KR20200142839A - Shock absorber - Google Patents

Abstract

A shock absorber is disclosed. The shock absorber includes: a cylinder in which an inner tube and an outer tube are provided to fill fluid; a piston valve that divides the inner tube into a tension chamber and a compression chamber; and a piston rod that is connected to the piston valve and is extended to the outside of the inner tube. The shock absorber includes: a piston unit that moves up and down along the inner circumferential surface of the inner tube and has a penetrated center unit; an elastic member provided to be elastically deformed according to the movement of the piston unit; and a guide unit fixed to the inner circumferential surface of the inner tube to support the elastic member, wherein the piston valve is provided to press the piston unit and the elastic member during a compression stroke, and the piston unit has a flow path extended radially outward from the center on the upper surface.

Description

Shock absorber {SHOCK ABSORBER}

The present invention relates to a shock absorber that generates an additional damping force during a compression stroke.

In general, a shock absorber serves to suppress or attenuate vibration from a road surface, and absorbs vibration energy in the vertical direction of the vehicle body when mounted between a vehicle body or a frame and a wheel. Among such shapes of the shock absorber, the abdominal type shock absorber includes a cylinder provided with an inner tube and an outer tube, and a piston rod slidably accommodated in the inner tube, and the cylinder is connected to the wheel side through a suspension arm, etc. The piston rod is connected to the vehicle body side, and a piston valve is connected to the lower end of the piston rod.

Accordingly, the shock absorber can perform a function of suppressing and attenuating the vibration transmitted from the road surface to the vehicle body while continuously repeatedly performing a compression stroke and a rebound stroke when the vehicle travels on an irregular road surface. . Here, the piston valve allows the fluid to move in one direction by the pressing force of the disk, and the disk is opened or closed with respect to the flow path due to a pressure difference between the tension chamber and the compression chamber due to the expansion or contraction of the shock absorber. As the disk is tilted by the flow rate passing through the slit of the disk, a general damping force may be generated.

On the other hand, in order to obtain additional damping force during the compression stroke, a separate housing having an orifice hole was conventionally installed inside the inner tube. More specifically, the piston rod descending to a certain height or less during the compression stroke is introduced into the above-described housing to form a chamber. Subsequently, when the additional compression stroke proceeds, the fluid in the chamber is discharged through the orifice hole, thereby generating additional damping force. However, if the housing is placed inside the inner tube as in the prior art, noise may be generated by contact between the piston rod and the metal material of the housing during the descending process, and damage to the piston rod and the housing may occur. There is a problem. In addition, since the piston rod and the above-described housing must be coaxially arranged and assembled, there is a problem that the assembly cost or parts management cost may be excessively consumed in the production process.

Korean Patent Publication No. 2006-0102691 (published on September 28, 2006)

The present embodiment is to provide a shock absorber capable of stably generating an additional damping force during a compression stroke.

The present embodiment is to provide a shock absorber capable of minimizing noise generation.

The present embodiment is to provide a shock absorber with improved performance and operational reliability.

The present embodiment is intended to provide a shock absorber capable of improving product assembly and productivity while reducing the manufacturing cost of the product.

According to an aspect of the present invention, a cylinder in which an inner tube and an outer tube are provided to be filled with fluid, a piston valve that divides the inner tube into a tension chamber and a compression chamber, and a piston valve connected to the piston valve to the outside of the inner tube. In the shock absorber comprising a piston rod extending to the inner circumferential surface of the inner tube, a piston part that moves up and down along the inner circumferential surface of the inner tube and penetrates the center thereof, an elastic member provided to be elastically deformed according to the movement of the piston part, and fixed to the inner circumferential surface of the inner tube And a guide portion supporting the elastic member, wherein the piston valve is provided to pressurize the piston portion and the elastic member during a compression stroke, and the piston portion includes a flow path portion extending radially outward from the center portion on an upper surface thereof. Can be provided.

The compression chamber includes a first chamber located above the piston part and a second chamber located below the piston part, wherein the piston part is provided to pressurize the fluid in the second chamber during a compression stroke, and the flow path The unit may be provided and provided to allow the flow of the pressurized fluid in the second chamber.

The flow path portion may be provided and provided to have a uniform width and depth.

The flow path portion may be provided so as to increase the depth toward the outer side in the radial direction of the piston portion.

The passage portion may be provided so as to have a wider width toward the outer side in the radial direction of the piston portion.

One side of the elastic member may be elastically supported by the piston and the other side may be elastically supported by the guide unit.

The piston may further include a groove formed along an outer circumferential surface, and an external O-ring inserted into the groove to seal a gap between the inner circumferential surface of the inner tube and the piston.

It may further include a fixing portion disposed under the guide portion and provided to fix the guide portion with respect to the inner circumferential surface of the inner tube.

The shock absorber according to the present embodiment may stably provide additional damping force during a compression stroke.

The shock absorber according to the present embodiment can minimize the occurrence of noise due to collision between parts.

The shock absorber according to the present embodiment may improve product performance and operational reliability.

The shock absorber according to an embodiment of the present invention can reduce the manufacturing cost of the product while improving the assembly properties and productivity of the product.

1 is a cross-sectional view of a shock absorber according to an embodiment of the present invention.
2 is a cross-sectional view of a piston according to an embodiment of the present invention.
3 is a side cross-sectional view of a piston part according to an embodiment of the present invention.
4 is a cross-sectional view of a piston according to another embodiment of the present invention.
5 is a cross-sectional view taken along line A-A' of FIG. 4.
6 is a cross-sectional view of a piston part according to another embodiment of the present invention.
7 is a diagram showing a process in which a general damping force is generated during a compression stroke of a shock absorber according to an embodiment of the present invention.
8 is a diagram illustrating a process in which a damping force is generated during an additional compression stroke after the compression stroke of FIG. 7.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following examples are presented in order to sufficiently convey the spirit of the present invention to those of ordinary skill in the art to which the present invention pertains. The present invention is not limited to the exemplary embodiments presented here, but may be embodied in other forms. In the drawings, in order to clarify the invention, the illustration of parts irrelevant to the description may be omitted, and the size of the component may be slightly exaggerated to help understanding.

1 is a cross-sectional view of a shock absorber according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a piston part according to an embodiment of the present invention, and FIG. 3 is a side cross-sectional view of a piston part according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view of a piston part according to another embodiment of the present invention, FIG. 5 is a cross-sectional view taken along line A-A' of FIG. 4, and FIG. 6 is a cross-sectional view of a piston part according to another embodiment of the present invention.

1, a shock absorber 1 according to an embodiment of the present invention includes an inner tube 2 filled with a fluid, an outer tube 3 provided around the outer circumference of the inner tube 2 and filled with a fluid. , The inner tube 2 is installed to be slid up and down in the inner tube 2 to separate the inner tube 2 into a tension chamber 13 and a compression chamber 14, and the piston valve 4 A piston rod 5 connected to the outside of the inner tube 2 and a body valve 6 installed below the inner tube 2 are included. In addition, the shock absorber 1 according to the embodiment of the present invention elastically supports the piston part 20 that moves up and down along the inner circumferential surface of the inner tube 2 and the piston part 20 from the lower part of the piston part 20 And a guide portion 23 fixed to support the elastic member 22 under the elastic member 22 and the elastic member 22.

The piston valve 4 includes a compression passage 11 and a tension passage 12 for generating a damping force by allowing a fluid flow according to a compression stroke and a tension stroke. Similarly, the body valve 6 includes a communication passage 15 for generating a damping force by allowing the flow of fluid according to the tension stroke and the compression stroke. The piston valve 4 divides the inner tube 2 into a tension chamber 13 and a compression chamber 14. During the compression stroke, the fluid filled in the compression chamber 14 flows upward along the compression flow path 11, and the fluid filled in the tension chamber 13 during the tension stroke flows downward along the tension flow path 12. Can be.

The piston part 20 is provided to pass through the center portion, for example, the end of the piston rod 5 descending during the compression stroke may enter the above-described center portion. The piston part 20 is provided to divide the compression chamber 14 into an upper first chamber 14a and a lower second chamber 14b. In addition, a flow path part 21 extending radially outward from a center portion through which the piston part 20 is passed may be provided on the upper surface of the piston part 20. As the compression stroke proceeds, pressure is also applied to the fluid in the second chamber 14b disposed under the piston part 20, and the fluid in the pressurized second chamber 14b flows along the flow path part 21. It can be fluid.

The elastic member 22 is provided so that one side is elastically supported by the piston part 20, and the other side is elastically supported by the guide part 23. That is, since the elastic member 22 can be supported by the guide part 23 fixed to the inner circumferential surface of the inner tube 2, the elastic member 22 will be elastically deformed according to the lifting movement of the piston part 20 contacting the upper end. I can.

The guide part 23 is fixedly provided on the inner circumferential surface of the inner tube 2. According to an embodiment of the present invention, a fixing part 25 is provided that is disposed under the guide part 23 to fix the guide part 23 with respect to the inner circumferential surface of the inner tube 2 and maintain the above-described fixed state. I can.

2 to 6, the flow path part 21a according to an embodiment of the present invention may be provided to have a predetermined width w and a depth h. That is, the hydraulic pressure of the fluid flowing along the flow path part 21a may be uniformly generated. In the flow path part 21b according to another embodiment of the present invention, the depth h'may be provided to become deeper toward the outer side in the radial direction of the piston part 20b. Alternatively, the flow path part 21c according to another embodiment of the present invention may be provided to have a wider width w'toward the outer side in the radial direction of the piston part 20c.

Meanwhile, during the compression stroke, it is necessary to prevent the fluid in the second chamber 14b from being discharged through a flow path other than the flow path part 21. According to an embodiment of the present invention, an external O-ring 24 may be provided to seal the gap between the inner circumferential surface of the inner tube 2 and the piston part 20. In this case, a groove may be formed along the outer circumferential surface of the piston part 20, and the external O-ring 24 may be inserted into the above-described groove and provided to circumscribe the piston part 20.

Hereinafter, an operation of generating a damping force during a compression stroke by the shock absorber 1 according to the present embodiment will be described.

7 is a view showing a process in which a general damping force is generated during a compression stroke of the shock absorber 1 according to an embodiment of the present invention, and FIG. 8 is a diagram illustrating a process of generating a damping force during an additional compression stroke after the compression stroke of FIG. It is a drawing.

Referring to FIG. 7, as the piston valve 4 and the piston rod 5 descend within the inner tube 2 during the compression stroke, the pressure in the compression chamber 14 increases, and a part of the compression chamber 14 The fluid passes through the compressed flow passage 11. At this time, some of the fluid in the compression chamber 14 passes through the compression channel 11 and flows to the upper tension chamber 13, while the remaining fluid is transferred to the outer tube 3 through the communication channel 15. It can generate damping force while moving.

Referring to FIG. 8, as the compression stroke proceeds further, the end of the piston rod 5 enters the center of the piston part 20, and the lower surface of the piston valve 4 makes the upper surface of the piston part 20 Pressurize. One side of the elastic member 22 is elastically supported by the piston part 20, but the other side is elastically supported by the guide part 23, and the guide part 23 is attached to the inner circumferential surface of the inner tube 2 by the fixing part 25. It is fixed. Accordingly, when the piston part 20 is pressed and descends along the inner circumferential surface of the inner tube 2, the elastic member 22 can be compressed while elastically supporting the piston part 20.

When the piston part 20 descends and the elastic member 22 is compressed, the volume of the second chamber 14b decreases, and pressure is applied to the fluid filled therein. In this case, the pressurized fluid passes through the central portion of the piston portion 20 and flows to the flow path portion 21 provided on the upper surface of the piston portion 20, thereby generating additional hydraulic pressure. Thereafter, the fluid that has passed through the flow path part 21 may exist in the first chamber 14a and then again pass through the compression flow path 11 to flow into the tension chamber 13 above. That is, a separate flow path part 21 through which a flow rate can be transmitted to the piston part 20 is formed, and as the number of flow paths allowing the flow of fluid in the compression chamber 14 is added, an additional damping force during the compression stroke Is what can happen.

Referring back to FIGS. 2 and 3, the flow path part 21a according to an embodiment of the present invention may be provided to have a predetermined width w and a depth h. More specifically, as the piston valve 4 presses the piston part 20a and compresses the elastic member 22 during the compression stroke, the flow path part 21a through which the fluid filled in the second chamber 14b passes. ) Width (w) and depth (h) are provided constant. That is, the hydraulic pressure of the fluid for generating an additional damping force may be uniformly generated throughout all stages in which the compression stroke shown in FIG. 8 is generated.

Referring again to FIGS. 4 and 5, the depth h'may be provided to become deeper as it goes outward in the radial direction of the piston part 20b according to another embodiment of the present invention. More specifically, as the piston valve 4 pressurizes the piston part 20b and compresses the elastic member 22 during the compression stroke shown in FIG. 8, the fluid filled in the second chamber 14b has priority. It is provided to pass through the flow path disposed inside in the radial direction. At this time, since the flow path disposed inside the flow path part 21b has a shallower depth h'than the outside, and thus the cross-sectional area of the flow path is formed to be small, the fluid is relatively in the beginning of passing through the flow path part 21b. It can generate strong hydraulic pressure. Thereafter, when the fluid reaches the outside of the flow path part 21b, the depth h'of the flow path becomes deeper and the cross-sectional area becomes large, so that the hydraulic pressure is relatively weaker than in the beginning.

Referring back to FIG. 6, a width w'may be provided to increase radially outward of the piston part 20c according to another embodiment of the present invention. More specifically, since the inside of the flow path part 21c through which the fluid in the second chamber 14b preferentially passes during the compression stroke shown in FIG. 8 forms a flow path having a relatively narrow width and a small cross-sectional area compared to the outside, It can generate strong hydraulic pressure. Thereafter, as the fluid goes to the outside of the flow path part 21c, the width w'of the flow path increases, so that the cross-sectional area of the flow path also increases. That is, the hydraulic pressure generated as the fluid filled in the second chamber 14b flows from the inside to the outside of the flow path part 21c gradually weakens.

As described above, although the present invention has been described by the limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of the present invention and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described.

1: shock absorber 2: inner tube
3: outer tube 4: piston valve
5: piston rod 6: body valve
11: tension passage 12: compression passage
13: tension chamber 14: compression chamber
14a: first chamber 14b: second chamber
15: communication channel 20: piston part
21: flow path 22: elastic member
23: guide part 24: external O-ring
25: fixed part

Claims (8)

A cylinder in which an inner tube and an outer tube are provided to fill a fluid, a piston valve that divides the inner tube into a tension chamber and a compression chamber, and a piston rod connected to the piston valve and extending to the outside of the inner tube. In the shock absorber,
A piston part that moves up and down along the inner circumferential surface of the inner tube and passes through the center thereof;
An elastic member provided to be elastically deformed according to the movement of the piston unit; And
Including; a guide portion fixed to the inner circumferential surface of the inner tube to support the elastic member,
The piston valve
It is provided to pressurize the piston part and the elastic member during the compression stroke,
The piston part
A shock absorber having a flow path extending radially outward from the center on the upper surface. The method of claim 1,
The compression chamber is
A first chamber located above the piston part and a second chamber located below the piston part,
The piston part
It is provided to pressurize the fluid in the second chamber during the compression stroke,
The flow path part
A shock absorber provided to allow the flow of the pressurized fluid in the second chamber. The method of claim 2,
The flow path part
The shock absorber is provided to have a uniform width and depth. The method of claim 2,
The flow path part
The shock absorber is provided to increase the depth toward the outer side in the radial direction of the piston part. The method of claim 2,
The flow path part
A shock absorber provided to have a wider width toward the outer side in the radial direction of the piston part. The method of claim 2,
The elastic member is
A shock absorber whose one side is elastically supported by the piston and the other side is elastically supported by the guide. The method of claim 6,
The piston part
It has a groove formed along the outer peripheral surface,
The shock absorber further comprises an external O-ring inserted into the groove and sealing a gap between the inner circumferential surface of the inner tube and the piston. The method of claim 7,
A shock absorber further comprising a fixing part disposed below the guide part and provided to fix the guide part with respect to the inner circumferential surface of the inner tube.

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