JP2006070991A - Buffer valve structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily center an annular shim in a valve structure provided with an annular shim for giving an initial deflection to a leaf valve, and to set the initial deflection of the leaf valve only by the thickness of the annular shim.
SOLUTION: A plurality of leaf valves 34 are stacked on a piston 33, an annular shim 50 is sandwiched between outer peripheral portions of two adjacent leaf valves 34, and a shock absorber that gives initial deflection to the leaf valve 34 is provided. In the valve structure, a bent collar 51 is provided on the outer periphery of the annular shim 50, and the annular shim 50 is engaged with the outer periphery of at least one leaf valve 34 to center the annular shim 50.
[Selection] Figure 2

Description

  The present invention relates to a shock absorber valve structure.

  As a conventional shock absorber valve structure, when a plurality of leaf valves are stacked on a valve body such as a piston, the leaf valve is given initial deflection to obtain a desired damping force characteristic. A thick annular shim is sandwiched between the outer peripheral portions of two adjacent leaf valves, and a thin centering plate for centering the annular shim is sandwiched between the inner peripheral portions. An initial deflection corresponding to the difference in thickness between the annular shim and the centering plate is applied to the leaf valve.

In addition, in the valve structure of the shock absorber disclosed in Patent Document 2, a structure in which an annular shim is welded to the above-described centering plate is disclosed.
JP2002-266923 JP2004-150574

  In the valve structure of Patent Document 1, an annular shim rides on the centering plate when the valve is assembled, and the annular shim is sandwiched between the centering plate and the leaf valve, and a desired damping force characteristic cannot be obtained. In addition, there is a problem that the difference in thickness between the centering plate and the annular shim affects the initial deflection of the leaf valve.

  The valve structure of Patent Document 2 has problems such as the number of man-hours for welding the centering plate and the annular shim and the occurrence of burrs.

  An object of the present invention is to simply center an annular shim in a valve structure provided with an annular shim for imparting an initial deflection to the leaf valve, and to set the initial deflection of the leaf valve only by the thickness of the annular shim.

  The invention according to claim 1 is a shock absorber valve in which a plurality of leaf valves are stacked on a valve body, an annular shim is sandwiched between the outer peripheral portions of two adjacent leaf valves, and initial deflection is applied to the leaf valves. In the structure, a bent collar is provided on the outer periphery of the annular shim, and the collar of the annular shim is engaged with the outer periphery of at least one leaf valve to center the annular shim.

  According to a second aspect of the present invention, in the first aspect of the present invention, the annular shim further comprises a collar portion at a plurality of positions along the circumferential direction of the outer periphery.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the annular shim is further provided with a flange portion on the upper and lower sides of the outer periphery.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the annular shim further includes a collar portion formed by press working.

(Claim 1)
(a) The annular shim is easily centered by engaging the collar portion with the outer periphery of the leaf valve, and is not mis-installed without being centered.

  (b) The initial deflection of the leaf valve can be set only by the thickness of the annular shim and can be easily changed.

(Claim 2)
(c) Since the annular shims are provided with flange portions at a plurality of positions along the circumferential direction of the outer periphery, there is no possibility of blocking the flow path provided in the valve body as compared with those provided with flange portions that are continuous in the circumferential direction. .

(Claim 3)
(d) Since the annular shim is provided with the flange portions on the upper and lower sides of the outer periphery, it is possible to eliminate the vertical direction of assembling with respect to the two upper and lower leaf valves sandwiching the annular shim.

(Claim 4)
(e) Since the annular shim includes a collar portion formed by press working, it can be easily manufactured.

  1 is an overall sectional view showing a hydraulic shock absorber according to a first embodiment, FIG. 2 is a sectional view showing a valve structure, FIG. 3 is a perspective view showing an annular shim, and FIG. 4 is a plan view showing an intermediate material of the annular shim. 5 is a sectional view showing the valve structure of Example 2, FIG. 6 is a sectional view showing the valve structure of Example 3, and FIG. 7 is a perspective view showing an annular shim.

Example 1 (FIGS. 1 to 4)
As shown in FIG. 1, the hydraulic shock absorber 10 is a single separation and pressurization type. A piston rod 12 is inserted into the cylinder 11, and a suspension spring (not shown) is interposed between the cylinder 11 and the piston rod 12. ing.

  The cylinder 11 includes a wheel side mounting member 14, and the piston rod 12 includes a vehicle body side mounting member 15. The elastic force of the suspension spring absorbs the impact force that the vehicle receives from the road surface.

  The cylinder 11 includes a rod guide 21 through which the piston rod 12 passes and is sealed to the open end. At this time, a stopper ring 22 is mounted on the inner periphery of the cylinder 11, and the rod guide 21 is prevented from coming off by the stopper ring 22. The rod guide 21 is liquid-tightly attached to the cylinder 11 via an O-ring 23, and the piston rod 12 is slidable in a liquid-tight manner in an inner diameter portion including an oil seal 24, a bush 25, and a dust seal 26. The oil seal 24 is held by the seal presser 24 </ b> A and is loaded in the inner concave portion of the rod guide 21.

  The cylinder 11 is provided with a cap member 27 outside the rod guide 21 and the dust seal 26. The cap member 27 has a substantially cup shape, and is fixed by press-fitting a side wall portion inside the opening end of the cylinder 11. The cap member 27 passes the piston rod 12 through the inner periphery of the perforated plate portion, directly faces the outer periphery of the piston rod 12 outside the seal lip of the dust seal 26, and is in a state through a minute gap with the outer periphery of the piston rod 12 To close the open end of the cylinder 11. The outer end surface of the perforated plate portion of the cap member 27 becomes a receiving surface of the bump rubber 28 provided on the piston rod 12 at the time of maximum compression, and regulates the maximum compression stroke.

  The cylinder 11 is provided with a rebound rubber 29 in a concave portion on the inner end surface of the rod guide 21. When the cylinder 11 is fully extended, the rebound rubber 29 is abutted against a rebound stopper 31 on the piston rod 12 side so that the extended stroke can be regulated.

  The hydraulic shock absorber 10 has a piston valve device (extension-side damping force generator) 30. The hydraulic shock absorber 10 suppresses expansion and contraction vibrations of the cylinder 11 and the piston rod 12 due to the absorption of the impact force by the suspension spring 13 by the damping force generated by the piston valve device 30.

  The piston valve device 30 is provided with a rebound stopper / valve stopper 31, a washer 31 A, a pressure side valve 32, a piston 33, an extension side valve 34, a washer 35 A, and a valve stopper 35 at the end of the piston rod 12 inserted into the cylinder 11. These are fixed with a nut 36.

  The piston 33 constitutes a valve body, fluidly slidably contacts the inside of the cylinder 11 via an O-ring 37A and a piston ring 37B provided on the outer peripheral portion, and the piston-side oil in which the piston rod 12 is not accommodated inside the cylinder 11 The chamber 38A is divided into a rod side oil chamber 38B in which the piston rod 12 is accommodated. The piston 33 includes a pressure side valve 32 configured by laminating a plurality of leaf valves, and a pressure side flow path 39 that allows the piston side oil chamber 38A and the rod side oil chamber 38B to communicate with each other, and a plurality of leaf valves. Are provided with an extension side flow path 40 that allows the piston side oil chamber 38A and the rod side oil chamber 38B to communicate with each other.

  Therefore, when the hydraulic shock absorber 10 is compressed, the oil in the piston side oil chamber 38A passes through the pressure side flow path 39, opens the pressure side valve 32, and is guided to the rod side oil chamber 38B.

  Further, when the hydraulic shock absorber 10 is extended, the oil in the rod-side oil chamber 38B passes through the extension-side flow path 40 to bend and deform the extension-side valve 34 and is guided to the piston-side oil chamber 38A, thereby generating an extension-side damping force. .

  The hydraulic shock absorber 10 is provided with a free piston 42 that separates the gas chamber 41 from the piston-side oil chamber 38 </ b> A inside the cylinder 11. The free piston 42 slides liquid-tightly inside the cylinder 11 through an O-ring 43 attached to the outer periphery. The volume of the oil chamber (38A, 38B) inside the cylinder 11 changes as the piston rod 12 advances and retreats with respect to the cylinder 11. The volume of the gas chamber 41 due to the sliding of the free piston 42 along the axial direction of the cylinder 11 changes. Compensate by change.

  However, the hydraulic shock absorber 10 has the following configuration in order to obtain a desired damping force characteristic by applying an initial deflection by applying a preload to the leaf valve of the expansion side valve 34.

  Of the plurality of leaf valves constituting the expansion side valve 34, one or a plurality of leaf valves on the side in contact with the end face of the valve seat where the expansion side flow path 40 of the piston 33 opens, and further laminated thereon. An annular shim 50 is sandwiched between the remaining leaf valves as shown in FIG. That is, the annular shim 50 has an inner diameter larger than the inner diameter of two adjacent leaf valves 34A and 34B (the leaf valve 34A is located closer to the end face of the valve seat of the piston 33). , 34B is sandwiched between the outer peripheral portions excluding a certain range of the inner peripheral portion in the diameter direction, and the leaf valve 34B supports the leaf valve 34A as a backup and presses against the end face of the valve seat. )give. The initial deflection given to the leaf valve 34B is adjusted by setting the thickness of the annular shim 50, and a desired damping force characteristic is obtained for the expansion side valve 34.

  As shown in FIG. 3, the annular shim 50 is provided with rib portions 51 that are bent at right angles (bent at a right angle with respect to the surface of the annular shim 50) at a plurality of positions along the circumferential direction of the outer periphery. Prepare. The annular shim 50 has a flange inner diameter formed by the inner surfaces of the flange portions 51 opposed in the direct direction slightly larger than the outer diameter of the leaf valve 34A (the flange inner diameter of this embodiment is equal to the outer diameter of the leaf valve 34B). The collar portion 51 is engaged with the outer periphery of the leaf valve 34A to center the annular shim 50 with respect to the leaf valve 34 (34A, 34B). The leaf valves 34 (34A, 34B) are centered by passing through their inner diameters with respect to the piston rod 12.

  Therefore, in the piston valve device 30 of the hydraulic shock absorber 10, one or more leaf valves 34 are mounted on the end face of the piston 33 around the piston rod 12. An annular shim 50 is placed on the uppermost leaf valve 34A, and the remaining leaf valve 34 including the leaf valve 34B is placed on the annular shim 50. These leaf valves 34 are nuts through washers 35A and valve stoppers 35. 36 (the nut 36 is screwed to the piston rod 12). By tightening the nut 36, an initial deflection corresponding to the thickness of the annular shim 50 is given to the inner peripheral side portion of the leaf valve 34B, and a preload based on this initial deflection is given to the leaf valve 34A. At this time, the annular shim 50 is securely centered by engaging with the outer periphery of the leaf valve 34A and does not shift with respect to the leaf valves 34A and 34B.

  The annular shim 50 is formed by stamping a material such as a steel plate with a press to obtain an intermediate material having a convex portion 52 on the outer periphery as shown in FIG. It can be manufactured by bending it into the collar portion 51.

According to the present embodiment, the following operational effects can be obtained.
(a) The annular shim 50 is easily centered by engaging the collar portion 51 with the outer periphery of the leaf valve 34A, and is not centered and misinstalled.

  (b) The initial deflection of the leaf valve 34B can be set only by the thickness of the annular shim 50 and can be easily changed.

  (c) Since the annular shim 50 includes the flange portions 51 at a plurality of positions along the circumferential direction of the outer periphery, the extension-side flow path 40 provided in the piston 33 compared with the flange portion 51 continuous in the circumferential direction. There is no risk of blocking.

  (d) Since the annular shim 50 includes the collar portion 51 formed by press working, it can be easily manufactured.

(Example 2) (FIG. 5)
The second embodiment differs from the first embodiment in that the inner diameter of the collar formed by the inner surfaces of the opposed collar portions 51 of the annular shim 50 is slightly larger than the outer diameter of the leaf valve 34B, and the collar portion 51 is made to be the leaf valve 34B. Is engaged with the outer periphery of the annular shim 50 so as to be centered with respect to the leaf valve 34 (34A, 34B) of the annular shim 50.

  Since the outer diameters of the leaf valve 34A and the leaf valve 34B are the same, the inner diameter of the flange formed by the inner surfaces of the opposing flange portions 51 of the annular shim 50 is slightly smaller than the outer diameter of both the leaf valve 34A and the leaf valve 34B. The flange 51 of the annular shim 50 engages with the outer periphery of either the leaf valve 34A or the leaf valve 34B to center the annular shim 50 with respect to the leaf valve 34 (34A, 34B). The direction of assembling with respect to 34A and 34B can be eliminated.

Example 3 (FIGS. 6 and 7)
The third embodiment is different from the first embodiment in that the annular shim 50 includes flange portions 51 (51A, 51B) on the upper and lower sides of the outer periphery. The collar portion 51A is bent upward at a right angle with respect to the surface of the annular shim 50, the collar portion 51B is folded downward at a right angle with respect to the back surface of the annular shim 50, and the collar portion 51A and the collar portion 51B are alternately arranged in the circumferential direction . The outer diameter of the leaf valve 34A and the leaf valve 34B with respect to the inner diameter of the collar formed by the inner surface of the collar portion 51A opposed in the diametrical direction of the annular shim 50 and the inner diameter of the collar portion 51B opposed in the diametrical direction. If both of the diameters are small and the inner diameter of the annular shim 50 is slightly larger than the outer diameter of at least one of the leaf valve 34A and the leaf valve 34B, the direction of assembling the annular shim 50 with respect to the leaf valves 34A and 34B can be lost. it can.

  That is, the annular shim 50 is sandwiched between the outer peripheral portions of the leaf valve 34A and the leaf valve 34B, and at least one of the flange portion 51A and the flange portion 51B is engaged with the outer periphery of at least one of the leaf valves 34A and 34B. The annular shim 50 can be centered with respect to the leaf valve 34 (34A, 34B).

  The embodiment of the present invention has been described with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like without departing from the gist of the present invention. Included in the invention. For example, the collar part with which the annular shim of this invention is provided may be continuous in the circumferential direction of the outer periphery.

  The leaf valve to which the annular shim of the present invention is applied may be a compression side valve.

  The valve body to which the annular shim of the present invention is applied is not limited to the piston provided on the piston rod, but may be a bottom piece provided on the bottom of the cylinder.

1 is an overall cross-sectional view showing a hydraulic shock absorber according to a first embodiment. FIG. 2 is a sectional view showing the valve structure. FIG. 3 is a perspective view showing an annular shim. FIG. 4 is a plan view showing an intermediate material of the annular shim. FIG. 5 is a cross-sectional view showing the valve structure of the second embodiment. FIG. 6 is a cross-sectional view showing the valve structure of the third embodiment. FIG. 7 is a perspective view showing an annular shim.

Explanation of symbols

10 Hydraulic shock absorber 33 Piston (valve body)
34 Stretching side valve, leaf valve 34A, 34B Leaf valve 50 Annular shim 51, 51A, 51B collar

Claims (4)

In the valve structure of the shock absorber, in which a plurality of leaf valves are stacked on the valve body, an annular shim is sandwiched between the outer peripheral portions of two adjacent leaf valves, and the leaf valve is initially deflected.
A valve structure for a shock absorber, comprising a bent collar portion on an outer periphery of an annular shim, and centering the annular shim by engaging the flange portion of the annular shim with an outer periphery of at least one leaf valve.   The valve structure of the shock absorber according to claim 1, wherein the annular shim includes flange portions at a plurality of positions along the circumferential direction of the outer periphery.   The valve structure of the shock absorber according to claim 1 or 2, wherein the annular shim includes flange portions on the upper and lower sides of the outer periphery.   The valve structure of the shock absorber according to any one of claims 1 to 3, wherein the annular shim includes a flange portion formed by pressing.

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