Automobile suspension spring durability test device and test method

Abstract

The present application relates to spring durability test technical field, specifically to a kind of automobile suspension spring durability test equipment and test method, comprising: detection frame, press-down detection component and bottom support component, the detection frame is used to form the vertical test space of suspension spring;The press-down detection component is set to the upper portion of the detection frame, and the press-down detection component includes lifting drive, outer ring, multiple sliding sleeves, multiple slide rods and multiple pressure heads, the outer ring is connected with the output end of lifting drive, and multiple sliding sleeves are arranged along the circumference of the outer ring.This application sets multiple independently floating pressure heads on the upper end of suspension spring, and sets the follow-up support structure composed of lifting straight rod, third spring, roller and damping adjusting assembly at the lower end, so that the upper and lower end rings can continuously maintain multi-point contact according to the height difference of spiral and local deformation in compression process, reduce the emptying of end ring, single-point extrusion and partial load.

Description

Technical Field

[0001] This invention relates to the field of spring durability testing technology, specifically to a device and method for testing the durability of automotive suspension springs. Background Technology

[0002] New energy vehicles adopt power forms such as plug-in hybrid drive, pure electric drive or fuel cell drive. The different power systems, energy storage components and energy supply components will result in different vehicle mass distribution and axle load conditions. The suspension springs need to withstand repeated compression and rebound loads according to the suspension parameters of the corresponding vehicle models. Therefore, in the process of developing the suspension system of new energy vehicles, selecting components and verifying durability, it is necessary to conduct cyclic compression tests and free rebound tests on the suspension springs to determine the stress stability and durability performance of the suspension springs under set loads, strokes and cycles.

[0003] However, the upper and lower end coils of the suspension spring extend spirally along the circumference, and there is a height difference at different circumferential positions. Existing testing equipment usually uses an integral pressure plate to compress the upper end of the spring and a flat support to support the lower end of the spring. At the beginning of the test, the pressure plate and support are prone to contacting a local position of the end coil, causing the compression load to be concentrated at a few contact positions. As the spring continues to compress, the local height and contact position of the upper and lower end coils change continuously, and the original contact positions may also become disengaged, which will cause the spring to deflect, local compression, and the test load to be distorted. In addition, existing equipment mostly uses fixed clamping or simple limiting methods for the lower end of the spring. Fixed clamping will restrict the slight rotation and local deformation of the spring during the cyclic compression process, while simple limiting is difficult to suppress the upward jump or radial movement of the spring when it rebounds freely. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the present invention provides an automotive suspension spring durability testing device and testing method, which can effectively solve the problem that the local height and contact position of the upper and lower end rings change continuously as the spring is continuously compressed.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides an automotive suspension spring durability testing device, comprising:

[0007] The test frame, the pressure testing assembly, and the bottom support assembly, wherein the test frame is used to form a vertical test space for the suspension spring;

[0008] The pressure detection component is disposed on the upper part of the detection frame. The pressure detection component includes a lifting drive component, an outer ring, multiple sliding sleeves, multiple sliding rods, and multiple pressure heads. The outer ring is connected to the output end of the lifting drive component. The multiple sliding sleeves are arranged circumferentially along the outer ring. The sliding rods are slidably disposed in the corresponding sliding sleeves. The pressure heads are disposed at the lower end of the corresponding sliding rods, so that the pressure heads can float up and down independently according to the height difference of different circumferential positions of the upper end ring of the suspension spring, and maintain follow-up contact with the upper end ring of the suspension spring when the lifting drive component reciprocates.

[0009] The bottom support assembly is located at the lower part of the detection frame. The bottom support assembly includes an annular seat, multiple lifting rods, a third spring, multiple rollers, and a damping adjustment assembly. The multiple lifting rods are arranged circumferentially along the annular seat and can float up and down relative to the annular seat. The rollers are respectively located at the upper ends of the corresponding lifting rods, so that the rollers can follow the height difference of different circumferential positions of the lower end ring of the suspension spring to provide support. The third spring is used to push the lifting rods to return to their original position. The damping adjustment assembly is used to adjust the floating resistance of the lifting rods.

[0010] Multiple pressure heads and multiple rollers respectively form corresponding floating contact supports for the suspension spring from the upper and lower end rings.

[0011] Preferably, the bottom support assembly further includes an inner support clamp and an outer ring clamp. The inner support clamp is disposed inside the lower end ring of the suspension spring, and the outer ring clamp is disposed outside the lower end ring of the suspension spring. This allows the lower end ring of the suspension spring to switch between a radially limited state and a bidirectional clamping state to adapt to controlled cyclic compression tests and free rebound tests.

[0012] Preferably, the lower end of the slide rod is provided with a cylinder and a mounting base. Both sides of the mounting base are rotatably provided with connecting rods. The connecting rods are rotatably connected to the pressure head. The telescopic end of the cylinder is rotatably connected to the pressure head, which is used to drive the pressure head to switch between a pressing position for pressing the upper end ring of the suspension spring and a yielding position for releasing the upper end constraint.

[0013] Preferably, a partition is provided inside the sliding sleeve, the sliding rod is located below the partition and is liquid-tightly slidably connected to the sliding sleeve, a second spring is provided between the sliding rod and the partition and filled with hydraulic oil, and a large one-way valve and a small one-way valve with opposite flow directions are provided inside the partition;

[0014] A pressure detection element is provided at the inner top of the sliding sleeve. Below the pressure detection element, a pressing frame, a first spring, and a pressing plate that is liquid-tightly connected to the sliding sleeve are arranged in sequence. The hydraulic oil is used to transmit the pressing reaction force of the pressing head to the pressure detection element when the sliding rod moves upward, and to form a buffer through backflow when the sliding rod resets.

[0015] Preferably, the upper end of the testing frame is provided with a support plate, the upper end of the support plate is provided with a top plate, the lifting drive is installed on the upper end of the top plate, the output end of the lifting drive passes through the top plate and is connected to a protective linkage frame, the protective linkage frame is connected to the outer ring, and is used to drive the sliding sleeve, the sliding rod and the pressure head to move vertically reciprocating synchronously.

[0016] Preferably, an annular plate is provided inside the annular seat, the lifting rods are slidably inserted through the annular plate, the lower end of each lifting rod is provided with a base plate, and the third spring is disposed between the base plate and the annular seat;

[0017] Each of the lifting rods has a mounting head at its upper end. The roller is rotatably mounted in the corresponding mounting head to reduce frictional constraint when the lower end ring of the suspension spring is compressed and rotates slightly, and to maintain follow-up support for the lower end ring.

[0018] Preferably, the damping adjustment assembly includes a magnetorheological fluid disposed within the annular seat and acting on the lifting rod, and an electromagnetic device for applying an adjustable magnetic field to the magnetorheological fluid. The electromagnetic device is used to adjust the motion resistance of the lifting rod by changing the magnetic field strength, so that the lifting rod sinks with low resistance when the suspension spring is installed, and is damped and slightly compensated vertically during durability testing.

[0019] Preferably, the inner support clamp has multiple inner clamping plates arranged circumferentially along its outer periphery, and the outer ring clamp has multiple outer clamping plates arranged circumferentially along its inner periphery. The inner clamping plates and the outer clamping plates are arranged opposite to each other to contact the inner and outer sides of the lower end ring of the suspension spring, respectively. During the controlled cyclic compression test, the inner clamping plates and the outer clamping plates form a radial limit on the lower end ring of the suspension spring. During the free rebound test, the inner clamping plates and the outer clamping plates form a bidirectional clamping on the lower end ring of the suspension spring.

[0020] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0021] First, by setting multiple independently floating pressure heads at the upper end of the suspension spring and a follow-up support structure consisting of a lifting rod, a third spring, rollers, and damping adjustment components at the lower end, the upper and lower end rings can maintain multi-point contact according to the difference in helix height and local deformation during the compression process, reducing end ring slippage, single-point compression, and off-center loading. At the same time, the inner support clamp and the outer ring clamp can switch between radial limiting state and bidirectional clamping state, enabling the equipment to take into account both controlled cyclic compression test and free rebound test, improving the stability and accuracy of suspension spring durability test.

[0022] Secondly, the cylinder can drive the pressure head to switch between the pressing position and the yielding position, which facilitates the compression loading and free rebound of the suspension spring; the hydraulic oil, large one-way valve, small one-way valve and spring in the sliding sleeve can transmit the force of the pressure head and buffer the impact of the slide rod reset; the pressure detection element can detect the force state of different pressing positions respectively; the magnetorheological fluid and electromagnetic device can adjust the movement resistance of the lifting rod; the roller can reduce the friction when the lower end ring rotates slightly; the protective plate and protective frame can reduce the risk of abnormal spring deviation or ejection. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0024] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0025] Figure 2 This is a schematic diagram of the pressure detection component of the present invention;

[0026] Figure 3 This is a cross-sectional view of the sliding sleeve of the present invention;

[0027] Figure 4 This is a schematic diagram of the pressure head of the present invention;

[0028] Figure 5 This is a schematic diagram of the bottom support component of the present invention;

[0029] Figure 6 This is a schematic diagram of the structure of the annular seat of the present invention;

[0030] Figure 7 This is a schematic diagram of the lifting rod of the present invention.

[0031] Reference numerals: 1. Detection frame; 101. Arc-shaped plate; 102. Protective plate; 103. Protective frame; 2. Downward pressure detection assembly; 201. Support plate; 202. Top plate; 203. Lifting drive component; 204. Protective linkage frame; 205. Outer ring; 206. Sliding sleeve; 207. Pressure detection element; 208. Extrusion frame; 209. First spring; 210. Extrusion plate; 211. Slide rod; 212. 213. Second spring; 214. Partition plate; 215. Cylinder; 216. Mounting seat; 217. Linkage rod; 218. Pressure head; 3. Bottom support assembly; 301. Inner support clamp; 302. Inner clamping plate; 303. Outer ring clamp; 304. Outer clamping plate; 305. Annular seat; 306. Annular plate; 307. Lifting rod; 308. Base plate; 309. Third spring; 310. Mounting head; 311. Roller. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention 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 the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to embodiments.

[0034] Example: Refer to Figures 1 to 7 An automotive suspension spring durability testing device, comprising:

[0035] The test frame 1, the pressure test assembly 2, and the bottom support assembly 3 are used to form a vertical test space for the suspension spring.

[0036] The pressure detection component 2 is set on the upper part of the detection frame 1. The pressure detection component 2 includes a lifting drive component 203, an outer ring 205, multiple sliding sleeves 206, multiple sliding rods 211, and multiple pressure heads 217. The floating stroke of the pressure head 217 is greater than the maximum height difference of the upper end ring of the spring to be tested. The outer ring 205 is connected to the output end of the lifting drive component 203. Multiple sliding sleeves 206 are arranged circumferentially along the outer ring 205. The sliding rods 211 are slidably set in the corresponding sliding sleeves 206. The pressure heads 217 are respectively set at the lower end of the corresponding sliding rods 211, so that the pressure heads 217 can float up and down independently with the height difference of different circumferential positions of the upper end ring of the suspension spring, and maintain follow-up contact with the upper end ring of the suspension spring when the lifting drive component 203 reciprocates.

[0037] The bottom support assembly 3 is located at the lower part of the detection frame 1. The bottom support assembly 3 includes an annular seat 305, multiple lifting rods 307, a third spring 309, multiple rollers 311, and a damping adjustment assembly. The multiple lifting rods 307 are arranged circumferentially along the annular seat 305 and can float up and down relative to the annular seat 305. The rollers 311 are respectively located at the upper end of the corresponding lifting rods 307, so that the rollers 311 can follow the height difference of different circumferential positions of the lower end ring of the suspension spring to provide support. The third spring 309 is used to push the lifting rods 307 to reset upward. The damping adjustment assembly is used to adjust the floating resistance of the lifting rods 307.

[0038] Among them, multiple pressure heads 217 and multiple rollers 311 respectively form corresponding floating contact supports for the suspension spring from the upper and lower end rings.

[0039] The bottom support assembly 3 also includes an inner support clamp 301 and an outer ring clamp 303. The inner support clamp 301 is located inside the lower end ring of the suspension spring, and the outer ring clamp 303 is located outside the lower end ring of the suspension spring. It is used to switch the lower end ring of the suspension spring between a radial limiting state and a bidirectional clamping state to adapt to controlled cyclic compression test and free rebound test.

[0040] The lower end of the slide bar 211 is provided with a cylinder 214 and a mounting base 215. Both sides of the mounting base 215 are rotatably provided with connecting rods 216. The connecting rods 216 are rotatably connected to the pressure head 217. The telescopic end of the cylinder 214 is rotatably connected to the pressure head 217, which is used to drive the pressure head 217 to switch between the pressing position for pressing the upper end ring of the suspension spring and the yielding position for releasing the upper end constraint.

[0041] A partition 213 is provided inside the sliding sleeve 206. A sliding rod 211 is located below the partition 213 and is liquid-tightly slidably connected to the sliding sleeve 206. A second spring 212 is provided between the sliding rod 211 and the partition 213 and filled with hydraulic oil. A large one-way valve and a small one-way valve with opposite flow directions are provided inside the partition 213; the flow area of ​​the large one-way valve is larger than that of the small one-way valve. A pressure detection element 207 is provided at the inner top of the sliding sleeve 206. The pressure detection element 207 is used to detect the pressing load of the corresponding pressure head 217 on the upper end ring of the suspension spring. It is preferably a miniature pressure weighing sensor, button-type pressure sensor or strain gauge pressure sensor. The detection range of the pressure detection element 207 should be greater than the maximum reaction force that a single pressure head 217 bears during the test. The pressure detection element 207 converts the mechanical pressure into an electrical signal and transmits the electrical signal. The force value of the corresponding pressure head 217 is obtained by connecting to an existing signal amplifier, data acquisition unit or display instrument. Below the pressure detection element 207, there is a compression frame 208, a first spring 209 and a compression plate 210 that is liquid-tightly connected to the sliding sleeve 206. The hydraulic oil pushes the compression plate 210 to transmit pressure to the pressure detection element 207 through the large one-way valve, and flows back through the small one-way valve to buffer the reset of the slide rod 211. Multiple pressure detection elements 207 correspond to multiple pressure heads 217, which can detect the force at different circumferential positions of the upper coil of the suspension spring. By comparing the detection results of multiple pressure detection elements 207, it is possible to find that some pressure heads 217 are subjected to excessive force, insufficient force or not in full contact with the upper coil of the suspension spring. This facilitates the elimination of invalid tests caused by spring misalignment or contact gaps, and improves the comparability of test results of different batches of suspension springs.

[0042] A pressure detection element 207 is provided at the inner top of the sliding sleeve 206. Below the pressure detection element 207, a pressing frame 208, a first spring 209, and a pressing plate 210 that is liquid-tightly slidably connected to the sliding sleeve 206 are arranged in sequence. The hydraulic oil is used to transmit the pressing reaction force of the pressing head 217 to the pressure detection element 207 when the sliding rod 211 moves upward, and to form a buffer through backflow when the sliding rod 211 resets.

[0043] The upper end of the testing frame 1 is provided with a support plate 201, and the upper end of the support plate 201 is provided with a top plate 202. The lifting drive component 203 is installed on the upper end of the top plate 202. The output end of the lifting drive component 203 passes through the top plate 202 and is connected to a protective linkage frame 204. The protective linkage frame 204 is connected to an outer ring 205 and is used to drive the sliding sleeve 206, the sliding rod 211 and the pressure head 217 to move vertically and reciprocally synchronously.

[0044] An annular plate 306 is provided inside the annular seat 305, and lifting rods 307 are slidably inserted through the annular plate 306. The lower end of each lifting rod 307 is provided with a base plate 308, and a third spring 309 is provided between the base plate 308 and the annular seat 305.

[0045] Each lifting rod 307 has an mounting head 310 at its upper end. Rollers 311 are rotatably mounted in the corresponding mounting head 310 to reduce frictional constraints when the lower end ring of the suspension spring is compressed and rotates slightly, and to maintain follow-up support for the lower end ring.

[0046] The damping adjustment assembly includes a magnetorheological fluid disposed within the annular seat 305 and acting on the lifting rod 307, and an electromagnetic device for applying an adjustable magnetic field to the magnetorheological fluid. The electromagnetic device is used to adjust the motion resistance of the lifting rod 307 by changing the magnetic field strength, so that the lifting rod 307 sinks with low resistance when the suspension spring is installed, and is damped and slightly compensated vertically during durability testing. Multiple rollers 311 can rise and fall independently with the corresponding lifting rod 307, and under the action of the third spring 309, they maintain an upward tendency to approach the lower end ring of the suspension spring, so that the multiple rollers 311 can continue to compensate for the local height change of the lower end ring during the compression of the suspension spring. The rollers 311 can rotate relative to the mounting head 310, which can reduce the frictional resistance generated when the lower end ring rotates slightly, reduce the additional torsional constraint of the fixed support on the suspension spring, and make the test state closer to the actual stress state of the suspension spring.

[0047] The inner support clamp 301 has multiple inner clamping plates 302 arranged circumferentially along its outer periphery, and the outer ring clamp 303 has multiple outer clamping plates 304 arranged circumferentially along its inner periphery. The inner clamping plates 302 and outer clamping plates 304 are arranged opposite to each other to contact the inner and outer sides of the lower end ring of the suspension spring, respectively. During the controlled cyclic compression test, the inner clamping plates 302 and outer clamping plates 304 form a radial limit on the lower end ring of the suspension spring. During the free rebound test, the inner clamping plates 302 and outer clamping plates 304 form a bidirectional clamping on the lower end ring of the suspension spring. The inner support clamp 301 adopts the existing... Some pneumatic internal expansion clamps or pneumatic internal support chucks are used. The internal support clamp 301 is equipped with a small cylinder, a conical drive component and multiple radial sliding components. When the small cylinder pushes the conical drive component to move axially, the conical drive component drives multiple radial sliding components to move outward synchronously, so that the inner clamping plate 302 installed on the radial sliding components is close to the inner side of the lower end ring of the suspension spring. When the small cylinder is reset, the multiple inner clamping plates 302 retract inward synchronously.

[0048] The outer ring clamp 303 is used with existing pneumatic inner circle clamping clamps, hydraulic inner circle clamping clamps or multi-jaw self-centering clamps. The outer ring clamp 303 is equipped with an annular drive and multiple radial sliders. When the annular drive is activated, it drives the multiple radial sliders to move inward or outward synchronously, so that the outer clamping plate 304 installed on the radial sliders moves closer to or further away from the outer side of the lower end ring of the suspension spring.

[0049] The working principle of this invention is as follows:

[0050] Before the test begins, the operator needs to determine the compression stroke, compression load, operating speed and number of cycles of the suspension spring based on the axle load, suspension structure, installation position of the suspension spring and the specified durability test conditions of the new energy vehicle to be tested. Then, the suspension spring to be tested is placed in the test frame 1 and the lower end ring of the suspension spring is supported by the bottom support component 3.

[0051] During the controlled cyclic compression test, the lifting drive component 203 drives multiple pressure heads 217 to move back and forth according to the specified compression stroke, running speed and number of cycles of the suspension spring of the new energy vehicle under test, so that the suspension spring is repeatedly compressed and controlled to rebound under the set test conditions, in order to simulate the working state of the suspension spring of the new energy vehicle when it continuously bears the vertical load change during the vehicle driving process.

[0052] Before the test begins, the lifting drive component 203 is in a retracted state. The protective linkage frame 204, outer ring 205, sliding sleeve 206 and pressure head 217 are located in the upper position inside the test frame 1. The cylinder 214 drives the pressure head 217 to rotate to the clearance position to prevent the pressure head 217 from obstructing the placement of the suspension spring. The inner support clamp 301 drives the inner clamp plate 302 to retract towards the center of the inner support clamp 301. The outer ring clamp 303 drives the outer clamp plate 304 to move away from the inner support clamp 301, so that an installation space larger than the lower coil diameter of the suspension spring is formed between the inner clamp plate 302 and the outer clamp plate 304.

[0053] The operator opens the protective plate 102, places the suspension spring to be tested into the bottom support assembly 3 along the test area of ​​the test frame 1, and positions the lower end of the suspension spring between the inner support clamp 301 and the outer ring clamp 303. After the suspension spring is placed, the protective plate 102 closes the test area between the arc plate 101 and the test frame 1. The protective frame 103 protects the outer periphery of the suspension spring to reduce the risk of the suspension spring detaching from the test frame 1 when it breaks, shifts, or jumps abnormally during the test.

[0054] After the suspension spring is placed into the bottom support assembly 3, its lower end ring first contacts the multiple rollers 311 set in the annular seat 305. During the initial placement stage of the suspension spring, the electromagnetic device acting on the magnetorheological fluid is in a de-energized or low magnetic field state, and the movement resistance generated by the magnetorheological fluid on the lifting rods 307 is small. Each lifting rod 307 can move independently vertically relative to the annular plate 306. Since the lower end ring of the suspension spring is helical, there is a difference in height at different circumferential positions. Some rollers 311 will contact the lower end ring of the suspension spring first. Under the action of the weight of the suspension spring and the pressure of the end ring, the rollers 311 that contact first drive the corresponding mounting head 3. 10. The lifting rod 307 and the base plate 308 move downward and compress the corresponding third spring 309; the remaining rollers 311 continue to move downward as the suspension spring moves and contact the lower end ring in sequence. When the suspension spring is fully placed in place, each lifting rod 307 produces a different amplitude of downward displacement according to the height of the corresponding end ring position, so that multiple rollers 311 form a non-equal height multi-point support state that matches the spiral contour of the lower end ring of the suspension spring. Multiple rollers 311 jointly support the lower end ring of the suspension spring, which can avoid the lower end ring of the suspension spring only contacting the plane support surface at the lowest local position, and reduce the situation of single-point pressure, local compression and initial deflection of the lower end ring.

[0055] After the suspension spring completes its initial support, the inner support clamp 301 drives multiple inner clamping plates 302 to move radially outward, and the outer ring clamp 303 drives multiple outer clamping plates 304 to move radially inward. The inner clamping plates 302 are used to limit the movement from the inside of the lower end ring of the suspension spring, and the outer clamping plates 304 are used to limit the movement from the outside of the lower end ring of the suspension spring. The operator adjusts the stroke and clamping pressure of the inner support clamp 301 and the outer ring clamp 303 according to the test mode required, so that the inner clamping plates 302 and the outer clamping plates 304 are in a radially limited state or a bidirectional clamping state.

[0056] During controlled cyclic compression testing, the inner support clamp 301 and the outer ring clamp 303 drive the inner clamping plate 302 and the outer clamping plate 304 close to the lower end ring of the suspension spring with small strokes, respectively. The inner clamping plate 302 and the outer clamping plate 304 maintain a small gap with the lower end ring of the suspension spring, and can also use low clamping pressure to fit the inner and outer sides of the lower end ring of the suspension spring, respectively. In this state, the inner clamping plate 302 and the outer clamping plate 304 are mainly used to limit the excessive radial movement of the lower end ring of the suspension spring, without rigidly clamping the lower end ring of the suspension spring, so that the lower end ring of the suspension spring can still produce necessary micro-rotation, radial adjustment and local deformation during compression.

[0057] Before the controlled cyclic compression test begins, the electromagnetic device applies a magnetic field of predetermined intensity to the magnetorheological fluid. Under the action of the magnetic field, the magnetorheological fluid increases the resistance to the vertical movement of the lifting rods 307, so that the multiple lifting rods 307 maintain the basic support height after completing the initial conformal. The magnetic field intensity applied by the electromagnetic device does not completely lock the lifting rods 307. When the lower end ring of the suspension spring undergoes a local height change during the subsequent compression process, each lifting rod 307 can still make a small vertical movement under the combined action of the pressure of the corresponding end ring and the third spring 309.

[0058] When a certain circumferential position of the lower end ring of the suspension spring moves downward, this position pushes the corresponding roller 311, mounting head 310, and lifting rod 307 to overcome the motion resistance of the magnetorheological fluid and move downward slightly, further compressing the third spring 309. When a certain circumferential position of the lower end ring of the suspension spring moves upward and tends to separate from the corresponding roller 311, the compressed third spring 309 pushes the lifting rod 307 upward slightly through the base plate 308, so that the roller 311 follows the height change of the lower end ring of the suspension spring to compensate upward. The magnetorheological fluid is used to suppress the lifting rod 307 from moving too fast or too large. The third spring 309 is used to keep the roller 311 tending to move upward closer to the lower end ring of the suspension spring. The two cooperate with each other so that multiple rollers 311 can continuously compensate for the local gap caused by the compression deformation of the lower end ring while maintaining the basic support height of the lower end of the suspension spring.

[0059] The roller 311 can rotate relative to the mounting head 310. When the lower end ring of the suspension spring undergoes a slight circumferential rotation or radial adjustment during compression, the roller 311 reduces the frictional resistance between itself and the lower end ring of the suspension spring by rotating, thereby preventing the lower end ring of the suspension spring from being rigidly stuck in the fixed support position and reducing the additional lateral force generated by the stuck position.

[0060] After the lower end of the suspension spring is positioned and supported, the cylinder 214 drives the pressure head 217 to rotate to the pressing position. The telescopic end of the cylinder 214 is rotatably connected to the pressure head 217. The connecting rods 216 on both sides of the mounting base 215 are rotatably connected to the pressure head 217. When the cylinder 214 extends and retracts, the telescopic end of the cylinder 214 and the connecting rods 216 together restrict and guide the pressure head 217 to rotate, so that the pressure head 217 can switch between the pressing position and the yielding position. After the pressure head 217 rotates to the pressing position, the lifting drive component 203 drives the protective linkage frame 204 to move downward. The protective linkage frame 204 drives the outer ring 205 and the multiple sliding sleeves 206 arranged in a circumferential array on the outer ring 205 to move downward synchronously, so that the multiple pressure heads 217 gradually approach the upper end ring of the suspension spring.

[0061] Because the upper coil of the suspension spring is also helical, with different heights at different circumferential positions, the multiple pressure heads 217 will not contact the upper coil of the suspension spring simultaneously. The pressure head 217 located at the higher coil position contacts the upper coil of the suspension spring first. After receiving the reaction force from the coil, this pressure head 217 drives the corresponding sliding rod 211 to move upward relative to the sliding sleeve 206. The pressure head 217 located at the lower coil position continues to move downward with the outer ring 205 until it contacts the corresponding coil position. The multiple sliding rods 211 generate different amplitude floating displacements according to the height difference of different circumferential positions of the upper coil of the suspension spring, so that the multiple pressure heads 217 form a non-uniform height multi-point pressing contact adapted to the upper coil of the suspension spring. State; When the slide bar 211 moves upward, the slide bar 211 compresses the second spring 212 located between the slide bar 211 and the partition plate 213, and pushes the hydraulic oil located between the slide bar 211 and the partition plate 213 into the space between the partition plate 213 and the extrusion plate 210 through the large one-way valve in the partition plate 213. The hydraulic oil entering the space pushes the extrusion plate 210 to move upward, and the extrusion plate 210 compresses the first spring 209. The first spring 209 transmits pressure to the pressure detection element 207 through the extrusion frame 208. The pressure detection element 207 obtains the pressure receiving condition of the corresponding pressure head 217 according to the pressure received, thereby detecting the force state of different circumferential positions of the upper coil of the suspension spring respectively.

[0062] As the lifting drive component 203 continues to drive the multiple sliding sleeves 206 downwards, the multiple pressure heads 217 jointly apply a compressive load to the upper end ring of the suspension spring. When the suspension spring is compressed, the height relationship of different circumferential positions of its upper end ring will change with the deformation of the end ring. Each sliding rod 211 can move vertically independently relative to the corresponding sliding sleeve 206. The second spring 212 continuously makes the sliding rod 211 tend to extend downwards. When a certain position of the upper end ring of the suspension spring is lowered and tends to separate from the corresponding pressure head 217, the second spring 212 pushes the sliding rod 211 and the pressure head 217 downwards to compensate. When a certain position is raised, that position pushes the corresponding pressure head 217 and the sliding rod 211 upwards to retract. The multiple pressure heads 217 thus continuously adhere to the upper end ring of the suspension spring, reducing single-point compression and local load concentration caused by the pressure head 217 disengaging.

[0063] In the controlled cyclic compression test mode, the lifting drive component 203 reciprocates according to the set compression stroke, running speed, and cycle frequency. When the lifting drive component 203 moves downward, multiple pressure heads 217 compress the suspension spring together; when the lifting drive component 203 moves upward, the multiple pressure heads 217 remain in contact with the upper coil of the suspension spring, and the suspension spring rebounds in a controlled manner as the pressure heads 217 move upward. This test mode is used to detect the durability performance of the suspension spring under a set compression speed and a set cycle stroke. In this mode, the inner clamping plate 302 and the outer clamping plate 304 are in a radially limited state, and multiple rollers 3 11 is in a damped follow-up support state to allow the lower end ring of the suspension spring to make necessary minor adjustments during the controlled cyclic compression process; when the pressure head 217 moves upward with the lifting drive component 203, the slide rod 211 tends to return downward under the elastic force of the second spring 212. The hydraulic oil between the partition plate 213 and the extrusion plate 210 flows back to the space between the slide rod 211 and the partition plate 213 through the small one-way valve in the partition plate 213. The flow capacity of the small one-way valve is smaller than that of the large one-way valve, so that the return process of the hydraulic oil has a certain damping, thereby reducing the rapid reset impact of the slide rod 211 and the pressure head 217.

[0064] When a free rebound test is required, the inner support clamp 301 and the outer ring clamp 303 first switch from the radial limiting state to the bidirectional clamping state. The inner support clamp 301 drives multiple inner clamping plates 302 to move outward, so that the multiple inner clamping plates 302 contact the inner side of the lower end ring of the suspension spring respectively. The outer ring clamp 303 drives multiple outer clamping plates 304 to move inward, so that the multiple outer clamping plates 304 contact the outer side of the lower end ring of the suspension spring respectively. The multiple inner clamping plates 302 and the multiple outer clamping plates 304 jointly apply clamping force from the inner and outer sides of the lower end ring of the suspension spring, keeping the lower end ring of the suspension spring within the support area of ​​the bottom support component 3.

[0065] The clamping force applied by the inner clamping plate 302 and the outer clamping plate 304 to the lower end ring of the suspension spring is such that it can limit the overall upward jump and radial movement of the suspension spring, so as to avoid excessive clamping force and cause obvious deformation of the lower end ring of the suspension spring. Since the inner clamping plate 302 and the outer clamping plate 304 are arranged in the circumferential direction, the lower end ring of the suspension spring can obtain relatively uniform bidirectional clamping from the inside and outside, reducing the eccentric constraint caused by clamping from only one side.

[0066] After the inner clamping plate 302 and the outer clamping plate 304 complete the bidirectional clamping, the electromagnetic device increases the magnetic field strength applied to the magnetorheological fluid, which further increases the motion resistance of the magnetorheological fluid to the lifting rod 307, so as to improve the support stability of multiple rollers 311 during the free rebound of the suspension spring. The magnetorheological fluid still allows the lifting rod 307 to undergo small-amplitude compensation under the action of the third spring 309, thereby avoiding the lower end ring of the suspension spring from forming a significant gap with some rollers 311 due to local height changes during the rebound process.

[0067] After the lifting drive component 203 drives multiple pressure heads 217 to compress the suspension spring to a set position, the cylinder 214 quickly drives the pressure head 217 to rotate from the pressing position to the yielding position. Alternatively, the lifting drive component 203 drives the protective linkage frame 204, the outer ring 205, the sliding sleeve 206 and the pressure head 217 to move upward as a whole, so that the multiple pressure heads 217 separate from the upper end ring of the suspension spring. After the upper end ring of the suspension spring is freed from the constraint of the multiple pressure heads 217, the suspension spring rebounds freely upward by its own elasticity.

[0068] In the free rebound test, "free rebound" refers to the suspension spring rebounding according to its own elastic characteristics after the upper end of the suspension spring is released from the following restriction of the pressure head 217. The lower end of the suspension spring is still held bidirectionally by the inner clamping plate 302 and the outer clamping plate 304, and supported at multiple points by multiple rollers 311. This fixed boundary can prevent the suspension spring from flying upward, jumping or detaching from the bottom support component 3 after the upper end is suddenly released, while not restricting the free recovery process of the upper end of the suspension spring.

[0069] During the free rebound of the suspension spring, the lower coil may experience local height changes and slight rotation. Each third spring 309 pushes the corresponding lifting rod 307 and roller 311 to perform small-amplitude vertical compensation following the lower coil. The magnetorheological fluid dampens and buffers the movement of the lifting rod 307. The roller 311 reduces the frictional resistance generated by the slight rotation of the lower coil by rotating. The inner clamping plate 302 and the outer clamping plate 304 maintain the clamping of the lower coil of the suspension spring, and the multiple rollers 311 maintain the support of the lower coil, enabling the suspension spring to complete the free rebound of the upper end under the condition of stability at the lower end.

[0070] After the suspension spring completes its free rebound, the suspension spring's free height, permanent deformation, appearance, and load change during recompression are tested according to the specified number of tests to evaluate its durability. When conducting the next free rebound test, cylinder 214 drives pressure head 217 to rotate to the pressing position again, and lifting drive component 203 drives multiple pressure heads 217 to compress the suspension spring again. Then, the clamping confirmation and release process is repeated.

[0071] After the test, the lifting drive component 203 drives the protective linkage frame 204, outer ring 205, sliding sleeve 206 and pressure head 217 back to the initial position. The cylinder 214 drives the pressure head 217 to rotate to the clearance position. The electromagnetic device stops applying a magnetic field to the magnetorheological fluid, reducing the resistance of the magnetorheological fluid to the movement of the lifting rod 307. The inner support clamp 301 drives the inner clamp plate 302 to retract inward, and the outer ring clamp 303 drives the outer clamp plate 304 to move outward, releasing the clamp on the lower end ring of the suspension spring. The operator opens the protective plate 102 and removes the suspension spring from the test frame 1. After the suspension spring is removed, each third spring 309 pushes the corresponding lifting rod 307 and roller 311 upward to reset, so that the bottom support component 3 returns to the state of being ready to support.

[0072] A test method for an automotive suspension spring durability testing device includes the following steps:

[0073] S1. Place the suspension spring to be tested in the test frame 1, so that the lower end of the suspension spring rests on the bottom support assembly 3 and contacts multiple rollers 311.

[0074] S2. When the damping adjustment component is in a low-resistance state, the lower end ring of the suspension spring pushes the corresponding lifting rod 307 up and down along the circumferential height difference. The third spring 309 pushes the lifting rod 307 to reset, so that multiple rollers 311 form a conformal support for the lower end ring of the suspension spring.

[0075] S3, the lifting drive component 203 drives the outer ring 205 to move down, and the outer ring 205 drives multiple sliding sleeves 206, sliding rods 211 and pressure heads 217 to approach the upper end ring of the suspension spring; the multiple pressure heads 217 float independently according to the height difference of different positions of the upper end ring, and form multiple points of contact with the upper end ring of the suspension spring.

[0076] S4. The lifting drive component 203 drives the pressure detection component 2 to reciprocate according to the set stroke, so that the suspension spring can undergo a durability compression test. During the test, multiple pressure heads 217 continuously press against the upper end ring of the suspension spring, and multiple rollers 311 support the lower end ring of the suspension spring. The damping adjustment component adjusts the floating resistance of the lifting rod 307 to reduce end ring slippage and off-center loading.

[0077] S5. After the test, the lifting drive component 203 drives the outer ring 205 to move upward and reset, the pressure head 217 separates from the upper end ring of the suspension spring, the third spring 309 pushes the lifting rod 307 and the roller 311 to reset, and the suspension spring is removed.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for testing the durability of automotive suspension springs, characterized in that, include: The test frame (1), the pressure test assembly (2), and the bottom support assembly (3) are provided, wherein the test frame (1) is used to form a vertical test space for the suspension spring; The pressure detection component (2) is disposed on the upper part of the detection frame (1). The pressure detection component (2) includes a lifting drive (203), an outer ring (205), multiple sliding sleeves (206), multiple sliding rods (211), and multiple pressure heads (217). The outer ring (205) is connected to the output end of the lifting drive (203). The multiple sliding sleeves (206) are arranged circumferentially along the outer ring (205). The sliding rods (211) are respectively slidably disposed in the corresponding sliding sleeves (206). The pressure heads (217) are respectively disposed at the lower end of the corresponding sliding rods (211), so that the pressure heads (217) can float up and down independently with the height difference of different circumferential positions of the upper end ring of the suspension spring, and maintain follow-up contact with the upper end ring of the suspension spring when the lifting drive (203) reciprocates. The bottom support assembly (3) is located at the lower part of the detection frame (1). The bottom support assembly (3) includes an annular seat (305), multiple lifting rods (307), a third spring (309), multiple rollers (311), and a damping adjustment assembly. The multiple lifting rods (307) are arranged circumferentially along the annular seat (305) and can float up and down relative to the annular seat (305). The rollers (311) are respectively located at the upper end of the corresponding lifting rods (307), so that the rollers (311) can follow the height difference of different circumferential positions of the lower end of the suspension spring to provide support. The third spring (309) is used to push the lifting rods (307) to reset upward. The damping adjustment assembly is used to adjust the floating resistance of the lifting rods (307). Among them, multiple pressure heads (217) and multiple rollers (311) respectively form corresponding floating contact supports for the suspension spring from the upper and lower end rings.

2. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, The bottom support assembly (3) further includes an inner support clamp (301) and an outer ring clamp (303). The inner support clamp (301) is located inside the lower end ring of the suspension spring, and the outer ring clamp (303) is located outside the lower end ring of the suspension spring. It is used to switch the lower end ring of the suspension spring between a radial limiting state and a bidirectional clamping state to adapt to controlled cyclic compression test and free rebound test.

3. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, The lower end of the slide rod (211) is provided with a cylinder (214) and a mounting base (215). Both sides of the mounting base (215) are rotatably provided with connecting rods (216). The connecting rods (216) are rotatably connected to the pressure head (217). The telescopic end of the cylinder (214) is rotatably connected to the pressure head (217) to drive the pressure head (217) to switch between a pressing position for pressing the upper end ring of the suspension spring and a yielding position for releasing the upper end constraint.

4. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, A partition (213) is provided inside the sliding sleeve (206). The sliding rod (211) is located below the partition (213) and is liquid-tightly slidably connected to the sliding sleeve (206). A second spring (212) is provided between the sliding rod (211) and the partition (213) and is filled with hydraulic oil. A large check valve and a small check valve with opposite flow directions are provided inside the partition (213). The inner top of the sliding sleeve (206) is provided with a pressure detection element (207). Below the pressure detection element (207) are arranged a pressing frame (208), a first spring (209), and a pressing plate (210) that is liquid-tightly slidably connected to the sliding sleeve (206). The hydraulic oil is used to transmit the pressing reaction force of the pressing head (217) to the pressure detection element (207) when the sliding rod (211) moves upward, and to form a buffer through backflow when the sliding rod (211) resets.

5. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, The upper end of the testing frame (1) is provided with a support plate (201), and the upper end of the support plate (201) is provided with a top plate (202). The lifting drive (203) is installed on the upper end of the top plate (202). The output end of the lifting drive (203) passes through the top plate (202) and is connected to a protective linkage frame (204). The protective linkage frame (204) is connected to the outer ring (205) and is used to drive the sliding sleeve (206), the sliding rod (211) and the pressure head (217) to move vertically reciprocally in sync.

6. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, An annular plate (306) is provided inside the annular seat (305), and the lifting rods (307) are slidably inserted through the annular plate (306). The lower end of each lifting rod (307) is provided with a base plate (308), and the third spring (309) is provided between the base plate (308) and the annular seat (305). Each of the lifting rods (307) has an mounting head (310) at its upper end. The roller (311) is rotatably mounted in the corresponding mounting head (310) to reduce friction constraint when the lower end ring of the suspension spring is compressed and rotates slightly, and to maintain follow-up support for the lower end ring.

7. The automotive suspension spring durability testing equipment according to claim 1, characterized in that, The damping adjustment assembly includes a magnetorheological fluid disposed within the annular seat (305) and acting on the lifting rod (307), and an electromagnetic device for applying an adjustable magnetic field to the magnetorheological fluid. The electromagnetic device is used to adjust the motion resistance of the lifting rod (307) by changing the magnetic field strength, so that the lifting rod (307) sinks with low resistance when the suspension spring is installed, and is damped and slightly compensated vertically during durability testing.

8. The automobile suspension spring durability testing equipment according to claim 2, characterized in that, The inner support clamp (301) has multiple inner clamping plates (302) arranged circumferentially on its outer periphery, and the outer ring clamp (303) has multiple outer clamping plates (304) arranged circumferentially on its inner periphery. The inner clamping plates (302) and the outer clamping plates (304) are arranged opposite to each other and are used to contact the inner and outer sides of the lower end ring of the suspension spring, respectively. During the controlled cyclic compression test, the inner clamping plates (302) and the outer clamping plates (304) form a radial limit on the lower end ring of the suspension spring. During the free rebound test, the inner clamping plates (302) and the outer clamping plates (304) form a bidirectional clamping on the lower end ring of the suspension spring.

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