JPH01250634A - Hydraulic shock absorber - Google Patents

Abstract

PURPOSE:To aim at the miniaturization of a shock absorber as well as to make its main tenance into facilitation by installing an accumulator in a manifold in having one end situated in an around a damping force generating valve unit installed in the manifold along an outer cylinder. CONSTITUTION:A flow passage 8 being interconnected to a piston lower chamber 41b at a tip of the other end of a rod 4 is installed in the inner part of this rod 4 being attached to a piston 3 fitted in a cylinder free of slide motion and projecting its one end to the outside of the cylinder. Then, a damping force generating valve unit 31 is housed in a manifold attached to the side of a projecting end of the rod 4 out of the cylinder. An accumulator 41 is attached to a manifold base 23 via a valve case 28 in having its end situated in an around this damping force generating valve unit 31 along an outer cylinder 2 whereby each length of the manifold base 23 in the axial direction of the rod 4 and the accumulator 41 becomes shortened. Therefore miniaturization for a hydraulic shock absorber is contrived as a whole and, what is more, its maintenance can be made into facilitation.

Description

[Detailed description of the invention] "Industrial application field" The present invention relates to a hydraulic shock absorber.

``Prior Art'' As is well known, a hydropneumatic shock absorber is installed between the body of an automobile and the axle to adjust the vehicle height and absorb sudden changes in the axle. A suspension (hereinafter abbreviated as suspension) is installed.

As this type of suspension, for example, a suspension as shown in FIG. 3 has been proposed.

This suspension consists of a double cylinder consisting of an inner cylinder I and an outer cylinder 2, which communicate with each other through a communication hole 1a formed in the inner cylinder l. Attach 4,
This rod 4 is the inner cylinder! , a rod guide 5 provided at the top of the outer cylinder 2. Seal member 6. The upper part of the rod 4 (inner cylinder) of a hydraulic shock absorber body (suspension body) 9 is made to penetrate through the lock ring 7 and protrude from the upper part of the outer cylinder 2, and form a passage (through hole) 8 in the center of the rod 4. l, the side of the protruding end of the rod 4 from the outer cylinder 2), attach the manifold 10, and attach the manifold 10 to the
A damping force generating valve unit 12 having a plurality of accumulators 11 located on the sides of the outer circumference of the outer cylinder 2 along the outer cylinder 2 at 0, and having a damping valve in which these accumulators 11 are housed in a manifold 10.
The outer cylinder 2 is attached to the axle (not shown) and the upper end of the rod 4 is attached to the vehicle body. A hydraulic unit (not shown) that supplies pressure oil into the inner cylinder 1 is connected, and the pressure oil from this hydraulic unit is supplied to the inner cylinder 1 of the suspension body 9 and the accumulator 11, and is applied to the vehicle body via the rod 4. is gradually raised, the vehicle height is maintained at a predetermined vehicle height position, and sudden changes in the axle are buffered by the damping force generating valve unit 12, reducing the load on the vehicle body and increasing the height of the vehicle body. When this happens, the pressure oil in the inner cylinder 1 is returned to the hydraulic unit to lower the height of the vehicle body and adjust the vehicle height.

The inside of the inner cylinder 1 is divided by the piston 3 into a piston upper chamber 1b and a piston lower chamber 1c, and a plurality of orifices 3a are formed in the piston 3, and these orifices 3a form a piston upper chamber! b communicates with the piston lower chamber 1c.

Further, the damping force generating valve unit 12 is provided on the side of the rod 4 at approximately the center in the vertical direction of the manifold lO, the accumulator 11 is provided below the damping force generating valve unit 12, and the accumulator 11 is provided at the upper part of the damping force generating valve unit 12. A damping force generating valve is attached to the manifold 10 by screwing the cap 13 together. 14 is the inner cylinder 1. This is a reservoir formed between the outer cylinders 2.

"Problems to be Solved by the Invention" However, in the above-described hydraulic shock absorber, the damping force generating valve unit 12 is provided approximately at the vertical center of the manifold lO, and an accumulator is provided below the damping force generating valve unit 12. 11, and a cap 13 is screwed onto the top of the damping force generating valve unit 12, so that these caps 13. The damping force generating valve unit 12 and the accumulator 11 are connected vertically and become long, occupying a large space in the suspension mounting area, which greatly restricts the installation location of other devices and makes maintenance of these devices difficult. There was a problem.

An object of the present invention is to provide a hydraulic shock absorber that solves the above-mentioned problems of conventional shock absorbers.

"Means for Solving the Problems" The present invention has the following configuration in order to achieve the above object. That is, a flow path communicating with the lower chamber of the piston at the other end of the rod is provided inside a rod that is attached to a piston that is slidably fitted into a cylinder and has one end protruding outside the cylinder. A damping force generating valve unit is housed in a manifold attached to the side of the protruding end of the rod from the rod, and an accumulator is provided in the manifold with one end positioned around the damping force generating valve unit and along the cylinder, The accumulator is configured to communicate with the flow path within the rod via a damping force generating valve unit.

1 action" By placing the accumulator on the manifold with one end located around the damping force generating valve unit and along the outer cylinder, the combined length of the manifold and accumulator in the axial direction of the rod is shortened, thus reducing the size. It takes up less space for installation, greatly reduces restrictions on the installation location of other equipment, and simplifies maintenance.

"Example" An example of the present invention will be described below with reference to FIGS. 1 and 2. Incidentally, in this embodiment, the same parts as those of the previously proposed hydraulic shock absorber shown in FIG.

In this embodiment, a manifold base 23 is attached via a cover 22 to the upper part of a bang rubber 21 that fits into the rod 4 and is provided above the lock ring 7 . As shown in FIG. 2, this manifold base 23 has a horizontally long rectangular shape with rounded ends. The manifold base 23 is located at one end side of the rod 4, that is,
Inner cylinder! , is attached to the side of the protruding end of the rod 4 from the outer cylinder 2 in a tight fit. 24, 24 is O
It's a ring. A branch flow path 25 is formed in the manifold base 23 and extends in a direction perpendicular to the rod 4 and communicates with the through hole 8 of the rod 4. This branch flow path 25
One end is branched from the through hole 8 and communicated with a branch hole 26 formed in the rod 4, and the other end of the branch channel 25 is bent downward in FIG.

At each tip of the end surface (lower surface in FIG. 1) of the manifold base 23 on the side of the vane rubber 21, a cylindrical valve case 28 having a hollow portion 27 is provided, the axial direction of which is parallel to the axial direction of the rod 4. It is attached in a hanging manner.

A plurality of grooves 28a, 28b and steps 28c are formed on the outer periphery of the valve case 28. O ring 2 is placed in the groove 28a.
8d is fitted. In addition, the first valve case 28
The lower end in the figure is thin.

The valve case 28 is fastened to the manifold base 23 by a plurality of bolts 29. The valve cases 28 are sealed by a seal ring 30 interposed therebetween. In addition, in this embodiment, these manifold base 23 and valve case 2
8 forms a manifold.

The hollow part 27 is communicated with the branch flow path 25 of the manifold base 23, and a damping force generating valve unit 31 fitted into the hollow part 27 is installed in the valve case 28 so that the lower end of the valve case 28 in FIG. It is attached by crimping it by bending it.

The damping force generating valve unit 31 has a bolt 32 and a plurality of communication holes 33 formed at an angle with respect to the axial direction, and annular grooves 34° 34 are formed on both end faces, and the bolt 32 is fitted into the center hole. A damping force-generating valve consisting of a plurality of discs is provided between the assembled ring 35 and one end surface of the ring 35 and the head of the bolt 32 so as to fit onto the bolt 32 and cover the annular groove 34. (hereinafter referred to as damping valve)
36, and a damping force generating valve (hereinafter referred to as a damping valve) 37 consisting of a plurality of discs fitted to the bolt 32 and provided so as to cover the annular groove 34 provided on the other end surface of the ring 35.
and a washer 38 to prevent excessive deflection of the damping valve 37.
, the nut 39 screwed onto the bolt 32, and the bolt 32
The retainer 40.40 is fitted into the retainer 40.40 and serves as a fulcrum for the deflection of the damping valve 36.37. A notch (not shown) is formed in the outer periphery of the disk on the ring 35 side among the plurality of disks of each of the damping valves 36, 37.

Further, an accumulator 41 is attached to the manifold base 23 via a valve case 28. This accumulator 41 has a free piston 42 slidably fitted into a cylinder having a bottom. The accumulator 41 is arranged around the damping force generating valve unit 31 at one end (the upper end in FIG. 1) of the accumulator 41.
position and connect this accumulator 41 to the outer cylinder 1.
By caulking a portion of the outer periphery of the valve case 28 facing the groove 28b, the accumulator 41 is fitted into the groove 28b, and the upper end of the accumulator 41 is caulked to the step 28c.

The upper piston chamber 41a of the accumulator 41 is filled with oil, and the lower piston chamber 41b is filled with pressure gas. Note that the accumulator 41 may be attached to the valve case 28 by other means than caulking, as long as its one end is located around the damping force generating valve unit 31.

The outer cylinder 2 is attached to the axle (not shown), and is attached to one end side of the rod 4 (the upper end side in FIG. 1).
is attached to the vehicle body 43 via a mount rubber 44 with a nut 45. Further, a block 46 is attached to one end of the rod 4 (the upper end in FIG. 1) in a fluid-tight manner. Branch holes 47 and 48 are formed in the block 46 and communicate with the through hole 8 of the rod 4.
A hydraulic unit (not shown) is connected to 7°48.

The upper end of the through hole 8 is closed by a plug 49.

Next, the operation of the hydraulic shock absorber (suspension) configured as described above will be explained.

Attach the outer cylinder 2 to the axle (not shown) and attach the upper part of the rod 4 to the vehicle body 43, and connect the branch hole 47.4.
Since the pressure oil supply part and the pressure oil return part of a hydraulic unit (not shown) are connected to 8, the pressure oil from this hydraulic unit is supplied into the cylinder 1 inside the suspension body 9, and is passed through the rod 4. The vehicle body 43 is gradually raised, and the vehicle height is maintained at a predetermined vehicle height position by the action of a control mechanism (not shown) connected to a hydraulic unit. In order to dampen the sudden movement of the axle, the suspension of this embodiment has the piston 3. The rod 4 enters the inner cylinder 1, and part of the oil in the lower piston chamber 1c passes through the orifice 3a and reaches the upper chamber of the piston. At the same time, the remaining oil flows through the through hole 89, the branch hole 26, and the branch flow path 25, and flows into the hollow part 27.
The damping valve 36 is opened to generate a damping force, and the free piston 42 is pushed down, flowing into the piston upper chamber 41a and stored in the accumulator 41.

Further, in the extension process, the rod 4 protrudes from the inner cylinder 1 and the outer cylinder 2, and the pressure oil in the piston upper chamber lb flows into the piston lower chamber Ic through the orifice 3a. At the same time, the free piston 42 rises due to the gas pressure in the lower piston chamber 41b of the accumulator 41, and the oil in the upper piston chamber 41a of the accumulator 41 opens the damping valve 37 to generate a damping force. Hollow part 27
It flows into the piston lower chamber 1c through the branch flow path 251, branch hole 261, and through hole 8.

Further, when the load on the vehicle body 43 decreases and the height of the vehicle body increases, the control mechanism (not shown) returns the pressure oil in the inner cylinder l to the hydraulic unit to lower the height of the vehicle body. adjust.

As described above, according to this embodiment, the accumulator 41 is attached to the manifold base 23 via the valve case 28 with one end positioned around the damping force generating valve unit 31 and along the outer cylinder 2, so that the rod 4
The joint length between the manifold base 23 and the accumulator 41 in the axial direction of the hydraulic shock absorber is shortened, and the entire hydraulic shock absorber is therefore miniaturized, saving space and greatly reducing restrictions on the installation location of other equipment. and facilitate maintenance.

In addition, since the valve case 28 is detachably attached to the manifold base 23 and the accumulator 41 is attached to the valve case 28, the accumulator 41 and the damping force generating valve unit 31 can be replaced freely, and maintenance can be simplified. Not only is it easy, but when the accumulator is integrated with the manifold, the manifold and accumulator must be replaced if they are damaged.In contrast, in this embodiment, the manifold can be used as is and the accumulator 41 Alternatively, since it is only necessary to replace the valve case 28, manufacturing and maintenance costs can be reduced.

Further, since the accumulator 41 of this embodiment is provided with a free piston 42, it has good functionality as an accumulator, and has the same effect as using a normal large-capacity accumulator. Therefore, if the accumulator 41 of this embodiment is used, it can be significantly downsized compared to conventional buffers.

In the above embodiment, the two accumulators 41 are attached to the manifold base 23, but the invention is not limited to this, and the manifold base can be made into a T-shaped plane as shown by the imaginary line in FIG. An accumulator may be attached to each tip of the manifold base.

In this case, two or one of the three accumulators is used, and the flow path to the remaining one or two accumulators can be controlled to open and close, thereby controlling the spring characteristics and damping force characteristics of this accumulator. It can also be used as an accumulator for use.

In the above embodiments, the present invention was applied to a hydro-pneumatic suspension, but the present invention is not limited thereto, and can also be applied to a general hydraulic shock absorber.

[Effect of the Invention J According to the present invention, since the accumulator is provided in the manifold with one end positioned around the damping force generating valve unit provided in the manifold and along the outer cylinder,
The combined length of the manifold and accumulator in the axial direction of the rod can be shortened, resulting in smaller size, less installation space, significantly reducing restrictions on the installation location of other equipment, and reducing maintenance. It can be facilitated.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is an example of the previously proposed hydro-pneumatic suspension. FIG. l...Inner cylinder, la...Communication hole,
lb... Piston upper chamber, Ic... Piston lower chamber, 2... Outer cylinder, 3...
Piston, 4... Rod, 8... Channel (through hole), 14... Reservoir, 23...
... Manifold, 25... Branch flow path, 28.
... Valve case, 31 ... Damping force generation valve unit, 36.37 ... Damping force generation valve (damping valve), 41 ... Accumulator,
42...Free piston.

Claims (1)

[Claims] Inside a rod that is attached to a piston that is slidably fitted into a cylinder and has one end protruding outside the cylinder,
A flow path communicating with the lower piston chamber at the tip of the other end of the rod is provided, and a damping force generating valve unit is accommodated in a manifold attached to the side of the protruding end of the rod from the cylinder. A hydraulic shock absorber, characterized in that an accumulator is provided on the manifold with one end positioned around the manifold along the cylinder, and the accumulator is communicated with a flow path in the rod via the damping force generating valve unit.