Piston assembly and magnetorheological damper

Abstract

The utility model provides a piston assembly and a magneto-rheological shock absorber. The piston assembly comprises a piston shell, a magnetic force driving assembly and a base, wherein a first damping hole and a second damping hole are formed in the two ends of the piston shell respectively. The magnetic driving assembly is electrically connected with an electric connecting piece in the piston rod, and a damping channel communicated with the first damping hole is formed between the magnetic driving assembly and the piston shell; a first channel and a second channel are formed in the base, the circulation section of the second channel is smaller than that of the first channel and that of the damping channel, and the sliding block in the base can slide between a first position and a second position under the driving of the magnetic driving assembly; when the sliding block is at the first position, the damping channel is communicated with the second damping hole through the first channel, and when the sliding block is at the second position, the damping channel is communicated with the second damping hole through the second channel. When the piston assembly is applied to the shock absorber, damping force can be adjusted when the piston assembly is powered on, and necessary damping force can be provided when power failure or power supply failure occurs.

Description

Technical Field

[0001] The utility model relates to the technical field of shock absorbers, and in particular to a piston assembly. The utility model also relates to a magnetorheological shock absorber provided with the piston assembly. Background Art

[0002] Magnetorheological shock absorbers have the characteristics of controllable damping, fast response, and wide adjustable range. The basic principle is to change the magnetic field intensity in the damping channel by changing the current in the coil, thereby changing the shear yield strength of the magnetorheological fluid, and finally achieving the purpose of changing the output damping force of the shock absorber.

[0003] Magnetorheological shock absorbers have a considerable application market in some performance-oriented cars. Based on the characteristics of the magnetic field and fluid in the magnetorheological shock absorber structure, as the current increases, the damping provided by the magnetorheological shock absorber will also increase. When there is no current, the damping of the magnetorheological shock absorber is the lowest.

[0004] Since the damping of the magnetorheological shock absorber is the softest and cannot be adjusted when there is no power or power failure, the existing magnetorheological shock absorber cannot provide sufficient damping for the suspension system using the magnetorheological shock absorber, which can easily lead to unsafe situations such as severe vehicle roll when turning and increased braking distance during emergency braking, and cannot well ensure the safety of the driver and the vehicle. Therefore, it is urgent to improve the structure of the magnetorheological shock absorber. Utility Model Content

[0005] In view of this, the utility model aims to provide a piston assembly, which, when applied to a shock absorber, can enable the shock absorber to provide necessary damping force when a power outage or power failure occurs.

[0006] In order to achieve the above object, the technical solution of the utility model is implemented as follows:

[0007] A piston assembly comprises a piston housing with a first damping hole and a second damping hole respectively disposed at two ends, and a magnetic drive component and a base disposed in the piston housing;

[0008] The magnetic drive assembly is fixed on the piston rod and electrically connected to the electrical connector in the piston rod. A damping channel is formed between the magnetic drive assembly and the piston housing, and one end of the damping channel is connected to the first damping hole.

[0009] The base is provided with a first channel and a second channel, the flow cross section of the second channel is smaller than the flow cross sections of the first channel and the damping channel, and the base is provided with a slider, the slider is driven by the magnetic drive assembly and can slide between a first position and a second position in the base;

[0010] When the slider is in the first position, the other end of the damping channel is connected to the second damping hole through the first channel. When the slider is in the second position, the other end of the damping channel is connected to the second damping hole through the second channel.

[0011] Furthermore, the slider is slidably disposed in the mounting cavity in the base, and a connecting hole is provided in the slider for connecting the second channel with the second damping hole; the flow cross section of the connecting hole is larger than the flow cross section of the second damping hole.

[0012] Furthermore, a connecting channel communicating with the damping channel is provided in the base; the first channel and the second channel are connected in parallel between the connecting channel and the installation cavity.

[0013] Furthermore, an elastic reset member is provided between the slider and the base; the elastic reset member can store energy when the slider slides from the second position to the first position, and when the elastic reset member releases energy, it can drive the slider to slide from the first position to the second position.

[0014] Furthermore, the magnetic drive assembly includes an iron core fixed on the piston rod, and an electromagnetic coil sleeved on the iron core; the electrical connector in the piston rod passes through the iron core and is electrically connected to the electromagnetic coil.

[0015] Furthermore, the piston housing includes a piston cylinder, and a first end cover and a second end cover arranged at both ends of the piston cylinder; the first damping hole is arranged on the first end cover, and the second damping hole is arranged on the second end cover, and the magnetic drive assembly, the base, the first end cover and the second end cover are located in the piston cylinder.

[0016] Furthermore, a first seal is provided on the base for sealing between the base and the piston cylinder; and / or a second seal is provided between the slider and the base, and the second seal is used to seal the gap between the first channel and the second channel.

[0017] Compared with the prior art, the utility model has the following advantages:

[0018] The piston assembly described in the utility model, through the piston housing and the magnetic drive component and base arranged in the piston housing, enables the slider in the base to slide between the first position and the second position under the drive of the magnetic drive component, and when the slider is in the first position and the second position, different damping passages are formed between the first damping hole and the second damping hole, so that when the magnetic drive component is energized, the damping fluid passes through the first channel with a larger flow cross-section, and the viscosity of the damping fluid is controlled by adjusting the energizing current to achieve damping force adjustment; when the magnetic drive component is powered off or a power failure occurs, the damping fluid passes through the second channel with a smaller flow cross-section, so that when the power is off or the power fails, the shock absorber can provide the necessary damping force and has a good use effect.

[0019] In addition, the setting of the installation cavity can provide space for the installation and sliding of the slider, and the connecting hole set in the slider can connect the second channel with the second damping hole, so that when the slider is in the second position, a connecting channel is formed between the second damping hole and the damping channel; and the flow cross-section of the connecting hole is set to be larger than the flow cross-section of the second damping hole, which can form a smaller pressure in the connecting hole, thereby preventing the damping fluid on the side of the piston assembly close to the base from pushing the slider out of the second position, thereby ensuring that the second channel is connected to the second damping hole and the damping channel respectively.

[0020] Secondly, the setting of the connecting channel and the parallel arrangement of the first channel and the second channel are conducive to the processing and preparation of the first channel, the second channel and the connecting channel, and make the structure of the base relatively simple. The setting of the elastic reset member can utilize the energy release of the elastic reset member when the magnetic drive component is powered off, so that the slider can move smoothly from the first position to the second position, and it can also save the reverse current passed into the magnetic drive component, which is low in cost. The magnetic drive component adopts an iron core and an electromagnetic coil, which has a simple structure and mature technology.

[0021] In addition, the piston housing includes a piston cylinder and a first end cover and a second end cover, which not only facilitates the arrangement of the magnetic drive assembly and the base, but also makes the overall structure of the piston assembly more compact. The first seal is provided to better seal the base and the piston cylinder. The second seal is provided to seal the gap between the first channel and the second channel, thereby ensuring better isolation between the first channel and the second channel when the slider is in the first position and the second position respectively.

[0022] Another object of the utility model is to provide a magnetorheological damper, in which a floating piston is slidably provided in the cylinder of the magnetorheological damper, and the piston assembly as described above; the floating piston separates the cavity in the cylinder into an air cavity and a liquid cavity, the air cavity is provided with gas, the liquid cavity is provided with magnetorheological fluid, and the piston assembly is arranged in the liquid cavity.

[0023] Furthermore, a third seal is provided between the floating piston and the cylinder, and the third seal is used to seal the gap between the floating piston and the cylinder; and / or a lubricating member is provided between the floating piston and the cylinder, and the lubricating member is made of self-lubricating material.

[0024] Furthermore, an oil seal guide assembly is provided at one end of the cylinder away from the air cavity, and the oil seal guide assembly has a sealing component for sealing between the piston rod and the cylinder, and a guide member for guiding the movement of the piston rod.

[0025] Compared with the prior art, the utility model has the following advantages:

[0026] The magnetorheological shock absorber of the utility model adopts the above-mentioned piston assembly, so that when the magnetorheological shock absorber is powered on, the magnitude of the input current is used to achieve rapid adjustment of the damping, and when the power is off or the power supply is abnormal, the magnetorheological shock absorber can still provide a certain damping force. Especially when it is used in the suspension system of a vehicle, the side tilt of the vehicle when turning due to insufficient damping can be avoided, thereby ensuring the safety of the driver and the vehicle, and having a good use effect.

[0027] In addition, the third seal provided between the floating piston and the cylinder barrel can ensure the sealing effect between the air cavity and the liquid cavity. The lubricating member provided between the floating piston and the cylinder barrel, and the lubricating member made of self-lubricating material, can reduce the friction resistance when the floating piston moves, so as to timely compensate for the volume of the air cavity or the liquid cavity during use. The setting of the oil seal guide assembly can ensure the sealing effect between the piston rod and the cylinder barrel, and also facilitate the guided movement of the piston rod in the cylinder barrel. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the accompanying drawings:

[0029] Figure 1 It is a structural schematic diagram of the magnetorheological damper according to an embodiment of the utility model;

[0030] Figure 2 This is a schematic structural diagram of the piston assembly in the embodiment of the utility model in the energized state;

[0031] Figure 3 This is a schematic structural diagram of the piston assembly in a power-off state according to an embodiment of the utility model;

[0032] Figure 4 for Figure 1 Enlarged view of part A in the middle;

[0033] Figure 5 for Figure 1 Enlarged view of middle part B;

[0034] Description of reference numerals:

[0035] 1. Cylinder barrel; 2. Piston rod; 3. Piston assembly; 4. Floating piston; 5. Oil seal guide assembly;

[0036] 21. electrical connector; 31. piston housing; 32. magnetic drive assembly; 33. base; 34. slider; 35. elastic reset member; 210. block; 311. piston cylinder; 312. first end cover; 3120. first damping hole; 313. second end cover; 3130. second damping hole; 321. iron core; 322. electromagnetic coil; 330. mounting cavity; 331. first sealing member; 341. second sealing member; 401. third sealing member; 402. lubricating member; 51. guide; 52. guide member; 53. oil seal; 54. cover plate; 55. retaining spring; 56. fourth sealing member;

[0037] 10. Damping channel; 20. First channel; 30. Second channel; 40. Connecting channel; 50. Connecting hole; 100. Air cavity; 200. Liquid cavity. DETAILED DESCRIPTION

[0038] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0039] In the description of the present invention, it should be noted that if there are terms such as "upper", "lower", "inner", "outer" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if there are terms such as "first" and "second", they are also used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In addition, in the description of the present invention, unless otherwise clearly defined, the terms "installation", "connection", "connection" and "connector" should be understood in a broad sense. For example, it 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 it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in combination with specific circumstances.

[0041] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0042] Embodiment 1

[0043] The present embodiment relates to a piston assembly, which enables the shock absorber to provide necessary damping force when power is off or fails.

[0044] In terms of overall composition, see Figure 2 and Figure 3 , and combined with Figure 1 As shown, the piston assembly 3 of this embodiment includes a piston housing 31 with a first damping hole 3120 and a second damping hole 3130 respectively provided at two ends, and a magnetic drive component 32 and a base 33 provided in the piston housing 31.

[0045] The magnetic drive assembly 32 is fixed on the piston rod 2 and electrically connected to the electrical connector 21 in the piston rod 2. A damping channel 10 is formed between the magnetic drive assembly 32 and the piston housing 31. One end of the damping channel 10 is connected to the first damping hole 3120. In addition, the base 33 is provided with a first channel 20 and a second channel 30. The flow section of the second channel 30 is smaller than the flow sections of the first channel 20 and the damping channel 10. A slider 34 is provided in the base 33. The slider 34 is driven by the magnetic drive assembly 32 and can slide between a first position and a second position in the base 33. When the slider 34 is in the first position, the other end of the damping channel 10 is connected to the second damping hole 3130 through the first channel 20. When the slider 34 is in the second position, the other end of the damping channel 10 is connected to the second damping hole 3130 through the second channel 30.

[0046] In the above structure, the first channel 20 and the second channel 30 are arranged in the base 33, so that when the slider 34 is in the first position, one end of the damping channel 10 is connected with the first damping hole 3120, and the other end of the damping channel 10 is connected with the second damping hole 3130 through the first channel 20; when the slider 34 is in the second position, one end of the damping channel 10 is connected with the first damping hole 3120, and the other end of the damping channel 10 is connected with the second damping hole 3130 through the second channel 30.

[0047] Thus, when the slider 34 is in the first position and the second position, different damping paths are formed between the first damping hole 3120 and the second damping hole 3130. Furthermore, when the magnetic drive assembly 32 is powered on, the damping fluid passes through the first channel 20 with a larger flow section, and the damping force is adjusted by adjusting the magnitude of the power-on current to control the viscosity of the damping fluid. When the magnetic drive assembly 32 is powered off or a power failure occurs, the damping fluid passes through the second channel 30 with a smaller flow section, so that the shock absorber can also provide the necessary damping force.

[0048] It should be noted that the magnetic drive component 32 drives the slider 34 to slide between the first position and the second position in the base 33. In specific implementation, for example, a forward current and a reverse current can be passed into the magnetic drive component 32 to generate magnetic forces in opposite directions. At this time, the slider 34 moves between the first position and the second position under the action of magnetic forces in opposite directions. It is also possible to pass a current in only one direction into the magnetic drive component 32 to generate a magnetic force in one direction. The magnetic force cooperates with the gravity of the slider 34 itself to achieve the movement of the slider 34 between the first position and the second position when the magnetic drive component 32 is powered on or off.

[0049] Of course, an elastic reset member 35 can also be provided. When the magnetic drive assembly 32 is powered, the slider 34 moves, and the elastic reset member 35 stores energy. When the magnetic drive assembly 32 is powered off, the elastic reset member 35 releases energy and drives the slider 34 to move in the opposite direction, thereby realizing the movement of the slider 34 between the first position and the second position. This is also possible.

[0050] In addition, it should be noted that the first position in this embodiment, that is, the position of the slider 34 when the magnetic drive assembly 32 is powered on, is also Figure 2 , at this time, the damping passage is as shown by the arrow, the first damping hole 3120, the damping channel 10, the connecting channel 40, the first channel 20 and the second damping hole 3130 are connected, and when there is a pressure difference in the liquid chambers on both sides of the piston assembly, the damping fluid can flow in the direction of the arrow or the opposite direction of the arrow. The second position in this embodiment, which is also the position of the slider 34 when the magnetic drive assembly 32 is powered off, is also shown in FIG. Figure 3 , at this time, the damping passage is as shown by the arrow, the first damping hole 3120, the damping channel 10, the connecting channel 40, the second channel 30 and the second damping hole 3130 are connected, and when there is a pressure difference in the liquid chambers on both sides of the piston assembly, the damping fluid can flow in the direction of the arrow or the opposite direction of the arrow.

[0051] For more details, see Figure 2 and Figure 3 As shown, as a preferred embodiment, in this embodiment, the piston housing 31 includes a piston cylinder 311, and a first end cover 312 and a second end cover 313 provided at both ends of the piston cylinder 311. Among them, the first damping hole 3120 is provided on the first end cover 312, the second damping hole 3130 is provided on the second end cover 313, and the magnetic drive assembly 32, the base 33, the first end cover 312 and the second end cover 313 are limited in the piston cylinder 311. Such a design is not only conducive to the arrangement and installation of the magnetic drive assembly 32 and the base 33, but also makes the overall structure of the piston assembly 3 more compact.

[0052] In this embodiment, the slider 34 is slidably disposed in the mounting cavity 330 in the base 33, and a connecting hole 50 is disposed in the slider 34 to connect the second channel 30 with the second damping hole 3130. The flow cross section of the connecting hole 50 is larger than the flow cross section of the second damping hole 3130.

[0053] By setting the installation cavity 330, a space can be provided for the installation and sliding of the slider 34. The connecting hole 50 set in the slider 34 can connect the second channel 30 with the second damping hole 3130, so that when the slider 34 is in the second position, a connecting channel is formed between the second damping hole 3130 and the damping channel 10. In addition, the flow cross section of the connecting hole 50 is set to be larger than the flow cross section of the second damping hole 3130, so that a smaller pressure can be formed in the connecting hole 50, thereby preventing the damping fluid on the side of the piston assembly 3 close to the base 33 from pushing the slider 34 out of the second position, thereby ensuring that the second channel 30 is connected with the second damping hole 3130 and the damping channel 10 respectively.

[0054] In terms of specific structure, the piston cylinder 311 of this embodiment is cylindrical in overall structure, the magnetic drive assembly 32 and the base 33 are connected and abutted, and are respectively arranged at both ends of the piston cylinder 311, and one end of the slider 34 provided on the base 33 is located at one end of the piston cylinder 311. As a preferred embodiment, the first end cover 312 abuts against the magnetic drive assembly 32, and the first end cover 312 is pressed by the limiting edge formed by the inward bending of the corresponding edge of the piston cylinder 311. The second end cover 313 is preferably arranged at the opening of the installation cavity 330, and the second end cover 313 is fixed to the base 33 by the clamping connection of the clamping spring 55 located on the outside of the second end cover 313 with the clamping groove in the installation cavity 330.

[0055] Moreover, the end of the base 33 away from the magnetic drive assembly 32 is also limited by the limiting edge formed by the inward bending of the edge of the piston cylinder 311. At this time, the setting of the limiting edges at both ends of the piston cylinder 311 can better limit the first end cover 312, the magnetic drive assembly 32 and the base 33 in the piston cylinder 311. At the same time, the second end cover 313 is set at the opening of the installation cavity 330, which can also limit the movement of the slider 34, ensuring the movement of the slider 34 between the first position and the second position. The setting of the position of the second end cover 313 can also save the material of the second end cover 313 and reduce the manufacturing cost.

[0056] It is understandable that the second end cover 313 may also be disposed at an end of the base 33 away from the magnetic drive assembly 32 and abut against the limiting edge of the piston cylinder 311 . This is also possible.

[0057] The magnetic drive assembly 32 of this embodiment specifically includes an iron core 321 fixed to the end of the piston rod 2, and an electromagnetic coil 322 sleeved on the iron core 321. The gap formed between the outer peripheral surface of the iron core 321 and the inner wall of the piston cylinder 311 constitutes the above-mentioned damping channel 10, and one end of the damping channel 10 is connected to the first damping hole 3120 on the first end cover 312. The electrical connector 21 in the piston rod 2 passes through the iron core 321 and is electrically connected to the electromagnetic coil 322.

[0058] Specifically, the iron core 321 and the end of the piston rod 2 can be fixedly connected by screw connection or clamping of a clamping spring 55. In addition, the electrical connector 21 in the piston rod 2 is preferably a wire, and the end of the wire has a T-shaped clamping block 210, and the clamping block 210 is clamped in the clamping groove on the iron core 321. In addition, the iron core 321 is provided with a through hole (not shown in the figure), and the wire passes through the through hole and is electrically connected to the electromagnetic coil 322, so that the electromagnetic coil 322 can be made conductive by connecting an external power source with the wire.

[0059] As a preferred embodiment, in this embodiment, a connecting channel 40 communicating with the damping channel 10 is also provided in the base 33, and the first channel 20 and the second channel 30 are connected in parallel between the connecting channel 40 and the mounting cavity 330. At this time, the setting of the connecting channel 40 and the first channel 20 and the second channel 30 arranged in parallel are conducive to the processing and forming of the connecting channel 40, the first channel 20 and the second channel 30, so that the overall structure of the base 33 is relatively simple.

[0060] In a specific implementation, the installation cavity 330 is formed in the middle of the base 33, the first channel 20 and the second channel 30 are arranged at intervals along the axial direction of the base 33, and the first channel 20 and the second channel 30 are both extended to the installation cavity 330 along the radial direction of the base 33 to communicate with the installation cavity 330 respectively. And as a preferred embodiment, the first channel 20 and the second channel 30 are multiple and are arranged on the base 33, and each of the first channel 20 and each of the second channels 30 are communicated with the installation cavity 330. The connecting channel 40 extends from the end of the base 33 away from the opening of the installation cavity 330 along the axial direction of the base 33, and is a plurality of connecting channels 40 arranged at intervals along the circumferential direction of the base 33, one end of each of the connecting channels 40 is communicated with the first channel 20 and the second channel 30, and the other end of each of the connecting channels is communicated with the damping channel 10.

[0061] In this embodiment, an elastic reset member 35 is also provided between the slider 34 and the base 33. The elastic reset member 35 can store energy when the slider 34 slides from the second position to the first position, and when the elastic reset member 35 releases energy, it can drive the slider 34 to slide from the first position to the second position. That is, when the electromagnetic coil 322 is energized, under the action of magnetic force, the slider 34 slides from the second position to the first position, and the elastic reset member 35 is compressed to store energy. When the electromagnetic coil 322 is de-energized, the elastic reset member 35 releases energy and drives the slider 34 to slide from the first position to the second position.

[0062] At this time, the setting of the elastic reset member 35 and the use of the energy release of the elastic reset member 35 enable the slider 34 to slide smoothly from the first position to the second position, and can also save the reverse current passed into the magnetic drive component 32, save electric energy, and have a low manufacturing cost. In addition, in a specific implementation, the elastic reset member 35 is preferably a spring, and the two ends of the spring are respectively connected to the slider 34 and the base 33.

[0063] Still viewing Figure 2 and Figure 3 As a preference, in this embodiment, a first sealing member 331 is also provided on the base 33 to seal between the base 33 and the piston cylinder 311. Specifically, the first sealing member 331 includes a first sealing ring sleeved on the outer peripheral surface of the base 33, and the first sealing rings are preferably arranged in two intervals along the axial direction of the base 33. The oil ports of the first channel 20 and the second channel 30 formed on the outer peripheral surface of the base 33 are located between the two first sealing rings, so that the damping fluid in the first channel 20 and the second channel 30 can be effectively prevented from leaking through the gap between the base 33 and the piston cylinder 311.

[0064] Also preferably, in this embodiment, a second sealing member 341 is also provided between the slider 34 and the base 33, and the second sealing member 341 is used to seal the gap between the first channel 20 and the second channel 30. Specifically, the second sealing member 341 includes a second sealing ring sleeved on the outer peripheral surface of the slider 34, and the second sealing rings are preferably arranged at intervals along the moving direction of the slider 34. When the slider 34 is in the first position, the oil port communicating with the second channel 30 and the mounting cavity 330 is located between the two second sealing rings. When the slider 34 is in the second position, the oil port communicating with the first channel 20 and the mounting cavity 330 is also located between the two second sealing rings. In this way, when the slider 34 is in the first position and the second position, respectively, the first channel 20 and the second channel 30 are better isolated.

[0065] The piston assembly 3 of this embodiment is provided with a slider 34 to receive the drive of the magnetic driving assembly 32 to slide between the first position and the second position, and when the slider 34 is located at the first position and the second position, different damping paths are formed between the first damping hole 3120 and the second damping hole 3130. Moreover, when the piston assembly 3 is applied to a magnetorheological shock absorber, when the electromagnetic coil 322 is energized, the damping fluid passes through the first channel 20 with a larger flow section, and the viscosity of the damping fluid is adjusted by adjusting the energized current to adjust the damping force; when the electromagnetic coil 322 is powered off or a power failure occurs, the damping fluid passes through the second channel 30 with a smaller flow section, so that the shock absorber can provide the necessary damping force when the power is off or the power fails.

[0066] Embodiment 2

[0067] This embodiment relates to a magnetorheological damper, such as Figure 1 As shown, a floating piston 4 and a piston assembly 3 of the first embodiment are slidably arranged in the cylinder 1 of the magnetorheological damper of this embodiment. The floating piston 4 separates the cavity in the cylinder 1 into an air cavity 100 and a liquid cavity 200. The air cavity 100 is provided with high-pressure gas, and the liquid cavity 200 is provided with magnetorheological fluid. The piston assembly 3 is arranged in the liquid cavity 200, and the piston assembly 3 can move in the cylinder 1 along with the movement of the piston rod 2, and both ends of the piston assembly 3 are damping liquid cavities 200.

[0068] In this embodiment, see Figure 4 Combined with Figure 1 As shown, a third sealing member 401 is provided between the floating piston 4 and the cylinder 1. The third sealing member 401 is preferably a third sealing ring sleeved on the floating piston 4, and the third sealing ring is used to seal the gap between the floating piston 4 and the cylinder 1 to ensure the sealing effect between the air cavity 100 and the liquid cavity 200. Moreover, in this embodiment, a lubricating member 402 is also provided between the floating piston 4 and the cylinder 1. The lubricating member 402 is made of a self-lubricating material, wherein the self-lubricating material can be, for example, polytetrafluoroethylene or polyetheretherketone. At this time, by providing the lubricating member 402 between the floating piston 4 and the cylinder 1 and making the lubricating member 402 made of a self-lubricating material, the friction resistance of the floating piston 4 when moving can be reduced, so that during the movement of the piston rod 2, the volume of the air cavity 100 or the liquid cavity 200 can be timely compensated by the movement of the floating piston 4.

[0069] See also Figure 1 and Figure 5 As shown, in this embodiment, an oil seal guide assembly 5 is also provided at the end of the cylinder 1 away from the air chamber 100. The oil seal guide assembly 5 has a sealing component for sealing between the piston rod 2 and the cylinder 1, and a guide member 52 for guiding the movement of the piston rod 2.

[0070] Specifically, the oil seal guide assembly 5 is fixed to one end of the cylinder 1 where the piston rod 2 is provided. The oil seal guide assembly 5 has a guide 51 with a through hole, and the sealing component specifically includes an oil seal 53 provided at one end of the through hole and a sealing ring at the other end. The oil seal 53 is pressed against the outer peripheral surface of the piston rod 2, and a cover plate 54 is provided on one side of the oil seal 53 close to the end of the cylinder 1, and the cover plate 54 is fixed to the cylinder 1 through a retaining ring 55, so that the oil seal is fixed to the guide 51.

[0071] In addition, the guide member 52 is also arranged in the through hole and is located on the side of the oil seal away from the end of the cylinder 1, and the inner wall of the guide member 52 is in clearance fit with the outer peripheral surface of the piston rod 2. In addition, a fourth sealing member 56 is also arranged between the guide 51 and the inner wall of the cylinder 1, and the fourth sealing member 56 is preferably a sealing ring when it is implemented.

[0072] In addition, it is worth noting that the magnetorheological shock absorber of this embodiment can be used in the suspension system of a vehicle, and of course can also be used in other equipment that needs to provide damping force.

[0073] Based on the prior art, due to the magnetic field and fluid characteristics, the damping provided by the magnetorheological damper increases with the increase of current. When there is no current, the damping of the magnetorheological damper is the lowest. However, when the circuit system fails, that is, when the magnetorheological damper is in a power-off or power supply abnormality situation, its damping is the lowest. For the suspension system using the magnetorheological damper, the existing magnetorheological damper cannot provide sufficient damping, which can easily lead to unsafe situations such as severe vehicle roll when turning and increased braking distance during emergency braking, and cannot well ensure the safety of the driver and the vehicle.

[0074] The magnetorheological shock absorber of this embodiment adopts the piston assembly 3 of the first embodiment, so that when the magnetorheological shock absorber is powered on, the magnitude of the input current is used to achieve rapid adjustment of the damping. Moreover, when the power is off or the power supply is abnormal, the magnetorheological shock absorber can still provide a certain damping force through the conduction between the second channel 30 and the second damping hole 3130 provided in the piston assembly 3. In particular, when the magnetorheological shock absorber is used in the suspension system of the vehicle, the occurrence of unsafe situations due to insufficient damping can be avoided, thereby ensuring the safety of the driver and the vehicle, and having a good use effect.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A piston assembly, characterized in that: It comprises a piston housing (31) with a first damping hole (3120) and a second damping hole (3130) respectively provided at two ends, and a magnetic driving component (32) and a base (33) provided in the piston housing (31); The magnetic drive component (32) is fixed on the piston rod (2) and is electrically connected to the electrical connector (21) in the piston rod (2); a damping channel (10) is formed between the magnetic drive component (32) and the piston housing (31); one end of the damping channel (10) is in communication with the first damping hole (3120); The base (33) is provided with a first channel (20) and a second channel (30), the flow cross section of the second channel (30) is smaller than the flow cross sections of the first channel (20) and the damping channel (10), and the base (33) is provided with a slider (34), the slider (34) is driven by the magnetic drive component (32) and can slide between a first position and a second position in the base (33); When the slider (34) is in the first position, the other end of the damping channel (10) is connected to the second damping hole (3130) through the first channel (20); when the slider (34) is in the second position, the other end of the damping channel (10) is connected to the second damping hole (3130) through the second channel (30).

2. The piston assembly according to claim 1, characterized in that: The slider (34) is slidably disposed in the mounting cavity (330) in the base (33), and a connecting hole (50) for connecting the second channel (30) with the second damping hole (3130) is provided in the slider (34); The flow cross section of the connecting hole (50) is larger than the flow cross section of the second damping hole (3130).

3. The piston assembly according to claim 2, characterized in that: The base (33) is provided with a connecting channel (40) in communication with the damping channel (10); The first channel (20) and the second channel (30) are connected in parallel between the connecting channel (40) and the mounting cavity (330).

4. The piston assembly according to claim 1, characterized in that: An elastic reset member (35) is provided between the slider (34) and the base (33); The elastic reset member (35) can store energy when the slider (34) slides from the second position to the first position, and when the elastic reset member (35) releases energy, it can drive the slider (34) to slide from the first position to the second position.

5. The piston assembly according to claim 1, characterized in that: The magnetic drive assembly (32) comprises an iron core (321) fixed on the piston rod (2), and an electromagnetic coil (322) sleeved on the iron core (321); The electrical connector (21) in the piston rod (2) passes through the iron core (321) and is electrically connected to the electromagnetic coil (322).

6. The piston assembly according to any one of claims 1 to 5, characterized in that: The piston housing (31) comprises a piston cylinder (311), and a first end cover (312) and a second end cover (313) provided at both ends of the piston cylinder (311); The first damping hole (3120) is arranged on the first end cover (312), the second damping hole (3130) is arranged on the second end cover (313), and the magnetic drive component (32), the base (33), the first end cover (312) and the second end cover (313) are located in the piston cylinder (311).

7. The piston assembly according to claim 6, characterized in that: The base (33) is provided with a first sealing member (331) for sealing between the base (33) and the piston cylinder (311); and / or, A second sealing member (341) is provided between the sliding block (34) and the base (33), and the second sealing member (341) is used to seal the gap between the first channel (20) and the second channel (30).

8. A magnetorheological damper, characterized in that: A floating piston (4) is slidably provided in the cylinder (1) of the magnetorheological shock absorber, and a piston assembly (3) according to any one of claims 1 to 7; The floating piston (4) separates the cavity in the cylinder (1) into an air cavity (100) and a liquid cavity (200); gas is arranged in the air cavity (100); magnetorheological fluid is arranged in the liquid cavity (200); and the piston assembly (3) is arranged in the liquid cavity (200).

9. The magnetorheological damper according to claim 8, characterized in that: A third sealing member (401) is provided between the floating piston (4) and the cylinder barrel (1), and the third sealing member (401) is used to seal the gap between the floating piston (4) and the cylinder barrel (1); and / or, A lubricating element (402) is provided between the floating piston (4) and the cylinder barrel (1), and the lubricating element (402) is made of a self-lubricating material.

10. The magnetorheological damper according to claim 8, characterized in that: An oil seal guide assembly (5) is provided at one end of the cylinder barrel (1) away from the air chamber (100), and the oil seal guide assembly (5) comprises a sealing component for sealing between the piston rod (2) and the cylinder barrel (1), and a guide member (52) for guiding the movement of the piston rod (2).

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