JPH0442593Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a piston valve for a hydraulic shock absorber used in a vehicle suspension system or the like.

BACKGROUND ART Conventionally, hydraulic shock absorbers used in vehicle suspension systems, etc., have a cylinder filled with liquid with a piston defining two chambers, one of which is A damping force generating valve is attached to generate a damping force by displacing and circulating liquid from one liquid chamber to the other liquid chamber. The damping force generating valve is provided with a communication passage bored in the piston and communicating between one liquid chamber and the other liquid chamber, and a communication passage provided at one end of this communication passage to connect one liquid chamber to the other. A disc-shaped orifice plate that controls the flow rate of liquid displacing and circulating in the liquid chamber, a valve spring that applies a valve-opening force to this orifice plate via a roughly disc-shaped retainer plate, and a piston rod that is screwed to the tip. It consists of a substantially cylindrical valve collar that supports the valve spring and fastens and fixes the piston to the piston rod.

Problems to be Solved by the Invention In this conventional technology, the retainer plate, which contacts the orifice plate and transmits the valve closing force of the valve spring, is fitted onto the outer periphery of the valve collar so as to be movable in the axial direction. This allows the orifice plate to open and close. Further, the retainer plate is positioned in the radial direction by the fitting portion between the retainer plate and the piston valve collar, so that the retainer plate reliably contacts the orifice plate. Therefore, as the orifice plate opens and closes,
The inner periphery of the retainer plate and the piston valve collar come into sliding contact and the sliding part wears out, causing looseness in the fitting part between the retainer plate and the valve collar, allowing the orifice plate to open and close smoothly and accurately. It may become impossible to do so. or,
Since the contact area between the orifice plate and the retainer plate is a plane contact, when the orifice plate is bent and deformed, the contact area between the orifice plate and the retainer plate, that is, the point of action of the spring force of the valve spring is displaced in the radial direction, and the orifice plate Since the moment of the spring force acting on the damping force changes, there is a problem in that it is difficult to stably generate a damping force. SUMMARY OF THE INVENTION An object of the present invention is to provide a damping force generating valve for a hydraulic shock absorber that can solve the problems of the prior art.

Means for Solving the Problems That is, the damping force generating valve of the hydraulic shock absorber of the present invention is provided with a piston that defines a cylinder into two liquid chambers, and a communication passage that communicates the two liquid chambers. , a substantially disc-shaped orifice plate disposed at one end of the communication path and displacing liquid from one liquid chamber to the other liquid chamber to generate a damping force, and a retainer disposed adjacent to the orifice plate. The valve spring is composed of a plate and a valve spring that applies a valve closing force to the orifice plate through the retainer plate, and is slidably engaged with the outer circumference of the orifice plate at the outer circumferential end of the retainer plate to provide a valve spring that applies a valve closing force to the orifice plate through the retainer plate. A substantially cylindrical engaging portion for positioning is formed.

Function The retainer plate is positioned in the radial direction by engaging the engaging portion at the outer circumference of the retainer plate with the outer circumference of the orifice plate. There is no need for radial positioning of the plate.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a sectional view of a main part of a hydraulic shock absorber showing an embodiment of the present invention. In this figure, 1 is a cylinder filled with liquid, and 2 is a piston rod that passes through one end of this cylinder 1 and extends to the outside. 3 is a piston, and this piston 3
is fastened and fixed to the tip of the piston rod 2 by a valve collar 4, and reciprocates within the cylinder 1 together with the piston rod 2, defining the inside of the cylinder 1 into two liquid chambers A and B. This piston 3 has
A communication passage 5 is provided to communicate the liquid chamber A on one side and the liquid chamber B on the other side. Reference numeral 6 denotes a substantially disc-shaped orifice plate. This orifice plate 6 closes the open end of the other liquid chamber B side of the communication path 5, and prevents the liquid pressure in one liquid chamber A from exceeding a predetermined pressure during the extension stroke of the piston rod 2. When this happens, the valve opens by bending and deforms, displacing liquid from one liquid chamber A to the other liquid chamber B, and generating a damping force. Furthermore, this orifice plate 6
The inner peripheral end is the side surface of the piston 3 and the valve cover 4.
The outer circumferential side of the piston 3 is held in contact with the valve seat 3a of the piston 3 so that it can be bent and deformed. 7 is a retainer plate arranged adjacent to this orifice plate 6. An outer cylindrical portion 7a is bent at the outer periphery end of this retainer plate 7, and this outer cylindrical portion 7a
A plurality of rib convex portions 7e protruding radially inward are formed at equal intervals on the circumference (see FIG. 2), and the ribs 7e engage with the outer periphery of the orifice plate 6. An outer circumferential cylindrical portion 7a provided with a rib 7e is loosely fitted with a predetermined gap on the outer periphery of a valve seat 3a that is formed to protrude from the other liquid chamber B side open end of the communication passage 5. The outer cylindrical portion 7a and the ribs 7e constitute an engaging portion 70, and when the ribs 7e of the engaging portion 70 engage with the outer periphery of the orifice plate 6, the retainer plate 7 is moved in the radial direction. is positioned, and the flow of the liquid squeezed by the orifice plate 6 is rectified by the loosely fitting portion of the outer cylindrical portion 7a and the valve seat 3a. Further, an inner cylindrical portion 7b is bent at the inner periphery end of the retainer plate 7, and this inner cylindrical portion 7b is loosely fitted to the outer periphery of the valve collar 4, so that sliding contact between the retainer plate 7 and the valve collar 4 is established. Prevented. Furthermore, a substantially semicircular projection 7d that abuts the outer peripheral side surface of the orifice plate 6 is formed protruding from the flange portion 7c of the retainer plate 7. 8 is a valve spring;
This valve spring 8 is connected to the flange portion 7c of the retainer plate 7 and the flange portion 4 of the valve collar 4.
a, and applies a desired valve closing force to the orifice plate 6 via the retainer plate 7. The communication passage 5, the orifice plate 6, the retainer plate 7, the valve spring 8, and the valve collar 4 constitute a damping force generating valve 9. Reference numeral 10 denotes a check valve, and this check valve 10 connects a communication passage 11 formed in the piston 3 and a liquid chamber A on one side of this communication passage 11.
It consists of a check plate 12 that closes the side opening end, a check spring 13 that applies a weak spring force to the check plate 12 in the valve closing direction, and a support member 14 that supports the check spring 13. During stroke, liquid is allowed to flow from the other liquid chamber B to one liquid chamber A.

According to the structure of the above embodiment, in the retainer plate 7, the engaging portion 70 is fitted onto the outer periphery of the orifice plate 6, and the protrusion 7d of the flange portion 7c is biased against the outer periphery side surface of the orifice plate 6 by the valve spring 8. and are always in contact at a predetermined position. Therefore, when the piston rod 2 reciprocates, the retainer plate 7 and the orifice plate 6 move together in the axial direction (see FIG. 3). At this time,
Although relative movement occurs in the axial direction between the engaging portion 70 of the retainer plate 7 and the outer peripheral edge of the orifice plate 6, the amount of relative movement l is extremely small, and the fit between the retainer plate 7 and the orifice plate 6 is Since there is no rattling due to sliding wear on the parts, smooth operation of the orifice plate 6 is ensured, and the contact position between the protrusion 7d of the retainer plate 7 and the orifice plate 6, that is, the valve spring The spring force action of 8 is substantially constant without being affected by the amount of deflection of the orifice plate 6, and produces a stable damping force.

FIG. 4 shows another embodiment of the present invention, in which an outer cylindrical portion 7a of the retainer plate 7 is bent parallel to the outer periphery of the valve seat 3a with a predetermined gap. The flow of liquid passing between the valve seat 3a and the outer periphery of the valve seat 3a can be rectified more effectively.

Effects of the Invention As described above, the present invention provides a substantially cylindrical engagement member that slidably engages with the outer circumference of the orifice plate and positions the retainer plate in the radial direction. By forming a portion, the retainer plate can be positioned in the radial direction without the inner circumferential end of the retainer plate slidingly contacting other members,
Since it is possible to prevent the retainer plate from wobbling in the radial direction due to wear of the sliding portion of the retainer plate, smooth opening and closing operations of the orifice plate can be ensured. In addition, since the retainer plate does not make sliding contact with other parts, there is no need to heat or surface treat the retainer plate to improve its wear resistance. Manufacturing costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a hydraulic shock absorber showing an embodiment of the present invention, Fig. 2 is a front view of the same retainer plate, Fig. 3 is a diagram of the operating state of the damping force generating valve, and Fig. 4 is FIG. 3 is a sectional view of a main part of a damping force generating pulp showing another embodiment of the present invention. 1...Cylinder, 2...Piston rod, 3...
... Piston, 4 ... Valve collar, 5 ... Communication path, 6 ... Orifice plate, 7 ... Retainer plate, 7a ... Outer circumference cylindrical part, 7b ... Inner circumference cylindrical part, 7c ... Flange part, 7d ... ...protrusion, 7
e... Rib convex portion, 8... Valve spring,
9... Damping force generation valve, 70... Connection part, A,
B...liquid chamber.

Claims (1)

[Claims for Utility Model Registration] (1) A communication passage that is bored in the piston that defines the cylinder into two liquid chambers and that communicates the two liquid chambers; a substantially disk-shaped orifice plate that displaces and circulates liquid from one liquid chamber to the other liquid chamber to generate a damping force; a retainer plate disposed adjacent to the orifice plate; In a damping force generating valve of a hydraulic shock absorber comprising a valve spring that applies a valve closing force, a substantially cylindrical cylinder that slidably engages with the outer periphery of the orifice plate at the outer peripheral end of the retainer plate for radial positioning. A damping force generating valve for a hydraulic shock absorber, characterized in that an engaging portion having a shape is formed. (2) The engaging portion is composed of an outer cylindrical portion and a protruding portion protruding from the inner circumferential side of the outer cylindrical portion at multiple locations in the circumferential direction, and the protruding portion is provided on the outer periphery of the orifice plate. A damping force generating valve for a hydraulic shock absorber according to claim 1, characterized in that the damping force generating valve is engaged.