JPS6317873Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a shock absorber, and more particularly to a shock absorber of a type in which a cylinder is constituted by an inner cylinder and an outer cylinder, and a damping valve mechanism is disposed at the bottom of the inner cylinder.

In a shock absorber used in an automobile suspension, by making the characteristics of a damping valve mechanism provided at the bottom of the shock absorber variable, it is possible to obtain optimal damping characteristics depending on the driving situation. The damping valve mechanism generally has a structure in which a valve body with an orifice is pressed against a valve seat with a port by a coil spring, and when the piston speed in the shock absorber is low, it depends on the resistance when the oil passes through the orifice. In the so-called orifice region where the piston speed increases, the fluid moves the valve body away from the valve seat and depends on the resistance as the fluid passes through the port and the gap between the valve seat and the valve body. A damping force is generated in each case in the so-called port area.

Conventionally, the characteristics of a damping valve mechanism can be changed by (a) changing the range of the orifice area by changing the mounting load of the coil spring, and (b) changing the orifice area by changing the diameter of the orifice in some way. Something is being done that changes the characteristics of.

However, in the method (a), although the upper limit of the damping force in the orifice region is changed, the slope of the characteristic curve in the orifice region cannot be changed. Further, in the method (b) above, although the slope of the characteristic curve in the orifice region can be changed, the characteristics in the port region cannot be changed.

By the way, the characteristics of the shock absorber are preferably variable in (a) the slope of the characteristic curve in the orifice region, (b) the range of the port region, and (c) the slope of the characteristic curve in the port region.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a shock absorber in which the slope of the characteristic curve in the orifice region and the port region, as well as the range of the port region, can be varied.

The present invention is a shock absorber in which a bottom member is disposed at the lower end of an inner cylinder, and a valve seat member having a port is disposed above the bottom member with a space therebetween.
an auxiliary port that can communicate with the port; a valve body that contacts and separates from the periphery of the lower opening end of the port at a radially outer side of the auxiliary port; and a valve body that is biased toward the valve seat member. a rubber spring that surrounds the auxiliary port and is fixed to the valve body, and has an orifice communicating between the auxiliary port and the space at a portion where the diameter of the orifice can be changed; and an adjustment member that is attached to the bottom member so as to be movable in the axial direction and supports the rubber spring.

By changing the mounting load of the rubber spring using the adjustment member, the rubber spring changes the spring constant and the diameter of the orifice, thereby changing the characteristics of the shock absorber.

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

As shown in FIG. 1, the shock absorber of the present invention includes an inner cylinder 10, an outer cylinder 12 coaxially disposed at a distance from the inner cylinder 10, and an inner cylinder 10.
A bottom member 14 and a bottom lid 1 that connect the outer cylinder 12 and the outer cylinder 12.
6 and a valve seat member 18 disposed above the bottom member 14 with a space therebetween, the shock absorber is known per se and includes a damping valve mechanism configured as follows.

The valve seat member 18 includes a main body part 22 having a port 20 in the center and a connecting part 24 fixed to the lower end of the main body part 22 by caulking, and the lower end of the inner cylinder 10 is fitted to the outer periphery of the connecting part 24. . The lower end of the other connecting portion 24 is press-fitted into the bottom member 14 and the valve seat member 1
A chamber 26 is defined between the bottom member 14 and the bottom member 14 . This chamber 26 passes through the hole 28 and the inner cylinder 10
It communicates with the reservoir chamber 30 between the valve seat member 18 and the outer cylinder 12, and also communicates with the working chamber 32 above the valve seat member 18 through the port 20 of the main body portion 22.

The valve body 34 has an auxiliary port 36 that can communicate with the port 20 of the valve seat member 18.
The lower open end periphery 2 of the port 20 radially outwardly of the port 20
Contact 1 and leave. In the illustrated example, the valve body 34 integrally includes an annular contact portion 38 and a port forming portion 39 extending downward from the contact portion 38 in a cylindrical shape, and the contact portion 38 contacts the opening end periphery 21 . and,
In the contact state, auxiliary port 36 communicates with port 20.

A rubber spring 40 surrounds the auxiliary port 36 of the valve body 34 and is fixed to the valve body 34 to bias the valve body 34 toward the valve seat member 18 . In the illustrated example, the rubber spring 40 includes a connecting portion 42 formed in the shape of a truncated cone;
A bottom portion 43 is integrated with the connecting portion 42, and the connecting portion 42 is fitted into and bonded to the port forming portion 39 of the valve body 34. The connecting portion 24 has an orifice 44 . This orifice 44 is provided at a location where the diameter of the orifice can be changed when changing the mounting load of the rubber spring 40 using an adjustment member to be described later.
The orifice 44 is connected to the auxiliary port 36 and the bottom member 14.
The chamber 26 is a space between the valve seat member 18 and the valve seat member 18.
communicate with.

Rubber spring 40 has a spring seat 46 surrounding bottom 43. This spring sheet 46 is the rubber spring 4
It is preferable to provide this in order to maintain the zero configuration and reliably change the mounting load of the rubber spring.

The adjustment member 48 extends upward through the bottom cover 16, is screwed into the bottom member 14, and is movable relative to the bottom member 14 in the axial direction of the inner cylinder 10. The adjustment member 48 supports the rubber spring 40 by contacting the spring sheet 46 at its upper end, and by changing the amount of protrusion from the bottom member 14, the mounting load of the rubber spring can be changed. The adjustment member 48 is made liquid-tight by the seal member 50.

During current use, when the piston rod (not shown) is lowered, fluid in the working chamber 32 flows through the port 20, the auxiliary port 36, and the orifice 44 into the chamber 2.
6 and further enters the reservoir chamber 30 through the hole 28. At this time, a damping force is generated depending on the diameter of the orifice 44. When the piston rod descends even faster, the force of the oil pushing the valve body 34 becomes greater than the mounting load of the rubber spring 40, and the valve body 34 opens. This opening area is determined by the spring constant of the rubber spring 40 and the downward speed of the piston rod.

Therefore, when the adjustment member 48 is turned to move forward or backward to change the mounting load of the rubber spring 40, the spring constant changes, so the opening area can be changed. Also,
The diameter of the orifice 44 changes as the mounting load changes. Therefore, as shown in Figure 2, before the change, the orifice area exhibited the characteristic of OA until the speed reached V _A , but for example, if the spring constant of the rubber spring is increased, the range of the orifice area changes. Therefore, it becomes V _C , and its characteristic becomes OC. Then, the load transferred to the port region changes from F _A to F _C , and the characteristics of the port region change from AB to CD.

When the piston rod moves up, the oil in the reservoir chamber 30 passes from the chamber 26 through the return port 52, pushes up the non-return valve 54, and enters the working chamber 32.

According to the present invention, by changing the mounting load of the rubber spring having the orifice, the diameter of the orifice and the spring constant of the rubber spring can be changed. As a result, the slope of the characteristic curve in the orifice region, the range of the port region, and the slope of the characteristic curve in the port region can all be made variable, providing ideal characteristics as a shock absorber.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the essential parts of a shock absorber according to the present invention, and FIG. 2 is a characteristic curve diagram. 10: Inner cylinder, 12: Outer cylinder, 14: Bottom member, 1
8: Valve seat member, 20: Port, 26: Chamber,
34: Valve body, 36: Auxiliary port, 40: Rubber spring, 44: Orifice, 48: Adjustment member.

Claims (1)

[Scope of utility model registration request] A shock absorber in which a bottom member is disposed at the lower end of an inner cylinder, and a valve seat member having a port is disposed above the bottom member with a space therebetween, and has an auxiliary port that can communicate with the port, and has an auxiliary port that can communicate with the port. A valve body that contacts and separates from the periphery of the lower opening end of the port on the radially outward side of the port, and a rubber spring that biases the valve body toward the valve seat member, and that surrounds the auxiliary port and is attached to the valve body. a rubber spring fixed to the body and having an orifice communicating the auxiliary port and the space at a portion where the diameter of the orifice can be changed; and an adjustment member that supports a rubber spring.