JPH0545279U - Hydraulic shock absorber - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Easy initial adjustment and damping force adjustment.
The structure of the circuit is simple and the power consumption is saved. A piston rod 3 is movably inserted into a cylinder 1 via a piston 2, the piston defines two oil chambers 6 and 7 in the cylinder, and the piston has a port 8 for opening and closing the two oil chambers. And a damping valve 9, a piston rod is provided with a bypass 10 for communicating two oil chambers, and a valve 13 for adjusting the opening area of the bypass is provided in the middle of this bypass so as to be vertically movable.
One end of 3 is a hydraulic shock absorber carried by an initial adjusting piston 20 provided on the cylinder 1 side or the piston rod 3 side, and a damping force adjusting piston 16 facing the control rod is provided on the outer end of the piston rod to make an initial adjustment. A hydraulic pressure is introduced from a common hydraulic pressure source to the piston 20 and the damping force adjusting piston 16.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic shock absorber that is interposed between a vehicle body and an axle and that also serves as a suspension that damps vibrations from the road surface.

[0002]

[Prior Art]

 A hydraulic shock absorber that also serves as a suspension has a suspension spring interposed between the cylinder side and the piston rod side, and a bypass that connects two oil chambers partitioned by the piston is provided in the piston rod. It is known that a valve for adjusting the damping force is provided therein.

One end of the suspension spring is carried by a hydraulically driven piston for initial adjustment, and by moving this piston hydraulically, the initial corresponding to the amount of movement is adjusted.

On the other hand, the damping force adjusting valve is connected to a control rod that is movably inserted in the piston rod, and this control rod is operated to move up and down by an electric or manual actuator from the outside. The damping force is adjusted by setting the bypass opening area according to the amount of valve movement.

[0005]

[Problems to be solved by the device]

 In the above conventional hydraulic shock absorber, hydraulic pressure is used when adjusting the initials of the suspension springs and damping force, and an electric or manual actuator is used. Since the power sources are operated separately, the operation is troublesome, the hydraulic circuit and the electric circuit are complicated, and the power source which is a separate power source is required, resulting in a waste of power consumption.

Therefore, the present invention is to provide a hydraulic shock absorber in which initial adjustment and damping force adjustment are easy, a circuit and the like have a simple structure, and power consumption can be saved.

[0007]

[Means for Solving the Problems]

 In order to achieve this object, the structure of the present invention is such that a piston rod is movably inserted into a cylinder through a piston, the piston defines two oil chambers in the cylinder, and the piston has two oil chambers. A port that opens and closes the oil chamber and a damping valve are provided, and a bypass that connects the two oil chambers is provided on the piston rod.In the middle of this bypass, a valve that adjusts the opening area of the bypass is provided so that it can move up and down. This valve is operated vertically by a control rod inserted in the piston rod, and a suspension spring is interposed between the outer circumference of the cylinder and the upper part of the piston rod. One end of the suspension spring is provided on the cylinder side or the piston rod side. In the hydraulic shock absorber carried by the initial adjustment piston, the damping force that opposes the control rod is applied to the outer end of the piston rod. The integer piston provided, in which as the damping force adjusting piston and the initial adjustment piston hydraulic pressure is derived from a common hydraulic source.

[0008]

[Action]

 Since the hydraulic power source is common, the hydraulic pressure is simultaneously guided from one hydraulic pump to the initial adjustment piston and the damping force adjustment piston, and the initial adjustment piston sets the initial corresponding to the movement in the suspension spring, and the damping force adjustment piston Adjusts the opening area of the bypass by moving the control rod and valve.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention.

The hydraulic shock absorber A includes a cylinder 1 and a piston rod 3 which is movably inserted into the cylinder 1 via a piston 2. The cylinder 1 is connected to a vehicle body side via a bracket 4, and the piston rod 3 Is in contact with the axle side via the bracket 5.

However, the cylinder 1 may be connected to the axle side and the piston rod 3 may be connected to the vehicle body side.

A piston 2 divides a cylinder 1 into a piston side oil chamber 6 and a rod side oil chamber 7, and the two oil chambers 6 and 7 are connected via a port 8 provided in the piston 2 and a damping valve 9. The damping valve 9 is opened and closed to generate, for example, an extension side damping force at the time of expansion and contraction operation.

Similarly, the two oil chambers 6 and 7 form a bypass 10 provided in the piston rod 3 and communicate with each other through a vertical passage 11 and a horizontal passage 12, and the needle chamber is provided in the bypass 10 and is vertically movable. The valve 13 adjusts the opening area of the bypass 10 and generates a damping force of expansion / compression in accordance with the opening area during expansion / contraction operation.

The valve 13 is connected to a control rod 14 that is vertically movably inserted in the piston rod 3, and an outer end of the control rod 14 projects into a damping force adjusting cylinder 15 in the bracket 5.

A damping force adjusting piston 16 is vertically movably inserted into the cylinder 15, and the piston 16 is brought into contact with or joined to the outer end of the control rod 14 and simultaneously works in the vertical direction.

A hydraulic oil source 17 is connected to the back oil chamber 17 of the damping force adjusting piston 16 either directly or via a damping force adjusting sub cylinder.

A sleeve 18 is fitted on the outer circumference of the cylinder 1, and a vehicle height adjusting cylinder 19 is provided on the outer circumference of the sleeve 18, and an initial adjusting piston 20 is vertically movably inserted into the cylinder 19. The upper end of the suspension spring 6 is carried on the end portion of the piston 20 via a spring sheet 21, and the lower end of the suspension spring 6 is supported by a spring seat 24 provided on the lower bracket 5 so as to support the piston 20. A hydraulic power source is connected to the upper end side oil chamber 22 directly or via an initial adjusting sub-cylinder.

A hydraulic circuit is shown in FIG. 2. The oil chamber 17 of the damping force adjusting cylinder 15 in the bracket 5 communicates with the damping force adjusting sub-cylinder C via the circuit K, and is used as a vehicle height adjusting cylinder. The oil chamber 22 of 19 is connected to a sub-cylinder B for initial adjustment via a circuit M.

The damping force adjusting sub-cylinder C is divided into two pressure chambers s and t via a free piston v, and the moving amount of the free piston v is regulated by a dial type stopper u. Is guided to the oil chamber 17 of the damping force adjusting cylinder 15 to move the piston 17, the control rod 14, and the valve 13 in the vertical direction.

In the vehicle height adjusting sub-cylinder B, two pressure chambers q and r are defined in the cylinder portion o via the free piston p, and the hydraulic pressure corresponding to the movement amount of the free piston p is used as the vehicle height adjusting cylinder. It is guided to the oil chamber 22 of 19 and moves the free piston 20 up and down to adjust the initial of the suspension spring 23, and at the same time, the vehicle height is set according to the bending amount of the suspension spring 23.

The damping force adjusting sub-cylinder C and the initial adjusting sub-cylinder B are connected to a pump P or a tank T which is a hydraulic pressure source via circuits L and N, a check valve D, and a circuit I.

The check valve D is connected to the pump P or the tank T via the pilot circuit J, and is opened when the pump P is driven.

E and F are relief valves.

When the motor M drives the pump P to rotate in the normal direction, the oil in the tank T is sucked from the check valve H and discharged to the circuit I. The flow is divided into the pressure chamber s of the force adjusting sub-cylinder C.

Therefore, the free piston p of the initial adjustment sub-cylinder B moves in accordance with the amount of oil supplied, guides the hydraulic pressure corresponding to this amount of oil to the oil chamber 17 of the vehicle height adjustment cylinder 19, and suspends the suspension spring. Adjust the initials of 23 and raise the vehicle height.

On the other hand, in the damping force adjusting sub-cylinder C, the free piston v moves according to the amount of oil supplied, and the hydraulic pressure corresponding to this amount of oil is introduced into the oil chamber 17 of the damping force adjusting cylinder 15. At this time, the moving amount of the free piston v is regulated by the stroke of the stopper u, and the regulated hydraulic pressure is guided to the oil chamber 17. Therefore, the hydraulic pressure is adjusted by rotating the stopper u to adjust the stroke, and thus the damping force is also adjusted.

That is, the hydraulic pressure guided to the oil chamber 17 presses the damping force adjusting piston 16 and makes a stroke in accordance with the hydraulic pressure, so that the control rod 14 and the valve 13 also move according to this stroke, and the valve 13 moves. The opening area of the bypass 10 is set according to the amount, and a damping force corresponding to this opening area is generated.

When the pump P is rotated in the reverse direction, the oil of the circuit I is sucked and returned to the tank T from the relief valve F, the check valve D is opened by the pilot pressure at this time, and the oil chamber 22 of the vehicle height adjusting cylinder 19 is opened. The oil and the oil in the oil chamber 17 of the damping force adjusting cylinder 15 are returned to the pressure chamber q of the vehicle height adjusting cylinder B and the pressure chamber t of the damping force adjusting sub-cylinder C, respectively, so that the vehicle height is reduced. However, the initial becomes small and the damping force by the valve 13 also becomes low.

FIG. 3 shows another embodiment of the present invention.

The same structures as those in FIG. 1 are designated by the same reference numerals.

In this embodiment, the damping force adjusting cylinder and the vehicle height adjusting cylinder are all incorporated in the bracket on the piston side.

The operation is the same as that of the embodiment shown in FIG. 1, but the same vehicle height and damping force adjusting sub-cylinders are used. However, they may be provided separately.

The hydraulic shock absorber A is composed of a cylinder 1 and a piston rod 3 which is movably inserted into the cylinder 1 via a piston 2. The cylinder 1 is connected to the vehicle body side via a bracket 4, and the piston rod 3 Is connected to the axle side via a bracket 5. However, the cylinder 1 may be connected to the axle side and the piston rod 3 may be connected to the vehicle body side.

The cylinder 1 is divided into a piston side oil chamber 6 and a rod side oil chamber 7 by a piston 2, and the two oil chambers 6 and 7 are provided with ports 8 and 8a provided in the piston 2 and damping valves 9 and 9a. The damping valves 9 and 9a generate expansion-side and compression-side damping forces, respectively, when the expansion / contraction operation is performed.

Similarly, the two oil chambers 6 and 7 are connected to each other through a vertical passage 11 and a horizontal passage 12 which constitute a bypass 10 provided in the piston rod 3, and are vertically movable in a needle shape provided in the bypass 10. The valve 13 adjusts the opening / closing area of the bypass 10 and generates a damping force of expansion / compression according to the opening area during expansion / contraction operation.

The valve 13 is coupled to a control rod 14 that is vertically movably inserted in the piston rod 3, and the outer end of the control rod 14 projects into a damping force adjusting cylinder 15 in the bracket 5.

A damping force adjusting piston 16 is vertically movably inserted into the cylinder 15, and the piston 16 is brought into contact with or joined to the outer end of the control rod 14 and simultaneously works in the vertical direction.

A hydraulic oil source 17 is connected to the back oil chamber 17 of the damping force adjusting piston 16 either directly or via a damping force adjusting sub-cylinder C shown in FIG.

A sleeve 18a is fitted on the outer circumference of the bracket 5, and a vehicle height adjusting cylinder 19 is provided on the outer circumference of the sleeve 18a. In the cylinder 19, an initial adjusting hi-piston 20 is vertically movable. The lower end of the suspension spring 6 is carried on the upper end of the piston 20 via a spring seat 21, and the upper end of the suspension spring 6 is supported by a spring seat 24a provided on the outer periphery of the cylinder 1, The lower end side oil chamber 22 of 20 is connected to a hydraulic pressure source directly or via an initial adjusting sub-cylinder B shown in FIG.

The oil chamber 17 of the damping force adjusting cylinder 15 communicates with the oil chamber 22 of the vehicle height adjusting cylinder 19 via a port 24 formed in the bracket 5. However, when connecting to the damping force adjusting sub-cylinder C of FIG. 2, the oil chamber 17 is connected to the circuit k. The action and effect are the same as in FIG.

[0042]

[Effect of the device]

 According to the present invention, since the hydraulic pressure is introduced from the common hydraulic pressure source to the initial adjustment piston and the damping force adjustment piston, only one hydraulic pressure source and hydraulic circuit are required, the structure is simple, and the initial adjustment and damping are performed. The force adjustment only needs to be done once, the operability is improved, and power consumption can be saved because only one power source such as a motor for driving the hydraulic pressure source is required.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a hydraulic shock absorber according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram.

FIG. 3 is a vertical sectional front view of a hydraulic shock absorber according to another embodiment of the present invention.

[Explanation of symbols]

 1 Cylinder 2 Piston 3 Piston rod 6,7 Oil chamber 8,8a Port 9,9a Damping valve 10 Bypass 13 Valve 14 Control rod 16 Damping force adjusting piston 20 Initial adjusting piston 23 Suspension spring

Claims (1)

[Scope of utility model registration request] 1. A piston rod is movably inserted into a cylinder via a piston, the piston defines two oil chambers in the cylinder, and the piston is provided with a port for opening and closing the two oil chambers and a damping valve. , The piston rod is provided with a bypass that connects the two oil chambers, and a valve that adjusts the opening area of the bypass is provided in the middle of this bypass so that it can be moved up and down.This valve is a control rod inserted in the piston rod. In a hydraulic shock absorber that is vertically moved, a suspension spring is interposed between the outer circumference of the cylinder and the upper part of the piston rod, and one end of the suspension spring is carried by an initial adjustment piston provided on the cylinder side or the piston rod side. A damping force adjusting piston facing the control rod is provided on the outer end of the piston rod to ensure the initial adjustment. A hydraulic shock absorber in which hydraulic pressure is introduced from a common hydraulic source to the leveling piston and damping force adjusting piston.