JP2581704Y2 - Hydraulic shock absorber - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic shock absorber interposed between a vehicle body of a vehicle such as an automobile and an axle to attenuate vibration from a road surface.

[0002]

2. Description of the Related Art As a conventional hydraulic shock absorber of this type, for example, one disclosed in Japanese Utility Model Laid-Open Publication No. 2-66242 is known.

In this hydraulic shock absorber, two bypasses are provided in a piston rod, and the two bypasses are opened and closed by needle valves provided at respective ends of push rods as two inner and outer adjuster rods inserted into the piston rod. The bypass is used as the expansion-side orifice, and another bypass is used as the compression-side orifice.

[0004]

In the above-mentioned conventional hydraulic shock absorber, since the push rod is composed of two inner and outer rods, the thickness of the piston rod is determined due to processing-related dimensional restrictions in the diameter direction. It is not possible to deal with things, and design is impossible or processing is difficult. In addition, when the push rod is made thinner, the rigidity is reduced, so that the control of the needle valve becomes difficult, or the operation touch is deteriorated.

Therefore, an object of the present invention is to provide a hydraulic shock absorber which can make the outer diameter of an adjuster rod for controlling a bypass thinner, can cope with the thickness of a piston rod, does not cause a reduction in rigidity, and is easy to machine. That is.

[0006]

Means for Solving the Problems In order to achieve the above object, a configuration of the present invention is such that a piston rod is movably inserted into a cylinder via a piston, and the piston has a rod-side oil chamber and a piston inside the cylinder. The two oil chambers communicate with each other through the expansion port and the compression port provided on the piston, and a growth leaf valve and a compression leaf valve are provided at each outlet of the expansion port and the compression port. In a hydraulic shock absorber that can be freely opened and closed, a piston rod is provided with an extension side bypass and a pressure side bypass that communicate the two oil chambers,
The extension side bypass and the compression side bypass are respectively opened toward the back side from the pressure receiving side of the extension side leaf valve and the compression side leaf valve, and a check valve is provided at each outlet end so as to be openable and closable. A first valve body that opens and closes the extension-side bypass in accordance with the vertical movement of the adjuster rod is provided at the tip of the adjuster rod, and the adjuster rod is rotated by the rotation of the adjuster rod. Accordingly, a second valve element for opening and closing the pressure side bypass is provided.

[0007]

When the adjuster rod is moved in the axial direction, the first valve body at the tip adjusts the opening area of the extension side bypass, and when the adjuster rod is rotated, the second valve body moves up and down to reduce the opening area of the compression side bypass. adjust.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. A hollow piston rod 3 is movably inserted into a cylinder 1 via a piston 2, and the piston 2 partitions a rod-side oil chamber 4 and a piston-side oil chamber 5 in the cylinder 1.

The piston 2 is formed with an expansion port 6 and a compression port 7 which communicate the two oil chambers 4 and 5, and an expansion leaf valve 8 is provided at the outlet end of the expansion port 6 so as to be openable and closable. A pressure side leaf valve 9 is provided at the outlet end of the pressure side port 7 so as to be openable and closable.

A lower end of the piston rod 3 is provided with a center rod 14 also serving as a piston rod. The center rod 14 is provided with a sub-piston 11 via a nut 10. An extension side bypass 12 communicating the oil chambers 4 and 5 is formed, and a compression side bypass 13 is formed on the center rod 14. The extension side bypass 12 is formed from the pressure receiving surface side entrance of the extension side leaf valve 8 to the rear side exit,
The compression side bypass 13 is formed from the pressure receiving surface side (lower side in FIG. 1) inlet of the compression side leaf valve 9 to the rear side outlet. The extension side bypass 12 is formed from the pressure receiving surface side inlet of the extension side leaf valve 8 to the back side outlet, and the compression side bypass 13 is a back side outlet from the pressure receiving surface side (lower side surface in FIG. 1) inlet of the compression side leaf valve 9. It is formed toward.

An extension side check valve 15 is provided at the outlet of the extension side bypass 12 so as to be openable and closable opposite to the extension side leaf valve 8. Similarly, the exit of the compression side bypass 13 is opposed to the compression side leaf valve 9 and has a compression side check valve. A valve 16 is provided to be openable and closable.

The inside of the piston rod 3 and the center rod 14
An adjuster rod 17 is inserted therein so as to be freely movable in the rotational direction and the axial direction. A needle-shaped first valve element 18 is provided at the tip of the adjuster rod 17, and this valve element 18 is used to move the adjuster rod 17 up and down. With extension side bypass 12
Are opened and closed, and the opening area is adjusted.

A poppet-type second valve body 19 is vertically movably inserted into the outer periphery of the lower part of the adjuster rod 17 via a connection portion 20 having an irregular shape. When the adjuster rod 17 is rotated, the second valve body 1 is rotatably screwed into the formed screw portion 21.
9 rotates through a screw portion 21 and is guided in a vertical direction through an oddly-shaped coupling portion 20. At this time, the second valve body 19 opens and closes the compression-side bypass 13 to adjust the opening area thereof.

A bracket 21 connected to the vehicle body or axle side is connected to an outer end of the piston rod 3, and two first adjusters 22 and a second adjuster 23 are provided in the bracket 21.

A gear 24 is fitted into the outer end of the adjuster rod 17 in an irregular shape, and the outer end surface of the adjuster rod 17 is formed in a tapered shape.

The first adjuster 22 includes a bracket 21
A rotational drive member 25 is deformably fitted to the back portion, and a tapered surface 26 that is in contact with the outer end surface of the adjuster rod 17 is formed at the distal end.

Therefore, when the rotation drive unit 25 is rotated, the first
The adjuster 22 moves laterally, pushes the adjuster rod 17 downward through the tapered surface 26, and urges the first valve body 18 at the distal end in the closing direction.

A second adjuster 23 provided on the bracket B is rotatably disposed, and has a gear 2
8, the gear portion 28 meshes with the gear 24, and when the second adjuster 23 is rotated, the gear portion 28 and the gear 24 are rotated.
, The adjuster rod 17 rotates, and at this time, the lower second valve body 19 is rotated by the screw portion 21, and
It moves up and down along the deformed fitting portion 20 to adjust the opening area of the pressure side bypass 13. The second adjuster 23 is positioned at a set position by the detent ball 27.

When the piston rod 17 is extended, the piston 2 rises, and the oil in the rod-side oil chamber 4 deflects the expansion-side leaf valve 8 from the expansion port 6 and flows out to the piston-side oil chamber 5, and some oil Is the check valve 15 by the bypass 12
To flow out into the piston side oil chamber 5. At this time, the extension-side leaf valve 8 generates an extension-side damping force, and the magnitude of the damping force is controlled by the opening area of the first valve element 18 of the extension-side bypass 12.

Similarly, during compression, the oil in the piston side oil chamber 5 opens the pressure side leaf valve 9 from the pressure side port 7 and flows out to the rod side oil chamber 4, and part of the oil flows out from the pressure side bypass 13 by opening the check valve 16. . At this time, the compression side damping force is generated by the compression side leaf valve 16, and its magnitude is controlled by the opening area of the compression side bypass 13 by the second valve element 19.

FIG. 2 shows another embodiment of the present invention, which is a modification of the second valve body 19a. The other construction is the same as that of the embodiment of FIG. The detailed description of the same members will be omitted.

The second valve body 19a is a poppet-type valve body, and has a pin groove 29 formed in its body, and a pin 30 inserted into the adjuster rod 17 is fitted into this pin groove 29, and The valve element 19a is guided vertically along the pin 30 and the pin groove 29.

FIG. 3 shows another embodiment of the present invention in which the second valve body is deformed and the shape of the center rod 14a which also serves as a piston rod is slightly deformed. Since this embodiment is the same as the embodiment of FIG. 1, detailed description is omitted by assigning the same reference numerals.

The second valve body 19b is formed of a cylindrical body having a T-shaped cross section, and the second valve body 19b is normally urged in the closing direction of the pressure side bypass 13 by an upper spring 19c.

A cylindrical guide 19 d is vertically movably connected to the outer periphery of the adjuster rod 17 via a modified fitting portion 20 a, and the outer periphery of the guide 19 d is connected to a screw portion 21 formed on the inner periphery of the adjuster rod 17. It is screwed.

When the adjuster rod 17 is rotated, the guide 19d is moved up and down while rotating.
The spring load of d is adjusted, and the opening area of the pressure side bypass 13 according to the spring load of the spring 19d is set.

[0028]

According to the present invention, the following effects are obtained.

The first valve element and the second valve element are provided below the adjuster rod, and the first valve element and the second valve element are externally operated by rotating or vertically moving the adjuster rod. Therefore, only one adjuster rod is required, and the operability is improved. Further, since the outer diameter of the adjuster rod is not restricted by the thickness of the piston rod, workability and assemblability are good.

Since the first and second valve bodies are provided independently during the extension side bypass and the compression side bypass, the extension side damping force and the compression side damping force can be adjusted independently.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a hydraulic shock absorber according to an embodiment of the present invention.

FIG. 2 is a partial longitudinal front view of a hydraulic shock absorber according to another embodiment of the present invention.

FIG. 3 is a partial longitudinal front view of a hydraulic shock absorber according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder 2 Piston 3 Piston rod 4 Rod side oil chamber 5 Piston side oil chamber 6 Expansion side port 7 Pressure side port 8 Expansion side leaf valve 9 Pressure side leaf valve 12 Oil side bypass 13 Pressure side bypass 15, 16 Check valve 17 Adjuster rod 18 1 valve body 19, 19a, 19b Second valve body

Claims (1)

(57) [Scope of request for utility model registration] A piston rod is movably inserted into a cylinder via a piston, the piston partitions a rod-side oil chamber and a piston-side oil chamber in the cylinder, and two oil chambers are provided on the piston. In a hydraulic shock absorber in which the expansion-side leaf valve and the compression-side leaf valve are openably and closably provided at the outlets of the expansion-side port and the compression-side port, respectively, the piston rod has two oil chambers. The expansion side bypass and the compression side bypass are provided, and the expansion side bypass and the compression side bypass are respectively opened from the pressure receiving side of the expansion side leaf valve and the compression side leaf valve to the back side, and a check valve is opened and closed at each outlet end. The adjuster rod, which is freely movable in the rotational and axial directions, is inserted into the piston rod, and the adjuster rod is inserted into the tip of the adjuster rod. A first valve element is provided for opening and closing the extension side bypass in accordance with the vertical movement of the tar rod, and a second valve element for opening and closing the pressure side bypass in accordance with the rotation of the adjuster rod is provided on the adjuster rod. A hydraulic shock absorber characterized in that: