JP5922948B2 - Shock absorber - Google Patents

Description

  The present invention relates to a shock absorber, and more particularly to an improvement of a hydraulic shock absorber incorporated in a suspension of a vehicle.

  In a hydraulic shock absorber incorporated in a vehicle suspension, for example, it is required to generate a damping force as set in order to obtain a preferable ride comfort in the vehicle.

  For this reason, the hydraulic shock absorber is provided with a damping valve that generates a desired damping force. For example, as shown in FIG. P and a valve V composed of a leaf valve stacked on the piston P.

  The piston P is provided in the cylinder C, and has a seat portion formed at one end and surrounding the opening of the port P1 opened in the piston P, that is, an inner boss portion P2 and an outer seat portion P3. The inner peripheral side end is fixed to the inner boss P2, and the outer peripheral end is seated on the outer sheet P3 and the recess P4 that opens the downstream end of the port P1 is closed openably.

  Therefore, in the above-described hydraulic shock absorber, when the other chamber R2 upstream of the port P1 is on the high pressure side, the hydraulic oil through the port P1 flows from the outer peripheral side end of the valve V and the outer seat portion P3. It passes through the gap that appears between the two and flows out into the one chamber R1 on the downstream side, and the pressure loss at this time causes a damping action.

JP 2010-112464 A

  However, in the hydraulic shock absorber described above, when the hydraulic oil flows out between the outer peripheral side end portion of the valve and the seat portion, abnormal noise is generated or the damping force responsiveness is deteriorated. There is a possibility that it will be pointed out.

  That is, in the place shown in FIG. 4, when the hydraulic oil flows through the gap appearing between the outer peripheral side end portion of the valve V and the outer seat portion P <b> 3 and flows out into the one chamber R <b> 1, it is shown in FIG. 5. Thus, since the gap opens in a so-called lateral direction, the hydraulic oil passing through the gap flows out so as to collide with the cylinder C.

  Therefore, the hydraulic oil that has collided with the cylinder C flows into the one chamber R1 indicated by the solid arrow a in FIG. 5 and flows between the piston P and the cylinder C indicated by the solid arrow b in FIG. It is predicted that the current will be shunted.

  The flow entering between the piston P and the cylinder C does not have a so-called destination, so it is considered that the flow becomes an eddy current and causes abnormal noise generation or a deterioration in damping force responsiveness. Become.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a shock absorber capable of reducing the generation of abnormal noise and the deterioration of damping force responsiveness.

In order to achieve the above-described object, the configuration of the present invention includes a partition body provided in a cylinder, a sheet portion formed at one end of the partition body and surrounding an opening of a port for opening the partition body, In the shock absorber having a valve that is seated on the seat portion and closes the opening of the port so as to be openable, the seat portion is a bulging portion that suppresses the working fluid from flowing between the cylinder and the partition wall body. Is formed on the outer periphery of the seat portion so that the end surface facing the one chamber of the bulging portion is flush with the end surface facing the one chamber of the seat portion up to the outer peripheral surface of the bulging portion. And an outer peripheral surface of the bulging portion is formed flush with an outer peripheral surface of the partition wall, and a direction changing portion protruding outward from one end of the partition wall is formed on the outer peripheral end of the bulging portion. As the inner peripheral surface of the direction changing part goes outward And is the diameter.

  The bulging part provided in the outer periphery of the seat part suppresses the flow of the working fluid flowing out between the outer peripheral side end part of the valve and the seat part into the cylinder and the partition body.

  As a result, it is possible to reduce the occurrence of abnormal noise and the deterioration of the damping force responsiveness due to the working fluid flowing out between the outer peripheral side end portion of the valve and the seat portion flowing between the cylinder and the partition body. It becomes possible.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows one Embodiment of the hydraulic shock absorber by this invention, (A) is a partial semi-longitudinal longitudinal cross-sectional view, (B) is an enlarged view of the part enclosed in the circle in FIG. The enlarged view shows the valve operating. It is a semi-cylindrical end view which shows the one chamber side end surface of a piston. It is a figure which shows other embodiment of a hydraulic shock absorber, (A) is a fragmentary longitudinal cross-sectional view which expands and shows the seat part vicinity, (B) shows the operating state of a valve | bulb. It is a partial half vertical longitudinal cross-sectional view which shows the conventional hydraulic shock absorber. FIG. 6 is a partial semi-longitudinal longitudinal sectional view showing a state where the valve in FIG. 4 is activated.

  Hereinafter, the present invention will be described based on the illustrated embodiment. A shock absorber according to the present invention is, for example, a hydraulic shock absorber incorporated in a suspension of a vehicle, and performs a predetermined damping action during expansion and contraction operation. Suppresses vibrations of the vehicle body and axle.

  The hydraulic shock absorber includes a piston 3 that is a partition wall and a pressure side valve 5 that is a valve stacked on one end that is the upper end of the piston 3 in FIG. In addition, the valve | bulb 4 of the extending | stretching side laminated | stacked on the other end used as the lower end in FIG.

  The piston 3 is formed in an annular shape and is slidably inserted into a cylinder 1 that contains hydraulic fluid as a working fluid, and is held by a tip 2 a of a rod 2 that is inserted into the cylinder 1. One chamber R1 and the other chamber R2 are partitioned inside. The working fluid may be composed of a fluid other than the working oil.

  The piston 3 is fitted with a piston ring 31 as a sliding member on the outer periphery. The outer periphery of the piston ring 31 is in sliding contact with the inner periphery of the cylinder 1 so that the piston 3 can slide with respect to the cylinder 1. Guaranteed.

  Further, the piston ring 31 has an appropriate thickness. Therefore, when the piston ring 31 is fitted on the outer periphery of the piston 3, the piston ring 31 is interposed between the outer periphery of the piston 3 and the inner periphery of the cylinder 1. An interval S that avoids interference appears.

  Returning, the piston 3 has an expansion side port 3a (see FIG. 2) which is alternately formed in the circumferential direction and allows communication between the one chamber R1 and the other chamber R2, and a pressure side port 3b. In FIG. 2 showing one end face of the piston 3, the central portion is a hole (not shown) through which the tip 2 a (see FIG. 1A) of the rod 2 passes.

  The pressure side port 3b opens at the bottom (not shown) of the recess 3c communicating with the other chamber R2 formed at the other end of the piston 3 at the upstream end, which is the lower end in FIG. 1A. In A), the downstream end which is the upper end opens at the bottom (not shown) of the opening window 11 which is a recess formed at one end of the piston 3.

  Although not shown in detail, the port 3a on the extension side opens at the bottom of the opening window formed at the other end of the piston 3 and communicates with the one chamber R1 formed at the one end of the piston 3 at the upstream end. It opens to the bottom (not shown) of the recess 3d (see FIG. 2).

  Therefore, in the hydraulic shock absorber, when the piston 3 moves in the cylinder 1 and the one chamber R1 and the other chamber R2 are widened and narrowed, the hydraulic oil passes through the expansion side port 3a and the pressure side port 3b. And the other chamber R2.

  Returning, the piston 3 has an inner boss portion 12 for fixing the seat portion surrounding the opening which is the downstream end of the pressure side port 3b at one end which is the other chamber R2 side end, that is, the inner boss portion 12 which fixes the inner peripheral side end portion of the pressure side valve 5; And an outer sheet portion 13 for detachably seating an outer peripheral side end portion (not shown) of the pressure side valve 5, and the outer sheet portion 13 is located between the inner boss portion 12 and the opening window. 11 is partitioned.

  As shown in FIG. 2, the opening window 11 is defined by an inner boss portion 12, an outer sheet portion 13, and a connecting portion 14 that connects both of them on both sides. The opening window 11 is separated from the recess 3d that opens the upstream end of the extended port 3a located on both sides in the circumferential direction, and is adjacent to the pressure side port 3b in the circumferential direction of the piston 3. It is supposed that it becomes independent from the other opening window 11 which opens the downstream end of.

  As shown in the figure, the pressure side valve 5 is formed by laminating a plurality of annular leaf valves having the same diameter and a plurality of annular leaf valves having different diameters, and an inner peripheral side end portion is fixed to the boss portion 12. The outer peripheral side end is seated on the outer sheet portion 13 so as to be separable, and the opening window 11 is closed so as to be opened.

  Incidentally, the pressure-side valve 5 is not shown in the figure, but is not shown, but it is not necessary to stack a plurality of annular leaf valves of different diameters because it is composed of a plurality of annular leaf valves of the same diameter. Instead of a plurality of annular leaf valves having a diameter, a single leaf valve may be used.

  Although not shown in detail, the expansion side valve 4 is fixed to the other end of the piston 3 so that the inner peripheral end is fixed and the outer peripheral end is free, and the downstream end of the expansion side port 3a can be opened. Block.

  Further, the pressure side valve 5 and the extension side valve 4 are interposed on the outer periphery of the distal end portion 2a of the rod 2 so as to sandwich the piston 3 from above and below, and the inner peripheral side end portion is the inner boss portion 12, In a state of being seated on 3e, the stepped portion 2b of the rod 2 and the tip thread portion 2c of the rod 2 are clamped between the screwed piston nut 6 and fixed.

  Therefore, in the hydraulic shock absorber, when the piston 3 moves in the cylinder 1 and, for example, the other chamber R2 becomes narrower, the hydraulic oil from the other chamber R2 moves to the outer peripheral side end of the pressure side valve 5. It is bent and passes through the gap that appears between the outer sheet portion 13 and flows out into the one chamber R1, and a predetermined damping action is performed by the pressure loss at this time.

  Contrary to the above, when one chamber R1 is narrowed, the hydraulic oil from one chamber R1 bends the outer end of the valve 4 on the expansion side and flows out into the other chamber R2, and the pressure at this time A predetermined damping action is performed by the loss.

  As described above, in the hydraulic shock absorber, the piston 3 has the pressure-side valve 5 stacked on one end. Therefore, this idea will be described below.

  In other words, in the present invention, the outer sheet portion 13 formed at one end of the piston 3 is provided with a bulging portion 32 on the outer periphery for suppressing hydraulic oil from flowing between the cylinder 1 and the piston 3.

  The bulging portion 32 is formed so that the outer periphery of the outer sheet portion 13 bulges toward the cylinder 1 as shown in the figure. Moreover, as shown in FIG. It is assumed that it is positioned so as to approach the inner periphery of the cylinder 1 with an interval S. In addition, the broken line in FIG. 2 shows the outer periphery of the pressure side valve 5.

  When the bulging portion 32 is formed so as to bulge the outer sheet portion 13 toward the cylinder 1, the bulging portion 32 can be molded together when the piston 3 is molded. become.

  Further, the bulging portion 32 is formed by bulging the outer sheet portion 13 to the outer peripheral side, so that the end surface X (see FIG. 1B) facing the one chamber R1 is the same as that of the outer sheet portion 13. On the other hand, it becomes easy to be flush with the end surface facing the chamber R1, and it is possible to prevent the flow of hydraulic oil flowing between the outer sheet portion 13 and the end surface of the bulging portion 32 from being obstructed. become.

  On the other hand, in the bulging portion 32, the outer peripheral surface Y (see FIG. 1B) facing the cylinder 1 is flush with the outer peripheral surface of the piston 3 in the drawing. As a result, an interval S appearing between the cylinder 1 and the piston 3 also appears between the bulging portion 32 and the cylinder 1.

  As described above, the outer peripheral surface Y of the bulging portion 32 approaches the cylinder 1 with the interval S, so that the hydraulic oil flowing through the end surface X of the bulging portion 32 is between the bulging portion 32 and the cylinder 1. It is suppressed from flowing in and flows into the one chamber R1 as indicated by a solid line arrow in FIG.

  And since the inflow of the hydraulic oil between the bulging part 32 and the cylinder 1 is suppressed, if it is conventional, the flow that enters between the piston and the cylinder becomes a vortex and becomes a cause of noise generation. In comparison with the fact that the damping force responsiveness is deteriorated, the generation of abnormal noise and the deterioration of the damping force responsiveness are suppressed in the hydraulic shock absorber.

  From the above, the piston ring 31 fitted on the outer periphery of the piston 3 is as long as the thickness of the portion protruding from the outer peripheral surface of the piston 3 toward the cylinder 1 is possible, that is, the piston 3 and the cylinder 1 In this case, the hydraulic oil flowing through the end surface of the outer seat portion 13 is suppressed from flowing into the gap S between the cylinder 1 and the piston 3. Will be.

  FIG. 3 shows another embodiment of the bulging portion 32. In this embodiment, the bulging portion 32 protrudes outward from one end of the piston 3 to the outer peripheral side end portion (not shown) which is the right end portion in FIG. The direction change which protrudes toward the one chamber R1 (refer FIG. 1 (A)) in the outer peripheral side end part (not shown) of the end surface X (refer FIG. 1 (B)) of the bulging part 32 which continues to the sheet | seat part 13. A portion 33 is provided.

  In the case of this embodiment, the hydraulic oil flowing through the upper end of the bulging portion 32 is forcibly discharged into the one chamber R1 by the direction changing portion 33 as shown by the solid line arrow in FIG. Thus, the flow between the bulging portion 32 and the cylinder 1 is further effectively suppressed.

  From this, in the case of this embodiment, the inner peripheral surface (not shown) of the direction changing portion 33 is formed so as to increase in diameter toward the upper end of the direction changing portion 33, or the direction changing portion. It is preferable that the connecting portion between the bulging portion 32 and the bulging portion 32 is subjected to a spherical treatment so that the flow of hydraulic oil is smooth.

  In addition, the direction changing portion 33 is integrally formed with the bulging portion 32 in the drawing, but instead of this, for example, as long as mechanical strength is ensured, the bulging portion 33 is not shown. It may be retrofitted to the outer peripheral side end of the protruding portion 32 by using an adhesive or the like.

  And since this direction change part 33 turns the direction of the flow of hydraulic fluid, unless the throttle effect is exhibited, for example, on the end surface X of the bulging part 32 (see FIG. 1B) The outer sheet portion 13 may be provided so as to approach the outer sheet portion 13.

  In the bulging portion 32 formed as described above, the hydraulic oil passes through the gap that appears between the outer peripheral side end portion of the pressure side valve 5 and the outer seat portion 13 and flows out into the one chamber R1. Sometimes, it flows out toward the one chamber R1 along the end surface X of the bulging portion 32.

  And since the bulging part 32 has the direction change part 33 which protrudes toward one chamber R1 in an outer peripheral side edge part, the hydraulic fluid of the flow along the end surface X of the bulging part 32 is forced one side. As a result, the hydraulic oil flows into the chamber R1 and the hydraulic oil is more effectively suppressed from flowing into the space S between the bulging portion 32 and the cylinder 1.

  From the above, the direction changing portion 33 formed in the bulging portion 32 is, as described above, because the outer sheet portion 13 defines the independent opening window 11. That is, it suffices to be provided within a range that is the same as the circumferential length of the outer sheet portion 13.

  On the other hand, although not shown, when the outer sheet portion 13 divides an annular groove as a recess, the above-described direction changing portion 33 has the bulging portion 32 formed on the entire circumference of the outer sheet portion 13. It is preferable that the bulging portion 32 is formed on the entire outer periphery side end portion.

  However, from the viewpoint of the function of the direction changing portion 33, the direction changing portion 33 is not provided on the entire circumference of the bulging portion 32 even when the concave portion is formed of an annular groove, for example, the opening of the port 3b. It is good also as providing only in the outer peripheral side edge part of the bulging part 32 provided in the outer side sheet | seat part 13 which is nearest to (ie, intermittently forming).

  This is because the bulging portion 32 provided on the outer periphery of the outer sheet portion 13 in the present invention is such that the outer peripheral surface Y of the bulging portion 32 is close to the inner peripheral surface of the cylinder 1, even without the direction changing portion 33. Since the inflow of the hydraulic oil in the meantime is suppressed and the direction changing portion 33 realizes the inflow suppression of the hydraulic oil more effectively, it may be intermittently formed.

  And since the direction change part 33 is formed in the bulging part 32, one end of piston 3 comes to exhibit a concave shape, Therefore, since the pressure side valve | bulb 5 is accommodated inside this concave shape, When pulling out the piston with the valve stacked from the needle ridge, it is easy to maintain the valve mounted state on the piston, and it is advantageous in that the assembly work of the shock absorber can be efficiently performed. Become.

  In addition, when the direction changing portion 33 is formed intermittently, it is advantageous in improving the yield of the material as compared with the case where the direction changing portion 33 is formed over the entire circumference.

  In the above description, the case where the outer seat portion 13 on which the pressure-side valve 5 is seated has the bulging portion 32 on the outer periphery at one end of the piston 3 has been described as an example. In place of or in addition to the above, the bulging portion is located at the other end of the piston 3 on which the expansion side valve 4 is laminated, and on the outer sheet portion where the outer peripheral side end of the expansion side valve 4 is seated. May be provided.

  In addition, in the above description, the bulging portion 32 is integrally provided on the outer periphery of the outer sheet portion 13, but from the point of the present invention, the bulging portion 32 can be used by using an adhesive or screwing. It may be provided on the outer periphery of the outer sheet portion 13 by so-called retrofitting, and in this case, there is an advantage that the present invention can be embodied in the existing piston 3.

  In the above description, the partition body is described as the piston 3 in the cylinder 1. However, instead of this, the partition body may be a valve disk constituting the base valve in the cylinder 1 although not illustrated. good.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Rod 2a Tip part 2b Step part 2c Tip screw part 3 Piston 3a, 3b Port 3c, 3d Recessed part 3e, 12 Boss part 4, 5 Valve 6 Piston nut 11 Opening window
13 Outer seat portion 14 Connecting portion 31 Piston ring 32 Swelling portion 33 Direction changing portion R1 One chamber R2 Other chamber S Spacing X End surface Y Outer peripheral surface

Claims (2)

A partition body provided in the cylinder, a seat portion formed at one end of the partition body and enclosing the opening of the opening port in the partition body, and seated on the seat portion so that the opening of the port can be opened. In the shock absorber, the opening area of the port is set gradually smaller toward the one chamber side,
The seat portion has a bulging portion on the outer periphery of the seat portion that suppresses a working fluid from flowing between the cylinder and the partition body,
An end surface of the bulging portion facing the one chamber is formed to be flush with an end surface of the sheet portion facing the one chamber,
The outer peripheral surface of the bulging part is formed flush with the outer peripheral surface of the partition wall,
The outer peripheral end portion of the bulging portion includes a direction changing portion that protrudes outward from one end of the partition body,
The shock absorber according to claim 1, wherein an inner peripheral surface of the direction changing portion is expanded in diameter toward the outside. The shock absorber according to claim 1, wherein a connecting portion between the direction changing portion and the bulging portion is subjected to spherical processing.

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