JPH0242482Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] This invention solves the problem of the sinking of the right side of the car body (right roll) and the sinking of the left side of the car body ( This invention relates to an electronically controlled suspension device that controls left roll.

[Technical background of the invention and its problems]

Generally, when leftward acceleration is applied to the vehicle body when the vehicle turns left or right, a right roll phenomenon occurs in which the height of the right side of the vehicle body decreases and the left side of the vehicle rises.
On the contrary, when rightward acceleration is applied to the vehicle body when the vehicle turns right or right, a left roll phenomenon occurs in which the left side of the vehicle sinks and the height of the right side rises. Therefore, an electronically controlled suspension device that electronically suppresses such right roll phenomenon and left roll phenomenon has been considered. In other words, when this electronically controlled suspension device predicts that a change in attitude will occur in the vehicle body due to the left-right acceleration applied to the vehicle body or the time derivative of that acceleration, the system controls the spring reaction of the suspension unit in the direction in which the vehicle body sinks. This increases the force and reduces the spring reaction force of the suspension unit in the direction of floating, absorbing the above change in attitude and keeping the vehicle level. Here, the amount of increase and amount of decrease of the spring reaction force are set in advance as predetermined control amounts.

Thereafter, when the factor (for example, acceleration) that causes the attitude change as described above is reduced, the spring reaction force is controlled by a predetermined amount in the opposite direction to that described above, and the attitude control state is released.

However, in such an electronically controlled suspension device that always raises and lowers the suspension spring reaction force by a predetermined control amount, if the predetermined control amount is set in accordance with the posture control performed during normal leftward movement and rightward movement, for example, A problem arises in that large posture changes that occur when making a sharp left turn or a sudden right turn cannot be adequately controlled.

In addition, the amount of change in the posture of the vehicle when turning left or right is
It varies greatly depending on the number of passengers and cargo, so
If attitude control is always performed by only a predetermined amount of control as described above, for example, when there is only one occupant and the inertia of the vehicle body is small, the amount of attitude change will be relatively small.
There is a risk that posture control will be performed more than necessary. On the other hand, if there are five occupants and the inertia of the vehicle body is very large, on the other hand, the amount of attitude change will be quite large, so there is a risk that attitude control will not be performed effectively.

[Purpose of invention]

This idea was created in view of the problems mentioned above. For example, even when the inertia of the vehicle body changes due to the increase or decrease in the number of passengers, the amount of change in attitude varies greatly.
An object of the present invention is to provide an electronically controlled suspension device that can always perform posture control with an appropriate control amount.

[Summary of the idea]

In a suspension device that includes a spring member interposed between a wheel and a vehicle body, and a spring force adjustment device that adjusts the spring force of this spring member, a G output voltage that corresponds to the acceleration of the vehicle body in the left and right direction is used. When the sensor output voltage V+α/time differential value V' exceeds a threshold value, the spring force adjusting device is driven so that the spring member acts in a direction that opposes the left-right posture control of the vehicle body, maintains the driving of the spring force adjustment device when an average vehicle height obtained by averaging vehicle heights for each unit time outputted from a vehicle height sensor that detects the vehicle height for each predetermined time period falls within a first target range; In the electronically controlled suspension device, when the average vehicle height enters a second target range narrower than the first target range, the spring force adjustment device performs return control.

[Example of idea]

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, the air suspension unit
Since LS1, LS2, RS1, and RS2 each have almost the same structure, the air suspension unit will be referred to with the symbol S below, unless the left-wheel and right-wheel units are specifically explained. explain,
Only the parts necessary for vehicle height control will be illustrated and explained.

That is, the air suspension unit S incorporates a shock absorber 1, and this shock absorber 1 includes a cylinder attached to the front wheel or the rear wheel side, and a piston slidably inserted into the cylinder. Since the cylinder moves up and down relative to the piston rod 2 in accordance with the up and down movement of the wheel, shock can be effectively absorbed and the damping force changes in accordance with the stroke of the wheel.

By the way, a main air spring chamber 3 which also serves as a vehicle height adjustment fluid chamber is arranged coaxially with the piston rod 2 at the upper part of the shock absorber 1, and a part of this main air spring chamber is formed by a bellows 4. Therefore, the passage 2 provided in the piston rod 2
By supplying and discharging air to and from the main air spring chamber 3 via a, the piston rod 2 can be moved up and down.

Further, the outer wall of the shock absorber 1 is provided with a spring receiver 5a facing upward, and the outer wall of the main air spring chamber 3 is provided with a spring receiver 5a facing downward.
b is formed, and these spring receivers 5a, 5b
A coil spring 6 is loaded between them.

Thus, 11 is a compressor. This compressor 11 compresses the atmospheric air sent from the air cleaner 12 and supplies it to the dryer 13 . The compressed air dried with silica gel or the like from the dryer 13 is transferred to the reserve tank 15 via the check valve 14 . It is stored in the high pressure side reserve tank 15a. This reserve tank 1
5 is provided with a low pressure side reserve tank 15b. A compressor 16 driven by a compressor relay 17 is provided between the reserve tanks 15a and 15b. Further, a pressure switch 18 is provided which is turned on when the pressure in the low pressure side reserve tank 15b becomes equal to or higher than atmospheric pressure.
When the pressure switch 18 is turned on, the compressor relay 17 is driven. As a result, the reserve tank 15b is always kept below atmospheric pressure. The route by which compressed air is supplied from the high-pressure side reserve tank 15a to the suspension unit S is indicated by a solid arrow. That is, the compressed air from the reserve tank 15a is supplied to the air supply solenoid valve 19, the air supply flow rate control valve 20 consisting of a three-way valve (described later), the check valve 21, the front right solenoid valve 22, and the front left solenoid valve 23. The signal is then sent to the front right suspension unit RS1 and the front left suspension unit LS1. Similarly, the compressed air from the reserve tank 15a is supplied to an air supply solenoid valve 19, an air supply flow rate control valve 20 consisting of a three-way valve, which will be described later.
It is sent to the rear right suspension unit RS2 and the rear left suspension unit LS2 via the check valve 24, the rear right solenoid valve 25, and the rear left solenoid valve 26. On the other hand, the exhaust route from the suspension unit S is indicated by a broken line arrow. In other words, the exhaust from suspension units LS1 and RS1 is controlled by solenoid valves 22 and 23, and exhaust flow control valve 2.
7, is sent to the low pressure side reserve tank 15b via the exhaust direction switching valve 28 and residual pressure valve 29. In addition, suspension units LS1, RS
Exhaust from 1 is through solenoid valves 22, 23, exhaust flow control valve 27, and exhaust direction switching valve 2.
8, dryer 13, exhaust solenoid valve 30,
It is released to the atmosphere via the air cleaner 12. Furthermore, the exhaust from the suspension units LS2 and RS2 is routed through the solenoid valves 25 and 26, the exhaust flow rate control valve 27, the exhaust direction switching valve 28, and the residual pressure valve 29 to the low pressure side reserve tank 15b.
sent to. Note that when the pressure in the reserve tank 15b is lower than the pressure in the main air spring chamber 3, the residual pressure valve 29 becomes open, and the reserve tank 15b
When the pressure in the main air spring chamber 3 is greater than the pressure in the main air spring chamber 3, the residual pressure valve 29 is closed. Furthermore, the exhaust from the suspension units LS2 and RS2 includes solenoid valves 25 and 26, an exhaust flow control valve 27,
It is released to the atmosphere via the exhaust direction switching valve 28, the dryer 13, the exhaust solenoid valve 30, and the air cleaner 12.

Further, 31 is a vehicle height sensor, and this vehicle height sensor 3
1 is a right wheel height sensor 31R that is attached to the lower arm 32 of the front right suspension of the automobile and detects the right side vehicle height of the automobile, and a right wheel side vehicle height sensor 31R that is attached to the rear rod 33 of the rear left suspension of the automobile and detects the vehicle height of the right side of the automobile. The left wheel side vehicle height sensor 31L detects the vehicle height, and detection signals are supplied from these vehicle height sensors 31L and 31R to a control unit 34 serving as a vehicle height adjustment control section.

Each sensor 31L, 31 in the vehicle height sensor 31
R is designed to detect the distance from the normal vehicle height level, the low vehicle height level, or the high vehicle height level, respectively.

Furthermore, the speedometer has a built-in vehicle speed sensor 35, which detects the vehicle speed and transmits the detection signal to the control unit 3.
4.

Further, an acceleration sensor 36 is provided as a vehicle body posture sensor that detects changes in the posture of the vehicle body.
This acceleration sensor 36 is designed to detect changes in the vehicle body posture such as pitch, roll, and yaw on the automobile spring.
6, a differential transformer type is used to obtain a sensor output voltage V _G proportional to the magnitude of acceleration G acting on the vehicle body. This acceleration detection voltage
V _G is always supplied to the control unit 34.

Further, numeral 37 is an indicator for displaying oil pressure, and the display of this indicator 37 is controlled by the control unit 34. A steering sensor 38 detects the rotational speed of the steering wheel 39, that is, the steering speed, and its detection signal is sent to the control unit 34. Furthermore, 4
0 is an accelerator opening sensor (not shown) that detects the depression angle of an accelerator pedal of the engine, and its detection signal is sent to the control unit 34. Further, 41 is a compressor relay for driving the compressor 11, and this compressor relay 41 is controlled by a control signal from the control unit 34. Furthermore, 42 is a pressure switch that is turned on when the pressure in the reserve tank 15a is below a predetermined value, and its output signal is output to the control unit 34. That is, when the pressure in the reserve tank 15a falls below a predetermined level, the pressure switch 34 is turned on, and the compressor relay 41 is driven under the control of the control unit 34. As a result, compressor 1
1 is driven, compressed air is sent into the reserve tank 15a, and the pressure inside the reserve tank 15a is increased to a predetermined value or higher. Further, numeral 43 is a gear position sensor that detects a shift position of a transmission (not shown), and its detection signal is supplied to the control unit 34. Note that the solenoid valve 19,
22, 23, 25, 26, 30 and valve 20,
Opening/closing control of 27 and 28 is performed by control signals from the control unit 34. The solenoid valves 22, 23, 25, 26 and the valves 20, 27, 28 are three-way valves, and their two states are shown in FIG. FIG. 2A shows a state in which the three-way valve is driven, and in this state compressed air moves along the path indicated by arrow A. On the other hand, FIG. 2B shows a state in which the three-way valve is not driven, and in this state compressed air moves along the path indicated by arrow B. The solenoid valves 19 and 30 are two-way valves, and their two states are shown in FIG. FIG. 3A shows a state in which the solenoid valve is driven, and in this state compressed air moves in the direction of arrow C. On the other hand, when the solenoid valve is not driven, the situation is as shown in FIG. 3B, and in this case, there is no flow of compressed air.

Next, the operation of an embodiment of the present invention constructed as described above will be explained with reference to the flowchart shown in FIG. The control shown in the flowchart of FIG. 4 is performed by the control unit 34. First, the output voltage V corresponding to the acceleration in the left-right direction of the vehicle body output from the G sensor 36 and the time differential value V' of the output voltage are Control unit 34
(step S1). And V+
αV' (hereinafter referred to as ΣV) is calculated (step S2). Furthermore, the vehicle height detection signal output from the vehicle height sensor 31 is read into the control unit 34, for example, every 6 mS (step S3). Then, t1 of the vehicle height detection signal read every 6 seconds
The average vehicle height for a second (for example, one second) is calculated (step S4). Then, the process proceeds to step S5, where it is determined whether or not the attitude control solenoid valve is in a holding operation. Here, "during holding operation" means that air supply solenoid valve 1 is being operated during attitude control.
9. Either the exhaust solenoid valve 30 and the right wheel solenoid valves 22, 25 or the left wheel solenoid valves 23, 26 are in the OFF state, and the exhaust direction switching valve 28 is in the ON operation, and the right wheel suspension is Unit RS1, RS2
This refers to a state in which the main air spring chambers 3 of the left-wheel suspension units LS1 and LS2 are kept closed independently. If the determination in step S5 is "NO", the process advances to step S6. Then, the above ΣV and the threshold value B are compared (step S6). In this step S6, if it is determined that "ΣV≧B", the process advances to step S7. And this step S
In step 7, it is determined whether "B≦ΣV<C".
Here, C is a threshold value made of a constant larger than the above threshold value B. If "B≦ΣV<C", the control valves 20, 27 are turned on and the small diameter passage is selected as the air supply/exhaust path (step S8). In other words, supply and discharge are performed via pipes L and M with small diameters. This is because the amount of air required for attitude control is small. On the other hand, if "ΣV≧C", it is confirmed that the control valves 20 and 27 are turned off (step S9). In other words, a large diameter passage is selected as the supply/exhaust route. This is because a large amount of air is required for attitude control. After the large-diameter passage or the small-diameter passage is selected in step S8 or S9, roll control is performed in step S10 and subsequent steps. Then, the process proceeds to step S10, and it is determined whether each attitude control valve is in an on-operation, that is, whether or not the attitude control valve is in operation. If the determination in step S10 is "NO", the process advances to step S11, where each attitude control valve is turned on under the control of the control unit 34, and at the same time, step S11 is reached.
At 12, a timer of t ₂ (eg 0,1) sec is set. Here, for example, if the acceleration data (ΣV) of the acceleration G currently acting on the vehicle body is the leftward acceleration during a left turn or left turn, the vehicle body has a posture change to the right (right roll). Therefore, in order to perform posture control in a direction to counter this, the air intake solenoid valve 19 and the left wheel side solenoid valves 23 and 26 are turned on, respectively, in step S11. This allows the right wheel suspension unit RS1, RS to
The compressed air from the high-pressure side reserve tank 15a is supplied to the main air spring chamber 3 of No. 2 through the air supply solenoid valve 19, the small diameter L or large diameter air supply flow path set in step S8 or S9, and the air supply flow rate control. It begins to be supplied via valve 20 and solenoid valves 22 and 25. At the same time, the compressed air in the air spring chamber 3 of the left wheel suspension units LS1 and LS2 is transferred to the solenoid valves 23 and 2.
6. Exhaust flow rate control valve 27 and the above step S
The exhaust gas begins to be exhausted to the low-pressure side reserve tank 15b via the small diameter M or large diameter exhaust flow path set in step 8 or S9, the exhaust direction switching valve 28, and the residual pressure valve 29. As a result, attitude control is started in which the vehicle height of the right wheel side is displaced in the upward direction and the vehicle height of the left wheel side is displaced in the downward direction, and the vehicle height of the left and right sides of the vehicle body is shifted to the target range corresponding to the standard posture of the vehicle body. controlled in direction.

On the other hand, contrary to such right roll control, for example, if the acceleration data (ΣV) of the acceleration G currently acting on the vehicle body is rightward acceleration during a right turn or right turn, the vehicle body Since a posture change to the left (left roll) is about to occur, in order to perform posture control in a direction to counter this, in step S11, the air supply solenoid valve 19 and the right wheel side solenoid valves 22, 25 are activated. are turned on respectively. As a result, the main air spring chamber 3 of the left wheel suspension units LS1 and LS2 is
Compressed air from the high pressure side reserve tank 15a passes through the air supply solenoid valve 19, the small diameter L or large diameter air supply flow path set in step S8 or S9, the air supply flow rate control valve 20, and the solenoid valves 23, 26. Begins to be supplied via. At the same time, the compressed air in the main air spring chamber 3 of the right wheel suspension units RS1, RS2 is supplied to the solenoid valves 22, 25, the exhaust flow control valve 27, and the small diameter M or large diameter set in step S8 or S9. The exhaust gas begins to be exhausted to the reserve tank 15b on the low pressure side via the exhaust flow path of the diameter, the exhaust direction switching valve 28, and the residual pressure valve 29.
As a result, attitude control is started in which the vehicle height of the left wheel side is displaced in the upward direction and the vehicle height of the right wheel side is displaced in the downward direction, and the vehicle height of the left and right sides of the vehicle body is shifted to the target range corresponding to the standard posture of the vehicle body. controlled in direction.

In this way, the above steps S11 and S12
After the attitude control process is started, step S
13, it is determined whether t ₂ sec has elapsed since the timer was set in step S12. On the other hand, even if it is determined in step S10 to be YES, that is, each valve is already in the ON operation due to posture control, the process proceeds to step S13. If the determination is ``NO'' here, the process returns to step S1, and if the determination is ``YES'', the process proceeds to step S14. This step S1
4, it is determined whether the vehicle height average value () calculated every 6 msec in step S4 has reached the target range, and if the determination is "NO", the process returns to the above step. Steps S1-S1
0, S13, and S14 are repeatedly executed. As a result, the vehicle height of the left and right portions of the vehicle body changes so as to become closer to the target range corresponding to the reference posture of the vehicle body.

On the other hand, in this step S14, "YES",
In other words, when the constantly calculated average vehicle height () reaches the target range in step S4, and the attitude is controlled to the point where right roll or left roll is suppressed and the vehicle body becomes approximately horizontal, the process proceeds to step S15, and the attitude is controlled until the vehicle body is approximately horizontal. Shifts to control holding operation. This step S1
5, the solenoid valve 22 on the right wheel side,
25 or left wheel side solenoid valve 23, 26
remains on, the air intake solenoid valve 19 and the exhaust solenoid valve 30 are turned off, and the exhaust direction switching valve 28 is turned on, causing the main air spring chamber 3 of the left wheel suspension units LS1 and LS2 to be connected to the right wheel side. Suspension unit RS
1. The main air spring chambers 3 of the RS2 are each independently closed and held, so that the vehicle height of the left and right sides of the vehicle body is kept controlled within the target range and returned to step S16. move on. In step S16, it is determined whether the vehicle height average value () has reached a predetermined range narrower than the target range. If the determination in step S16 is "NO", the process returns to step S1. If the process proceeds to step S5 during such a holding operation of the attitude control valve, a ``YES'' determination is made, and the process proceeds to step S17. This step S1
In step 7, it is determined whether the value of the acceleration data (ΣV) that is constantly read and added in step S2 has changed in the direction of becoming larger, that is, whether a deeper turn has been made during a right or left turn, for example. "YES" here.
If it is determined that this is the case, the attitude control processing from step S7 onwards is executed again. Also, this step S17
If the determination is "NO" in step S1, the process returns to step S1.

By the way, if the determination in step S16 is ``YES'', the process advances to step S18.
Proceeding to step S18, all valves are turned off. This allows the right wheel suspension unit to
The main air spring chambers 3 of RS1 and RS2 and the main air spring chambers 3 of left wheel suspension units LS1 and LS2 are the front left and right solenoid valves 22 and 23 and the rear left and right solenoid valves 2, respectively.
5 and 26, the communication state is established. As a result, the left and right suspension units LS1, RS1, LS2,
The air pressures in the main air spring chambers 3 of each RS2 become equal, and the attitude control state caused by the right roll or left roll is released.

In addition, the first step S6 from the start
When it is determined that the acceleration data (ΣV) of the acceleration G acting on the vehicle body is less than the threshold value B, the process returns to step S1.
Return to

Therefore, attitude control is started when the acceleration acting on the vehicle body reaches a predetermined value or more, and the attitude control state is maintained when the vehicle height of the left and right sides of the vehicle body reaches the target vehicle height. Therefore, any attitude change that is about to occur in the vehicle body is reliably suppressed, regardless of its size.

[Effect of idea]

As described above, according to this invention, when the acceleration sensor detects acceleration in the left-right direction of the vehicle body that exceeds a predetermined value, the spring reaction force of each suspension unit is adjusted to control the posture in a direction that counters changes in the posture of the vehicle body. Then, when the vehicle height of the left and right sides of the vehicle reaches the target range corresponding to the standard posture of the vehicle, the spring reaction force of each suspension unit is maintained, and the vehicle height reaches a width wider than the target range. Since attitude control is canceled when a small predetermined range is reached, attitude control can always be performed with an appropriate amount of control, even if, for example, the inertia of the vehicle body changes due to an increase or decrease in the number of occupants, and the amount of attitude change varies greatly. become able to. As a result, posture changes occurring in the left-right direction of the vehicle body can be reliably suppressed under any conditions.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an electronically controlled suspension device according to an embodiment of this invention, and Fig. 2 A and B are 3
Diagram showing the opening/closing operation of a directional solenoid valve, 3rd
Figures A and B are diagrams showing the opening and closing operations of the two-way solenoid valve, and FIG. 4 is a flowchart showing the posture control operation of the electronically controlled suspension device according to an embodiment of the invention. LS1, LS2... Left wheel suspension unit, RS1, RS2... Right wheel suspension unit, 3... Air spring chamber, 15a, 15b... Reserve tank, 19... Air supply solenoid valve,
22, 25...Right wheel side solenoid valve, 23,
26...Left wheel side solenoid valve, 28...Exhaust direction switching valve, 30...Exhaust solenoid valve, 31L...Left wheel side vehicle height sensor, 31R...Right wheel side vehicle height sensor, 34...Control unit, 36... …Acceleration sensor.

Claims (1)

[Scope of utility model registration request] In a suspension device that includes a spring member interposed between a wheel and a vehicle body, and a spring force adjustment device that adjusts the spring force of this spring member, a G output voltage that corresponds to the acceleration of the vehicle body in the left and right direction is used. A sensor, a vehicle height sensor that detects the vehicle height of the left and right sides of the vehicle,
Output voltage V + α of this G sensor / time differential value
When V' exceeds a threshold, the spring force adjusting device is driven so that the spring member acts in a direction that opposes the horizontal posture control of the vehicle body, and the When the average vehicle height obtained by averaging the vehicle height at predetermined time intervals falls within the first target range, the spring force adjusting device is kept driven, and the average vehicle height is set to a second target range narrower than the first target range. 1. An electronically controlled suspension device comprising: a controller for controlling the return by using the spring force adjusting device when the above-described spring force adjustment device enters the above range.