JPH0754899A - Damping force regulating type hydraulic buffer - Google Patents

Abstract

PURPOSE:To generate and regulate damping force of a valve characteristic, in a hydraulic buffer provided with a damping force regulating valve on the side surface part of a cylinder. CONSTITUTION:A piston 20 connected to a piston rod 21 is fit-mounted in a cylinder 15. A disk valve mechanism 33 is provided in the valve housing 19 of the cylinder 15, and a damping force regulating valve 39 is provided on the side surface part of the cylinder 15. A cylinder upper chamber 15a and a cylinder bottom chamber 15c are communicated with each other by a communicating pipe 38 through a damping force regulating valve 39 and a disk valve mechanism 33. The cylinder chamber 15c is communicated with a cylinder bottom chamber 15b through an oil liquid passage 32, and communicated with a reservoir chamber 38 through a base valve mechanism 23. Oil liquid flows in the communicating pipe 33 in accompanying with sliding of the piston 20 so as to generate damping force of a valve characteristic by the disk valve mechanism 33, and also it is possible to regulate the valve mechanism by the passing area of the damping force regulating value 39. Since the disk valve mechanism 3 is provided in the cylinder 15, the damping force regulating valve 39 is not enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force adjustable hydraulic shock absorber mounted on a suspension system of a vehicle such as an automobile.

[0002]

2. Description of the Related Art In a hydraulic shock absorber mounted on a suspension system of a vehicle such as an automobile, a damping force can be appropriately adjusted in order to improve ride comfort and steering stability in accordance with road surface conditions, running conditions and the like. There is a damping force adjustable hydraulic shock absorber.

Generally, a damping force adjusting type hydraulic shock absorber has a cylinder in which a piston rod is slidably fitted in a cylinder in which an oil liquid is sealed, and two chambers in the cylinder defined by the piston are formed. Is provided with a communication passage for communicating with each other, and a damping force adjusting valve is further provided in this communication passage. The damping force adjusting valve changes the passage area of the communication passage, and changes the flow resistance acting on the oil liquid flowing in the communication passage as the piston slides, whereby the damping force characteristic can be adjusted.

Further, in the damping force adjusting type hydraulic shock absorber, a damping force adjusting valve is arranged on the side surface of the cylinder in order to facilitate the switching operation of the damping force characteristics in the state of being mounted on the vehicle. is there. An example of a conventional damping force adjusting hydraulic shock absorber of this type will be described below with reference to FIG.

As shown in FIG. 2, the damping force adjusting type hydraulic shock absorber 1 has a double cylinder structure in which an outer cylinder 3 is provided outside a cylinder 2, and a double cylinder structure is provided between the cylinder 2 and the outer cylinder 3. A reservoir chamber 3a is formed in the.

A piston 4 is slidably fitted in the cylinder 2, and the piston 4 allows the cylinder 2 to slide.
The inside is divided into two chambers, a cylinder upper chamber 2a and a cylinder lower chamber 2b. One end side of a piston rod 5 is connected to the piston 4, and the other end side of the piston rod 5 is inserted into a rod guide 6 and an oil seal 7 attached to the end portions of the cylinder 2 and the outer cylinder 3 to be inserted into the cylinder. It has been extended to the outside of 2. At the lower end of the cylinder 2, a base valve mechanism 8 that defines a cylinder lower chamber 2b and a reservoir chamber 3a is provided. The cylinder 2 is filled with oil liquid, and the reservoir chamber 3a is filled with oil liquid and gas.

The piston 4 is provided with a communication passage 9 for communicating the upper cylinder chamber 2a with the lower cylinder chamber 2b, and the base valve mechanism 8 has a communication passage 10 for communicating the lower cylinder chamber 2b with the reservoir chamber 3a. The communication passages 9 and 10 are provided with a damping force generating mechanism including an orifice for generating an appropriate damping force, a disc valve, and the like.
Further, one end of the communication passage 11 is connected to the cylinder upper chamber 2a, and the other end of the communication passage 11 is connected to the reservoir chamber 3a via a damping force adjusting valve 12 provided on the side surface of the cylinder 2. Has been done.

Then, the passage area (orifice area) of the communication passage 11 is changed by the rotation of the shutter 13 of the damping force adjusting valve 12, and the flow resistance acting on the oil liquid flowing in the communication passage 11 due to the sliding of the piston 4 is changed. By changing it, the damping force characteristic can be adjusted.

[0009]

However, in the conventional damping force adjusting type hydraulic shock absorber 1 shown in FIG. 2, the damping force characteristic is adjusted only by changing the orifice area of the communication passage 11 by the damping force adjusting valve 12. Therefore, there is a problem that the adjustment range of the damping force becomes narrow. Damping force control valve
The valve characteristic can be obtained by incorporating a disc valve or the like into the valve 12, but in such a case, there is a problem that the damping force adjusting valve 12 becomes large and the mounting space becomes large. Further, it is very difficult to secure a space for further incorporating a disc valve or the like in a device having a built-in damping force switching actuator.

The present invention has been made in view of the above points, in which the damping force adjusting valve is arranged on the side surface of the cylinder,
Another object of the present invention is to provide a damping force adjustable hydraulic shock absorber capable of widening the adjustment range of damping force characteristics.

[0011]

In order to solve the above-mentioned problems, a damping force adjusting hydraulic shock absorber of the present invention is provided with a cylinder in which an oil liquid is sealed and a slidable fit in the cylinder. A piston defining the inside of the cylinder into two chambers, a piston rod having one end connected to the piston and the other end extending to the outside through one chamber in the cylinder, and the other chamber in the cylinder And a reservoir chamber in which a gas and an oil liquid are sealed, which communicates with each other via a base valve, a communication passage which is provided outside the cylinder and communicates two chambers in the cylinder, and a communication passage which is provided on a side surface of the cylinder. A damping force adjusting valve for adjusting the passage area of the communication passage, and a disc valve mechanism provided in the other chamber in the cylinder for controlling the flow of oil liquid generated between the communication passage and the other chamber in the cylinder. Be equipped with It is characterized in.

[0012]

With this configuration, the circulation of the oil liquid in the communication passage due to the sliding of the piston is controlled by the disc valve mechanism, so that the damping force of the valve characteristic can be generated and the damping force can be generated. The damping force characteristic of the valve characteristic can be adjusted by changing the passage area of the communication passage by the adjusting valve. Further, since the disc valve mechanism is provided inside the cylinder, there is no need for a space for disposing the disc valve mechanism outside the cylinder.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, the damping force adjusting type hydraulic shock absorber 14 has a double cylinder structure in which an outer cylinder 16 is provided on the outer side of a cylinder 15, and between the cylinder 15 and the outer cylinder 16. A reservoir chamber 16a is formed in the. The cylinder 15 has a structure in which an upper cylinder 17 and a lower cylinder 18 are connected by a bottomed tubular valve housing 19.

A piston 20 is slidably fitted in an upper cylinder 17 of the cylinder 15, and the inside of the cylinder 15 is fitted into the cylinder upper chamber 15a and the cylinder lower chamber 15 by the piston 20.
It is defined in b. In addition, the valve housing 19 allows the cylinder bottom chamber 15b and the cylinder bottom chamber in the lower cylinder 18 to
15c is defined. One end side of a piston rod 21 is connected to the piston 20 by a nut 22, and the other end side of the piston rod 21 is attached to the end portions of the cylinder 15 and the outer cylinder 16 as in the conventional example shown in FIG. A rod guide (not shown) and an oil seal (not shown) are inserted and extended to the outside of the cylinder 15. At the lower end of the lower cylinder 18, a base valve mechanism 23 that defines a cylinder bottom chamber 15c and a reservoir chamber 16a is provided. And, oil liquid is sealed in the cylinder 15,
Oil liquid and gas are enclosed in the reservoir chamber 16a.

The piston 20 is provided with an extension-side oil liquid passage 24 and a compression-side oil liquid passage 25 which connect the cylinder upper chamber 15a and the cylinder lower chamber 15b. And piston 20
At the end on the cylinder lower chamber 15b side of the disk valve that generates damping force by allowing only oil liquid to flow from the cylinder upper chamber 15a side of the extension side oil liquid passage 24 to the cylinder lower chamber 15b side.
26 is provided, and at the end on the cylinder upper chamber 15a side,
From the cylinder lower chamber 15b side of the compression side passage 25 to the cylinder upper chamber 15
A disc valve 27 is provided which allows only the flow of the oil liquid to the a side to generate a damping force.

The base valve mechanism 23 includes a cylinder bottom chamber 15
An expansion-side passage 28 and a contraction-side passage 29 are provided to connect the c and the reservoir chamber 16a. Further, the check valve 30 that allows only the flow of the oil liquid from the reservoir chamber 16a side of the extension side passage 28 to the cylinder bottom chamber 15c side, and the oil from the cylinder bottom chamber 15c side of the compression side passage 29 to the reservoir chamber 16a side A disc valve 31 is provided that allows only the flow of the liquid with an appropriate flow resistance.

On the side wall of the valve housing 19, there is an oil liquid passage 32 for connecting the cylinder lower chamber 15b and the cylinder bottom chamber 15c.
Is provided. A disc valve mechanism 33 is provided at the opening of the valve housing 19, and the disc valve mechanism 33 defines a valve chamber 19a in the valve housing 19.

The disc valve mechanism 33 includes a cylinder bottom chamber.
An extension-side passage 34 and a contraction-side passage 35 are provided to connect 15c and the valve chamber 19a. In addition, the disc valve 36 that generates the damping force by allowing only the oil liquid to flow from the valve chamber 19a side of the extension side passage 34 to the cylinder bottom chamber 15c side.
And an orifice 36a for constantly communicating the valve chamber 19a with the cylinder bottom chamber 15c, and the cylinder bottom chamber 15c of the compression side passage 35.
A check valve 37 that allows only the flow of the oil liquid from the side to the valve chamber 19a side is provided. The valve opening pressure of the disc valve 36 is set lower than the valve opening pressure of the disc valve 26 of the piston 20.

One end of a communication pipe 38 is connected to the upper end of the cylinder upper chamber 15a as a communication passage for communicating the cylinder upper chamber 15a and the cylinder lower chamber 15b.
Is inserted between the cylinder 15 and the outer cylinder 16 and extended downward, and the other end thereof is communicated with the valve chamber 19a via a damping force adjusting valve 39 provided on the side surface of the lower portion of the cylinder 15. .

The damping force adjusting valve 39 is provided in the bottom portion of the valve case 40 in which the bottomed tubular valve case 40 is inserted and fixed in the side surface portion of the outer cylinder 16 with the bottom portion facing the cylinder 15 side. The passage 41 is connected to the side surface of the valve housing 19, and the end of the communication pipe 38 is connected to the side surface of the valve case 40. On the bottom side inside the valve case 40,
A cylindrical guide 42 is fitted, and a passage 41 of the valve case 40 connects the inside of the guide 42 and the valve chamber 19a. Further, the side wall of the guide 42 has a communication pipe 38
Is provided with a port 43 communicating with.

A shutter member 44 is inserted in the valve case 40, and a cylindrical shutter portion 45 formed at one end of the shutter member 44 is rotatably fitted in a guide 42. The side wall of the shutter portion 45 has a port 43 of the guide 42.
Facing each other, a plurality of orifices 46 having different diameters are arranged in parallel along the circumferential direction. Then, by rotating the shutter portion 45 and selectively aligning one of the plurality of orifices 46 with the port 43, the communication passage area between the communication pipe 38 and the passage 41 can be adjusted.

A substantially cylindrical plug 47 is screwed into the opening of the valve case 40 to rotatably support the shutter member 44. An end portion of the shutter member 44 is inserted into a plug 47 and extended to the outside, and a dial 48 is attached to the tip end portion thereof with a screw 49. Then, by rotating the dial 48 from the outside, the shutter member 44 is rotated. Further, a spring 50 and a latch ball 51 are provided in a large-diameter portion in the middle of the shutter member 44, and the plurality of latch balls 51 provided on the inner peripheral portion of the valve case 40 are provided by the elastic force of the spring 50. By engaging the groove 52, the shutter member 44 can be held in a predetermined rotational position in which one of the orifices 46 and the port 43 are aligned.

The operation of the present embodiment configured as above will be described below.

During the extension stroke of the piston rod 21, when the piston speed is in the low / medium speed range, the oil liquid on the cylinder upper chamber 15a side along with the sliding of the piston 20 causes the communication pipe 38, the port 43,
Flow through the orifice 46 of the shutter portion 45, the passage 41, the valve chamber 19a and the extension side passage 34 of the disc valve mechanism 33 to the cylinder bottom chamber 15c. At this time, the disc valve mechanism
The disc valve 36 and the orifice 36a of 33 generate a damping force having an orifice characteristic or a valve characteristic depending on the piston speed. Further, the damping force characteristic can be adjusted by rotating the dial 48 to adjust the area of the orifice 46 of the shutter portion 45. It should be noted that a part of the oil liquid in the cylinder bottom chamber 15c flows to the cylinder lower chamber 15b through the oil liquid passage 32 of the valve housing 19, and the oil liquid corresponding to the piston rod 21 withdrawing from the cylinder 15 is The expansion of the gas causes the reservoir chamber 16a to move to the base valve mechanism 23.
Is replenished in the cylinder bottom chamber 15c through the extension side passage 28.

When the piston speed is in the high speed region, the flow resistance of the oil liquid becomes large, so that the pressure in the cylinder upper chamber 15a rises and the disc valve 26 of the piston 20 opens, so that the oil liquid in the cylinder upper chamber 15a is released. A damping force having a valve characteristic is generated by flowing directly to the cylinder lower chamber 15b through the expansion oil passage 24.

During the compression stroke of the piston rod 21, if the piston speed is in the medium to low speed range, the oil liquid on the cylinder lower chamber 15b side due to the sliding of the piston 20 is transferred to the oil liquid passage 32 of the valve housing 19 and the cylinder bottom chamber 15c. , The contraction side oil liquid passage 35 of the disc valve mechanism 33, the valve chamber 19a, the passage 41, the shutter portion 45
Through the orifice 46, the port 43, and the communication pipe 38 of the above, to the cylinder upper chamber 15a. At this time, the damping force of the orifice characteristic is generated according to the area of the orifice 46 of the shutter portion 45, and the damping force characteristic can be adjusted by rotating the dial 48. The amount of oil that the piston rod 21 has entered the cylinder 15 passes from the cylinder bottom chamber 15c through the contraction side passage 29 of the base valve mechanism 23 to the reservoir chamber.
16a, and the gas in the reservoir chamber 16a is compressed.

When the piston speed is in the high speed range, the flow resistance of the oil liquid increases, so the pressure in the cylinder lower chamber 15b rises and the disc valve 27 of the piston 20 opens, and the oil liquid in the cylinder lower chamber 15b contracts. A damping force having a valve characteristic is generated by flowing directly to the cylinder upper chamber 15a through the oil liquid passage 25.

As described above, the damping force having the valve characteristic can be generated by the disc valve mechanism 33, and the damping force characteristic can be adjusted by rotating the dial 48 to change the area of the orifice 46. it can. Further, since the disc valve mechanism 33 is arranged inside the cylinder 15 and is not built in the damping force adjusting valve 39, the valve characteristic is generated without increasing the size of the damping force adjusting valve 39,
It can also be adjusted.

In this embodiment, the damping force adjusting valve 39 is
The communication passage area is adjusted by selecting a plurality of orifices 46 provided in the shutter portion 45, but not limited to this, for example, by changing the alignment state of the guide port and the shutter opening portion. The communication passage area may be continuously adjusted, or in addition, the communication passage area may be adjusted.

Further, the base valve mechanism 23 has a disc valve 31 for exerting a flow resistance on the flow of the oil liquid from the cylinder bottom chamber 15c to the reservoir chamber 16a. However, the present invention is not limited to this. The flow resistance may be applied, and any material can be used as long as it can exert an appropriate flow resistance.

Further, in the present embodiment, the manual operation of the damping force adjusting valve has been described.
It can also be applied to a device in which the damping force control valve is operated by an actuator.

[0033]

As described in detail above, the damping force adjusting hydraulic shock absorber of the present invention allows the flow of the oil liquid in the communication passage that connects the two chambers in the cylinder defined by the piston to the outside of the cylinder. Since the disc valve mechanism controls the damping force of the valve characteristic, the damping force of the valve characteristic can be changed by changing the passage area of the communication passage by the damping force adjusting valve provided on the side surface of the cylinder. The characteristics can be adjusted. Further, since the disc valve mechanism is provided inside the cylinder, there is no need for a space for disposing the disc valve mechanism outside the cylinder.
As a result, it is possible to generate and adjust the damping force of the valve characteristic without increasing the size of the damping force adjusting valve on the side surface of the cylinder, and it is possible to widen the adjustment range of the damping force characteristic. Produce an effect.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part of an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a conventional damping force adjusting hydraulic shock absorber.

[Explanation of symbols]

 14 Damping force adjustable hydraulic shock absorber 15 Cylinder 15a Cylinder upper chamber 15b Cylinder lower chamber 16a Reservoir chamber 20 Piston 21 Piston rod 23 Base valve mechanism 33 Disc valve mechanism 38 Communication pipe (communication passage) 39 Damping force adjustment valve

Claims (1)

[Claims] 1. A cylinder in which an oil liquid is sealed, a piston slidably fitted in the cylinder to define two chambers in the cylinder, one end of which is connected to the piston and the other end of which is the cylinder. A piston rod extended to the outside through one chamber inside, a reservoir chamber in which gas and oil liquid are sealed, which communicates with the other chamber inside the cylinder via a base valve, and the outside of the cylinder A communication passage provided in the cylinder for communicating the two chambers in the cylinder, a damping force adjusting valve provided in a side surface of the cylinder for adjusting the passage area of the communication passage, and provided in the other chamber in the cylinder. A damping force adjusting hydraulic shock absorber, comprising: a disc valve mechanism that controls a flow of an oil liquid generated between the communication passage and the other chamber in the cylinder.