JP3062617B2 - Suspension device - Google Patents

Abstract

PURPOSE:To enable designated ground clearance control and riding comfortableness control with a small number of parts by driving a motor according to a command signal from a controller and directly operating a rack and pinion mechanism to control the increase and decrease of pressure in an actuator. CONSTITUTION:A rack and pinion mechanism 8 comprises a rack portion 8a on the piston rod 12 side and a pinion gear 8b engaged therewith, wherein when a motor 9 is normally rotated according to a command from a controller C, an actuator 1 is let have a tendency of contraction to lower the pressure in the actuator 1. When the motor 9 is reversed, the actuator is let have a tendency of elongation to lower the pressure in the actuator 1. On the other hand, while the drive of the motor 9 is paused, designated damping force is generated when the operating oil passes through a damping valve 13a of a piston 13 so that the actuator 1 is allowed to have a shock absorber function.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a suspension apparatus which is most suitable for use in an active suspension or the like as a vehicle suspension system.

[0002]

2. Description of the Related Art There have conventionally been various proposals for a suspension apparatus used for an active suspension or the like as a suspension system of a vehicle. For example, in the suspension apparatus shown in FIG. Hydraulic oil from a hydraulic source 2 is applied to an actuator 1 comprising a hydraulic cylinder disposed between an axle A (T is a tire) and a vehicle body B via a control valve 3 (only one wheel is shown in the drawing). The pressure in the actuator 1 is increased by the supply, and the hydraulic pressure from the actuator 1 is controlled by the control valve 3.
, The pressure in the actuator 1 is reduced to control the vehicle height in each part of the four wheels of the vehicle.

The actuator 1 is provided with a gas spring 1a and a damping valve 1b while a suspension spring (not shown) is interposed (see FIG. 8).

The control valve 3 is configured to be activated so-called by a command signal from the controller C. The controller C includes a sensor C1 mounted on the vehicle body B for detecting longitudinal acceleration and lateral acceleration, and a sensor C1. Assuming that signals from the sensor C2 for detecting acceleration are respectively input,
The detection values from the sensors C1 and C2 are calculated and processed by the controller C and output as command signals to the control valve 3.

On the other hand, as a specific hydraulic circuit for the suspension device, for example, one having a configuration as shown in FIG. 3 is proposed.

That is, the hydraulic circuit comprises a hydraulic source 2 and a control valve 3.
And the control valve 3 and the tank 4
Are communicated through a discharge passage 6 and the control valve 3 and the actuator 1 are communicated through an oil passage L.

[0007] In the drawings, only the front side of the vehicle is shown, and the rear side of the vehicle has the same configuration, and is not shown.

The supply passage 5 has a flow control valve 5a,
A fail-safe valve 5b and an accumulator 5c are arranged in series, and an operation check valve 6
a, and a relief valve 7a is disposed in a communication path 7 that connects the supply path 5 and the discharge path 6, and a fail-safe valve 3a is disposed in parallel with the control valve 3. It is going to be.

Therefore, according to the conventional suspension device controlled by the above-mentioned hydraulic circuit, the sensors C1 and C1 for detecting the state of the vehicle appearing on the vehicle body B while traveling on the road surface.
2 is input to the controller C, and is output to the control valve 3 as a signal processed based on a location preset in the controller C. The operation of the control valve 3 causes the actuator 1 to operate. , The vehicle height at each part of the four wheels of the vehicle can be actively controlled according to the condition of the traveling road surface.

[0010]

However, in the above-mentioned conventional suspension device, there is a fear that improvement in versatility cannot be expected.

That is, in the above-mentioned conventional suspension device, in addition to the control valve 3 for actively controlling the height of the vehicle according to the condition of the running road surface, the engine is turned off for a long period of parking or the like. A check valve and an operating check valve 6a for maintaining the vehicle height at the time are required, and a fail-safe valve 5 for maintaining the vehicle height at the time of fail-safe.
b and the fail-safe check valve 3a are required.

Therefore, the increase in the number of assembling steps, the increase in the size and the weight of the entire device, and the increase in the production cost due to the large number of devices, and the increase in the production cost, are also caused. Since the above devices are connected by piping, a large number of assembling steps are required when the device is mounted on a vehicle, and improvement in versatility cannot be expected.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention not only to enable so-called active height control but also to require valves only for that purpose. It is an object of the present invention to provide a suspension device that can maintain the vehicle height during parking or fail-safe operation, is simple in structure, is excellent in mountability, and is inexpensive, and is optimal for expecting its versatility to be improved. .

[0014]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, an actuator according to the present invention is provided in each of four parts of a vehicle, the upper end being connected to a vehicle body and the lower end being connected to an axle side. The suspension device is formed so as to be able to control the height of each of the four wheels of the vehicle by controlling the expansion and contraction of the vehicle, and the actuator slides in the cylinder while partitioning one oil chamber and the other oil chamber in the cylinder. A double-acting double-rod cylinder having a piston rod having an intermediate portion connected to the piston and both ends protruding outward from both ends of the cylinder, while one end of the piston rod rod is provided on the vehicle body side or the axle side. And the other end of the piston rod rod is connected to a cylinder via a rack and pinion mechanism.

It is assumed that a motor as a drive source driven by a command signal from a controller is connected to the cylinder, and the rack and pinion mechanism is operated by the motor.

The rack and pinion mechanism includes a rack portion on the piston rod side and a pinion gear on the motor side meshing with the rack portion. If necessary, the rack and pinion mechanism has a reduction mechanism between the motor and the pinion gear. And

[0017]

Therefore, when the vehicle height at each part of the four wheels of the vehicle is changed in accordance with the condition of the traveling road surface, the condition of the vehicle height change is determined by each sensor for detecting longitudinal acceleration, lateral acceleration, and vertical acceleration of the vehicle body. While being detected, detection signals from the respective sensors are input to the controller.

The controller performs arithmetic processing on each of the above-mentioned signals based on a preset location, and outputs these signals as command signals to a forward / reversely rotatable motor as a drive source of the rack and pinion mechanism.

The rack and pinion mechanism includes a rack portion on the piston rod side, a pinion gear meshing with the rack portion,
For example, when the motor is rotated forward, the actuator has a tendency to contract and lower the pressure on the actuator.

Also, when the motor is reversed, it tends to extend the actuator, reducing the pressure at the actuator.

That is, it is possible to control the pressure of the actuator by selecting the normal rotation or the reverse rotation of the motor via the controller.

On the other hand, while the driving of the motor is stopped, the actuator can be expanded and contracted. At this time, the one oil chamber and the other oil chamber are communicated with each other via a damping valve provided on the piston. A predetermined damping force is generated when the oil passes through the damping valve, so that the actuator can have a shock absorber function.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. The suspension device according to the present invention is arranged at each of four parts of a vehicle, and has an upper end connected to a vehicle body B and a lower end connected to an axle A. Having an actuator 1 to be
The actuator 1 is formed so as to be able to control the height of each part of the vehicle by controlling the expansion and contraction of the actuator 1.

Accordingly, the present invention will be described below while describing the structure of the actuator 1 according to the present invention.

As shown in FIG. 1, an actuator 1 according to the present invention is formed such that both ends of a piston rod 12 inserted into a cylinder 11 project outside from both ends of the cylinder 11. A first oil chamber R1 and a second oil chamber R2 filled with hydraulic oil in the cylinder 11 are defined by a piston 13 which is connected to an intermediate portion of the piston rod 12 and is slidably housed in the cylinder 11. And a double-rod double-acting cylinder.

In this embodiment, one end of the piston rod 12, which is the left end in the figure, is connected to the vehicle body B, while the piston rod 1, which is the right end in the figure, is connected.
The other end, which is the lower end of the cylinder 11, is connected to the cylinder 11 via a rack and pinion mechanism 8, that is, the housing 11 a connected to the lower end of the cylinder 11.
Is connected to the axle A via an eye 11b connected to the lower end thereof.

The actuator 1 is disposed on each of the four wheels of the vehicle under the presence of the suspension spring 1c. In this embodiment, the actuator 1 is provided between one end of the piston rod 12 and the vehicle body B. The load cell C3 is provided, and is set so that the pressure in the actuator 1 can be detected.

The rack-and-pinion mechanism 8 includes a rack portion 8a formed on the piston rod 12 side and a pinion gear 8b meshed with the rack portion 8a. 8b is configured to be rotated.

A speed reduction structure composed of a gear 10 is disposed between the motor 9 and the rack and pinion mechanism 8, and the gear 10 has a gear 9b held on an output shaft 9a of the motor 9. Are engaged.

The motor 9 is set so as to be able to rotate forward and backward by a command signal from the controller C. The controller is mounted on the vehicle body B and detects longitudinal acceleration and lateral acceleration in the same manner as in the above-described conventional example. Signals from the sensor C1 and the sensor C2 for detecting the vertical acceleration, respectively, and in this embodiment, the load cell C3
Is also input.

On the other hand, the piston 13 is
It has a damping valve 13a that enables communication between the one oil chamber R1 and the other oil chamber R2 that are defined therein, and that generates a predetermined damping force when hydraulic oil passes therethrough.

Therefore, in the above-described embodiment, for example, when the motor 9 is rotated forward, the rack 8a moves rightward in the drawing, and the piston rod 12 moves in a so-called contraction direction. Therefore, the actuator 1 tends to contract and the pressure in the actuator 1 decreases.

When the motor 9 is rotated reversely,
When the rack portion 8a moves to the left in the drawing, the piston rod 12 moves in a so-called extension direction, and the actuator 1 tends to extend, and the pressure in the actuator 1 increases.

That is, the motor 9 via the controller C
, The pressure in the actuator 1 can be controlled to be high or low.

The controller C includes sensors C1 and C1 for detecting the condition of the vehicle appearing on the vehicle body B traveling on the road.
2 and the detection signal from the load cell C3 are output to the motor 9 as signals processed on the basis of what is preset in the controller C.

As a result, the pressure in the actuator 1 is controlled by the selected rotation of the motor 9,
The vehicle height at each part of the four wheels of the vehicle is controlled so-called active according to the condition of the traveling road surface.

On the other hand, when the rotation of the motor 9 via the controller C is stopped, the pressure in the actuator 1 does not fluctuate, so that the actuator 1 expands and contracts freely.

At this time, the one oil chamber R1 in the cylinder 11
And the other oil chamber R2, hydraulic oil flows through each other through a damping valve 13a provided on the piston 13, and a predetermined damping force is generated when the hydraulic oil flows through the damping valve 13a. Will be generated.

The suspension of the rotation of the motor 9 via the controller C is also caused at the time of fail-safe. Therefore, at the time of fail-safe, the actuator 1 can be provided with the above-described shock absorber function. Become.

Further, at the time of fail-safe, the suspension spring 1c interposed in the actuator 1 bears the load of the vehicle body, so that there is no fear that the vehicle may bottom out on the road surface.

In the embodiment described above, the actuator 1 is arranged between the vehicle body B and the axle A in a so-called upright state. However, according to the object and configuration of the present invention, the cylinder 11 is The piston rod may be connected to the vehicle body B and the axle A may be connected to the axle A.

When the actuator 1 is arranged in an inverted state, the motor 9 side is provided on the vehicle body B side, so that the durability of the actuator 1 against road surface vibration is improved. is there.

[0043]

As described above, according to the present invention, for controlling the pressure of the actuator in accordance with the condition of the road surface on which the vehicle travels, the condition of the vehicle body is detected by the sensors provided on the vehicle body. This is input to the controller, and the motor is driven by a command signal from the controller to directly operate the rack-and-pinion mechanism to control the pressure in the actuator, so that the pressure control in the actuator is reliably executed. Needless to say, when the motor is not driven, one of the oil chambers and the other oil chamber in the cylinder constituting the actuator are circulated through a damping valve provided on the piston so that the actuator has a shock absorber function. The vehicle height control and ride comfort control can be performed with a small number of parts. Score in the can because the structure easily allows reduction and weight reduction and cost cost reduction of assembly process,
Numerous effects are achieved, such as being inexpensive and excellent in mountability, and optimal for expecting improvement in versatility.

[Brief description of the drawings]

FIG. 1 is a view showing a suspension device according to an embodiment of the present invention.

FIG. 2 is a view showing a conventional suspension device.

FIG. 3 is a diagram showing a hydraulic circuit used for a conventional suspension device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Actuator 8 Rack and pinion mechanism 11 Cylinder 12 Piston rod 13 Piston A Axle B Body R1 One oil chamber R2 The other oil chamber

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B60G 17/015

Claims (1)

(57) [Claims] 1. A vehicle height control in each of the four wheels of a vehicle by controlling the expansion and contraction of an actuator disposed in each of the four wheels of the vehicle and having an upper end connected to the vehicle body and a lower end connected to the axle side. In the suspension device formed, an intermediate part is connected to a piston which slides in the cylinder while an actuator partitions one oil chamber and the other oil chamber in the cylinder, and both ends of the piston are externally connected to both ends of the cylinder. A double-rod double-acting cylinder having a piston rod protruding from the other end is connected to one of the vehicle body side and the axle side, and the other end of the piston rod rod is connected to a rack and pinion. A suspension device which is connected to a cylinder via a mechanism.