shock absorbers

Abstract

This invention relates to a shock absorber. According to one aspect of the invention, a shock absorber can be provided, comprising: a cylinder filled with fluid; a piston valve mounted on a reciprocating piston rod inside the cylinder, dividing the space within the cylinder into an extension chamber and a compression chamber; a guide rod disposed at the upper part of the cylinder to guide the movement of the piston rod; a limiter engaged with the outside of the piston rod; and a flow piston valve, through which the piston rod passes, dividing the extension chamber into an upper chamber and a lower chamber, and providing a plurality of bypass flow paths to communicate between the upper and lower chambers. Wherein, when the piston rod is in its extension stroke, the limiter partially abuts against the flow piston valve from the lower part and causes it to rise, thereby regulating the flow rate of fluid through the bypass flow paths.

Description

Technical Field

[0001] This invention relates to a shock absorber, and more specifically, to a shock absorber that can improve ride comfort and reduce noise during rebound (extension) travel. Background Technology

[0002] Vehicles are typically equipped with buffer devices to cushion the impact or vibration that the axle receives from the road surface during driving, thereby improving ride comfort. Shock absorbers are one such buffer device.

[0003] Figure 1 This is a cross-sectional view showing a shock absorber according to the prior art. (Refer to...) Figure 1 The shock absorber 10 is disposed between the axle and the vehicle body and includes a cylinder 12, with a piston rod 14 movably disposed on the cylinder 12. The cylinder 12 can be formed as a single tube or as a double tube structure consisting of an inner tube 12a and an outer tube 12b.

[0004] Furthermore, the guide rod 16 is disposed on the upper part of the cylinder 12 to maintain a constant distance between the inner tube 12a and the outer tube 12b and to guide the movement of the piston rod 14. Additionally, the cylinder 12 is filled with a buffer medium such as a working fluid, which generates a damping force as the oil moves through the piston valve disposed at the end of the piston rod 14.

[0005] This shock absorber 10 has a limiter 20 mounted on the outer side of the piston rod 14. The limiter 20 restricts the piston rod 14 from rising upwards when it is in the overstretch stroke, thereby preventing damage to the piston valve and improving roll characteristics during cornering.

[0006] The limiter 20 can be attached to the piston rod 14 by welding or by assembly. A buffer portion 22 is provided on the upper part of this limiter 20. The buffer portion 22 is formed of an elastic material and contacts the lower end of the guide rod 16, and cushions the impact by deformation.

[0007] The limiter 20 of this conventionally structured shock absorber 10 has a limitation: it does not provide sufficient cushioning force when the piston rod 14 rises excessively. Therefore, when the shock absorber is subjected to frequent high loads, the buffer portion 22 of the limiter 20 may be damaged. This can lead to product malfunction, noise generation, and reduced ride comfort.

[0008] Furthermore, since there is no damping force adjustment function during extended travel, the ride comfort is reduced when the damping force decreases. Summary of the Invention

[0009] (a) Technical problems to be solved

[0010] The shock absorber according to an embodiment of the present invention improves the structure in which the piston rod generates a buffering force by hydraulic pressure when it is in the extension stroke, thereby improving ride comfort, reducing contact noise, and lowering manufacturing costs.

[0011] Furthermore, the shock absorber according to an embodiment of the present invention is configured to be applicable to ordinary shock absorbers, thereby improving ease of assembly and industrial applicability.

[0012] (II) Technical Solution

[0013] According to one aspect of the present invention, a shock absorber can be provided, comprising: a cylinder filled with fluid; a piston valve mounted on a reciprocating piston rod inside the cylinder, dividing the space within the cylinder into an extension chamber and a compression chamber; a guide rod disposed at the upper part of the cylinder to guide the movement of the piston rod; a limiter coupled to the outside of the piston rod; and a flow piston valve coupled through the piston rod, dividing the extension chamber into an upper chamber and a lower chamber, and providing a plurality of bypass flow paths to communicate between the upper and lower chambers. Wherein, when the piston rod is in its extension stroke, the limiter partially abuts against the flow piston valve from the lower part and causes it to rise, thereby regulating the flow rate of fluid through the bypass flow paths.

[0014] Furthermore, the flow piston valve includes: a piston body through which the piston rod passes and forms the bypass flow path on its inner side; a pair of valve blocks through which the piston rod passes and are spaced apart from the upper and lower parts of the piston body by a predetermined distance; and an elastic member disposed between the piston body and the pair of valve blocks, wherein the pair of valve blocks can cause the elastic member to elastically deform and move toward the piston body.

[0015] Furthermore, the piston body may include: an annular first body portion disposed on the piston rod; and a second body portion extending upward and downward from the first body portion and contacting the inner surface of the cylinder.

[0016] Furthermore, the bypass flow path can be formed by a groove that passes through the second main body and is formed on the inner side of the second main body in the vertical direction.

[0017] Furthermore, the upper and lower parts of the second main body can be configured as tapered shapes with the diameter of the inner side gradually decreasing towards the first main body, and the pair of valve blocks can be configured to have tapered shapes so as to contact the inner side surfaces of the upper and lower parts of the second main body, respectively.

[0018] Furthermore, the bypass flow path may include: a first flow path formed on the tapered inclined surface of the second main body; and a second flow path communicating with the first flow path and having a deeper depth than the first flow path.

[0019] Furthermore, the outer diameter of the pair of valve blocks can be set to be located inside the outer end of the first flow path formed in the second main body.

[0020] Furthermore, the elastic member can be formed from an elastically deformable rubber material or a spring.

[0021] Furthermore, it may include a damping device disposed on the upper part of the flow piston valve, which reduces the contact impact of the flow piston valve when the piston rod is in the extension stroke.

[0022] (III) Beneficial Effects

[0023] The shock absorber of the present invention improves the structure of generating a buffering force by hydraulic pressure when the piston rod rebounds, thereby improving ride comfort, reducing contact noise, and lowering manufacturing costs.

[0024] Furthermore, the shock absorber according to an embodiment of the present invention is configured to be applicable to ordinary shock absorbers, thereby improving ease of assembly and industrial applicability.

[0025] Furthermore, the shock absorber according to an embodiment of the present invention is configured with a simple structure, thereby reducing manufacturing costs and being adaptable to various structures, thus making it easy to apply. Attached Figure Description

[0026] The present invention will be described in detail with reference to the following drawings. However, these drawings only illustrate preferred embodiments of the invention, and the technical concept of the invention should not be limited to the drawings.

[0027] Figure 1 This is a cross-sectional view showing a shock absorber according to the prior art.

[0028] Figure 2 This is a cross-sectional view showing a shock absorber according to an embodiment of the present invention.

[0029] Figure 3 This is an exploded perspective view showing a flow piston valve provided in a shock absorber according to an embodiment of the present invention.

[0030] Figure 4 This is a partially enlarged view showing a flow piston valve provided in a shock absorber according to an embodiment of the present invention.

[0031] Figure 5 This is a diagram illustrating another embodiment of an elastic member disposed in the flow piston valve of a shock absorber according to an embodiment of the present invention.

[0032] Figures 6 to 8These are diagrams illustrating the operating states of the flow piston valve when the shock absorber is in its extension stroke according to an embodiment of the present invention.

[0033] Figures 9 to 11 These are figures illustrating embodiments of the damping devices provided in the shock absorbers according to the present invention.

[0034] Explanation of reference numerals in the attached figures

[0035] 1: Shock absorber 100: Cylinder

[0036] 130: Piston rod 140: Piston valve

[0037] 150: Guide rod; 160: Limiter

[0038] 200: Flow piston valve; 210: Piston body

[0039] 220: Bypass flow path; 231, 232: Valve block

[0040] 240: Elastic component; 310, 320, 330: Damping device Detailed Implementation

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are provided to fully convey the spirit of the invention to those skilled in the art. The invention is not limited to the embodiments presented herein and may be embodied in other forms. In the drawings, parts unrelated to the description may be omitted to clarify the invention, and the size of components may be appropriately enlarged to aid understanding.

[0042] Figure 2 This is a cross-sectional view showing a shock absorber according to an embodiment of the present invention. Figure 3 This is an exploded perspective view showing a flow piston valve provided in a shock absorber according to an embodiment of the present invention. Figure 4 This is a partially enlarged view showing a flow piston valve provided in a shock absorber according to an embodiment of the present invention.

[0043] Reference Figures 2 to 4 According to one aspect of the present invention, the shock absorber 1 may include: a cylinder 100 filled with fluid; a piston valve 140 dividing the interior of the cylinder 100 into a compression chamber 110 and a tension chamber 120; a piston rod 130 coupled to the piston valve 140 and reciprocating within the cylinder 100; a guide rod 150 disposed on the upper part of the cylinder 100 to guide the movement of the piston rod 130; a flow piston valve 200 mounted on the piston rod 130; and a limiter 160 adjusting the flow rate of fluid through a bypass flow path 220 formed in the flow piston valve 200 according to the operation of the piston rod 130.

[0044] The cylinder 100 can have a double-acting structure consisting of an inner tube 101 and an outer tube 102, and a guide rod 150 for guiding the piston rod 130 can be provided at the upper end of the cylinder 100. Preferably, the shock absorber 1 of the present invention is applied to the double-acting structure; however, it can also be applied to a single-acting shock absorber with one cylinder.

[0045] This internal tube 101 can be divided into an upper extension chamber 120 and a lower compression chamber 110 by a piston valve 140. The fluid filling the extension chamber 120 and the compression chamber 110 selectively moves relative to each other through the extension flow path (not shown) and compression flow path (not shown) formed in the piston valve 140, thereby generating a damping force due to fluid resistance. That is, the fluid moves upward or downward through the flow path of the piston valve 140, and a damping force due to resistance is generated during the fluid's movement in the direction of the extension and compression strokes.

[0046] The structure described above, in which the piston valve 140 moves together with the piston rod 130 within the cylinder 100 of the shock absorber 1 to generate damping force, is a well-known technique, and therefore a detailed description will be omitted.

[0047] According to one aspect of the invention, the flow piston valve 200 of the shock absorber 1 is coupled to the piston rod 130, dividing the extension chamber 120 into an upper chamber 121 and a lower chamber 122. That is, the flow piston valve 200 is configured to engage with the piston rod 130 on the upper side of the piston valve 140. In this case, a limiter 160 can be disposed between the flow piston valve 200 and the piston valve 140. The limiter 160 can be configured to be fixedly coupled to the outside of the piston rod 130 and move together with the piston rod 130 during operation. This limiter 160 restricts the movement distance of the piston valve 140 during over-extension stroke and can have the same structure as known limiters for preventing damage. However, it should be understood that the difference with the limiter 160 according to one aspect of the invention is that it is operated by applying pressure to the flow piston valve 200 according to the operation of the piston rod 130.

[0048] The flow piston valve 200 can be configured to be engaged by the piston rod 130 passing through its center. More specifically, the flow piston valve 200 may include: a piston body 210; a pair of valve blocks 231, 232, respectively disposed at the upper and lower parts of the piston body 210; and an elastic member 240 disposed between the pair of valve blocks 231, 232 and the piston body 210.

[0049] Multiple bypass flow paths 220 can be provided in the piston body 210 to connect the upper chamber 121 and the lower chamber 122. Such piston body 210 may include: an annular first body portion 211 disposed in the piston rod 130; and a second body portion 212 extending upward and downward from the first body portion 211.

[0050] The first main body 211 can be configured to be joined by the piston rod 130 passing through it.

[0051] The second main body portion 212 is integral with the first main body portion 211, and its outer surface can be configured to contact the inner surface of the cylinder 100, i.e., the inner surface of the inner tube 101. This is to prevent fluid from flowing between the outer side of the piston body 210 and the inner side of the inner tube 101. The upper and lower portions of this second main body portion 212 can be configured as a tapered shape with a diameter that gradually decreases towards the first main body portion 211. That is, the inner sides of the upper and lower portions of the second main body portion 212 are configured to have inclined surfaces 213 in the oblique direction.

[0052] The bypass flow path 220 formed on the piston body 210 can be formed in multiples at predetermined intervals along the circumferential direction of the piston body 210. As described above, the bypass flow path 220 can be formed by passing through the piston body 210 in the vertical direction to connect the upper chamber 121 and the lower chamber 122, which are divided with reference to the flow piston valve 200. More specifically, the bypass flow path 220 can be formed by a groove formed on the inner side of the second body portion 212 in the vertical direction. In this case, since the second body portion 212 is formed by extending from the first body portion 211 in the vertical direction, a portion of the groove is configured to pass through the second body portion. This bypass flow path 220 can include: a first flow path 221 formed on the tapered inclined surface 213 on the upper and lower sides of the second body portion 212; and a second flow path 222 formed by passing through the second body portion 212 in the vertical direction to communicate with the first flow path 221. In this case, the second flow path 222 can be configured to have a deeper depth than the first flow path 221.

[0053] Since this bypass flow path 220 has a second flow path 222 in the vertical direction and a first flow path 221 formed by an oblique line in the radial direction with the second flow path 222 as a reference, the pressure applied to the piston body 210 with the flow of oil can be dispersed.

[0054] A pair of valve blocks 231 and 232 can be divided into an upper valve block 231 disposed on the upper part of the piston body 210 and a lower valve block 232 disposed on the lower part of the piston body 210. The upper valve block 231 and the lower valve block 232 have the same structure. Such a pair of valve blocks 231 and 232 can be configured to have a conical shape so as to contact the inner surface surfaces of the upper and lower parts of the second body part 212, respectively.

[0055] Furthermore, the pair of valve blocks 231, 232 are positioned at a predetermined distance from the piston body 210, and the elastic member 240 can be compressed by applying pressure to move it toward the piston body 210. The outer diameter of the pair of valve blocks 231, 232 can be set to be located inside the outer end portion of the first flow path 221 formed in the second body portion 212. That is, the outermost end portion of the pair of valve blocks 231, 232 is located inside the outer end portion of the first flow path 221. Therefore, even if the pair of valve blocks 231, 232 are in contact with the piston body 210, a gap G can be formed between each end portion. This is to regulate the flow rate of fluid through the bypass flow path 220 according to the movement of the pair of valve blocks 231, 232. The structure and operating state for controlling pressure by operating the pair of valve blocks 231, 232 and regulating the fluid flow rate will be explained again below.

[0056] The elastic member 240 can be disposed between a pair of valve blocks 231, 232 and the piston body 210. In this case, the elastic member 240 is annular so that the piston rod 130 passes through the engagement, and can be formed of rubber material to be elastically deformable.

[0057] Furthermore, although it has been shown and described that the elastic member 240 is made of rubber material, it is not limited thereto. It can be configured in various forms as long as it can elastically support the pair of valve blocks 231, 232 between the pair of valve blocks 231, 232 and the piston body 210. For example, the elastic member 240 can be configured as a disc spring. Figure 5 The figure shows a flow piston valve 200 including an elastic member 240 formed of such a coil spring. The same reference numerals as those shown in the figures of the above embodiments indicate components having the same function. That is, Figure 5 The flow piston valve 200 shown here differs from the embodiment described above only in the type of the elastic member 240, while the other structures are the same. Therefore, detailed descriptions will be omitted.

[0058] Then, refer to Figure 6 and Figure 7 The operating state of the shock absorber 1 having the flow piston valve 200 as described above will be explained.

[0059] Figures 6 to 8 These are diagrams illustrating the operating states of the flow piston valve when the shock absorber is in its extension stroke according to an embodiment of the present invention.

[0060] First, refer to Figure 1 and Figure 6As the vehicle vibrates during travel, the piston valve 140 moves towards the extension chamber 120 along with the piston rod 130 during the extension stroke of the shock absorber 1. At this time, the fluid in the extension chamber 120 flows towards the compression chamber 110 through the flow path formed in the piston valve 140, generating a damping force. Simultaneously, the fluid in the upper chamber 121 flows towards the lower chamber 122 through the bypass flow path 220 formed in the flow piston valve 200 without encountering significant resistance.

[0061] Next, refer to Figure 7 As the piston rod 130 moves further towards the guide rod 150, the limiter 160 partially presses against the flow piston valve 200 from below and raises it, thereby increasing the pressure in the upper chamber 121. Specifically, the limiter 160 moves upward, causing the flow piston valve 200 to move upward, thus moving a pair of valve blocks 231, 232 towards the piston body 210. At this time, the lower valve block 232, supported by the limiter 160, moves to contact the elastic member 240 located at the lower part of the piston body 210, while the upper valve block 231, supported by the guide rod 150, contacts the elastic member 240 located at the upper part of the piston body 210. Therefore, the distance between the pair of valve blocks 231, 232 and the piston body 210 narrows, thereby reducing the fluid flow rate.

[0062] Then, refer to Figure 8 As the piston rod 130 moves further towards the guide rod 150, the upper valve block 231 and lower valve block 232, under pressure from the limiter 160, cause the elastic member 240 to elastically deform and move to contact the piston body 210. Therefore, the distance between the pair of valve blocks 231, 232 and the piston body 210 decreases, thereby further reducing the flow rate of fluid through the bypass path 220. Consequently, the damping force generated by fluid resistance will further increase.

[0063] Furthermore, even if a pair of valve blocks 231, 232 are in contact with the inclined surfaces 213 of the second main body portion 212 formed on the upper and lower parts of the piston body 210, fluid can flow because the outer end of the first flow path 221 is exposed to the gap G of the upper chamber 121 compared to the outer diameter of the pair of valve blocks 231, 232.

[0064] When the piston rod 130 is in the opposite compression stroke after the extension stroke, the piston rod 130 descends, and the limiter 160 and the flow piston valve 200 will... Figure 1 The separated states shown in the diagram decrease together. At this time, the damping force is generated only through the piston valve 140.

[0065] The limiter 160 and the flow piston valve 200 rise in contact with each other when the piston rod 130 is in the extension stroke. Furthermore, the damping force generated by the flow piston valve 200 during the extension stroke is generated when a pair of valve blocks 231, 232 are pressed against the piston body 210, thus reducing contact noise and lowering manufacturing costs through a simple structure.

[0066] Furthermore, although a shock absorber 1 according to one embodiment of the present invention is shown and described as regulating the flow rate of fluid through the bypass flow path 220 by providing a flow piston valve 200 and adjusting the flow rate of fluid through the limiter 160 and guide rod 150 according to the extension stroke of the piston rod 130, it is not limited thereto. The shock absorber 1 can be configured to combine various structures to regulate the flow rate of the bypass flow path 220. For example, the shock absorber 1 according to the present invention may further include damping devices 310, 320, 330 for reducing contact impact on the flow piston valve 200. Figures 9 to 11 Shock absorbers 1 having such damping devices 310, 320, and 330 are shown. Reference numerals identical to those shown in the accompanying drawings of the above embodiments indicate components having the same function.

[0067] According to this embodiment, damping devices 310, 320, and 330 can be disposed on the upper part of the flow piston valve 200. Figure 9 In this context, the damping device 310 can be configured as a spring. Figure 10 In this context, the damping device 320 can be configured as a rubber damper. Figure 11 In this process, the damping device 330 can be configured as a separate flow piston valve. These damping devices 310, 320, and 330 can be applied to the shock absorber 1 according to an embodiment of the present invention. During the extension stroke, the limiter 160 is pressed against the flow piston valve 200 from below and raised to move a pair of valve blocks 231 and 232 toward the piston body 210, thereby adjusting the flow area of ​​the oil through the bypass flow path 220.

[0068] As described above, although the present invention has been illustrated by way of limited embodiments and drawings, the present invention is not limited thereto. Those skilled in the art to which this invention pertains can make various modifications and variations within the equivalent scope of the technical concept of the present invention and the claims.

Claims

1. A shock absorber, comprising: Cylinder, filled with fluid; A piston valve is installed inside the cylinder on a reciprocating piston rod, dividing the space inside the cylinder into an extension chamber and a compression chamber. A guide rod is disposed at the upper part of the cylinder to guide the movement of the piston rod; A limiter, coupled to the outside of the piston rod; and A flow piston valve, connected by the piston rod, divides the expansion chamber into an upper chamber and a lower chamber, and provides multiple bypass flow paths to connect the upper and lower chambers. Specifically, when the piston rod is in its extension stroke, the limiter partially presses against the flow piston valve from below and raises it, thereby regulating the flow rate of the fluid through the bypass path. The flow piston valve includes a piston body and a pair of valve blocks. The piston body includes: an annular first body portion disposed on the piston rod; and a second body portion extending upward and downward from the first body portion and contacting the inner surface of the cylinder. The upper and lower parts of the second main body are configured as tapered shapes, with the diameter of the inner side gradually decreasing towards the first main body. The pair of valve blocks are configured to have a tapered shape so as to contact the inner surface surfaces of the upper and lower parts of the second main body, respectively.

2. The shock absorber according to claim 1, wherein, The piston body is connected by the piston rod, and the bypass flow path is formed on the inner side. The pair of valve blocks are passed through by the piston rod and are spaced apart from the upper and lower parts of the piston body by a predetermined distance. The flow piston valve further includes: An elastic member is disposed between the piston body and the pair of valve blocks. The pair of valve blocks cause the elastic member to elastically deform and move toward the piston body.

3. The shock absorber according to claim 1, wherein, The bypass flow route passes through the second main body and is formed by a groove on the inner surface of the second main body in the vertical direction.

4. The shock absorber according to claim 1, wherein, The bypass path includes: A first flow path is formed on the conical inclined surface of the second main body; and The second flow path is connected to the first flow path and has a greater depth than the first flow path.

5. The shock absorber according to claim 4, wherein, The outer diameter of the pair of valve blocks is set to be located inside the outer end of the first flow path formed in the second body.

6. The shock absorber according to claim 2, wherein, The elastic member is formed of elastically deformable rubber material or a spring.

7. The shock absorber according to claim 1, further comprising: A damping device is provided at the upper part of the flow piston valve to reduce the contact impact of the flow piston valve when the piston rod is in the extension stroke.

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