JPH0449399Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulic shock absorber that is interposed between the vehicle body and the axle of a vehicle such as an automobile or a motorcycle to damp vibrations from the road surface.

[Conventional technology]

As a conventional hydraulic shock absorber of this kind, one shown in FIG. 2, for example, has been developed.

This is cylinder 1 and piston 2 inside cylinder 1.
Piston rod 3 movably inserted through
and two oil chambers 4 and 5 divided into pistons,
The expansion port 6 and the pressure port 7 of the piston that communicate the two oil chambers 4 and 5, the expansion side main valve 8 provided at the outlet of the expansion port 6, and the check valve 9 provided at the outlet of the pressure port 7, It has a bypass 10 in the piston rod 3 that communicates the two oil chambers 4 and 5, an extension side sub-valve 11 provided at the outlet of the bypass 10, and a needle valve 12 provided in the bypass 10 for adjusting damping force. .

The main valve 8 and sub-valve 11 are tightened with a nut 13 screwed onto the piston rod 3.

The bypass 10 is sealed via a stop boss 14 and a seal 15 screwed onto the end of the piston rod 3.

[The problem that the idea aims to solve]

In the above-mentioned hydraulic shock absorber, the stop boss 14 is screwed together to seal the bypass 10, so there is a risk of it loosening due to vibration, etc. For this reason, it is necessary to caulk the end of the piston rod 3 to prevent it from loosening. Furthermore, since it is necessary to provide a seal 15 on the outer periphery of the stop boss 14 to prevent oil leakage, the assembly operation is troublesome and the number of parts increases.

Furthermore, the main valve 8 and the sub-valve 11 are tightened with a nut 13;
Since they are connected by screws, there is a risk of loosening due to vibrations, etc., and to prevent this, it is necessary to use an expensive locking nut such as a U-nut or a double nut. For this reason, it is less economical and less easy to assemble, and the use of a double nut requires a correspondingly longer piston rod.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydraulic shock absorber that has a simple structure, can seal a bypass, prevent nuts from loosening, and is easy to assemble and economical.

[Means to solve the problem]

In order to achieve the above purpose, the configuration of the present invention is as follows:
A piston rod is movably inserted into the cylinder via a piston, and the piston partitions two oil chambers inside the cylinder.The two oil chambers communicate through a port provided in the piston, and a bypass provided in the piston rod. A main valve and a sub-valve are provided at the piston port and the bypass outlet of the piston rod, respectively, so that they can be opened and closed.
The main valve is a hydraulic shock absorber held by a nut screwed onto the piston rod.A spherical plug member larger than the inner diameter of the bypass is press-fitted into the bypass end of the piston rod to seal the bypass and tighten the nut of the piston rod. This feature is characterized in that the diameter of the portion corresponding to the nut is enlarged to prevent the nut from loosening.

[Effect]

When the spherical plug member is press-fitted, the plug member seals the bypass and at the same time expands the diameter of the portion of the piston rod that corresponds to the nut, and at this time, the threaded joint between the piston rod and the nut is deformed and the nut does not loosen.

〔Example〕

An example of the implementation of the present invention will be described below based on FIG.

A piston rod 3 is movably inserted into the cylinder 1 via a piston 2, and the piston 2 defines two oil chambers 4 and 5 within the cylinder 1.

A valve holder 1 is attached to the lower outer periphery of the piston rod 3.
6, shim 17, check valve 9, piston 2, main valve 8, shim 17, sub-valve 11, support member 18, and shim 19 are inserted in series, and these members are connected to step 20 of piston rod 3 and nut 13. being held in place.

The nut 13 is screwed into the lower part of the piston rod 3 via a threaded portion 21, and tightens a valve member and the like.

The piston 2 is provided with an extension port 6 and a pressure port 7, and the two oil chambers 4 and 5 are communicated through each port 6 and 7, and a main valve 8 on the extension side is provided at the outlet of the extension port 6 so as to be openable and closable. A check valve 9 is provided at the outlet of the pressure port 7 so as to be openable and closable.

A bypass 10 is formed in the piston rod 3 and the dish-shaped support member 18, which communicates the two oil chambers 4 and 5.

The bypass 10 is composed of horizontal holes 22 and 23 formed in the piston rod 3, a vertical hole 24, and a notch 25 formed in the support member 18.
An expansion-side sub-valve 11 is provided at the mouth end of the notch 25, which is an outlet of the valve, so as to be openable and closable.

A needle valve 12 is movably inserted into the vertical hole 24 of the piston rod 3 along the axial direction.
The valve body of this needle valve 12 faces a hollow spacer 27 to adjust the opening area of the bypass 10.

The vertical hole 24 is open to the end of the piston rod 3, and a steel ball or other spherical plug member 26 having an outer diameter larger than the inner diameter of the vertical hole 24 is driven into the open end and press-fitted to open the vertical hole 24. It's sealed. When the plug member 26 is driven in, the vicinity of the threaded portion 21 of the piston rod 3 is pushed outward and expands in diameter, thereby causing the threaded portion of the nut 13 and the piston rod 3 to
The screw portion 21 on the side is deformed, and the nut 13 no longer loosens.

When the piston 2 is extended, the piston 2 moves to the left in the figure, and the oil in the oil chamber 4 pushes open the main valve 8 from the extension port 6 and flows into the oil chamber 5 and the bypass 1.
0, the sub-valve 11 is pushed open and the flow is separated, and a combined damping force is generated due to the deflection of the main valve 8 and sub-valve 11. During compression, oil in the oil chamber 5 pushes open the check valve 9 through the pressure port 7 and flows out into the oil chamber 4.

[Effect of idea]

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

Since the bypass is sealed simply by press-fitting the plug member, the ease of assembling the plug member is improved, and there is no need for a seal or the like to prevent oil leakage.

When the plug member is forcibly inserted, a portion of the piston rod is pushed by the plug member and expands in diameter, deforming the threaded portion corresponding to the nut, thereby preventing the nut screwed onto the piston rod from loosening. Therefore, there is no need to use locking nuts, double nuts, etc., and ease of assembly and economic efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinal front view of a hydraulic shock absorber according to an embodiment of the present invention, and FIG. 2 is a longitudinal front view of a conventional hydraulic shock absorber. 1... Cylinder, 2... Piston, 3... Piston rod, 4, 5... Oil chamber, 6, 7... Port, 8... Main valve, 10... Bypass, 1
1... Sub valve, 13... Nut, 26... Plug member.

Claims (1)

[Scope of utility model registration request] A piston rod is movably inserted into the cylinder via a piston, and the piston partitions two oil chambers inside the cylinder.The two oil chambers communicate through a port provided in the piston, and a bypass provided in the piston rod. A main valve and a sub-valve are provided at the piston port and the bypass outlet of the piston rod, respectively, so that they can be opened and closed, and the main valve is held by a nut screwed onto the piston rod. A hydraulic shock absorber in which a spherical plug member larger than the inner diameter of the bypass is press-fitted into the end of the bypass to seal the bypass, and a portion of the piston rod corresponding to the nut is expanded in diameter to prevent the nut from loosening.