JP2008274991A - Piston valve device for hydraulic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piston valve device for a hydraulic shock absorber, having improved assembling efficiency while imparting a stable preset load to a disc valve, reducing damping force and finely widening the adjusting range of damping force. <P>SOLUTION: The piston valve device 20 for the hydraulic shock absorber comprises a valve seat 32 having a smaller diameter than the disc valve 31 and provided on the back face of the disc valve 31 abutting on a piston 13, a ball retainer 33 having a larger diameter than the valve seat 32 and arranged on the back face of the valve seat 32, and balls 34 each having a diameter larger than the sum of the thickness of the ball retainer 33 and the thickness of the valve seat 32 and held in ball holding holes 38 provided in a plurality of peripheral positions of the ball retainer 33. The balls 34 are thrust by a valve spring 35 arranged on the back face of the ball retainer 33, until the balls 34 abut on the back face of the disc valve 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a piston valve device for a hydraulic shock absorber.

In a piston valve device of a hydraulic shock absorber, a preset load is applied to a disk valve that is in contact with the piston, and the valve opening pressure due to the deflection deformation of the disk valve is adjusted, so that the damping force characteristic can be adjusted. There is something. The piston valve device described in Patent Document 1 is arranged between two disc valves that overlap each other and elastically deformable with the disc valve, and a centering disc between two disc valves that overlap each other. And a set ring that is thicker than the centering disk and provides the disk valve with an initial deflection that blocks the piston flow path (see FIG. 3C). It is.
JP-A-11-82597

The piston valve device described in Patent Document 1 has the following problems.
(1) The set ring is simply inscribed on the outer peripheral surface of the centering disc, and when a large input with high piston speed is repeated, the set ring is displaced and bites between the centering disc and the disc valve. May vary.

  (2) Since the deflection of the centering disc is added to the disc valve after the disc valve is blown by receiving a valve opening pressure larger than the preset load based on the initial deflection applied by the set ring, the deflection of the centering disc The damping force increases by the rigidity.

  (3) Although the preset load applied to the disc valve can be adjusted by changing the plate thickness difference between the set ring and the centering disc, the adjustment range of the damping force is narrow and fine adjustment is not possible.

  (4) The set ring is simply inscribed on the outer peripheral surface of the centering disc, and the set ring is not easily assembled.

  An object of the present invention is to provide a stable preset load to a disk valve in a piston valve device of a hydraulic shock absorber, to reduce a damping force, to make a wide adjustment range of the damping force, and to improve an assembling property. It is in.

  According to the first aspect of the present invention, a piston is fixed to an insertion end of a piston rod slidably inserted into a damper cylinder, the interior of the damper cylinder is partitioned into two oil chambers by the piston, and two oils are provided to the piston. A disk that contacts a piston in a piston valve device of a hydraulic shock absorber provided with a disk valve that forms a flow path communicating with the chamber and opens and closes the flow path facing the flow path formed in the piston A ball holding hole having a valve seat having a diameter smaller than the diameter of the disc valve on the back surface of the valve, a ball retainer having a diameter larger than the diameter of the valve seat disposed on the back surface of the valve seat, and provided at a plurality of circumferential positions of the ball retainer. A ball having a diameter larger than the sum of the thickness of the ball retainer and the thickness of the valve seat is held on each of the balls, and a bar disposed on the back surface of the ball retainer. By pressing the ball by the wave spring is obtained so as to hit the ball into the back of the disk valve.

  According to a second aspect of the present invention, in addition to the first aspect of the present invention, the balls held in the plurality of ball holding holes provided in the ball retainer have different ball diameters.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the plurality of ball holding holes provided in the ball retainer have their radial positions different from each other.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the ball holding hole provided in the ball retainer holds the ball movably in the plate thickness direction of the ball retainer, and the ball A retaining means for preventing the retaining hole from falling off is provided.

(Claim 1)
(a) As a structure for giving initial deflection to the valve spring for applying a preset load to the disk valve, a step based on the difference between the ball diameter and the thickness of the valve seat and the ball retainer is used. Since the ball diameter and valve seat and ball retainer plate thickness can be easily increased with high dimensional accuracy and inexpensive bearing balls and plate materials in general commercial materials, it is possible to form uniform steps with high accuracy, A stable preset load can be applied to the disc valve.

  (b) Since the disc valve is blown by receiving a valve opening pressure larger than the preset load based on the initial deflection of the valve spring applied by the ball, the disc valve is not added like the deflection stiffness of the conventional centering disc. The damping force can be lowered (FIG. 3).

  (c) The preset load applied to the disc valve is the ball diameter, arrangement (circumferential position and radial position of the ball holding hole provided in the ball retainer) and number, valve seat diameter and plate thickness, valve spring spring constant. In addition, by easily changing a plurality of elements such as the number of sheets, the adjustment range of the damping force can be set widely and finely.

  (d) Since the disc valve is partially pressed on the entire disc surface by a plurality of balls, when the valve is opened, it starts to open from a location where the ball is not pressed or a location where the press is weak. Thus, the blow characteristic of the damping force becomes a smooth curve with no bending point (FIGS. 4 and 5).

(Claim 2)
(e) The balls held in the plurality of ball holding holes provided in the ball retainer are made different in diameter from each other, whereby the above-described steps formed by the balls are made different from each other. As a result, the valve spring gradually opens the respective parts of the disc valve by making different preset loads applied to the respective parts of the disc valve via the respective balls. The adjustment range of the damping force can be set more finely.

(Claim 3)
(f) The plurality of ball holding holes provided in the ball retainer differ in their radial positions so that the contact points of the balls with respect to the disc valve differ. As a result, the valve spring gradually opens the respective parts of the disc valve by making different preset loads applied to the respective parts of the disc valve via the respective balls. The adjustment range of damping force can be set more finely.

(Claim 4)
(g) A ball holding hole provided in the ball retainer is provided with a retaining means for holding the ball movably in the thickness direction of the ball retainer and preventing the ball retainer from falling off. Therefore, the assembling property can be improved.

  1 is a cross-sectional view showing a piston valve device of a hydraulic shock absorber, FIG. 2 is a plan view showing a ball retainer, FIG. 3 is a schematic diagram showing damping force characteristics of the present invention example and a conventional example, and FIG. FIG. 5 is a schematic diagram showing the blow characteristics of the present invention. FIG. 6 is a schematic diagram showing the ball retaining means of the ball retainer.

  The present invention can be applied, for example, as a piston valve device for a hydraulic shock absorber described in JP-A-2002-333051. This hydraulic shock absorber is a double cylinder type in which a damper cylinder 11 as shown in FIG. 1 is provided in the outer tube, and a piston rod 12 is slidably inserted into the damper cylinder 11 so that the lower end portion of the outer tube is formed. The side is connected to the wheel side, and the upper end side of the piston rod 12 is connected to the vehicle body side. The hydraulic shock absorber has a suspension spring interposed between a lower spring seat fixed to the outer periphery of the outer tube and an upper spring seat provided at the upper end portion of the piston rod 12.

  The hydraulic shock absorber includes a piston valve device 20 provided in a piston 13 fixed to an insertion end of the piston rod 12 into the damper cylinder 11, an oil chamber inside the damper cylinder 11, and a reservoir between the damper cylinder 11 and the outer tube. A base valve device (not shown) is provided on a bottom piece fixed to the lower end of the damper cylinder 11 so as to partition the chamber. The damping force generated by the piston valve device 20 and the base valve device suppresses the expansion and contraction vibration of the piston rod 12 accompanying the absorption of the impact force by the suspension spring. Hereinafter, the piston valve device 20 will be described in detail.

  As shown in FIG. 1, the piston valve device 20 includes a valve stopper 22, a valve seat 23, a check valve 24, a piston 13, a disk valve 31, a valve seat 32, and a ball retainer described in detail later. 33, a ball 34, a valve spring 35, a washer 36, and a spring retainer 37 are inserted and fixed with a nut 25, and the outer end surface of the piston rod 12 is further crimped to secure the nut 25. Yes. The piston 13 divides the inside of the damper cylinder 11 into a piston-side oil chamber 40A in which the piston rod 12 is not accommodated and a rod-side oil chamber 40B in which the piston rod 12 is accommodated, and the both oil chambers 40A and 40B communicate with each other. The pressure side channel 41A and the extension side channel 41B are provided. The pressure side channel 41A is opened and closed by the check valve 24, and the extension side channel 41B is opened and closed by the disc valve 31.

  As a result, in the piston valve device 20 of the hydraulic shock absorber 10, during compression, the oil in the piston-side oil chamber 40A passes through the pressure-side flow path 41A to bend and deform the check valve 24 and open to the rod-side oil chamber 40B. Led. Further, at the time of extension, the oil in the rod side oil chamber 40B passes through the extension side flow passage 41B to bend and open the disk valve 36 and is guided to the piston side oil chamber 40A to generate an extension side damping force.

  However, the piston valve device 20 has the following configuration when the piston 13 is provided with the above-described disk valve 31 that opens and closes the flow path 41B facing the extension-side flow path 41B formed in the piston 13. .

  As shown in FIGS. 1 and 2, the piston valve device 20 has a round surface (the entire circumference of the extension side channel 41 </ b> B) in which the extension side channel 41 </ b> B of the piston 13 opens toward the piston side oil chamber 40 </ b> A. The disc valve 31 is brought into contact with the disc valve 31 so that the disc valve 31 has a smaller diameter than the diameter of the disc valve 31 on the back surface of the disc valve 31 (smaller than the region in which the expansion-side channel 41B of the piston 13 is open). ) Valve seat 32 (the outer edge of the valve seat 32 serves as a deflection fulcrum of the disc valve 31), and the rear surface of the valve seat 32 has a diameter larger than the diameter of the valve seat 32 (has a larger diameter than the disc valve 31). Of the ball retainer 33 and the ball retainer hole 38 provided at a plurality of positions in the circumferential direction of the ball retainer 33, the thickness of the ball retainer 33 and the thickness of the valve seat 32. More holds the ball 34 consisting of large-diameter bearings ball, hit the ball 34 to press the ball 34 by a valve spring 35 disposed on the rear surface of the ball retainer 33 elastically to the back of the disk valve 31.

  In the piston valve device 20, the valve spring 35 is given an initial deflection by a step based on the difference between the diameter of the ball 34 and the total plate thickness of the valve seat 32 and the ball retainer 33. The disc valve 31 is given a preset load based on the initial deflection of the valve spring 35 via the ball 34, and a damping force is set by the preset load and its own deflection rigidity.

Hereinafter, the operation of the disc valve 31 in the piston valve device 20 will be described.
(Damping force characteristics of the present invention and the conventional example) (FIG. 3)
In the example of the present invention shown in FIG. 3B, as the piston speed increases, the disk valve 31 is blown by receiving a valve opening pressure larger than a preset load based on the initial deflection of the valve spring 35 applied from the ball 34. (Blow region P), the disk valve 31 bends against its own bending rigidity and the load of the valve spring 35, and generates a damping force based on this bending deformation.

  In the conventional example shown in FIG. 3C, as the piston speed increases, the preset load based on the initial deflection of the valve spring 35 (disc valve in Patent Document 1) to which the disc valve 31 is applied by the set ring 1 is applied. After blowing by receiving a large valve opening pressure (blow region P), the disk valve 31 is bent and deformed against not only its own bending rigidity and the load of the valve spring 35 but also the bending rigidity of the centering disk 2. Generates a large damping force based on deflection deformation.

  The damping force F1 of the example of the present invention is lower than the conventional example of F2, as the deflection rigidity of the centering disk 2 is not added.

(Blow characteristics of the present invention example (1)) (Fig. 4)
In the example of the present invention, when the ball 34 having the same diameter is held in the ball holding holes 38 provided at two positions (with the same radius position) spaced 180 degrees in the circumferential direction of the ball retainer 33, the disc valve 31 is 4 starts to open from the left and right 90 degree range A of FIG. 4B without the pressing of 34 (first blowing point P1 of FIG. 4A), and then the upper and lower of FIG. The 90-degree range B opens and blows (second blow point P2 in FIG. 4A).

  That is, the blow region P shown in FIG. 3 of the disc valve 31 is finely provided with the first blow point P1 and the second blow point P2 of FIG. It becomes a smooth curved line without.

(Blow characteristics of the present invention example (2)) (Fig. 5)
In the example of the present invention, the balls 34 held in the plurality of ball holding holes 38 provided in the ball retainer 33 have different diameters. That is, of the ball holding holes 38 provided at four positions (equal radius positions) spaced 90 degrees in the circumferential direction of the ball retainer 33, the ball holding hole 38 positioned on one diameter has a large diameter (for example, 1.2. When the ball 34 having a small diameter (1.15 mm) is held in the ball holding hole 38 positioned on the other one diameter, the disc valve 31 does not hold the ball 34 (see FIG. 5). B) starts to open from four oblique areas A and blows (first blow point P1 in FIG. 5A), and then pressed by a small-diameter ball 34 (small initial deflection of the valve spring 35). 5) open and blow (second blow point P2 in FIG. 5A), and then pressed by a large diameter ball 34 (large initial deflection of the valve spring 35). ) Two upper and lower ranges C are open And blow (third blow point P3 in FIG. 5A).

  That is, the blow region P shown in FIG. 3 of the disc valve 31 is finely divided into the first blow point P1, the second blow point P2, and the third blow point P3 shown in FIG. And has a smooth curved line with no bending point.

  Further, in the piston valve device 20, the plurality of ball holding holes 38 provided in the ball retainer 33 can make their radial positions different from each other. That is, as shown in FIG. 2, the ball holding hole 38A provided in the large diameter position and the ball holding hole 38B provided in the small diameter position are mixed, and the ball 34 held in the ball holding hole 38A provided in the large diameter position is weak. The disk valve 31 is pressed by force (because of the valve spring 35), and the ball 34 held in the ball holding hole 38B provided at the small diameter position presses the disk valve 31 with a strong force (because of the valve spring 35). Accordingly, the disk valve 31 is held by the ball 34 of the ball holding hole 38A provided at the large diameter position where the pressure is weak, and the ball 34 of the ball holding hole 38B provided at the small diameter position is used as the deflection fulcrum. Blowing is started, and then, the range of the disk valve 31 pressed by the ball 34 of the ball holding hole 38B provided at a small diameter position where pressing is strong is opened and blown with the outer edge of the valve seat 32 as a fulcrum.

  In detail, the ball holding hole 38 provided in the ball retainer 33 of the piston valve device 20 holds the ball 34 movably in the plate thickness direction of the ball retainer 33 as shown in FIG. A retaining means 39 is provided for preventing the dropout of the ink. That is, the ball retainer 33 accommodates the ball 34 in the ball holding hole 38, and then crimps the periphery of the opening on the front and back of the ball holding hole 38 as indicated by the annular groove 39 </ b> A. A ball retaining claw 39B having a smaller inner diameter is formed.

According to the present embodiment, the following operational effects can be obtained.
(a) As a structure for giving an initial deflection to the valve spring 35 for applying a preset load to the disc valve 31, a step based on the difference between the diameter of the ball 34 and the thickness of the valve seat 32 and the ball retainer 33 is used. Since the diameter of the ball 34 and the thickness of the valve seat 32 and the ball retainer 33 can be easily increased with high dimensional accuracy and inexpensive bearing balls and plate materials in general commercial materials, high-precision and uniform steps can be obtained. It can be formed, and a stable preset load can be applied to the disk valve 31.

  (b) After the disk valve 31 is blown by receiving a valve opening pressure larger than a preset load based on the initial deflection of the valve spring 35 applied by the ball 34, the disk valve 31 is subjected to the bending rigidity of the conventional centering disk. Since there is no addition, the damping force can be lowered (FIG. 3).

  (c) The preset load applied to the disk valve 31 includes the diameter of the ball 34, the arrangement (the circumferential position and the radial position of the ball holding hole 38 provided in the ball retainer 33) and the number thereof, the diameter and thickness of the valve seat 32, By easily changing a plurality of elements such as the spring constant and the number of the valve springs 35, the adjustment range of the damping force can be set widely and finely.

  (d) Since the entire disc surface is partially pressed by the plurality of balls 34, the disk valve 31 starts to open from the portion where the ball 34 is not pressed or the portion where the ball 34 is weakly pressed, and finally all Will open, and the blow characteristic of the damping force will be a smooth curve with no inflection point (FIGS. 4 and 5).

  (e) The balls 34 held in the plurality of ball holding holes 38 provided in the ball retainer 33 have different ball diameters so that the steps formed by the balls 34 are made different from each other. As a result, the valve spring 35 gradually opens the respective parts of the disc valve 31 by making the preset loads applied to the respective parts of the disc valve 31 through the balls 34 different from each other. The adjustment range of damping force can be set more finely.

  (f) The plurality of ball holding holes 38 provided in the ball retainer 33 make their radial positions different from each other, whereby the contact points of the balls 34 with the disk valve 31 are made different from each other. As a result, the valve spring 35 gradually opens the respective parts of the disc valve 31 by making the preset loads applied to the respective parts of the disc valve 31 through the balls 34 different from each other. The adjustment range of damping force can be set more finely.

  (g) A ball holding hole 38 provided in the ball retainer 33 holds the ball 34 movably in the plate thickness direction of the ball retainer 33, and a retaining means 39 for preventing the ball retainer 33 from falling off. Prepared. Therefore, the assembling property can be improved.

  The embodiment of the present invention has been described in detail 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. It is included in the present invention. For example, the piston valve device of the present invention can be applied not only to a disc valve that generates an extension side damping force, but also when a preset load is applied to the compression side disc valve.

FIG. 1 is a cross-sectional view showing a piston valve device of a hydraulic shock absorber. FIG. 2 is a plan view showing the ball retainer. FIG. 3 is a schematic diagram showing damping force characteristics of the present invention example and the conventional example. FIG. 4 is a schematic diagram showing the blow characteristics of the example of the present invention. FIG. 5 is a schematic view showing blow characteristics of the present invention. FIG. 6 is a schematic view showing a ball retaining means of the ball retainer.

Explanation of symbols

11 damper cylinder 12 piston rod 13 piston 20 piston valve device 31 disc valve 32 valve seat 33 ball retainer 34 ball 35 valve spring 38 ball holding hole 39 retaining means 40A, 40B oil chamber 41A, 41B flow path

Claims (4)

The piston is fixed to the insertion end of the piston rod slidably inserted into the damper cylinder,
The interior of the damper cylinder is partitioned into two oil chambers by a piston, and a flow path that connects the two oil chambers to the piston is formed.
In the piston valve device of the hydraulic shock absorber provided with the disk valve that opens and closes the flow path facing the flow path formed in the piston,
A valve seat having a diameter smaller than the diameter of the disc valve is provided on the back surface of the disc valve abutting on the piston, and a ball retainer having a diameter larger than the diameter of the valve seat is disposed on the back surface of the valve seat. A ball having a diameter larger than the sum of the thickness of the ball retainer and the thickness of the valve seat is held in each of the provided ball holding holes, and the ball is pressed by a valve spring disposed on the back surface of the ball retainer. A piston valve device for a hydraulic shock absorber, which is applied to the back surface of the disk valve.   2. The piston valve device for a hydraulic shock absorber according to claim 1, wherein balls held in a plurality of ball holding holes provided in the ball retainer have different ball diameters.   The piston valve device for a hydraulic shock absorber according to claim 1 or 2, wherein a plurality of ball holding holes provided in the ball retainer have their radial positions different from each other.   The ball holding hole provided in the ball retainer includes a retaining means for holding the ball movably in the thickness direction of the ball retainer and preventing the ball retainer from falling off. A piston valve device for a hydraulic shock absorber according to claim 1.

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