JP-7857125-B2 - Damping valves and shock absorbers

Inventors

• 安井 剛

Assignees

• カヤバ株式会社

Dates

Publication Date

20260512

Application Date

20220316

Claims (5)

1. A partition wall having an annular outer valve seat that is inserted into a cylindrical body and positioned radially by the cylindrical body alone, and which protrudes axially from one end in the axial direction, and a port provided on the inner circumference side of the outer valve seat, A rod inserted into the inner circumference of the partition wall, A valve stopper having an annular inner valve seat that faces one end of the partition wall and has a smaller outer diameter than the outer valve seat, The system includes an annular leaf valve interposed between the outer circumferential valve seat and the inner circumferential valve seat, which is set to open both inward and outward to open and close the port, The partition wall has an alignment portion that aligns the leaf valve with respect to the outer valve seat, and is movable radially relative to the rod. A damping valve characterized by the following features.
2. The damping valve according to claim 1, characterized in that the centering portion is a projection that protrudes axially from the outer peripheral side of the outer peripheral valve seat at one end of the partition body and abuts against the outer peripheral of the leaf valve.
3. The damping valve according to claim 1, characterized in that the centering portion is a projection that protrudes axially from the inner circumference side of the partition wall body relative to the port and abuts against the inner circumference of the leaf valve.
4. A main partition body is inserted into the cylindrical body, facing the aforementioned partition body in the axial direction, and has a main port. The damping valve according to any one of claims 1 to 3, further comprising a main valve that opens and closes the main port and is set to an opening pressure higher than the opening pressure of the leaf valve.
5. Cylinder and A piston rod inserted into the cylinder, A damping valve according to any one of claims 1 to 4, A shock absorber characterized in that the cylinder is the cylindrical body.

Description

This invention relates to damping valves and shock absorbers. A shock absorber, for example, comprises a cylinder, a piston movably inserted into the cylinder, and a piston rod also movably inserted into the cylinder and connected to the piston. It is interposed between the vehicle body and the wheels to exert damping force and suppress vibrations between the body and wheels. The damping force exerted by the shock absorber is generated by a damping valve and affects the ride comfort of the vehicle. In recent years, shock absorbers used in vehicle suspensions are required to exert sufficient damping force to suppress vibrations even when expanding and contracting at extremely low speeds, in order to improve ride comfort. To meet such demands, a damping valve may comprise a valve disc that is annular in shape, loosely fitted to the outer circumference of a piston rod so as to be movable in the axial direction, and has a port and an outer circumferential valve seat surrounding the outer circumference of the port; a valve stopper that is fixed to the piston rod and faces the valve disc in the axial direction, and has an annular inner circumferential valve seat whose outer diameter is smaller than the inner diameter of the outer circumferential valve seat; and a leaf valve interposed between the outer circumferential valve seat and the inner circumferential valve seat and set to open both inward and outward (see, for example, Patent Document 1). The damping valve exerts damping force by applying resistance to the flow of hydraulic fluid passing through the port using the leaf valve when the shock absorber expands and contracts at very low speeds. International Publication No. 2021/084956 This is a longitudinal cross-sectional view of a shock absorber equipped with a damping valve according to one embodiment.This is an enlarged cross-sectional view of the piston portion of a shock absorber equipped with a damping valve in one embodiment.This figure shows the damping force characteristics of a shock absorber equipped with a damping valve in one embodiment.This is an enlarged cross-sectional view of the piston portion of a shock absorber equipped with a damping valve in one modified example of one embodiment. The present invention will be described below based on the embodiments shown in the figures. As shown in Figures 1 and 2, the damping valve V1 in one embodiment comprises a sub-piston 2, which is an annular structure inserted into a cylindrical cylinder 1 and positioned radially by the cylinder 1 alone, having an annular outer valve seat 2c and a port 2d; a valve stopper 3 having an annular inner valve seat 3c facing one end 2b of the sub-piston 2; and an annular leaf valve 4 interposed between the outer valve seat 2c and the inner valve seat 3c, which is set to open both inward and outward to open and close the port 2d. This configuration is applied to a buffer D. On the other hand, the shock absorber D to which the damping valve V1 is applied comprises a cylinder 1, a piston rod 5 inserted into the cylinder 1 so as to be axially movable, a piston 6 as a main bulkhead attached to the piston rod 5 and inserted into the cylinder 1 so as to be axially movable , main valves 7 and 8 that open and close main ports 6a and 6b provided on the piston 6, and the damping valve V1. In the case of this shock absorber D, for example, it is used interposed between the vehicle body and the axle in a vehicle (not shown) to suppress vibrations of the vehicle body and wheels. The damping valve V1 and shock absorber D will be described in detail below. As shown in Figure 1, an annular rod guide 20 is attached to the upper end of the cylinder 1, and the lower end of the cylinder 1 is closed with a cap 14. A piston rod 5, with a piston 6 and a sub-piston 2 attached to its tip, is movably inserted into the cylinder 1. The piston rod 5 is slidably inserted into the rod guide 20 and is axially movable within the cylinder 1, with its axial movement guided by the rod guide 20. The cylinder 1 is divided into an extension chamber R1 and a compression chamber R2, both filled with liquid, by the piston 6 and sub-piston 2. In this embodiment, the liquid is hydraulic fluid, but other liquids such as water or aqueous solutions can also be used. Furthermore, within cylinder 1, below the pressure chamber R2, an air chamber G is defined by a free piston 9 that is slidably inserted into cylinder 1. When the piston rod 5 is displaced axially relative to cylinder 1, the free piston 9 expands and contracts axially relative to cylinder 1 in accordance with the volume change of the piston rod 5 within cylinder 1. This volume change in air chamber G compensates for the volume of the piston rod 5 moving in and out of cylinder 1. While the buffer D is described as a so-called single-cylinder type buffer, it may also be configured as a double-cylinder type buffer with a reservoir outside cylinder 1. Returning to the previous point, the piston rod 5 has a s