JPH0534962Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an electronically controlled suspension device that does not perform vehicle body posture control when a high vehicle height is selected.

2. Description of the Related Art An electronically controlled suspension device has been proposed which improves riding comfort by electronically controlling the damping force of the shock absorber and the spring constant of the air spring chamber of each suspension unit of an automobile. In addition, in such an electronically controlled suspension device, the amount of compressed air in the air spring chamber can be adjusted to automatically adjust the vehicle height to a high vehicle height, low vehicle height, or the vehicle height. It is desired to more effectively prevent the vehicle body from tilting during sharp turns, for example, by performing air supply and exhaust. However, when the vehicle height is selected to be high, the vehicle speed is low and the vehicle is traveling on a rough road. Since this requires a large amount of energy, it is preferable not to perform vehicle attitude control.

This idea was made in view of the above points,
The object of the present invention is to provide an electronically controlled suspension device that does not perform vehicle body posture control when a high vehicle height is selected.

Hereinafter, an electronically controlled suspension device according to an embodiment of the invention will be described with reference to the drawings. In Figure 1, S _FR is a suspension unit for the right front wheel of a car, S _FL is a suspension unit for the left front wheel, S _RR is a suspension unit for the right rear wheel, and S _RL is a suspension unit for the left rear wheel. . Each suspension unit
Since S _FR , S _FL , S _RL , and S _RR have the same structure, only the structure of the suspension unit S _RL is shown. The suspension unit S _RL has a main air spring chamber 11, a sub air spring chamber 12, and a shock absorber 1.
3. Consists of a coil spring (not shown) used as an auxiliary spring. Further, 14 is an actuator for switching the damping force of the shock absorber 13 between hard and soft, and 15 is a bellows. Note that the actuator 14
The main air spring chamber 11 and the sub air spring chamber 12 are
Communication and non-communication are controlled, and the air spring constant is switched between hard and soft.

Further, 16 is an air cleaner. The air sent from the air cleaner 16 is sent to the dryer 18 via an outside air cutoff solenoid valve 17. The air dried by the dryer 18 is compressed by a compressor 19 and stored in a reserve tank 21 via a check valve 20. Note that 191 is a compressor relay, and this relay 191 is controlled by a signal from a controller 36, which will be described later. The reserve tank 21 has air supply solenoid valves 221 to 224.
The main and auxiliary air spring chambers 1 of each suspension unit S _RL to S _FL are connected via the air supply piping 23 in which the
1 and 12. In addition, the main and sub air spring chambers 11 and 12 of the suspension units S _RL and S _RR
are connected by a communication pipe 25 in which a communication solenoid valve 241 is installed, and the main and sub air spring chambers 11 and 12 of the suspension units S _FL and S _FR are
are connected by a communication pipe 26 in which a communication solenoid valve 242 is interposed. In addition, the main and auxiliary air spring chambers 11 and 12 of each of the suspension units S _RL to S _FL are connected to exhaust solenoid valves 271 to 271.
274 is installed, the exhaust pipe 28, the check valve 29, the dryer 18, and the solenoid valve 1.
7. It is released to the atmosphere via the air cleaner 16. A piping 31 in which a solenoid valve 30 for selecting an air supply side flow path is interposed is arranged in parallel with the air supply piping 23 . Furthermore, a pipe 33 in which an exhaust side flow path selection solenoid valve 32 is interposed is arranged in parallel with the exhaust pipe 28 . In addition, the air supply pipe 23
A hard/soft switching solenoid valve 34 is interposed between the actuator 14 and the actuator 14.
Further, the pressure of the compressed air stored in the reserve tank 21 is detected by a pressure switch 35. The detection signal of this pressure switch 35 is sent to a controller 36. A pressure switch 37 is connected to the communication pipe 25 and detects the internal pressure of the main and auxiliary air spring chambers 11 and 12 of the lower suspension units S _RR and S _RL . A detection signal from this pressure switch 37 is sent to the controller 36. Further, 38F is a front vehicle height sensor 38 that is attached to the lower arm 39 on the front right side of the vehicle and detects the front vehicle height (front vehicle height) of the vehicle.
R is a rear vehicle height sensor that is attached to a lateral rod 40 on the rear left side of the automobile and detects the rear vehicle height. Above vehicle height sensor 38F, 38
A vehicle height detection signal output from R is input to the controller 36. Above sensor 38F, 38R
One of the Hall IC elements and magnets is attached to the wheel side and the other to the vehicle body side to detect the distance from the normal vehicle height level and the low or high vehicle height level. Further, 41 is a vehicle speed sensor that detects the vehicle speed, and a detection signal outputted from this vehicle speed sensor 41 is inputted to the controller 36. Furthermore, 42 is a steering wheel angle sensor that detects the steering angle of the steering wheel 43, and this sensor 42 outputs a steering wheel steering angle detection signal to the controller 36. Further, reference numeral 44 denotes an acceleration (G) sensor as a vehicle body posture sensor for detecting changes in the posture of the vehicle body, and this acceleration sensor 44 is designed to detect changes in the posture of the vehicle body such as pitch, roll, and yaw on the automobile spring. For example, when there is no acceleration, the weight is in a hanging state, and the light from the light emitting diode is blocked by the shielding plate and does not reach the photodiode, so that it is detected that there is no acceleration. And the acceleration is back and forth,
When acting horizontally or vertically, the weight tilts or moves, and the acceleration state of the vehicle body is detected. Furthermore, 45 is a vehicle height selection switch that sets the vehicle height to high vehicle height (HIGH), low vehicle height (LOW), or vehicle height adjustment (AUTO), and 46 is a vehicle height selection switch that selects to perform attitude control to prevent the vehicle from rolling. This is an attitude control selection switch. The signals of the switches 45 and 46 are transmitted to the controller 36.
is input. Further, numeral 47 is an oil pressure switch that detects whether the oil pressure of the engine oil has reached a predetermined value and the amount of oil pressure, and the oil pressure detection signal output from this oil pressure switch 47 is input to the controller 36. A brake switch 48 detects the depression and amount of depression of the brake, and its detection signal is input to the controller 36. Further, reference numeral 49 denotes an accelerator opening sensor that detects the opening of the accelerator, and an accelerator opening signal outputted from this sensor 49 is input to the controller 36. Furthermore, 50 is an engine rotation speed sensor that detects the engine rotation speed, and this sensor 50 outputs an engine rotation speed signal to the controller 36. Further, 51 is an ignition key, the operation number of which is output to the controller 36. 5
A gear position sensor 2 detects the gear position, and this sensor 52 outputs a gear position signal to the controller 36.

In addition, the above-mentioned solenoid valves 17, 221 to 2
24, 271 to 274, 30, and 34 are normally closed valves, and the solenoid valves 241 and 242 are normally open valves.

Next, the operation of one embodiment of the invention constructed as described above will be explained. When the ignition key is turned on, the controller 36 executes the process shown in the flow chart shown in FIG. In step S1 of Fig. 2, the vehicle is prevented from rolling.
In other words, it is determined whether roll control is necessary. This is to determine whether roll control is necessary, for example, when the lateral acceleration detected by the acceleration sensor 44 is equal to or greater than a predetermined value. If it is determined “YES” in step S1, step S2
Then, it is determined whether the high vehicle height (HIGH) is selected by the vehicle height selection switch 45.
If the determination in step S2 is "NO", the process proceeds to step S3, where roll control is performed to suppress changes in the vehicle height attitude. This supplies air to the main and auxiliary air spring chambers 11 and 12 of the right suspension units S _FR and S _RR and the left suspension units S _FL and S _RL , and supplies air to the main and auxiliary air spring chambers 11 and 12 of the right suspension units S FR and S RR and the left suspension units S FL and S RL. By exhausting air from the auxiliary air spring chambers 11 and 12, roll control is performed to suppress changes in the attitude of the vehicle body. Next, the process proceeds to step S4, where the flag _F1 in the controller 36 is set to "1".
On the other hand, if the determination in step S2 is ``YES'', the process proceeds to step S5, where it is determined whether or not the attitude control function has been selected by the attitude control selection switch 46. If the determination in step S5 is "NO", the process advances to step S6 and the roll control is stopped. In other words, air supply solenoid valve 2
21~224, exhaust solenoid valve 271~
274 is closed. Then, the process returns to step S1. By the way, in this step S1, "NO"
If it is determined that
It is determined whether <sub>F1</sub> is set to "1". If the determination in step S7 is ``YES'', the process proceeds to step S8, where attitude control is returned.
In other words, a process is performed to restore the executed roll control.

That is, air is exhausted from the supplied suspension unit, and air is supplied to the exhausted suspension unit, thereby returning the vehicle height to the state before roll control was performed. Thereafter, the process returns to step S1.

That is, in this embodiment, when the vehicle height is selected to be high, vehicle body posture control different from vehicle height adjustment is not performed.

Next, the operation of another embodiment of this invention will be explained. When the ignition key is turned on, the controller 36 executes the process shown in the flow chart shown in FIG. In step 11 of FIG. 3, it is determined whether or not it is necessary to prevent the vehicle from rolling, that is, to control the roll. This is to determine whether roll control is necessary, for example, when the lateral acceleration detected by the acceleration sensor 44 is equal to or greater than a predetermined value. If the determination in step S11 is ``YES'', the process advances to step S12, where it is determined whether the high vehicle height (HIGH) is selected by the vehicle height selection switch 45. If the determination in step S12 is "NO", the process proceeds to step S13, where roll control is performed to suppress changes in the attitude of the vehicle body. This is the right suspension unit S _FR ,
Main and auxiliary air spring chambers 11 and 12 of S _RR and left suspension unit S _FL , S _RL , one side unit
By supplying air to the main air spring chamber and exhausting air from the main and sub air spring chambers 11 and 12 of the unit on the other side, roll control is performed to suppress changes in the attitude of the vehicle body. Next, the process advances to step S14 to set the flag _F1 in the controller 36.
is set to "1". On the other hand, if the determination in step S12 is "YES", the process proceeds to step S15 and the vehicle speed is determined based on the signal from the vehicle speed sensor 41.
It is determined whether or not it is less than V ₂ Km/h. This step
If it is judged as “YES” in S15, the step
Proceeding to S16, it is determined whether the attitude control function is selected by the attitude control switch 46. If the determination in step S16 is "NO", the process advances to step S17 and the roll control is stopped. That is, the air supply solenoid valves 221 to 224 and the exhaust solenoid valves 271 to 274 are closed. Then, the process returns to step S11. By the way, if the determination in step S11 is "NO", the process advances to step S18, where it is determined whether or not the flag _F1 is set to "1". This step
If it is judged as “YES” in S18, the step
Proceed to S19 and attitude control is returned. In other words, a process is performed to restore the executed roll control.
In other words, the air is exhausted from the supplied suspension unit, and the attitude of the vehicle body is returned to the state before roll control is performed by supplying air to the exhausted suspension unit. Below are the steps
Return to processing in S11.

That is, according to the embodiment described above, when the vehicle speed is less than a predetermined value (V ₂ Km/h) and the vehicle height is selected to be high, vehicle body posture control different from vehicle height adjustment is not performed.

As detailed above, according to this invention, when a high vehicle height is selected, the vehicle body posture control is not automatically performed, so that the vehicle height can be selected to be high and drive on rough roads. Therefore, it is possible to provide an electronically controlled suspension device that can prevent vehicle body attitude control other than vehicle height adjustment from being performed in some cases.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an electronically controlled suspension device according to an embodiment of this invention, Fig. 2 is a flowchart showing the operation of the same embodiment, and Fig. 3 is a diagram showing the operation of another embodiment of this invention. It is a flowchart. 14... Actuator, 16... Air cleaner, 18... Dryer, 19... Compressor,
21... Reserve tank, 221-224... Air supply solenoid valve, 241, 242... Communication solenoid valve, 271-274... Exhaust solenoid valve, 36... Controller, 45
...Vehicle height selection switch.

Claims (1)

[Scope of utility model registration request] A vehicle height selection means for selecting a vehicle height, a running state detection means for detecting a running state of the vehicle, a suspension unit provided for each wheel and each having an air spring chamber, an air pressure source, and each of the above air spring chambers. control valve means for controlling the supply and discharge of air in each of the air spring chambers; and control valve means for controlling the operation of each of the control valve means based on the selected state of the vehicle height selection means to select a selected vehicle height. In addition to achieving this, when it is detected from the output of the running state detection means that a change in attitude of the vehicle body occurs, the operation of each of the control valve means is instantaneously controlled independently to suppress the change in attitude of the vehicle body. and a control means configured to stop the attitude change suppression control when a high vehicle height is selected by the vehicle height selection means. Suspension device.