JPH0326969Y2 - - 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 (lateral vibration) of a vehicle body.

[Technical background of the invention and its problems] 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. If the decision as to whether or not to start roll control was made based on the lateral acceleration acting on the vehicle body, the roll control would lag behind the actual vehicle body roll, making it difficult to accurately determine whether or not to start roll control. There is a problem that roll control is not possible. Furthermore, when determining whether or not to perform roll control based on the lateral acceleration acting on the vehicle body, when the vehicle is traveling straight on a rough road, the unevenness of the road surface causes the vehicle body to sway in the lateral direction. There is a problem in that the G sensor that outputs acceleration outputs data that requires roll control and roll control is started, causing discomfort to the occupant.

[Purpose of invention]

The present invention was developed 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 in the fluid spring chambers provided in each left and right suspension unit. In an electronically controlled suspension device equipped with
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 control time given by the vehicle speed-steering wheel angular velocity map is determined;
When the handle angular velocity detected by the handle angular velocity detection means is less than a predetermined value, the control time given by the G sensor map is determined based on the acceleration data output from the G sensor for a set time or more, and the fluid is supplied to the fluid spring chamber. An object of the present invention is to provide an electronically controlled suspension device capable of performing accurate roll control by controlling the opening and closing of an air supply control valve and an exhaust control valve for controlling exhaust to control the roll of a vehicle body.

[Summary of the idea]

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 left and right suspension unit, the steering wheel angular velocity is detected by the steering wheel angular velocity detection means. When the steering wheel angular velocity is above a predetermined value, the control time given by the vehicle speed-steering wheel angular velocity map is determined, and when the steering wheel angular velocity detected by the steering wheel angular velocity detecting means is less than a predetermined value, the acceleration is output from the G sensor for the set time. The control time given by the G sensor map is determined based on the data, and the air supply control valve and the exhaust control valve for controlling the supply and discharge of fluid to the fluid spring chamber are controlled to open and close, thereby controlling the roll of the vehicle body. When the steering wheel is turned rapidly, roll control is performed quickly, and when the steering wheel is turned slowly, roll control is performed based on acceleration data output from the G sensor for a set time or more.

[Example of idea]

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 to hard or soft,
In other words, the damping force switching valve 14a of the shock absorber 13 is rotationally controlled by the actuator 14,
It is selected whether the first damping chamber 13a and the second damping chamber 13b are communicated only through orifice _a1 or through both orifices _a1 and _a2 . 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 . The detection signal of 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 side and the other to the vehicle body side, and the distance from the normal vehicle height level and the low or high vehicle height level is detected respectively. 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 for detecting 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 execution of 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 whose operation signal 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 indicates 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 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 and steering wheel angular velocity is cleared to zero. Then, proceed to step S2, and the time when the valve was opened/closed is stored in the map memory.
Tm is cleared to 0. Next, proceeding to step S3, 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. This allows the air spring chambers 11 and 12 of the left and right suspension units to communicate with each other. And step
Proceed to S4, flow path selection solenoid valve 30,
It is confirmed that 32 is open. Here, if the valves 30 and 32 are closed, the control unit 36 opens the valves. As a result, the large diameter passage is selected for both the air supply route and the exhaust route. Next, the process proceeds to step S5, where the steering wheel angle output from the steering wheel angle sensor 42 and the vehicle speed data output from the vehicle speed sensor 41 are read into the control unit 36, and the steering wheel angular velocity, which is the temporal change in the steering wheel angle, is controlled. It is calculated in unit 36. Then, the process proceeds to step S6, where it is determined whether the steering wheel angle is within the neutral range. This step
If ``YES'' is determined in S6, 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, where the communication solenoid valves 241 and 242 are closed under the control of the control unit 36. This results in
Air spring chamber 1 of left and right suspension units
1 and 12 are disconnected. Next, the process proceeds to step S9, where it is determined whether the steering wheel angular velocity obtained in step S1 is greater than or equal to a threshold value. If the determination is ``YES'' in step S9, the process proceeds to step S10, and the control time Tp for controlling the valve opening is determined based on the vehicle speed-steering wheel angular velocity map shown in FIG.
is required. 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 left or right is stored. Then, in step S12, the control time T for actually controlling the valve is calculated. Here, T=Tp-Tm. Since Tm is set to 0 in the initial setting, T=Tp. Then, the process advances to step S13 and 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 step S14, the direction X and control time T are controlled by the control unit 36. 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 the 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 transferred to 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 S _FL ,
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, 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 decreases and the vehicle height on the left side increases, so air is supplied to the right suspension units S _FR and S _RR , and air is exhausted from the left suspension units S _FL and S _RL . .
That is, according to the control signal from the control unit 36, the right air supply solenoid valve 222,
224, left exhaust solenoid valve 271,
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 22.
Air is supplied to the right-hand suspension units S _FR and S _RR via 2,224. Simultaneously with this air supply operation, air is discharged from the main air spring chambers 11 of the left suspension units S _FL and S _RL through the left exhaust solenoid valves 271 and 273, the exhaust piping 28, and the exhaust flow path selection. It is released to the atmosphere via the valve 32, large-diameter exhaust pipe 33, check valve 29, 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 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. Thereafter, the process proceeds to step S15.

By the way, if the determination in step S9 is "NO" (that is, the steering wheel angular velocity is determined to be less than the threshold value), the process proceeds to step S16, where the acceleration data output from the G sensor 44 is sent to the control unit 36. is read into. The process then proceeds to step S17, where it is determined whether the acceleration data read in step S16 has been continuously output _{for t0} seconds. The length of t ₀ seconds is a set time that allows the output of the G sensor 44 to be ignored when driving on a rough road. If the determination in step S17 is ``YES'', the process advances to step S18. That is, as shown in FIG. 4A, if the acceleration data output from the G sensor 44 is continuously output for _t0 seconds or more, it is determined as "YES". Then, proceeding to step S18, the control unit 36 controls the flow path selection solenoid valves 30, 3.
2 is turned off and closed. As a result, the short route is selected as the air supply side and exhaust side routes. next,
Proceeding to step S19, the control time Tp for controlling the opening of the valve is determined from the G sensor map shown in FIG.
Thereafter, the processes of steps S11 to S15 described above are performed.
Here, the timing for opening the air supply solenoid valve and the exhaust solenoid valve in step S14 is shown in FIG. 4B.

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,
Control time required in step S10 or S19
Since Tp 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 determined in step S12, and the control for that control time T is commanded in step S14. .

[Effect of idea]

As detailed above, according to the present invention, an electronically controlled suspension system is 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. In the acceleration device, if the acceleration data output from the G sensor is continuously output for a set time or longer, it is considered valid, so the threshold value for instantaneous output due to unevenness of the road surface, etc. Since acceleration data exceeding the value can be ignored, it is possible to prevent the passenger from feeling uncomfortable due to roll control being erroneously started while driving straight on a rough road.

[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-handle angular velocity map, and Fig. 4 is a diagram showing an electronically controlled suspension device according to an embodiment of the present invention. Figures A to D are timing charts for explaining the operation, and Figure 5 is a diagram showing a G sensor map. 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)

[Scope of utility model registration request] 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, the fluid spring chambers of the suspension units are An air supply control valve installed in the air supply path that sends fluid to the suspension unit, an exhaust control valve installed in the exhaust path that discharges fluid from the fluid spring chamber of the suspension unit, and the handle angular velocity are detected. a steering wheel angular velocity detection means,
A G sensor that detects the lateral acceleration acting on the vehicle body, a vehicle speed-handle angular velocity map with a control time set approximately corresponding to the lateral acceleration used for the vehicle body determined by the vehicle speed and the steering wheel angular velocity, and the vehicle speed that acts on the vehicle body. It has a G sensor map in which a control time is set according to the acceleration in the lateral direction, 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 control time given by the vehicle speed-steering wheel angular velocity map is set. and when 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 G sensor map is determined based on the acceleration data output from the G sensor for a set time or more, and the control time is determined for the air supply. An electronically controlled suspension device comprising a control valve and a controller that controls the opening and closing of the exhaust control valve to control the roll of a vehicle body.