JPH0224985Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hydraulic shock absorber. This kind of conventional hydraulic shock absorber has a cylinder 1 as shown in FIGS. 1 to 3.
A piston rod 3 is slidably inserted into the cylinder 1 via a piston 2, and two upper and lower oil chambers 4 and 5 are defined within the cylinder 1 by the piston 2.

Three growth-side orifice ports 6 and three compression-side orifice ports 7 are bored in the piston 2 in the axial direction, and a growth-side leaf valve 8 is opened and closed via a projection 7 at the lower mouth end of the growth-side orifice port 6. Similarly, a pressure side leaf valve 10 is freely disposed at the upper mouth end of the pressure side orifice port 7 via a projection 9.
is arranged so that it can be opened and closed freely.

The small diameter portion of the base end of the piston rod 3 includes, from above, a spacer 11 that determines the support diameter of the leaf valve 10, a pressure side leaf valve 10, a piston 2, a growth side leaf valve 8, a spacer 12, and a spacer 12 that regulates the deflection of the leaf valve 8. A stopper 13 is inserted, and a nut 14 is screwed onto the lower end to hold the assembly on the piston rod 3.

When the piston 3 moves to the left in an extension operation, the pressure oil in the upper oil chamber 4 pushes open the leaf valve 8 from the port 6 and is guided to the lower oil chamber, and at this time, an expansion-side damping force is generated due to the deflection of the leaf valve 8. The amount of oil corresponding to the protruding volume of the piston rod 3 is introduced into the lower oil chamber 5 from a base valve (not shown) and compensated for. When the piston rod 3 moves to the right during pressure side operation, the pressure oil in the lower oil chamber 5 pushes open the pressure side leaf valve 10 with a weak set load through the other port 7 and is guided to the upper oil chamber 4. The volume of oil is discharged from the base valve to the tank outside, and the action of the base valve generates a damping force on the pressure side.

For example, the setting of the above-mentioned expansion side damping force is determined by the orifice port 6, the number of leaf valves 8, the plate thickness, the outer diameter, and the outer diameter of the spacer 12. Therefore, in order to cope with the high damping force, it would be sufficient to increase the number of leaf valves 8, but this would be uneconomical.

On the other hand, even if an attempt is made to change the damping force by using the pressure receiving area for the leaf valves 8, 10, the leaf valves 8, 10 are provided at all the mouth ends of the orifice ports 6, 7, and the mouth end opening chambers 15 of each port 6, 7 are ,1
Since the opening area of 6 is constant, the pressure-receiving area is always constant, and to use a piston with a different pressure-receiving area, it is necessary to use a piston with a different size of opening chambers 15 and 16 each time. It is necessary to prepare a large number of main bodies.

Therefore, the purpose of this invention is to provide only one type of piston body, which can be used in common with several types of hydraulic shock absorbers with different damping forces, and to reduce the number of leaf valves, plate thickness, outer diameter, and support diameter of the spacer. Therefore, it is an object of the present invention to provide a hydraulic shock absorber in which the magnitude of damping force can be controlled and the pressure receiving area of a leaf valve can also be controlled in various ways.

In order to achieve the above object, the structure of the present invention is that a piston rod is slidably inserted into a cylinder via a piston, and the piston has two oil chambers, upper and lower, divided into upper and lower oil chambers. In a hydraulic shock absorber in which a communicating orifice port is bored and a leaf valve is provided at the mouth end of the orifice port so as to be openable and closable, a plurality of opening chambers with different opening cross-sectional areas are formed on the end surface of the main body of the piston, Similarly, the piston body is characterized in that an orifice port communicating with one or more of the opening chambers is selectively oriented in the axial direction.

An embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

As in FIG. 1, a piston rod 3 is slidably inserted into the cylinder 1 via a piston 2. Inside the cylinder 1, two oil chambers 4 and 5 are defined, upper and lower, by the piston 2. One or more expansion side orifice ports 26 and compression side orifice ports 27 are bored in the axial direction, and a growth side leaf valve 28 and a compression side leaf valve 30 are connected to the orifice ports through protrusions 17 and 18 on both end surfaces of the piston 2. The oil in the upper oil chamber 4 pushes open the leaf valve 28 from the orifice port 26 and is introduced into the lower oil chamber 5 when the leaf valve 28 is expanded. A side damping force is generated, and in the compression operation, the piston 2 moves to the right, and the hydraulic oil in the lower oil chamber 5 pushes open the leaf valve 30 above the other orifice port 27 and flows out into the upper oil chamber 4. The oil in the tank is discharged into the tank through the base valve at the bottom, and at this time, a compression side damping force is generated by the action of the base valve and the leaf valve 30.

By the way, there is a protrusion 17 on the lower end surface of the main body of the piston 2.
A plurality of opening chambers 2 with different opening cross-sectional areas divided by
6a, 26b...26n are formed, and a plurality of opening chambers 27a, 27b...2 having different opening cross-sectional areas are similarly partitioned by projections 18 on the upper end surface of the piston 2.
7n are formed, and these opening chambers 26a, 26b...
...26n, 27a, 27b...27n, orifice port 26,
27 is formed.

For example, as shown in FIG.
Opening chamber 2 with a larger opening cross-sectional area than e
6b, 26d, and 26f are formed alternately every other space, and an extension side orifice port 26 facing only the opening chambers 26a and 26d is bored. Opening chamber 26
The positions of a...26n may be equally divided as shown in FIG. 5, but may also be separated. Each opening chamber 26a...
... 26n is provided with an extension side leaf valve 28 via a protrusion 17 at the mouth end thereof so as to be openable and closable.

The orifice port 26 has open chambers 26a and 26d.
Although each opening chamber 26a...
...26f, may be formed on only one, or may be formed in plurality, and may be formed selectively each time to obtain a desired damping force.

In this case, if the orifice port 26 is formed in all the opening chambers, the pressure receiving area for the leaf valve 28 will be maximized, and the opening chambers 26a, 26 with small cross-sectional areas
When the orifice port 26 is bored in only one of the ports 26c and 26e, the pressure receiving area becomes the minimum.

If the number of leaf valves, plate thickness, outer diameter, etc. are the same, the smaller the pressure receiving area, the higher the damping force can be obtained.
The combination of pressure receiving areas is determined by the orifice bored in one of the open chambers, and FIG. 5 shows one large and one small open chamber selected.

Similarly, as shown in FIG. 6, the upper end surface of the piston 2 also has a plurality of opening chambers 27a, 27b... with different opening areas.
...27f is formed, and these opening chambers 27a...
A pressure side leaf valve 30 is disposed at the mouth end of the opening chamber 27f via a protrusion 18 so as to be openable and closable.
A compression side orifice port 27 is formed at 27d, and there is a gap between each valve body, and the upper end of the expansion side orifice port 26 is opened from this gap.

The size and position of the opening chambers 27a...27f, the position and number of orifice ports 27, etc. are the same as in the case of FIG.

According to the above structure, for example, according to the structure shown in FIG. 5, during the extension operation, the hydraulic oil in the upper oil chamber 4 flows out into the lower oil chamber 5 through the two orifice ports 26, 26. orifice port 26,
The pressure oil flowing out from 26 into the opening chambers 26a, 26d flows through the valve bodies 28b, 2 facing the opening chambers 26a, 26d.
8b is pushed open, and a rebound damping force is generated due to the deflection of the valve bodies 28b, 28b. Moreover, the magnitude of the damping force at this time depends on the number of valve bodies 28b, the plate thickness, and the outer diameter.
In addition to the support diameter of the spacer 12, there are two opening chambers 26a,
It is determined by the sum of the pressure-receiving areas of the valve body 26d and the valve body 28b. Therefore, if it is desired to change the damping force, this can be achieved by closing one orifice port of the opening chambers 26a, 26d, or by drilling an orifice opposite the other opening chamber in addition to the two orifice ports. Ru.

In addition, during compression operation, in the case shown in FIG.
Since it is formed only in 27d, the opening chamber 27
It is determined by the size of the pressure receiving area with respect to the valve body of the leaf valve 30 of a and 27d.

As described above, the hydraulic shock absorber of the present invention has the following unique effects.

In addition to the conventional damping force specification changing means, a pressure receiving area selection means is added, making damping force setting extremely advantageous.

By selecting the pressure receiving area, the number of leaf valves, plate thickness, etc. can be minimized.

Furthermore, according to the piston incorporated in the hydraulic shock absorber of the present invention, the pressure receiving area can be changed each time by drilling or closing an orifice port in one piston. It can be commonly used for hydraulic shock absorbers with different types of damping, and is advantageous in terms of parts management and cost.

[Brief explanation of the drawing]

Figure 1 is a partially longitudinal front view of a conventional hydraulic shock absorber.
Figure 2 is a side view taken along line B-B in Figure 1, and Figure 3 is a side view of Figure 1.
4 is a partially vertical front view of a hydraulic shock absorber according to an embodiment of the present invention, FIG. 5 is a side view taken along line C-C in FIG. 4, and FIG. D- in Figure 4
It is a D line side view. 1... Cylinder, 2... Piston, 3... Piston rod, 4, 5... Oil chamber, 26, 27... Orifice port, 26a, 26b... 26n, 2
7a, 27b...27n...opening chamber, 28,30
...Leaf valve.

Claims (1)

[Claims for Utility Model Registration] (1) A piston rod is slidably inserted into a cylinder via a piston, the piston divides the cylinder into two upper and lower oil chambers, and the piston communicates with the two oil chambers. Drill the orifice port and
In a hydraulic shock absorber in which a leaf valve is provided at the mouth end of the orifice port so that it can be opened and closed, a plurality of opening chambers with different opening cross-sectional areas are formed on the end surface of the piston body, and the opening chambers are formed on the piston body. A hydraulic shock absorber characterized in that an orifice port communicating with one or more of the above is selectively oriented in the axial direction. (2) The hydraulic shock absorber according to claim 1 of the utility model registration, in which an opening chamber having a larger cross-sectional area is equally distributed among three opening chambers having the same cross-sectional area. (3) The hydraulic shock absorber according to claim 1, wherein the open chamber and the leaf valve are provided on both end faces of the piston main body.