JPS6332487Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved attitude control device that prevents rolling, or rolling, when a vehicle turns.

As a device for suppressing rolling when a vehicle turns, for example, in Japanese Utility Model Application No. 56-42739, etc., when the steering wheel is operated at a predetermined vehicle speed or higher, the damping force of the hydraulic shock absorber is switched to a higher level, so that the rolling is suppressed to the left or right of the vehicle. A method has been proposed that prevents the tilting.

The lower the damping force generated by the hydraulic shock absorber, the better the ride comfort of the vehicle, and it is preferable to set the damping force as low as possible except when turning as described above. If only the vehicle speed and steering wheel operation are detected, rolling will also occur when the steering wheel is turned sharply when driving at low speeds, or when the steering wheel is turned slightly when driving at high speeds. As a result, the damping force is switched to a higher value even when rolling is not actually occurring, such as when turning the steering wheel slightly at low speeds. There were times when I got caught.

On the other hand, it is possible to detect the lateral acceleration acting on the vehicle using an acceleration sensor and increase the damping force when this acceleration exceeds a predetermined value.
In this case, there is a problem in that lateral acceleration may be detected even when an individual wheel passes over a protrusion, and malfunctions are likely to occur. In order to solve these problems, the present invention is equipped with a switch that detects lateral acceleration, a switch that detects vehicle speed exceeding a predetermined value, and a switch that operates when the steering angle exceeds a predetermined value. We provide an attitude control system that accurately determines vehicle rolling when all switches are activated and switches the damping force to a higher level to prevent malfunctions and reduce ride comfort. The purpose is to

Hereinafter, embodiments of the present invention will be described based on the drawings.

In Figure 1, 1A and 1B are on the front wheel side, 1C,
1D indicates a hydraulic shock absorber on the rear wheel side.

Each of the hydraulic shock absorbers 1A to 1D can control the generated damping force in two stages, high and low, by driving a rotary solenoid 3, as will be described later. The spring constant can be changed by selectively connecting the electromagnetic switching valve 6 to the switching air accumulator 7.

As shown in FIG. 2, the hydraulic shock absorbers 1A to 1D have a piston 12 housed inside a double cylinder with an inner tube 10 and an outer tube 11. A storage chamber C is partitioned.

The piston rod 13 is connected to the vehicle body side, and the outer tube 11 is connected to the axle side.

Although not shown, the piston 12 is equipped with expansion and compression damping valves, and when the piston rod 13 enters and operates on the compression side, the hydraulic oil from the lower oil chamber B is transferred to the expanding upper oil chamber A on the compression side. The piston rod 13 is caused to flow in through the damping valve, and at this time, a predetermined flow path resistance is applied to generate a compression damping force, and at the same time, the piston rod 13
Excess oil corresponding to the inflow volume is transferred to the outer oil storage chamber C.
On the other hand, when the piston rod 13 comes out of the expansion side, hydraulic oil flows from the upper oil chamber A to the expanding lower oil chamber B via the expansion side damping valve to generate a damping force in the same manner as described above.

A passage 15 that communicates the upper and lower oil chambers A and B is formed inside the piston rod 13, bypassing the piston 12, and a switching valve 16 is interposed in the middle of this passage 15.

The switching valve 16 is connected to an operating rod 17 that passes through the piston rod 13 in the axial direction.
The passage 15 is opened and closed by rotating the .

This operating rod 17 is rotationally driven by the aforementioned rotary solenoid 3, and the damping force is relatively increased when the passage 15 is closed compared to when it is open.

The rotary solenoid 3 and the electromagnetic switching valve 6 are
The excitation is controlled by a signal from the drive circuit 20 shown in FIG.

Reference numeral 21 is a steering angle switch (sensor), which is turned on when the steering wheel is rotated left or right by a predetermined angle or more. 2
2 is a vehicle speed sensor that outputs a signal according to the vehicle running speed, and a comparison voltage (V ₁ ) corresponding to a predetermined vehicle speed value.
The outputs are compared by a comparator 23 having a predetermined vehicle speed, and the comparator 23 outputs a signal that turns on at a predetermined vehicle speed or higher.

24 is a switch (acceleration sensor) that detects lateral acceleration and turns on.
It is configured as shown in FIG.

When the outputs of these switches 21, 24 and the comparator 23 are all turned ON, the output of the AND circuit 25 as a rolling determination means is turned ON, and the drive circuit 20 causes the rotary solenoid 3 and the electromagnetic switching valve 6 to receive an exciting current. Output and operate each.

Lateral acceleration switch 24 in FIGS. 4 and 5
A fixed shaft 31 is installed inside a box-shaped body 30, and an eccentric rotor 32 is rotatably supported on this fixed shaft 31 via a bearing bushing (not shown). A pendulum plate 33 is attached to.

At the bottom of the pendulum plate 33, there are left and right stoppers 35.
When the pendulum plate 33 protrudes and swings left and right by a predetermined angle (for example, 10 degrees), it crosses the slit of the light detection means 36 consisting of a light emitting element and a light receiving element, and its output is reversed.

A cover 34 is attached to the surface of the body 30 to accommodate these, and this lateral acceleration switch 2
4 is installed on the vehicle body so that the axis of the fixed shaft 31 is parallel to (coinciding with) the vehicle running direction.

It is constructed as described above, and its operation will now be explained with reference to FIG. 6. If any one of the outputs of the steering angle switch 21, lateral acceleration switch 24, and comparator 23 is OFF, The circuit 25 does not output a rolling determination signal to the drive circuit 20.

In this state, the rotary solenoid 3 is not excited and the damping force is not switched; that is, the switching valve 16 opens the passage 15, and a low damping force is generated with emphasis on riding comfort.

In addition, the air spring electromagnetic switching valve 6 is also located in the position shown in Figure 1, and the left and right hydraulic shock absorbers 1A, 1B, and 1C
The air spring chambers 5 and 1D are communicated with each other and also with the air accumulator 7.

This reduces the spring constant and maintains a soft ride. On the other hand, when the steering angle of the steering wheel and the vehicle speed are above a predetermined value, such as when the vehicle is turning, both the steering angle switch 21 and the comparator 23 are turned ON, and the output of the lateral acceleration switch 24 is also turned ON, the AND circuit 25 outputs a rolling determination signal, whereby the rotary solenoid 3 and the electromagnetic switching valve 6 are energized.

Then, the switching valves 16 of the hydraulic shock absorbers 1A to 1D close the passages 15 and switch the damping force to a higher level, and the air spring chambers 5 are disconnected from each other to increase the spring constant.

As a result, the hydraulic shock absorbers 1A to 1D prevent the vehicle body from tilting to the left or right (although the shock absorbers on the outer side of the rotation actually contribute to preventing the vehicle from sinking),
This ensures running stability when turning.

By the way, according to this embodiment, when the pendulum plate 33 is tilted by more than a predetermined value in accordance with the lateral acceleration, the light detection means 36 detects this, and the switch 24 for detecting the lateral acceleration is turned on and off. Since the output can be taken out at any time, subsequent signal processing can be easily performed, and when the pendulum plate 33 is tilted more than a predetermined amount, the stopper 35 is held against the inner surface of the body 30, so that the output is stabilized.

In addition, the steering angle switch 21 is also turned ON at a predetermined angle.
- OFF, so signal processing is easy as above, and especially if a switch that turns ON at a predetermined vehicle speed or higher is provided in place of the vehicle speed sensor 22, all signals can be processed in an ON-OFF manner, making it less expensive. A digital control system can be constructed.

As described above, according to the present invention, it is possible to accurately determine the rolling state of the vehicle and prevent the tilting of the vehicle body in a responsive manner, thereby increasing the running stability of the vehicle and reducing unnecessary damping during normal operation. Since the force is not increased, the effect is that the riding comfort is not impaired.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of the present invention, Fig. 2 is a sectional view of the hydraulic shock absorber, Fig. 3 is a block diagram of the control system, Fig. 4 is a partially cutaway front view of the lateral acceleration sensor, and Fig. 5 is a cross-sectional view of the hydraulic shock absorber. The vertical sectional view, FIG. 6, is a time chart showing the control operation. 1A to 1D...Hydraulic shock absorber, 3...Rotary solenoid, 5...Air spring chamber, 6...Solenoid switching valve, 7...Air accumulator, 10, 11...
...Tube, 12...Piston, 13...Piston rod, 15...Passage, 16...Switching valve, 17
...Operation rod, 20... Drive circuit, 21... Steering angle switch, 22... Vehicle speed sensor, 23... Comparator, 24... Lateral acceleration switch, 31... Fixed shaft, 32... Eccentric rotor, 33 ...pendulum board, 3
6...Light detection means.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. At least one of the left and right wheels on the front wheel side or the rear wheel side is supported via a hydraulic shock absorber having a switching valve that changes the damping force in response to an external signal. In the vehicle, the vehicle speed detecting means detects that the traveling speed of the vehicle is equal to or higher than a predetermined value, the steering angle detecting means detects that the steering angle of the front wheels is equal to or higher than a predetermined value, and the lateral acceleration of the vehicle body is set to a predetermined value. a lateral acceleration detection means for detecting that the above-mentioned condition is above, a means for determining that the rolling state is present when all of these detection means are activated, and a means for determining a rolling state by increasing the damping force of the hydraulic shock absorber based on the output of the determination means. 1. A vehicle attitude control device comprising: switching means. 2. The lateral acceleration detection means is characterized in that an eccentric rotor is swingably supported inside the body via a shaft, a pendulum plate is provided on the eccentric rotor, and a means for detecting the swing position of the pendulum plate is provided. A vehicle attitude control device according to claim 1 of the utility model registration claim.