JP2008064223A - Damping valve structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve intended damping characteristics without requiring drastic design change nor using a large number of components with respect to existing products. <P>SOLUTION: This damping valve structure comprises holes 5a for working fluid passage opposing to an upstream side end of an extension side port 3a opened on a valve seat member 3 capable of communicating an upstream side with a downstream side defined by the valve seat member 3 with each other; and a retraction side valve 5 for closing a downstream side end of a retraction side port 3b opened on the valve seat member 3 to open/close the retraction side port 3b. In the back pressure face side of the retraction side valve 5, a conical spring 10 for making a space between windings serve as a clearance S for working fluid passage is opposingly arranged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a damping valve structure, and more particularly to an improvement of a damping valve structure suitable for implementation in a hydraulic shock absorber constituting a suspension device in a vehicle such as an automobile.

  There have been various proposals for a damping valve structure suitable for realizing a hydraulic shock absorber constituting a suspension device of a vehicle such as an automobile. Among them, for example, Patent Document 1 discloses a predetermined damping structure. A damping valve structure is disclosed that is capable of generating a force.

  That is, in the damping valve structure disclosed in Patent Document 1, the piston as the valve seat member in the piston portion of the storage shock absorber has the expansion side port in the cylinder of the hydraulic shock absorber, and the downstream end of the expansion side port can be opened and closed. It has an extension side damping valve that is closed at the end.

  In this damping valve structure, the extension side damping valve is formed by stacking three or more annular leaf valves, and each of the plurality of annular leaf valves has a flow path having a different planar shape. A notch is formed.

  Therefore, in this damping valve structure, it is possible to devise the flow path of the hydraulic oil by laminating the plurality of annular leaf valves. Therefore, in particular, the piston speed is from a very low speed range to a low speed range. It is possible to generate the damping force when it is in the desired manner.

According to this damping valve structure, this can be further evolved, or a bypass path that bypasses the extension-side damping valve is provided and a valve that can further select a so-called on / off operation is provided in the bypass path. Thus, it can be said that the damping force can be controlled when the piston speed is in the middle speed range or the high speed range.
JP 2006-177469 (Abstract, see FIGS. 1 to 4)

  However, although the proposal itself disclosed in Patent Document 1 does not have a particular problem, it is pointed out that, as an extension of this proposal, even if it is further evolved, control of damping force cannot be realized in a preferable form. There is a possibility.

  That is, the damping force generated by the damping valve structure in the hydraulic shock absorber constituting the suspension device of a vehicle such as an automobile can be regarded as a so-called piston speed starting from a very low speed range to a low speed range to a medium speed range. Some are suitable for control when the normal speed range is set, and some are suitable for control when the piston speed is set in a so-called high speed range where the piston speed is in a high speed range.

  In the damping valve structure proposed so far, basically, one of the normal speed range and the high speed range is often prioritized. In other words, there were few cases that were said to be suitable for both.

  In other words, as described above, it can be said that it is not impossible to provide a damping valve structure that is suitable for both when the damping valve itself and its surroundings are variously devised, as described above. .

  However, in realizing the damping valve structure that is suitable for both the normal speed range and the high speed range, generally, there is a concern that the number of parts, processing man-hours, and assembly man-hours will increase. As a result, it is feared that the product cost of the hydraulic shock absorber is likely to increase.

  The present invention has been developed in view of the above-described present situation, and the object of the present invention is to achieve a desired attenuation without requiring a significant design change or the use of a large number of parts with respect to an existing one. It is an object of the present invention to provide a damping valve structure that can embody characteristics and can be expected to improve versatility of a hydraulic shock absorber that constitutes a suspension device in a vehicle such as an automobile.

  In order to achieve the above object, the structure of the damping valve structure according to the present invention basically includes a valve seat member that defines an upstream side and a downstream side, and an upstream side that is opened in the valve seat member. Extension port and pressure side port that allow communication between the extension side port, the extension side damping valve that closes the downstream side end of the extension side port so that it can be opened and closed, and the hydraulic oil passage that faces the upstream side end of the extension side port In a damping valve structure having a pressure side valve composed of an annular leaf valve that is fixed at the inner peripheral end and is closed at the downstream end of the pressure side port so that the downstream end can be opened and closed. It is assumed that a conical spring is disposed on the pressure side so as to face the gap between the windings for passage of hydraulic oil.

  Therefore, in the present invention, the hydraulic oil from the upstream side flows out to the downstream side, for example, through the hydraulic oil passage hole, the expansion side port, and the expansion side damping valve opened in the pressure side valve. If the piston speed is in the so-called normal speed range from low speed to medium speed, the conical spring is not crushed by the hydraulic action from the upstream side, and the hydraulic oil passage hole of the pressure side valve is formed. A so-called fully open state is maintained, and a set damping force is generated by the expansion side damping valve.

  On the other hand, when the hydraulic oil from the upstream side flows out to the downstream side through the hydraulic oil passage hole, the expansion side port and the expansion side damping valve that are opened in the pressure side valve, the piston speed becomes high so-called high speed If it is in the region, the conical spring is crushed by the hydraulic action from the upstream side, and the gap between the windings is reduced to suppress the amount of hydraulic oil passing through the hydraulic oil passage hole of the pressure side valve. Therefore, the damping force at this time is combined with the damping force by the expansion side damping valve to generate a so-called high damping force.

  As a result, according to the present invention, when the piston speed is shifted from the so-called normal speed range to the so-called high speed range only by providing the conical spring without changing the configuration of the extension side damping valve and the pressure side valve, the extension is performed. The above-described high damping force can be achieved by the side damping valve, and a desired damping characteristic can be realized without requiring a significant design change and the use of a large number of parts with respect to the existing one.

  The present invention will be described below on the basis of the illustrated embodiment. The damping valve structure according to the present invention is suitable for implementation in a hydraulic shock absorber constituting a suspension device in a vehicle such as an automobile.

  First, the hydraulic shock absorber will be described. As shown in FIG. 1, the hydraulic shock absorber is held by the tip end portion 2a which is the lower end portion of the piston rod 2 inserted in the cylinder 1 so as to be able to protrude and retract. The piston 3 is used as a valve seat member according to the present invention, and this valve seat member is used as a valve side member R1 which is an upper chamber in the figure. The piston side chamber R2 that is the lower chamber is defined.

  In this hydraulic shock absorber, the piston 3 as a valve seat member has an expansion side port 3a as an inner port allowing communication between the rod side chamber R1 and the piston side chamber R2, and a pressure side port 3b as an outer port. The downstream end at the lower end in the drawing of the expansion side port 3a is closed so that the expansion side damping valve 4 can be opened and closed, and the downstream end at the upper end in the drawing of the compression side port 3b is opened and closed by the compression side valve 5 It is supposed to be blocked as possible.

  Further, in this hydraulic shock absorber, the extension side damping valve 4 is composed of a laminated annular leaf valve that is fixed at the inner peripheral end and is free from the outer peripheral end. In addition, the valve receiver 41 is adjacent to the back pressure surface, and the annular leaf valve 42 that is fixed at the inner peripheral end and is free from the outer peripheral end is adjacent to the pressure receiving surface that is the upper surface in the drawing.

  At this time, the valve receiver 41 is formed in a structure having a flange portion 41 b at the upper end of the tubular portion 41 a, and the flange portion 41 b is adjacent to the back pressure surface of the outer peripheral portion of the expansion side damping valve 4.

  Further, the annular leaf valve 42 has an orifice 42a formed of a notch on the outer peripheral portion, and the hydraulic oil extending side port from the rod side chamber R1 when the orifice 42a makes the piston speed a very low speed region. The passage to the piston side chamber R2 through 3a is allowed.

  In the valve receiver 41, the upper end of the urging spring 7 having the lower end supported by the piston nut 6 is brought into contact with a so-called rear surface of the flange portion 41b which is the lower surface in FIG. When the flange portion 41b of the valve receiver 41 moves back in the drawing against the spring force of the urging spring 7, the outer peripheral portion is lowered to enter a so-called valve open state.

  On the other hand, in this hydraulic shock absorber, the pressure side valve 5 is composed of an annular leaf valve that is fixed at the inner peripheral end and is free at the outer peripheral end, and has an upper end in the drawing of the above-described extension side port 3a that is lower in the figure. As shown in the figure, an annular leaf valve 51 that is fixed at the inner peripheral end and is free from the outer peripheral end is provided on the pressure receiving surface that is the lower surface in the drawing. It is supposed to be adjacent.

  At this time, the annular leaf valve 51 has a hydraulic oil passage hole 51a communicating with the hydraulic oil passage hole 5a in the pressure side valve 5 and an orifice 51b made of a notch in the outer peripheral portion. The orifice 51b allows passage of hydraulic oil from the piston side chamber R2 to the rod side chamber R1 through the pressure side port 3b when the piston speed is set to a very low speed range.

  Incidentally, the shape of the hydraulic oil passage hole 51a in the annular leaf valve 51 is not shown, but it may be formed in the same circular shape as the hydraulic oil passage hole 5a in the pressure side valve 5, and is also shown in the figure. However, it may be formed in an arc shape.

  Further, regarding the orifice 51b formed in the annular leaf valve 51, in consideration of the function of the orifice 51b, instead of forming the orifice 51b, the valve 3 is stamped on the valve seat surface of the piston 3 serving as a valve seat member. An orifice may be formed, and when the stamping orifice is formed, the annular leaf valve 51 can be omitted.

  As shown in the figure, when the annular leaf valve 51 is laminated on the pressure side valve 5, it is advantageous in that it can be expected to improve durability against bending in the pressure side valve 5 which is also formed of an annular leaf valve.

  In the drawing, the pressure side valve 5 is a so-called damping valve. However, from the point of view of the present invention, the pressure side valve 5 does not need to be a damping valve, and the annular leaf valve 51 is provided. Needless to say, the suction valve may be configured by only the compression side valve 5 without being stacked.

  Further, regarding the upstream side and the downstream side defined by the valve seat member which is the piston 3, in the illustrated hydraulic shock absorber, the rod side chamber R1 or the piston side chamber R2 defined by the piston 3 is provided in the cylinder 1. Accordingly, when the piston 3 moves up in the cylinder 1, the rod side chamber R1 is on the upstream side, and when the piston 3 moves down in the cylinder 1, the piston side chamber R2 is on the upstream side.

  Therefore, when the arrangement of the conical spring 10 to be described later is not taken into account, in this hydraulic shock absorber, when the piston 3 moves up in the cylinder 1, the hydraulic oil from the rod side chamber R1 on the upstream side is discharged. The pressure side valve 5 flows through the hole 5a, the hole 51a of the annular leaf valve 51, the expansion side port 3a, and the expansion side damping valve 4 into the piston side chamber R2, where the expansion side damping valve 4 operates at this time. Thus, an extension side damping force having a predetermined magnitude is generated.

  Further, the arrangement of the conical spring 10 which will be described later will be exaggerated. In this hydraulic shock absorber, when the piston 3 moves down in the cylinder 1, the hydraulic oil from the piston side chamber R2 on the upstream side is not. The pressure side port 3b and the pressure side valve 5 will flow out to the rod side chamber R1, and the pressure side damping force of a predetermined magnitude will be generated by the operation of the pressure side valve 5 at this time.

  By the way, the above description refers to the case where the piston speed in the cylinder 1 is in the low speed range to the medium speed range, and the case where the piston speed is in the high speed range will be described later. In some cases, a predetermined damping force is generated by the hydraulic oil passing through the orifices 42a and 51b formed in the annular leaf valves 42 and 51 stacked on the expansion side damping valve and the pressure side valve, respectively. become.

  In contrast to the above, when the piston speed is in the high speed range, in the present invention, a predetermined damping force is generated by the operation of the conical spring 10.

  Therefore, the conical spring 10 and the place where the conical spring 10 operates will be described below. First, the conical spring 10 is illustrated in FIG. 1 of the compression side valve 5 as shown in FIG. In the state of being arranged on the back pressure surface side which is the upper surface side, as shown in FIG.

  Then, this conical spring 10 is shown in FIG. 3 by the hydraulic action from the rod side chamber R1, which is the upstream side, when the piston 3 is in the extending operation in which the piston 3 moves up in the cylinder 1 and the piston speed is in the high speed range. At this time, the gap S is narrowed to suppress the flow rate of the hydraulic oil in the hydraulic oil passage hole 5a opened in the pressure side valve 5.

  For this reason, the conical spring 10 is set so as to exhibit a function different from that of a non-return spring that is arranged when this type of pressure side valve 5 is set as a so-called suction valve.

  That is, first, it is assumed that the winding is made thick so that it can be easily subjected to a hydraulic action, and then the gap S between the windings is made as narrow as possible so that the resistance when hydraulic fluid passes therethrough. It is easy to become.

  Further, as shown in the figure, even if this kind of conical spring 10 is crushed, there is a tendency to increase the outer diameter. It is assumed that the size of the gap S is easily controlled.

  That is, in the illustrated case, it is assumed that the spring seat member 11 is disposed between the conical spring 10 and the compression side valve 5, and the spring seat member 11 has a plurality of planar shapes as shown in FIG. The main body 11a is formed so as to have a so-called human hand shape having a radial shape.

  The conical spring 10 includes a restricting portion 11b that rises at the tip of the main body portion 11a. The restricting portion 11b increases the outer diameter of the conical spring 10 when it is crushed. The diameter is said to be blocked.

  Therefore, in this conical spring 10, when the hydraulic fluid from the rod side chamber R1 on the upstream side where the piston speed is in the high speed range flows toward the piston side chamber R2 on the downstream side, that is, the rod When the hydraulic oil from the side chamber R1 flows out into the piston side chamber R2 through the hole 5a of the pressure side valve 5, the expansion side port 3a and the expansion side damping valve 4, the hydraulic action because the piston speed is in the high speed range. As a result, the conical spring 10 is crushed, and at this time, the gap S between the windings is narrowed.

  As a result, the pressure side valve 5 has a high damping force by which the opening area of the hydraulic oil passage hole 5a, that is, the flow rate of the hydraulic oil passing through the hydraulic oil passage hole 5a is suppressed. Will occur.

  Therefore, in the pressure side valve 5 in which the conical spring 10 formed as described above is disposed opposite to the so-called upstream side that is the upper side in FIG. 1, the so-called normal speed range in which the piston speed is from low speed to medium speed. The hydraulic oil from the upstream rod chamber R1 is discharged to the downstream side piston side chamber R2 through the hydraulic side passage hole 5a, the expansion side port 3a and the expansion side damping valve 4 which are opened in the pressure side valve 5. When this happens, the conical spring 10 is not crushed, and the hydraulic oil passage hole 5a of the compression side valve 5 is maintained in a so-called fully open state, and a set damping force is generated in the expansion side damping valve 4. Will be.

  On the other hand, the hydraulic oil from the rod side chamber whose piston speed is in the high speed region is downstream through the hydraulic oil passage hole 5a, the extension side port 3a and the extension side damping valve 4 which are opened in the pressure side valve 5. When the conical spring 10 flows into the piston side chamber R2, the conical spring 10 is seated on the pressure side valve 5 by the hydraulic action from the rod side chamber R1, and the amount of hydraulic oil passing through the hydraulic oil passage hole 5a of the pressure side valve 5 is suppressed. Therefore, the damping force at this time is combined with the damping force set by the expansion side damping valve 4 to generate a so-called high damping force.

  As a result, according to the present invention, the piston speed is shifted from the so-called normal speed range to the so-called high speed range only by providing the conical spring 10 without changing the configuration of the expansion side damping valve 4 and the pressure side valve 5. In addition, the above-described high damping force can be achieved by the expansion side damping valve 4, and desired damping characteristics can be realized without requiring a significant design change and the use of a large number of parts with respect to the existing one. .

  In view of the above, it is preferable that the conical spring 10 in the present invention is made of a synthetic resin material, as compared to the case where the spring such as a coil spring is formed of a steel wire in many cases. .

  When the conical spring 10 is made of a synthetic resin material, it is advantageous in that the weight is reduced as compared with the case where the conical spring 10 is formed of a steel wire, and it is advantageous in that the product cost can be reduced. I will.

It is a fragmentary longitudinal cross-sectional view which shows partially the hydraulic shock absorber which embodied the damping valve structure by this invention in the piston part in a cylinder. It is a top view of the conical spring seen from the XX line position of FIG. It is a fragmentary sectional view which expands and shows the operating state of the conical spring in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston rod 3 Piston which is a valve seat member 3a Extension side port 3b Pressure side port 5 Pressure side valve 10 Conical spring 11 Spring seat member 11b Control part 51 Annular leaf valve 51b Orifice R1 Rod side chamber R2 Piston side chamber S Gap

Claims (5)

A valve seat member that defines an upstream side and a downstream side; an extension port and a pressure side port that are opened in the valve seat member to allow communication between the upstream side and the downstream side; and a downstream end of the extension side port With an expansion side damping valve that can be opened and closed, and an inner peripheral end fixed that can open and close the downstream side end of the compression side port while having a hydraulic fluid passage hole facing the upstream side end of the expansion side port In a damping valve structure having a pressure side valve made up of an annular leaf valve that is free to end, a conical spring that makes a gap between the windings for passing hydraulic oil is disposed opposite to the back pressure surface side of the pressure side valve. Damping valve structure characterized by The damping valve structure according to claim 1, wherein a spring seat member having a restricting portion that prevents the outer diameter of the conical spring from expanding is disposed between the conical spring and the pressure side valve. The damping valve structure according to claim 1, wherein the conical spring is made of a synthetic resin material. The damping according to claim 1, wherein the pressure side valve is formed by laminating an annular leaf valve having a notch orifice on the outer peripheral portion and closing the downstream end of the pressure side port so as to be openable and closable while the inner peripheral end is fixed and the outer peripheral end is free. Valve structure. The valve seat member is slidable in a state where the valve seat member is held by the piston rod in the cylinder in the hydraulic shock absorber, and is the piston in the piston portion of the storage, the upstream side is the rod side chamber defined by the piston in the cylinder, and the downstream The damping valve structure according to claim 1, wherein the side is a piston side chamber defined by a piston in a cylinder.

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