JPH10169695A - Damping force variably controlled damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damping force variably controlled damper wherein limitation on an arrangement space can be relaxed and wiring arrangement of a lead wire can be simplified. SOLUTION: In a damping force variably controlled damper 6 partitioning inside a cylinder 7 by a piston 9 into an extension/pressure side oil chamber 7a, 7b, having a storage chamber 71a accumulating surplus operating oil, changing fluidic resistance of operating oil by a control valve 60, so as to variably control damping force, in a side end part of an opposite piston rod 10 of the cylinder 7, the control valve 60 is arranged, in a side of the piston 9 of the control valve 60, a base valve 61 is arranged, which permits only a flow of operating oil to the pressure side oil chamber 7b and impedes a flow of operating oil from the pressure side oil chamber 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable damping force control type hydraulic shock absorber in which a damping force is variably controlled according to running conditions and the like.

[0002]

2. Description of the Related Art In recent years, automobiles and motorcycles sometimes employ a variable damping force control type hydraulic shock absorber that freely controls a damping force according to road surface conditions, running conditions and the like. The shock absorber detects a traveling speed and a position of a piston relatively moving in a cylinder, and traveling conditions such as a traveling speed, a steering angle, and acceleration / deceleration of the vehicle, and sets a damping characteristic pattern set in advance according to the traveling condition. Is configured to variably control the damping force based on

[0003] As a structure in which a damping force control valve for changing the flow resistance of hydraulic oil is assembled in this type of shock absorber, conventionally, for example, as shown in FIG.
Control valve 1 on the outer wall of the outer cylinder 101 disposed outside
02 fixed external type (Japanese Patent Application No. 3-193)
489), or an internal type in which a control valve 105 is built in a piston 104 inserted and arranged in a cylinder 103 as shown in FIG.

[0004]

However, in the above-mentioned conventional external shock absorber, the damping force control valve 102 has a structure projecting radially outward from the outer cylinder 101.
There is a problem that space restrictions when attaching to the vehicle body are so large. In particular, when the projections are arranged on the front wheels of a four-wheeled vehicle, the projections may interfere with the suspension mechanism and the tire, and there is a problem that the application is narrowed.

Although the conventional internal type is not restricted by the lateral projection, the lead wire of the control valve is taken out from the upper end of the piston rod, so that the lead wire is taken out. There is a problem that the portion easily interferes with the vehicle body and the like, and there is a problem that the wiring of the lead wire tends to be complicated as compared with the external type.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and provides a damping force variable control type shock absorber which can reduce restrictions on an arrangement space and can simplify wiring of a lead wire. The purpose is.

[0007]

According to the present invention, a cylinder is defined by a piston into an expansion-side oil chamber and a compression-side oil chamber, and a storage chamber for storing excess hydraulic oil is provided. In a damping force variable control type shock absorber in which a damping force is variably controlled by being changed by a control valve, the control valve is disposed at an end of the cylinder opposite to a piston rod, and the piston side of the control valve is disposed on the piston side. And a base valve that allows only the flow of the hydraulic oil to the pressure side oil chamber and blocks the flow of the hydraulic oil from the pressure side oil chamber.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIGS. 1 to 4 are diagrams for explaining a damping force variable control type shock absorber according to a first embodiment of the present invention. FIG. 1 is a schematic diagram of a suspension system in which the shock absorber of the present embodiment is adopted. FIG. 2 is a sectional view of the shock absorber, FIG. 3 is a sectional side view of a control valve of the shock absorber, and FIG. 4 is a view showing a pilot valve portion of the shock absorber.

In the figure, reference numeral 1 denotes a suspension system in which the shock absorber of the present embodiment is adopted. The suspension system 1 pivotally supports a suspension arm 3 on which wheels 2 are pivotally supported by a vehicle body 4 so as to be vertically swingable. A coil spring 5 and a shock absorber 6 are provided between the suspension arm 3 and the vehicle body.

In the shock absorber 6, an outer cylinder 71 is arranged so as to surround the outside of the cylinder 7 defined by the piston 9 in the extension-side oil chamber 7a and the compression-side oil chamber 7b.
1 is closed by a rod guide 7c, the lower end of the outer cylinder 71 is closed by a bottom cover 7d, the lower end of the cylinder 7 is closed by a base valve 61, and between the base valve 61 and the cover plate 7d. It has a structure in which a damping force control valve 60 for variably controlling the damping force generated by the relative movement of the piston 9 is provided. That is, the damping force control valve 60 is located at the bottom of the cylinder 7 on the side opposite to the piston rod 10, and the base valve 61 is located at the piston 9 side of the control valve 60.

The piston 9 is provided with a one-way valve 9a for permitting only the flow of hydraulic oil from the pressure side oil chamber 7b to the expansion oil chamber 7a. The bottom lid 7d is connected to the suspension arm 3, and the upper end of a piston rod 10 connected to the piston 9 is connected to the vehicle body 4.

The control valve 60 of the shock absorber 6 includes:
Various sensors 11 for detecting data indicating running conditions such as the relative movement speed and position of the piston 9 with respect to the cylinder 7 and the steering speed, steering angle, acceleration and deceleration of the vehicle, and the control valve 60 according to the running conditions. Is connected to a control device (controller) 12 for controlling the control based on a preset attenuation characteristic pattern. Here, as the damping force characteristic, a user's favorite one may be appropriately input to the control device 12 by a manual switch or the like. In addition,
Reference numeral 13 denotes an electric wiring connecting the control device 12 and the control valve 60.

The space formed between the cylinder 7 and the outer cylinder 71 serves as a storage chamber 71a for storing an amount of hydraulic oil corresponding to the volume of the piston rod 10 entering the cylinder. A guide pipe 72 is inserted into the storage chamber 71a in the direction of the cylinder axis. The upper end opening of the guide pipe 72 communicates with the extension-side oil chamber 7a through an annular communication hole 72a formed in the guide rod 7c, and the lower end opening is connected to the base valve 61.

The base valve 61 has a supply passage 63 for communicating the pressure side oil chamber 7b with the storage chamber 71a. A disc-shaped one-way valve 64 for opening and closing the supply passage 63 is fixed to the upper surface of the base valve 61 with a bolt 65, thereby moving the storage chamber 71a from the pressure side oil chamber 7b.
The flow of the hydraulic oil from the pressure side oil chamber 7b is blocked while allowing only the flow of the hydraulic oil to the hydraulic pressure chamber 7b.

The base valve 61 has a hydraulic oil introduction passage 66 formed separately from the supply passage 63. The guide pipe 72 is provided at the inlet of the introduction passage 66.
Is connected to the storage chamber 71a through the damping force control valve 60. As a result, the hydraulic oil is supplied from the inside of the cylinder 7 to the guide pipe 72 and the introduction passage 6 in both the compression stroke and the extension stroke.
6, the liquid is returned to the storage chamber 71a via the control valve 60.

The damping force control valve 60 is assembled in the following procedure. A lower body 15 that houses a linear solenoid 44, an intermediate body 16 that houses a pilot valve 35, and an upper body that houses a main valve 18 are arranged in a cylindrical outer case 14 having a bottom with an open upper end. 17 is loaded, and the upper edge spigot portion of the outer case 14 is press-fitted into the lower edge spigot portion of the base valve 61 to be connected to the lower end portion of the cylinder 7. The cylinder 7 to which the control valve 60 is coupled is inserted into the outer cylinder 71, and the lower part of the outer case 14 of the control valve 60 is fitted and inserted into the accommodation hole 7f of the bottom cover 7d. Note that 67a, 67b,
67c is a seal ring.

The lead wire 13 for supplying power to the linear solenoid 44 is connected to the linear solenoid 44 by inserting the connector 13a from the opening 7e after inserting the control valve 60 into the bottom cover 7d. Is done.

A slide hole 1 is provided at the axis of the upper body 17.
A main valve 18 is slidably mounted in the slide hole 17a. The upper body 17 has an introduction passage 6 for the base valve 61.
6, a main oil passage 19 communicating with the main oil passage 1 is formed.
The opening 19 a of the valve 9 is opened and closed by the main valve 18. The main oil passage 19 is provided in the oil hole 1 formed in the outer case 14.
It communicates with the storage chamber 71a via 4a.

The main valve 18 has a concave chamber 18a at the lower part,
A sealing surface 18b is formed at an upper end portion in a tapered shape and abuts on a peripheral edge (valve seat) of the opening 19a.
The pressure in the cylinder acts on the tip of b through the guide pipe 72.

The upper end of a resin-made or metal-made cylindrical vibration isolating ring 22 is inserted into the concave chamber 18a of the main valve 18 so as to be relatively slidable up and down.
Is in contact with the upper surface of the intermediate body 16. A spacer 26 is provided on the top wall of the concave chamber 18a. The spacer 26 is provided between the lower end flange of the vibration isolating ring 22 and the top wall surface of the concave chamber 18a.
The anti-vibration ring 22 is pressed and fixed to the upper surface of the intermediate body 16 with a double coil spring 23 for urging the main valve 18 upward.

The double coil spring 23 includes large and small coil springs 24, which are stacked in series with the spacer 26 interposed therebetween.
25. The upper end of the large coil spring 24 is
The lower end of the small coil spring 25 is in contact with the inner bottom of the spacer 26, and the upper end of the small coil spring 25 is in contact with the top wall surface of the main valve 18. Here, when the main valve 18 is fully closed, the coil spring dimensions are set such that a slight gap is opened between the upper surface of the flange 26a of the spacer 26 and the top wall surface.

Thus, the concave chamber 18 of the main valve 18 is provided.
The space surrounded by a, the vibration isolating ring 22 and the upper surface of the intermediate body 16 is a sub oil chamber 31. The sub oil chamber 31
Communicates with the introduction passage 66 through a communication hole 26b formed in the spacer 26 and an orifice 18d formed in the main valve 18. Thereby, the pressure in the cylinder is introduced into the sub oil chamber 31.

The sub oil chamber 31 communicates with a pilot passage 36 via a pilot valve 35. The pilot passage 36 communicates with a storage chamber 71a via an oil passage 17e formed in the upper body 17. I have. The pilot passage 36 includes a plurality of radial passages 39 extending in the radial direction from the downstream side of the pilot valve 35, and an annular portion 40 connecting the radial passages 39. It communicates with the passage 17e.

The pilot valve 35 is connected to the intermediate body 16
A valve chamber 41 is recessed in the axial center portion of the
2 so as to be slidable up and down.
2 is urged upward by a linear solenoid 44 via a plunger 43 mounted on the valve shaft 42d.

4 (a) to 4 (c), an annular opening groove (valve hole) 4 is formed on the lower surface of the top wall 41c of the valve chamber 41.
1a is formed, and three substantially elliptical concave grooves 41b are formed on the upper surface.
Are formed, and the concave groove 41b and the opening groove 41a are formed.
The valve chamber 41 and the sub oil chamber 31 can communicate with each other via the.

The valve body 42 has an annular convex portion 42b integrally formed on the upper surface of the disk portion 42a, and has three substantially elliptical through holes 4 communicating from the upper surface side to the lower surface side of the valve body 42.
2c is formed. As the valve body 42 descends, a pilot opening is formed between the convex portion 42b and the peripheral portion (valve seat) of the opening groove 41a, and the flow direction of the hydraulic oil flowing through the pilot opening is determined by the valve. It intersects with the moving direction of the body 42. Here, the upper surface (pressure receiving surface) of the valve seat and the convex portion 42b is orthogonal to the moving direction b of the valve body 42. Accordingly, the substantial opening area of the pilot valve 35 in the stroke can be increased, so that the responsiveness to a change in the running state can be improved and the vibration of the pilot valve 35 can be reduced.

The linear solenoid 44 is built in the lower body 15 and, when excited, applies an upward force corresponding to the exciting force via the plunger 43 to the valve body 4.
2 By controlling the exciting force, the internal pressure of the sub oil chamber 31 at which the pilot valve 35 starts to open changes, and functions as a damping force varying unit. The exciting force is controlled by the magnitude of the current supplied to the linear solenoid 44 via the electric wiring 13.

When the current supply to the linear solenoid 44 is stopped, the valve body 42 is lowered by the pressure in the sub oil chamber 31 until the lower end surface of the plunger 43 comes into contact with the stopper 44b. In this case, the radiation path section 39 of the pilot passage 36 is closed by the outer peripheral surface of the disk section 42a.

On the other hand, the intermediate body 16 has a pressure regulating valve 50 for regulating the pressure in the sub oil chamber 31 to a predetermined pressure when the radiation path portion 39 is closed by the disk portion 42a.
Is provided. The pressure regulating valve 50 is connected to the valve chamber 41.
A ball 50b is provided in a communication hole 50a for communicating the inside of the pilot passage 36 with the inside of the annular portion 40 of the pilot passage 36.
0b is biased in the closing direction by a biasing spring 50c.

The lower end face of the main valve 18, the main valve insertion hole 17a
, The bottom wall 41c of the intermediate body 16, and a space surrounded by the vibration isolating ring 22 slidably inserted into the concave chamber 18 is a damping chamber 54.
The volume of the damping chamber 54 changes with the vertical movement of the main valve 18, that is, with the opening of the main valve 18.

An orifice 53 is formed by a gap between the concave chamber 18a of the main valve 18 and the outer peripheral surface of the vibration isolating ring 22. As a result, when the volume of the damping chamber 54 changes in accordance with the change in the opening degree of the main valve 18, the hydraulic oil flows into the sub oil chamber 31 and the damping chamber 5 through the orifice 53.
4 and at this time, a main valve damping force acting on the main valve 18 is generated. Thus, a damping mechanism for suppressing the vibration of the main valve 18 is configured. Here, the length (damping force) of the orifice 53 is configured to temporarily increase (increase) as the stroke amount of the main valve 18 increases, and then shorten (decrease).

Next, the operation of the shock absorber 6 will be described. When the wheel 2 is pushed up by a convex portion of the road surface and the shock absorber 6 is in a compression stroke, the piston rod 10 and the piston 9 relatively enter the cylinder 7 below FIGS. Since the internal volume of the cylinder is reduced by the integral volume of the piston rod 10 and the one-way valve 9a is provided, the pressure-side oil chamber 7b and the expansion-side oil chamber 7a increase in pressure. It acts on the main valve 18 through the introduction passage 66 and is introduced into the sub oil chamber 31 through the orifice 18d.
Also boosts.

The internal pressure of the sub oil chamber 31 causes the valve body 42
When the opening force acting on the opening exceeds the urging force of the linear solenoid 44, the valve body 42 opens the opening groove 41a, the internal pressure of the sub oil chamber 31 decreases, and the main valve 18 is pushed by the pressure of the introduction hole passage 66. As a result, the hydraulic oil flows into the storage chamber 71a through the guide pipe 72 and the control valve 60 by an amount corresponding to the piston rod entry volume, and at this time, a damper corresponding to the cylinder pressure × the piston rod cross-sectional area is obtained. A pressure damping force is generated.

When the wheel 2 is lowered and the shock absorber 60 is extended, the piston 9 is relatively pulled upward. In this case, since the one-way valve 9a is closed, the extension-side oil chamber 7a
The expansion side pressure acts on the main valve 18 via the guide pipe 72 and the introduction passage 66, and is introduced into the sub oil chamber 31 through the orifice 18d, so that the sub oil chamber 31 also pressurizes.

When the opening force acting on the valve element 42 due to the internal pressure of the sub oil chamber 31 exceeds the urging force of the linear solenoid 44, the valve element 42 opens the opening groove 41a and the sub oil chamber 3
1, the main valve 18 is pushed open by the pressure of the introduction passage 66, whereby the hydraulic oil flows into the storage chamber 71a from the expansion-side oil chamber 7a, and at this time, the expansion-side pressure × (piston area) -Piston rod area). The hydraulic oil in the reservoir 71a is supplied to the pressure side oil chamber 7b through the one-way valve 64.

According to the present embodiment, the base valve 61 is disposed on the bottom of the cylinder 7 opposite to the piston rod 10, and the damping force control valve 60 is provided between the lower surface of the base valve 61 and the bottom cover 7d. Since it is arranged, the control valve is
It can be prevented from protruding radially outward from the position 1, and the restrictions on the space at the time of attachment to the vehicle body can be relaxed, and the periphery of the suspension can be made compact. Therefore, it can be used for the front wheels of a four-wheeled vehicle, and the use can be expanded.

Further, since the control valve 60 is disposed at the bottom of the cylinder 7, the lead wire 13 can be connected to the control valve 60 through the opening 7e of the bottom cover 7d, and can be routed in a conventional piston rod. The wiring structure of the lead wire can be simplified as compared with the above. Here, since the overall length in the axial direction of the shock absorber 6 is almost the same as that of the conventional internal type, it is unlikely that the provision of the control valve 60 at the bottom of the cylinder causes a trouble in the layout in the vertical direction. rare.

FIG. 5 is a view for explaining a damping force variable control type shock absorber according to a second embodiment of the present invention. In the figure, FIG.
The same reference numerals indicate the same or corresponding parts.

In the shock absorber 80 of the present embodiment, a base valve 81 is provided at the bottom of the cylinder 7, and the base valve 81
A damping force control valve 82 is disposed between the lower surface of the bottom cover 7d and the bottom lid 7d. The basic structure of the control valve 82 is the same as that of the above embodiment. Hereinafter, only different portions will be described.

The base valve 81 is provided with a supply passage 66 for communicating the pressure side oil chamber 7b and the storage chamber 71a, and a one-way valve 64 is provided in the supply path 66 to the pressure side oil chamber 7b. Only flow is allowed. The main oil passage 19 is connected to the supply passage 66 through a main valve 83 of a control valve 82.
The main oil passage 19 is connected to the lower end opening of a guide pipe 72 that communicates with the extension-side oil chamber 7a.

The main valve 83 is connected to the opening 1 of the main oil passage 19.
The valve 83a has a valve portion 83a protruding from the supply passage 66 toward the supply passage 66, and an annular recess 83b is formed on the outer peripheral surface of the valve portion 83a. As a result, the hydraulic oil flows into the main oil passage 19 from the extension-side oil chamber 7a via the guide pipe 72, and from there, passes through the gap between the concave portion 83b of the main valve 83 and the opening 19a and from the supply passage 66 to the storage chamber 71a. Leaked to In this case, the hydraulic oil is supplied from the supply passage 66 to the storage chamber 7 during the compression stroke.
In the extension stroke, part or all of the fluid flows from the supply passage 66 through the one-way valve 64 to the pressure side oil chamber 7b.

Here, in the shock absorber 80, the hydraulic oil flows from the main oil passage 19 side through the opening 19a of the main valve 83. On the other hand, in the first embodiment, the hydraulic oil flows from the opening 19a of the main valve to the main oil passage 19 side.

Also in this embodiment, since the base valve 81 and the damping force control valve 82 are provided at the bottom of the cylinder 7, there is a restriction on the space when the control valve does not protrude from the outer cylinder 71 and is mounted on the vehicle body. In addition, the same effect as in the above-described embodiment can be obtained, in which the configuration of the lead wire can be simplified and the wiring structure of the lead wire can be simplified.

In the above embodiment, the piston rod 10 is connected to the vehicle body 4 and the cylinder 7 is connected to the wheel 2. However, in the present invention, the piston rod 10 is connected to the wheel 2 and the cylinder 7 is connected to the vehicle body 4. Of course, the present invention can also be applied to a so-called inverted type shock absorber.

[0045]

As described above, according to the damping force variable control type shock absorber according to the present invention, the control valve is disposed at the end of the cylinder opposite to the piston rod, and the base valve is disposed at the piston side of the control valve. Since the control valve is disposed, it is possible to prevent the control valve from protruding outward in the radial direction from the cylinder, so that there is an effect that restrictions on an arrangement space can be eliminated, and there is an effect that lead wires can be easily arranged.

[Brief description of the drawings]

FIG. 1 is a schematic view of a suspension system employing a damping force variable control type shock absorber according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional side view of the shock absorber.

FIG. 3 is a sectional side view of a damping force control valve of the shock absorber.

FIG. 4 is a view showing a pilot valve portion of the damping force control valve.

FIG. 5 is a sectional view showing a shock absorber according to a second embodiment of the above embodiment.

FIG. 6 is a schematic configuration diagram showing a conventional external type shock absorber.

FIG. 7 is a schematic configuration diagram showing a conventional shock absorber of a built-in piston type (internal type).

[Explanation of symbols]

 6,80 damping force variable control type shock absorber 7 cylinder 7a extension side oil chamber 7b compression side oil chamber 9 piston 10 piston rod 60,82 damping force control valve 61,81 base valve 71a storage chamber

Claims (1)

[Claims] An internal cylinder is defined by a piston into an expansion-side oil chamber and a compression-side oil chamber, and a storage chamber for storing excess hydraulic oil is provided. Damping is achieved by changing the flow resistance of the hydraulic oil by a control valve. In the damping force variable control type shock absorber configured to variably control the force, the control valve is disposed at an end of the cylinder opposite to the piston rod, and the control valve is actuated to the pressure side oil chamber on the piston side. A damping force variable control type shock absorber characterized by including a base valve that allows only oil flow and prevents flow of hydraulic oil from the pressure side oil chamber.