KR101313892B1 - Valve structure of a shock absorber - Google Patents

Abstract

The present invention uses a control valve installed inside the piston rod together with a piston valve installed on the end circumference of the piston rod to divide the inside of the cylinder, thereby reducing the damping force during low speed operation to improve ride comfort. It is about.

According to the present invention, there is a valve structure of a shock absorber that generates a damping force against a pressure of a working fluid, which is provided outside the piston rod of the shock absorber and operates in a state in which the cylinder of the shock absorber is bisected to generate a damping force. A piston valve for letting; A control valve installed inside the piston rod to maintain an open state when the piston rod moves at a low speed and to close when the piston rod moves at a medium speed or a high speed; Provided is a valve structure of a shock absorber, including.

Shock absorber, piston valve, damping force, control valve, pressure sensitive

Description

VALVE STRUCTURE OF A SHOCK ABSORBER}

The present invention relates to a valve structure provided in the pressure-sensitive shock absorber, and more particularly, a control valve installed in the piston rod together with a piston valve installed on the outer periphery of the end of the piston rod to divide the inside of the cylinder. The present invention relates to a shock absorber valve structure that can improve ride comfort by lowering damping force during low speed operation.

Generally, a vehicle is equipped with a shock absorber for improving ride comfort by absorbing shocks or vibrations that the axle receives from the road surface when the vehicle is traveling, and a shock absorber is used as one of such shock absorbers.

The shock absorber operates according to the vibration of the vehicle according to the road surface condition. At this time, depending on the operating speed of the shock absorber, that is, the operating speed is fast or slow, the damping force generated in the shock absorber changes.

The riding comfort and driving stability of the vehicle can be controlled by adjusting the damping force characteristics generated by the shock absorber. Therefore, when designing a vehicle, it is very important to adjust the damping force characteristics of the shock absorber.

Figure 1 shows a prior art shock absorber piston valve. In Fig. 1, the direction of the fluid flow at the time of shock absorber compression is shown on the right side of the center line, and the direction of the fluid flow at the time of shock absorber rebound is shown on the left side of the center line.

The conventional piston valve operates in a state where the inside of the cylinder 10 filled with the working fluid is divided into the first and second chambers 11 and 12 to generate the damping force.

Conventional piston valves coupled to and fixed to the ends of the piston rod 13 by fastening members such as nuts 14 include a plurality of compression paths 15a through which a working fluid passes during compression of the shock absorber; The piston body 15 is provided with a plurality of rebound paths 15b through which the working fluid passes when the shock absorber is extended, and is disposed above the piston body 15 to pass through the compression passage 15a. A first valve means 16 for generating a damping force against the pressure of a working fluid and a damping force against the pressure of the working fluid disposed under the piston body 15 and passing through the rebound passage 15b. And second valve means 17.

As described above, the piston body 15 is provided with a plurality of compression passages 15a and a plurality of rebound passages 15b arranged in a circle. The outer peripheral surface of the piston main body 15 is provided with a band 18 made of Teflon for adhesion with the inner peripheral surface of the cylinder 10 and prevention of abrasion.

The first and second valve means 16 and 17 may be formed of a plurality of disk members, washers, etc., respectively.

As shown on the right side of FIG. 1, when the shock absorber is compressed, that is, when the piston body 15 moves downward in the cylinder, the working fluid is transferred from the second chamber 12 below the piston body 15. It flows through the compression passage 15a and the first valve means 16 to the first chamber 11 above the piston body 15.

On the other hand, as shown in the left side of Fig. 1, when the shock absorber is extended, that is, when the piston body 15 moves upward in the cylinder, the working fluid flows from the first chamber 11 above the piston body 15 Flows sequentially through the first valve means 16, the plurality of rebound passages 15b and the second valve means 17 and flows into the second chamber 12 below the piston body 15.

The first valve means 16 operates to generate a damping force upon compression and to close the compression passage 15a upon rebound. In addition, the second valve means 17 is operative to close the rebound passage 15b formed in the piston body 15 during compression and to generate a damping force upon rebound.

However, in the conventional piston valve as described above, the displacement itself of the shock absorber itself is small at the time of driving the vehicle at a high speed, but has a low-speed damping force characteristic which adversely affects ride comfort due to high frequency characteristics.

In addition, since the conventional piston valve is designed to have a constant damping characteristic at high speed, medium speed, and low speed using a single flow path, if the low speed damping force is lowered to improve the ride quality, There is a fear that this will deteriorate.

Accordingly, it is necessary to continuously research and develop a pressure-sensitive shock absorber capable of improving ride comfort by lowering the low-speed damping force without affecting the medium-speed damping force characteristic.

The present invention for solving these problems, the medium and high speed flow path by using a control valve installed inside the piston rod with a piston valve installed on the end outer periphery of the piston rod to divide the inside of the cylinder It is to provide a valve structure of the pressure-sensitive shock absorber to form a separate to improve the ride comfort by lowering only the low-speed damping force without affecting the high-speed damping force.

According to the present invention for achieving the above object, as a valve structure of the shock absorber for generating a damping force against the pressure of the working fluid, provided on the outside of the piston rod of the shock absorber and divided the inside of the cylinder of the shock absorber A piston valve operating at and generating a damping force; A control valve installed inside the piston rod to maintain an open state when the piston rod moves at a low speed and to close when the piston rod moves at a medium speed or a high speed; Provided is a valve structure of a shock absorber, including.

The control valve may include a rod passage extending in the longitudinal direction in the piston rod, an upper through hole formed in the radial direction of the piston rod and connected to an upper end portion of the rod passage, and an elastic member. It is preferable to include an upper valve body which is pressurized to keep the rod passage open.

At this time, the upper through hole is formed above the piston valve, the first step of closing the rod passage in cooperation with the upper valve body when the piston rod is tensioned at medium or high speed on the inner surface of the rod passage A second stepped portion may be formed in order to seat the other end of the elastic member, one end of which is in contact with the upper valve body.

In addition, the control valve is formed through the radial direction of the piston rod, the upper and lower through-holes connected to the upper and lower portions of the rod passage, respectively, and pressurized to keep the rod passage open by an elastic member It is preferable to include the upper and lower valve bodies.

In this case, the upper through hole is formed above the piston valve and the lower through hole is formed below the piston valve, and the upper valve when the piston rod is tensioned at medium or high speed on the inner surface of the rod passage. A first stepped portion for cooperating with the sieve to close the rod passage, a second stepped portion formed to seat the other end of the elastic member whose one end is in contact with the upper valve body, and the piston rod at medium or high speed A third step part for closing the rod passage in cooperation with the lower valve body and a fourth step part formed to seat the other end of the elastic member having one end in contact with the lower valve body when the pressure is compressed. Can be.

According to the present invention as described above, by using a control valve installed inside the piston rod together with a piston valve which is provided on the end outer periphery of the piston rod to divide the inside of the cylinder, the medium and high speed flow passages are formed separately. A valve structure of one pressure sensitive shock absorber can be provided.

Accordingly, according to the valve structure of the present invention, it is possible to improve the riding comfort by lowering only the low speed damping force without affecting the high speed damping force.

Hereinafter, a valve structure of a pressure sensitive shock absorber according to a preferred embodiment of the present invention will be described in detail with reference to the drawings.

2 and 3 are valve structures of the pressure-sensitive shock absorber according to the first preferred embodiment of the present invention, in which the valve state and fluid flow when the shock absorber is tensioned at a low speed are shown, and FIG. Shows the valve state and fluid flow when the shock absorber is tensioned at high speed.

As shown in FIGS. 2 and 3, the valve structure according to the first embodiment includes two chambers installed inside the cylinder 10, which is installed outside the piston rod 13 and filled with a working fluid such as oil. And a control valve 30 which is installed inside the piston rod 13 and is closed at the high speed tension stroke of the shock absorber. do.

The piston valve 20 coupled to and fixed to the end of the piston rod 13 by a fastening member such as a nut 14 includes a plurality of compression passages 24 and a shock absorber through which a working fluid passes when the shock absorber is compressed. Of the piston body 21 having a plurality of rebound passages 22 through which the working fluid passes, and the pressure of the working fluid disposed above the piston body 21 and passing through the compression passage 24. A first valve means 23 for generating a damping force against and a second valve means 25 for generating a damping force against a pressure of a working fluid disposed under the piston body 21 and passing through the rebound passage 22. ) May be included.

In addition, a band 18 made of Teflon material may be installed on the outer circumferential surface of the piston body 21 to prevent adhesion and wear to the inner circumferential surface of the cylinder 10. The first and second valve means 23, 25 may each consist of a plurality of disc members and washers.

The control valve 30 is formed in the rod passage 31 extending in the longitudinal direction in the piston rod 13 and the radially through the piston rod 13 is connected to the rod passage 31 The upper through hole 32 and the upper valve body 33 pressurized to open the rod passage 31 by an elastic member such as the coil spring 34 are included.

The length of the rod passage 31 is preferably formed longer than the overall thickness of the piston body 21, the first valve means 23 and the second valve means 25, the upper through hole 32 is shown in the figure As shown, it is preferably formed above the piston valve 20. In addition, the upper through hole 32 is preferably formed to communicate with the upper end portion of the rod passage (31).

First and second stepped portions 31a and 31b may be formed on the inner surface of the rod passage 31. As shown in FIG. 3, the first stepped part 31a may close the rod passage 31 in cooperation with the upper valve body 33 when the piston rod 13 is tensioned at medium speed or high speed. The second stepped portion 31b is formed to seat the other end of the coil spring 34 that one end contacts the upper valve body 33 and presses the upper valve body 33 upward in the drawing. Can be.

The upper valve body 33 disposed inside the rod passage 31 and generating a damping force against the pressure of the working fluid is disposed inside the rod passage 31 and has a medium speed or high speed of the shock absorber as described above. The rod passage 31 is closed upon tensioning.

The upper valve body 33 includes a cylindrical portion 33a to which the coil spring 34 is wound around, and a flange portion 33b formed at the upper end of the cylindrical portion 33a, and has a substantially T letter shape. Has a cross-sectional shape of. In design, by changing at least one of the spring constant of the coil spring 34 and the width of the flange portion 33b, the timing at which the control valve 30 is closed (ie, the pressure of the fluid) can be adjusted.

According to the first embodiment of the present invention, since the control valve 30 having the above-described configuration is provided inside the piston rod 13, when the shock absorber is tensioned at low speed, the piston valve 20 and When the fluid flows through the control valve 30 and the shock absorber is tensioned at medium or high speed, the fluid flows only through the piston valve 20. As a result, only the damping force when the shock absorber is tensioned at a low speed can be lowered, thereby improving the riding comfort.

2 and 3, the flow of the fluid during the tension and compression stroke of the shock absorber and the operation of the valve structure according to the first embodiment of the present invention will be described.

In the tension stroke of the shock absorber, the piston valve 20 moves upward in the cylinder 10 together with the piston rod 13. As shown in FIG. 2, when the moving speed of the piston rod is low, the working fluid passes through the rebound passage 22 from the first chamber 11 and then the disk-s 23b of the first valve means 23. Flow toward the second chamber 12 through the slit (23c) formed in the). At the same time, the working fluid flows from the first chamber 11 into the rod passage 31 through the upper through hole 32 and then passes through the gap between the upper valve body 33 and the rod passage 31. Flow toward the second chamber 12.

At this time, since the pressure of the fluid applied to the flange portion 33b of the upper valve body 33 does not compress the coil spring 34, the working fluid may flow through the control valve 30.

As shown in Fig. 3, when the tensioning speed of the piston valve is medium speed or high speed, the working fluid passing through the rebound passage 22 is formed by the disk-s 23b and the plate disk 23a of the first valve means 23. ) Flows toward the second chamber 12 through the space formed by pushing and deforming. On the other hand, as the pressure of the fluid applied to the flange portion 33b of the upper valve body 33 rises, the flange portion 33b of the upper valve body 33 becomes the first stepped portion while compressing the coil spring 34. By contacting 31a), the rod passage 31 is closed. Thus, the working fluid flows only through the rebound passage 22.

In addition, during the compression stroke of the shock absorber, the piston valve moves downward in the cylinder 10, and then the upper valve body 33 does not compress the coil spring 34 regardless of the moving speed of the piston rod. The pressure of the fluid acts so that the control valve 30 remains open.

4 and 5 are valve structures of the pressure-sensitive shock absorber according to the second preferred embodiment of the present invention, in which FIG. 4 shows the valve state and fluid flow when the shock absorber is tensioned at high speed. 5 shows the valve condition and fluid flow when the shock absorber is compressed at high speed.

As shown in FIGS. 4 and 5, the valve structure according to the second embodiment includes two chambers installed inside the cylinder 10, which is installed outside the piston rod 13 and filled with a working fluid such as oil. And a control valve 30 which is installed inside the piston rod 13 and is closed at the high speed tension stroke of the shock absorber. In that, it is the same as that of the valve structure of 1st Embodiment mentioned above.

Since the valve structure according to the second embodiment has a difference from the first embodiment in that the control valve 30 further includes the lower valve element 37, the following description focuses on such differences. In addition, the same member number is attached | subjected to the same member as 1st Embodiment, and detailed description is abbreviate | omitted.

In the second embodiment, the control valve 30 is formed through the rod passage 31 extending in the longitudinal direction inside the piston rod 13 and the rod passage in the radial direction of the piston rod 13. An upper valve body 33 which is pressurized to open the rod passage 31 by an elastic member such as a coil spring 34, an upper through hole 32 and a lower through hole 36 connected to the 31; The lower valve body 37 is included.

As shown in FIGS. 4 and 5, the upper through hole 32 is preferably formed above the piston valve 20, and the lower through hole 36 is preferably formed below the piston valve 20. In addition to the lower through hole 36, the lower end surface of the piston rod 13 is preferably formed with a circular opening 35 in communication with the rod passage 31.

In addition, the upper through hole 32 is preferably formed to communicate with the upper end portion of the rod passage 31, the lower through hole 36 is preferably formed to communicate with the lower end portion of the rod passage 31.

First and second stepped portions 31a and 31b may be formed on an upper inner surface of the rod passage 31, and third and fourth stepped portions 31c and 31d may be formed on a lower inner surface thereof.

As shown in FIG. 4, when the piston rod 13 is tensioned at medium speed or high speed, the first step portion 31a may cooperate with the upper valve body 33 to close the rod passage 31. The second stepped portion 31b is formed to seat the other end of the coil spring 34 that one end contacts the upper valve body 33 and presses the upper valve body 33 upward in the drawing. Can be.

As shown in FIG. 5, when the piston rod 13 is compressed at medium speed or high speed, the third step portion 31c may close the rod passage 31 in cooperation with the lower valve element 37. The fourth stepped portion 31d has one end in contact with the lower valve element 37 so as to seat the other end of another coil spring 38 which presses the lower valve element 37 downward in the drawing. Can be formed.

The upper valve body 33 and the lower valve body 37, which are disposed inside the rod passage 31 and generate a damping force against the pressure of the working fluid, are disposed inside the rod passage 31, as described above. The rod passage 31 is closed during the medium speed or high speed movement (tensile and compression) of the shock absorber.

The upper valve body 33 includes a cylindrical portion 33a to which the coil spring 34 is wound around, and a flange portion 33b formed at the upper end of the cylindrical portion 33a, and has a substantially T letter shape. Has a cross-sectional shape of. In design, by changing at least one of the spring constant of the coil spring 34 and the width of the flange portion 33b of the upper valve body, the timing at which the control valve 30 is closed during tensioning (i.e., the pressure of the fluid) can be adjusted. have.

The lower valve element 37 includes a cylindrical portion 37a to which the coil spring 38 is wound around and a flange portion 37b formed at the lower end of the cylindrical portion 37a, and the letter T is almost inverted. It has a cross-sectional shape of a shape. In the design, by changing at least one of the spring constant of the coil spring 38 and the width of the flange portion 37b of the lower valve body, the timing at which the control valve 30 is closed during compression (i.e., the pressure of the fluid) can be adjusted. have.

According to the second embodiment of the present invention, since the control valve 30 having the above-described configuration is provided inside the piston rod 13, when the shock absorber is tensioned or compressed at a low speed, the piston valve 20 Fluid flows through the piston valve 20 only when the fluid flows through the control valve 30 and the shock absorber is tensioned or compressed at medium or high speed. As a result, only the damping force when the shock absorber moves at low speed can be lowered, thereby improving the riding comfort.

4 and 5, the flow of the fluid during the tension and compression stroke of the shock absorber and the operation of the valve structure according to the second embodiment of the present invention will be described.

In the tension stroke of the shock absorber, the piston valve 20 moves upward in the cylinder 10 together with the piston rod 13. When the moving speed of the piston rod is a low speed, the working fluid passes through the rebound passage 22 from the first chamber 11 and then removes the slit 23c formed in the disk-s 23b of the first valve means 23. Flow through the second chamber 12. At the same time, the working fluid flows from the first chamber 11 into the rod passage 31 through the upper through hole 32, and then the gap between the upper valve body 33 and the rod passage 31, and the lower portion thereof. The gap between the valve element 37 and the rod passage 31 is sequentially passed and flows toward the second chamber 12.

At this time, since the pressure of the fluid applied to the flange portion 33b of the upper valve body 33 does not compress the coil spring 34, the working fluid may flow through the control valve 30.

As shown in FIG. 4, when the tensioning speed of the piston valve is medium speed or high speed, the working fluid passing through the rebound passage 22 is the disk-s 23b and the plate disk 23a of the first valve means 23. ) Flows toward the second chamber 12 through the space formed by pushing and deforming. On the other hand, as the pressure of the fluid applied to the flange portion 33b of the upper valve body 33 rises, the flange portion 33b of the upper valve body 33 becomes the first stepped portion while compressing the coil spring 34. By contacting 31a), the rod passage 31 is closed. Thus, the working fluid flows only through the rebound passage 22.

In addition, the piston valve 20 moves downward in the cylinder 10 with the piston rod 13 at the time of the compression stroke of the shock absorber. When the moving speed of the piston rod is low, the working fluid flows from the second chamber 12 through the compression passage 24 toward the first chamber 11. At the same time, the working fluid flows from the second chamber 12 into the rod passage 31 through the opening 35 and the lower through hole 36, and thereafter, between the lower valve body 37 and the rod passage 31. Flows toward the first chamber 11 sequentially through the gap between and the gap between the upper valve body 33 and the rod passage 31.

At this time, since the pressure of the fluid applied to the flange portion 37b of the lower valve body 37 does not compress the coil spring 38, the working fluid may flow through the control valve 30.

As shown in FIG. 5, when the compression speed of the piston valve is medium or high speed, the working fluid passing through the compression passage 24 is formed through the space formed by pushing and deforming the disk of the second valve means 25. 1 flows to the chamber (11). On the other hand, as the pressure of the fluid applied to the flange portion 37b of the lower valve element 37 increases, the flange portion 37b of the lower valve element 37 moves to the third stepped portion while compressing the coil spring 38. By contacting 31c), the rod passage 31 is closed. Thus, the working fluid only flows through the compression passage 24.

As described above, the piston valve of the shock absorber according to the present invention has been described with reference to the illustrated drawings, but the present invention is not limited to the embodiments and drawings described above, and the present invention belongs to the claims. Of course, various modifications and variations can be made by those skilled in the art.

1 is a side cross-sectional view of a piston valve according to the prior art provided in the shock absorber,

Fig. 2 is a side sectional view of the valve structure according to the first embodiment of the present invention provided in the shock absorber, showing the valve state and fluid flow during a low-speed tension stroke;

3 is a side cross-sectional view of the valve structure according to the first embodiment of the present invention provided in the shock absorber, showing a valve state and fluid flow during a high speed tension stroke;

4 is a side cross-sectional view of the valve structure according to the second embodiment of the present invention provided in the shock absorber, showing a valve state and fluid flow during a high speed tension stroke, and

Fig. 5 is a side sectional view of the valve structure according to the second embodiment of the present invention, which is provided in the shock absorber, and shows a valve state and fluid flow during a high speed compression stroke.

<Explanation of symbols for the main parts of the drawings>

10 cylinder 11 first chamber

12 second chamber 13 piston rod

20: piston valve 21: piston body

22 rebound passage 23 first valve means

24 compression passage 25 second valve means

30 control valve 31 rod passage

31a: first stepped portion 31b: second stepped portion

31c: third step part 31d: fourth step part

32: upper through hole 33: upper valve body

33a, 37a: cylindrical portion 33b, 37b: flange portion

34, 38 coil spring 35 opening

36: lower through hole 37: lower valve body

Claims (5)

A valve structure of a shock absorber that generates a damping force against the pressure of a working fluid, A piston valve (20) provided outside the piston rod (13) of the shock absorber and operating in a state in which the cylinder (10) of the shock absorber is bisected to generate a damping force; A control valve 30 installed inside the piston rod to maintain an open state or close according to a moving speed of the piston rod; / RTI &gt; The control valve may include a rod passage 31 extending in the longitudinal direction of the piston rod, and an upper through hole 32 formed in the radial direction of the piston rod and connected to an upper end portion of the rod passage. And an upper valve body 33 pressurized to maintain the rod passage in an open state by an elastic member, The inner surface of the rod passage has a first step portion 31a for closing the rod passage in cooperation with the upper valve body when the piston rod is tensioned, and one end of the elastic member which is in contact with the upper valve body. The valve structure of the shock absorber, characterized in that the second stepped portion (31b) is formed to seat the other end. The method according to claim 1, The upper through hole is the valve structure of the shock absorber, characterized in that formed above the piston valve. The method according to claim 1, The control valve is formed to penetrate in the radial direction of the piston rod and is pressed by the elastic member 38 to maintain the rod passage in an open state by a lower through hole 36 and a lower portion of the rod passage. A valve structure of a shock absorber comprising a lower valve element (37). The method of claim 3, The lower through hole is a valve structure of the shock absorber, characterized in that formed in the lower portion of the piston valve. The method of claim 3, The inner surface of the rod passage has a third step portion 31c for closing the rod passage in cooperation with the lower valve body when the piston rod is compressed, and one end of the elastic member which is in contact with the lower valve body. A valve structure of a shock absorber, characterized in that a fourth stepped portion (31d) is formed to seat the other end.

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