JPH0139203Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hydraulic suspension device that uses hydraulic pressure to drive various actuators connected to a suspension body.

[Prior art]

Hydraulic suspension devices have long been used in Europe because of their ability to provide a soft ride, but their use was limited to a limited number of areas.

In recent years, with the advancement of control technology centered on microcomputers and various sensors, this type of technology has come to be incorporated into automobile suspension systems. Systems that can be controlled have already been proposed. In response to this trend, hydraulic suspension devices are once again attracting attention because their characteristics, such as good responsiveness and the ability to obtain high pressure, make them suitable as control media.

This hydraulic suspension device is constructed as shown in FIG. 1 and has three functions: vehicle height adjustment, spring constant adjustment, and damping force adjustment. That is, the hydraulic unit is composed of a pump 1, a motor 2, a filter 3, a tank 4, and a relief valve 5. Pressure oil generated by this hydraulic unit passes through a check valve 6 and is stored in a gas-filled accumulator 7. The pump 1 is repeatedly started and stopped in response to signals from a pressure switch 8 attached to a motor 2 and a gas-filled accumulator 7, thereby maintaining an appropriate hydraulic pressure.

When raising the vehicle height, the solenoid valves (switching valves) 9a and 9c are opened to supply pressure oil to the suspension body (strut) 10, and when lowering the vehicle height, the solenoid valves 9a and 9c are opened. (Switching valves) 9b and 9c are opened to return pressure oil to tank 4. The solenoid valve 9c is provided to prevent rolling.
The valve is closed under normal driving conditions.

In addition, in order to adjust the spring constant of the suspension device, by opening and closing the solenoid valve (switching valve) 11, the gas-filled accumulators 12a, 12
Perform this by changing the volume of the gas chamber in b.

In addition, in order to adjust the damping force of the suspension device, the throttle (orifice, etc.) of the variable throttle valve 13a of the damping force generator 13 consisting of the variable throttle valve (electromagnetic switching adjustment valve) 13a and the check valve 13b is rotated. This is done by adjusting using a latching type solenoid valve, motor, etc. Further, the check valve 13b is provided to change the damping force on the extension side and the contraction side of the suspension body 10.

The switching and adjustment of each actuator such as the electromagnetic valves 9a, 9b, 9c, 11 and the variable throttle valve 13a is performed using various sensors 14 that detect vehicle height, road surface conditions, roll conditions, sudden starts, sudden stops, etc. This is done by a signal from a controller 15 which receives and processes the signal and issues a signal based on the determination result of the running state and driving situation.

Although only the configuration of the front two wheels of the automobile has been described above based on FIG. 1, a similar circuit configuration is adopted for the rear two wheels, and the hydraulic unit serving as the hydraulic pressure supply source is shared.

By the way, in order to fully utilize the functions of the hydraulic suspension device configured as described above, it is extremely important to improve the operational responsiveness of the actuators such as solenoid valves and motors used to perform each of the above adjustments. If this operational response is poor, the riding comfort of the vehicle will be adversely affected.
Therefore, we have created a margin in the capacity of each of the actuators and increased their rated current.
The current consumption is approximately 3 amperes per solenoid valve.
Since there are 5 to 7 electromagnetic valves in this entire device, the current consumption is at least 15 amperes.In particular, the variable throttle valve 13a has a large oil passage opening area, and the oil pressure in the passage is usually several tens of kg/cm. ^2. It reaches a maximum of more than 100 kg/ ^cm2 , so a considerably large driving force is required to electrically operate the valve body.
Each strut 10 consumes current on the order of several amperes. Therefore, the total current consumption of these actuators becomes large, and considering that the allowable current consumption value of an automobile battery is, for example, 60 amperes, it is impossible to increase the current consumption of these actuators very much. .

[Purpose of invention]

The present invention is intended to solve the above-mentioned problems, and its purpose is to provide an economical hydraulic suspension device in which actuators such as switching valves have good responsiveness and consume less power.

[Structure of the idea]

In order to achieve this object, the present invention adopts a configuration in which the switching valve is driven by a hydraulic actuator such as a cylinder mechanism in a low-pressure hydraulic circuit branched from a high-pressure hydraulic circuit.

With the above configuration, the present invention can provide an economical hydraulic suspension device in which actuators such as switching valves have good responsiveness, and the solenoid valve for operating the hydraulic actuator has low pressure and low capacity and low power consumption. can.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. In this embodiment, the same parts as those of the previously proposed hydraulic suspension device shown in FIG. 1 are given the same reference numerals, and their explanation will be omitted. In this embodiment, a pump 1, a motor 2, a filter 3, a tank 4, a relief valve 5, a check valve 6, a gas-filled accumulator 7, a pressure switch 8,
A hydraulic circuit including electromagnetic valves 9a, 9b, 9c, etc. is a high-pressure hydraulic circuit. A solenoid valve (switching valve) 22 is connected to this high-pressure hydraulic circuit via a branch pipe 21. A gas-filled accumulator 23 and a pressure switch 24 are connected to the solenoid valve 22.
These branch pipes 21, solenoid valves 22, gas-filled accumulators 23, pressure switches 24, and the like constitute a low-pressure hydraulic circuit. The solenoid valve 22 of this low pressure hydraulic circuit includes a solenoid valve (first switching valve) 25,
26 is connected to the solenoid valve 25, and the solenoid valve 25 has two cylinder mechanisms 27 and another solenoid valve (first switching valve) 2.
8 are connected. Furthermore, two cylinder mechanisms 29 and another solenoid valve (first switching valve) 30 are connected to the solenoid valve 26 . Solenoid valve 28, 3
0 are connected to the tank 4, respectively. The cylinder mechanisms 27 and 29 each have a switching valve (second switching valve) 11 that controls the linear motion of their piston rods.
a, a generally well-known conversion mechanism (eccentric cam mechanism, crank mechanism, etc.) (not shown) for converting into a switching operation adjustment mechanism for the variable throttle valve (second switching valve) 13c;
The solenoid valve 11a and the variable throttle valve 13c are switched or adjusted via the solenoid valve 11a and the variable throttle valve 13c. Note that the solenoid valves 25, 26, 28, and 30 are electrically connected to the controller 15. These solenoid valves 25, 26, 28, and 30 are used for low oil pressure in this embodiment. Also,
In this embodiment, a damping force generating device 13-1 is configured by a variable throttle valve 13c and a check valve 13b.

[Effect]

Next, the operation of the hydraulic suspension device configured as described above will be explained. The cylinder mechanisms 27 and 29 are normally in a contracted state due to springs inside the cylinders, and the switching valve 11a and the variable throttle valve 13
c is maintained in the state shown in FIG. Pressure oil in the high-pressure hydraulic circuit is stored in a gas-filled accumulator 23 in a low-pressure hydraulic state via the electromagnetic valve 22 by the action of the pressure switch 24 whose set pressure is set to a low pressure. The solenoid valve 25 is activated by the signal from the controller 15.
is switched, low-pressure oil flows into cylinder mechanism 2.
7 is extended, thereby the variable throttle valve 13c
The damping force of the suspension body 10 is adjusted by switching and adjusting. Further, when the solenoid valve 26 is switched by a signal from the controller 15, low-pressure oil causes the cylinder mechanism 29 to extend, thereby switching the solenoid valve 11a and adjusting the spring constant of the suspension body 10. Further, when the solenoid valve 28 is switched by a signal from the controller 15, the pressure oil in the cylinder mechanism 27 is returned to the tank 4, and the cylinder mechanism 27 is compressed, thereby causing the variable throttle valve 1
3c is returned to its original state. Further, when the solenoid valve 30 is switched by a signal from the controller 15,
The pressure oil in the cylinder mechanism 29 is returned to the tank 4,
The cylinder mechanism 29 is contracted, thereby returning the switching valve 11a to its original state.

Here, a large force is required to drive the switching valve 11a and the variable throttle valve 13c, and depending on the solenoid or motor, a considerable amount of power is consumed.
As described above, when the low oil pressure switching valve 11a and the variable throttle valve 13c are operated by low pressure oil pressure via the cylinder mechanisms 29 and 27, the driving oil pressure of the cylinder mechanisms 29 and 27 is the oil pressure of the high pressure hydraulic circuit. It is sufficient that it is about a fraction of that, that is, 10 kg/cm ² or less.

In addition, the strokes of the cylinder mechanisms 27 and 29 required to operate the switching valve 11a and the variable throttle valve 13c are extremely small, so the oil supplied and discharged to and from them only needs to be at a low pressure and a small flow rate. . Therefore,
The excitation current of the solenoid valves 25, 26, 28, 30 for operating the cylinder mechanisms 27, 29 may be 1 ampere or less, and according to the device of this embodiment,
The power consumption of the actuator for adjusting the spring constant and damping force can be reduced to about 1/2 to 1/4 of that of the device proposed above, and the responsiveness of the actuator also uses hydraulic pressure, so the proposed device It can be made much better than the equipment inside.

In the above embodiment, only the switching valve 11a and the variable throttle valve 13c for adjusting the spring constant and damping force are operated by the cylinder mechanisms 29 and 27, but the cylinder mechanisms 29 and 27 are not limited to this. It is also possible to operate the solenoid valves 9a, 9b, 9c by a cylinder mechanism.

In addition, in the above embodiment, the low pressure hydraulic circuit was configured by the branch pipe 21, the solenoid valve 22, the gas-filled accumulator 23, the pressure switch 24, etc., but the low pressure hydraulic circuit is not limited to this, and as shown in FIG. A pressure regulating valve 31 and a relief valve 32 may be connected to a branch pipe 21 branched from a high-pressure hydraulic circuit to maintain the circuit hydraulic pressure leading to the cylinder mechanisms 27 and 29 at a low-pressure hydraulic pressure, and this low-pressure hydraulic circuit Of the elements constituting the pressure regulating valve 31 and the relief valve 32 may be integrated into a composite valve 40 as shown in FIG. To explain this composite valve 40, the main body 41 and lid bodies 41a, 41b
Piping holes 42a, 42b,
42c is formed. The piping hole 42a is connected to a branch pipe 21 branched from the high pressure hydraulic circuit,
The piping hole 42b is connected to the cylinder mechanism 27, 29 side circuit, and the piping hole 42c is connected to the drain circuit. A piston 43 integrated with a poppet 43a is fitted into the housing so as to be biased to the left in FIG. 4 by an adjustment spring 44. 45 is a valve seat of poppet 43a. Since the piston 43 is biased by the adjustment spring 44, the high-pressure hydraulic circuit connected to the piping hole 42a and the piping hole 42b are blocked by the poppet 43a.
The circuit oil pressure on the side of the cylinder mechanisms 27 and 29 connected to can be maintained at a low pressure oil pressure. Also,
When the cylinder mechanisms 27 and 29 are operated and the hydraulic pressure in the cylinder mechanism 27 and 29 side circuits decreases and the hydraulic pressure difference with the high pressure hydraulic circuit increases, the piston 43 resists the force of the adjustment spring 44. 4, and the pressure oil in the high-pressure hydraulic circuit is guided to the cylinder mechanism 27, 29 side circuit, so the oil pressure on the cylinder mechanism 27, 29 side is maintained at a predetermined oil pressure.

The right side portion of the compound valve 40 is configured as a relief valve consisting of a valve 46, an adjustment spring 47, a push rod 48, an O-ring 49, a valve seat 50, an adjustment screw 51, and a lock nut 52. This relief valve has a function of protecting the hydraulic circuits on the cylinder mechanisms 27 and 29 side from an abnormally high hydraulic pressure in the high-pressure hydraulic circuit or from a transient increase in pressure during valve operation.

The apparatus of the embodiment shown in FIG.
The apparatus according to the embodiment shown in FIG. 3 and the apparatus according to the embodiment shown in FIG. 4 are respectively suitable when the amount of oil supplied to the cylinder mechanisms 27 and 29 is relatively small.

[Effect of idea]

As described above, the present invention operates a switching valve using a hydraulic actuator such as a cylinder mechanism in a low-pressure hydraulic circuit branched from a high-pressure hydraulic circuit connected to a suspension body that is telescopically provided between the wheels and the vehicle body. Since it is configured to be driven, the responsiveness of each switching valve etc. can be made extremely good by using hydraulic pressure, and furthermore, the power consumption required for operation is small, and it has effects such as being economical.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram showing an example of the previously proposed hydraulic suspension device, Fig. 2 is a hydraulic circuit diagram showing one embodiment of the present invention, and Fig. 3 is a hydraulic circuit diagram showing another embodiment of the present invention. Part of the hydraulic circuit diagram, FIG. 4 is a vertical sectional view of a composite valve of a pressure regulating valve and a relief valve used in still another embodiment of the present invention. 1... Pump, 7... Gas-filled accumulator, 10... Suspension body, 11a...
Switching valve (second switching valve), 12a, 12b... gas-filled accumulator, 13c... variable throttle valve (second switching valve), 21... branch pipe, 23...
Gas-filled accumulator, 25, 26, 2
8, 30... Solenoid valve (first switching valve), 27, 2
9... Cylinder mechanism, 31... Pressure regulating valve, 32
...Relief valve, 40...Compound valve.

Claims (1)

[Scope of utility model registration request] A hydraulic suspension body provided telescopically between the wheels and the vehicle body, a high-pressure hydraulic circuit connected to the hydraulic suspension body, a low-pressure hydraulic circuit branched from the high-pressure hydraulic circuit, and the low-pressure hydraulic circuit. a first switching valve provided in the first switching valve, a cylinder mechanism connected to the first switching valve and operated by hydraulic pressure supplied via the first switching valve, and a hydraulic suspension of the high pressure hydraulic circuit; a second cylinder provided on the connection side of the cylinder mechanism and actuated by the cylinder mechanism;
A hydraulic suspension device comprising: a switching valve; and a gas-filled accumulator connected to the second switching valve and operated by hydraulic pressure supplied via the second switching valve.