JP2000009170A - Hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent damage to a leg portion of a leaf spring and improve durability and reliability. A retainer (16) is provided with a leg accommodation hole (16B), and when a valve plate (13) of a check valve is opened against a leaf spring (14), a leg (14C) of the leaf spring (14) is accommodated in the retainer (16). It is configured to be housed in the hole 16B. This allows
When the valve plate 13 is opened, the leg 14C of the leaf spring 14 can be released into the leg receiving hole 16B of the retainer 16, so that the leg 14C can be prevented from being damaged by an excessive force, and the leaf spring 14 can be prevented from being damaged. Can be improved in durability.

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 mounted on a vehicle such as an automobile and suitable for damping vibration during running.

[0002]

2. Description of the Related Art In general, a suspension device or the like mounted on a vehicle has a piston inside a cylinder filled with an oil liquid in order to reduce vibrations and impacts applied to the vehicle body due to unevenness of a road surface during running of the vehicle. A hydraulic shock absorber is provided which gives resistance to the flowing oil liquid by being displaced in the direction and generates a damping force.

[0003] This type of hydraulic shock absorber includes a shock absorber main body in which an oil liquid is sealed, an oil boundary defining member for defining the inside of the shock absorber main body into two oil chambers, and an oil boundary. An oil passage provided in the defining member and communicating the two oil chambers; a valve plate for a check valve for opening and closing the oil passage so that the oil liquid flows only in one direction in the oil passage; A leaf spring provided to overlap the plate and biasing the valve plate in a valve closing direction by a leg extending radially outward; and a valve spring provided facing the valve plate with the leaf spring interposed therebetween. It is roughly constituted by a retainer for regulating the valve opening of the plate.

[0004] Further, as an oil boundary defining member, a piston or a bottom portion of a cylinder which is axially displaceably inserted into a cylinder provided in the shock absorber main body and defines two oil chambers in the cylinder. And a bottom valve that defines the inside of the cylinder and the reservoir chamber, and a piston rod that extends and contracts from the cylinder is attached to the piston.

Here, the case where the piston is used as an oil boundary defining member will be described. The piston is provided with the above-mentioned oil passage penetrating in the axial direction, and one end face is provided on the opening side of the oil passage. , The above-described valve plate, leaf spring, and retainer are sequentially arranged. Further, the leaf spring is formed of a thin plate having a spring property, whereby the urging force of the leg against the valve plate is set to be very small.

[0006] The valve plate and the leaf spring close the oil passage when either the extension or contraction of the piston rod is displaced. At this time, a resistance to the oil liquid is provided by a disk valve provided on the other end surface of the piston. Given. Also,
At the time of the other displacement of the piston rod, the oil passage is easily opened, and at this time, a resistance is given to the oil liquid by a disk valve provided in the bottom valve.

Further, when the valve plate is opened, the valve plate is brought into contact with the retainer, thereby regulating the valve opening of the valve plate to an appropriate size, and the valve plate is damaged by excessive deformation. Is prevented.

[0008]

In the above-described conventional hydraulic shock absorber, a leaf spring is disposed so as to overlap a valve plate, and the valve plate is biased in the valve closing direction by the legs of the leaf spring. Therefore, when the valve plate is opened, the leg of the leaf spring is sandwiched between the valve plate and the retainer.
For this reason, an excessive force may act on the leg portion of the leaf spring, and the leg portion may be damaged, resulting in a problem that durability and reliability are reduced.

Particularly, in recent years, in order to increase the response of the damping force during operation, the valve plate and the leaf spring are formed to be very thin, so that there is a problem that the durability of the leaf spring is reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a hydraulic shock absorber capable of preventing damage to a leg portion of a leaf spring and improving durability and reliability. To provide equipment.

[0011]

SUMMARY OF THE INVENTION A hydraulic shock absorber according to the present invention comprises a shock absorber main body in which an oil liquid is sealed, and an oil boundary defining member for defining the inside of the shock absorber main body into two oil chambers. An oil passage provided in the oil boundary defining member and communicating the two oil chambers; a valve plate for opening and closing the oil passage so that the oil liquid flows only in one direction through the oil passage; A leaf spring for biasing the valve plate in the valve closing direction by a leg extending radially outward; and a valve spring provided to face the valve plate with the leaf spring interposed therebetween. And a retainer that regulates the valve opening degree.

Then, in order to solve the above-mentioned problem,
A feature of the structure adopted in the first aspect of the invention is that the retainer is provided with a leg receiving hole into which the leg of the leaf spring enters when the valve plate is opened against the leaf spring.

With this configuration, when the valve plate is opened against the leaf spring by the oil flowing through the oil passage, the valve plate comes into contact with the retainer, and the valve opening is regulated at this position. You. At this time, since the leg of the leaf spring is accommodated in the leg accommodation hole formed in the retainer, it is possible to prevent the leg from being caught and damaged between the valve plate and the retainer.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a hydraulic shock absorber according to an embodiment of the present invention will be described in detail with reference to FIGS.

1 is a cylinder provided in the shock absorber main body C, in which an oil liquid is sealed, and 2 is a piston rod whose base end penetrates into the cylinder 1 and whose distal end projects outside the cylinder 1. The proximal end side of the rod 2 is a small-diameter portion 2A, into which a piston 3, a disc valve 10, a valve plate 13, a leaf spring 14, a retainer 16 and the like are inserted and fixed by a nut 2B. .

Reference numeral 3 denotes a piston which is inserted into the cylinder 1 so as to be displaceable in the axial direction and forms an oil boundary defining member.
The piston 3 is fixed to the base end side of the piston rod 2 via a small diameter portion 2A inserted through the rod insertion hole 3A. Also,
The piston 3 defines the inside of the cylinder 1 into two oil chambers 1A and 1B.

Reference numerals 4 and 4 denote a plurality of extension-side oil passages (only two are shown) formed in the axial direction of the piston 3. Each of the extension-side oil passages 4 is an oil chamber defined in the cylinder 1. 1A and 1B are communicated with each other, and the oil liquid flows from the oil chamber 1B to the oil chamber 1A during the extension stroke of the piston rod 2.

Reference numerals 5 and 5 denote a plurality of reduction-side oil passages (only two are shown) which are located on the outer peripheral side of each extension-side oil passage 4 and are formed in the axial direction of the piston 3. The passage 5 communicates the oil chambers 1A and 1B defined in the cylinder 1.
In the reduction stroke of the piston rod 2, the oil liquid flows from the oil chamber 1A to the oil chamber 1B.

Reference numeral 6 denotes an annular valve seat which is located on the oil chamber 1A side of the piston 3 and is provided on the inner peripheral side of each reduction side oil passage 5.
The annular valve seat 6 has an annular recess 7 formed therein.
Each extension side oil passage 4 is opened.

Reference numeral 8 denotes an annular valve seat located on the oil chamber 1B side of the piston 3 and provided on the outer peripheral side with respect to each extension side oil passage 4.
The annular valve seat 8 has an annular recess 9 formed therein.
Each reduction side oil passage 5 is opened.

Numeral 10 is a disc valve which is provided on the annular valve seat 6 of the piston 3 so as to be detachable and seatable.
Numeral 0 is formed by laminating, for example, disk-shaped thin metal plates having spring properties. An orifice 10A is formed in the thin metal plate located at the lowermost portion of the disc valve 10 so as to always communicate the oil chamber 1A with the annular concave portion 7 (each extension-side oil passage 4). When the piston 3 is slid to the extension side, the disc valve 10 opens each of the extension side oil passages 4.
Through the oil chamber 1B to the oil chamber 1A.

Reference numeral 11 denotes a disk-shaped spacer interposed between the disk valve 10 and the nut 2B. The spacer 11 secures a space for the disk valve 10 to open. Reference numeral 12 denotes a disk-shaped washer provided between the spacer 11 and the nut 2B. The washer 12 regulates the valve opening of the disc valve 10.

Reference numeral 13 denotes a valve plate for a check valve, which is disposed on the end face of the piston 3 located on the side of the oil chamber 1B, and is formed in a disk shape. The valve plate 13 is made of a thin plate having spring properties. As shown in FIG. 2, a movable portion that is located on the inner peripheral side and has a rod insertion hole 13A formed therein and is located on the outer peripheral side of the fixed portion 13B and separates from and seats on the annular valve seat 8 of the piston 3 The fixed portion 13B and the movable valve portion 13C are radially connected to each other by a connecting portion 13D.

Reference numeral 14 denotes a leaf spring provided so as to overlap with the valve plate 13. The leaf spring 14 is formed of a thin plate having a spring property, and as shown in FIG. 3, a fixed portion 14B having a rod insertion hole 14A formed therein. Three leg portions 14 extending radially outward from the fixing portion 14B and arranged at substantially equal intervals in the circumferential direction.
C, 14C, and 14C, and a positioning side 14D that is located between any two of the three legs 14C and protrudes radially outward from the fixed portion 14B. Each leg portion 14C biases the movable valve portion 13C of the valve plate 13 in the valve closing direction, and is bent toward the piston 3 side, and a distal end portion contacts the movable valve portion 13C. Further, the positioning piece 14D is positioned in the positioning hole 1 of the retainer 16.
6C and is bent to the opposite side to the piston 3.

An annular spacer 15 is provided between the leaf spring 14 and the valve plate 13, and the spacer 15 secures a space for the movable valve portion 13C of the valve plate 13 to open. ing.

Reference numeral 16 denotes a retainer provided between the leaf spring 14 and the piston rod 2, and the retainer 16 is formed as a thick circular plate having a rod insertion hole 16A at the center. As shown in FIG. 4, the retainer 16 has three rectangular leg receiving holes 16 located at outer circumferential sides of the rod insertion hole 16A and at substantially equal intervals in the circumferential direction.
B, 16B, and 16B are provided, and each leg accommodation hole 16B is provided.
A rectangular positioning hole 16C is provided between any two of the leg accommodation holes 16B.

The leg receiving hole 16B receives the leg 14C of the leaf spring 14 when the valve plate 13 is opened against the urging force of the leaf spring 14, as shown in FIG. .
The leg accommodation hole 16 </ b> B also serves as an oil hole for smoothly flowing the oil liquid in the oil chamber 1 </ b> B toward each extension-side oil passage 4 during the extension stroke of the piston rod 2. Further, the positioning holes 16C engage with the positioning pieces 14D of the leaf spring 14 to position the legs 14C in the leg housing holes 16B.

Here, the valve plate 13 and the leaf spring 14 constituting the check valve close each of the reduced-side oil passages 5 when the piston rod 2 is extended, and the hydraulic fluid in each of the reduced-side oil passages 5 is closed. When the piston rod 2 is contracted, the respective reduced-side oil passages 5 are opened, so that the oil liquid in the oil chamber 1A through the respective reduced-side oil passages 5 flows to the oil chamber 1B. It allows distribution.

The hydraulic shock absorber according to the present embodiment has the above-described configuration, and its operation will be described below.

First, in the extension stroke of the piston rod 2,
The piston 3 slides and displaces in the direction of arrow A, and the pressure in the oil chamber 1B becomes higher than the pressure in the oil chamber 1A. At this time, since the leaf spring 14 closes each reduction-side oil passage 5, the pressure in the oil chamber 1 </ b> B acts on the disk valve 10 via the extension-side oil passage 4.

Here, when the piston 3 is displaced at a low speed and the pressure in the oil chamber 1B acting on the disc valve 10 is small, the oil liquid in the oil chamber 1B passes through the orifice 10A and flows into the oil chamber 1A. , A small resistance is given by the orifice 10A, and a small damping force is generated at this time.

When the piston 3 is displaced at a high speed and the pressure in the oil chamber 1B acting on the disc valve 10 is large, the oil in the oil chamber 1B opens the disc valve 10 to open the oil chamber 1A. Since the oil flows into the side, a large resistance is given to the oil liquid by the disk valve 10, and at this time, a large damping force is generated.

As described above, during the extension stroke of the piston rod 2, the resistance applied to the oil liquid changes according to the magnitude of the pressure generated in the oil chamber 1B. Can be.

On the other hand, in the reduction stroke of the piston rod 2,
The piston 3 slides and displaces in the direction of arrow B, and the pressure in the oil chamber 1A becomes higher than the pressure in the oil chamber 1B. At this time, the pressure in the oil chamber 1 </ b> A
3 act on the movable valve portion 13C, the movable valve portion 13C opens against the urging force of the leaf spring 14, and the oil liquid in the oil chamber 1A flows through the reduction-side oil passage 5 to the oil chamber 1B side. Flows into. Further, since the spring force of the valve plate 13 and the leaf spring 14 is set to be weak, the oil liquid in the oil chamber 1A flows into the oil chamber 1B without resistance. In the process of reducing the piston rod 2,
A desired damping force is obtained by a damping force generating mechanism (neither is shown) provided in the bottom valve.

The pressure in the oil chamber 1A causes the valve plate 13
When the movable valve portion 13C is opened, as shown in FIG. 5, the movable valve portion 13C contacts the retainer 16, and the valve opening is regulated at this position. At this time, since each leg 14C of the leaf spring 14 urging the movable valve portion 13C of the valve plate 13 in the valve closing direction is accommodated in each leg accommodation hole 16B formed in the retainer 16, An unreasonable force can be prevented from acting on each leg 14C, and damage to each leg 14C can be prevented.

The leaf spring 14 has a positioning piece 14D.
The positioning hole 16C is provided in the retainer 16 and the both are engaged, so that the leaf spring 14 and the retainer 16 can be positioned in the circumferential direction, and each leg 14C is located in the leg accommodation hole 16B. Can be reliably accommodated.

As described above, according to the present embodiment, when the valve plate 13 is opened against the leaf spring 14 by providing the leg receiving hole 16 B in the retainer 16, the leg of the leaf spring 14 Since the portion 14C can be accommodated in the leg accommodation hole 16B, when the valve plate 13 is opened, the leg 14C of the leaf spring 14 can escape into the leg accommodation hole 16B of the retainer 16, and the leg It is possible to prevent an excessive force from acting on 14C. As a result, the leg portion 14C can be prevented from being damaged and the durability of the leaf spring 14 can be improved.
The reliability of the hydraulic shock absorber can be improved.

The positioning piece 14 provided on the leaf spring 14
By engaging D with a positioning hole 16C provided in the retainer 16, the leaf spring 14 and the retainer 16 can be positioned in the circumferential direction, so that each leg 14C is securely received in the leg receiving hole 16B. It is possible to prevent damage to each leg 14C due to displacement.

In the embodiment, the piston rod 2
In the example described above, the pressure in the oil chamber 1B is applied to the disc valve 10 during the extension stroke of the valve chamber 13 and the valve plate 13 is opened during the contraction stroke of the piston rod 2. The present invention is not limited to this, and the mounting relationship between the disc valve 10 and the valve plate 13 or the like may be reversed in the extension stroke and the contraction stroke.

In the embodiment, the piston 3 that defines the interior of the cylinder 1 provided in the shock absorber main body C into two oil chambers 1A and 1B has been described as an example of the oil boundary defining member. Alternatively, the cylinder 1 may be used as an oil boundary defining member.
A bottom valve defining the inside and a reservoir chamber (not shown) may be used.

[0041]

As described in detail above, according to the first aspect of the present invention, since the leg receiving hole into which the leg of the leaf spring enters is provided when the valve plate is opened, the oil passage is provided. When the valve plate is opened against the leaf spring by the flowing oil, the leg of the leaf spring can be accommodated in the leg accommodation hole formed in the retainer, and the leg is located between the valve plate and the retainer. It can be prevented from being damaged by being caught between. Thereby, the durability of the leaf spring can be increased, and the reliability of the hydraulic shock absorber can be improved.

[Brief description of the drawings]

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

FIG. 2 is a plan view showing a valve plate in FIG. 1;

FIG. 3 is a plan view showing a leaf spring in FIG. 1;

FIG. 4 is an arrow IV-IV in FIG. 1 showing a leaf spring, a retainer, and the like.
It is the cross-sectional view seen from the direction.

FIG. 5 is an enlarged longitudinal sectional view of a main part in FIG. 1, showing a state in which a leg of a leaf spring is accommodated in a leg accommodation hole of a retainer.

[Explanation of symbols]

 Reference Signs List 1 cylinder 3 piston (oil boundary defining member) 4 extension side oil passage 5 contraction side oil passage 13 valve plate 14 leaf spring 14C leg 16 retainer 16B leg receiving hole C shock absorber main body

Claims (1)

[Claims] 1. A shock absorber main body having an oil liquid sealed therein,
An oil boundary defining member that defines the interior of the shock absorber main body into two oil chambers; an oil passage provided in the oil boundary defining member and communicating the two oil chambers; A valve plate that opens and closes the oil passage so as to circulate only in the direction, and a leaf spring that is provided so as to overlap the valve plate and urges the valve plate in the valve closing direction by a leg that extends radially outward. And a retainer provided so as to face the valve plate with the leaf spring interposed therebetween, and a retainer for regulating a valve opening of the valve plate. A hydraulic shock absorber comprising a leg receiving hole into which a leg of the leaf spring enters when the valve plate is opened.