JPH0359845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronically controlled suspension device for preventing roll of an automobile.

[Technical background of the invention and its problems] A suspension control device equipped with an attitude control function that reduces roll displacement of a vehicle body by individually adjusting the fluid pressure of fluid spring chambers provided in each left and right suspension unit. However, if the decision as to whether or not to perform roll control was made based on the left and right height displacement of the vehicle body, the drawback was that the roll control would lag behind the actual vehicle body roll. be.

[Purpose of the invention]

The present invention has been made in view of the above points, and its purpose is to provide an attitude control function that reduces roll displacement of the vehicle body by individually adjusting the fluid pressure of the fluid spring chambers provided in each of the left and right suspension units. An object of the present invention is to provide an electronically controlled suspension device that can accurately perform roll control without delay.

[Summary of the invention]

In a suspension control device equipped with an attitude control function that reduces roll displacement of the vehicle body by individually adjusting the fluid pressure in the fluid spring chambers provided in each left and right suspension unit, the judgment to start roll control is made based on the steering wheel angular velocity. When the steering wheel angular velocity is above a predetermined value, the control time is determined using a vehicle speed-steering wheel angular velocity map, and when the steering wheel angular velocity is less than a predetermined value, the control time is determined using a vehicle height sensor map.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An electronically controlled suspension device according to an embodiment of the present invention will be described below 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 to hard or soft,
In other words, the actuator 14 controls the rotation of the damping force switching valve 14a of the shock absorber 13, and the first damping chamber 13a and the second damping chamber 13b are
It is selected whether the communication is through only orifice a ₁ or through both orifices a ₁ and a ₂ . And 15 is a bellows. The actuator 14 controls communication and non-communication between the main air spring chamber 11 and the auxiliary air spring chamber 12, and switches the air spring reaction force 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 control unit 36, which will be described later. The reserve tank 21 is equipped with an air supply solenoid valve 221.
224 are connected to the main and auxiliary air spring chambers 11 and 12 of each suspension unit S _RL to S _FL via the air supply piping 23 in which air supply pipes 224 are installed. In addition, the main and sub air spring chambers 1 of the suspension units S _RL and S _RR
1 and 12 are connected by a communication pipe 25 in which a communication solenoid valve 241 is installed, and the main and sub air spring chambers 1 of the suspension units S _FL and S _FR are
1 and 12 are connected by a communication pipe 26 in which a communication solenoid valve 242 is interposed. Also,
The main and auxiliary air spring chambers 11 and 12 of each of the above-mentioned suspension units S _RL to S _FL include an exhaust pipe 28 in which exhaust solenoid valves 271 to 274 are installed, a check valve 29, a dryer 18, a solenoid valve 17, and an air cleaner. 16 to the atmosphere. 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 . Further, a hard/soft switching solenoid valve 34 is interposed between the air supply pipe 23 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 control unit 36. Also, 3
A pressure switch 7 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 rear wheel suspension units S _RR and S _RL . A detection signal from this pressure switch 37 is sent to the control unit 36. Also, 38F
38R is a front vehicle height sensor attached to the lower arm 39 on the front right side of the automobile to detect the front vehicle height (front vehicle height), and 38R is attached to the lateral rod 40 on the rear left side of the automobile to detect the rear vehicle height (rear vehicle height). This is a rear vehicle height sensor that detects vehicle height.
Vehicle height detection signals output from the vehicle height sensors 38F and 38R are input to the control unit 36. The above sensors 38F and 38R are Hall
One of the IC elements and magnets is attached to the wheel and the other to the vehicle body 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 control unit 36. Furthermore, 42 is a steering wheel steering angle sensor that detects the steering angle of the steering wheel 43, and this sensor 42 sends a steering wheel steering angle detection signal to the control unit 3.
It is output to 6. Further, reference numeral 44 denotes an acceleration (G) sensor as a vehicle body posture sensor that detects changes in the posture of the vehicle body, and this acceleration sensor 44 is adapted to detect changes in the vehicle body posture such as pitch, roll, and yaw on the automobile spring. . For example, when there is no acceleration, the weight is in a hanging state,
Since the light from the light emitting diode is blocked by the shielding plate and does not reach the photodiode, it is detected that there is no acceleration. Then, when acceleration acts in the front and back, left and right, or up and down directions, 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), and vehicle height adjustment (AUTO);
Reference numeral 46 denotes an attitude control selection switch for selecting attitude control to prevent the vehicle from rolling.
Signals from the switches 45 and 46 are input to the control unit 36. Further, numeral 47 is an oil pressure indicator that indicates whether the oil pressure of the engine oil has reached a predetermined value and the amount of oil pressure, and the display operation of this oil pressure indicator 47 is controlled by the control unit 36. A brake switch 48 detects the depression and amount of depression of the brake, and its detection signal is input to the control unit 36. Further, reference numeral 49 denotes an accelerator opening sensor for detecting the opening of the accelerator, and an accelerator opening signal outputted from this sensor 49 is input to the control unit 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 control unit 36. Furthermore, 51 is an ignition key switch, the operation signal of which is sent to the control unit 3 mentioned above.
6 is output. A gear position sensor 52 detects the gear position (shift position), and this sensor 52 outputs a gear position signal to the control unit 36. In addition, 53 is each suspension unit S _FL ,
This is a hardware selection switch for setting the damping force of S _FR , S _RL , and S _RR .

In addition, the above-mentioned solenoid valves 17, 221 to 2
24, 271 to 274, 30, 32, 34 are normally open valves, the solenoid valves 241 and 24
2 is a normally open valve.

Next, the operation of an embodiment of the present invention configured as described above will be explained. The processing in the flowchart of FIG. 2 is carried out by the control unit 36. When the ignition key is turned on, first, as shown in step S1, the vehicle speed data and steering wheel angular velocity data stored in the control unit 36 are set to zero. and,
Proceeding to step S2, the valve control time Tm in the map memory is set to zero. Next, step
At S3, it is confirmed that the communication solenoid valves 241 and 242 are open. and,
Proceed to step S4 and check the steering wheel angle sensor 42.
The steering wheel angle (steering angle) detected by the steering wheel, the steering wheel angular velocity which is a temporal change in the steering wheel angle, and the vehicle speed detected by the vehicle speed sensor 41 are read into the control unit 36. Then, the process proceeds to step S5, where it is determined whether the above-mentioned steering wheel angle is within the neutral range. This step S5
If it is determined as “YES”, the above steps will be executed.
Return to S2. On the other hand, if the determination in step S5 is "NO", the process proceeds to step S6. In this step S6, the communication solenoid valve 24
1 and 242 are closed. This allows the main and sub air spring chambers 1 of the left and right suspension units to
1 and 12 are cut off. Next, step
In step S7, the steering direction of the steering wheel detected by the steering wheel angle sensor 42 is read into the control unit 36, and in step S8 it is determined whether the steering direction is clockwise (rightward). If the determination in step S8 is ``YES'', the process proceeds to step S9, where it is determined whether the position of the handle 43 is to the right of the neutral position. This step
If it is determined in S9 as "NO", that is, the steering wheel is being steered to the right and the steering wheel position is on the left side (this is a state in which the steering wheel is turned to the left and returned to the right), the process proceeds to step S10. Communication solenoid valves 241 and 242 are opened.
This is because roll control is not performed when the handle is turned to the return side, so the communication solenoid valves 241 and 242 are opened. On the other hand, if the determination in step S9 is ``YES'', the process proceeds to step S11, where it is determined whether the steering wheel angular velocity read in step S4 is equal to or greater than a threshold value. If the determination is ``YES'' in step _S11 , the process proceeds to step S12, where the control time Tp is determined from the continuous speed-steering wheel angular velocity map shown in FIG. Proceeding to S13, the control time Tp is determined from the vehicle height sensor map shown in FIG. here,
Each map is set so that the control time Tp becomes longer as the steering wheel angular velocity increases. next,
Proceed to step S14 and calculate the control time T (=Tp−Tm)
is calculated. Here, since Tm=0 is initially set, T=Tp. Next, step S15
Then, it is determined whether "T>0" and "T≦0". Since "T=Tp>0", the process advances to step S16 and the control unit 36 issues a command to control the control time T. That is, the left air supply solenoid valves 221, 223 and the right exhaust solenoid valves 272, 274 are turned on for a control period T by a control signal from the control unit 36. As a result, the compressed air sent from the reserve tank 21 is transferred to the air supply flow path selection valve 30,
Air is supplied to the left suspension units S _FL and S _RL via the large-diameter air supply pipe 31, the air supply pipe 23, and the left air supply solenoid valves 221, 223. Simultaneously with this air supply operation, the air discharged from the main air spring chambers 11 of the right suspension units S _FR and S _RR is passed through the right exhaust solenoid valve 27.
2,274, exhaust pipe 28, exhaust flow path selection valve 32, large diameter exhaust pipe 333 check valve 29,
It is released to the atmosphere via the dryer 18, valve 17, and air cleaner 16. In this way, the vehicle body can be kept horizontal when the steering wheel 43 is steered to the right. After the valves are opened for the control time T, the left air supply solenoid valves 221, 223 and the right exhaust solenoid valves 272, 274 are closed and maintained in that state. Then, the process advances to step S17 and the map memory is updated. In other words, Tm=Tp is set and the process returns to step S4. And the handle 43
returns to neutral, “YES” is selected in step S5.
When it is determined that this is the case, the communication solenoid valves 241 and 242 are opened in step S3, the internal pressures of the main air spring chambers 11 of the left and right suspension units are brought to the same pressure, and the attitude control is canceled.

On the other hand, if it is determined to be "ON" in step S8, the process proceeds to step S18, where it is determined whether the position of the handlebar 43 is to the right of the neutral position. If it is determined in this step S18 as "YES", that is, the steering wheel is being steered left and right and the steering wheel position is on the right side (this is a state in which the steering wheel is turned to the right and then returned to the left), the process proceeds to step S10. Then, the communication solenoid valves 241 and 242 are opened. This is because roll control is not performed when the handle is turned to the return side, so the communication solenoid valves 241 and 242 are opened.
On the other hand, if the determination in step S18 is "NO", the process proceeds to step S19, where it is determined whether each steering wheel speed read in step S4 is equal to or higher than a threshold value. If the determination is ``YES'' in step S19, the process proceeds to step S20, where the control time Tp is determined from the continuous speed-handle speed map shown in FIG. 3, and if the determination is ``NO'' in step S19, Proceed to step S21 and proceed to step S21.
The control time Tp is determined from the vehicle height sensor map shown in the figure. Here, each map is set so that the control time Tp becomes longer as the steering wheel angular velocity is greater. Next, the process proceeds to step S22, where the control time T (=Tp - Tm) is calculated. Here, Tm=
Since 0 is initially set, T=Tp.
Next, proceed to step S23 where "T>0" and "T≦"
Since it is determined that "T=Tp>0", the process advances to step S24, where the control unit 36 issues a command to control the control time T. In other words, the control signal from the control unit 36 causes the right air supply solenoid valves 222, 22 to
4. Left exhaust solenoid valve 271, 27
3 is turned on for a control time T. As a result, the compressed air sent from the reserve tank 21 is transferred to the air supply flow path selection valve 30, the large-diameter air supply pipe 31, the air supply pipe 23, and the right air supply solenoid valve 222, 2.
Right suspension unit S _FR via 24,
Air is supplied to S _RR . Also, at the same time as this air supply operation,
The air exhausted from the main air spring chamber 11 of the left suspension units S _FL and S _RL is routed through the left exhaust solenoid valves 271 and 273 and the exhaust pipe 2.
8, exhaust flow path selection valve 32, large diameter exhaust pipe 33,
Check valve 29, dryer 18, valve 1
7. It is released to the atmosphere via the air cleaner 16. In this way, the vehicle body can be kept horizontal when the steering wheel 43 is steered to the left. After the valves are opened for the control time T, the right side air supply solenoid valves 222, 224 and the left side exhaust solenoid valves 271, 273 are closed and maintained in that state.

Then, the process advances to step S25 and the map memory is updated. In other words, Tm=Tp is set and the process returns to step S4. When the handle 43 returns to the neutral position, the determination is ``YES'' in step S5, and the communication solenoid valves 241 and 242 are opened in step S3, so that the internal pressures of the main air spring chambers 11 of the left and right suspension units are the same. and attitude control is released.

Furthermore, if the driving condition changes to a region where the control time is larger than the vehicle speed-steering wheel angular velocity map or vehicle height sensor map while turning,
Since the control time Tp obtained in steps S12, S13, S20, and S21 is larger than the control time Tm already stored in the map memory, the additional control time T (= Tp
-Tm) is determined, and control of the control time T is commanded in step S16 or S24.

〔Effect of the invention〕

As detailed above, according to the present invention, suspension control is provided with an attitude control function that reduces roll displacement of the vehicle body by individually adjusting the fluid pressure of the fluid spring chambers provided in each of the left and right suspension units. In the device, when the steering wheel is turned suddenly, the vehicle speed - steering wheel angular velocity map is used to calculate the valve control time, and when the steering wheel is turned slowly, the vehicle height sensor map is used to calculate the valve control time.
It is possible to provide an electronically controlled suspension device that can accurately control roll even when the steering wheel is turned suddenly or slowly.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an electronically controlled suspension device according to the present invention, Fig. 2 is a flowchart showing the operation of one embodiment, Fig. 3 is a diagram showing a vehicle speed-steering wheel angular velocity map, and Fig. 4 is a diagram showing the vehicle height. FIG. 3 is a diagram showing a sensor map. 11... Main air spring chamber, 221-224... Air supply solenoid valve, 241, 242... Communication solenoid valve, 271-274... Exhaust solenoid valve, 36... Control unit, 38F, 38R... Vehicle height sensor, 44...G
sensor.

Claims (1)

[Claims] 1. In an electronically controlled suspension device equipped with an attitude control function that reduces roll displacement of a single unit by individually adjusting the fluid pressure in the fluid spring chambers provided in each of the left and right suspension units, each fluid of the suspension unit is A supply control valve installed in each air supply path for feeding fluid into the spring chambers, and a discharge control valve installed in each discharge path for discharging fluid from each fluid spring chamber of the suspension unit. , the steering wheel angular velocity is detected by the steering wheel angular velocity detection means, the vehicle speed-steering wheel angular velocity map in which the control time is set approximately according to the lateral acceleration acting on the vehicle body determined by the vehicle speed and the steering wheel angular velocity, and the left and right vehicle height displacement of the vehicle body. It has a vehicle height sensor map in which a control time is set approximately according to the required lateral acceleration acting on the vehicle body, and when the steering wheel angular velocity detected by the steering wheel angular velocity detecting means is equal to or higher than a predetermined value, the vehicle speed minus the steering wheel is set. The control time given by the angular velocity map is determined, and if the steering wheel angular velocity detected by the steering wheel angular velocity detection means is less than a predetermined value, the control time given by the vehicle height sensor map is determined, and the control time given by the vehicle height sensor map is determined, and the control time given by the vehicle height sensor map is determined. An electronically controlled suspension comprising: a controller that controls the roll of the vehicle body by controlling the opening of the supply control valve corresponding to the fluid spring chamber and the discharge control valve for the fluid spring chamber on the extension side. Device.