Damper of magneto-rheological shock absorber

Abstract

The damper comprises an outer shell, a piston, an upper end cover, a lower end cover, a closing piece and a pre-pressing applying piece, the piston is fixedly installed in the outer shell through the upper end cover and the lower end cover, and a first channel is formed in a gap between the piston and the inner wall of the outer shell. The upper end cover and the lower end cover are respectively provided with an upper main through hole and a lower main through hole for the magnetorheological fluid to flow through; a second channel is formed in the piston, the upper end cover and the lower end cover are provided with a previous through hole and a next through hole respectively, the second channel is communicated with the previous through hole and the next through hole respectively, the closing piece abuts against the previous through hole, and the pre-pressing applying piece is used for applying pre-tightening force to the closing piece so that the previous through hole can be in a closed state. A bypass hole is formed in the closing piece, and the inner diameter of the bypass hole is smaller than that of the previous through hole. The asymmetric controllable damping device is simple in structure, can realize asymmetric controllable damping force, and also has a bypass function.

Description

Technical Field

[0001] The utility model relates to the technical field of shock absorbers, in particular to a damper of a magnetorheological shock absorber. Background Art

[0002] As a new type of intelligent shock absorber, magnetorheological (MR) dampers offer advantages such as fast response, a wide range of damping force adjustment, and low energy consumption. When used in vehicle damping systems, they effectively attenuate the transmission of vibrations between the wheels and the road surface, improving ride and driving comfort. Consequently, they are increasingly widely used in the field of vehicle shock absorbers. Conventional MR dampers typically incorporate a bypass channel within the piston to reduce damping force, in addition to a primary channel. The MR fluid can flow through both the primary and secondary channels. Furthermore, to achieve asymmetric compression and recovery damping forces, a secondary channel must be added to the damper, equipped with a closed valve assembly. Due to the relatively small size of the damper, the simultaneous inclusion of both the secondary and secondary channels increases manufacturing requirements, leading to a high defect rate and further cost increases. Utility Model Content

[0003] The purpose of the utility model is to provide a damper for a magnetorheological vibration absorber, aiming to solve the problems in existing magnetorheological vibration absorbers that the damper is small in size, a bypass channel and a second channel are provided, the processing and production requirements for the damper are relatively high, and the defective rate of the damper is high.

[0004] In order to achieve the above-mentioned purpose, the utility model discloses a damper of a magnetorheological vibration absorber, comprising a shell, a piston, an upper end cover, a lower end cover, a closing plate and a pre-pressure applying member, the upper end cover and the lower end cover fix the piston in the shell, the gap between the piston and the inner wall of the shell forms a first channel, the upper end cover and the lower end cover are respectively provided with an upper main through hole and a lower main through hole for the circulation of magnetorheological fluid; a second channel is provided in the piston, the upper end cover and the lower end cover are respectively provided with an upper through hole and a lower through hole, the second channel is respectively connected to the upper through hole and the lower through hole, the closing plate abuts against the upper through hole, the pre-pressure applying member is used to apply a pre-tightening force to the closing plate so that the upper through hole is in a closed state, the closing plate is provided with a bypass hole, the inner diameter of the bypass hole is smaller than the inner diameter of the upper through hole.

[0005] Preferably, the closing piece is annular, and there are a plurality of bypass holes, all of which are distributed in an annular shape around the axis of the closing piece.

[0006] Preferably, the bypass hole is provided between the outer peripheral wall and the inner peripheral wall of the closing piece.

[0007] The beneficial effects of the present invention are as follows: the damper of the magnetorheological shock absorber provided by the above technical solution, when the damper is in a low-speed compression stroke, the magnetorheological fluid can flow through the first channel and also enter the second channel, the magnetorheological fluid in the second channel flows through the bypass hole, the magnetorheological fluid with a lower speed cannot overcome the preload force applied by the preload applying member to the closing piece, and the damper can also generate a smaller damping force when the damper moves at a low speed. The damper is applied to the magnetorheological shock absorber of an automobile to improve the rolling comfort of the vehicle at a low speed; when the damper is in a high-speed compression stroke, the magnetorheological fluid can flow through the first channel and also enter the second channel, and the second channel The magnetorheological fluid inside circulates through the bypass hole, and the magnetorheological fluid with higher speed overcomes the preload force applied by the preload applying member to the closing plate, opens the closing plate, and the damping force generated by the shock absorber is relatively small; during the rebound stroke, the closing plate closes the previous through hole. Since the inner diameter of the bypass hole is much smaller than the inner diameter of the previous through hole, most of the magnetorheological fluid circulates through the first channel, and the damping force generated by the shock absorber is relatively large. The utility model has a simple structure, can realize asymmetric controllable damping force, and has the function of bypass, so as to solve the problem that the damper in the existing magnetorheological shock absorber is small in size, and the bypass channel and the second channel are opened at the same time, the processing and production requirements of the damper are relatively high, and the defective rate of the damper is relatively high.

[0008] The present invention will become more clear through the following description in conjunction with the accompanying drawings, which are used to explain embodiments of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Shown is the overall structural diagram of the damper.

[0010] Figure 2 Shown Figure 1 Cross-sectional view of AA in the figure.

[0011] Figure 3 Shown is a structural separation diagram of the damper.

[0012] Figure 4 Shown is a structural separation diagram of the upper end cover and valve assembly.

[0013] Figure 5 Shown is a top view of the upper end cap.

[0014] Figure 6 Shown is a cross-sectional view of BB in 5.

[0015] Figure 7 Shown is a structural separation diagram of the lower end cover and throat plug.

[0016] Figure 8 Shown is a cross-sectional view after the lower end cover and throat plug are separated.

[0017] Figure 9 Shown is a cross-sectional view of a magnetorheological damper. DETAILED DESCRIPTION

[0018] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0019] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0020] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0021] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0022] refer to Figures 1 to 8A damper includes a housing 100, a piston 400, a piston rod 500, an upper end cover 300, a lower end cover 200 and a valve assembly. The upper end cover 300 and the lower end cover 200 fix the piston 400 in the housing 100 at the upper and lower ends. The gap between the piston 400 and the inner wall of the housing 100 forms a first channel 110. The upper end cover 300 and the lower end cover 200 are respectively provided with an upper main through hole 301 and a lower main through hole 201. The first channel 110 is connected to the upper main through hole 301 and the lower main through hole 201. The piston rod 500 passes through the upper end cover 300 and is fixedly connected to the piston 400. A second channel 401 is provided in the piston 400. The upper end cover 300 and the lower end cover 200 are respectively provided with an upper through hole 302 and a lower through hole 202. The second channel 401 is connected to the upper through hole 302 and the lower through hole 202 respectively. The valve assembly is provided above the upper end cover 300. The valve assembly is used to cover the upper through hole 302. The valve assembly is a closing structure that can open the upper through hole 302 under the pressure of the magnetorheological fluid. During the compression stroke, the magnetorheological fluid can flow through the first channel 110 and can also enter the second channel 401. The magnetorheological fluid in the second channel 401 opens the closing structure of the upper through hole 302, as shown in FIG. Figure 2 As shown by the arrow in , the damping force generated by the shock absorber is relatively small at this time; during the rebound stroke, the valve assembly closes the upper through hole 302, the magnetorheological fluid cannot flow through the second channel 401, and the magnetorheological fluid can only flow through the first channel 110. At this time, the damping force generated by the shock absorber is relatively large; the utility model has a simple structure, realizes asymmetric controllable damping force, and solves the problem of asymmetry between compression and recovery damping forces of the damper in the existing magnetorheological shock absorber.

[0023] In one embodiment, a plurality of second channels 401 are provided in the piston 400, and the upper end cover 300 and the lower end cover 200 are respectively provided with a plurality of upper through holes 302 and a plurality of lower through holes 202, and the upper end cover 300 and the lower end cover 200 are connected to the second channels 401 in a one-to-one correspondence; and a plurality of throat plug groups are also included, and the throat plug group includes throat plugs 210 whose number is the same as the lower through holes 202, and the throat plugs 210 are detachably installed in the lower through holes 202, and throat plug through holes 211 are provided in the throat plugs 210, and the inner diameters of the throat plug through holes 211 of the throat plugs 210 in the same throat plug group are the same, and the inner diameters of the throat plug through holes 211 of the throat plugs 210 in the two groups of throat plug groups are different. A plurality of second channels 401 are provided in the piston 400, and all the second channels 401 are arranged in a ring-shaped distribution around the axis of the piston 400. During the compression stroke, the magnetorheological fluid enters the second channels 401, so that the damper is subjected to uniform force, thereby preventing the damper from being subjected to uneven force and generating radial force that damages the connection structure of the piston rod 500, the piston 400 and the shock absorber cylinder, thereby ensuring the service life. Since the apertures of the upper through hole 302, the lower through hole 202 and the second channel 401 remain unchanged, the flow rate of the magnetorheological fluid flowing through the second channel 401 in the conventional shock absorber is constant. When testing or producing the shock absorber, in response to different damping force requirements, this embodiment provides multiple groups of throat plug groups, and the throat plug group includes throat plugs 210 with the same number as the lower through holes 202. The throat plugs 210 are detachably installed in the lower through holes 202. The throat plugs 210 are provided with throat plug through holes 211. The inner diameters of the throat plug through holes 211 of the throat plugs 210 in the same throat plug group are the same; when different damping force requirements are required, all the throat plugs 210 can be removed from the lower through holes 202, and a throat plug group with a suitable inner diameter of the throat plug through holes 211 is selected, and then the throat plugs 210 of this group are installed one by one in the lower through holes 202. An internal thread can be machined into the secondary through-hole 202, and an external thread can be machined into the outer peripheral wall of the throat plug 210, so that the throat plug 210 can be detachably connected to the secondary through-hole 202 by screwing the threads together. To facilitate installation and removal, the two side ports of the throat plug 210 can also be machined into internal hexagonal holes, and the throat plug through-hole 211 is located between the two side ports, so that the throat plug 210 can be removed and installed using a conventional internal hexagonal wrench. In addition, since the two side ports of the throat plug 210 are machined into internal hexagonal holes, the installation direction of the throat plug 210 does not need to be considered during installation, further improving installation convenience.

[0024] In one embodiment, a plug group is further included, wherein the plug group includes plugs of the same number as the secondary through-holes 202, and the plugs are detachably installed in the secondary through-holes 202. When testing or producing shock absorbers, depending on different damping force requirements, it is sometimes not necessary for the magnetorheological fluid to flow through the second channel 401. This embodiment also provides a plug group, the structure of which is similar to that of the throat plug 210, in that external threads are machined on the outer peripheral wall, and the plug is detachably connected to the secondary through-hole 202 by screwing the threads together; the two side ports of the plug are machined into hexagonal inner holes, and the space between the hexagonal inner holes of the two side ports is a solid structure, thereby sealing the secondary through-hole 202.

[0025] In one embodiment, a sealing assembly is further included, which includes an upper seal 410 and a lower seal 420. The upper end cover 300 is sealedly connected to the upper part of the piston 400 through the upper seal 410; the lower end cover 200 is sealedly connected to the lower part of the piston 400 through the lower seal 420. During the compression stroke, the magnetorheological fluid can flow through the first channel 110 and enter the second channel 401. The magnetorheological fluid in the second channel 401 opens the closing structure of the previous through hole 302. To prevent the magnetorheological fluid from entering the second channel 401, the valve assembly that does not open the previous through hole 302 flows into the first channel 110 along the gap between the upper end cover 300 and the piston 400, or the gap between the lower end cover 200 and the piston 400. A sealing assembly is required. The sealing assembly includes an upper seal 410 and a lower seal 420. The upper end cover 300 and the upper part of the piston 400 are sealed together by the upper seal 410; the lower end cover 200 and the lower part of the piston 400 are sealed together by the lower seal 420. Both the upper seal 410 and the lower seal 420 can be in the form of a sealing gasket or a sealing ring. The upper and lower end surfaces of the piston 400 can be provided with grooves, and the lower part of the upper end cover 300 and the upper part of the lower end cover 200 are provided with bosses. Through the cooperation of the bosses and the grooves, the coaxiality of the upper end cover 300, the piston 400 and the lower end cover 200 is improved. When the upper seal 410 and the lower seal 420 use sealing gaskets, they can be respectively mounted on the lower part of the upper end cover 300 and the upper part of the bosses of the lower end cover 200; when the upper seal 410 and the lower seal 420 use sealing rings, sealing ring grooves need to be processed on the lower part of the upper end cover 300, the upper part of the lower end cover 200, and the upper and lower end surfaces of the piston 400, and then the sealing rings are placed in the sealing ring grooves for sealing.

[0026] In one embodiment, the valve assembly includes a closing disc 310, a preload member 320, and a retainer 330. The closing disc 310 is used to shield the upper through hole 302. The retainer 330 is fixed to the piston rod 500. The ends of the preload member 320 respectively abut the closing disc 310 and the retainer 330. The preload member 320 is used to apply a preload force to the closing disc 310 to keep the upper through hole 302 in a closed state. The closing disc 310 has a circular ring structure. The ends of the preload member 320 respectively abut the closing disc 310 and the retainer 330. The preload member 320 is used to apply a preload force to the closing disc 310 to keep the upper through hole 302 in a closed state. The preload member 320 can adopt a tower spring structure, which has a large compression capacity. Therefore, using a shorter tower spring can achieve a larger opening range of the upper through hole 302, making the valve assembly compact and stable. The upper portion of the upper end cover 300 is axially extended upward to form an upper pipe section 304. The outer peripheral wall of the upper pipe section 304 is radially extended outward to form a circle of annular grooves 303. The upper portion of the upper pipe section 304 is provided with an external thread. The upper portion of the retainer 330 is a nut structure with an internal thread. The lower portion of the retainer 330 is axially extended downward to form a lower pipe section 331. The retainer 330 is detachably connected to the upper end cover 300 by screwing. The retainer 330 is mounted on the upper end cover 300. 00, the lower tube section 331 of the retainer 330 can extend into the annular groove 303. After the retainer 330 is installed on the upper end cover 300, a certain gap is left between the lower end surface of the lower tube section 331 and the bottom surface of the annular groove 303. This prevents the retainer 330 from being restricted from further downward rotation after the lower end surface of the lower tube section 331 abuts the bottom surface of the annular groove 303 during installation, resulting in the closure plate 310 not being able to apply the preset preload force by the tower spring. In addition, the closure plate 310 adopts a circular ring structure and is sleeved on the lower tube section 331. The lower tube section 331 and the closure plate 310 have a clearance fit, and the lower tube section 331 serves as a vertical guide for the closure plate 310.

[0027] In one embodiment, the upper portion of the upper end cap 300 is provided with two crimping surfaces 305, the upper through hole 302 is disposed between the two crimping surfaces 305, and the lower end surface of the closing piece 310 is simultaneously abutted against both crimping surfaces 305. The upper through hole 302 is disposed between the two crimping surfaces 305, and the two crimping surfaces 305 are provided to support the closing piece 310. To reduce weight and cost, an annular groove is provided between the two crimping surfaces 305, and the upper through hole 302 is disposed at the bottom of the annular groove. The closing piece 310 has a circular ring structure, and the lower end surface of the closing piece 310 simultaneously abuts against both crimping surfaces 305, thereby shielding the upper through hole 302.

[0028] In one embodiment, a support step 306 is provided between the two crimping surfaces 305. To increase the strength of the upper end cover 300 and prevent the closing piece 310 from being pressed into the annular groove, multiple support steps 306 are provided at intervals within the annular groove. All support steps 306 are arranged in an annular pattern along the axis of the upper end cover 300.

[0029] In one embodiment, the closing piece 310 is provided with a bypass hole 311. Under the force of the preload member 320, the closing piece 310 abuts against the two crimping surfaces 305. The bypass hole 311 is connected to the previous through hole 302. Several bypass holes 311 with smaller apertures are spaced apart on the closing piece 310. Under the force of the preload member 320, the closing piece 310 abuts against the two crimping surfaces 305. The bypass holes 311 are connected to the previous through hole 302. When the force applied by the magnetorheological fluid does not reach the force required to open the preload member 320, a small amount of magnetorheological fluid can flow through the second channel 401, the previous through hole 302, and the bypass hole 311. This allows the damper to generate a small damping force even at low speeds. This damper can be used in a magnetorheological shock absorber in an automobile to improve the vehicle's rolling comfort at low speeds.

[0030] refer to Figure 9This embodiment further discloses a magnetorheological damper, comprising a cylinder 600 with an opening at one end, a guide seat 660 being provided at the opening of the cylinder 600, and the damper as described above, wherein the damper divides the cylinder 600 into a compression chamber 630 and a rebound chamber 620, and the piston rod 500 extends out of the cylinder 600 through the guide seat 660; the upper main through hole 301 is connected to the rebound chamber 620; and the lower main through hole 201 and the lower through hole 202 are both connected to the compression chamber 630. The damper divides the cylinder 600 into a compression chamber 630 and a rebound chamber 620. The compression chamber 630 and the rebound chamber 620 are filled with magnetorheological fluid. During the compression stroke, the magnetorheological fluid in the compression chamber 630 can flow into the rebound chamber 620 through the first channel 110, and can also enter the second channel 401. The magnetorheological fluid in the second channel 401 opens the closing structure of the previous through hole 302, and the magnetorheological fluid in the compression chamber 630 enters the rebound chamber 620 through the second channel 401. At this time, the damping force generated by the shock absorber is relatively small; during the rebound stroke, the valve assembly closes the previous through hole 302, and the magnetorheological fluid cannot flow through the second channel 401. The magnetorheological fluid in the rebound chamber 620 can only flow into the compression chamber 630 through the first channel 110. At this time, the damping force generated by the shock absorber is relatively large. A floating piston 640 is also provided in the magnetorheological shock absorber. The floating piston 640 divides the compression chamber 630 into a liquid chamber and a gas chamber 650. The floating piston 640 and the bottom of the cylinder 600 form a gas chamber 650, which is filled with high-pressure gas; the liquid chamber is between the floating piston 640 and the damper, which is filled with magnetorheological fluid.

[0031] The above disclosure is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A damper for a magnetorheological vibration absorber, characterized in that: It includes an outer shell, a piston, an upper end cover, a lower end cover, a closing piece and a pre-pressure applying member. The upper end cover and the lower end cover fix the piston in the outer shell. The gap between the piston and the inner wall of the outer shell forms a first channel. The upper end cover and the lower end cover are respectively provided with an upper main through hole and a lower main through hole for the circulation of magnetorheological fluid; a second channel is provided in the piston, and the upper end cover and the lower end cover are respectively provided with an upper through hole and a lower through hole. The second channel is connected to the upper through hole and the lower through hole respectively. The closing piece abuts against the upper through hole. The pre-pressure applying member is used to apply a pre-tightening force to the closing piece to keep the upper through hole in a closed state. The closing piece is provided with a bypass hole, and the inner diameter of the bypass hole is smaller than the inner diameter of the upper through hole.

2. The damper of a magnetorheological vibration absorber according to claim 1, characterized in that: The closing piece is in an annular shape, and there are a plurality of bypass holes, all of which are distributed in an annular shape around the axis of the closing piece.

3. The damper of a magnetorheological vibration absorber according to claim 2, characterized in that: The bypass hole is arranged between the outer peripheral wall and the inner peripheral wall of the closing piece.

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