JPH0749097Y2 - Hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a hydraulic shock absorber used in a suspension system of an automobile,
In particular, it relates to a double cylinder type hydraulic shock absorber.

2. Description of the Related Art A double-cylinder type hydraulic shock absorber is disclosed in, for example, Japanese Utility Model Laid-Open No. 1-94639, in order to recirculate the excess liquid in the cylinder inner cylinder to the reservoir chamber when the piston rod enters the piston rod. A passage for communicating the inside of the cylinder with the reservoir chamber is formed in the metal plate supporting portion of the rod guide that supports so as to reciprocate.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in this conventional example, the metal support of the rod guide is caulked and fixed to the cylinder outer cylinder, and the load at the time of bouncing or rebound of the vehicle is made of the metal plate. It is designed to act on the support. Therefore, it has been desired to provide a technique capable of forming a passage that connects the inside of the cylinder with the reservoir chamber without reducing the rigidity of the metal plate support portion.

Means for Solving the Problems The present invention has been made in order to meet the above-mentioned demands, and a metal plate that supports a cylinder outer cylinder forming a reservoir chamber between the cylinder inner cylinder and a piston rod so that the piston rod can reciprocate. Hydraulic pressure provided with a rod guide made of metal and a seal for sealing between the cylinder outer cylinder and the piston rod, and fixing the support portion of the rod guide and the mounting base of the seal to the end of the cylinder outer cylinder. In the shock absorber, a groove is formed in the mounting base of the seal, and a chamfer is formed at the outer peripheral end of the support portion of the rod guide. The groove and the chamfer communicate the cylinder inner cylinder with the reservoir chamber. It is characterized in that a passage is formed.

Operation Excess oil in the cylinder of the cylinder when the piston rod enters is returned to the reservoir chamber through the passage formed by the groove of the seal and the chamfered portion of the rod guide.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a hydraulic shock absorber showing an embodiment of the present invention. In FIG. 1, reference numeral 1 is a cylinder inner cylinder having a hydraulic pressure filled therein. A cylinder outer cylinder 2 is arranged outside the cylinder inner cylinder 1, and a reservoir chamber is formed between the cylinder inner cylinder 1 and the cylinder outer cylinder 2, and a gas and a liquid are stored in the reservoir chamber 3. Is filled. A piston rod 5 having a piston 4 at its tip is removably fitted in the cylinder inner cylinder 1. A rod guide 6 supports the piston rod 5 by the rod guide 6 so that the piston rod 5 can reciprocate. This rod guide 6
Is formed by press-molding a metal plate, and has a cylindrical guide portion 6a fitted between the cylinder inner cylinder 1 and the piston rod 5, and a flange shape fitted internally to the cylinder outer cylinder 2. And a supporting portion 6b of. The cylinder 1 can be fitted to the upright tubular portion formed on the support portion 6b. As shown in FIG. 4, chamfered portions 7 are formed on the outer peripheral end of the support portion 6b of the rod guide 6 at five locations in the circumferential direction. Reference numeral 8 denotes a seal, which seals between the cylinder outer cylinder 2 and the piston rod 5. The seal 8 has its mounting base 8a fixed to the end of the cylinder outer cylinder 2 by caulking together with the support 6b of the rod guide 6. As shown in FIGS. 2 to 3, the metal reinforcing ring 9 of the seal 8 is formed with two grooves 10 that are open to the outer peripheral side of the mounting base 8a in the circumferential direction. The groove 10 of the seal 8 forms a passage 11 for communicating the cylinder inner cylinder 1 and the reservoir chamber 3 together with the chamfered portion 7 of the rod guide 6 as shown in detail in FIG.

The mounting base 8a of the seal 8 and the support 6b of the rod guide 6
When the and are fixed to the end of the cylinder outer cylinder 2 by caulking, the mounting base 8a has grooves 10 formed at two locations, and the support portion 6b has chamfered portions 7 formed at five locations. Even if the rod guide 6 is not positioned in the rotation direction, the groove 10
The chamfer 7 and the chamfer 7 always form the passage 11. The passage 11 thus formed is opened and closed by the check lip 12 of the seal 8. That is, the check lip 12 of the seal 8 is in elastic contact with the end surface of the support portion 6b of the rod guide 6 and allows the liquid to flow from the inside of the cylinder 1 into the reservoir chamber 3, but the liquid in the opposite direction and It is designed to block the flow of gas.

According to the above-described structure of the embodiment, when forming the passage 11 that communicates the inside of the cylinder inner cylinder 1 and the reservoir chamber 3, the rod guide 6 only has the chamfered portion 7 formed on the outer peripheral end of the support portion 6b. is there. Therefore, the support portion 6b of the rod guide 6 is
It is possible to support the input load when the vehicle is bound or rebound with sufficient rigidity. Also, the rod guide 6
Deforms following the movement of the piston rod 5 even when a lateral force is applied to the piston rod 5.
Does not generate excessive surface pressure.

In the above embodiments, the grooves 10 are formed in the seal 8 at two places, but the grooves 10 may be formed in four places as shown in FIG. Alternatively, the grooves 10 may be formed in even-numbered places more than that. On the other hand, although the chamfered portions 7 are formed in the rod guide 6 at five equal positions, the chamfered portions 7 may be formed at an odd number of five or more.

Furthermore, the relationship between the numbers of the grooves 10 of the seal 8 and the chamfered portions 7 of the rod guide 6 may be reversed.

Effect of the Invention As described above, according to the present invention, since the groove of the seal and the chamfered portion of the rod guide form a passage that connects the inside of the cylinder in the cylinder and the reservoir chamber, Without lowering the rigidity of the support,
It is possible to support the input load when the vehicle is bound or rebound with sufficient rigidity.

[Brief description of drawings]

FIG. 1 is a sectional view of a hydraulic shock absorber showing an embodiment of the present invention,
FIG. 2 is a front view showing an embodiment of a metal reinforcing ring of a seal,
FIG. 3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 is a front view of a rod guide, FIG. 5 is an enlarged view of a main part of FIG. 1, and FIG. 6 is another embodiment of a metal reinforcing ring of a seal. It is a front view which shows an example. 1 ... cylinder inner cylinder, 2 ... cylinder outer cylinder, 3 ... reservoir chamber, 5 ... piston rod, 6 ... rod guide,
6b …… Supporting part, 7 …… Chamfering part, 8 …… Seal, 8a ……
Mounting base, 10 …… groove, 11 …… passage.

Claims (1)

[Scope of utility model registration request] 1. A cylinder outer cylinder that forms a reservoir chamber between the cylinder inner cylinder, a rod guide made of a metal plate that supports a piston rod so that the piston rod can reciprocate, and a space between the cylinder outer cylinder and the piston rod. In a hydraulic shock absorber comprising a seal for sealing, wherein a support portion of a rod guide and a mounting base portion of the seal are fixed to an end portion of the cylinder outer cylinder, while a groove is formed in the mounting base portion of the seal, A hydraulic shock absorber, characterized in that a chamfered portion is formed at an outer peripheral end of the support portion of the rod guide, and a passage that connects the cylinder in the cylinder and the reservoir chamber is formed by the groove and the chamfered portion.