Friction test device for shock absorber

Abstract

The invention discloses a shock absorber friction force test device, and relates to the technical field of shock absorber testing. The three-degree-of-freedom platform is used for driving the workbench to move along the X axis, move along the Y axis and rotate around the Z axis; the suspension mechanism comprises an installation frame, a shock absorber, a swing arm assembly and wheels. The mounting frame is arranged on the workbench; one end of the damper is connected with the swing arm assembly, and the other end of the damper is connected with the mounting rack; a displacement sensor and a force sensor are arranged on the shock absorber; the driving mechanism is used for driving the wheels to rotate; the bearing assembly is used for bearing wheels; the vibration mechanism is arranged on the rack and used for driving the bearing platform to vibrate up and down; and a processor. The damper friction force testing device can effectively simulate the state of the damper in the real working condition, and then the displacement sensor and the force sensor are used for recording the excitation speed and the damping force of the damper respectively, so that the friction force borne by the damper in the real working condition can be analyzed.

Description

Technical Field

[0001] The invention relates to the technical field of shock absorber testing, and in particular to a shock absorber friction force testing device. Background Art

[0002] Shock absorbers are widely used in automobiles. Shock absorbers can suppress the shock caused by the rebound of the spring after shock absorption and the impact from the road surface to improve the driving smoothness of the car. Shock absorbers need to be tested for friction before they are put on the market. In the prior art, technicians usually use test equipment to apply vibration parallel to the axis of the shock absorber to the shock absorber, and apply lateral force perpendicular to the axis of the shock absorber to the shock absorber to detect the friction of the shock absorber. However, in the actual driving process of the car, the working condition of the shock absorber is relatively complicated. In addition to its own axial expansion and contraction deformation, the shock absorber may also experience deflection deformation and other phenomena.

[0003] The test device in the prior art cannot test the friction force that the shock absorber is subjected to in real working conditions. Summary of the invention

[0004] The main purpose of the present invention is to provide a vibration damper friction test device, aiming to solve the technical problem that the test device in the prior art cannot test the friction condition of the vibration damper in the actual working condition.

[0005] To achieve the above object, the present invention provides a vibration damper friction test device, comprising:

[0006] frame;

[0007] A three-degree-of-freedom platform, one end of which is arranged on the frame, and the other end of which is provided with a workbench; the three-degree-of-freedom platform is used to drive the workbench to move along the X-axis, move along the Y-axis, and rotate around the Z-axis;

[0008] The suspension mechanism comprises a mounting frame, a shock absorber, a swing arm assembly and a wheel; the mounting frame is arranged on the workbench; one end of the swing arm assembly is connected to the mounting frame, and the other end of the swing arm assembly is rotatably connected to the wheel; one end of the shock absorber is connected to the swing arm assembly, and the other end of the shock absorber is connected to the mounting frame; a displacement sensor and a force sensor are arranged on the shock absorber; the displacement sensor is used to detect the excitation speed of the shock absorber; and the force sensor is used to detect the damping force applied to the shock absorber;

[0009] A driving mechanism, disposed on the frame and used to drive the wheel to rotate;

[0010] The bearing assembly comprises a bearing platform and a plurality of rotating rollers rotatably connected to the bearing platform; wherein the wheels abut against the rotating rollers;

[0011] A vibration mechanism, which is arranged on the frame and is used to drive the bearing platform to vibrate up and down;

[0012] A processor, the three-degree-of-freedom platform, the driving mechanism, the displacement sensor, the force sensor and the vibration mechanism are all electrically connected to the processor.

[0013] Optionally, based on the excitation speed of the shock absorber, a friction algorithm is used to calculate the mechanical damping force of the shock absorber, and the mechanical damping force is:

[0014] F p =f c sgn(v0)+c m v0;

[0015] Among them, F p represents the mechanical damping force, f c is the Coulomb friction force, c m represents the viscous term of mechanical damping, sgn represents the sign function, and v0 represents the excitation velocity of the shock absorber.

[0016] Optionally, the shock absorber includes a first cylinder, a second cylinder, a shock absorbing spring, a screw rod, a transmission unit and a generator;

[0017] One end of the first cylinder is connected to the mounting frame, and the other end of the first cylinder is slidably sleeved in the second cylinder; a positioning block is provided on the outer side of the second cylinder; one end of the second cylinder away from the first cylinder is connected to the swing arm assembly; the damping spring is sleeved on the outer side of the first cylinder, one end of the damping spring abuts against the first cylinder, and the other end of the damping spring abuts against the positioning block;

[0018] One end of the screw extends into the first cylinder and is threadedly connected to the first cylinder, and the other end of the screw is transmission-connected to the transmission unit; the transmission unit is used to convert both forward and reverse rotation of the screw into forward rotation of the shaft of the generator, and the forward rotation state of the generator is the power generation state.

[0019] Optionally, the transmission unit includes a first bevel gear, a second bevel gear, a third bevel gear, a first one-way bearing and a second one-way bearing;

[0020] A shell is provided at one end of the second cylinder away from the first cylinder, and the transmission unit is located in the inner cavity of the shell; the first bevel gear and the second bevel gear are both connected to the screw in driving manner, the first one-way bearing is provided between the first bevel gear and the screw, and the second one-way bearing is provided between the second bevel gear and the screw; the first bevel gear and the second bevel gear are both meshed with the third bevel gear, and the third bevel gear is fixed on the rotating shaft of the generator; when the screw rotates forward, the first bevel gear rotates with the screw, and the second bevel gear remains stationary; when the screw rotates reversely, the first bevel gear remains stationary, and the second bevel gear rotates with the screw.

[0021] Optionally, it also includes a side-pressure telescopic rod; one end of the side-pressure telescopic rod is arranged on the frame, and the other end of the side-pressure telescopic rod abuts against the outer side wall of the second cylinder; the side-pressure telescopic rod is electrically connected to the processor.

[0022] Optionally, it also includes a battery and a rectifier; the generator, the rectifier and the battery are electrically connected in sequence; and the battery is electrically connected to the processor.

[0023] Optionally, the three-degree-of-freedom platform includes a mounting plate and three electric push rods; the mounting plate is arranged on the frame; one end of each electric push rod is rotatably connected to the mounting plate, and the other end of the electric push rod is rotatably connected to the workbench; the electric push rod is electrically connected to the processor.

[0024] Optionally, the workbench is provided with a connecting piece extending along the vibration direction of the vibration mechanism, the connecting piece is provided with a plurality of first mounting holes along the length direction of the connecting piece, the mounting frame is provided with a second mounting hole, and the bolt passes through the first mounting hole and the second mounting hole and is connected to the nut.

[0025] Optionally, the driving mechanism includes a driving motor, a support rod, a driving roller, a mounting tube and a driving spring; the driving roller is rotatably connected to the support rod, and the driving motor is arranged on the support rod and is transmission-connected to the driving roller; a limit block is provided on the outer side of the support rod, and the support rod is slidably sleeved in the mounting tube; the driving spring is sleeved on the outer side of the support rod, one end of the driving spring abuts against the limit block, and the other end of the driving spring abuts against the mounting tube; the mounting tube is fixed to the frame.

[0026] Optionally, the vibration mechanism includes a first rod, a second rod, a third rod, a rocker, a crank and a vibration motor;

[0027] One end of the first rod is rotatably connected to the frame, and the other end of the first rod is rotatably connected to the rocker; one end of the rocker away from the first rod is rotatably connected to the crank; the vibration motor is arranged on the frame and is used to drive the crank to rotate; one end of the second rod is rotatably connected to the middle part of the first rod, and the other end of the second rod is rotatably connected to the third rod;

[0028] The frame is provided with a mounting seat, and the mounting seat is provided with a sliding hole extending in a vertical direction; the third rod is matched with the sliding hole, and the third rod is fixedly connected to the bearing platform.

[0029] The technical solution of the present invention proposes a shock absorber friction test device, in which a driving mechanism drives the wheel to rotate on a bearing platform to simulate the state of the wheel during driving; at this time, the vibration mechanism drives the bearing platform to vibrate up and down to simulate the state of the wheel fluctuating up and down on an uneven road surface; the three-degree-of-freedom platform can drive the wheel to move along the X-axis, along the Y-axis, and rotate around the Z-axis to simulate the situation where the wheel rolls and slides on the road surface. Through the driving mechanism, the vibration mechanism and the three-degree-of-freedom platform, the state of the shock absorber in the actual working condition can be effectively simulated, and then the displacement sensor and the force sensor are used to record the excitation speed and damping force of the shock absorber respectively, so as to analyze the friction force of the shock absorber in the actual working condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 It is a structural schematic diagram of a vibration damper friction force test device according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the structure of a wheel and a driving mechanism according to an embodiment of the present invention;

[0033] Figure 3 Schematic diagram of the structure of the shock absorber according to the embodiment of the present invention.

[0034] Icons: 10, rack; 11, mounting seat; 20, three-degree-of-freedom platform; 210, mounting plate; 220, electric push rod; 230, workbench; 240, connecting piece; 2401, first mounting hole; 310, mounting frame; 320, shock absorber; 3210, first cylinder; 3220, second cylinder; 3230, shock-absorbing spring; 3240, screw; 32510, first bevel gear; 32520, second bevel gear; 32530, third bevel gear; 3260, generator; 3270, housing; 3280, transmission shaft; 3290, coupling axle; 330, swing arm assembly; 3310, upper swing arm; 3320, lower swing arm; 340, wheel; 350, displacement sensor; 360, force sensor; 410, drive motor; 420, support rod; 430, drive roller; 440, mounting tube; 450, drive spring; 510, bearing platform; 5110, first platform; 5120, second platform; 520, rotating roller; 610, first rod; 620, second rod; 630, third rod; 640, rocker; 650, crank; 660, vibration motor; 70, data collector. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0039] refer to Figure 1-Figure 3 A shock absorber friction force test device comprises: a frame 10; a three-degree-of-freedom platform 20, one end of which is arranged on the frame 10, and the other end is provided with a workbench 230; the three-degree-of-freedom platform 20 is used to drive the workbench 230 to move along the X-axis, along the Y-axis and rotate around the Z-axis; a suspension mechanism comprises a mounting frame 310, a shock absorber 320, a swing arm assembly 330 and a wheel 340; the mounting frame 310 is arranged on the workbench 230; one end of the swing arm assembly 330 is connected to the mounting frame 310, and the other end of the swing arm assembly 330 is rotatably connected to the wheel 340; one end of the shock absorber 320 is connected to the swing arm assembly 330, and the other end of the shock absorber 320 is connected to the mounting frame 310; a There are a displacement sensor 350 and a force sensor 360; the displacement sensor 350 is used to detect the excitation speed of the shock absorber 320; the force sensor 360 is used to detect the damping force exerted on the shock absorber 320; a driving mechanism is arranged on the frame 10 and is used to drive the wheel 340 to rotate; a bearing assembly includes a bearing platform 510 and a plurality of rotating rollers 520 rotatably connected to the bearing platform 510; wherein the wheel 340 abuts against the rotating rollers 520; a vibration mechanism, which is arranged on the frame 10 and is used to drive the bearing platform 510 to vibrate up and down; a processor, the three-degree-of-freedom platform 20, the driving mechanism, the displacement sensor 350, the force sensor 360 and the vibration mechanism are all electrically connected to the processor.

[0040] The driving mechanism drives the wheel 340 to rotate on the carrying platform 510 to simulate the state of the wheel 340 during driving; at this time, the vibration mechanism drives the carrying platform 510 to vibrate up and down to simulate the state of the wheel 340 fluctuating up and down on an uneven road surface; the three-degree-of-freedom platform 20 can drive the wheel 340 to move along the X-axis, move along the Y-axis, and rotate around the Z-axis to simulate the situation where the wheel 340 rolls and slides on the road surface. Through the driving mechanism, the vibration mechanism and the three-degree-of-freedom platform 20, the state of the shock absorber 320 in the real working condition can be effectively simulated, and then the displacement sensor 350 and the force sensor 360 are used to record the excitation speed and damping force of the shock absorber 320 respectively, so as to analyze the friction force of the shock absorber 320 in the real working condition.

[0041] The frame 10 may be a frame structure. When the frame 10 is placed on a horizontal ground, the vibration direction of the vibration mechanism is a vertical direction.

[0042] The upper end of the three-degree-of-freedom platform 20 can be fixed on the frame 10 , and the lower end of the three-degree-of-freedom platform 20 is connected to the mounting frame 310 .

[0043] The swing arm assembly 330 may include a lower swing arm 3320 and an upper swing arm 3310, and the wheel 340 includes a tire and a wheel hub. One end of the upper swing arm 3310 is rotatably connected to the wheel hub, and the other end of the upper swing arm 3310 is rotatably connected to the mounting frame 310; one end of the lower swing arm 3320 is rotatably connected to the wheel hub, and the other end of the lower swing arm 3320 is rotatably connected to the mounting frame 310. There are two upper swing arms 3310 and two lower swing arms 3320, and a connecting rod is provided between the two lower swing arms 3320. One end of the shock absorber 320 is rotatably connected to the connecting rod, and the other end of the shock absorber 320 passes through between the two upper swing arms 3310 and is rotatably connected to the mounting frame 310.

[0044] The displacement sensor 350 may be disposed on the shock absorber 320. The force sensor 360 may be disposed at the end of the shock absorber 320 connected to the mounting bracket 310.

[0045] The vibration damper friction force testing device may further include a data collector 70, which is used to record the data detected by the force sensor 360 and the displacement sensor 350. The data collector 70 may include a display and an operating platform both electrically connected to the processor.

[0046] The driving mechanism may be located on the side of the wheel 340 , and the driving mechanism contacts the outer side of the wheel 340 , and utilizes friction force to drive the wheel 340 to rotate relative to the swing arm assembly 330 .

[0047] The plurality of rotating rollers 520 are arranged along the radial direction of the wheel 340, and the axis of each rotating roller 520 is parallel to the axis of the wheel 340. When the wheel 340 remains stationary, the wheel 340 contacts one or more rotating rollers 520 in the middle. When the three-degree-of-freedom platform 20 drives the wheel 340 to simulate the side slip or side roll phenomenon, the plurality of rotating rollers 520 ensure that the wheel 340 can contact the rotating rollers 520, and the wheel 340 will not be separated from the rotating rollers 520.

[0048] The rotating roller 520 is detachably connected to the carrying platform 510; the rotating roller 520 includes a roller body and connecting shafts at both ends of the roller body; the carrying platform 510 includes a first platform 5110 and a second platform 5120, the first platform 5110 is connected to the vibration mechanism, the first platform 5110 is provided with a receiving groove for accommodating the roller body of the rotating roller 520 and a first clamping groove for clamping the connecting shaft, and the receiving groove is connected to the first clamping groove; the second platform 5120 is shaped like a cover plate, and the second platform 5120 is provided with a plurality of rolling holes for exposing the roller body and a second clamping groove corresponding to the first clamping groove, and the second clamping groove is also used for clamping the connecting shaft. The first platform 5110 can be provided with a threaded hole, and the second platform 5120 is covered on the first platform 5110, and a bolt is passed through the second platform 5120 and is threadedly connected to the first platform 5110, so that the first platform 5110 and the second platform 5120 can be connected.

[0049] The rotating roller 520 can be made of different materials. In some embodiments, the roller body can be formed by pouring concrete, and the connecting shaft is made of metal material. In this case, the rotating roller 520 and the wheel 340 are in contact, which can be used to simulate the situation where the wheel 340 is running on a concrete ground. In other embodiments, the connecting shaft can be made of metal material, and the side of the connecting shaft can be connected to a metal mesh, and the maximum outer diameter of the metal mesh is smaller than the outer diameter of the roller body. In this case, asphalt is poured on the outer side of the connecting shaft, and the asphalt is in close contact with the metal mesh. The poured asphalt forms the roller body, and the rotating roller 520 and the wheel 340 are in contact to simulate the situation where the wheel 340 is running on an asphalt ground.

[0050] As an optional implementation, based on the excitation speed of the shock absorber 320, the mechanical damping force of the shock absorber 320 is calculated using a friction algorithm, and the mechanical damping force is:

[0051] F p =f c sgn(v0)+c m v0;

[0052] Among them, F p represents the mechanical damping force, f c is the Coulomb friction force, c m represents the viscosity term of mechanical damping, sgn represents a sign function, and v0 represents the excitation velocity of the shock absorber 320 .

[0053] v0=2πfs0cos(2πft);

[0054] Wherein, f represents the excitation frequency, s0 represents the excitation amplitude, and t represents time. The excitation frequency and the excitation amplitude can be detected by the displacement sensor 350 , and then the excitation speed of the shock absorber 320 is further calculated.

[0055] In this embodiment, the shock absorber 320 is a feedback shock absorber. The mechanical damping force reflects the internal friction loss of the shock absorber, mainly including the friction inside the screw 3240, the bevel gear pair (including the first bevel gear 32510, the second bevel gear 32520 and the third bevel gear 32530) and the generator 3260, as well as the windage loss and magnetic loss of the generator 3260.

[0056] As an optional embodiment, the shock absorber 320 includes a first cylinder 3210, a second cylinder 3220, a shock absorbing spring 3230, a screw rod 3240, a transmission unit and a generator 3260;

[0057] One end of the first cylinder 3210 is connected to the mounting frame 310, and the other end of the first cylinder 3210 is slidably sleeved in the second cylinder 3220; a positioning block is provided on the outer side of the second cylinder 3220; one end of the second cylinder 3220 away from the first cylinder 3210 is connected to the swing arm assembly 330; the damping spring 3230 is sleeved on the outer side of the first cylinder 3210, one end of the damping spring 3230 abuts against the first cylinder 3210, and the other end of the damping spring 3230 abuts against the positioning block;

[0058] One end of the screw 3240 extends into the first cylinder 3210 and is threadedly connected to the first cylinder 3210, and the other end of the screw 3240 is transmission-connected to the transmission unit; the transmission unit is used to convert the forward and reverse rotation of the screw 3240 into the forward rotation of the shaft of the generator 3260, and the forward rotation state of the generator 3260 is the power generation state.

[0059] In this embodiment, when the vibration mechanism drives the wheel 340 to move upward, the second cylinder 3220 compresses the damping spring 3230 upward, and the second cylinder 3220 drives the screw 3240 to move upward. At this time, the first cylinder 3210 is relatively stationary. Since the screw 3240 is threadedly connected to the first cylinder 3210, the linear motion of the screw 3240 is converted into rotational motion, and the screw 3240 rotates forward at this time; when the vibration mechanism moves downward, the damping spring 3230 restores its original length to drive the second cylinder 3220 to move downward, and the screw 3240 rotates in the opposite direction. Regardless of whether the screw 3240 rotates forward or reversely, the transmission unit transmits the rotational motion of the screw 3240 to the generator 3260, so that the generator 3260 rotates to generate electricity.

[0060] The shock absorber friction force test device also includes a battery and a rectifier, the generator 3260, the rectifier and the battery are electrically connected in sequence, and the battery is electrically connected to the processor. Part of the energy lost by the shock absorber 320 can be converted into electrical energy by the generator 3260, and the electrical energy is finally stored in the battery. The electrical energy in the battery can be used for the displacement sensor 350 and the force sensor 360. In some embodiments, the automobile can adopt the shock absorber in this embodiment, and the electrical energy generated by the shock absorber 320 and the generator 3260 can be used for the electronic equipment of the automobile, such as some sensors.

[0061] The screw 3240 may be a ball screw, and a ball is provided in the matching structure between the screw 3240 and the first cylinder 3210 .

[0062] As an optional embodiment, the transmission unit includes a first bevel gear 32510, a second bevel gear 32520, a third bevel gear 32530, a first one-way bearing and a second one-way bearing;

[0063] A shell 3270 is provided at one end of the second cylinder 3220 away from the first cylinder 3210, and the transmission unit is located in the inner cavity of the shell 3270; the first bevel gear 32510 and the second bevel gear 32520 are both connected to the screw 3240 for transmission, a first one-way bearing is provided between the first bevel gear 32510 and the screw 3240, and a second one-way bearing is provided between the second bevel gear 32520 and the screw 3240; the first bevel gear 32510 and the second bevel gear 32520 are both meshed with the third bevel gear 32530, and the third bevel gear 32530 is fixed on the rotating shaft of the generator 3260.

[0064] In this embodiment, when the screw 3240 rotates forward, the first bevel gear 32510 rotates with the screw 3240, and the second bevel gear 32520 remains stationary; when the screw 3240 rotates reversely, the first bevel gear 32510 remains stationary, and the second bevel gear 32520 rotates with the screw 3240. Since the third bevel gear 32530 is meshed with the first bevel gear 32510 and the second bevel gear 32520 at the same time, when the first bevel gear 32510 drives the third bevel gear 32530 to rotate, the rotation direction of the third bevel gear 32530 is forward. At this time, the generator 3260 generates electricity, and the second bevel gear 32520 can also drive the third bevel gear 32530 to rotate forward.

[0065] In some embodiments, the third bevel gear 32530 can be fixed on the transmission shaft 3280, and the transmission shaft 3280 is connected to the rotating shaft of the generator 3260 through the coupling 3290.

[0066] As an optional embodiment, it also includes a side pressure telescopic rod; one end of the side pressure telescopic rod is set on the frame 10, and the other end of the side pressure telescopic rod abuts against the outer wall of the second cylinder 3220; the side pressure telescopic rod is electrically connected to the processor.

[0067] In this embodiment, the side pressure telescopic rod can be an electric push rod, and an arc-shaped rubber pad can be provided at one end of the side pressure telescopic rod abutting against the second cylinder 3220. The side pressure telescopic rod is used to apply a lateral force to the shock absorber 320, and the displacement sensor 350 and the force sensor 360 are used to detect the excitation speed and damping force of the shock absorber 320 to analyze the influence of the lateral force on the friction force of the shock absorber 320.

[0068] As an optional embodiment, the three-degree-of-freedom platform 20 includes a mounting plate 210 and three electric push rods 220; the mounting plate 210 is set on the frame 10; one end of each electric push rod 220 is rotatably connected to the mounting plate 210, and the other end of the electric push rod 220 is rotatably connected to the workbench 230; the electric push rod 220 is electrically connected to the processor.

[0069] In this embodiment, three electric push rods 220 are arranged on the mounting plate 210 at an interval of 120°. By controlling the three electric push rods 220 to extend to different lengths, the workbench 230 can be driven to move along the X-axis, along the Y-axis, and rotate around the Z-axis. For example, two of the electric push rods 220 extend by a, and the other electric push rod 220 extends by b. When a and b reach a certain amount, the workbench 230 can be moved horizontally. The specific values ​​of a and b can be measured experimentally.

[0070] As an optional embodiment, the workbench 230 is provided with a connecting member 240 extending along the vibration direction of the vibration mechanism, the connecting member 240 is provided with a plurality of first mounting holes 2401 along the length direction of the connecting member 240, the mounting frame 310 is provided with a second mounting hole, and the bolt passes through the first mounting hole 2401 and the second mounting hole and is connected to the nut.

[0071] In this embodiment, the second mounting hole is aligned with the first mounting hole 2401 at different positions, and the mounting frame 310 is fixed to the connecting member 240 by bolts and nuts, so that the distance between the center of the wheel 340 and the load-bearing platform 510 can be adjusted. When the shock absorbers of different vehicles are tested, the diameter of the wheel 340 may change, and the size of the swing arm assembly 330 may also change. At this time, the mounting frame 310 can be fixed at different positions of the connecting member 240 so that the wheel 340 contacts the load-bearing platform 510.

[0072] As an optional embodiment, the driving mechanism includes a driving motor 410, a support rod 420, a driving roller 430, a mounting tube 440 and a driving spring 450; the driving roller 430 is rotatably connected to the support rod 420, and the driving motor 410 is arranged on the support rod 420 and is transmission-connected to the driving roller 430; a limit block is provided on the outer side of the support rod 420, and the support rod 420 is slidably sleeved in the mounting tube 440; the driving spring 450 is sleeved on the outer side of the support rod 420, one end of the driving spring 450 abuts against the limit block, and the other end of the driving spring 450 abuts against the mounting tube 440; the mounting tube 440 is fixed on the frame 10.

[0073] In this embodiment, the driving motor 410 drives the driving roller 430 to rotate. The outer side of the driving roller 430 can be made of rubber material. The driving roller 430 drives the wheel 340 to rotate through friction. When the driving roller 430 contacts the surface of the wheel 340, there is a certain pressure between the driving roller 430 and the wheel 340. At this time, the driving roller 430 drives the support rod 420 to slide along the mounting cylinder 440, and the driving spring 450 is in a compressed state. When the vibration mechanism drives the wheel 340 to vibrate up and down, the contact point between the driving roller 430 and the wheel 340 changes. The existence of the driving spring 450 enables the support rod 420 to always drive the driving roller 430 to contact the surface of the wheel 340.

[0074] As an optional embodiment, the vibration mechanism includes a first rod 610, a second rod 620, a third rod 630, a rocker 640, a crank 650 and a vibration motor 660;

[0075] One end of the first rod 610 is rotatably connected to the frame 10, and the other end of the first rod 610 is rotatably connected to the rocker 640; one end of the rocker 640 away from the first rod 610 is rotatably connected to the crank 650; the vibration motor 660 is arranged on the frame 10 and is used to drive the crank 650 to rotate; one end of the second rod 620 is rotatably connected to the middle part of the first rod 610, and the other end of the second rod 620 is rotatably connected to the third rod 630;

[0076] The frame 10 is provided with a mounting seat 11 , and the mounting seat 11 is provided with a sliding hole extending in the vertical direction; the third rod 630 cooperates with the sliding hole, and the third rod 630 is fixedly connected to the bearing platform 510 .

[0077] In this embodiment, the first rod 610, the rocker 640 and the crank 650 form a crank 650 rocker 640 mechanism, the vibration motor 660 drives the crank 650 to rotate, the crank 650 then drives the first rod 610 to swing relative to the frame 10 through the rocker 640, the first rod 610 then drives the third rod 630 to move up and down through the second rod 620, and the sliding hole has a limiting effect on the third rod 630. The vibration frequency of the vibration mechanism is related to the rotation speed of the vibration motor 660, and the amplitude of the vibration mechanism is related to the length of the first rod 610, the crank 650 and the rocker 640.

[0078] In some embodiments, the first rod 610 may be an electric push rod. In this case, the first rod 610 is electrically connected to the processor, and the amplitude of the vibration mechanism can be changed by controlling the extension or contraction of the first rod 610, which is simple to operate.

[0079] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A vibration damper friction test device, characterized in that: include: frame; A three-degree-of-freedom platform, one end of which is arranged on the frame and the other end of which is provided with a workbench; The three-degree-of-freedom platform is used to drive the workbench to move along the X-axis, move along the Y-axis, and rotate around the Z-axis; The suspension mechanism comprises a mounting frame, a shock absorber, a swing arm assembly and a wheel; the mounting frame is arranged on the workbench; one end of the swing arm assembly is connected to the mounting frame, and the other end of the swing arm assembly is rotatably connected to the wheel; one end of the shock absorber is connected to the swing arm assembly, and the other end of the shock absorber is connected to the mounting frame; a displacement sensor and a force sensor are arranged on the shock absorber; the displacement sensor is used to detect the excitation speed of the shock absorber; and the force sensor is used to detect the damping force applied to the shock absorber; A driving mechanism, disposed on the frame and used to drive the wheel to rotate; The bearing assembly comprises a bearing platform and a plurality of rotating rollers rotatably connected to the bearing platform; wherein the wheels abut against the rotating rollers; A vibration mechanism, which is arranged on the frame and is used to drive the bearing platform to vibrate up and down; A processor, the three-degree-of-freedom platform, the driving mechanism, the displacement sensor, the force sensor and the vibration mechanism are all electrically connected to the processor.

2. The shock absorber friction force testing device according to claim 1, characterized in that: Based on the excitation speed of the shock absorber, the mechanical damping force of the shock absorber is calculated using a friction algorithm, and the mechanical damping force is: F p =f c sgn(v0)+c m v0; Among them, F p represents the mechanical damping force, f c is the Coulomb friction force, c m represents the viscous term of mechanical damping, sgn represents the sign function, and v0 represents the excitation velocity of the shock absorber.

3. The shock absorber friction force testing device according to claim 1, characterized in that: The shock absorber comprises a first cylinder, a second cylinder, a shock absorbing spring, a screw rod, a transmission unit and a generator; One end of the first cylinder is connected to the mounting frame, and the other end of the first cylinder is slidably sleeved in the second cylinder; a positioning block is provided on the outer side of the second cylinder; one end of the second cylinder away from the first cylinder is connected to the swing arm assembly; the damping spring is sleeved on the outer side of the first cylinder, one end of the damping spring abuts against the first cylinder, and the other end of the damping spring abuts against the positioning block; One end of the screw extends into the first cylinder and is threadedly connected to the first cylinder, and the other end of the screw is transmission-connected to the transmission unit; the transmission unit is used to convert both forward and reverse rotation of the screw into forward rotation of the shaft of the generator, and the forward rotation state of the generator is the power generation state.

4. The shock absorber friction force testing device according to claim 3, characterized in that: The transmission unit comprises a first bevel gear, a second bevel gear, a third bevel gear, a first one-way bearing and a second one-way bearing; A shell is provided at one end of the second cylinder away from the first cylinder, and the transmission unit is located in the inner cavity of the shell; the first bevel gear and the second bevel gear are both connected to the screw in driving manner, the first one-way bearing is provided between the first bevel gear and the screw, and the second one-way bearing is provided between the second bevel gear and the screw; the first bevel gear and the second bevel gear are both meshed with the third bevel gear, and the third bevel gear is fixed on the rotating shaft of the generator; when the screw rotates forward, the first bevel gear rotates with the screw, and the second bevel gear remains stationary; when the screw rotates reversely, the first bevel gear remains stationary, and the second bevel gear rotates with the screw.

5. The shock absorber friction force testing device according to claim 3, characterized in that: It also includes a side-pressure telescopic rod; one end of the side-pressure telescopic rod is arranged on the frame, and the other end of the side-pressure telescopic rod abuts against the outer side wall of the second cylinder; the side-pressure telescopic rod is electrically connected to the processor.

6. The shock absorber friction force testing device according to claim 3, characterized in that: It also includes a battery and a rectifier; the generator, the rectifier and the battery are electrically connected in sequence; and the battery is electrically connected to the processor.

7. The shock absorber friction force testing device according to claim 1, characterized in that: The three-degree-of-freedom platform includes a mounting plate and three electric push rods; the mounting plate is arranged on the frame; one end of each electric push rod is rotatably connected to the mounting plate, and the other end of the electric push rod is rotatably connected to the workbench; the electric push rod is electrically connected to the processor.

8. The shock absorber friction force testing device according to claim 1, characterized in that: The workbench is provided with a connecting piece extending along the vibration direction of the vibration mechanism, the connecting piece is provided with a plurality of first mounting holes along the length direction of the connecting piece, the mounting frame is provided with a second mounting hole, and the bolts pass through the first mounting hole and the second mounting hole and are connected with nuts.

9. The shock absorber friction force testing device according to claim 1, characterized in that: The driving mechanism includes a driving motor, a support rod, a driving roller, a mounting tube and a driving spring; the driving roller is rotatably connected to the support rod, the driving motor is arranged on the support rod and is transmission-connected to the driving roller; a limit block is provided on the outer side of the support rod, and the support rod is slidably sleeved in the mounting tube; the driving spring is sleeved on the outer side of the support rod, one end of the driving spring abuts against the limit block, and the other end of the driving spring abuts against the mounting tube; the mounting tube is fixed on the frame.

10. The shock absorber friction force testing device according to claim 1, characterized in that: The vibration mechanism comprises a first rod, a second rod, a third rod, a rocker, a crank and a vibration motor; One end of the first rod is rotatably connected to the frame, and the other end of the first rod is rotatably connected to the rocker; one end of the rocker away from the first rod is rotatably connected to the crank; the vibration motor is arranged on the frame and is used to drive the crank to rotate; one end of the second rod is rotatably connected to the middle part of the first rod, and the other end of the second rod is rotatably connected to the third rod; The frame is provided with a mounting seat, and the mounting seat is provided with a sliding hole extending in a vertical direction; the third rod is matched with the sliding hole, and the third rod is fixedly connected to the bearing platform.

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