JPH0488231A - Hydraulic shock absorber rotary valve - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rotary valve for a hydraulic shock absorber that is optimally adapted to counteract the swiss noise in its inner space.

(Prior art and its problems) Various types of hydraulic shock absorbers that have rotary valves and can adjust the generated damping force have been proposed in the past. Well,
A swiss noise may occur inside the rotary valve.

That is, the hydraulic shock absorber has a piston portion 2 slidably housed in the cylinder 1, which partitions the lot-side oil chamber A and the piston-side oil chamber B in the E-marked cylinder 1. mouth·
The engine side oil chamber A and the piston side oil chamber B are connected to the piston part 2.
is formed so as to communicate with the piston rod 3 connected to the tip thereof via an open bypass path, and - in the bypass path, that is, the piston rod 3 has an open vertical connection. A rotary valve 4 is rotatably housed in the hole 3a and can select whether or not to communicate with the bypass path when the rotary valve 4 is rotated.

The rotary valve 4 is configured to rotate in a predetermined manner when a rotary rod 5 connected to the upper end thereof is rotated, and the rotary rod 5 rotates in a predetermined manner by the rotation of the rotary rod 5 connected to the upper end side of the rotary valve 4. The rotary rod is housed so as to be movable in a through hole 3b formed in the core, and an appropriate actuator is connected to a protruding end externally from the upper end of the piston rod 3, although not shown in the IA. 5 rotational operations are possible.

Therefore, in the above-mentioned conventional hydraulic oil pressure pump, when the rotary valve 4 is used when the piston portion 2 slides within the cylinder l, a part of the hydraulic oil may pass through the bypass path. Therefore, the hydraulic oil flows into the piston portion 2.
For example, the main damping force generated when passing through is adjusted to have a decreasing tendency.

However, at this time, when the hydraulic oil from the rod side oil chamber A flows into the inner space 4b through the pore 4a such as an orifice opened in the rotary valve 4, the inner space!
In 4b, scoop 1. Shusuke may occur.

That is, the #swiss sound is caused by the horizontal hole 3c drilled in the piston rod 3 where the hydraulic oil from the rotary side oil chamber A, which is the high-pressure side that is the outer peripheral side of the rotary valve 4, constitutes a bypass path. The rotary valve 4 is inserted into the rotary valve 4 through a perforated hole 4a so as to face the horizontal hole 3c.
It is generated by rapidly flowing into the inner cavity 4b on the low pressure side, which is the inner peripheral side.

There is also a proposal to suppress the generation of the above-mentioned swiss noise by making the open pores 4a of the rotary valve 4 double-shelled.In this case, the rotary valve 4
Not only is it inconvenient that the so-called effort to open the plurality of pores 4a is increased, but also the inflow of hydraulic oil in the inner space 4b-\ is caused by multiple threads). There is a risk that the middle part will collide with each other, and the thickness of the switch a will become larger.

This invention is based on the above-mentioned circumstances! 7) The purpose of this system is to effectively prevent the occurrence of switch 8 and to have a rotary valve so as to be able to adjust the generated reduced Q force. The purpose of this invention is to provide a rotary valve for a hydraulic shock absorber that is suitable for use in hydraulic shock absorbers.

In order to achieve the above-mentioned object, the structure 4II of the present invention is rotatably housed in a bypass passage opened in a piston rod, and when the piston rod rotates, [2] Hydraulic pressure I formed with pores 41 that enable communication of the foot bypass passage.
In the rotary valve of the s-impact device, the tip of the rotary rod, which is housed in the rotating part inside the axis of the piston rod and connected to the rotary valve, is located in the inner cavity of the rotary valve. , the rotary valve has a perforated pore configured to face the outer circumferential surface of the tip of the rotary rod.

(Function) During the extension stroke when the piston part is removed from the cylinder, the rotary valve is rotated and a hole is formed on the piston rod that forms a hole or a bypass path in the rotary valve. When the hole is aimed, the bypass passage L becomes in communication, and the hydraulic oil from the loft side oil chamber flows into the inner space of the rotary valve.

At this time, the hydraulic oil that suddenly flows into the inner space on the low n: side from the S6 pressure side inlet/ent side oil chamber is present at the tip of the rotary rod that is present in the inner space. Therefore, the rapid flow of hydraulic oil into the inner space collides with the tip of the rotary rod.

As a result, unlike the conventional example, a situation in which the rapid flow of hydraulic oil collides with each other in 1#'V contact does not occur, and swiss noise is not generated.

(Example) Hereinafter, the present invention will be described in detail based on an example shown in UA.

As shown in FIG. 1, the hydraulic shock absorber according to one embodiment of the present invention has basically the same structure as the conventional example described above, and the four parts of the rotary hull, which are the main parts, have a different structure. I think there are some differences.

Therefore, in the following, the same parts of the configuration will be indicated by reference numerals in each figure, and will only be used in the text, and their explanation will be omitted.

Note that the piston portion 2 is provided with a rebound damping valve 2a and a compression damping valve 2b.

When the hydraulic oil from the lot side oil chamber A partitioned by the piston part 2 in the cylinder l flows into the piston side oil chamber B via the expansion side boat 2d which is opened in the piston body 2c, a predetermined expansion occurs. At the same time, the hydraulic oil from the piston side oil chamber B is pumped into the piston body 2C through the pressure side boat 2e.
It is assumed that a predetermined overwhelming damping force is generated when the oil flows into the lot side oil chamber A through the oil chamber A.

Next, the rotary valve 4, which is the main part of this invention, will be briefly explained.

The rotary valve 4 is disposed in a bypass path that enables communication between the lot side oil chamber A and the piston side oil chamber B in the cylinder l, bypassing the piston part 2, or Inside, the piston rod 3 is formed with a vertical hole 3a and a horizontal hole 3c, as in the conventional example described above.

The rotary valve 4 is formed into a cylindrical shape with a head and is rotatably housed in the vertical hole 3a.
A tip portion 5a near the lower end of the rotary rod 5 in the figure is press-fitted into an open mounting hole 4d in the upper end mounting portion 4c, thereby making it possible to connect the rotary valve 4 with the rotary rod 5. .

Further, as shown in FIG. 2, the rotary valve 4 has a pore 4a such as an orifice in the partition wall 4e on the lower end side, and the #pore 4a constitutes the bypass path. It is assumed that it faces the horizontal hole 3c of the piston rod 3.

Further, the rotary valve 4 is set to rotate in a predetermined manner when the rotary rod 5 is rotated, as in the conventional example described above, and the rotary rod 5
It is rotatably housed in a through hole 3b formed in the axial center of the piston rod 3, and an appropriate actuator (not shown) is attached to the protruding end externally from the F end of the piston rod 3. The rotary rod 5 can be rotated by being connected.

The tip portion 5b of the rotary rod 5, which is the lower middle end in the figure, is located in the inner cavity 4b of the rotary valve 4, and the wI wall portion 4e of the rotary valve 4.
The pore 4a drilled in the hole 4a or the tip 5b of the rotary rod 5
It is set so as to face the outer peripheral surface of.

Therefore, in the hydraulic shock absorber formed as described above, the rotary valve 4 is rotated to bring the rotary valve 4 into communication with the open hole 4a or the bypass path, and the piston When the part 2 is withdrawn from the cylinder 1 during the extension stroke, the hydraulic oil from the lot side oil chamber A flows into the inner space 4b of the rotary valve 4 through the pore 4a of the rotary valve 4. Become.

At this time, the hydraulic oil from the rod side oil chamber A, which is the high pressure side, is
Will it suddenly flow into the inner space 4b on the low pressure side?
The tip PJsh of the rotary rod 5 is present in the inner cavity 4b, so that the rapid flow of hydraulic oil into the inner cavity 4b collides with the tip 5b of the rotary rod 5.

As a result, in the inner space 4b, unlike in the conventional example, the rapid flow of hydraulic oil does not directly collide with each other, and no swiss noise is generated.

In the above description, the tip end 5b of the control rod 5, which is present in the inner space 4b of the rotary valve 4, is formed into a rod shape having the same vertical diameter. As shown in , it may be formed in the shape of an inverted truncated cone whose diameter decreases toward the bottom, and in this case, it is also possible to obtain the same effect as described above.

Further, as described above, the pores 4a opened in the rotary valve 4 may be set in a pair on the left and right sides, or alternatively, as in the conventional example described above, the pores 4a may also be set in the vertical direction. It may be set in such a manner that it is arranged in I number.

Furthermore, the control valve 4 described above is a so-called rotary type in which the control valve 4 rotates within the vertical hole 3a bored in the piston rod 3. Of course, the same effect can be obtained even if it is of a so-called slide type that slides vertically within the open vertical hole 3a.

〔Effect of the invention〕

As described above, according to the present invention, the tip end of the rotary rod connected to the rotary valve is present in the inner cavity of the rotary valve rotatably housed in the vertical hole formed in the piston rod. In addition, since the rotary valve is configured such that the open pores are opposed to the outer peripheral surface of the tip of the rotary rod, the occurrence of the swiss noise can be effectively prevented in advance. Of course, due to its configuration, it is sufficient to make the rotary rod slightly longer, so it can be implemented without making major design changes to conventional products, which reduces productivity. There is an advantage in not letting it happen.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical cross-sectional view showing a hydraulic shock absorber according to one embodiment of the present invention, FIG. 2 is a partial enlarged cross-sectional view thereof, and FIG. 3 is a partial enlarged vertical cross-sectional view showing a control valve according to another embodiment. The plan view and FIG. 4 are partial longitudinal sectional views showing a conventional hydraulic shock absorber similar to FIG. 1. (Explanation of symbols) ! ...Cylinder 2...Piston part 3...
Piston rod 3a...Vertical hole 3C...Horizontal hole
4...Rotary valve 4a...Small hole
4b...Inner space 5...Rotary rod 5b
--Tip L...Bypass road agent Patent attorney Izumi Amano Figure 1 Figure 2 C Figure 3

Claims (1)

[Claims] A rotary valve for a hydraulic shock absorber, which is rotatably housed in a bypass passage opened in a piston rod and is formed to have a pore that enables communication with the bypass passage when the piston rod rotates, The tip of the rotary rod, which is rotatably housed inside the axis of the piston rod and connected to the rotary valve, is present in the inner cavity of the rotary valve, and has a pore formed in the rotary valve. A rotary valve for a hydraulic shock absorber, characterized in that the rotary valve is configured to face the outer peripheral surface of the tip of the rotary rod.