JPH0517463Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a sub-tank device used in a hydraulic shock absorber.

(Prior Art) Generally, in a hydraulic shock absorber, a cylinder is filled with hydraulic oil, a piston rod is inserted from the outside into the oil chamber filled with the hydraulic oil, and the piston is fixed to the tip of the piston rod. The piston rod moves in and out of the cylinder as the hydraulic shock absorber compresses and expands, but if the entire cylinder is filled with hydraulic oil, an oil lock occurs and the piston rod cannot move in or out.

Therefore, in the past, in order to absorb the volume of hydraulic oil that the piston rod enters, a sub-tank device that communicates with the oil chamber in the cylinder, for example, is provided, and the hydraulic oil that flows into the cylinder when the piston rod enters during the compression stroke is absorbed into the cylinder. Hydraulic oil is sent from the chamber to the sub-tank device, and when the piston rod withdraws during the extension stroke, the hydraulic fluid is returned from the sub-tank device into the cylinder.

Examples of such sub-tank devices include, for example, the one in which the shock absorber cylinder and the sub-tank body are integrally formed by casting, as described in Japanese Utility Model Application No. 49-91908, or
As described in Japanese Patent No. 131489, there is a structure in which the cylinder of the shock absorber and the main body of the sub-tank are formed as separate bodies and the two are connected by a tube.

(Problems to be solved by the invention) However, if the cylinder of the shock absorber and the main body of the sub-tank are integrally formed by casting,
Processing becomes difficult due to complicated molds, and it is not possible to cope with changing models.

Furthermore, connecting the cylinder of the shock absorber and the sub-tank body through a tube increases the number of parts, and moreover, when changing the model, the sub-tank device itself must be changed.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a sub-tank device that is provided with a sub-tank device separate from a damper case, and in which a gas chamber and an oil chamber are formed. a cylindrical holder portion connected to the damper case via a sub-tank joint and a hollow connecting bolt containing a damping force generation mechanism therein, and fitting the sub-tank joint to the outer periphery of the damper case; and a bracket part that is formed integrally with the holder part and extends outward from the holder part, and the connecting bolt is attached to the bracket part, and the tip end of the connecting bolt is screwed to the sub-tank side to attach the sub-tank. is supported, and the oil chamber in the sub-tank and the oil chamber in the damper case are communicated through an oil passage formed in the sub-tank joint and in the connecting bolt.

(Function) Since the sub-tank device is divided into three parts, it is possible to easily change the model by simply changing the sub-tank body, and the processing is easy and the number of parts can be reduced.

(Example) An example of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a partial front cross-sectional view of a shock absorber equipped with a sub-tank device according to the present invention, FIG. 2 is a side cross-sectional view of a main part of the shock absorber, and FIG. 3 is a plan cross-sectional view of the shock absorber.

The hydraulic shock absorber 1 includes a cylinder 3 that is slidably fitted from below onto the outer circumferential surface of a cylinder 2, which is a damper case filled with hydraulic oil, and a stepped portion formed on the outer circumferential surface of the upper end of the cylinder 3. A seal cover 3a is attached, and the upper part of the seal cover 3a is in sliding contact with the outer peripheral surface of the cylinder 2. A cap 4 is attached to the lower end of the cylinder 3, and a bumper rubber 5 is attached to the upper surface of the cap 4.

Then, a piston rod 7 whose lower end is fixed to the bracket 6 is inserted through the cap 4 from below the cylinder 3, and a piston 8 is attached to the upper end of the piston rod 7 so as to be in sliding contact with the inner circumferential surface of the cylinder 2. The inside of the cylinder 2 is defined by the piston 8 into an upper oil chamber S1 and a lower oil chamber S2.

Further, the piston 8 is formed with a compression side oil passage 9 and a growth side oil passage 10, and a valve 11 for closing the compression side oil passage 9 is fitted on the upper surface of the piston 8, and a growth side oil passage is formed on the lower surface. A valve 12 is installed to close the valve 10. Further, a cylinder cap 13 is fitted to the inner circumferential surface of the lower end of the cylinder 2, a rod guide 14 is fitted to the upper side of the cylinder cap 13, and the inner circumferential surface of the rod guide 14 is in sliding contact with the outer circumferential surface of the piston rod 7. An oil seal 15 is fitted.

Furthermore, a spring seat 16 is fitted to the upper end of the cylinder 2, a spring seat 17 is fitted to the lower end of the cylinder 3, and a suspension spring 18 is interposed between these spring seats 16 and 17. Further, a spring load adjustment mechanism 19 is provided below the spring seat 17 to adjust the spring load by moving the spring seat 17 up and down.

Further, the upper end of the cylinder 2 is closed with a cap 20, and an oil hole 21 is formed in the side of the upper end. A sub-tank device 22 is attached to the upper end of this cylinder 2.

This sub-tank device 22 consists of three parts: a sub-tank joint 23 attached to the cylinder 2 as a damper case, a connecting bolt unit 24, and a sub-tank body 25 connected to the sub-tank joint 23 via this connecting bolt unit 24. .

The sub-tank joint 23 includes a holder 26 fitted to the outer peripheral surface of the cylinder 2 and a sub-tank body 2.
An annular oil groove 28 is formed along the inner peripheral surface of the holder 26.
An oil hole 29 is formed in the bracket 27 to communicate the annular oil groove 28 with the connecting bolt unit 24. Then, the annular oil groove 28 of the holder 26
Align the oil hole 21 of the cylinder 2 with the annular oil groove 28.
O-rings 30 are fitted to the upper and lower ends of the cylinder 2, and a holder 26 is fitted to the outer peripheral surface of the cylinder 2.
It is fixed with a set screw 31 at a required position in a direction perpendicular to the axis of the.

The connecting bolt unit 24 consists of a hollow bolt 33 fitted into the bracket 27 of the sub-tank joint 23 and a valve mechanism 34 built into the hollow bolt 33. An oil hole 36 that communicates with the oil hole 29 of the sub-tank joint 23 is formed in the hollow portion 35 on the side of the hollow bolt 33 . The valve mechanism 34 has a low-speed passage 38 formed in the center of the valve holder 37, and a needle 41 formed at the tip of the adjuster 40 faces the low-speed passage 38. forming a flow path 42;
A valve 43 is biased by a spring 44 and inserted in this high-speed flow path 42 . This valve 43
When the hydraulic oil flows from the cylinder 2 side to the sub-tank body 25, the high-speed passage 42 is closed, and when the hydraulic oil returns from the sub-tank body 25 into the cylinder 2, the high-speed passage 42 is opened.

The sub-tank body 25 is connected to the connecting bolt unit 2
The sub-tank 45 is fitted to the rear part of the sub-tank end 44 which is screwed onto the outer periphery of the hollow bolt 33 of 4, and the end of the bladder 47 is fitted into the groove 46 formed on the outer periphery of the rear end of the sub-tank end 44 to complete the sub-tank. The oil chamber S3 of the sub-tank 47 defined by this bladder 47 is held tightly between the inner circumferential surface of the sub-tank 45 and
Hydraulic oil is filled in the chamber S4, and high pressure gas is filled in the other gas chamber S4.

With the above configuration, the sub tank device 22
To assemble, fit the bolt 33 of the connecting bolt unit 24 with the valve mechanism 34 installed into the bracket 27 of the sub-tank joint 23, and then attach the sub-tank end 44 of the sub-tank body 25 to the bolt 33 of the connecting bolt unit 24. Screw on. Then, the holder 26 of the sub-tank joint 23 is attached to the shock absorber 1 by fitting and fixing it to the cylinder 2 of the shock absorber 1.

During the compression stroke of the shock absorber 1, the cylinder 2 moves downward relative to the piston 8 along the inner circumferential surface of the cylinder 3, and the capacity of the oil chamber inside the cylinder 2 decreases.
A portion of the hydraulic oil in the upper oil chamber S1 flows through the oil hole 21 of the cylinder 2 and the annular oil groove 2 of the sub-tank joint 23.
8 and the oil hole 29, between the oil hole 36 of the connecting bolt unit 24 and the needle 41 and the low speed flow path 38, and through the low speed flow path 38 to the sub tank body 25.
The oil flows into the oil chamber S3.

When the compression stroke shifts from this compression state to the extension stroke, the cylinder 2 moves along the inner peripheral surface of the cylindrical body 3 to the piston 8.
Since the capacity of the oil chamber in the cylinder 2 increases, the hydraulic oil in the oil chamber S3 of the sub-tank body 25 flows into the high-speed passage 4 of the connecting bolt unit 24.
2, the check valve 43 is opened, and the hydraulic oil flows through the high-speed passage 42, the low-speed passage 38, the oil hole 36, the oil hole 29 and annular oil groove 28 of the sub-tank joint 23, and the oil hole 21 of the cylinder 2. through the cylinder 2.

In the above embodiment, the connecting bolt unit 24, that is, the sub-tank body 25 is connected to the bracket 27 of the sub-tank joint 23.
As shown in FIG. 4, the connecting bolt unit 24 is attached to the bracket 27 of the sub-tank joint 23 in the axial direction of the cylinder 2, and the sub-tank body 25 is attached to the cylinder 2. It can also be installed parallel to the

(Effect of the invention) As explained above, according to the invention, the sub-tank device is connected to the sub-tank joint that is attached to the damper case, the connecting bolt unit that is fitted into the bracket of this sub-tank joint, and the connecting bolt unit that connects the sub-tank device to the damper case. Since it is divided into three parts, the sub-tank body is connected to the sub-tank joint, it is possible to easily change the shock absorber model by simply changing the sub-tank body, and since the sub-tank device is separate from the shock absorber cylinder, it is easy to process. Since it is attached directly to the cylinder, there is no need for parts such as tubes, and the number of parts can be reduced.Furthermore, the attachment angle of the sub-tank body can be changed. Furthermore, since the holder portion of the sub-tank joint that supports the sub-tank is fitted to the outer periphery of the damper case, the attachment area of the holder portion to the damper case is increased, and the holder portion can be securely attached to the damper case.
Furthermore, since the oil chamber in the sub-tank and the oil chamber in the damper case are communicated through the oil passage formed in the sub-tank joint and the connecting bolt, there is no need for a separate member to connect the oil chambers, reducing the number of parts. This makes it possible to reduce the amount of carbon dioxide and facilitate manufacturing.
Further, since the sub-tank is supported by threading the connecting bolt into the sub-tank, there is no need to form a threaded part in the sub-tank joint, and the manufacturing of the sub-tank joint becomes easier.

[Brief explanation of the drawing]

Fig. 1 is a partial front sectional view of a shock absorber equipped with a sub-tank device according to the present invention, Fig. 2 is a side sectional view of main parts of the buffer, Fig. 3 is a plan sectional view of the buffer, and Fig. 4 is a cross-sectional view of a main part of the buffer.
The figure is a partially front sectional view showing another embodiment of the present invention. In the drawings, 1 is a shock absorber, 2 is a cylinder, 3 is a cylindrical body, 7 is a piston rod, 8 is a piston, 22
is a sub-tank device, 23 is a sub-tank joint, 24 is a connecting bolt unit, 25 is a sub-tank body, 26 is a holder, 27 is a bracket, 33
is a hollow bolt, 34 is a valve mechanism, and 47 is a bladder.

Claims (1)

[Scope of utility model registration request] In a sub-tank device which is equipped with a sub-tank device separate from a damper case and has a gas chamber and an oil chamber formed in the sub-tank, the sub-tank is connected to the sub-tank through a sub-tank joint and a hollow connecting bolt having a damping force generation mechanism built therein. a cylindrical holder part connected to the damper case and fitting the sub-tank joint to the outer periphery of the damper case; a bracket part formed integrally with the holder part and extending outward from the holder part; The connecting bolt is attached to the bracket part, and the tip side of the connecting bolt is screwed to the sub-tank side to support the sub-tank, and an oil passage formed in the sub-tank joint and the connecting bolt is used to connect the inside of the sub-tank. A sub-tank device characterized in that an oil chamber in the damper case communicates with an oil chamber in the damper case.