coil lug is subjected to road surface protrusions. The impact forces the leaf spring to deflect from its original trajectory. The torsional loading arm abuts against the leaf spring and applies an eccentric deflection force, causing the leaf spring end to bear a lateral load that does not pass through its shear center. This induces additional constraint torsional stress and lateral shear stress inside the leaf spring, in addition to the vertical bending stress. Under cornering fatigue conditions, the leaf spring must simultaneously bear the vertical load generated by the vehicle mass and the combined bending and torsional load generated by the deflection force. The two are superimposed and act together on the leaf spring. A single vertical loading device can only apply a centering normal force and cannot simulate the spatial deflection constraint at the leaf spring end, resulting in a significant deviation between the test results and the actual working conditions. Summary of the Invention

[0004] To address the technical problem that existing leaf spring testing equipment can only achieve single vertical loading, and cannot simulate the combined bending and torsional loads borne by leaf springs in new energy vehicles under turning or tilting conditions, resulting in significant deviations between test results and real working conditions, this paper aims to provide a testing mechanism and method for automotive leaf springs that can simultaneously apply vertical and torsional loads and adjust the phase relationship between the two.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: an automotive leaf spring testing mechanism, comprising a frame, a drive spindle and a loading assembly, wherein the drive spindle is rotatably mounted on the side plate of the frame, an eccentric wheel assembly is provided on the drive spindle, and an external thread is provided on the outer peripheral wall of the drive spindle;

[0006] The loading assembly includes a guide seat, a vertical loading rod, and a torsional loading head. The guide seat is installed inside the side plate of the frame. The end of the vertical loading rod passes through the guide seat and slides back and forth vertically. The top of the vertical loading rod is provided with an abutment plate, which abuts against the outer edge of the eccentric wheel of the eccentric wheel assembly. The bottom of the vertical loading rod is provided with a pressure head for pressing the leaf spring to be tested. The eccentric wheel assembly forces the vertical loading rod to move along the guide seat by abutting against the abutment plate, and the pressure head applies a periodic vertical load to the leaf spring.

[0007] A turntable is sleeved at the end of the drive spindle. A splitting assembly is provided between the turntable and the drive spindle. A torsional loading assembly is provided on the turntable. The torsional loading assembly includes a torsional loading head and a transmission mechanism. One end of the transmission mechanism is eccentrically connected to the turntable, and the other end of the transmission mechanism is connected to the torsional loading head. The torsional loading head is used to abut against the lug on one side of the leaf spring to apply an eccentric deflection force.

[0008] Preferably, the eccentric wheel assembly includes an annular block and an eccentric block, the drive spindle is a double screw structure, the drive spindle is provided with an external thread, the annular block is screwed onto the external thread, the annular block is provided with a groove, an adjusting screw is screwed into the annular block in the groove, and the bottom of the adjusting screw is rotatably connected to the eccentric block.

[0009] Preferably, strain gauges are attached to the vertical loading rod, and an elastic reset member is sleeved on the vertical loading rod between the guide seat and the abutment plate to provide an upward elastic reset force for the vertical loading rod. The strain gauges are used to measure the vertical loading load. A tightening nut is provided on the drive spindle to lock and fix the eccentric wheel assembly on the drive spindle. The circumferential position of the eccentric wheel assembly on the external thread changes the phase angle between the eccentric wheel assembly and the eccentric pin.

[0010] Preferably, the splitting and joining component includes a limiting head, a sliding groove on the turntable, a cylinder on the turntable, the limiting head being slidably inserted into the sliding groove, the limiting head being fixedly connected to the telescopic end of the cylinder, and a slot being provided on the drive spindle, with the limiting head and the slot correspondingly positioned.

[0011] Preferably, the transmission mechanism includes an eccentric pin, a first adjusting arm, and a second adjusting arm. The eccentric pin is fixedly connected to the edge of the turntable. One end of the first adjusting arm is rotatably connected to the eccentric pin. An adjusting assembly is provided between the first adjusting arm and the second adjusting arm. The other end of the second adjusting arm is connected to a hinge arm via a first universal joint. The other end of the hinge arm is rotatably connected to a second universal joint.

[0012] Preferably, the adjusting assembly includes a threaded rod and a threaded sleeve. The threaded rod is fixed to the end of the first adjusting arm, and the threaded sleeve is rotatably connected to the end of the second adjusting arm. The threaded rod and the threaded sleeve are threaded together. The second adjusting arm has a rotating groove. The threaded sleeve has a T-shaped structure, and its end is located in the rotating groove. An installation ring is provided at the opening of the rotating groove at the end of the second adjusting arm. The installation ring forms an axial limit on the threaded sleeve. The adjusting assembly adjusts the relative distance between the first and second adjusting arms to change the magnitude of the eccentric deflection force applied by the torsion loading head to one side of the leaf spring.

[0013] Preferably, the frame is provided with a hinge seat, and the second universal joint is fixed on the hinge seat. The hinge seat includes a ball head pin and a movable sleeve cover. The ball head pin is fixed on the hinge seat, and one end of the ball head pin forms a ball head. The movable sleeve cover is sleeved on the ball head pin and is fixedly connected to the torsion loading head. The movable sleeve cover swings relative to the ball head pin around the ball center, so that the torsion loading head adjusts the contact angle when it abuts against the leaf spring lug.

[0014] Preferably, a support base is fixedly installed on the frame, and a leaf spring limiting side plate is provided on the support base. A positioning groove for accommodating the leaf spring is formed between the two leaf spring limiting side plates. A lifting lug fixing member is provided on one side of the support base. The lifting lug fixing member is hinged to the lifting lug at the end of the leaf spring to simulate the fixed constraint state of the leaf spring in the actual suspension. The torsion loading head abuts against the outer wall of the other lug of the leaf spring.

[0015] Preferably, one end of the drive spindle is connected to a drive motor, and an angle encoder is provided on the drive spindle between the drive motor and the eccentric wheel assembly. A torque sensor is provided on the hinge seat. The angle encoder is used to collect the rotation angle signal of the drive spindle, and the torque sensor is used to collect the torsional load data borne by the leaf spring.

[0016] A method for testing an automotive leaf spring, the method being applied to the aforementioned automotive leaf spring testing mechanism, includes the following steps:

[0017] S1: Place the leaf spring to be tested upside down on the support base, align the pressure head with the middle section of the leaf spring, and hinge the lifting lug fixing part with the lifting lug at the end of the leaf spring. Twist the loading head to abut the coil lug on the other side of the leaf spring.

[0018] S2: Start the drive motor to make the drive spindle rotate. The eccentric wheel assembly rotates with the drive spindle and pushes against the abutment plate. The vertical loading rod reciprocates along the guide seat in the up and down direction. The pressure head applies a periodic vertical load to the leaf spring.

[0019] S3: When it is necessary to simulate a combined bending and torsion load, the turntable is in the engaged state. The turntable rotates synchronously with the drive spindle and drives the torsion loading head through the transmission mechanism to apply an eccentric deflection force to the leaf spring lug, so that the leaf spring bears both the vertical load and the combined bending and torsion load at the same time. When it is necessary to simulate only the vertical loading load, the turntable is in the disengaged state and the drive spindle rotates freely.

[0020] S4: By rotating the eccentric wheel assembly along the external thread on the drive spindle, the circumferential relative angle between the eccentric wheel assembly and the eccentric pin shaft is changed to adjust the time phase difference between the vertical load applied by the pressure head and the eccentric deflection force applied by the torsional loading head, so that the peak value of the vertical load and the peak value of the lateral deflection force are in phase angle relationship in time, so as to simulate the load action mode under different road surface excitation.

[0021] S5: By rotating the threaded sleeve of the adjustment component, the relative distance between the first adjustment arm and the second adjustment arm is changed, thereby changing the magnitude of the force of the eccentric deflection force transmitted to the torsional loading head through the transmission mechanism;

[0022] S6: Continue running until the leaf spring reaches the preset number of fatigue cycles. The rotation angle signal of the drive spindle is collected in real time through the angle encoder. Based on the rotation angle signal, the vertical load data detected by the strain gauge and the torsional load data detected by the torque sensor are recorded simultaneously. The test data is recorded and the composite load-bearing performance of the leaf spring is evaluated.

[0023] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0024] 1. This invention sets up a turntable and a splitting assembly, and eccentrically connects a transmission mechanism on the turntable, so that the torsional loading head can apply an eccentric deflection force to the leaf spring lug. Combined with the periodic vertical load applied to the middle section of the leaf spring by the vertical loading rod, it realizes simultaneous vertical loading and bending-torsional composite loading of the leaf spring. It can realistically simulate the composite load spectrum of the leaf spring under the turning condition of new energy vehicles, overcome the defect of the existing technology that can only perform single vertical loading, and the test results are closer to the real working conditions.

[0025] 2. This invention sets the external thread of the drive spindle to a double-threaded structure, allowing the eccentric wheel assembly to be installed on different thread sections. This changes the circumferential starting angle of the eccentric wheel assembly relative to the drive spindle, thereby adjusting the phase angle between the eccentric wheel assembly and the eccentric pin. This enables precise adjustment of the phase difference between the vertical load and the torsional load, simulating load phase change patterns under different road surface excitations. It is more adaptable and provides a more comprehensive testing method for evaluating the fatigue performance of leaf springs under different road conditions.

[0026] 3. This invention achieves continuous stepless adjustment of the transmission mechanism length by setting an adjustment assembly consisting of a threaded rod and a threaded sleeve between the first and second adjustment arms, and by using an installation ring to axially limit the threaded sleeve. This allows for precise change of the magnitude of the eccentric deflection force applied by the torsion loading head to the leaf spring lug, adapting to the testing requirements of different types of leaf springs. By setting a hinge seat consisting of a ball-head pin and a movable sleeve cover, a ball-joint connection is formed between the torsion loading head and the hinge seat. When the torsion loading head abuts the leaf spring lug, it can automatically adjust the contact angle according to the spatial deflection posture of the lug, ensuring that the torsion loading head always abuts against the outer wall of the lug at the optimal angle, avoiding local stress concentration caused by contact angle deviation, and improving the accuracy of load application and the reliability of test results. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the automotive leaf spring testing mechanism of the present invention.

[0028] Figure 2 This is a schematic diagram of the other side of the automotive leaf spring testing mechanism of the present invention.

[0029] Figure 3 This is a schematic diagram of the structure of the loading component of the present invention.

[0030] Figure 4 This is a schematic diagram of the eccentric wheel assembly and the turntable installation of the present invention.

[0031] Figure 5 This is a schematic diagram of the adjustment structure of the eccentric wheel assembly of the present invention.

[0032] Figure 6 This is a schematic diagram of the structure of the splitting and merging component of the present invention.

[0033] Figure 7 This is an enlarged structural schematic diagram of the torsion loading component of the present invention.

[0034] Figure 8 This is a schematic diagram of the structure of the adjustment component of the present invention.

[0035] Figure 9 This is an exploded structural diagram of the threaded sleeve and the second adjusting arm of the present invention.

[0036] Figure 10 This is a schematic diagram of the torsion loading head of the present invention.

[0037] In the diagram: 1. Frame; 2. Drive spindle; 21. Drive motor; 22. Angle encoder; 23. External thread; 24. Tightening nut; 3. Loading assembly; 31. Guide seat; 4. Eccentric wheel assembly; 401. Circular block; 402. Eccentric block; 403. Groove; 404. Adjusting screw; 41. Vertical loading rod; 411. Strain gauge; 42. Abutment plate; 43. Pressure head; 44. Elastic reset component; 5. Turntable; 501. Cylinder; 502. Slide groove; 503. Limit head; 50 4. Slot; 505. Limit nut; 51. Torque loading head; 52. Eccentric pin; 53. First adjusting arm; 54. Second adjusting arm; 55. Hinge arm; 56. First universal joint; 57. Second universal joint; 58. Torque sensor; 6. Hinge seat; 61. Ball pin; 62. Movable sleeve cover; 7. Adjusting assembly; 71. Threaded rod; 72. Threaded sleeve; 73. Rotating groove; 74. Mounting ring; 8. Support seat; 81. Leaf spring limiting side plate; 82. Lifting lug fixing piece. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0039] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "comprising" or "including," and similar terms used in this disclosure, mean that an element or object preceding the term encompasses the elements or objects listed following the term and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but may also include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0040] like Figure 1 and Figure 2As shown, an automotive leaf spring testing mechanism includes a frame 1, a drive spindle 2, and a loading assembly 3. The frame 1 is a frame structure, including a base plate and two side plates. The drive spindle 2 is rotatably mounted between the two side plates of the frame 1 via bearings. One end of the drive spindle 2 extends out of the side plate and is connected to a drive motor 21. Specifically, both ends of the drive spindle 2 are rotatably connected to the two side plates of the frame 1, allowing the drive spindle 2 to rotate freely around its own axis. One end of the drive spindle 2 extends out of the side plate and is fixedly connected to the drive motor 21 via a coupling. The drive motor 21 is fixedly mounted on the outer side wall of the frame 1 by bolts, providing a single power source for the entire testing mechanism.

[0041] like Figure 3 As shown, the loading assembly 3 includes a guide seat 31, a vertical loading rod 41, and a torsional loading head 51. The guide seat 31 is fixedly installed on the inner side of the side plate of the frame 1. The guide seat 31 is located below the drive spindle 2. A vertical guide hole is provided on the guide seat 31. The vertical loading rod 41 passes through the vertical guide hole and slides back and forth vertically. An abutment plate 42 is fixedly provided at the top of the vertical loading rod 41. The upper surface of the abutment plate 42 abuts against the outer edge of the eccentric wheel of the eccentric wheel assembly 4. A pressure head 43 is fixedly provided at the bottom of the vertical loading rod 41. The pressure head 43 is used to press against the upper surface of the leaf spring to be tested. When the drive spindle 2 drives the eccentric wheel assembly 4 to rotate, the outer edge of the eccentric wheel forces the vertical loading rod 41 to slide back and forth along the vertical guide hole of the guide seat 31 through the abutment plate 42. The pressure head 43 applies a periodically changing vertical load to the leaf spring.

[0042] A strain gauge 411 is attached to the vertical loading rod 41. The strain gauge 411 is a full-bridge resistance strain gauge used to measure the vertical loading load in real time. An elastic reset member 44 is sleeved on the vertical loading rod 41 between the guide seat 31 and the abutment plate 42. One end of the elastic reset member 44 abuts against the upper surface of the guide seat 31 and the other end abuts against the lower surface of the abutment plate 42. It is used to provide an upward elastic reset force for the vertical loading rod 41 to ensure that the abutment plate 42 always remains in contact with the outer edge of the eccentric wheel.

[0043] like Figure 4 and Figure 5 As shown, an eccentric wheel assembly 4 is provided on the drive spindle 2. The eccentric wheel assembly 4 includes an annular block 401 and an eccentric block 402. An internal thread is provided on the inner wall of the annular block 401. The annular block 401 is threadedly connected to the external thread 23 on the drive spindle 2 through the internal thread, so that the annular block 401 can be screwed in or out along the axial direction of the drive spindle 2, thereby adjusting the axial position of the eccentric wheel assembly 4 on the drive spindle 2.

[0044] A groove 403 is provided on one side of the outer peripheral wall of the ring block 401. An adjusting screw 404 is threadedly connected to the ring block 401 within the groove 403. Specifically, a threaded through hole is provided at the top of the ring block 401, extending into the groove 403. The adjusting screw 404 passes through the threaded through hole and is threadedly engaged with the ring block 401. The bottom of the adjusting screw 404 extends into the groove 403 and is rotatably connected to an eccentric block 402 via a thrust bearing. The eccentric block 402 has a fan-shaped arc structure. The bottom arc surface of the eccentric block 402 is the abutment working surface for abutting the abutment plate 42. By rotating the adjusting screw 404, the height position of the eccentric block 402 extending out of the bottom of the groove 403 is adjusted, thereby changing the overall eccentricity of the eccentric wheel assembly 4, that is, changing the radial distance between the outer edge of the eccentric wheel and the rotation axis of the drive spindle 2, and thus adjusting the vertical loading stroke of the vertical loading rod 41.

[0045] The eccentric wheel assembly 4 is threadedly engaged with the external thread 23 on the drive spindle 2 via the ring block 401 and locked in place by tightening the nut 24. Since the external thread 23 is a double thread structure, the position of the eccentric wheel assembly 4 can be adjusted on two thread segments. When the eccentric wheel assembly 4 is installed on different thread segments, its circumferential starting angle relative to the drive spindle 2 changes, thereby adjusting the phase angle between the eccentric wheel assembly 4 and the eccentric pin 52, and realizing the adjustment of the phase difference between the action time of the vertical load and the torsional load.

[0046] like Figure 3 As shown, an angle encoder 22 is installed on the drive spindle 2 between the drive motor 21 and the eccentric wheel assembly 4. The detection end of the angle encoder 22 is coaxially connected to the drive spindle 2 and is used to collect the rotation angle signal of the drive spindle 2 in real time, providing a time reference for the synchronous recording of subsequent load data.

[0047] like Figure 4 As shown, the outer peripheral wall of the drive spindle 2 is provided with an external thread 23. The external thread 23 is a double thread structure, that is, two thread segments with the same direction of rotation but different starting positions are machined along the axial direction on the outer peripheral wall of the drive spindle 2. There is a gap between the two thread segments for threaded engagement with the eccentric wheel assembly 4. The drive spindle 2 is also provided with a tightening nut 24. The tightening nut 24 is sleeved on the drive spindle 2 and threadedly engaged with the external thread 23. The tightening nut 24 is located on both sides of the eccentric wheel assembly 4, with one on each side, for locking and fixing the eccentric wheel assembly 4 to a predetermined axial position on the drive spindle 2 to prevent the eccentric wheel assembly 4 from axially moving during the rotation of the drive spindle 2.

[0048] like Figure 3 and Figure 6As shown, a turntable 5 is sleeved at the end of the drive spindle 2. The turntable 5 has a disc-shaped structure. A splitting assembly is provided between the turntable 5 and the drive spindle 2 to control the engagement and disengagement between the turntable 5 and the drive spindle 2. The splitting assembly includes a limiting head 503. A sliding groove 502 is radially opened on the surface of the turntable 5. A cylinder 501 is fixedly connected to the surface of the turntable 5 by bolts. The cylinder body of the cylinder 501 is fixedly installed on the surface of the turntable 5. The telescopic end of the cylinder 501 extends toward the sliding groove 502.

[0049] The limiting head 503 is slidably inserted into the slide groove 502, and the bottom of the limiting head 503 forms a sliding fit with the slide groove 502. The top of the limiting head 503 is fixedly connected to the telescopic end of the cylinder 501. The telescopic action of the cylinder 501 drives the limiting head 503 to slide back and forth along the slide groove 502. A slot 504 is provided at a corresponding position on the outer peripheral wall of the end of the drive spindle 2. The limiting head 503 and the slot 504 are correspondingly arranged. When the cylinder 501 extends, the limiting head 503 is inserted into the slot 504, so that the turntable 5 and the drive spindle 2 form a circumferential fixed connection, and the turntable 5 rotates synchronously with the drive spindle 2. When the cylinder 501 retracts, the limiting head 503 is dislodged from the slot 504, the turntable 5 is separated from the drive spindle 2, and the drive spindle 2 rotates freely in the shaft hole of the turntable 5 but cannot drive the turntable 5 to rotate.

[0050] like Figure 3 and Figure 7 As shown, a torsional loading assembly is provided on the turntable 5. The torsional loading assembly includes a torsional loading head 51 and a transmission mechanism. One end of the transmission mechanism is eccentrically connected to the turntable 5, and the other end of the transmission mechanism is connected to the torsional loading head 51. The torsional loading head 51 is used to abut against the lug on one side of the leaf spring to apply an eccentric deflection force.

[0051] Specifically, the transmission mechanism includes an eccentric pin 52, a first adjusting arm 53, and a second adjusting arm 54. The eccentric pin 52 is fixedly connected to the edge of the turntable 5. Specifically, one end of the eccentric pin 52 is fixedly connected to the edge of the turntable 5 by bolts. The eccentric pin 52 has a defined eccentricity relative to the rotation axis of the drive spindle 2. One end of the first adjusting arm 53 is rotatably connected to the eccentric pin 52 by a bearing, so that the first adjusting arm 53 can swing freely around the axis of the eccentric pin 52.

[0052] An adjustment assembly 7 is provided between the first adjustment arm 53 and the second adjustment arm 54 for adjusting the relative distance between them. The other end of the second adjustment arm 54 is fixedly connected to a first universal joint 56. The driving end of the first universal joint 56 is fixedly connected to the end of the second adjustment arm 54 by bolts. The driven end of the first universal joint 56 is fixedly connected to a hinge arm 55, which is a rigid rod-shaped component. The other end of the hinge arm 55 is rotatably connected to a second universal joint 57. Specifically, the end of the hinge arm 55 is rotatably connected to the driving end of the second universal joint 57 by a pin. The driven end of the second universal joint 57 is fixedly connected to the hinge seat 6 provided on the frame 1 by bolts.

[0053] like Figure 8 and Figure 9 As shown, the adjusting assembly 7 includes a threaded rod 71 and a threaded sleeve 72. One end of the threaded rod 71 is welded and fixed to the end of the first adjusting arm 53. The threaded rod 71 extends outward along the length of the first adjusting arm 53. The threaded sleeve 72 is rotatably connected to the end of the second adjusting arm 54. Specifically, the end of the second adjusting arm 54 is provided with a rotating groove 73. The threaded sleeve 72 has an overall T-shaped structure. The large-diameter end of the threaded sleeve 72 is located in the rotating groove 73, and the small-diameter end of the threaded sleeve 72 extends out from the opening of the rotating groove 73. The inner wall of the threaded sleeve 72 is machined with internal threads. The threaded rod 71 passes through the inner hole of the threaded sleeve 72 and is threadedly connected to the threaded sleeve 72.

[0054] The end of the second adjusting arm 54 is fixedly connected to the mounting ring 74 by bolts at the opening of the rotating groove 73. The inner diameter of the mounting ring 74 is smaller than the outer diameter of the large diameter end of the threaded sleeve 72 but larger than the outer diameter of the small diameter end of the threaded sleeve 72. The mounting ring 74 forms an axial limit on the threaded sleeve 72, so that the threaded sleeve 72 can only rotate relative to the second adjusting arm 54 and cannot move axially. By rotating the threaded sleeve 72, the threaded rod 71 is screwed in or out relative to the threaded sleeve 72, thereby changing the relative distance between the first adjusting arm 53 and the second adjusting arm 54, so as to change the magnitude of the eccentric deflection force applied by the torsion loading head 51 to one side of the leaf spring.

[0055] like Figure 10As shown, a hinge seat 6 is fixedly installed on the frame 1, and a second universal joint 57 is fixed on the hinge seat 6. Specifically, the hinge seat 6 includes a ball head pin 61 and a movable sleeve cover 62. The lower end of the ball head pin 61 is welded and fixed to the top of the hinge seat 6, and the upper end of the ball head pin 61 is integrally formed with a ball head. The ball head has a spherical structure. The movable sleeve cover 62 has a sleeve-shaped structure, and the inner cavity of the movable sleeve cover 62 is a spherical concave surface that matches the ball head of the ball head pin 61. The movable sleeve cover 62 is fitted onto the ball head of the ball head pin 61, and the movable sleeve cover 62 and the ball head of the ball head pin 61 form a ball joint fit. This allows the movable sleeve 62 to swing relative to the ball head pin 61 around the center of the ball. The movable sleeve 62 is fixedly connected to the torsion loading head 51. Specifically, the torsion loading head 51 has a block structure. One end of the torsion loading head 51 is fixedly connected to the outer wall of the movable sleeve 62 by bolts. The movable sleeve 62 swings relative to the ball head pin 61 around the center of the ball, so that the torsion loading head 51 can automatically adjust the contact angle according to the spatial posture of the leaf spring lug when it abuts against it. This ensures that the torsion loading head 51 abuts against the outer wall of the lug at the optimal angle, avoiding local stress concentration caused by contact angle deviation.

[0056] like Figure 2 As shown, a support base 8 is fixedly installed on the frame 1. The bottom of the support base 8 is fixedly connected to the frame 1 by bolts. Leaf spring limiting side plates 81 are vertically installed on both sides of the support base 8. A positioning groove for accommodating the leaf spring is formed between the two leaf spring limiting side plates 81. The width of the positioning groove is adapted to the width of the leaf spring to be tested, and is used to limit the leaf spring in the horizontal direction to prevent the leaf spring from moving laterally during the test.

[0057] A lug fixing member 82 is provided on one side of the support seat 8. The lug fixing member 82 is a U-shaped seat structure. The lug fixing member 82 is fixedly connected to the support seat 8 by bolts. The lug fixing member 82 is hinged to the lug at the end of the leaf spring to simulate the fixed constraint state of the leaf spring in the actual suspension. Specifically, in the actual vehicle suspension, one end of the leaf spring is hinged to the frame through the lug, and the other end is fixedly connected to the frame through the fixed bracket. In this embodiment, the lug fixing member 82 is hinged to the lug at one end of the leaf spring to simulate the hinge constraint boundary conditions in the actual suspension, so that the stress state of the leaf spring during the test is closer to the real working condition. The torsion loading head 51 abuts against the outer wall of the other lug of the leaf spring. When the torsion loading head 51 moves with the transmission mechanism, it applies an eccentric deflection force to the lug on that side of the leaf spring to simulate the lateral deflection force borne by the end of the leaf spring when the vehicle turns.

[0058] like Figure 1 and Figure 2As shown, a torque sensor 58 is installed on the hinge seat 6. The detection end of the torque sensor 58 is connected to the movable sleeve cover 62 and is used to collect the torsional load data borne by the leaf spring. Angle encoder 22 is used to collect the rotation angle signal of the drive spindle 2. Torque sensor 58 is used to collect the torsional load data borne by the leaf spring. Together with strain gauge 411, they form a synchronous acquisition system to provide data support for the comprehensive evaluation of the composite load-bearing performance of the leaf spring. Strain gauge 411, torque sensor 58 and angle encoder 22 are all connected to the same multi-channel data acquisition card. The data acquisition card is connected to the industrial control computer through the PCI interface. During the test, the data acquisition card uses the rotation angle signal of angle encoder 22 as the external clock trigger source to synchronously collect data from each channel to ensure that all data are strictly aligned on the time axis.

[0059] Based on the above structure, the working method of the automotive leaf spring testing mechanism of the present invention includes the following steps:

[0060] S1: Place the leaf spring to be tested upside down on the support base 8, with the arch of the leaf spring facing down and the two end lugs facing up, so that the pressure head 43 is aligned with the middle section of the leaf spring, and the lug fixing member 82 is hinged to the lug at the end of the leaf spring. The lug at one end of the leaf spring is sleeved on the pin of the lug fixing member 82 to form a hinge constraint, and the loading head 51 is twisted to abut against the outer wall of the lug on the other side of the leaf spring.

[0061] S2: The drive spindle 2 drives the eccentric block 402 to rotate. The outer edge of the eccentric block 402 makes an eccentric motion during rotation. When the outer edge of the eccentric block 402 applies a downward thrust to the abutment plate 42, the abutment plate 42 drives the vertical loading rod 41 to overcome the elastic force of the elastic reset member 44 and slide downward along the vertical guide hole of the guide seat 31. The pressure head 43 at the bottom of the vertical loading rod 41 presses down on the upper surface of the leaf spring, applying a downward vertical load to the leaf spring. When the outer edge of the eccentric block 402 returns upward... During the process, the elastic reset member 44 pushes the abutment plate 42 to reset upward, the vertical loading rod 41 slides upward, and the vertical load on the leaf spring by the pressure head 43 decreases. As the drive spindle 2 rotates continuously, the vertical loading rod 41 slides periodically in the vertical direction, and the pressure head 43 applies a periodically changing vertical load to the leaf spring. The strain gauge 411 detects the strain of the vertical loading rod 41 in real time and transmits the strain signal to the data acquisition unit. After conversion, the real-time vertical load value is obtained.

[0062] S3: When it is necessary to simulate the combined bending and torsion conditions, start the cylinder 501 to extend its telescopic end, push the limit head 503 to slide along the slide groove 502 towards the drive spindle 2, so that the limit head 503 is inserted into the slot 504 at the end of the drive spindle 2, the turntable 5 is in the engaged state, the turntable 5 rotates synchronously with the drive spindle 2, when the turntable 5 rotates, the eccentric pin 52 makes a circular motion around the rotation axis of the drive spindle 2, and through the transmission mechanism composed of the first adjusting arm 53, adjusting component 7, second adjusting arm 54, first universal joint 56, hinge arm 55 and second universal joint 57, the eccentric rotational motion is converted into the reciprocating swing motion of the torsion loading head 51. The torsion loading head 51 applies an eccentric deflection force to the leaf spring lug, so that the leaf spring bears both vertical load and combined bending and torsion load at the same time, simulating the combined load borne by the leaf spring of a new energy vehicle under turning or tilting conditions;

[0063] When only vertical loading conditions need to be simulated, the cylinder 501 is activated to retract its telescopic end, pulling the limit head 503 to slide away from the drive spindle 2 along the slide groove 502, so that the limit head 503 is completely disengaged from the slot 504, the turntable 5 is in a separated state, the drive spindle 2 rotates freely in the shaft hole of the turntable 5, the turntable 5 remains stationary, the torsional loading component does not work, the drive spindle 2 rotates freely, and the leaf spring only bears the periodic vertical load from the pressure head 43.

[0064] S4: When it is necessary to adjust the phase difference between the action time of the vertical load and the torsional load, first loosen the tightened nut 24 to release the locking fixation of the eccentric wheel assembly 4. Then, the operator rotates the ring block 401 by hand, so that the ring block 401 rotates along the external thread 23 on the drive spindle 2. Since the external thread 23 on the drive spindle 2 is a double thread structure, the ring block 401 can be selectively screwed into different thread sections, thereby changing the axial position and circumferential starting angle of the eccentric wheel assembly 4 on the drive spindle 2. When the eccentric wheel assembly 4 is installed on different thread sections, the circumferential angle of the distal end of the eccentric block 402 relative to the drive spindle 2 changes, that is, the circumferential relative angle between the eccentric wheel assembly 4 and the eccentric pin 52 changes. Since the vertical load is resisted by the eccentric block 402 of the eccentric wheel assembly 4, the vertical load is resisted by the eccentric block 402 of the eccentric wheel assembly 4. The push-off plate 42 generates the torsional load, which is generated by the eccentric pin 52 rotating with the turntable 5 and transmitted through the transmission mechanism. Both are driven by the same drive shaft 2, but the phase of action depends on the circumferential angle between the distal end of the eccentric block 402 and the eccentric pin 52. By adjusting the circumferential angle, the phase difference between the vertical load applied by the pressure head 43 and the eccentric deflection force applied by the torsional loading head 51 can be adjusted, so that the peak value of the vertical load and the peak value of the lateral deflection force have a specific phase angle relationship in time, so as to simulate the load action mode under different road surface excitations, such as simulating the load phase change when a vehicle drives alternately on raised road surface and pothole road surface. After the adjustment is completed, tighten the tightening nut 24 to lock and fix the eccentric wheel assembly 4 on the drive shaft 2 to prevent the eccentric wheel assembly 4 from loosening during the test.

[0065] S5: When it is necessary to adjust the magnitude of the eccentric deflection force applied by the torsion loading head 51, the operator uses a wrench to clamp the outer peripheral wall of the threaded sleeve 72 and rotates the threaded sleeve 72. Since the threaded sleeve 72 is axially limited by the mounting ring 74 and cannot move axially, the rotation of the threaded sleeve 72 causes the threaded rod 71 to screw in or out relative to the threaded sleeve 72, thereby changing the relative distance between the first adjusting arm 53 and the second adjusting arm 54. When the distance between the first adjusting arm 53 and the second adjusting arm 54 increases, the overall length of the transmission mechanism increases, and the lever arm of the eccentric movement of the eccentric pin 52 transmitted to the torsion loading head 51 through the transmission mechanism changes. The force value of the eccentric deflection force applied by the torsion loading head 51 to the leaf spring lug changes accordingly. Conversely, when the distance decreases, the force value of the eccentric deflection force decreases accordingly. Through the adjustment of the adjustment component 7, the continuous stepless adjustment of the eccentric deflection force value can be achieved to adapt to the testing requirements of different types of leaf springs.

[0066] S6: The test mechanism is continuously operated to keep the drive motor 21 running. The pressure head 43 applies a periodic vertical load to the leaf spring, while the torsion loading head 51 selectively applies a periodic eccentric deflection force to the leaf spring according to the state of the splitting and engaging components. The leaf spring continues to deform under the combined load until the preset number of fatigue cycles is reached.

[0067] During the test, the angle encoder 22 acquires the rotation angle signal of the drive spindle 2 in real time, the strain gauge 411 detects the axial strain of the vertical loading rod 41 in real time and converts it into vertical load data, and the torque sensor 58 detects the torque borne by the hinge seat 6 in real time and converts it into torsional load data of the leaf spring. All data are transmitted to an external data acquisition system. Based on the rotation angle signal acquired by the angle encoder 22, the data acquisition system synchronously records the vertical load data and torsional load data corresponding to each angle position, forming a three-dimensional data matrix of load, angle, and time. After the test, the leaf spring is removed and the surface of the leaf spring is observed for fatigue failure phenomena such as cracks and fractures. The composite load-bearing performance and fatigue life of the leaf spring are evaluated in combination with the recorded load data, providing experimental basis for the matching development of the structural optimization design of the leaf spring.

[0068] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. A testing mechanism for automotive leaf springs, comprising a frame (1), a drive spindle (2), and a loading assembly (3), characterized in that: The drive spindle (2) is rotatably mounted on the side plate of the frame (1). An eccentric wheel assembly (4) is provided on the drive spindle (2), and an external thread (23) is provided on the outer peripheral wall of the drive spindle (2). The loading assembly (3) includes a guide seat (31), a vertical loading rod (41), and a torsion loading head (51). The guide seat (31) is installed on the inner side of the side plate of the frame (1). The end of the vertical loading rod (41) is inserted into the guide seat (31) and slides back and forth vertically. The top of the vertical loading rod (41) is provided with an abutment plate (42), which abuts against the outer edge of the eccentric wheel of the eccentric wheel assembly (4). The bottom of the vertical loading rod (41) is provided with a pressure head (43) for pressing the leaf spring to be tested. The eccentric wheel assembly (4) forces the vertical loading rod (41) to move along the guide seat (31) by abutting against the abutment plate (42). The pressure head (43) applies a periodic vertical load to the leaf spring. The end of the drive spindle (2) is fitted with a turntable (5), and a splitting assembly is provided between the turntable (5) and the drive spindle (2). A torsional loading assembly is provided on the turntable (5). The torsional loading assembly includes a torsional loading head (51) and a transmission mechanism. One end of the transmission mechanism is eccentrically connected to the turntable (5), and the other end of the transmission mechanism is connected to the torsional loading head (51). The torsional loading head (51) is used to abut against the lug on one side of the leaf spring to apply an eccentric deflection force.

2. The automotive leaf spring testing mechanism according to claim 1, characterized in that: The eccentric wheel assembly (4) includes an annular block (401) and an eccentric block (402). The drive spindle (2) is a double screw structure. An external thread (23) is provided on the drive spindle (2). The annular block (401) is screwed onto the external thread (23). A groove (403) is provided on the annular block (401). An adjusting screw (404) is screwed into the groove (403) on the annular block (401). The bottom of the adjusting screw (404) is rotatably connected to the eccentric block (402).

3. The automotive leaf spring testing mechanism according to claim 1, characterized in that: The vertical loading rod (41) is fitted with a strain gauge (411), and an elastic reset member (44) is sleeved on the vertical loading rod (41) between the guide seat (31) and the abutment plate (42) to provide an upward elastic reset force for the vertical loading rod (41). The strain gauge (411) is used to measure the vertical loading load. A tightening nut (24) is provided on the drive spindle (2). The tightening nut (24) is used to lock and fix the eccentric wheel assembly (4) on the drive spindle (2). The circumferential position of the eccentric wheel assembly (4) on the external thread (23) changes the phase angle between the eccentric wheel assembly (4) and the eccentric pin (52).

4. The automotive leaf spring testing mechanism according to claim 1, characterized in that: The splitting and joining assembly includes a limiting head (503), a slide groove (502) on the turntable (5), a cylinder (501) on the turntable (5), the limiting head (503) is slidably inserted into the slide groove (502), the limiting head (503) is fixedly connected to the telescopic end of the cylinder (501), and a slot (504) is provided on the drive spindle (2). The limiting head (503) and the slot (504) are correspondingly arranged.

5. The automotive leaf spring testing mechanism according to claim 1, characterized in that: The transmission mechanism includes an eccentric pin (52), a first adjusting arm (53), and a second adjusting arm (54). The eccentric pin (52) is fixedly connected to the edge of the turntable (5). One end of the first adjusting arm (53) is rotatably connected to the eccentric pin (52). An adjusting assembly is provided between the first adjusting arm (53) and the second adjusting arm (54). The other end of the second adjusting arm (54) is connected to a hinge arm (55) through a first universal joint (56). The other end of the hinge arm (55) is rotatably connected to a second universal joint (57).

6. The automotive leaf spring testing mechanism according to claim 5, characterized in that: The adjusting assembly (7) includes a threaded rod (71) and a threaded sleeve (72). The threaded rod (71) is fixed to the end of the first adjusting arm (53), and the threaded sleeve (72) is rotatably connected to the end of the second adjusting arm (54). The threaded rod (71) and the threaded sleeve (72) are threaded together. The second adjusting arm (54) has a rotating groove (73). The threaded sleeve (72) has a T-shaped structure and its end is located in the rotating groove (73). The end of the second adjusting arm (54) is provided with an installation ring (74) at the opening of the rotating groove (73). The installation ring (74) forms an axial limit on the threaded sleeve (72). The adjusting assembly (7) adjusts the relative distance between the first adjusting arm (53) and the second adjusting arm (54) to change the magnitude of the eccentric deflection force applied by the torsion loading head (51) to one side of the leaf spring.

7. The automotive leaf spring testing mechanism according to claim 1, characterized in that: The frame (1) is provided with a hinge seat (6), and a second universal joint (57) is fixed on the hinge seat (6). The hinge seat (6) includes a ball head pin (61) and a movable sleeve cover (62). The ball head pin (61) is fixed on the hinge seat (6), and one end of the ball head pin (61) forms a ball head. The movable sleeve cover (62) is sleeved on the ball head of the ball head pin (61). The movable sleeve cover (62) is fixedly connected to the torsion loading head (51). The movable sleeve cover (62) swings around the center of the ball head pin (61) relative to the ball head pin (61), so that the torsion loading head (51) adjusts the contact angle when it abuts against the leaf spring lug.

8. The automotive leaf spring testing mechanism according to claim 1, characterized in that: A support base (8) is fixedly installed on the frame (1). A leaf spring limiting side plate (81) is installed on the support base (8). A positioning groove for accommodating the leaf spring is formed between the two leaf spring limiting side plates (81). A lug fixing member (82) is provided on one side of the support base (8). The lug fixing member (82) is hinged to the lug at the end of the leaf spring to simulate the fixed constraint state of the leaf spring in the actual suspension. The torsion loading head (51) abuts against the outer wall of the other lug of the leaf spring.

9. The automotive leaf spring testing mechanism according to claim 1, characterized in that: One end of the drive spindle (2) is connected to a drive motor (21). An angle encoder (22) is provided on the drive spindle (2) between the drive motor (21) and the eccentric wheel assembly (4). A torque sensor (58) is provided on the hinge seat (6). The angle encoder (22) is used to collect the rotation angle signal of the drive spindle (2), and the torque sensor (58) is used to collect the torsional load data borne by the leaf spring.

10. A method for testing an automotive leaf spring, the method being applied to the automotive leaf spring testing mechanism as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: Place the leaf spring to be tested upside down on the support base (8), align the pressure head (43) with the middle section of the leaf spring, and hinge the lug fixing piece (82) with the lug at the end of the leaf spring, and twist the loading head (51) to abut the lug on the other side of the leaf spring. S2: Start the drive motor (21) to make the drive spindle (2) rotate. The eccentric wheel assembly (4) rotates with the drive spindle (2) and pushes against the abutment plate (42). The vertical loading rod (41) moves back and forth along the guide seat (31) in the up and down direction. The pressure head (43) applies a periodic vertical load to the leaf spring. S3: When it is necessary to simulate the combined bending and torsion conditions, the turntable (5) is in the engaged state. The turntable (5) rotates synchronously with the drive spindle (2) and drives the torsion loading head (51) through the transmission mechanism to apply an eccentric deflection force to the leaf spring lug, so that the leaf spring bears both the vertical load and the combined bending and torsion load at the same time. When it is necessary to simulate only the vertical loading conditions, the turntable (5) is in the disengaged state, and the drive spindle (2) rotates idling. S4: By rotating the eccentric wheel assembly (4) along the external thread (23) on the drive spindle (2), the circumferential relative angle between the eccentric wheel assembly (4) and the eccentric pin (52) is changed, so as to adjust the phase difference of the action time of the vertical load applied by the pressure head (43) and the eccentric deflection force applied by the torsional loading head (51), so that the peak value of the vertical load and the peak value of the lateral deflection force are in phase angle relationship in time, so as to simulate the load action mode under different road surface excitation. S5: By rotating the threaded sleeve (72) of the adjustment assembly (7), the relative distance between the first adjustment arm (53) and the second adjustment arm (54) is changed, so as to change the magnitude of the force of the eccentric deflection force transmitted to the torsional loading head (51) through the transmission mechanism; S6: Continue running until the leaf spring reaches the preset number of fatigue cycles. The rotation angle signal of the drive spindle (2) is collected in real time by the angle encoder (22). The vertical load data detected by the strain gauge (411) and the torsional load data detected by the torque sensor (58) are recorded synchronously according to the rotation angle signal. The test data are recorded and the composite load-bearing performance of the leaf spring is evaluated.

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