JPH06288419A - Hydraulic buffer device - Google Patents

Abstract

PURPOSE:To lighten a device and to prevent generation of contamination and distortion in a cylinder and the like by providing a cylinder deformation quantity controlling projection, which is deformed by actuation of a piston and a piston rod, close to the outer circumference of the cylinder in an outer shell. CONSTITUTION:Projections 15a, 15b, which approach the outer circumference of a cylinder 2A, and flat parts 16a, 16b, which follow the projections and project largely, are arranged in one or more positions in the longitudinal direction of an outer shell 9A. The projections 15a, 15b and the flat parts 16a, 16b face the cylinder 2A via a minute clearance. In this constitution, deformation, which is caused by an offset load of a piston rod and a piston, of the cylinder 2A is regulated by the projections 15a, 15b and the flat parts 16a, 16b, so that semipermanent deformation and the like is prevented.

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 provided on a two-wheeled vehicle or a four-wheeled vehicle to absorb vibration transmitted to a vehicle body and improve riding comfort.

[0002]

2. Description of the Related Art FIG. 5 is a partially cutaway front view of a conventional hydraulic shock absorber. In FIG. 5, reference numeral 1 denotes a piston, which is slidably provided in a cylinder 2 and operates. A compression side oil chamber 3 and an expansion side oil chamber 4 that contain oil are separated from each other.

Further, the piston 1 is provided with a piston valve 6 for generating a damping force.

Reference numeral 5 denotes a piston rod that is inserted into and removed from the cylinder 2, and the piston 1 is attached to the tip of the piston rod.

Reference numeral 7 is a base plate attached to the lower end of the cylinder 2 and is provided with a base valve 8 for generating a damping force.

Reference numeral 9 denotes an outer shell provided on the outer peripheral side of the cylinder 2, which forms an oil chamber 10 communicating with the pressure side oil chamber 3 via the base valve 8.

Further, in such a hydraulic shock absorber, when it receives a vibration due to a load variation applied between the piston rod 5 and the cylinder 2, the hydraulic oil corresponding to the intrusion volume of the piston rod 5 is supplied to the piston valve 6 and the base. Valve 8
Through the pressure side oil chamber 3, the expansion side oil chamber 4 and the oil chamber 10 to generate a damping force, which functions to damp the vibration.

By the way, in the above-mentioned hydraulic shock absorber, when an excessive impact energy is received in absorbing and relaxing the impact from the road surface, an unbalanced load acts on the piston rod 5, whereby the cylinder 2 passes through the piston 1. As a result, the piston 1 receives a bending force, which makes it difficult for the piston 1 to smoothly slide on the cylinder 2.

If the bending force is excessive and the cylinder 2 is used for a long period of time, the cylinder 2 is deformed and the function of the piston 1 is impaired, or the piston 1 is worn along with the cylinder 2 and the damping function is impaired. Finally, there were problems such as oil leakage.

On the other hand, as shown in FIG. 5, the support collar 12 is fixed to the outer periphery of the cylinder 2 or the inner periphery of the outer shell 9 to prevent the cylinder 2 from bending as described above. It has been proposed that it is possible to prevent wear of the piston 1 and the cylinder 2 and deterioration of the damping function.

[0011]

However, in the case where the support collar 12 is used, very strict dimensional tolerances are required for the inner and outer diameters of the support collar 12, the outer diameter of the cylinder 2, and the inner diameter of the outer shell 9, so that parts are required. In addition to being extremely expensive as a single item, there are problems that the holding force for the support collar 12 is unstable against vibrations from the road surface.

Further, the support collar 12 as a different component is pressed into the cylinder 2 or the outer shell 9 by a method such as press fitting.
Since it is fixed to the inner side, problems such as contamination occur and it is difficult to put it into practical use. In addition, the type such as the SP sheet that is welded to the outer shell 9 has inner diameter distortion, which causes restrictions on the position setting of the support collar 12. There was a point.

The present invention has been made by paying attention to the above-mentioned conventional problems. By omitting the use of a member for supporting a cylinder, the structure can be simplified, the weight can be reduced, and the cost can be reduced. An object of the present invention is to provide a highly functional hydraulic shock absorber capable of effectively preventing the occurrence of contamination and the occurrence of distortion of the cylinder and outer shell.

[0014]

A hydraulic shock absorber according to the present invention includes a piston slidably provided in a cylinder for partitioning a pressure side oil chamber and an expansion side oil chamber, and a piston attached to the piston. And a piston rod that moves in and out of the cylinder, and a piston valve provided in the piston,
A base valve provided at the lower end of the cylinder, and an outer shell provided on the outer peripheral side of the cylinder and forming an oil chamber communicating with the pressure side oil chamber via the base valve, the outer shell comprising: A protrusion for restricting the amount of deformation of the cylinder deformed by the operation of the piston rod and the piston is provided close to the outer circumference of the cylinder.

[0015]

In the outer shell of the hydraulic shock absorber according to the present invention, the projection approaching the outer circumference of the cylinder is provided by notching or press working, and the unbalanced load applied to the piston rod pushes the inner circumference of the cylinder through the piston to bend it. The force that acts on the cylinder, that is, the amount of deformation of the cylinder, is regulated by the protrusion.

Further, by making the gap between the protrusions or the minute gap between the protrusion and the outer periphery of the cylinder function as a throttle valve having a narrow flow passage, a high damping force is generated and the damping function can be improved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a main portion showing a relationship between a cylinder 2A and an outer shell 9A in a hydraulic shock absorber, and FIG. It is the sectional view on the AA line.

In the figure, the outer shell 9A includes projections 15a, 15b approaching the outer periphery of the cylinder 2A at one or more locations in the longitudinal direction, and a flat portion 16a as a projection projecting largely therefrom. 16b, both of which are opposed to the cylinder 2A via a minute gap.

Numeral 19 is a knuckle bracket attached to the outer periphery of the outer shell 9A for supporting the outer shell 9A.

The projections 15a and 15b can be easily formed by plastically deforming them by notching or pressing.

In the hydraulic shock absorber having such a structure, by forming the outer shell 9A as described above, the bending (deformation) of the cylinder 2A caused by the unbalanced load of the piston rod 5 and the piston 1 is prevented from occurring. Protrusions 15a, 15b and flat portions 16a, 16 formed on 9A
This is regulated by b, so that accidents such as semi-permanent deformation of the cylinder 2A and deformation of the piston 1 and the cylinder 2A, deterioration of the damping function, oil leakage, etc. due to this can be avoided in advance.

Further, the gap between the protrusions 15a and 15b and the minute gaps between the protrusions 15a and 15b, the flat portions 16a and 16b and the outer circumference of the cylinder 2A move with the intrusion of the piston rod 5. , Which can generate a high damping force, which is advantageous for application to position-dependent shock absorbers.

FIG. 3 is a transverse sectional view showing another embodiment of the present invention, and FIG. 4 is a longitudinal sectional view of the same. This is like a strut. The present invention is applied to the case where the concentrated portion can be predicted, and here, the protrusions 17 are provided so as to be drawn at equal intervals in the horizontal direction at the same level.

According to this, in addition to the same effects as those of FIGS. 1 and 2, the rigidity of the outer shell 9A itself in the input direction can be increased.

In this case as well, in order to obtain a high damping force, a minute gap g is provided between each protrusion 17 and the cylinder 2A.

As described above, according to the present invention, the bending of the cylinder 2A can be restricted only by the deformation of the outer shell 9A without using the conventional supporting collar for fixing the cylinder, and the entire circumference of the outer shell 9A can be restricted. By forming a smile gap g between the caulking and the cylinder 2A, a high damping force can be generated.

The shape, number and position of the protrusions 15a, 15b and 17 can be arbitrarily selected.
Protrusions 15a, 15b, 17 are provided on the portion where a large bending force is applied.
The effect is increased by providing.

[0028]

As described above, according to the present invention, the pistons slidably provided in the cylinder to separate the pressure side oil chamber and the expansion side oil chamber from each other, and the pistons attached to the pistons, A piston rod that moves in and out of the cylinder, a piston valve provided in the piston, a base valve provided at the lower end of the cylinder, and an outer peripheral side of the cylinder, and the pressure side oil through the base valve. An outer shell that forms an oil chamber communicating with the chamber, and a protrusion that restricts the deformation amount of the cylinder deformed by the operation of the piston rod and the piston is provided in the outer shell so as to be close to the outer circumference of the cylinder. Since it has a structure, it is possible to simplify the structure, reduce the weight, and reduce the cost without using accessory parts such as a supporting collar, and to assemble it. The can facilitate, contamination occurs and the cylinder, can reliably avoid occurrence of distortion of the outer shell, there is an effect that can be obtained which can enable further application to position-dependent shock absorbers.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a hydraulic shock absorber according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view showing a main part of a hydraulic shock absorber according to another embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing a main part of the hydraulic shock absorber in FIG.

FIG. 5 is a front view showing a conventional hydraulic shock absorber partially cut away.

[Explanation of symbols]

 1 Piston 2A Cylinder 3 Pressure Side Oil Chamber 4 Extension Side Oil Chamber 5 Piston Rod 6 Piston Valve 8 Base Valve 9A Outer Shell 10 Oil Chamber 15a, 15b, 17 Protrusion

Claims (1)

[Claims] 1. A piston which is slidably provided in a cylinder and separates one pressure side oil chamber and one expansion side oil chamber, and a piston rod which is attached to the piston and moves into and out of the cylinder. A piston valve provided on the piston, a base valve provided on the lower end of the cylinder, and an outer chamber provided on the outer peripheral side of the cylinder and forming an oil chamber communicating with the pressure side oil chamber via the base valve. In a double-cylinder type hydraulic shock absorber including a shell, a protrusion for restricting a deformation amount of the cylinder deformed by the operation of the piston rod and the piston is provided in the outer shell so as to be close to the outer periphery of the cylinder. Hydraulic shock absorber characterized in that