JPH02195039A - Hydraulic shock absorber - Google Patents

Abstract

PURPOSE:To enable the optimum damping force characteristic to the set according to a vehicle, by constituting a damping force generating mechanism with large diametered and small diametered disk valves and inside and outside pressurization chambers. CONSTITUTION:When the oil pressure within inside and outside pressurization chambers 28 and 29 ascends as a piston 15 is operated, the outer perimeter side of a large diametered disk valve 25 bends, and the force of damping due to both valve characteristics is generated, and further, when the oil pressure ascends, both of large diametered and small diametered disk valves 25, 26 bend, and a damping force characteristic combining both valve characteristics is obtained. And it is possible to change pressures at which respective disk valves 25, 26 open, and the grades of the valve characteristics, through the change of the rigidity of respective valves 25, 26, and setting is possible so that a high damping force may be obtained at the early stage of an operation when the operation speed of the piston 15 is low. Further, setting, also, is possible so that the damping force may be restrained low at a range in which the operation speed of the piston 15 is a little high, and setting freely a damping force characteristic according to a vehicle can be realized.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a hydraulic shock absorber used in vehicles and the like.

(Prior Art) Conventionally, as shown in FIG. 17, in a hydraulic shock absorber l used in a shell, two pistons are inserted into the cylinder 2 by a piston 3 which is slidably fitted into the cylinder 2. The chambers 4.5 are divided into chambers 4.5, and each chamber 4.5 is communicated with each other through a communication passage 6 formed in the piston 3. Also, on the bottom side, the cylinder 2 and the outer cylinder 7 are partitioned by a partition member 8 to form a chamber 9. are formed, and the chamber 9 and the chamber 5 in the cylinder 2 are communicated through a communication passage 10, and as the piston 3 slides within the cylinder 2, each communication passage 6. l
A damping force generation mechanism tt consisting of a plurality of disc valves and orifice passages controls the flow of oil generated in O.
, tz to generate the damping force.

The hydraulic shock absorber 1 with this configuration has damping force characteristics as shown in FIG. 18, and when the operating speed of the piston 3 is slow, the damping force is generated due to the oil being throttled as it passes through the orifice passage. Quadratic curve characteristics a, b,
When the operating speed of the piston 3 is high, the linear characteristic a 2 * b 2 occurs when the disc valve bends in response to the hydraulic pressure.

(Problems to be Solved by the Invention) In the conventional hydraulic shock absorber 1 described above, the characteristics caused by the orifice passage (orifice characteristics) are quadratic characteristics, and the initial operation of the piston (V + It has a characteristic that a small damping force is generated in the section of 2) and then increases rapidly.

By the way, in order to prevent vehicle body wobbling and improve steering stability during normal driving, a certain amount of large damping force is required at the initial stage of piston operation, but this can be adequately addressed depending on the orifice characteristics described above. Moreover, a large damping force is generated in the section (section v2 shown in FIG. 18) where the characteristics (valve characteristics) produced by the disc valve change after the initial stage of operation.
Vibrations from the wheels are transmitted to the vehicle body, impairing ride comfort.

As described above, the damping force characteristics of the conventional hydraulic shock absorbers described above do not allow the damping force to appropriately correspond to the running of the vehicle, resulting in the problem that optimum handling stability and ride comfort cannot be obtained. Ta.

The present invention has been made in view of the above problems, and its object is to provide a hydraulic shock absorber that can set optimal damping force characteristics depending on the vehicle.

(Means for Solving the Problems) The hydraulic shock absorber of the present invention controls the movement of oil fluid generated in a communication path that communicates between two partitioned chambers by the sliding of a piston in a cylinder. A hydraulic shock absorber having a damping force generating mechanism that generates a damping force, the damping force generating mechanism is stacked on a large diameter disc valve disposed downstream of the communication passage, and the damping force generating mechanism is laminated on the large diameter disc valve, and the damping force generating mechanism is stacked on the large diameter disc valve and a disk valve having a smaller diameter than the large-diameter disk valve; an inner pressurizing chamber that is arranged radially inward on the opposite side of the large-diameter disk valve from the small-diameter disk valve and communicates with the communication passage; disposed on the same side as the inner pressurizing chamber and radially outward from the inner pressurizing chamber, and extending radially outward from the outer periphery of the small diameter disc valve;
and an outer pressurizing chamber that communicates with the communication passage and applies hydraulic pressure to the outer peripheral side of the large-diameter disc valve.

Further, in the above configuration, a set load setting means may be provided to give initial deflection to the small diameter disc valve.

Furthermore, the hydraulic shock absorber of the present invention generates a damping force by controlling the flow of oil produced in a communicating path between two partitioned chambers by sliding a piston in a cylinder. In a hydraulic shock absorber having a mechanism, the damping force generating mechanism is arranged in a disc valve disposed on the downstream side of the communication passage, and a disc valve disposed at different positions in the radial direction of the disc valve, each communicating with the communication passage. an inner pressurizing chamber and an outer pressurizing chamber that apply hydraulic pressure to the disc valve; and a partition wall that partitions between the inner pressurizing chamber and the outer pressurizing chamber on the opposite side of each of the pressurizing chambers of the disc valve. and spring means disposed at corresponding positions to press and bias the disc valve toward the pressurizing chamber.

(Function) According to this configuration, when the piston operates and the hydraulic pressure in each pressurizing chamber increases through the communication passage, the small diameter disc valve or the stacked part will become the part where only the large diameter disc valve exists. Since the valve will not open unless the pressure is greater than that of the large-diameter disc valve, first, the outer circumference of the large-diameter disc valve bends and generates a damping force due to the valve characteristics.Furthermore, as the oil pressure in each pressurizing chamber increases, the large-diameter By flexing both the disc valve and the small-diameter disc valve to generate a damping force based on the valve characteristics, a damping force characteristic that is a combination of the valve characteristics can be obtained.

By changing the rigidity of each disc valve, it is possible to change the pressure at which each disc valve opens and the gradient of the valve characteristics, so high damping force can be obtained at the initial stage of operation when the piston operating speed is low. Furthermore, it can be set to keep the damping force low in a range where the piston operating speed is slightly higher than that, allowing you to freely set the damping force characteristics according to the vehicle. It becomes possible.

In addition, by applying an appropriate initial deflection to the small-diameter disc valve using the set load setting means, it is possible to reduce the rigidity of the small-diameter disc valve without changing the rigidity of the small-diameter disc valve or the number of disc valves used, or even if the rigidity is lowered. The pressure at which the valve opens can be increased.

In addition, if the disc valve is pressed by a spring member,
When the piston operates and the oil pressure in each pressurized chamber increases through the communication path, the disc valve is pressed by the spring member, so the outer circumference first flexes, creating a damping force characteristic of the valve. Further, when the oil pressure in each pressurizing chamber increases, the entire disc valve flexes against the pressing force of the spring member, thereby generating a damping force of the valve characteristics. This provides a damping force characteristic that is a combination of the damping forces of the valve characteristics.

By appropriately changing the rigidity of the disc valve and the spring constant of the spring member, the pressure at which the disc valve opens and the gradient of the valve characteristics can be changed, so the damping force characteristics can be freely set according to the vehicle. It becomes possible to do so.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a first embodiment, and its configuration will be explained.

A piston 15 attached to a piston rod 14 is slidably fitted into the cylinder 13 via a piston ring 16, and the piston 15 connects the inside of the cylinder 13 to an upper cylinder chamber 17 and a lower cylinder chamber 18. It is sectioned. The piston 15 is formed with an extension passage 19 and a contraction passage 20 parallel to the axis of the piston rod 14, which communicate the upper cylinder chamber 17 and the lower cylinder chamber 18. One side of the extension passageway 19 opens into an annular groove 21 formed on the upper end surface of the piston 15, and the other side opens into an annular groove 22 formed on the lower end surface of the piston 15. One side of the contraction side advancement passage 20 opens into the cylinder lower chamber 18, and the other side opens into an annular groove 23 formed in the upper end surface of the piston 15 in a radially outward direction from the annular groove 21.

An extension-side damping force generation mechanism 24 is provided below the piston 15 on the downstream side of the extension-side advancement path 19, and generates a damping force during the extension stroke of the piston 15. Next, this configuration will be described.

A large diameter disc valve 25 is provided on the lower end surface of the piston 15.
A plurality of small-diameter disk valves 26 are stacked and provided on the opposite side of the large-diameter disk valve 25 from the extension path 19.

The annular groove 22, which is formed on the lower end surface of the piston 15 and in which the extension passageway 19 opens, is located radially inward from the outer periphery of the small-diameter disc valve 26, and this annular groove 11i1! 22, an annular groove 2 that extends radially outward from the outer periphery of the small-diameter disc valve 26 and is located inward from the outer periphery of the large-diameter disc valve 25.
7 is formed. The annular groove 22 and the large-diameter disk valve 25 constitute an inner pressurizing chamber 28, and the annular groove 27 and the large-diameter disk valve 25 constitute an outer pressurizing chamber 29. In addition, each pressurization chamber 28, 29 is a re-pressurization chamber 28.
．． A plurality of throttle passages 30 provided in a partition wall 30 between 29
communicated by a.

The small-diameter disc valve 26 has a hydraulic pressure F when the pressure inside the outer pressurizing chamber 29 increases and the outer peripheral side of the large-diameter disc valve 25 bends, and a larger hydraulic pressure F (F, <F2) is the inner pressurizing chamber. The rigidity is set so that the valve opens when the valve is applied from 28. Note that the rigidity of each disc valve 25, 26 may be set only by the plate thickness and material, or as shown in the figure, a plurality of holes 31 are formed in the circumferential direction of the large-diameter disc valve 25. The rigidity of the outer peripheral side of the disc valve 25 may be reduced.

On the other hand, a check valve mechanism 32 is provided on the upper end surface of the piston 15, and this will be explained.

The annular groove 2 formed on the upper end surface of the piston 15
A disc valve 33 is seated so as to close the piston 1.23, and the disc valve 33 is urged against the piston 15 by a leaf spring 35 attached via a retainer 34. Further, the disc valve 33 includes a piston 15.
An annular groove 1 that opens an extension side advancement path 19 formed in
A plurality of holes 36 are formed corresponding to the holes 9 to communicate the cylinder upper chamber 17 and the extension side advancement path 19. Note that 37 in the figure is a washer for regulating the amount of deflection of the disc valve 33.

By configuring the check valve mechanism 32 in this way, when the oil pressure in the eccentric transmission passage 20 increases during the contraction stroke, the disc valve 33 bends against the biasing force of the plate spring 35, causing the cylinder lower chamber to rise. Oil flows from 18 to the cylinder upper chamber 17.

Note that during the compression stroke, a damping force is generated by a compression side damping force generation mechanism provided on the bottom side (not shown) of the hydraulic shock absorber.

Further, the check valve mechanism 32, the piston 15, and the extension side damping force generation mechanism 24 are connected to the small diameter portion 3 of the piston rod 14.
8 and screwed into the end of the small diameter portion 38
is tightened and fixed.

The operation of the hydraulic shock absorber with the above configuration is shown in Figures 1 and 2.
This will be explained using figures.

First, when the piston 15 is pulled up via the piston rod 14 during the extension stroke, the pressure in the cylinder upper chamber 17 increases and oil flows in the extension bias passage 19.

At this time, the oil flows from the extension side advancement path 19 to the inner pressurizing chamber 28.
further flows into the outer pressurizing chamber 2 through the throttle passage 30a.
9 to increase the pressure in each pressurizing chamber 28,29. Then, when the oil pressure in the outer pressurizing chamber 29 rises to F, the outer peripheral side of the large-diameter disc valve 25 is bent and opened to generate a damping force shown in C1i in FIG. When the speed increases, the flow from the inner pressurizing chamber 28 to the outer pressurizing chamber 29 is throttled by the throttle passage 30a, and when the oil pressure in the inner pressurizing chamber 28 rises to F2, the large diameter disc valve 25 and The entire small-diameter disc valve 26 is bent and opened, and a damping force shown by C2&l is generated.

In this damping force characteristic, the values of pressure F and pressure F2 and the slopes of line C1 and C211 can be easily adjusted by changing the initial deflection amount and rigidity of each disc valve 25, 2fi.

Furthermore, if the opening area of the throttle passage 30a that communicates the pressurizing chambers 28 and 29 is changed to a smaller size, the orifice characteristics can be taken into account in addition to the above-mentioned valve characteristics.
A damping force characteristic as shown by the line (two-dot chain line) can be obtained.

Furthermore, by providing a notch on the outer circumferential side of the large-diameter disc valve 25 to form an orifice passage (not shown) that communicates the extension side advancement passage 19 and the lower cylinder 13 chamber, E in FIG. It is also possible to obtain a damping force characteristic that takes into account the Oriswiss characteristic as shown by the line (broken line).

By making various adjustments in this way, the piston 15
The damping force can be set high even in a low operating speed range, and the damping force characteristics can be set to be optimal for the vehicle, resulting in good handling stability and ride comfort.

Next, other embodiments will be described.

The second embodiment shown in FIGS. 3 and 4 differs from the first embodiment only in the shape of the outer pressurizing chamber 29 formed on the lower end surface of the piston 15. In this embodiment, the outer pressurizing chambers 29a are arranged at three locations at equal intervals in the circumferential direction at the same distance in the radial direction from the axis of the piston 15, and the outer pressurizing chambers 29a are arranged at three locations at equal intervals in the circumferential direction from the axis of the piston 15. A contraction side advancement path 20 is formed in. Note that the other structures are the same as in the above-mentioned embodiment, so the same members are denoted by the same reference numerals and the explanation will be omitted.Since the operation is also the same as in the above-mentioned first embodiment, the explanation will be omitted.

The third embodiment shown in FIG. 5 is one in which the present invention is applied to the bottom side of a hydraulic shock absorber. Note that the bottom side is configured so that a damping force is generated during the contraction stroke.

A partition member 42 that partitions the cylinder lower chamber 18 and an auxiliary chamber 41 defined by the cylinder 13 and the outer cylinder 40 includes a contraction side advancement path 4 that communicates the cylinder lower chamber 18 and the auxiliary chamber 41.
A large diameter disc valve 45, a plurality of small diameter disc valves 46, and a spacer 47 are formed on the downstream side of the contraction side advancement path 43. They are sequentially overlapped along the attached shaft member 48 and attached with a nut 49 to constitute a compression-side damping force generation mechanism 50.

A check valve mechanism 51 is provided on the downstream side of the extension side advancement path 44, and the expansion side advancement path 4 is closed only during the extension stroke of the piston.
4, the oil in the auxiliary chamber 41 flows into the cylinder lower chamber 18.

Further, since the operation of this embodiment is the same as that of the first embodiment, the explanation will be omitted.

Next, with reference to FIGS. 6 to 10, an embodiment will be described in which a set load setting means for applying an initial deflection to the small-diameter disc valve 26 or 46 in the second or third embodiment is provided. Note that the same members as in each of the above embodiments are given the same reference numerals and detailed explanations will be omitted.

First, the fourth embodiment shown in FIG. 6 is the same as the second embodiment described above, except that a set load setting means for giving an initial deflection to the small-diameter disc valve 26 is provided. This is a ring 52 interposed between the outer peripheral end of the disc valve 26 and the large diameter disc valve 2Sa. Note that the large-diameter disc valve 25a is not provided with a hole 31 for reducing rigidity.

With this configuration, the small diameter disc valve 26 is bent by the ring 52 so that the outer circumferential side thereof is separated from the large diameter disc valve 25a, and the pressure F3 at which the small diameter disc valve 26 opens is applied to the pressure F3 of the second embodiment. 1st than pressure F2
The damping force characteristic can be increased as shown in FIG. 5 (this damping force characteristic is shown by line G in FIG. 15). And this pressure F
3 can be adjusted as appropriate by changing the thickness (width in the axial direction) of the ring 52 and changing the amount of deflection of the small diameter disc valve 26.

Note that in order to increase the opening pressure of the small-diameter disc valve 26, it is possible to increase the plate thickness of the small-diameter disc valve 26 to increase its rigidity, or to increase the number of disc valves. When changed, the rate of increase in damping force (first
There are problems such as the gradient of the line G in FIG. 5 inevitably becoming large, making it impossible to obtain the desired damping force characteristics, increasing the weight, and increasing the overall length of the hydraulic shock absorber. In contrast, with the configuration of this embodiment, the opening pressure of the small-diameter disc HARTZ 26 can be increased without changing the rate of increase in damping force, increasing the weight, or increasing the length. It can be modified to make it lighter and smaller.

The fifth embodiment shown in FIG. 7 is the same as the third embodiment except that a set load setting means is provided to give an initial deflection to the small diameter disc valve 46. This is a ring 53 interposed between the outer peripheral end of the Harz 46 and the large diameter disc valve 45. Note that this effect is the same as that of the fourth embodiment, so a description thereof will be omitted (the damping force characteristic is shown by line H in FIG. 15).

In the sixth embodiment shown in FIG. 8, instead of the ring 52 serving as the set load setting means in the fourth embodiment, a ring 52 is provided near the outer circumference of a small-diameter disc valve 26a that abuts a large-diameter disc valve 25a. A protrusion 54 is integrally formed, and the tip of the protrusion 54 is brought into contact with the large diameter disc valve 25a to give initial deflection to the small diameter disc valve 26. Note that this protrusion 54 may be formed partially or over the entire circumference. Further, the small-diameter disc valve 25a on which the protrusion 54 is formed may be turned upside down and assembled so that the tip of the protrusion 54 contacts another small-diameter disc valve 26.

The seventh embodiment shown in FIG. 9 is a small-diameter disc valve in which a stepped portion 55 is bent on the outer circumferential side instead of using the small-diameter disc valve 26a on which the protrusion 54 of the sixth embodiment is formed. 26b is used. This stepped portion 55 is brought into contact with the large-diameter disc valve 25a to give initial deflection to the small-diameter disc valve 26. Note that this stepped portion 55 may be formed partially or over the entire circumference, and the small-diameter disc valve 26b on which the stepped portion 55 is formed may be turned over to form the stepped portion 55.
It is also possible to assemble the disc valve 26 so that it is in contact with another small-diameter disc valve 26. The effects of the sixth and seventh embodiments are the same as those of the fourth embodiment, or the cost can be reduced by not using the ring 52. Furthermore, by applying the small diameter disc valves 26a and 26b of this structure to the fifth embodiment, a small diameter disc valve 4 is used instead of the ring 53.
6 may be given an initial deflection.

The eighth embodiment shown in FIG. 10 is another example of the set load setting means, and is a small-diameter disc valve 26c that is previously deformed into a dish shape. Then, assemble this small-diameter disc valve 26c so that it becomes flat (the small-diameter disc valve 26c in the first to third embodiments).
46), the state is the same as when initial deflection is applied to a small diameter disc valve. In this case, the pressure at which the small-diameter disc valve 26c opens can be adjusted as appropriate depending on the amount of deformation or the number of disks used.

Next, a ninth embodiment will be described using FIG. 11.

In this embodiment, a spring member 56 is used in place of the small diameter disc valve 26 in the second embodiment, and the same members as in the second embodiment are given the same reference numerals and detailed explanations will be given. is omitted.

Nut 39a for assembling the rebound damping force generation mechanism 24a
A flange portion 57 is integrally formed in the flange portion 57.
A spring member 56 made of a coil spring is interposed between the large-diameter disk valve 25 and the large-diameter disk valve 25. Note that the position where the spring member 56 of the large-diameter disc valve 25 comes into contact corresponds to the partition wall 30 between the inner pressurizing chamber 28 and the outer pressurizing chamber 29a.

When the spring member 56 is interposed in contact with the large-diameter disc valve 25 without applying a pressing force, the same effect as that of the small-diameter disc valve 26 of the second embodiment is obtained, When the large-diameter disc valve 25 is interposed so as to apply a pressing force, the effect is the same as that of the small-diameter disc valve 26 of the fourth embodiment, which is given initial deflection by the set load setting means. Further, by changing the rigidity of the large diameter disc valve and the elastic force of the spring member 56, various damping force characteristics can be obtained.

The tenth embodiment shown in FIG. 12, like the ninth embodiment, uses a spring member 58 in place of the small diameter disc valve 46 of the third embodiment in a compression damping force generating mechanism 50a on the bottom side.
It was applied to

This is a retainer 6 integrally formed with a flange portion 59.
0, and a spring member 58, which is a coil spring, is interposed between the flange portion 59 and the large-diameter disc valve 45. Note that the operation is the same as in the ninth embodiment.

The eleventh embodiment shown in FIG. 13 is designed so that the damping force characteristics can be changed smoothly, and this configuration will be explained.

A retainer 63 is connected to the lower end surface of the piston 62 that is slidably fitted into the cylinder 61.
two concentric annular grooves 64 and 65 formed in 3;
An inner pressurizing chamber 67 and an outer pressurizing chamber 68 are constituted by the large diameter disc valve 66 that abuts the retainer 63. The inner pressurizing chamber δ7 is arranged radially inward from the outer circumference of the small-diameter disc valve 69, and the outer pressurizing chamber 68
is expanded radially outward from the outer periphery of the small-diameter disk hull pro 9 and is disposed inward from the outer periphery of the large-diameter disk valve 66. The extension-side advancement path 70 branches at the junction between the piston 62 and the retainer 63 and communicates with the inner pressurizing chamber 67 and the outer pressurizing chamber 68 .

An orifice passage 72 consisting of a notch that communicates the outer pressurizing chamber 68 and the lower cylinder chamber 71 is formed on the outer peripheral side of the retainer 63 that the large-diameter disc valve 66 comes into contact with.

Large diameter disc valve 66 and small diameter disc valve 69
A medium-diameter disk valve 73 smaller than the diameter of the large-diameter disk HURZ 66 and larger than the diameter of the small-diameter disk HURZ 69 is sandwiched between the two. The medium-diameter disc valve 73 has a hydraulic pressure F:l (F + < F i ) greater than the hydraulic pressure F1 when the pressure inside the outer pressurizing chamber 68 increases and the outer peripheral side of the large-diameter disc valve 66 bends. Pressurized chamber 6
The rigidity is set so that the valve opens when applied from 8. In addition, the small diameter disc valve 69 has a hydraulic pressure F that is higher than the hydraulic pressure F3 when the medium diameter disc Harz 73 is bent.
The rigidity is set so that the valve opens when 2 (PI<F:l<F2) is applied from the inner pressurizing chamber 67.

Note that the structure of the values in the figure is the same as in the first embodiment, so the explanation will be omitted.

The effect of this configuration will be explained based on FIG. 13 and FIG. 16.

When the piston 62 is pulled up during the extension stroke and the oil fluid flows in the extension bias passage 70 and the pressure in the inner pressurizing chamber 67 and the outer pressurizing chamber 68 increases, first, the orifice passage 7
1 in Figure 16 due to 2. A damping force having the orifice characteristics shown by the line is generated, and then the oil pressure in the outer pressurizing chamber 68 or Fl
When this happens, the outer peripheral side of the large-diameter disc valve 66 bends to generate the damping force shown by the line 12 in FIG. When the hydraulic pressure in the inner pressurizing chamber 27 reaches F2, the small-diameter disc valve 69 is bent to generate a damping force as shown by the line 14 in FIG. 16.

In this way, smooth damping force characteristics can be obtained by optimally combining the damping force of the orifice characteristic and the damping force generated by sequential bending of each disc valve 66, +19.73.

In addition, in this embodiment, there are three disc valves: a large diameter disc valve 66, a medium diameter disc valve 73, and a small diameter disc valve 69.
Although different types of disc valves were used, the opening pressure increases as the diameter becomes smaller. Four or more types of disc valves with different diameters may also be used, and the more types there are, the smoother the damping force characteristics can be obtained. .

The twelfth embodiment shown in FIG. 14 is an embodiment in which the configuration of the eleventh embodiment is applied to a compression damping force generation mechanism on the bottom side of a hydraulic shock absorber. Note that the configuration of the retainer 74 and the configuration of each disc valve 75, 76, and 77 in the figure are the same as in the eleventh embodiment, and the other configurations are the same as in the third embodiment, so explanations will be omitted. do. Further, the operation is the same as that of the eleventh embodiment (the damping force characteristics are
(shown in the line).

Note that the present invention is not limited to the above embodiments, and may be configured as follows.

The inner pressurizing chamber and the outer pressurizing chamber in each embodiment may have any shape as long as the hydraulic pressure in the communication passage can be appropriately applied to the disc valve.

Further, the number of each disc valve may be appropriately set so as to obtain an optimal damping force characteristic depending on the vehicle.

Furthermore, in each embodiment, the extension side damping force generation mechanism provided on the piston side and the compression side damping force generation mechanism provided on the bottom side can be combined as appropriate, so that the damping force during the extension stroke and the compression stroke are The characteristics can be changed or kept the same, and can be set as appropriate.

(Effects of the Invention) As explained in detail above, the present invention combines a large diameter disc valve and a small diameter disc valve that open at different pressures from the communication passage side, and An outer pressurizing chamber is provided which communicates with the communication passage and expands radially outward from the outer circumference of the 174X diameter disc valve, and the pressure of the oil in the outer and inner pressurizing chambers increases due to the movement of the piston. Accordingly, the outer circumferential side of the large-diameter disc valve and the small-diameter disc valve are sequentially opened to generate damping force, so by changing the rigidity of the disc valve, the damping force characteristics can be freely adjusted. be able to.

Furthermore, if a set load setting means is provided, the pressure at which the small-diameter disc valve opens can be changed to a higher value, and the degree of freedom in adjusting the damping force characteristics can be further expanded.

In addition, even if a spring member is used instead of a small-diameter disc valve, by changing the elastic force of the spring member,
Damping force characteristics can be adjusted freely.

This makes it possible to set the optimum damping force characteristics for the vehicle, thereby improving handling stability and ride comfort.

In addition, since the disc valve or the spring member can be assembled one after another, it is possible to assemble the valve and the spring member one after another, so that the assembly is easy to assemble and replace.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing a first embodiment of a hydraulic shock absorber of the present invention. FIG. 2 is a diagram showing damping force characteristics in the hydraulic shock absorber of the first embodiment. 4 is a longitudinal cross-sectional view of main parts showing a second embodiment of the hydraulic shock absorber of the present invention, FIG. 4 is a cross-sectional view taken along the N-mV line in FIG. 3, and FIG. FIG. 6 is a vertical cross-sectional view of main parts showing a fourth embodiment of the hydraulic shock absorber of the present invention. FIG. 7 is a longitudinal cross-sectional view of main parts showing a fourth embodiment of the hydraulic shock absorber of the present invention. FIG. 8 is a vertical cross-sectional view of a main part showing a sixth embodiment of a hydraulic shock absorber of the present invention; FIG. 9 is a longitudinal cross-sectional view of a main part of a hydraulic shock absorber of the present invention FIG. 10 is a vertical cross-sectional view of a small diameter disc valve used in the eighth embodiment of the hydraulic shock absorber of the present invention; FIG. 11 is a vertical cross-sectional view of the main part showing the seventh embodiment; FIG. 12 is a vertical cross-sectional view of a main part showing a ninth embodiment of a hydraulic shock absorber according to the present invention; FIG. 12 is a longitudinal cross-sectional view of a main part showing a tenth embodiment of a hydraulic shock absorber according to the present invention; FIG. 14 is a vertical sectional view of essential parts showing the eleventh embodiment of the hydraulic shock absorber of the present invention, FIG. 14 is a longitudinal sectional view of essential parts showing the twelfth embodiment of the hydraulic shock absorber of the present invention, 8 is a diagram showing damping force characteristics of the fourth embodiment shown in the figure and the fifth embodiment shown in FIG. 7. FIG. FIG. 16 shows the eleventh embodiment and the first embodiment shown in FIG.
Figure 4 is a diagram showing the damping force characteristics of the twelfth embodiment, Figure 17 is a vertical sectional view showing the entire conventional hydraulic shock absorber, Figure 18 is the conventional hydraulic shock absorber shown in Figure 17. FIG. 3 is a diagram showing the damping force characteristics of the device. 5, FIG. 7, FIG. 8, FIG. 9, and FIG. 12 are bilaterally symmetrical, so only the right side is shown. 13-...Cylinder 15...Piston 17-
...Cylinder lower chamber 18...Cylinder lower chamber 19...
・Elongation bias passage 24...Elongation side damping force generation mechanism 25...Large diameter disc valve 26...Small diameter disc valve 28...Inner pressure chamber 29...Outer pressure chamber 30
...Partition wall 52...Ring (Cera 56...Spring means

Claims (3)

[Claims] (1) In a hydraulic shock absorber having a damping force generation mechanism that generates damping force by controlling the flow of oil generated in a communication path that communicates two partitioned chambers due to the sliding of a piston in a cylinder. , a large-diameter disk valve in which the damping force generation mechanism is arranged downstream of the communication path; a disk valve stacked on the large-diameter disk valve and having a smaller diameter than the large-diameter disk valve; an inner pressurizing chamber that is arranged radially inward on the opposite side of the small-diameter disk valve from the small-diameter disk valve and communicates with the communication passage; is arranged radially outward, extends radially outward from the outer periphery of the small-diameter disc valve, communicates with the communication passage, and applies hydraulic pressure to the outer periphery of the large-diameter disc valve. A hydraulic shock absorber comprising: an outer pressurizing chamber; (2) The hydraulic shock absorber according to claim (1), further comprising set load setting means for applying initial deflection to the small-diameter disc valve. (3) In a hydraulic shock absorber having a damping force generation mechanism that generates damping force by controlling the flow of oil generated in a communication path that communicates two partitioned chambers due to the sliding of a piston in a cylinder. , a disc pulp in which the damping force generation mechanism is arranged on the downstream side of the communication passage, and an inner part arranged at different positions in the radial direction of the disc valve, each communicating with the communication passage and applying hydraulic pressure to the disc valve. a pressurizing chamber and an outer pressurizing chamber; disposed at a position corresponding to a partition wall that partitions between the inner pressurizing chamber and the outer pressurizing chamber on the opposite side of the disc valve from each of the pressurizing chambers; A hydraulic shock absorber comprising: a spring means for pressing the disc valve toward the pressurizing chamber;