Magnetorheological damper and magnetorheological damping device

Abstract

The application relates to the technical field of damping equipment, in particular to a magneto-rheological damper and a magneto-rheological damping device, which comprises an outer cylinder, an inner cylinder arranged in the outer cylinder, an upper end cover capped at the upper port of the outer cylinder, a lower end cover capped at the lower end buckle of the outer cylinder, a lifting support rod extending upwards and downwards and simultaneously penetrating through the upper end cover and the lower end cover, the inner cylinder is abutted between the upper end cover and the lower end cover, an outer warehouse capable of containing magneto-rheological liquid is formed among the outer cylinder, the inner cylinder, the upper end cover and the lower end cover, an inner warehouse capable of containing magneto-rheological liquid is formed among the inner cylinder, the lifting support rod, the upper end cover and the lower end cover, the outer warehouse and the inner warehouse are communicated on the upper side and communicated on the lower side, a coil is wound on the inner cylinder, a driving piston capable of being lifted in the inner warehouse to drive the flow of magneto-rheological liquid is arranged on the lifting support rod, and the magneto-rheological effect is better.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of damping devices, in particular to a magneto-rheological damper and a magneto-rheological damping device. BACKGROUND

[0002] The damper is widely used in various fields, and the magneto-rheological damper is also more used, especially in the suspension system of various vehicles, and is more used. The magneto-rheological fluid in the magneto-rheological damper is a new type of intelligent material, which can realize the rapid conversion between liquid and semi-solid state under the action of an external magnetic field, and the conversion process is reversible and controllable. The magneto-rheological fluid damper is designed according to the characteristics of the magneto-rheological fluid, has the advantages of fast response speed, good controllability, low power consumption and relatively simple structure, and is very suitable for application in the vehicle suspension system. At present, there are many types of magneto-rheological dampers.

[0003] A self-energy-collecting and self-sensing magneto-rheological damper is disclosed in Chinese patent No. 201210080180.X, which solves the problem that the existing magneto-rheological damper excessively relies on external sensors and control power supply, improves the reliability of the magneto-rheological damping device, and reduces the cost and maintenance cost. It includes an outer sleeve, a sealing element, a damper piston rod, a damper electromagnetic coil, a magneto-rheological fluid, a power generation unit and a motion mode conversion unit, the outer sleeve is provided with a sealing element, a damper piston rod, a damper electromagnetic coil, a magneto-rheological fluid, a power generation unit and a motion mode conversion unit.

[0004] A flexible semiconductor group temperature control constant temperature control system is disclosed in Chinese patent No. 201911234358.X, in particular a magneto-rheological damper capable of automatically controlling the constant temperature of magneto-rheological fluid. The magneto-rheological damper comprises a flexible semiconductor group distributed around the outer wall of the outer cylinder of the magneto-rheological damper, a temperature sensor inserted into the inner side of the damper on the left end cover of the damper, and an external controller. The flexible semiconductors are connected in series and connected to the external controller, and the temperature sensor is connected to the controller.

[0005] The flow range of the magneto-rheological fluid in the existing damper is not large enough, and the effectiveness of the coil acting on the magneto-rheological fluid and the area acted on are not optimized. SUMMARY

[0006] The purpose of the present application is to provide a magneto-rheological damper with better magneto-rheological effect.

[0007] The technical problem of the present application is solved by the following technical solution: a magneto-rheological damper, comprising an outer cylinder, an inner cylinder arranged in the outer cylinder, an upper end cover covering the upper end of the outer cylinder, a lower end cover covering the lower end of the outer cylinder, a lifting support rod extending upwards and downwards and passing through the upper end cover and the lower end cover, the inner cylinder being arranged between the upper end cover and the lower end cover, an outer chamber capable of containing magneto-rheological fluid being formed between the outer cylinder, the inner cylinder, the upper end cover and the lower end cover, an inner chamber capable of containing magneto-rheological fluid being formed between the inner cylinder, the lifting support rod, the upper end cover and the lower end cover, the outer chamber and the inner chamber being in communication at the upper side and in communication at the lower side, a coil being wound around the inner cylinder, and a driving piston being arranged on the lifting support rod and capable of being lifted in the inner chamber to drive the flow of magneto-rheological fluid.

[0008] As a preferred embodiment of the present application, the driving piston comprises a rigid piston body sleeve fixedly arranged on the lifting support rod, and a sealing rubber sleeve embedded on the outer wall of the rigid piston body sleeve and capable of abutting against the inner wall of the inner cylinder.

[0009] As a preferred embodiment of the present application, the coil comprises two or more groups of winding wires arranged at intervals.

[0010] As a preferred embodiment of the present application, the winding wires are wound around the outer side wall of the inner cylinder.

[0011] As a preferred embodiment of the present application, an annular winding groove is formed on the outer side wall of the inner cylinder for winding the winding wires.

[0012] As a preferred embodiment of the present application, the outer side wall of the inner cylinder comprises an upper flat guiding section, an intermediate buffering section and a lower flat guiding section connected in sequence from top to bottom, at least a part of the intermediate buffering section being radially protruded from the upper flat guiding section and the lower flat guiding section and forming a buffering protrusion.

[0013] As a preferred embodiment of the present application, the buffering protrusion has two or more annular protrusions arranged at intervals from top to bottom, and the part between adjacent two buffering protrusions forms the annular winding groove.

[0014] As a preferred embodiment of the present application, an upper side guiding hole is formed on the upper side of the inner cylinder for the upper side communication of the outer chamber and the inner chamber, and a lower side guiding hole is formed on the lower side of the inner cylinder for the lower side communication of the outer chamber and the inner chamber.

[0015] As a preferred embodiment of the present application, an assembly outer shaft sleeve is fixedly arranged on the outer side wall of the outer cylinder, and an annular stepped portion for spring support is formed on the assembly outer shaft sleeve.

[0016] The magnetorheological damping device comprises the magnetorheological damper, and a generator driven by the magnetorheological damper and capable of providing electric energy for the magnetorheological damper is connected to the lower end of the lifting support rod in the magnetorheological damper.

[0017] The magnetorheological damper in the application has a wider magnetorheological fluid flow range, higher uniformity of influence of a magnetic field, and better effectiveness, and is more suitable for a suspension system of a vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A schematic diagram of a three-dimensional structure of an inside of the magnetorheological damper in Example 1 after axial sectioning of one of the embodiments of the magnetorheological damper;

[0019] Figure 2 A schematic diagram of a three-dimensional structure of the generator driving part structure in Example 1 after removal of the coil and the sealing rubber sleeve; Figure 1

[0020] Figure 3 A schematic diagram of a three-dimensional structure of the magnetorheological damper in Example 1 after fixing and assembling of the outer shaft sleeve on the outside of the magnetorheological damper;

[0021] Figure 4 A schematic diagram of a three-dimensional structure of the magnetorheological damping device in Example 1;

[0022] Figure 5 A schematic diagram of a three-dimensional structure of the generator driving part structure in Example 1 after further optimization of the structure; Figure 4

[0023] Figure 6 A schematic diagram of a three-dimensional structure of the magnetorheological damping system in Example 2;

[0024] Figure 7 A schematic diagram of a three-dimensional structure of the base in Example 2 after sectioning. Figure 6 DETAILED DESCRIPTION

[0025] The following specific examples are only an explanation of the application, and are not a limitation of the application. Those skilled in the art can make modifications to the examples without creative contribution after reading the specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the application.

[0026] Example 1, as Figures 1-5 ​​​As shown, a magneto-rheological damper includes an outer cylinder 1, an inner cylinder 2 arranged in the outer cylinder 1, an upper end cover 3 covering the upper end of the outer cylinder 1, a lower end cover 4 covering the lower end of the outer cylinder 1, a lifting support rod 5 extending upward and downward and passing through the upper end cover 3 and the lower end cover 4, the cylinder, the end cover, and the lifting support rod 5 are made of conventional stainless steel metal materials, and the axial direction of the cylinder, the end cover, and the lifting support rod 5 is upward and downward, that is, in an upright state. After the lifting support rod 5 passes through the upper end cover 3 and the lower end cover 4, it moves up and down relative to the upper end cover 3 and the lower end cover 4 during work. In order to enable the lifting support rod 5 to be arranged in the central part of the upper end cover 3 and the lower end cover 4 and to move up and down smoothly, while ensuring sealing, a sealing ring is arranged on the upper end cover 3 and the lower end cover 4. The upper end cover 3 and the lower end cover 4 are flat and have a hole in the central part for the lifting support rod 5 to pass through. Therefore, a sealing ring m is arranged in the hole in the central part of the upper end cover 3 and the lower end cover 4 for the lifting support rod 5 to pass through. The outer cylinder 1, the upper end cover 3, and the lower end cover 4 are also preferably provided with a sealing ring m in the radial direction. A ring-shaped groove can be formed on the outer wall of the end cover for the sealing ring to be embedded. Further, the inner cylinder 2 abuts between the upper end cover 3 and the lower end cover 4, the outer cylinder 1, the inner cylinder 2, the upper end cover 3, and the lower end cover 4 form an outer warehouse a1 capable of containing magneto-rheological fluid, the inner cylinder 2, the lifting support rod 5, the upper end cover 3, and the lower end cover 4 form an inner warehouse a2 capable of containing magneto-rheological fluid, the outer warehouse a1 and the inner warehouse a2 are connected on the upper side and on the lower side, and the outer warehouse a1 and the inner warehouse a2 are two cylindrical spaces connected in communication, and the magneto-rheological fluid is contained in the outer warehouse a1 and the inner warehouse a2.

[0027] Further, the inner cylinder 2 is wound with a coil 20, and the lifting support rod 5 is sleeved with a driving piston 50 capable of lifting in the inner chamber a2 to drive the flow of the magnetorheological fluid. With this design, which is also a design point of the present application, the driving piston 50 is fixed to the lifting support rod 5 in the existing manner, and the driving piston 50 should also be a cylindrical structure as a whole, but in terms of size, the length of the driving piston 50 is smaller than that of the inner chamber a2, but the radial size of the driving piston 50 should be equal to or as consistent as possible with that of the inner chamber a2, so that the driving piston 50 is filled in the inner chamber a2 in the radial direction, and it can also be understood that the cross-sectional size and shape of the inner chamber are as consistent as possible with those of the driving piston 50. The purpose of this is that when the driving piston 50 moves up and down with the lifting support rod 5, the driving piston 50 can better push the magnetorheological fluid to flow to form a damping effect. For example, when the magnetorheological damper is used in the suspension system of a vehicle, the up-and-down movement of the lifting support rod 5 causes the driving piston 50 to move downward, and the lower surface of the driving piston 50 pushes the magnetorheological fluid below the driving piston 50 in the inner chamber a2 to move. The outer chamber a1 and the inner chamber a2 are in communication, so the magnetorheological fluid pushed downward in the inner chamber a2 flows into the outer chamber a1 from the lower side, and the magnetorheological fluid in the upper part of the outer chamber a1 flows into the inner chamber a2 from the upper communication position to fill the gap, thereby forming an internal circulation of the magnetorheological fluid flowing upward and downward, ensuring that the lifting support rod 5 is better buffered during the upward and downward movement, and making the suspension system better provide buffering for the vehicle.

[0028] As a preferred embodiment, the driving piston 50 includes a rigid piston body sleeve 51 fixed to the lifting support rod 5 and a sealing rubber sleeve 52 embedded on the outer wall of the rigid piston body sleeve 51 and capable of abutting against the inner wall of the inner cylinder 2. The rigid piston body sleeve 51 can be a steel cylindrical structure, and an annular embedding groove is formed in the middle of the outer wall of the rigid piston body sleeve 51 in the upward and downward direction. The purpose of the embedding groove is to enable the sealing rubber sleeve 52 to be embedded on the outer wall of the rigid piston body sleeve 51. The sealing rubber sleeve 52 can be a rubber or silicone sleeve. The purpose of this is to better move upward and downward and seal. The sealing here refers to the upward and downward sealing of the driving piston in the inner chamber. The radial size of the driving piston 50 can be slightly smaller than that of the inner chamber a2, and the difference therebetween is controlled to be within 1 mm. The sealing rubber sleeve 52 is also a cylindrical sleeve. When the sealing rubber sleeve 52 is embedded in the embedding groove, the outer wall of the sealing rubber sleeve 52 needs to slightly protrude from the rigid piston body sleeve 51 in the radial direction and tightly abut against the inner wall of the inner cylinder 2, so as to better fill the driving piston 50 in the inner chamber and smoothly move upward and downward and drive the magnetorheological fluid.

[0029] The above is the basic introduction of the magnetic fluid damper buffer function, followed by the application of the special design of the magnetic fluid in the damper, specifically:

[0030] The coil 20 includes two or more groups of winding 201 spaced apart, the winding 201 is wound on the outer wall of the inner cylinder 2. As introduced in the prior art, the coil of the existing magnetic fluid damper is powered to generate a magnetic field of corresponding size, and the magnetic fluid will exhibit different stiffness under the action of the magnetic field. The stronger the magnetic field, the stronger the stiffness of the magnetic fluid, so as to control the stiffness of the magnetic fluid damper. These coils can change the stiffness of the magnetic fluid by receiving electric energy provided by other components, so as to meet the demand of changing the buffer performance. Of course, the magnetic fluid damper can not receive electric energy, and it can work normally. At this time, the magnetic fluid is just the effect of ordinary oil damper fluid.

[0031] Further, the outer side wall of the inner cylinder 2 is formed with an annular winding groove 2011 for winding the winding 201. The thickness of the winding 201, that is, the radial dimension, is just filled into the annular winding groove 2011.

[0032] Further, the outer side wall of the inner cylinder 2 includes an upper flat guide section 21, an intermediate buffer section 22 and a lower flat guide section 23 connected in sequence, at least a part of the intermediate buffer section 22 is radially protruded from the upper flat guide section 21 and the lower flat guide section 23 and forms a buffer protrusion 2012. It needs to be ensured that there is a gap between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 for the up and down flow of the magnetic fluid, that is, the radial gap between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 is smaller than the radial gap between the upper flat guide section 21 and the inner wall of the cylinder 1, of course, the radial gap between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 is also smaller than the radial gap between the lower flat guide section 23 and the inner wall of the cylinder 1, that is, the intermediate buffer section 22 is more protruded in the radial direction, so as to cause the buffer of the path of the magnetic fluid in the up and down flow process itself, for example, when the vehicle is suddenly pressed to produce impact under severe vibration, the magnetic fluid will not flow rapidly and cannot be well buffered.

[0033] As preferred, the buffer protrusion 2012 has two or more and is spaced apart and annular protrusion, the part between the adjacent two buffer protrusions 2012 forms the annular winding groove 2011. The buffer protrusion 2012 can be provided with four, and the annular winding groove 2011 is three.

[0034] As preferred, the upper side of the inner cylinder 2 is provided with an upper side guide hole b1 for guiding the outer bin a1 and the inner bin a2 to pass through the upper side, and the lower side of the inner cylinder 2 is provided with a lower side guide hole b2 for guiding the outer bin a1 and the inner bin a2 to pass through the lower side. This is mainly for the flow of the magnetorheological fluid in the inner bin a2 and the outer bin a1, and is designed as much as possible at the upper and lower positions, and can be provided on the upper and lower flat guide sections to ensure that the flow area of the internal magnetorheological fluid is larger, and can also facilitate the range of magnetorheological fluid that can be affected by the magnetic field during the magnetorheological process.

[0035] In addition, in order to better install and use the magnetorheological damper, the outer cylinder 1 is fixed with an assembly outer shaft sleeve 11 on the outer side wall, which can be a steel shaft sleeve, and the assembly outer shaft sleeve 11 is provided with a spring support ring step portion.

[0036] The assembly outer shaft sleeve 11 is provided with a spring support ring step portion. The assembly outer shaft sleeve 11 can be provided with an upward ring step portion and a downward ring step portion on the upper and lower sides, respectively, so that the spring can be supported on the upper and lower sides, and the spring can be used in cooperation to form a better damping structure.

[0037] Next, a magnetorheological damping device is introduced, which includes the aforementioned magnetorheological damper, and the lower end of the lifting support rod 5 in the magnetorheological damper is connected with a generator 82 driven thereby and capable of providing electric energy for the lifting support rod 5, so as to form a self-powered magnetorheological damping system. The lifting support rod 5 moves linearly up and down as a power source for the generator to generate electricity, and the generator is connected to the coil winding in the damper through a wire to provide electric energy and form a variable magnetic field to change the stiffness of the magnetorheological fluid. Here, the lifting support rod 5 and the generator 82 can be connected by using an existing transmission connection structure that converts linear motion into circular motion, so that the linear motion of the lifting support rod 5 is converted into the circular motion of the generator rotor.

[0038] Next, two embodiments are introduced:

[0039] 1. The first structure is relatively simple, but more practical, that is, the rotor z of the generator 82 is directly connected and fixed with a ball screw nut 831 at the upper end, the ball screw nut 831 is axially in the up-down direction, the ball screw nut 831 is installed with a ball screw 832, the ball screw 832 is vertically in the up-down direction and a part is in the ball screw nut 831, so that the up-down movement of the ball screw 832 can drive the ball screw nut 831 to rotate, and further the upper end of the ball screw 832 is fixed with the lower end of the lifting support rod 5, so that the complete transmission power generation mode can be realized, and the up-down movement of the lifting support rod 5 can drive the ball screw 832 to move up and down, the up-down movement of the ball screw 832 can drive the ball screw nut 831 and the rotor z of the generator 82 to rotate, thereby generating electricity, the generator 82 is connected to the coil end of the damper through the corresponding wire, because the wire needs to be threaded, the sealing of the lead hole in the damper can be done, to prevent or reduce the leakage of the damping liquid, in this way, one generator and axial in the up-down direction can be used, the rotor axial direction is also in the up-down direction, the ball screw nut 831 is fixed at the upper part of the rotor z center, so that the lifting support rod 5, the ball screw 832, the ball screw nut 831 and the generator 82 are one-to-one corresponding in the up-down direction and the axial line is consistent, which is a simple and effective implementation way.

[0040] 2. The second method is a further optimization of the first method. The upper end of the ball screw 832 is still fixed to the lower end of the lifting support rod 5, and the lower part of the ball screw 832 is also installed in the ball screw nut 831. The difference is that the ball screw nut 831 and the rotor z are also connected, but not directly. Instead, a horizontal central gear c1 is fixed to the lower end of the ball screw nut 831. Two or more generators 82, preferably three, are arranged in a circular array around the central gear c1. A drive gear c2 is fixed to the upper end of the rotor z of each generator 82. Each drive gear c2 meshes with the central gear c1 and is horizontal, simultaneously driving... The driving gears c2 are arranged in a circular array on the central gear c1. When the ball screw nut 831 is driven to rotate, the central gear c1 acts as the center in the gear transmission, causing each driving gear c2 to rotate as well. This rotation of each rotor generates electricity for its corresponding generator. This allows the damper to have three sets of different coils forming their own windings. For example, the three coils form three independent windings, and each of the three generators is connected to one of these windings via different wires, forming three independent power generation connections. This allows the three windings in the damper to generate electricity simultaneously, resulting in better synchronization, stability, and reduced feedback lag time. In the first embodiment, there are also three windings, but because it's a single generator structure, these three windings are wound with the same coil wire. This causes a certain lag in power transmission. More importantly, if one generator fails, it cannot be implemented in scenarios requiring magnetorheological operation. Three generators effectively avoid this problem; even if one generator fails, the system can still function, making it safer and more reliable.

[0041] Of course, in the design of this self-powered magnetorheological damping device, an automated system controls the conductor's path, switching the conductor's on / off state to achieve self-powered operation. This is because sometimes the magnetorheological effect is not needed; the device is activated when required, and when not, even if the lifting support rod 5 moves up and down to generate electricity, no magnetorheological activity will occur. This more practical operational requirement can be controlled. Overall, the damping structure design of this application is safer and more stable, the magnetorheological effect is more stable and reliable, and it can supply its own power without requiring external power input, making it very convenient and effective.

[0042] The magnetorheological damper and magnetorheological damping device of this embodiment can be applied to the magnetorheological damping system in Embodiment 2, making the use of the magnetorheological damping system in vehicles safer and more reliable, and enhancing the vehicle's operational stability and service life.

[0043] More specifically, the magneto-rheological damping device can include the magneto-rheological damper, the upper and lower buffer springs 71 and 72 arranged above and below the magneto-rheological damper, the self-powered support device driven by the magneto-rheological damper and capable of powering the magneto-rheological damper and supporting the magneto-rheological damper in the up-and-down direction, and the lifting support rod 5 for driving the self-powered support device to be powered. Details of the implementation will be further described in Embodiment 2.

[0044] Embodiment 2, as shown in the figure, a magneto-rheological damping system, the magneto-rheological damping system of the present embodiment is mentioned above, can use the damper and damping device in embodiment 1, but not limited to the damper and damping device in embodiment 1. Figures 6-7

[0045] Specifically, the system includes a magneto-rheological damping device and a suspension control module for controlling the magneto-rheological damping device, the magneto-rheological damping device includes a magneto-rheological damper, upper and lower buffer springs 71 and 72 arranged above and below the magneto-rheological damper, a self-powered support device driven by the magneto-rheological damper and capable of powering the magneto-rheological damper and supporting the magneto-rheological damper in the up-and-down direction, the magneto-rheological damper has a lifting support rod 5 for driving the self-powered support device to be powered, the upper end of the lifting support rod 5 is fixed with an outer end cover 73, the self-powered support device has a base 81 and a generator 82 stored in the base 81 and capable of being driven by the lifting support rod 5 to be powered, the upper buffer spring 71 is sleeved on the periphery of the magneto-rheological damper and supported between the outer end cover 73 and the magneto-rheological damper, and the lower buffer spring 72 is sleeved on the periphery of the magneto-rheological damper and supported between the magneto-rheological damper and the base 81. The outer end cover 73 is connected with the structure of the vehicle chassis and will float up and down, through the combination of the two springs and dampers, a more controllable damping structure is formed, in the process of vehicle vibration, the direct action of the spring and the more accurate damping control of the damper can realize more safe and reliable damping effect of the vehicle, and the self-powered structure can form better magneto-rheological operation. The base 81 can adopt a conventional steel case or rack structure, and the generator 82 can be installed and fixed in the base 81. In order to sleeve the spring, the lower part of the outer end cover 73 should be provided with a downward annular step structure for sleeving the upper end of the upper buffer spring 71, the upper part of the base 81 should be provided with an upward annular step structure for sleeving the lower end of the lower buffer spring 72, and the outer peripheral part of the middle of the magneto-rheological damper should be provided with corresponding step parts for sleeving and abutting of the upper and lower buffer springs.

[0046] ​Further, the rotor of the generator 82 is connected with a ball screw nut 831, the ball screw nut 831 is installed with a ball screw 832, the upper end of the ball screw 832 is fixed with the lower end of the lifting support rod 5, here can refer to the two implementation modes of embodiment 1 for connection.

[0047] Similarly, as preferred, the magnetic rheological damper is fixed with an assembled outer shaft sleeve 11. And, the upper buffer spring 71 is between the outer end cover 73 and the assembled outer shaft sleeve 11, the lower buffer spring 72 is between the assembled outer shaft sleeve 11 and the base 81, so the upper and lower sides of the assembled outer shaft sleeve 11 need to be respectively formed with an upward annular step part and a downward annular step part, so as to facilitate the lower end of the upper buffer spring 71 to be downwardly sleeved and abut on the upper side of the assembled outer shaft sleeve 11 and the upper end of the lower buffer spring 72 to be upwardly sleeved and abut on the lower side of the assembled outer shaft sleeve 11.

[0048] Further, in the design of the system in the control aspect: the suspension control module includes a laser sensor, a MOSFET switch and a suspension controller, all of which can adopt existing electronic equipment. The MOSFET switch can be arranged on the circuit in which the lead wire of the generator is in communication with the coil in the damper.

[0049] Further, it also includes a road excitation generation system, which includes a hydraulic cylinder, a hydraulic valve, a hydraulic station, a laser sensor and an excitation controller controlled by a PID algorithm, all of which can adopt existing road excitation generation system modules.

[0050] The application of the magnetic rheological damping system of the present application in the control aspect in the implementation is as follows:

[0051] Firstly, in order to realize the damping effect of the vehicle under different road conditions, the present application provides a system of a compact stiffness controllable magnetic rheological damper which can control self-power supply, so as to ensure that the effect of rapid damping can be realized without providing external power supply and the best stiffness control effect can be achieved.

[0052] To realize the control of the self-powered compact stiffness controllable MR damper system, a quarter car test system, which has been widely used to evaluate the ride comfort of vehicle suspension, can be used. The test system consists of a vehicle body, a suspension system, a controller and a road excitation generation system, which includes a hydraulic cylinder, a hydraulic valve, a hydraulic station, a laser sensor and an implementation excitation controller controlled by a PID algorithm. The suspension control system consists of two laser sensors, a MOSFET switch and an implementation suspension controller. The laser sensors are used to collect the displacement of the sprung mass and the stroke of the MR damper, the MOSFET switch is controlled by the suspension controller and is used to control the working mode of the self-powered circuit, and the MOSFET switch is arranged in the circuit in which the generator and the damper coil are connected. The control system outside the MOSFET switch can be generally installed in the vehicle body and can be arranged together with other control modules of the vehicle.

[0053] Then the circuit has two working modes. When the input PWM signal is +10V from the suspension controller, the MOSFET switch is opened, thereby turning on the circuit between the coil in the MR damper and the generator for self-power supply. In this case, the MR damper is excited by the self-powered energy, resulting in an increase in the damping force and the stiffness of the device. When the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be closed, and the circuit will be closed. In this case, the self-powered energy will not be used to power the MR damper, and there will be no stiffness change effect of the MR damper. That is, when the input PWM signal is +10V from the suspension controller, the MOSFET switch is opened, the circuit between the coil in the MR damper and the generator wire is turned on, the MR damper is excited by the self-powered support device, resulting in an increase in the damping force and the stiffness of the MR damper. When the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be closed, the circuit between the coil in the MR damper and the generator wire will be closed, and the self-powered support device will not be used to power the MR damper.

[0054] The quarter car test bench is excited by harmonic excitation with a scanning frequency to obtain the transmissibility of the vehicle suspension by using a frequency of 0.5-2.75 Hz, and four kinds of suspensions are tested: three passive suspensions powered by constant external currents of 0A, 1.2A and 2A, and a self-powered suspension using self-power generation. It is obtained by comparing frequency analysis that if the excitation frequency is in the range of 0.5-2.1 Hz, the transmissibility of the self-powered suspension is much lower than that of the passive 0A suspension; if the excitation frequency is in the range of 2.1-2.75 Hz, the passive 0A is lower than the automatic power supply and the passive 1.2A and 2A transmissibility. Passive means external power supply, not self-power supply. From the above experiment, it can be seen that at low frequency, such as less than 2.1 Hz as mentioned above, the current is not needed for magneto-rheological change in stiffness, which is more effective, so self-power supply or external current input is not needed, at this time, any power supply condition is not needed, and when the frequency is more than 2.1 Hz, the current input to the damper is better, so it is appropriate to open the circuit for magneto-rheological, in the system of the application, that is, under high frequency vibration, the switch needs to be opened for self-power supply.

[0055] Therefore, it is concluded that if the excitation frequency is less than 2.1 Hz, the passive input 0V and the current 0A are used; if the excitation frequency is greater than 2.1 Hz, the self-power supply mode is used. Therefore, the system of the embodiment can change the power supply mode of the stiffness controllable magneto-rheological damper according to the bumping degree of the road, when the bumping frequency is less than 2.1 Hz, the suspension controller will close the MOSFET tube, and the self-power supply function of the stiffness controllable magneto-rheological damper will be closed; when the bumping frequency is greater than 2.1 Hz, the suspension controller will open the MOSFET tube, and the self-power supply function of the stiffness controllable magneto-rheological damper will be opened. Therefore, the control system of the application contains a suspension controller and a MOSFET tube, so that the stiffness controllable magneto-rheological damper can have a better vibration reduction mode on the road vibration of different frequencies. Moreover, the STFT control strategy used in the control system realizes the comparison of the vibration transmissibility of the self-power supply and the passive power supply under different frequencies, so as to find the frequency threshold.

[0056] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto, and any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the application, which should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A magnetorheological damper, characterized by, The application relates to a magnetorheological damper, which comprises an outer cylinder (1), an inner cylinder (2) arranged in the outer cylinder (1), an upper end cover (3) covering the upper end of the outer cylinder (1), a lower end cover (4) covering the lower end of the outer cylinder (1), a lifting support rod (5) extending upwards and downwards and penetrating through the upper end cover (3) and the lower end cover (4), the inner cylinder (2) is arranged between the upper end cover (3) and the lower end cover (4), an outer chamber (a1) capable of containing magnetorheological liquid is formed between the outer cylinder (1), the inner cylinder (2), the upper end cover (3) and the lower end cover (4), an inner chamber (a2) capable of containing magnetorheological liquid is formed between the inner cylinder (2), the lifting support rod (5), the upper end cover (3) and the lower end cover (4), the outer chamber (a1) and the inner chamber (a2) are communicated at the upper side and the lower side, a coil (20) is arranged on the inner cylinder (2), and a driving piston (50) capable of lifting in the inner chamber (a2) to drive the flow of the magnetorheological liquid is arranged on the lifting support rod (5).

2. The magnetorheological damper of claim 1, wherein, The driving piston (50) comprises a rigid piston body sleeve (51) fixedly arranged on the lifting support rod (5) and a sealing rubber sleeve (52) embedded on the outer wall of the rigid piston body sleeve (51) and capable of abutting against the inner wall of the inner cylinder (2).

3. The magnetorheological damper of claim 1, wherein, The coil (20) comprises two or more groups of winding wires (201) arranged at intervals.

4. A magnetorheological damper according to claim 3, wherein The winding wires (201) are wound on the outer wall of the inner cylinder (2).

5. The magnetorheological damper of claim 3, wherein, An annular winding groove (2011) is formed on the outer wall of the inner cylinder (2) for winding the winding wires (201).

6. A magnetorheological damper according to claim 5, wherein, The outer wall of the inner cylinder (2) comprises an upper flat guiding section (21), an intermediate buffering section (22) and a lower flat guiding section (23) connected in sequence from top to bottom, at least a part of the intermediate buffering section (22) is protruded in the radial direction from the upper flat guiding section (21) and the lower flat guiding section (23) and forms a buffering protrusion (2012).

7. A magnetorheological damper according to claim 6, wherein The buffering protrusion (2012) has two or more annular protrusions arranged at intervals from top to bottom, and the part between two adjacent buffering protrusions (2012) forms the annular winding groove (2011).

8. The magnetorheological damper of claim 1, wherein, An upper guiding hole (b1) is formed on the upper side of the inner cylinder (2) for the upper side communication of the outer chamber (a1) and the inner chamber (a2), and a lower guiding hole (b2) is formed on the lower side of the inner cylinder (2) for the lower side communication of the outer chamber (a1) and the inner chamber (a2).

9. The magnetorheological damper of claim 1, wherein, An assembly outer shaft sleeve (11) is fixed on the outer wall of the outer cylinder (1), and an annular stepped portion for spring supporting is formed on the assembly outer shaft sleeve (11).

10. A magnetorheological damping device, characterized by The magnetorheological damper comprises any one of the magnetorheological dampers in claims 1-9, and a generator (82) is connected to the lower end of the lifting support rod (5) and driven by the lifting support rod (5) to provide electric energy for the lifting support rod (5).

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