JPS6317870Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic shock absorber, and more particularly to a hydraulic shock absorber having valves associated with each piston to generate a damping force when the piston rod is extended and retracted.

Generally, hydraulic shock absorbers for automobile suspensions generate damping force by causing liquid to flow through an orifice when the piston rod is moving at a low speed. However, when a hydraulic shock absorber generates a damping force, the reaction force is necessarily transmitted to a support of the hydraulic shock absorber, such as a vehicle body. Therefore, if a damping force is generated for any minute displacement of the wheel, which is the unsprung load of the hydraulic shock absorber, a reaction force will always be transmitted to the vehicle body, giving the occupants a rough and uncomfortable feeling.

Therefore, the purpose of the present invention is to provide a hydraulic shock absorber that does not generate a damping force for minute displacements of unsprung loads, but generates a damping force only when the displacement exceeds a predetermined value. be.

The present invention includes a cylinder, a piston slidably disposed within the cylinder, the piston having a space and a port opening in the axial direction of the cylinder and opening into the space; a piston rod whose upper end projects outward from the cylinder; and a partition member disposed within the space of the piston and movable in the axial direction of the cylinder within a limited range with respect to the piston. a partition member having a first port through which liquid flows when the piston rod is extended and a second port through which liquid flows when the piston rod retracts; The device includes a first valve body biased toward a lower end, and a second valve body disposed above the partition member and biased toward an upper end of the second port.

When a slight displacement of the unsprung load occurs, the partition member first undergoes a slight relative displacement with respect to the piston. No damping forces occur during this displacement of the partition member. If the displacement of the unsprung load disappears as it is, no reaction force will be generated on the support body, for example, the vehicle body. When the displacement of the unsprung load becomes even larger, the port and the valve body work together to generate a damping force.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the hydraulic shock absorber of the present invention includes a cylinder 10, a piston 12, a piston rod 14, a partition member 16, and two valve bodies 18, 20.
including.

In the illustrated example, the cylinder 10 is of a so-called monotube type. Therefore, a free piston (not shown) is disposed within this cylinder 10 at a distance from the piston 12 downward.

Piston 12 is slidably disposed within cylinder 10 . This piston 12 has a space 22 hollowed out from the lower end and a plurality of ports 24 that are opened in the axial direction of the cylinder 10 and open into the space 22.
and has. The piston 12 further includes a piston band 26 on its outer periphery, and a liquid chamber 28 above the piston 12.
and the lower liquid chamber 30 are kept liquid-tight.

The piston rod 14 is connected to the piston 1 at its lower end.
2. In the illustrated example, piston rod 14 is welded to piston 12. An upper end (not shown) of this piston rod 14 projects outwardly from the cylinder 10.

The partition member 16 is arranged within the space 22 of the piston 12. The partition member 16 is formed into a disk shape and is made of a rigid member that will not be deformed by the force of the maximum hydraulic pressure acting on the partition member 16 during use of the shock absorber. Partition member 1
6 has a first port 32 through which fluid flows when the piston rod 14 is extended, and a second port 34 provided at a position that does not interfere with the first port 32 through which fluid flows when the piston rod 14 retracts. It is preferable that a plurality of ports be provided and arranged at equal intervals in the circumferential direction.

A support portion 36 extends from the lower end of the piston 12 to the space 22.
is provided, and the partition member 1 is attached to this support portion 36.
6, and tighten the hexagon socket nut 38 to the support part 36.
The partition member 16 is screwed into the piston 12 and partitions the two liquid chambers 28, 30. In this case, the outer diameter of the partition member 16 and the support portion 36
There is a dynamic fit relationship between the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter, and the diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the inner diameter of the outer diameter part. The tightening of the nut 38 is adjusted so that the partition member 16 can move in the axial direction of the cylinder 10 between the shoulder 37 and the nut 38 within a limited range (l ₁ +l ₂ ). In this case, the range is determined by taking into consideration the magnitude of movement of the valve body with respect to minute irregularities on the road surface.

The first valve body 18 and the second valve body 20 are formed into an annular shape by a leaf spring. The first valve body 18 is located below the partition member 16, and the second valve body 20 is located below the partition member 16.
The partition members 16 are connected to each other by bolts and nuts 40 that are respectively disposed above the partition members 6 and pass through the partition members 16.
Fixed. As a result, the elasticity of both valve bodies causes the first valve body 18 to be connected to the first port 32.
At the lower ends of the second valve bodies 20 are respectively biased toward the upper ends of the second ports 34 . When installing both valve bodies, place the auxiliary valve body 42 made of a leaf spring on the lower side of the first valve body 18 and the auxiliary valve body 44 made of a leaf spring on the upper side of the second valve body 20. It is preferable to restrict the opening degree.

The inside of the cylinder 10 is filled with a liquid, such as oil, and the cylinder of the shock absorber is mounted on a wheel support part (not shown) that is an unsprung load, and the piston rod is mounted on a vehicle body that is a sprung load. When the wheel support portion slightly changes, for example, in the direction of extension while the vehicle is running, the partition member 16 moves downward relative to the piston 12. No damping force is generated during this movement. When the displacement further increases and the partition member 16 hits the nut 38, the partition member 16 cannot move any further.
The pressure generated in the liquid chamber 28 causes the first valve body 1 to
8 is pushed down and the oil flows into the first port 32.
flows through it and generates a damping force. Contrary to the above, when the wheel support moves in the contraction direction, the partition member 16 moves upward relative to the piston 12.

According to the present invention, no damping force is generated even if there is a minute displacement. Therefore, by installing the hydraulic shock absorber according to the present invention in a car, it is possible to eliminate the bumpy feeling when the wheels ride on minute irregularities and get on and off.

In addition, in place of the above example, when the cylinder is of a so-called twin tube type, which is composed of an inner cylinder and an outer cylinder arranged at a distance from the inner cylinder in the radial direction, the upper part of the above-mentioned interval is If it is filled with pressurized gas, it becomes a cylinder, which is a component of the present invention.

Next, the first and second valve bodies may be formed of a simple plate material, and the valve bodies may be biased toward the ends of the first and second ports, respectively, by coil springs.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing the main parts of the hydraulic shock absorber according to the present invention, with the partition member in a neutral position, and Fig. 2 is a cross-sectional view showing the connection between the piston and the partition member. be. 10: cylinder, 12: piston, 14: piston rod, 16: partition member, 18, 20: valve body, 22: space, 24, 32, 34: port.

Claims (1)

[Scope of utility model registration request] a cylinder, a piston slidably disposed in the cylinder in a fluid-tight manner, the piston having a space and a port opening in the axial direction of the cylinder and opening into the space; a piston rod that is connected at ends and whose upper end projects outwardly from the cylinder; and a piston rod that is disposed within the space of the piston and is movable in the axial direction of the cylinder within a limited range relative to the piston. a partition member, the partition member having a first port through which liquid flows when the piston rod is extended, and a second port through which liquid flows when the piston rod retracts; a first valve body biased toward a lower end of the port; and a second valve body disposed above the partition member and biased toward an upper end of the second port.
Hydraulic buffer.