KR20160060548A

KR20160060548A - shock absorber

Info

Publication number: KR20160060548A
Application number: KR1020150153094A
Authority: KR
Inventors: 진일찬; 김선희
Original assignee: 진일찬; 김선희
Priority date: 2014-11-20
Filing date: 2015-11-02
Publication date: 2016-05-30

Abstract

Disclosed is a shock absorber placed in between two members which can relatively move. In an embodiment of this invention, the shock absorber comprises: a first cylinder; a second cylinder; a free piston; a buffer material; a first valve member; and liquid. The first cylinder has an open end. The second cylinder has an open end connected to the first cylinder through the one end of the first cylinder, and can move relatively to the first cylinder by coming in contact with the internal surface or external surface of the first cylinder. The free piston is placed in the first cylinder to be able to make a sliding displacement along the internal surface of the first cylinder. The buffer material is accommodated in the first cylinder which comes under the space in between the other end of the first cylinder and the free piston. The first valve member is placed in the first cylinder or in the second cylinder which comes under the space between the free piston and the other end of the second cylinder (hereinafter called the first operating space). The liquid is inserted into the first operating space. The free piston conveys the pressure change of the liquid and the pressure change of the buffer material in accordance with the movement of the second cylinder relative to the first cylinder. The first valve member generates a damping force by the flow of the liquid generated by the movement of the second cylinder relative to the first cylinder. The present invention provides a shock absorber which employs a first cylinder and a second cylinder, which can relatively move, to have strong points on the load in a horizontal direction, to have no limit in the stroke distance, and to prevent cavitation.

Description

Shock absorber

TECHNICAL FIELD [0002] The art disclosed in this specification relates to a shock absorber, and more particularly, to a shock absorber using a first cylinder and a second cylinder in which a liquid and a cushioning material are embedded therein and which are movable relative to each other.

Suspension is also referred to as a suspension device, which means a vehicle, such as an automobile, that reaches the supporting device of the vehicle. Suspension consists of a shock absorber, also called a spring and a damper, or a shock absorber. In general, the spring determines the stroke of the suspension, and the shock absorber determines its travel speed. The biggest factor determining the degree of softness and hardness of the suspension is the spring constant, which acts to convert the vibration energy of the spring into thermal energy to generate the damping force.

The prior art of the shock absorber is generally a mono-tube type as shown in FIG. 1, and a piston rod (hereinafter referred to as a rod) is connected to a vehicle body, and a cylinder portion It is connected to the axle (wheel). Of course, they may be connected to each other in reverse, but in this case, there is a disadvantage that the center of gravity is located on the upper part due to the load of the cylinder part.

The interior of the cylinder consists of a liquid chamber filled with an incompressible liquid (e.g. oil) and a gas chamber filled with a compressible fluid (e.g. nitrogen or air), and a free piston is used to isolate the liquid and gas chambers. Respectively. The gas chamber is provided in most shock absorbers to suppress the cavitation phenomenon.

Piston valves generate the flow resistance of the liquid during the compression phase (bump) and the expansion phase (rebound) of the shock absorber and generate a damping force by using this. Depending on the stroke of the rod, the volume of the liquid chamber interior increases and decreases by the load-carrying volume (the shaded portion in Fig. 1). Since the liquid is incompressible, the compressible fluid (e.g., gas) is increased and decreased by this volume. In other words, the gas chamber functions to compensate for the increase or decrease of the liquid pressure depending on the volume of the load flowing into the liquid chamber. Due to this function of the gas chamber, the gas pressure inside the gas chamber is required to some extent to suppress the cavitation phenomenon of the liquid. That is, the gas chamber plays a role of volume compensation according to the compression phase and the expansion phase and suppression of the cavitation phenomenon of the liquid. In addition, due to the limited volume of the gas chamber, the gas chamber performs a buffering function such as a spring in the compression phase and the expansion phase.

In the case of the conventional monotube type shock absorber, when the gas pressure is high, it is difficult to maintain the inner airtightness, and the frictional resistance of the guide portion in contact with the inner surface of the cylinder becomes large.

Further, in the case of the conventional monotube type shock absorber, there is a dilemma depending on the thickness of the rod entering and exiting the cylinder. More specifically, if the thickness of the rod is narrowed, more liquid can be injected into the liquid chamber, so that the amount of liquid flowing through the piston valve increases and the performance of the shock absorber is improved. However, And is susceptible to a load in the lateral direction. Conversely, if the thickness of the rod is made thick, the lateral load applied to the shock absorber has a strength, but the amount of the liquid that can be injected into the liquid chamber is reduced according to the thickness of the rod. This may lead to deterioration in performance such as stain resistance and high temperature resistance of the liquid. Further, the volume of the rod pushed into the cylinder during the compression phase becomes relatively large, and the amount of gas shrinkage of the gas chamber increases. In this process, the gas chamber becomes relatively high pressure, which makes it difficult to maintain the internal airtightness and may cause performance deterioration of the shock absorber due to heat generation.

In addition, in the conventional monotube type shock absorber, since the gas chamber is disposed inside the cylinder, there is a problem that the stroke distance of the rod is limited.

The shock absorber disclosed in this specification adopts the first cylinder and the second cylinder capable of moving relative to each other and has a buffer material therein to reduce the restriction on the stroke distance and has a strength against the lateral load, It is different from the conventional art in that it can prevent the problem.

Prior art related to the shock absorber includes Korean Patent Laid-Open Publication No. 10-1998-056927 entitled " Gas-enclosed shock absorber " and Korean Patent No. KR 10-0311864 " Suspension device ".

The shock absorber disclosed in the present specification adopts a first cylinder and a second cylinder capable of relative movement with respect to each other, A shock absorber capable of preventing a cavitation phenomenon and having a strength, a stroke distance is not limited, and the like.

In one embodiment, a shock absorber disposed between two relatively movable members is disclosed. The shock absorber includes a first cylinder, a second cylinder, a free piston, a buffer material, a first valve member, and a liquid. The first cylinder has an open end. The second cylinder has an open end communicating with the first cylinder through the one end of the first cylinder and is movable relative to the first cylinder while being in close contact with the inner surface or the outer surface of the first cylinder Do. The free piston is disposed inside the first cylinder and is slidably disposed along the inner wall of the first cylinder. The cushioning material is accommodated in the first cylinder corresponding to the space between the other end of the first cylinder and the free piston. The first valve member is disposed inside the first cylinder or inside the second cylinder corresponding to a space between the free piston and the other end of the second cylinder, hereinafter referred to as a first operating space. The liquid is sealed in the first operation space. The free piston transmits a pressure change of the liquid and a pressure change of the cushioning material in accordance with the relative movement of the second cylinder with respect to the first cylinder. The first valve member generates a damping force by the flow of the liquid generated by the relative movement of the second cylinder with respect to the first cylinder.

The cushioning material may include at least one selected from an elastic body having one end connected to the free piston and the other end connected to the first cylinder, a gas having a predetermined pressure, and a combination thereof.

Wherein the damping force of the first valve member when the relative movement of the second cylinder with respect to the first cylinder has a compression phase is determined when the relative movement of the second cylinder with respect to the first cylinder has an expansion phase The first valve member may have a different value from the damping force of the first valve member.

Wherein the first valve member comprises a first disc member which is fitted in the first operating space and which defines the first operating space, and a second disc member which is formed in the first disc member and which, in the relative movement of the second cylinder with respect to the first cylinder, A first valve and a second valve for opening and closing the first flow path and the second flow path through which the liquid flows, and the first flow path and the second flow path, respectively. Wherein the first valve opens the first flow path in the compressed phase phase and the second valve opens the second flow path in the case of the expansion phase and the cross sectional area of the first flow path is different from the cross sectional area of the second flow path Value so that the damping force of the first valve member in the compression phase and the damping force of the first valve member in the expansion phase may have different values.

A second valve member disposed inside the first cylinder or inside the second cylinder corresponding to a space between the free piston and the first valve member, hereinafter referred to as a second operation space; And a rod connected to the second valve member and extending out of the first cylinder. Wherein the first cylinder is connected to one of the two members via the rod and the second valve member is connected to the inside or the outside of the first cylinder in the relative movement of the second cylinder with respect to the first cylinder, Wherein the first valve member is capable of sliding displacement along the inner wall surface of the second cylinder and the second valve member generates an additional damping force by the flow of the liquid produced by the relative movement of the second cylinder with respect to the first cylinder .

Wherein the additional damping force of the second valve member when the relative movement of the second cylinder with respect to the first cylinder has a compression phase is such that the relative movement of the second cylinder with respect to the first cylinder has an expansion phase The second valve member may have a different value from the additional damping force of the second valve member.

Wherein the second valve member comprises a second disc member which is fitted in the second operating space and which defines the second operating space, a second disc member formed on the second disc member, and in the relative movement process of the second cylinder with respect to the first cylinder, And a third valve and a fourth valve that respectively open and close the third and fourth flow paths in which the liquid flows, and the third flow path and the fourth flow path, respectively. The third valve opens the third flow path in the compressed phase phase, the fourth valve opens the fourth flow path in the case of the expansion phase, and the cross sectional area of the third flow path is different from the cross sectional area of the fourth flow path Value so that the additional damping force of the second valve member at the compression phase and the additional damping force of the second valve member at the expansion phase may have different values.

The shock absorber disclosed in this specification can increase the capacity of the liquid as compared with the conventional shock absorber of the same length by employing the first cylinder and the second cylinder capable of moving relative to each other. This makes it possible to provide a stable damping force.

Further, since the shock absorber disclosed in the present specification adopts the first cylinder and the second cylinder which can move relative to each other, the rod used in the conventional shock absorber can be replaced with a cylinder or supplemented with a cylinder, Can be provided.

Also, unlike a conventional gas-type shock absorber using only gas, the shock absorber disclosed in this specification can use at least one selected from an elastic body, a gas, and a combination thereof as a buffer material. This makes it possible to overcome the difficulty of maintaining the airtightness at the high gas pressure of the conventional gas-type shock absorber.

In addition, the shock absorber disclosed in this specification can minimize the space between the external spring and the cylinder, which is inevitably generated in the conventional rod type shock absorber structure, and can utilize this space as a part of the gas chamber or the liquid chamber, have. Thereby providing an advantage of increasing the stroke distance of the shock absorber.

The foregoing provides only a selective concept in a simplified form as to what is described in more detail hereinafter. The present disclosure is not intended to limit the scope of the claims or limit the scope of essential features or essential features of the claims.

Fig. 1 is a view for explaining the operation of the compression phase and the expansion phase of the conventional shock absorber of the monotube system constituted by the rod and the cylinder and the conventional shock absorber.
2 is a diagram illustrating one embodiment of a shock absorber disclosed herein.
3 is a diagram illustrating another embodiment of the shock absorber disclosed herein.
4 is a view for explaining the structure of a valve member which can be adopted in the first valve member and the second valve member of the shock absorber disclosed in this specification.

Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the drawings. Like reference numerals in the drawings denote like elements, unless the context clearly indicates otherwise. The exemplary embodiments described above in the detailed description, the drawings, and the claims are not intended to be limiting, and other embodiments may be utilized, and other variations are possible without departing from the spirit or scope of the disclosed technology. Those skilled in the art will appreciate that the components of the present disclosure, that is, the components generally described herein and illustrated in the figures, may be arranged, arranged, combined, or arranged in a variety of different configurations, all of which are expressly contemplated, As shown in FIG. In the drawings, the width, length, thickness or shape of an element, etc. may be exaggerated in order to clearly illustrate the various layers (or films), regions and shapes. When a component is referred to as being " deployed "to another component, it may include the case where the component is directly disposed on the other component, as well as the case where additional components are interposed therebetween.

When one component is referred to as being "disposed" to another component, it may include the case where the one component is disposed directly on the other component, as well as the case where additional components are interposed therebetween.

When one component is referred to as "connecting to another component ", it includes not only the case where the one component is directly connected to the other component, but also a case where an additional component is interposed therebetween.

The description of the disclosed technique is merely an example for structural or functional explanation and the scope of the disclosed technology should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the rights of the disclosed technology should be understood to include equivalents capable of realizing the technical ideas.

It is to be understood that the singular " include " or "have" are to be construed as including the stated feature, number, step, operation, It is to be understood that the combination is intended to specify that it is present and not to preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

Unless defined otherwise, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed technology belongs. Terms defined in commonly used dictionaries should be interpreted to be consistent with meaning in the context of the relevant art and can not be construed as having ideal or overly formal meaning unless expressly defined in the present application.

Hereinafter, the structure and operation of the shock absorber disclosed in this specification will be described with reference to the accompanying drawings.

Fig. 1 is a view for explaining the operation of the compression phase and the expansion phase of the conventional shock absorber of the monotube system constituted by the rod and the cylinder and the conventional shock absorber. Fig. 1 (a) is a view before the operation, (b) is a view in a compression phase, and Fig. 1 (c) is a view in an expansion phase. 2 is a diagram illustrating one embodiment of a shock absorber disclosed herein. Fig. 2 (a) shows a state before the operation, (b) shows a state in a compressed phase, and Fig. 2 (c) shows a state in an expanded phase. 3 is a diagram illustrating another embodiment of the shock absorber disclosed herein. Fig. 3 (a) is a view before the operation, (b) is a view in a compression phase, and Fig. 3 (c) is a view in an expansion phase. 4 is a view for explaining the structure of a valve member which can be adopted in the first valve member and the second valve member of the shock absorber disclosed in this specification. Fig. 4 (a) is a top view of the valve member, Fig. 4 (b) is a cross-sectional view with reference to line AA ' Sectional view.

First, the operation of the conventional monotube type shock absorber will be described with reference to FIG. 1, a conventional monotube type shock absorber 10 includes an outer spring 11, a cylinder 12, a rod 13, a rod stopper 13a, a free piston 14, an upper closure 15, A valve member 16, a rod fixing portion 17, and an external spring supporting portion 18. The valve member 16, the rod fixing portion 17, The valve member 16 operates when the rod 13 moves according to an external force applied to two relatively movable members (not shown) to which the shock absorber 10 is connected. The two relatively movable members may be, for example, a vehicle body and a vehicle body, respectively. In this case, the cylinder 12 and the rod 13 of the shock absorber 10 may be connected to the vehicle body and the axle, respectively, directly or via other components, or may be reversed from each other and connected to the axle and the vehicle body. The valve member 16 is provided with a plurality of flow paths through which the liquid contained in the liquid chamber in the cylinder 12 can move as the valve member 16 moves in the liquid chamber. The liquid may be, for example, oil. Some of the plurality of flow paths may be opened in the compression phase of the shock absorber 10 and the other part of the plurality of flow paths may be opened in the expansion phase of the shock absorber 10. [ By adjusting the cross-sectional area of the portion and the other portion of the plurality of flow paths, the shock absorber 10 can provide different damping forces in the compression phase and the expansion phase.

The conventional shock absorber 10 has a single cylinder 12 structure in which the liquid and the gas are separated through the free piston 14 disposed therein, and the pressure of the liquid increases in the compression phase as in Fig. 1 (b) , And the free piston (14) compresses the gas to compensate it. That is, when the rod 13 is introduced into the cylinder 12, that is, inside the liquid in the compressed phase, the pressure of the liquid is increased by the volume of the introduced rod 13 and the liquid generally exhibits the non- The free piston 14 compresses the gas to compensate for the increased pressure. The gas chamber compression volume 19 shows the volume of gas compressed according to the volume of the loaded rod 13.

The conventional shock absorber 10 causes an increase in the gas chamber compression volume 19 when the length of the stroke of the rod 13 is increased or the diameter of the rod 13 is increased in order to increase the lateral stiffness. As a result, the gas chamber becomes relatively high in pressure, which makes it difficult to maintain the internal airtightness and may cause deterioration of the shock absorber performance due to heat generation. In addition, since the conventional shock absorber 10 has the gas chamber disposed inside the cylinder 12, there is a problem that the stroke distance of the rod 13 is restricted.

The shock absorber disclosed in the present specification can increase the capacity of the liquid when compared with a conventional shock absorber of the same volume by adopting the first cylinder and the second cylinder capable of moving relative to each other. This makes it possible to provide a stable damping force. In addition, the shock absorber disclosed in this specification can replace the rod used in the conventional shock absorber with a cylinder having a large cross-sectional area by adopting the first cylinder and the second cylinder capable of moving relative to each other or supplementing the rod with the cylinder having a large cross- It is possible to provide a shock absorber having a characteristic of being resistant to lateral load. Also, unlike a conventional gas-type shock absorber using only gas, the shock absorber disclosed in this specification can use at least one selected from an elastic body, a gas, and a combination thereof as a buffer material. This makes it possible to overcome the difficulty of maintaining the airtightness at the high gas pressure of the conventional gas-type shock absorber. In addition, the shock absorber disclosed in this specification can minimize the space between the external spring and the cylinder, which is inevitably generated in the conventional rod type shock absorber structure, and can utilize this space as a part of the gas chamber or the liquid chamber, have. Thereby providing an advantage of increasing the stroke distance of the shock absorber.

Hereinafter, the structure and operation of the shock absorber 100, 100a disclosed in this specification will be described with reference to Figs. 2 to 4. Fig.

Referring to Figure 2, one embodiment of a shock absorber disposed between two relatively movable members disclosed herein will be described. The two relatively movable members may be, for example, a vehicle body and a vehicle body, respectively. In this case, the first cylinder 120a and the second cylinder 120b of the shock absorber 100 may be connected to the vehicle body and the axle, respectively, directly or via other components, or may be reversed in position with respect to the axle and the vehicle body Can be connected. In addition, the first cylinder 120a and the rod 130 of the shock absorber 100a may be connected to the vehicle body and the axle, respectively, via direct or other components, or may be reversed from each other to be connected to the axle and the vehicle body . It will be appreciated that the above example is for illustrative purposes and that the shock absorber disclosed herein can be used in a variety of mechanisms where impact reduction is desired.

The shock absorber 100 includes a first cylinder 120a, a second cylinder 120b, a free piston 140, a shock absorber 142, a first valve member 160a, and a liquid (not shown).

The first cylinder 120a has an open end.

The second cylinder 120b has an open end that communicates with the first cylinder 120a through the one end of the first cylinder 120a and has a first end connected to the first cylinder 120a, Relative movement with respect to the cylinder 120a is possible. 2 shows a first cylinder 120a as a first cylinder 120a which moves relative to the inner surface of the second cylinder 120b while being in close contact with the inner surface of the second cylinder 120b. Alternatively, unlike the drawings, the first cylinder 120a may move relative to the outer surface of the second cylinder 120b while being in close contact with the outer surface of the second cylinder 120b.

The free piston 140 is disposed inside the first cylinder 120a and is disposed slidably along the inner wall of the first cylinder 120a.

The buffer material 142 is accommodated in the first cylinder 120a corresponding to the space between the other end of the first cylinder 120a and the free piston 140. [ In one embodiment, the cushioning material 142 may include at least one selected from an elastic body having one end connected to the free piston 140 and the other end connected to the first cylinder 120a, a gas having a predetermined pressure, . &Lt; / RTI > In the drawing, a buffer material 142 constituted by an elastic body having the shape of a coil spring is shown as an example of the buffer material 142. [ Alternatively, unlike the one shown in the drawings, a gas having a predetermined pressure may be used as the buffer material 142, and an elastic body having a shape of a coil spring and a gas having a predetermined pressure may be used at the same time. It is preferable to use an elastic body as the buffering material 142. In this case, by using an elastic body as the buffering material 142, it is difficult to maintain the internal airtightness due to the high pressure that may occur when using a gas, The performance degradation can be prevented.

The first valve member 160a is disposed inside the first cylinder 120a corresponding to the space between the free piston 140 and the other end of the second cylinder 120b 120b. The first operating space is filled with a liquid (e.g., oil). In the figure, the first valve member 160a, the first valve member 160a disposed at the one end of the first cylinder 120a and the inside of the second cylinder 120b belonging to the first operating space, . In this case, the first valve member 160a may be fixedly disposed at the one end of the first cylinder 120a. Alternatively, as shown in the drawings, the first valve member 160a may be fixedly disposed inside the first cylinder 120a belonging to the first operating space, or may be fixedly disposed inside the second cylinder 120b .

In this case, the free piston 140 performs a function of transferring the pressure change of the liquid and the pressure change of the damping material 142 due to the relative movement of the second cylinder 120b with respect to the first cylinder 120a . In other words, when the first cylinder 120a is introduced into the liquid in the relative movement of the second cylinder 120b with respect to the first cylinder 120a, the volume of the liquid flowing in the first cylinder 120a The free piston 140 compresses the buffer chamber to compensate for the increased pressure of the liquid. In this process, the free piston 140 is retracted. The buffer chamber compression volume 190 shows the volume of the buffered portion compressed according to the volume of the introduced cylinder.

The first valve member 160a generates a damping force by the flow of the liquid generated by the relative movement of the second cylinder 120b with respect to the first cylinder 120a. In one embodiment, the damping force of the first valve member 160a when the relative movement of the second cylinder 120b with respect to the first cylinder 120a has a compression phase, And may have a different value from the damping force of the first valve member 160a when the relative movement of the second cylinder 120b has an expansion phase.

For example, the first valve member 160a may include a first disc member 162a fitted in the first operating space and defining the first operating space, a first disc member 162a formed in the first disc member 162a, The first flow path 164a and the second flow path 164b and the first flow path 164a and the second flow path 164b in which the liquid flows in the relative movement of the second cylinder 120b with respect to the second cylinder 120b And may include a first valve 166a and a second valve 166b. The first valve 166a opens the first flow path 164a in the compression phase and the second valve 166b opens the second flow path 164b in the expansion phase and the cross sectional area of the first flow path 164a The valve channel and the lift of the second flow path 164b have different values so that the damping force of the first valve member 160a in the compression phase and the damping force of the first valve member 160a in the expansion phase They can have different values.

More specifically, by adjusting at least one of the length, the cross-sectional area, and the combination thereof of the flow path of the first flow path 164a and the second flow path 164b, the shock absorber 100 is different in the compression phase and the expansion phase Damping force can be provided. Alternatively, by adjusting the degree of opening and closing of the valve that opens and closes the first flow path 164a and the second flow path 164b, the shock absorber 100 can provide different damping forces in the compression phase and the expansion phase. The adjustment of the first flow path 164a and the second flow path 164b and the adjustment of the valve may be performed simultaneously or separately. For example, the valves can be constructed of laminated leaf springs, and the degree of lift of the leaf spring according to the flow of the liquid can be adjusted by varying the spring constant of the leaf spring, Different damping forces can be provided in the phase and the expansion phase.

4 shows a valve member 160 in which the sectional area of the first flow path 164a is larger than the sectional area of the second flow path 164b as an example of the valve member 160 applicable to the first valve member 160a, . In this case, the first valve member 160a can provide a low damping force in the compression phase and a large damping force in the expansion phase. Alternatively, the damping force may be adjusted by varying the lengths of the first flow path 164a and the second flow path 164b, as shown in FIG. Further, in the figure, a leaf spring-shaped structure laminated as the first valve 166a and the second valve 166b is shown as an example. In this case, by varying the degree of overlap between the stacked leaf springs applied to the first valve 166a and the second valve 166b, or by varying the spring constant of the leaf spring, It is possible to control the amount of the liquid passing through the liquid passage 164b. Whereby the damping force of the shock absorber 100 disclosed in this specification can be controlled. For example, the first valve 166a and the second valve 166b may be configured to restrict the amount of liquid passing through the first flow path 164a and the second flow path 164b, There is no.

Referring to Fig. 3, another embodiment of a shock absorber disposed between two relatively movable members disclosed in this specification will be described. The two relatively movable members may be, for example, a vehicle body and a vehicle body, respectively. It will be appreciated that the above example is for illustrative purposes and that the shock absorber disclosed herein can be used in a variety of mechanisms where impact reduction is desired.

The shock absorber 100a includes a first cylinder 120a, a second cylinder 120b, a free piston 140, a cushioning material 142, a first valve member 160a, a liquid (not shown), a second valve member 160b and a rod 130.

The second valve member 160b is disposed inside the first cylinder 120a corresponding to the space between the free piston 140 and the first valve member 160a and hereinafter referred to as the second operating space or the second cylinder 120b ). &Lt; / RTI >

The rod 130 is connected to the second valve member 160b and may extend outside the first cylinder 120a.

The first cylinder 120a may be connected to one of the two members through a rod 130. [ The second valve member 160b is located in the inside of the first cylinder 120a or the inside wall of the second cylinder 120b in the relative movement of the second cylinder 120b with respect to the first cylinder 120a The sliding displacement is possible. The second valve member 160b can generate additional damping force by the flow of the liquid generated by the relative movement of the second cylinder 120b with respect to the first cylinder 120a.

In one embodiment, the additional damping force of the second valve member 160b when the relative movement of the second cylinder 120b relative to the first cylinder 120a has a compressive phase, is applied to the first cylinder 120a And may have a different value from the additional damping force of the second valve member 160b when the relative movement of the second cylinder 120b for the second cylinder 120b has an expansion phase. Hereinafter, the second valve member 160b will be described using the valve member 160 shown as an example in Fig.

For example, the second valve member 160b may include a second disc member 162b fitted in the second operating space and defining the second operating space, a second disc member 162b formed in the second disc member 162b, The third flow path 164a and the fourth flow path 164b and the third flow path 164a and the fourth flow path 164b through which the liquid flows in the relative movement of the second cylinder 120b with respect to the second cylinder 120b And may include a third valve 166a and a fourth valve 166b. The third valve 166a opens the third flow path 164a in the compression phase and the fourth valve 166b opens the fourth flow path 164b in the expansion phase and the cross sectional area of the third flow path 164a Has a different value from the cross sectional area of the fourth flow path (164b) so that the additional damping force of the second valve member (160b) in the compression phase and the additional damping force of the second valve member (160b) It can have different values. The operation and configuration of the second valve member 160b are substantially the same as the operation and configuration of the first valve member 160a, and a detailed description thereof will be omitted for the sake of convenience.

Referring to Figure 3, the operation of another embodiment 100a of a shock absorber disposed between two relatively movable members disclosed herein will be described again.

The shock absorber 100a includes a first valve member 160a and a second valve member 160b. The shock absorber 100a is disposed between the two members in which the rod 130 and the second cylinder 120b are movable relative to each other. That is, the relative movement of the two members is transmitted to the rod 130 and the second cylinder 120b, so that the rod 130 and the second cylinder 120b may have a compressed phase or an expanded phase. During the compression phase process, the second valve member 160b is moved toward the second cylinder 120b. In this process, the liquid is moved through the second valve member 160b to generate the damping force. At this time, the first cylinder 120a, which is in contact with the inner surface of the second valve member 160b, also moves toward the second cylinder 120b by friction with the second valve member 160b. In this process, The liquid is moved through the valve body 160a to generate a damping force. This operation occurs in substantially the same way in the expansion phase process.

In other words, the shock absorber 100a described above with reference to FIG. 3 differs from the shock absorber 100 described with reference to FIG. 2 in that the damper 100a differs from the flow of the liquid passing through the first valve member 160a and the second valve member 160b, . Through this, the shock absorber 100a disclosed in this specification can provide a greater design freedom to the user of the shock absorber.

On the other hand, the shock absorbers 100 and 100a disclosed in the present specification provide the effect of increasing the amount of flow through the valve member compared to the conventional monotube type shock absorber 10 of the same size, 160a, and 160b can be increased in design freedom and damping force sensitivity. 1, the flow rate of the liquid passing through the valve member 16 in the case of the compressed phase is substantially the same as that of the rod 13 Corresponds to a value obtained by subtracting the gas chamber compression volume 19 from the volume corresponding to the length L_rod. 2, in the case of the compression phase, the flow rate of the liquid passing through the first valve member 160a is smaller than the flow rate of the liquid flowing into the liquid chamber, Corresponds to a value obtained by adding the buffer chamber compression volume 190 to the volume corresponding to the length (L_cylinder) of the first cylinder 120a. This is a natural result as the liquid passes through the first valve member 160a to compress the buffer chamber. 3, the flow rate of the liquid that affects the damping force of the shock absorber 100a according to another embodiment depends on the length L_cylinder of the first cylinder 120a flowing into the liquid chamber in the compressed phase, The volume corresponding to the length L_rod of the rod 13 flowing into the liquid chamber, and the buffer chamber compression volume 190. The flow rate of these liquids flows through the first valve member 160a and the second valve member 160b, and a damping force is generated in this process. The flow of the fluid in the case of the expansion phase can be sufficiently deduced in the above-described process with respect to the case of the compression phase, so that a detailed description thereof will be omitted for the sake of explanation.

As described above in detail with respect to Figs. 2 to 4, the shock absorbers 100 and 100a disclosed in the present specification employ a first cylinder and a second cylinder capable of moving relative to each other, The capacity of the liquid can be increased. This makes it possible to provide a stable damping force. In addition, the shock absorbers 100 and 100a disclosed in the present specification employ a first cylinder and a second cylinder capable of moving relative to each other, thereby replacing a rod used in a conventional shock absorber with a cylinder having a large sectional area, It is possible to provide a shock absorber which can be complemented by a wide cylinder and has a characteristic of being resistant to lateral load. The shock absorbers 100 and 100a disclosed in this specification can use at least one selected from an elastic body, a gas, and a combination thereof as a shock absorber, unlike a conventional gas shock absorber using only gas. This makes it possible to overcome the difficulty of maintaining the airtightness at the high gas pressure of the conventional gas-type shock absorber. In addition, the shock absorbers 100 and 100a disclosed in this specification can minimize the space between the external spring and the cylinder, which necessarily occurs in the conventional rod type shock absorber structure, and utilize this space as a part of the gas chamber or the liquid chamber It is possible to increase the degree of freedom. Thereby providing an advantage of increasing the stroke distance of the shock absorber.

From the foregoing it will be appreciated that various embodiments of the present disclosure have been described for purposes of illustration and that there are many possible variations without departing from the scope and spirit of this disclosure. And that the various embodiments disclosed are not to be construed as limiting the scope of the disclosed subject matter, but true ideas and scope will be set forth in the following claims.

L_rod: Load travel distance
L_cylinder: Cylinder relative moving distance
10: Conventional monotube type shock absorber
11: External spring
12: Cylinder
13: Load
13a: Load stopper
14: Free piston
15: Upper closure
16: valve member
17:
18: outer spring support
19: Gas chamber compression volume
100, 100a: shock absorber
110: outer spring
120a: first cylinder
120b: second cylinder
130: Load
130a: Road stopper
140: Free piston
142: Cushioning material
160: valve member
160a: a first valve member
160b: a second valve member
162: disc member
162a: first disc member
162b: second disk member
164a: first and third channels
164b: the second flow passage, the fourth flow passage
166a: first valve, third valve
166b: a second valve, a fourth valve
170: first cylinder fixing portion
170a:
190: buffer chamber compression volume

Claims

A shock absorber disposed between two relatively movable members,
The shock absorber
A first cylinder having an open end;
A second cylinder having an open end communicating with the first cylinder through the one end of the first cylinder and capable of relative movement with respect to the first cylinder in close contact with an inner or outer surface of the first cylinder;
A free piston disposed slidably along an inner wall of the first cylinder inside the first cylinder;
A damping member accommodated in the first cylinder corresponding to a space between the other end of the first cylinder and the free piston;
A first valve member disposed inside the first cylinder or inside the second cylinder corresponding to a space between the free piston and the other end of the second cylinder, hereinafter referred to as a first operation space; And
And a liquid contained in the first operation space,
Wherein the free piston transmits a pressure change of the liquid and a pressure change of the buffer according to the relative movement of the second cylinder with respect to the first cylinder,
Wherein the first valve member generates a damping force by the flow of the liquid produced by the relative movement of the second cylinder relative to the first cylinder.

The method according to claim 1,
Wherein the cushioning material includes at least one selected from an elastic body having one end connected to the free piston and the other end connected to the first cylinder, a gas having a predetermined pressure, and a combination thereof.

3. The method according to claim 1 or 2,
Wherein the damping force of the first valve member when the relative movement of the second cylinder with respect to the first cylinder has a compression phase is determined when the relative movement of the second cylinder with respect to the first cylinder has an expansion phase Wherein the second valve member has a different value from the damping force of the first valve member.

The method of claim 3,
The first valve member
A first disc member interposed in the first operation space to partition the first operation space;
A first flow path formed in the first disk member and through which the liquid flows in the relative movement of the second cylinder with respect to the first cylinder; And
A first valve and a second valve for opening and closing the first flow path and the second flow path, respectively,
Wherein the first valve opens the first flow path in the compressed phase phase and the second valve opens the second flow path in the case of the expansion phase and the cross sectional area of the first flow path is different from the cross sectional area of the second flow path Value so that the damping force of the first valve member in the compression phase and the damping force of the first valve member in the expansion phase differ from each other.

3. The method according to claim 1 or 2,
A second valve member disposed inside the first cylinder or inside the second cylinder corresponding to a space between the free piston and the first valve member, hereinafter referred to as a second operation space; And
And a rod connected to the second valve member and extending out of the first cylinder,
Wherein the first cylinder is connected to one of the two members via the rod,
The second valve member is slidable along the inner wall of the first cylinder or the inner wall of the second cylinder in the relative movement of the second cylinder with respect to the first cylinder,
Wherein the second valve member generates an additional damping force by the flow of liquid generated by the relative movement of the second cylinder relative to the first cylinder.

6. The method of claim 5,
Wherein the additional damping force of the second valve member when the relative movement of the second cylinder with respect to the first cylinder has a compression phase is such that the relative movement of the second cylinder with respect to the first cylinder has an expansion phase Wherein the second valve member has a different value from the additional damping force of the second valve member.

The method according to claim 6,
The second valve member
A second disk member interposed in the second operation space to partition the second operation space;
A third passage and a fourth passage formed in the second disk member, through which the liquid flows in the relative movement of the second cylinder with respect to the first cylinder; And
A third valve and a fourth valve for opening and closing the third flow path and the fourth flow path, respectively,
The third valve opens the third flow path in the compressed phase phase, the fourth valve opens the fourth flow path in the case of the expansion phase, and the cross sectional area of the third flow path is different from the cross sectional area of the fourth flow path Value so that the additional damping force of the second valve member at the compression phase and the additional damping force of the second valve member at the expansion phase have different values.