JPH0359847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an electronically controlled suspension device that prevents roll (rolling) of a vehicle body.

[Technical background of the invention and its problems]

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, it is determined whether or not roll control is to be performed. If this was done based only on the value of the horizontal acceleration acting on the vehicle body,
There is a problem in that the roll control lags behind the actual vehicle body roll. Therefore, if the value of the steering angular velocity of the steering wheel is also taken into account as a condition for whether or not to start roll control, it is possible to predict vehicle body roll and eliminate the above-mentioned problem. In this case, when roll control is started based on the steering wheel steering angular velocity, quick roll control is required because the roll generated in the vehicle body is sudden, whereas roll control is started based on lateral acceleration. When starting, the pandle steering angular velocity should be small and the roll that occurs in the vehicle body is slow, so a slower roll control is required than the quick roll control described above.

[Purpose of the invention]

The present invention has been made in view of the above points, and an object of the present invention is to select a large diameter passage using a passage selection valve 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 control time given by the angular velocity map is determined, and the supply control valve and the discharge control valve are controlled to open and close to control the roll of the vehicle body. The small diameter passage is selected by the road selection valve, and the control time given by the G sensor map is determined based on the acceleration data output from the G sensor, and the opening/closing control of the supply control valve and the discharge control valve is controlled to control the roll of the vehicle body. An object of the present invention is to provide an electronically controlled suspension device that can perform accurate roll control.

[Summary of the invention]

If the steering wheel angular velocity detected by the steering wheel angular velocity detection means is greater than or equal to a predetermined value, the flow path selection valve selects the large diameter passage, determines the control time given by the vehicle speed-steering wheel angular velocity map, and controls the supply control valve and discharge. Controls the roll of the vehicle body by controlling the opening and closing of the valve, and when the steering wheel angular velocity detected by the steering wheel angular velocity detection means is less than a predetermined value, the small diameter passage is selected by the flow path selection valve, based on the acceleration data output from the G sensor. The control time given by the G sensor map is determined to control the opening and closing of the supply control valve and discharge control valve to control the roll of the vehicle body. When the steering wheel is suddenly turned, roll control is quickly performed and the steering wheel is When the vehicle is steered slowly, roll control is performed slowly.

[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. 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 the suspension units S _RL to S _FL via the air supply piping 23 in which the air supply pipes 224 are interposed. In addition, the main and auxiliary air spring chambers 11 and 1 of the suspension units S _RL and S _RR
2 is 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 1 of the suspension units S _FL and S _FR are
2 are connected by a communication pipe 26 in which a communication solenoid valve 242 is interposed. In addition, the main and sub air spring chambers 11 and 12 of each of the suspension units S _RL to S _FL are equipped with an exhaust solenoid valve 271.
Exhaust pipe 28, check valve 29, dryer 18, solenoid valve 1 in which ~274 are installed
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 control unit 36. Further, 37 is connected to the communication pipe 25, and is connected to the main and sub air spring chambers 11, 37 of the rear wheel suspension units S _RR and S _RL .
This is a pressure switch that detects the internal pressure of 12. A detection signal from this pressure switch 37 is sent to the control unit 36. Further, 38F is a front vehicle height sensor attached to the lower arm 39 on the front right side of the vehicle 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 vehicle to detect the rear vehicle height. This is a rear vehicle height sensor that detects the vehicle height (rear vehicle height). Vehicle height detection signals output from the vehicle height sensors 38F and 38R are input to the control unit 36. The sensors 38F and 38R have Hall IC elements and magnets, one of which 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, respectively. In addition, 41 is a vehicle speed sensor that detects vehicle speed,
A detection signal output from the vehicle speed sensor 41 is input to the control unit 36. moreover,
A steering wheel steering angle sensor 42 detects the steering angle of the steering wheel 43, and this sensor 42 outputs a steering wheel steering angle detection signal to the control unit 36. Further, 44 is an acceleration G sensor as a vehicle body posture sensor that detects a change in the posture of the vehicle body.
It is designed to detect the speed of the horizontal rack.
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. 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
51 outputs an engine rotational speed signal to the control unit 36, and 51 is an ignition key switch whose operation signal is output to the control unit 36. 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. Further, 53 is a hardware selection switch for hardware setting the damping force of each suspension unit S _FL , S _FR , S _RL , S _RR .

In addition, the above-mentioned solenoid valves 17, 221 to 2
24, 271 to 274, 30, 32, 34 are normally closed 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. When the ignition switch is turned on, the process shown in the flowchart of FIG. 2 is performed. That is, in step S1, the data in the area provided in the control unit 36 for storing the vehicle speed, steering wheel angular velocity, steering wheel angle, and lateral G (lateral acceleration) is cleared to zero.
Then, the process proceeds to step S2, where the time Tm for controlling the opening and closing of the valve, which is stored in the map memory, is cleared to zero. Next, the process proceeds to step S3, where it is confirmed that the communication solenoid valves 241 and 242 are open. Here, if the communication solenoid valves 241 and 242 are closed, the valves are turned off and opened under the control of the control unit 36. As a result, the air spring chambers 11, 1 of the left and right suspension units
2 are communicated. The process then proceeds to step S4, where it is confirmed that the flow path selection solenoid valves 30 and 32 are open. Here, the above valve 3
If the valves 0 and 32 are closed, the valve is opened under the control of the control unit 36. As a result, the large diameter passage is selected for both the air supply route and the exhaust route. Next, proceeding to step S5, the steering wheel angle output from the steering wheel angle sensor 42, the vehicle speed data output from the vehicle speed sensor 41, and the G
The lateral G output from the sensor 44 is read into the control unit 36, and the control unit 36 calculates the steering wheel angular velocity, which is the temporal change in the steering wheel angle. And step S
Proceeding to step 6, it is determined whether the steering wheel angle is within the neutral range. "YES" in this step S6
If it is determined that this is the case, the process returns to step S2.
On the other hand, if the determination in step S6 is "NO", the process proceeds to step S7, where it is determined whether or not the steering direction of the steering wheel is on the return side. If the determination in step S7 is ``YES'', the process advances to step S8. That is, if the steering wheel is out of the neutral range and the steering direction is not the return direction, the process proceeds to step S8, and the communication solenoid valves 241 and 2 are controlled by the control unit 36.
42 is closed. As a result, the air spring chambers 11 and 12 of the left and right suspension units are disconnected from each other. Next, the process proceeds to step S9, where it is determined whether the steering wheel angular velocity determined in step S1 is greater than or equal to a threshold value. If the determination in step S9 is ``YES'', the process proceeds to step S10, where the control time Tp for controlling the valve opening is determined from the vehicle speed-steering wheel angular velocity map shown in FIG.
This Tp becomes the value of t1 to t3. Then, the process proceeds to step S11, where the required direction X, that is, whether the steering wheel is being steered in the left or right direction is stored. Then, in step S12, a control time T for actually controlling the opening of the valve is calculated.
Here, T=Tp-Tm. Since Tm is set to 0 in the initial setting, T=Tp.
Then, the process proceeds to step S13, where the control time T is determined. In this step S13, “T≦
0'', the process returns to step S5. In other words, the valve is not opened. On the other hand, if it is determined in step S13 that "T>0", the process advances to step S14. In this step S14, the control unit 36
The direction X and control time T are controlled by.
For example, a case where the steering wheel is being steered to the right will be described. In this case, the vehicle height on the left side decreases and the vehicle height on the right side increases, so air is supplied to the left suspension units S _FL and S _RL , and air is exhausted from the right suspension units S _FR and S _RR . . In other words, the left air supply solenoid valves 221 and 22 are controlled by a control signal from the control unit 36.
3. Right side exhaust solenoid valve 272, 27
4. It is turned on for a control time T. As a result, the compressed air sent from the reserve tank 21 is routed through the air supply flow path selection valve 30, the large-diameter air supply pipe 31, and the air supply pipe 2.
3. Left air supply solenoid valve 221, 22
3 through the left suspension unit _TFL ,
Air is supplied to S _RL . Also, at the same time as this air supply operation,
The air exhausted from the main air spring chamber 11 of the right suspension units S _FR and S _RR is routed through the right exhaust solenoid valves 272 and 274 and the exhaust piping 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 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 S15 and the map memory is updated. In other words, Tp is set to Tm. and,
Return to step S5 above. Here, the handle 43
When the vehicle is returned to neutral, the determination in step S6 is ``YES'' and the process proceeds to step S3, where the communication solenoid valves 241 and 242 are opened and attitude control is canceled.

On the other hand, a case where the steering wheel 43 is steered to the left will be described. In this case, the vehicle height on the right side is lowered and the vehicle height on the left side is higher, so air is supplied to the right suspension units S _FR and S _RR and exhausted to the left suspension units S _FL and S _RL . Ru. In other words, the control signal from the control unit 36 causes the right air supply solenoid valve 22 to
2,224, left exhaust solenoid valve 27
1,273 is turned on for a control time T. As a result, the compressed air sent from the reserve tank 21 is routed through 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 2.
Air is supplied to the right suspension units S _FR and S _RR via 22 and 224 . At the same time as this air supply operation, the left suspension units S _FL and S _RL
The air discharged from the main air spring chamber 11 of , and is released to the atmosphere through an 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 air supply solenoid valves 222, 224,
The left exhaust solenoid valves 271 and 273 are closed and maintained in that state. Thereafter, the process proceeds to step S15.

By the way, if "NO" is selected in step S9 above,
If it is determined that the flow path selection solenoid valves 30 and 32 are closed, the flow path selection solenoid valves 30 and 32 are turned off and closed by the control unit 36 at step S16. As a result, the short route is selected as the air supply side and exhaust side routes. Next, proceed to step S17 and proceed to G in FIG.
Control time to control valve opening from sensor map
Tp is required. Hereinafter, the above steps S11~
The process of S15 is performed.

Furthermore, if the vehicle speed-steering wheel angular velocity map or G sensor map changes to a region with a larger control time while the vehicle is turning,
Since the control time Tp found in step S10 or S17 is larger than the control time Tm already stored in the map memory, the control time T (=Tp - Tm) that needs to be added is found in step S12, and then added in step S14. Control for control time T is commanded.

Furthermore, in the above embodiment, the left roll when steering to the right and the right roll when steering to the left were explained.
In addition, attitude control during braking (nose dive) and acceleration (microwave) can be performed by opening and closing valves as shown in FIG.

〔Effect of the invention〕

As described in detail above, according to the present invention, when the steering wheel angular velocity detected by the steering wheel angular velocity detecting means is greater than or equal to a predetermined value, the flow path selection valve selects the large diameter passage, and control is provided by the vehicle speed-steering wheel angular velocity map. Controls the roll of the vehicle body by controlling the opening and closing of the supply control valve and discharge control valve based on the time,
When the handle angular velocity detected by the handle angular velocity detection means is less than a predetermined value, the flow path selection valve selects a small diameter passage, and based on the acceleration data output from the G sensor, the control time given by the G sensor map is determined and used for supply. Since the control valve and the discharge control valve are controlled to open and close, roll control can be performed quickly when the handle is turned suddenly, and slowly when the handle is turned slowly, allowing accurate roll control. An electronically controlled suspension device capable of performing roll control can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an electronically controlled suspension device according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the same embodiment, FIG. 3 is a diagram showing a vehicle speed-steering wheel angular velocity map, and FIG. The figure shows a G sensor map, and FIG. 5 shows valve opening and closing. 11... Main air spring chamber, 12... Sub-air spring chamber, 14... Actuator, 21... Reserve tank, 221-224... Air supply solenoid valve, 241, 242... Communication solenoid valve, 271, 274...Exhaust solenoid valve, 36...Control unit.

Claims (1)

[Claims] 1. In an electronically controlled suspension system 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 of the left and right suspension units, A supply control valve installed in each supply path for feeding fluid into the spring chamber, and a discharge control valve installed in each discharge path for draining fluid from the fluid spring chamber of each suspension unit. , a flow path selection valve that is interposed in the supply path and the discharge path and selects the large diameter path or the small diameter path, a steering wheel angular speed detection means that detects the steering wheel angular speed, and a G sensor that detects the acceleration acting in the lateral direction of the vehicle body. A sensor, a vehicle speed-steering wheel angular velocity map in which a 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 a control time is set in accordance with the lateral acceleration acting on the vehicle body. 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 large diameter passage is selected by the passage selection valve, and the control time given by the vehicle speed-steering wheel angular velocity map is controlled. and controlling the roll of the vehicle body by controlling the supply control valve corresponding to the fluid spring chamber on the contraction side and the discharge control valve corresponding to the fluid spring chamber on the expansion side to open for the same control time; When the handle angular velocity detected by the handle angular velocity detection means is less than a predetermined value, the flow path selection valve selects a small diameter passage, and the control time given by the G sensor map is determined based on the acceleration data output from the G sensor. and a controller that controls the opening of the supply control valve corresponding to the fluid spring chamber on the contraction side and the discharge control valve corresponding to the fluid spring chamber on the expansion side for the same control time to control the roll of the vehicle body. An electronically controlled suspension device comprising: