JPH0585365B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a vehicle height adjustment device for an automobile.

(Prior Art) The above vehicle height adjustment device includes a fluid actuator that is located between the vehicle body and the wheels and supports the vehicle body;
In order to select the vehicle height, a vehicle height adjustment valve that supplies or discharges pressure fluid from a pump to this fluid actuator is used, and a vehicle height signal indicating the actual vehicle height is compared with a target vehicle height signal. Based on the above, the vehicle is provided with a controller that switches and controls the vehicle height adjustment valve, and a vehicle height detection device is provided to supply the vehicle height signal to the controller.

This type of vehicle height detection device is, for example,
As disclosed in Publication No. 47108, a rotating shaft,
A vehicle height sensor equipped with a rotation support means that generates an electric signal according to the rotation angle of the rotation shaft is fixed to the vehicle body, and the rotation shaft of the vehicle height sensor and the suspension member are connected by a link mechanism. The vehicle height is detected by optically detecting the amount of rocking of the link mechanism when the vehicle height changes as the rotation angle of the rotating shaft. However, when trying to improve the detection accuracy of this vehicle height detection device, the mechanism of the detection device becomes complicated, causing problems in cost and size.

(Objective of the Invention) Therefore, it is an object of the present invention to provide a vehicle height adjustment device for an automobile that is simple in structure and capable of accurately detecting the vehicle height.

(Structure of the Invention) The present invention provides a vehicle height control system that adjusts the vehicle height by supplying and discharging pressurized fluid from a pump to and from a fluid actuator that is located between the vehicle body and the wheels and supports the vehicle body by switching a vehicle height adjustment valve. The adjusting device is based on a vehicle height sensor that detects a vehicle height and outputs a digital data signal according to the vehicle height, and a comparison between the digital data signal from the vehicle height sensor and a target vehicle height signal. , a controller that switches and controls the vehicle height adjustment valve, and the vehicle height sensor has at least two codes, a first vehicle height signal having a relatively long interval between each code; code, and outputs a second vehicle height signal with a relatively short interval between each code, and the controller:
In response to the first vehicle height signal, a plurality of absolute vehicle height positions are determined, and in response to the second vehicle height signal, the direction of relative displacement of the vehicle body and wheels from the absolute vehicle height position is determined. It is characterized by certain things.

(Operations and Effects of the Invention) In the vehicle height adjustment device of the present invention described above, the detection device that emits the first and second vehicle height signals is used as the vehicle height detection device, and when adjusting the vehicle height to a desired vehicle height value, The first vehicle height signal is used to quickly adjust the vehicle height, and after the desired vehicle height is reached, the second vehicle height signal is used to make fine adjustments to the vehicle height. requires at least 2 bits, and therefore, the vehicle height detection device has a simple and inexpensive structure, and yet the vehicle height can be adjusted with high precision. Therefore, even if the vehicle height drops due to, for example, a slight oil leak, this can be detected and oil can be replenished to return the vehicle to its original height.

(Embodiments) Hereinafter, a vehicle height adjustment device for an automobile according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing a vehicle height adjustment device for an automobile according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 indicates a vehicle body, and reference numeral 2 indicates a wheel, and this wheel 2 is rotatably supported by a wheel support member 3. This wheel support member 3 has a lower end 3a connected to the frame 1a of the vehicle body 1 via a lower arm 4, and
The upper end portion 3b is connected to the vehicle body 1 via a strut 5 as a fluid actuator for adjusting vehicle height, and the lower arm 4 regulates the movement of the wheel 2 in the vehicle width direction, and also suppresses the vertical vibration of the wheel 2. It is designed to be absorbed by strut 5.

As shown in FIG. 2, the strut 5 includes a cylinder 6 with an open upper end and a
A first hydraulic chamber 6a and a second hydraulic chamber 6 are arranged vertically inside the cylinder 6 and are slidably arranged inside the cylinder 6.
The piston 7 is connected to the piston 7 and projects upward from the upper end opening of the cylinder 6. The lower end of the cylinder 6 is connected to the upper part of the wheel support member 3 via a bracket 9, while the upper end thereof is connected to the vehicle body 1 via a mount rubber 10. Further, the first and second hydraulic chambers 6a and 6b of the cylinder 6 are communicated with each other through an orifice 11 formed in the piston 7 so that oil can enter and exit from each other. When the wheel 5 expands and contracts, that is, when the piston 7 slides vertically within the cylinder 6, the vertical vibration of the wheel 2 is damped by the effect of delaying oil inflow and outflow at the orifice 11.

In FIG. 1, reference numeral 12 designates an accumulator that performs a spring action, and the interior of this accumulator 12 is divided by a diaphragm 12c into a gas chamber 12a and a hydraulic chamber 12b that oppose each other.
The gas chamber 12a is filled with nitrogen gas or the like. Hydraulic chamber 12b of this accumulator 12
is communicated with the second hydraulic chamber 6b of the cylinder 6 of the strut 5 via a communication conduit 13 and a hydraulic passage 14 formed in the piston rod 8 of the strut 5. This accumulator 12 transfers the pressure generated in the second hydraulic chamber 6b to the first hydraulic chamber 6a and transmitted to the hydraulic chamber 12b to the gas chamber 12.
It is configured to function as a gas spring that is supported by the compressive elasticity of the gas sealed in 2a. Further, a damping force valve 15 is provided in the middle of the communication pipe 13, and the damping force is made variable by adjusting the opening of this damping force valve 15.

The above-mentioned accumulator 12 of the above-mentioned communication pipe line 13
The right front wheel side pressure oil supply path 1 is located between the damping force valve 15 and the damping force valve 15.
6 is connected, and this pressure oil supply path 16 is connected to 4.
It is connected to one discharge port of a flow dividing valve 17 having two discharge ports. The other three discharge ports of this flow dividing valve 17 include a left front wheel side pressure oil supply path 18 which has the same function as the right front wheel side pressure oil supply path 16, a right rear wheel side pressure oil supply path 19, and a left rear wheel side pressure oil supply path. Supply paths 20 are connected to each other. The diversion valve 17 is connected by a pressure oil supply path 21 to an oil pump 22 that serves as a hydraulic drive source for the strut 5, which is a fluid actuator, and transfers the pressure oil from this pump 22 to the four pressure oils. The flow is divided into supply channels 16, 18, 19 and 20. The oil pump 22 is connected to the engine E via a drive belt 23 and is driven to follow the rotation of the engine E.

The pressure oil supply path 16 is provided with a leveling valve 24 which is an electromagnetic valve, and this leveling valve 24 supplies the pressure oil from the diversion valve 17 to the strut 5 while adjusting the amount thereof, and increases the vehicle height. This is to adjust the A drain passage 25 is connected to the pressure oil supply passage 16 between the diversion valve 17 and the leveling valve 24, and this drain passage 25 is provided with an unload valve 26 which is a solenoid valve.

The leveling valve 24 and unloading valve 26 are
Both are connected to a controller 27 composed of a microcomputer, etc., and the duty ratio is controlled by this controller 27, so that the leveling valve 24 is activated at the pulse duration _t1 of the pulse time T as shown in FIG. is opened, the unload valve 26 is closed, and the remaining time
At _t2 , unload valve 26 is configured to open and leveling valve 24 is configured to close. With this configuration, part of the pressure oil supplied from the diversion valve 17 is supplied to the strut 5 in an amount corresponding to time _t1 , while the remainder is drained in an amount corresponding to time _t2 . be done. The controller 27 is also connected to the damping force valve 15, and adjusts the opening degree of the damping force valve 15 as necessary to adjust the damping force.

The controller 27 includes a manual switch 2 that outputs a target vehicle height signal _S0 indicating a desired vehicle height.
8, and a vehicle height detection device 30 that detects the actual vehicle height and outputs a vehicle height signal _S1 indicating the detected vehicle height. The controller 27 receives the target vehicle height signal S ₀ and the vehicle height signal S ₁ and controls the opening of the leveling valve 24 so that the vehicle height reaches the target vehicle height, especially when the vehicle is loaded or rolled. , controls the supply of pressure oil to the strut 5. With this, the desired vehicle height is always achieved.

Next, details of the vehicle height detection device 30 will be explained with reference to FIG. 4 and subsequent figures. Note that this detection device 30
will be described assuming that three vehicle height positions, normal position, high position, and low position are detected.

FIG. 4 is a diagram showing the main parts of the vehicle height detection device 30, which has a rotating shaft 31 that rotates when the vehicle body 1 moves relative to the wheels 2. ing. A rotary disk 32 is fixed to this rotary shaft 31 and rotates at the same time as the shaft 31 rotates. This disk 32
First to fourth angular position detection patterns 33 to 36, which are made up of openings and non-openings for indicating the rotational angular position of the disk 32, that is, the vehicle height, are provided on the peripheral edge of the disc 32. As will be explained later, the first and second patterns 33 and 34
is for detecting the absolute value of the vehicle height,
The third and fourth patterns 35 and 36 are for detecting relative values. The above disk 32
on one side of the above-mentioned first to fourth patterns 3
First to fourth light sources 37 to 40 are provided to irradiate light to the disks 3 to 36, respectively, and the light sources 3 to 40 are provided on the other side of the disk 32.
First to fourth light receiving elements 41 to 44 are provided to receive the light from the patterns 7 to 40 when it passes through the openings of the patterns 33 to 36, respectively. These light receiving elements 41 to 44 are
It is assumed that an ON signal is output to the controller 27 when light is received.

Next, the effects of the patterns 33 to 36 will be explained with reference to FIG. Note that FIG. 5 shows each of the above patterns in a straight line. Further, hereinafter, the light-transmitting portion of each pattern will be referred to as an ON portion, and the light-blocking portion will be referred to as an OFF portion.

The first to fourth patterns 33 and 36
are the ON part and the ON part each having substantially the same width.
It is made by repeating the OFF part and arranging it,
The first and second patterns 33 and 34 have a relatively large width between the ON part and the OFF part, and the width of the third and fourth patterns 35 and 36 have a relatively small width between the ON part and the OFF part. in
The ON part and the OFF part are arranged with a phase difference of half a width from each other.

The first and second patterns 33 and 34 are arranged so that the second pattern 34 does not change and the first pattern 3
3 indicates the normal vehicle height position when it changes from the OFF part to the ON part or vice versa, and when the first pattern 33 does not change at the ON part, the second pattern 34
indicates a low vehicle height position when the pattern changes from the OFF section to the ON section, while the first pattern 33 remains unchanged at the OFF section and the high vehicle height position is indicated when the second pattern 34 changes from the ON section to the OFF section. shall be shown.
The third and fourth patterns 35 and 36 are
The switching section between the ON section and the OFF section of the first or second pattern is located at an intermediate position between the overlapping ON sections, that is, as shown in FIG. 5.

Next, vehicle height detection and vehicle height adjustment in the above embodiment will be explained with reference to FIG. In addition, in the following explanation, unlike the actual case,
Assume that the pattern is fixed and the spots of light from light sources 37-40 (shown with the same number as the light source with a lowercase alphanumeric character) move, and that the vehicle height is at normal vehicle height, so that each spot has a symbol. They are located at positions 37a, 38a, 39a, and 40a.

When adjusting the vehicle height by supplying pressure oil from the normal vehicle height position, for example, absolute adjustment is performed while detecting the position using the first and second patterns 33, 34. In this case, when the spot gradually moves to the right and reaches the positions indicated by symbols 37b and 38b, the second pattern 34 changes from the ON part to the OFF part, so the controller 27 adjusts the vehicle height to the target high vehicle height position. Detects that it is set to . Then, the controller 27 performs vehicle height adjustment based on position detection using the first and second patterns 33 and 34, that is, absolute vehicle height adjustment, to relative vehicle height adjustment based on position detection using the third and fourth patterns 35 and 36. Switch to

If pressure oil is continued to be supplied from the point at which the absolute vehicle height adjustment described above is completed, the positions of spots 39d and 40d will further move to the right, and when they move to positions 39c and 40c, the fourth pattern 36 will turn ON. Changes from part to OFF part. Then controller 2
7 detects that the vehicle height has increased by a predetermined value from the target high vehicle height position, and this time stops the supply of pressure oil;
Drain. The spot gradually moves to the left, but when it drains too much and moves to the positions 39d and 40d, the third pattern 35 moves from the ON part.
Changes to OFF part. At this time, the controller 27
determines that the vehicle height has fallen by a predetermined value from the target high vehicle height position, and restarts supply of pressure oil. By repeating the above steps, after setting the vehicle height to the target vehicle height, it becomes possible to maintain the vehicle height almost at this set vehicle height at all times. Vehicle height adjustments other than those described above can be performed in the same manner as described above, and therefore descriptions of other modes of vehicle height adjustment will be omitted.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a vehicle height adjustment device according to an embodiment of the present invention, FIG. 2 is a detailed sectional view of a strut, FIG. 3 is a diagram showing pulses used to control a leveling valve, and FIG. Figure 4 is a schematic perspective view of the vehicle height detection device used in the present invention, and Figure 5 is a schematic perspective view of the vehicle height detection device used in the present invention.
5 is an explanatory diagram showing main parts of the vehicle height detection device shown in FIG. 4. FIG. 1...Vehicle body, 2...Wheels, 5...Struts,
25...Leveling valve, 27...Controller,
28...Manual switch, 30...Vehicle height sensor, 33, 34, 3536...First, second, third, fourth pattern.

Claims (1)

[Claims] 1 A vehicle height adjustment device that adjusts the vehicle height by supplying and discharging pressurized fluid from a pump to a fluid actuator that is located between the vehicle body and the wheels and supports the vehicle body by switching the vehicle height adjustment valve. a vehicle height sensor that detects the vehicle height and outputs a digital data signal corresponding to the vehicle height, and switches the vehicle height adjustment valve based on a comparison between the digital data signal from the vehicle height sensor and a target vehicle height signal. Equipped with a controller to control the
The vehicle height sensor has at least two codes, a first vehicle height signal with a relatively long interval between each code, and a first vehicle height signal with at least two codes and a relatively short interval between each code. The controller outputs a second vehicle height signal, and upon receiving the first vehicle height signal, the controller determines a plurality of absolute vehicle height positions, and upon receiving the second vehicle height signal, determines the absolute vehicle height position. A vehicle height adjustment device for an automobile, characterized in that the device determines the direction of relative displacement between a vehicle body and wheels from a position.