JPS63270934A - Damping force regulator for hydraulic shock absorber - Google Patents

Abstract

PURPOSE:To conduct the multistep regulation of damping force which is close to a stepless regulation by providing at a rotary valve a cutout which opens in turn to the transverse passages of a piston rod as the rotary valve itself rotates. CONSTITUTION:An oil passage 17 consisting of two transverse passages 12, 13 and a longitudinal passage 14 is provided at a piston rod 3, and a transverse passage 11 connecting an upper part oil chamber 4 with transverse passages 12, 13 is formed at a valve presser 10. A cutout 26 formed at a rotary valve 15 which is rotatably inserted in the longitudinal passage 14, is so designed that is opens in turn to transverse passages 12, 13 as the rotary valve 15 rotates. Accordingly, the multistep regulation of damping force is conducted by rotating the rotary valve 15 from the outside through a control rod 27 and regulating an opening area due to the lap of the cutout 26 and transverse passages 12, 13.

Description

[Detailed description of the invention] [Industry 1. [Field of Application] The present invention relates to a hydraulic shock absorber that is installed between the vehicle body and axle of a heavy vehicle to suspend the vehicle body and attenuate vibrations from the road surface. The present invention relates to a damping force adjustment device for a device.

[Conventional technology]

As a conventional hydraulic shock absorber of this kind, one shown in FIG. 9, for example, has been developed.

This has a cylinder 1 and a piston rod 3 movably inserted into the cylinder 1 via a piston 2. The piston 2 partitions the cylinder 1 into two upper and lower oil chambers 4 and 5.

The piston 2 has an extension port 6 that communicates the two oil chambers 4 and 5.
A pressure port 7 is provided at the lower end of the extension port 6, and an extension side valve 8 is provided at the lower end of the extension port 6 so as to be openable and closable, and a compression side valve 9 is provided at the upper end of the pressure boat 7 so as to be openable and closable.

The piston rod 3 and the pulp presser 10 have two oil chambers 4,
11. A rotary valve 15 that forms an oil passage 17 consisting of L2, 13 and a vertical passage 14, and has a plurality of orifices a, b---n in this oil passage 17.
A is inserted rotatably. A check valve mechanism 18 facing an oil passage 17 is provided in a piston nut 16 screwed onto the piston rod 3 so as to be openable and closable.

In the low piston speed range of extension operation, the hydraulic oil in the upper oil chamber 4 is connected to the selected orifice a, b----n,
The oil flows into the lower oil chamber 5 through the oil passage 17 and the orifice provided in the check valve mechanism 18, and a rebound damping force is generated according to the opening area of the selected orifice.

[Problem that the invention seeks to solve]

In the above hydraulic shock absorber, by rotating the rotary valve 15a by external operation, desired orifices a, b---
n can be selected and a damping force corresponding to the selected orifice can be obtained.
There is a problem that it cannot be determined and it is not possible to make nearly stepless multi-stage adjustments.

If the number of horizontal passages and orifices in the piston rod is increased, the number of damping force adjustment devices will increase accordingly, but forming a large number of horizontal passages in the piston rod will reduce the strength of the piston rod, making it difficult to process. Similarly, drilling a large number of small holes in a rotary valve also has limitations in terms of processing, and there is a limit to the adjustment device.

Furthermore, providing a large number of lateral passages in the axial direction of the piston rod complicates the structure and increases the basic length of the piston rod and cylinder.

Furthermore, it is difficult to align the horizontal passage of the piston rod with the orifice of the low-pressure valve, resulting in a problem that accurate damping force adjustment may not be achieved.

Therefore, the present invention provides a damping force adjustment device for a hydraulic shock absorber that is capable of nearly stepless adjustment of the damping force in multiple stages, does not reduce the strength of the piston rod, is easy to process, and is easy to align. The goal is to provide the following.

[Means for solving problems]

In order to achieve the above object, the present invention is characterized in that the rotary valve is provided with a notch that sequentially opens into the lateral passage of the piston rod as the rotary valve itself rotates.

[For production]

When the rotary valve is rotated, the notches communicate with the horizontal passages one by one, and a damping force corresponding to the total opening area of the communicating horizontal passages is generated.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on FIGS. 1 to 8.

1 to 3 and 7 show a hydraulic shock absorber according to an embodiment of the present invention, which is the same as the prior art shown in FIG. 9 except for the structure of the rotary valve.

A piston rod 3 is movably inserted into the cylinder 1 via a piston 2, and the piston 2 defines two upper and lower oil chambers 4 and 5 within the cylinder 1.

An outer cylinder 19 is provided on the outside of the cylinder 1 and arranged concentrically therewith, and a reservoir 20 is defined between the cylinder 1 and the outer cylinder 19.

The piston rod 3 is connected to the cylinder 1, the outer cylinder, and the cylinder 1.
It passes through a bearing and a seal member provided on the upper part of 9 and is connected to the vehicle body side.

A suspension spring 23 is interposed between a spring seat 21 screwed onto the outer periphery of the outer cylinder 19 so as to be vertically movable and a spring seat 22 provided on the upper part of the piston rod 3.

The piston rod 3 includes a valve holder 10, a spacer 25, a pressure side leaf valve 9, a piston 2, and a rebound side relief valve 8a.
The expansion side main valve 8b and the spring 24 are inserted in series, and these members are held by a piston nut 16 screwed into the lower part of the piston rod 3.

The piston 2 has an extension port 6 that communicates the two oil chambers 4.5.
An expansion side valve 8 consisting of an expansion side leaf valve 8a and an expansion side main valve 8b is provided at the lower mouth end of the expansion boat 6 so as to be openable and closable. A pressure valve 9 is provided on the pressure side so as to be openable and closable.

The piston rod 3 is provided with an oil passage 17 consisting of two horizontal passages 12 and 13 and a vertical passage 14.
A horizontal passage 11 is formed in the upper oil chamber 4 to communicate with horizontal passages 12 and 13.

A check valve mechanism 18 facing the oil passage 17 is provided in the piston nut 16 so as to be openable and closable.

A rotary valve 15 is rotatably inserted into the vertical passage 14 at a position facing the horizontal passages 12 and 13, and a notch 26 formed in the rotary valve 15 opens the horizontal passage 12° as the rotary valve 15 rotates. 13 and are opened sequentially.

The notch 26 is one of the two horizontal passages 12.13,
Or, when the valve is fully opened or partially opened, a damping force is generated according to the opening area. Therefore, rotary valve 15
is rotated from the outside via the control rod 27, and the damping force can be adjusted in multiple stages by adjusting the opening area due to the overlap between the notch 26 and the horizontal passage 12.13.

Assuming that the notch 26 opens to the horizontal passage 12.13 and an arbitrary size, the hydraulic oil in the upper oil chamber 4 flows from the horizontal passage 11 to the horizontal passage 12.13 to the notch 26 in the low piston speed range of the expansion side operation. -Vertical passage 14-Flows into the lower oil chamber 5 through the orifice of the check valve mechanism 18, and a damping force is generated due to the opening area of the notch 26.

In the middle and high speed range of the piston, the expansion boat 6 to the expansion side valve 8
When the oil is opened, it also flows into the lower oil chamber 5, and a combined damping force with the expansion valve 8 is generated.

On the other hand, during compression operation, the hydraulic oil in the lower oil chamber 5 lifts the valve of the check valve mechanism 18, and the vertical passage 14-notch 2
6 - Horizontal passages 12, 13 - Upper oil chamber 4 via horizontal passage 11
In the middle and high speed range of the piston, the pressure boat 7 opens the pressure leaf valve 9 and also flows out into the upper oil chamber 4. Oil corresponding to the volume of the intrusion of the piston rod 3 flows out into the reservoir 20 via the base valve at the bottom of the cylinder 1. Notch 2
When 6 and lateral passages 12 and 13 are fully closed, hydraulic oil does not flow from oil passage F, resulting in a hard damping force.

The above operation is substantially the same as that of the prior art, but in the present invention, the shape of the notch 26 and the position of the horizontal passages 12 and 13 have been devised so that the damping force can be adjusted in nearly stepless multiple stages. are doing.

That is, as shown in FIGS. 2 and 3, the rotary valve 1
5, a first opening 26a with a large opening area and a second opening 26b with a small opening area corresponding to the horizontal passages 12 and 13 are formed in two stages, and one opening 26
a is opened and closed to the horizontal passage 12, and the other opening 26b is opened and closed to the horizontal passage 13.

The first stage opening 26a is opened over a circumferential angle with a center angle of 120 degrees, the second stage opening 26b is opened over a circumferential angle with a center angle of 60 degrees, and the first stage opening 26a is opened over a circumferential angle with a center angle of 60 degrees. The distance from the edge of the opening 26b to the center of the horizontal passage 12 is set to be displaced by 30 degrees, and the distance from the edge of the second opening 26b to the other horizontal passage 13 is set to be displaced by 90 degrees. ing.

As shown in the exploded view in Figure 3, the horizontal passages 12 and 13 are cut out 2.
6 and the notch 26 does not open to any of the horizontal passages 12 and 13, hydraulic oil does not flow from the oil passage 17, and at this time, the hard flow is caused by only the expansion side valve 8 and the compression side leaf valve 9. A damping force is generated.

Next, when the rotary valve 15 is rotated from the state shown in FIG. 3, the first stage opening 26a gradually wraps around the horizontal passage 12 and opens. Therefore, by adjusting the amount of rotation of the rotary valve 15, the amount of overlap with the horizontal passage 12 and the opening area are adjusted, and a damping force corresponding to the opening amount of the horizontal passage 12 can be obtained. Okay, in other words, rotary valve 15.
The second horizontal passage 13 is in the notch 2 in the range where the
6, the first lateral passage 12 is adjusted from fully closed to fully open.

Next, in the range where the rotary valve 15 is rotated from 90 degrees to 180 degrees, the horizontal passage 12 of 7!41 is fully opened to the first stage opening 26a, and then the second horizontal passage 13 is fully opened to the second stage opening 26b. It gradually wraps and opens.

Therefore, as shown in Figure 3, the hardest condition is when the two horizontal passages 12.13 are fully open, and the two horizontal passages 12.1
3 is fully opened to each opening 26a, 26b, it is the softest state, and when each lateral passage 12.13 opens little by little, it is an intermediate damping force, and the opening of each lateral passage 12.13 is the softest state. By adjusting the amount, the intermediate damping force can be adjusted to different levels.

According to experiments, 17 levels of adjustment were possible by rotating the rotary valve 15 by 7.5 degrees.

Figure 8 shows the damping force adjustment distribution when adjusted in 17 stages.The horizontal axis is the number of adjustment stages, and the vertical axis is the damping force, when the piston speed is 0. The in/s time balance characteristic is shown by graph P1, the compression characteristic is shown by Pl,
Same (P2 at speed of 0.3 m/s, P2.0.6
At m/5(7) speed, characteristics of P3 and P3 were obtained.

FIG. 4 shows another embodiment of the invention, which has a particular inner diameter of the transverse passage.

The diameter of the side passage 12 is made smaller, the diameter of the other side passage 13 is made larger, and the shape of the notch 26 is the same as in the embodiment shown in FIG.

In this case, there is an advantage that the opening area can be changed constantly, damping force can be changed at equal intervals, and there can be many variations.

FIG. 5 shows another embodiment of the invention, in which the number of transverse passages and the number of stages of notches are three.

That is, there are horizontal passages 12 and 13 on the piston rond side.

13a are formed on the same straight line, and each side passage 12.13
, 13a, the notch 26 has three openings 28a, 26b having different degrees of opening in the circumferential direction.

26c is provided in three stages. In this case, the number of switching stages can be increased by increasing the number of horizontal passages 13a and openings 26c. It is possible to further increase the number of transverse passages and the number of notches as long as problems in processing and strength are acceptable.

FIG. 6 shows still another embodiment of the present invention, in which the lateral passages are provided not in the same straight line but at positions displaced in the circumferential direction at arbitrary center angles, and in which no step is provided in the notch. be.

The lateral passages 12, 13 are provided at positions offset by 0 minutes in the direction of rotation, and the cutouts 26 are simply formed into rectangular cutouts.

In this case, the distance 611 from the edge of the notch 26 to the center of the horizontal passage 12 and the distance 2 from the edge of the notch 26 to the center of the other horizontal passage 13 are the same as the displacement angle θ. When the rotary valve 15 is rotated, there is a delay of an angle θ until the horizontal passage 13 opens into the notch 26, so the effect is the same as that of providing a step in the notch 26 as shown in FIG.

Furthermore, this embodiment has the advantage that the notch 26 for the rotary valve 15 can be easily formed.

Incidentally, it is also possible to modify the embodiment shown in FIG. 6 and to make the inner diameters of the respective lateral passages different or to increase the number thereof.

〔Effect of the invention〕

According to the present invention, there is a first-order effect.

-As the rotary valve rotates, the notches open into the side passages one after another, allowing almost stepless multi-stage damping force adjustment in proportion to the amount of rotation of the rotary valve.

■Since there is no need to provide many horizontal passages in the piston rod, the strength of the piston rod can be maintained, and since the number of horizontal passages is small, the length in the axial direction can be shortened, and there is no need to increase the basic length of the cylinder.

Q) It is sufficient to form a single notch with a large opening area for the rotary valve, eliminating the need for multiple holes and improving workability.

■Since the area of the notch is large, it is easy to align the pair of side passages, and the operability of adjusting the damping force to 5 g is improved.

4. Brief description of aspects Fig. 1 is a partially enlarged sectional view of a hydraulic shock absorber according to an embodiment of the present invention, Fig. 2 is a front view of a rotary valve according to an embodiment of the present invention, and Fig. wS3 to Fig. FIG. 6 is a schematic developed view of each embodiment showing the shape and positional relationship of the horizontal passage and the notch, FIG. 7 is a partially cutaway overall front view of the hydraulic shock absorber incorporating the rotary valve of FIG. 1, FIG. 8 is a graph showing the damping force adjustment distribution when the first hydraulic shock absorber is used, and FIG. 9 is a partially enlarged sectional view of the conventional hydraulic shock absorber.

l...Cylinder, 2...Piston, 3...Piston rond, 4, 5-...Oil chamber, 12,13. L3a-
Horizontal passage, 14... Vertical passage, 17... Oil passage, 15.
...Rotary valve, 26...notch.

Figure 5 Collection 6 illustration N7 diagram Figure 8 ]・6m/,)

Claims (3)

[Claims] (1) A piston rod is movably inserted into the cylinder via a piston, and the piston partitions two oil chambers within the cylinder, and the two oil chambers consist of a horizontal passage and a vertical passage provided in the piston rod. In a hydraulic shock absorber that communicates through an oil passage, and a rotary valve is rotatably inserted into the oil passage to adjust the opening area of the oil passage, the rotary valve is connected to the rotation of the rotary valve itself. 1. A damping force adjustment device for a hydraulic shock absorber, characterized in that a notch is provided which opens correspondingly to the horizontal passage of the piston rod. (2) The hydraulic shock absorber according to claim 1, wherein the piston rod has a plurality of horizontal holes arranged on the same straight line, and the notch of the rotary valve has a number of steps corresponding to the number of horizontal passages. damping force adjustment device. (3) Damping force adjustment of the hydraulic shock absorber according to claim 1, wherein a plurality of horizontal passages are provided on the piston rod at displaced positions, and cutouts without steps are provided on the rotary valve corresponding to the horizontal passages. Device.