JP3008622B2 - Wheel alignment control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel alignment control device for adjusting and controlling a state of a wheel alignment (caster, camber, toe-in) in an automobile.

[0002]

2. Description of the Related Art In general, in vehicles such as automobiles, suspension stiffness is tuned in advance by compliance steer (steering characteristics due to alignment control), riding comfort, and the like. It is not preferable to keep the suspension rigidity constant.

For example, in the case of an FF vehicle (front engine / front drive vehicle), at the time of acceleration / deceleration, the cornering power at the front is reduced by an amount corresponding to the acceleration / deceleration (driving force or braking force). Therefore, in the vicinity of a turning limit, on a slippery low μ road, or the like, the front wheels slip and the understeer tendency is increased. So, in the conventional suspension,
The front roll steer, front lateral force steer, camber, etc. increase the actual steering amount to cover the decrease in cornering power.

Further, in the case of an FR vehicle (rear engine / rear drive vehicle), at the time of acceleration / deceleration, the rear cornering power is reduced by an amount corresponding to the acceleration / deceleration (driving force or braking force). Therefore, near a turning limit, on a slippery low μ road, or the like, the rear wheel slips and the tendency of oversteering becomes strong. Thus, in the conventional suspension, the actual steering amount is increased by the rear roll steering, the rear lateral force steering, the camber, and the like to cover the decrease in the cornering power.

[0005]

However, FF
In both the car and the FR car, roll steer, lateral force steer, and the like steer against road surface disturbance, which causes deterioration of straightness, and the tuning must be compromised at an appropriate point. Therefore, it is desirable to improve the straightness and the turning performance by making it possible to use the compliance positively during the straight running and turning acceleration / deceleration while eliminating the steer change due to the lateral force, the longitudinal force, etc. during the normal straight running. It is rare.

The present invention has been devised in view of such problems, and has as its object to provide a wheel alignment control device capable of realizing an optimum compliance steer according to acceleration / deceleration.

[0007]

For this purpose, a wheel alignment control device according to the present invention comprises an alignment adjusting means for adjusting the wheel alignment of an automobile, and an acceleration state detecting means for detecting the acceleration state of the automobile.
Control means for controlling the alignment adjusting means so as to be able to suppress the steering characteristic change caused depending on the acceleration state based on the acceleration state information from the acceleration state detecting means is provided, the alignment adjusting means, a plurality of oil Have a room
Supplying and discharging pressurized oil to and from the plurality of oil chambers
Independent of the elastic member in multiple directions
And rigidity adjusting means for changing the rigidity.
The stiffness adjusting means may be operated in an acceleration state or a turning state of the vehicle.
In at least one direction of the elastic member.
Characterized in that it is configured to adjust the rigidity at which it is mounted .

[0008]

In the above-described wheel alignment control device of the present invention, the control means controls the alignment adjusting means based on the acceleration state information from the acceleration state detecting means, and the alignment adjusting means accelerates the wheel alignment of the vehicle. The adjustment is performed so that the change in the steering characteristic that occurs according to the state can be suppressed. At this time,
In the vehicle acceleration or turning conditions.
Control of the plurality of oil chambers provided in the elastic member.
At least one direction by supplying or discharging one of the pressure oils
Adjust the rigidity at.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a wheel alignment control device as one embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a structural diagram, FIGS. 2 and 3 are diagrams showing examples of maps for setting a target value of suspension stiffness with respect to acceleration / deceleration when the FF vehicle turns and goes straight, respectively. FIGS. FIGS. 6A to 6C show examples of a map for setting a target value of suspension rigidity with respect to acceleration / deceleration during turning and straight running. FIGS. 6A to 6C show a suspension bush with a rigidity adjusting mechanism constituting an alignment adjusting means in this embodiment. 6 (a) is a cross-sectional view of the rod as viewed from the axial direction, and FIG. 6 (b) is a view of VI in FIG. 6 (a).
FIG. 6C is a cross-sectional view taken along the arrow line b-VIb, and FIG.
FIG. 7 is a cross-sectional view taken along the line c-VIc, FIG. 7 is a flowchart for explaining the control operation, and FIGS. 8 to 13 each show an example of mounting the suspension bush on the suspension in the present embodiment. FIG. 9 is a schematic view showing the mounting example in the vehicle length direction, FIG. 9 is a schematic plan view showing the mounting example, and FIG. 10 is a detailed view showing the mounting example in the vehicle length direction. 12 is a plan view of a main part and a side view of a main part showing a mounting example, respectively. FIG. 13 is a schematic perspective view showing another mounting example viewed in the vehicle length direction. FIG. 14 is a wheel alignment of the present embodiment. 9 is a graph illustrating an example of a response from a current value to a target value when the suspension rigidity is changed by the control device.

In this embodiment, in order to adjust the wheel alignment (caster, camber, toe-in) of the automobile by adjusting the suspension rigidity, a suspension bush 1 having a rigidity adjusting mechanism as shown in FIGS.
Is used. This suspension bush 1 with a rigidity adjusting mechanism is provided on a mounting portion of an automobile suspension to a vehicle body, and as shown in FIGS. 6A to 6C, a case 2 mounted on the vehicle body side and a suspension side , And rubber members 4 and 6 for elastically supporting the shaft 3 in the case 2.

The rubber member 4 is formed of the first material in the case 2.
6 (in the vertical direction in FIG. 6A),
Both ends are fixed to the inner wall of the case 2, and spaces (first oil chambers) 7 a and 7 b are formed on both sides of the rubber body 4. Thus, the rubber body 4 elastically supports the shaft 3 inside the rubber body 4 in the first direction. Also, the rubber body 6
Are provided in the middle part of the inner case 5 built in the rubber body 4 in the second direction (the left-right direction in FIG. 6A), with both ends fixed to the inner wall of the case 5. Spaces (second oil chambers) 8a and 8b are formed on both sides of the rubber body 6. Thus, the rubber body 6 elastically supports the shaft 3 inside the rubber body 6 in the second direction.

The rigidity in the first direction changes according to the oil pressure supplied to the oil chambers 7a and 7b.
The support rigidity in the second direction changes according to the hydraulic pressure supplied to the insides a and 8b. Reference numeral 9 denotes a reinforcing member built in each of the rubber members 4 and 6, and the reinforcing members 9 make the rubber members 4 and 6 have a certain tension (rigidity). 20a to 20d are each oil chamber 7
a, 7b, 8a, 8b are hydraulic supply / discharge ports.

Such a suspension bush 1 with a rigidity adjusting mechanism can be installed on various types of suspensions. For example, when it is installed on a strut type suspension, as shown in FIGS. Between each inner end of the vehicle and the vehicle body 26, for example, the shaft 3
Can be installed facing vertically. In the drawing, 21 is a wheel, 22 is a strut, 27 is a rubber bush that supports the inner end of the strut 22 so as to be rotatable around the vehicle length direction axis, and 25 is a bush that connects the bush 27 and the shaft 3 of the suspension bush 1. It is a joint joint. More specifically, it is configured as shown in FIGS. In the drawings, the same reference numerals as those in FIGS. 8 and 9 denote the same parts, reference numeral 21a denotes a knuckle, 23 denotes a joint between the knuckle 21a and the outer end of the lower arm 24, and 28 denotes a spring.

When the suspension bush 1 is mounted on a wishbone type (double wishbone type in FIG. 13) suspension, for example, as shown in FIG.
Not only the inner ends of the lower arm 30 but also the upper arm 3
It is also conceivable to install them at the respective inner ends. The details of the connecting portion can be configured almost similarly to the strut type example (see FIGS. 11 and 12).

In the present embodiment, the suspension bush 1 is installed in the first direction (vertical direction in FIG. 6A) with the shaft 3 oriented vertically as described above. Although the second direction (the left-right direction in FIG. 6A) is installed in the vehicle length direction, the installation posture of the suspension bush 1 is not limited to this. May be installed in the vehicle length direction and the second direction may be installed in the vehicle width direction, or the shaft 3 may be installed in another direction.

As described above, the first and second oil chambers 7a, 7b, 8 of the suspension bush 1 with rigidity adjustment mechanisms mounted on the front, rear, left, and right suspensions of the vehicle as described above.
As shown in FIG. 1, the oil chambers 7a, 7b,
A hydraulic control system 10 for controlling the internal oil pressure of the inside 8a, 8b is connected, and the oil chambers 7a, 7b, 8a, 8b and the hydraulic control system 10 constitute a rigidity adjusting mechanism 1A for adjusting the suspension rigidity. ing. The stiffness adjusting mechanism 1A functions as an alignment adjusting unit that can adjust the wheel alignment (caster, camber, toe-in) of the automobile.

The suspension bush 1 functions as a rigidity adjusting actuator.
The suspension bush 1 is also called an actuator. Also, in FIG.
Although only one hydraulic control system 10 and one hydraulic control system 10 are shown, actuators 1 are provided for each of four front, rear, left and right suspensions of the vehicle, and the front actuator 1 and the rear actuator 1 are independent. A hydraulic control system 10 is provided to separately control the front and rear suspension stiffness.

The wheel alignment control device of this embodiment including the hydraulic control system 10 is configured as shown in FIG. 1, and in FIG.
The control valves 11 are connected to a suspension rigidity setting unit 11a and a hydraulic control amount setting unit 1 described later.
1b is a controller as a control means for outputting control signals to the control valves 10a and 10b. Reference numeral 12 denotes a group of sensors connected to the controller 11. The sensor group 12 includes at least the acceleration / deceleration (acceleration state) of the vehicle body. A vehicle speed sensor 12a as an acceleration state detecting means for detecting a vehicle speed to be detected, and a steering angle sensor 12b for detecting a steering angle of the steering to determine whether or not the vehicle is turning.
And are included. Reference numeral 13 denotes an orifice, 14 denotes an oil pump, 15 and 18 denote accumulators, 16 denotes a relief valve, 17 denotes a one-way valve, and 19 denotes an oil reservoir.

The control valves 10a, 10b are provided with oil chambers 7a,
7b, 8a, 8b and the accumulator 18 side in the open state and the supply / discharge ports 2 of the oil chambers 7a, 7b, 8a, 8b.
0a, 20b, 20c, 20 and the oil chambers 7a, 7 from the supply / discharge ports 20a, 20b, 20c, 20.
b, 8a, and 8b, which can take a drain state for discharging the hydraulic pressure, and is controlled by the controller 11 to any one of these states.

The controller 11 has a vehicle speed sensor 1
FIG. 7 based on the information from the steering angle sensor 2b and the steering angle sensor 12b.
Control valves 10a, 10b according to the flowchart shown in FIG.
And has the suspension rigidity setting unit 11a and the hydraulic control amount setting unit 11b as described above. The suspension stiffness setting unit 11a includes the vehicle speed sensor 1
Calculating the acceleration / deceleration of the vehicle based on the detection result of 2a,
A target value of the suspension stiffness with respect to the acceleration / deceleration of the vehicle is set using the map I for turning shown in FIG. 2 or 4 and the map II for straight running shown in FIG. 3 or FIG. The hydraulic control amount setting unit 11b sets control amounts of the control valves 10a and 10b necessary to obtain the target value of the suspension rigidity based on the target value of the suspension rigidity set by the suspension rigidity setting unit 11a.
A control signal corresponding to the control amount is transmitted to each control valve 10a, 1
0b.

Here, the maps shown in FIG. 2 and FIG.
The maps shown in FIGS. 4 and 5 are for an FR vehicle, and these maps are described in detail later.
The suspension stiffness setting unit 11 sets a target value of the suspension stiffness for each of the FF vehicle and the FR vehicle so as to suppress a change in the steering characteristic generated according to the acceleration / deceleration.
a in the memory unit (not shown).

In this embodiment, the control valves 10a,
If the valve 10b is open, the oil driven by the oil pump 14 is appropriately adjusted in pressure by the valves 16 and 17 and stored in the accumulator 18, and the control valve 10a or 10
b, the supply / discharge ports 20a, 20b or the supply / discharge ports 20c, 20
Through d, it is supplied into each oil chamber 7a, 7b or 8a, 8b of the actuator (suspension bush) 1. The control valve 10a or 10b is connected to each oil chamber 7
When the inside of a, 7b or 8a, 8b reaches a predetermined pressure, it is closed, whereby the pressure in each of the oil chambers 7a, 7b or 8a, 8b is kept at a predetermined level. Further, when the control valve 10a or 10b is set to the drain state, the oil in the oil chambers 7a, 7b or 8a, 8b is discharged, and the pressure in the oil chambers 7a, 7b or 8a, 8b decreases. ing.

Therefore, the actuator 1 of the present embodiment
Then, for example, the first pressure is adjusted by adjusting the internal pressure of the oil chambers 7a and 7b.
(In this example, the vehicle width direction, that is, the lateral direction) is adjusted, and the rigidity in the second direction (in this example, the vehicle length direction, that is, the front-rear direction) is adjusted by adjusting the internal pressure of the oil chambers 8a, 8b. Is done. Specifically, the rigidity increases as the internal pressure increases, and the rigidity decreases as the internal pressure decreases.

As a result, the support rigidity for restraining the inner end of the lower arm 24 of the suspension can be adjusted independently from two directions (lateral direction and front-rear direction), and the suspension rigidity can be adjusted two-dimensionally. I can do it. Since the binding force between the suspension and the vehicle body 26 also works at other joints, the direction of suspension rigidity adjustment when the support rigidity of the inner end of the lower arm 24 is adjusted in the vehicle width direction or the vehicle length direction is the same. Although not necessarily, the suspension rigidity can be adjusted at least two-dimensionally by adjusting the rigidity of the lower arm 24 from two different directions.

Since the wheel alignment control device according to one embodiment of the present invention is configured as described above, the controller 11 controls the controller 11 based on the information from the vehicle speed sensor 12a and the steering angle sensor 12b in accordance with the flowchart shown in FIG. By controlling the control valves 10a and 10b for each of the front and rear hydraulic control systems 10, the pressure in the oil chambers 7a, 7b, 8a and 8b in each of the front and rear actuators 1 is adjusted, and the front and rear suspension rigidity is adjusted. Then, the wheel alignment of the automobile is adjusted so as to suppress the change in the steering characteristic caused by the acceleration / deceleration.

That is, in the apparatus according to the present embodiment, first, initial settings such as initialization of the controller 11 and setting of the maps I and II are performed (step S1), and then sensors such as the vehicle speed sensor 12a and the steering angle sensor 12b are used. The detection value from the group 12 is read (step S2). And the vehicle speed sensor 1
After the acceleration / deceleration (acceleration state) is calculated based on the vehicle speed information from 2a (step S3), it is determined whether or not the vehicle is turning based on the steering angle information from the steering angle sensor 12b ( Step S4).

When it is determined in step S4 that the vehicle is turning, the front and rear suspension stiffnesses are set in accordance with the acceleration / deceleration calculated in step S3 by using the map I shown in FIG. 2 or FIG. (Step S
5). On the other hand, if it is determined in step S4 that the vehicle is not turning, that is, the vehicle is traveling straight ahead, the front and rear suspensions are determined according to the acceleration / deceleration calculated in step S3 using map II shown in FIG. 3 or FIG. The rigidity is set (step S6).

After the suspension stiffness is set by the suspension stiffness setting unit 11a of the controller 11, the hydraulic control amount setting unit 11b obtains the target value based on the set target value of the suspension stiffness. The control amount of each control valve 10a, 10b necessary for the control is set, and a control signal corresponding to the control amount is output to each control valve 10a, 10b. Thereby, the pressure in each of the oil chambers 7a, 7b, 8a, 8b of the actuator 1 is adjusted, and the suspension rigidity is adjusted.

At this time, in the actuator 1 of this embodiment, the rigidity can be independently adjusted in the lateral direction and the front-back direction of the vehicle as described above. It is performed simultaneously in both the direction and the front-back direction. That is, when increasing the suspension rigidity, the rigidity is increased in both directions, and when decreasing the suspension rigidity, the rigidity is decreased in both directions.

When changing the suspension stiffness from the current value to the target value, the time constant is appropriately set in response to the vehicle speed or the steering angular speed. For example, as shown in FIG.
The change from the current value to the target value is performed smoothly. That is,
When driving at high speed or when the steering angular velocity is large (when turning sharply)
It is thought that a quick change in suspension stiffness is necessary for the vehicle, so while the time constant is small, when running at low speed or the steering angular velocity is small, there is no problem even if the suspension stiffness is changed gently. I do. In addition,
The setting of the time constant when the suspension stiffness is changed is performed by changing the duty ratio of the control valves 10a and 10b or by providing a variable throttle valve and adjusting it.

By the way, between the suspension stiffness and the cornering power, as the suspension stiffness increases, the steering amount (displacement amount) decreases, and the increase in the tire equivalent cornering power decreases. And the increase in tire equivalent cornering power increases. Further, there is a relationship between the cornering power and the change in the steering characteristics that the oversteering tendency occurs when the front wheel cornering power is large, while the understeering tendency occurs when the rear wheel cornering power is large.

In the present embodiment, based on these relationships, and basically taking into account that the FF vehicle tends to understeer and the FR vehicle tends to oversteer, and that the steering characteristic changes according to the acceleration / deceleration, The target values of the suspension stiffness before and after the change in the steering characteristic (oversteer tendency, understeer tendency) generated according to the acceleration / deceleration are set as maps shown in FIGS.

As described above, in steps S5 and S6 in FIG. 7, the target values of the front and rear suspension stiffness are set based on these maps I and II, respectively. The adjustment is made by the mechanisms shown in FIGS. 1 and 6, respectively. In this embodiment, since the front and rear suspension stiffnesses are separately adjusted, in FIG. 2 to FIG. 5, the front side suspension stiffness is denoted by a symbol F and is indicated by a solid line, while the rear side suspension stiffness is indicated by a solid line. Sign R
And are indicated by broken lines.

When setting the map, basically, the reduction control of the tire equivalent cornering power of the rear wheels (that is, the control of increasing the suspension stiffness), which leads to the reduction of the limit performance, is not performed. Further, when traveling straight, it is fundamental to increase the straight traveling stability by forming a toe-in. As will be described later, the suspension rigidity is reduced to make the toe-in by longitudinal force steering.

Hereinafter, each map will be described in detail. A map I for setting a target value of the suspension rigidity with respect to the acceleration / deceleration when the FF vehicle is turning is given as shown in FIG. In a front-wheel drive vehicle, the driving force of the front wheels (drive wheels) increases as the acceleration increases during turning acceleration, and the tire equivalent cornering power of the front wheels decreases and the understeering tendency progresses.
As shown by the addition, the decrease in the front-side suspension rigidity is compensated for by the decrease in the cornering power of the front wheels, and the tendency to understeer is suppressed.

On the other hand, when the FF vehicle is turning and decelerating (during braking), both the front and rear wheels receive a braking force, so that the tire equivalent cornering power of both the front and rear wheels decreases. This decreasing tendency is greater for the front wheels that receive a greater braking force than for the rear wheels. Therefore, as indicated by reference numerals F and R in the left half of FIG. While significantly lowering the suspension stiffness, the decrease in the cornering power of both the front and rear wheels is compensated for, the understeer tendency is suppressed for the front wheels, and the oversteer tendency is suppressed for the rear wheels.

A map II for setting a target value of the suspension rigidity with respect to the acceleration / deceleration when the FF vehicle is traveling straight ahead is as follows:
It is provided as shown in FIG. In a front-wheel drive vehicle, the tire equivalent cornering power of the front wheels decreases as the driving force of the front wheels, which is the driving wheel, increases during the straight running acceleration, the understeer tendency advances, the straight running stability increases, and the straight running state is favorable. However, if the acceleration is too large (when suddenly starting)
Since the understeer tendency is excessively advanced, the front wheel cornering power is increased by slightly lowering the front suspension rigidity to suppress the understeer tendency as shown by the reference symbol F in the right half of FIG. are doing. In addition, the rear wheel at the time of straight acceleration accelerates, the cornering power decreases due to the force of the backward lean as the acceleration increases,
Since the oversteering tendency progresses, the right half of FIG.
As shown by the suffix, the cornering power of the rear wheels is supplemented by lowering the suspension rigidity on the rear side, and the tendency to oversteer is suppressed.

On the other hand, when the FF vehicle is straightly decelerated (during braking), since the front wheel and the rear wheel receive the braking force, the tire equivalent cornering power of both the front wheel and the rear wheel decreases. The front wheels are in a favorable condition because the understeer tendency tends to increase and the straight running stability increases due to the decrease in tire equivalent cornering power. However, when the deceleration is too large (during sudden deceleration)
Since the understeer tendency is excessively advanced, the front wheel cornering power is increased by slightly lowering the suspension rigidity on the front side to suppress the understeer tendency, as indicated by reference numeral F in the left half of FIG. are doing. In addition, the rear wheel at the time of straight-line deceleration becomes more buoyant as the deceleration increases, and the oversteering tendency progresses. Therefore, as shown by the symbol R in the left half of FIG. By lowering it, the cornering power of the rear wheel is supplemented and the tendency to oversteer is suppressed.

A map I for setting a target value of the suspension stiffness with respect to the acceleration / deceleration during the turning of the FR vehicle is given as shown in FIG. In an FR vehicle, the driving force of the rear wheels (drive wheels) increases as the acceleration increases during turning acceleration, and the tire equivalent cornering power of the rear wheels decreases and the oversteering tendency progresses. As shown by the symbol F, the reduction in the rear suspension stiffness is compensated for by the decrease in the cornering power of the rear wheels, and the tendency to oversteer is suppressed.

On the other hand, when the FR vehicle is turning and decelerating (during braking), as in the case of the FF vehicle shown in FIG. 2, both the front and rear wheels receive a braking force, so that both the front and rear wheels have tire equivalent cornering. Power decreases. This decreasing tendency is greater for the front wheels that receive a greater braking force than for the rear wheels. Therefore, as indicated by reference numerals F and R in the left half of FIG. While significantly lowering the suspension stiffness, the decrease in the cornering power of both the front and rear wheels is compensated for, the understeer tendency is suppressed for the front wheels, and the oversteer tendency is suppressed for the rear wheels.

A map II for setting a target value of the suspension stiffness with respect to the acceleration / deceleration when the FR vehicle travels straight ahead is as follows:
Provided as shown in FIG. In an FR vehicle, the driving force of the rear wheels (drive wheels) increases as the acceleration increases during straight-ahead acceleration, and the tire equivalent cornering power of the rear wheels decreases and the oversteer tendency greatly increases.
As shown by the reference symbol R in the right half of the figure, the rear suspension stiffness is significantly reduced to compensate for the decrease in the cornering power of the rear wheels, thereby suppressing the tendency to oversteer. In addition, the front wheels at the time of straight-line acceleration are more likely to float and the oversteering tendency is advanced as the acceleration is increased. Therefore, as shown by a reference F in the right half of FIG. By increasing it, the cornering power of the front wheels is reduced, and the tendency to oversteer is suppressed.

On the other hand, at the time of straight-forward deceleration (at the time of braking) of the FR vehicle, since the front wheel and the rear wheel receive the braking force as in the case of the FF vehicle shown in FIG. Power decreases. As for the front wheels, the understeer tendency progresses due to the decrease in the tire equivalent cornering power, and the straight running stability increases.
If the deceleration is too large (at the time of rapid deceleration), the understeer tendency is too advanced, and as shown by the reference F in the left half of FIG. The cornering power is increased to reduce the tendency to understeer. In addition, the rear wheel at the time of straight forward deceleration becomes more buoyant as the deceleration increases, and the tendency of oversteering progresses. Therefore, as shown by the symbol R in the left half of FIG. By lowering it, the cornering power of the rear wheel is supplemented and the tendency to oversteer is suppressed.

As described above, according to the wheel alignment control device of the present embodiment, the maps I,
II, a target value of the front and rear suspension stiffness is set, and each of the front and rear actuators 1 is set based on the target value.
By adjusting the pressure in the oil chambers 7a, 7b, 8a, 8b by the hydraulic control system 10, the suspension rigidity is controlled so as to suppress the change in the steer characteristics (oversteer tendency, understeer tendency) caused by the acceleration / deceleration. An adjustment is made to adjust the wheel alignment. Ri by <br/> thereto, the lateral force during normal straight, while eliminating the steering change due longitudinal force or the like, can achieve optimal compliance steer during straight running and turning during the acceleration and deceleration, improved straightness and turning performance There are advantages that can contribute to

In the above-described embodiment, the vehicle speed sensor 12a is used as the acceleration state detecting means.
Although the acceleration state is detected by calculating the acceleration / deceleration from the detection result of 2a, other acceleration state detection means such as a G sensor may be used. In the above-described embodiment, the suspension rigidity is adjusted in both the lateral direction and the front-rear direction of the actuator 1 at the same time. Since the stiffness can be adjusted independently for each, when adjusting the suspension stiffness when going straight, the longitudinal stiffness of the actuator 1 is adjusted to control the longitudinal force steer, while the suspension is adjusted when turning In doing so, the lateral force steer may be controlled by adjusting the lateral rigidity of the actuator 1.

[0045]

[0046]

As described above in detail, according to the wheel alignment control device of the present invention, the alignment adjusting means for adjusting the wheel alignment of the vehicle and the acceleration state detecting means for detecting the acceleration state of the vehicle are provided. In addition, control means for controlling the alignment adjusting means based on the acceleration state information from the acceleration state detection means so as to suppress a change in the steer characteristic generated according to the acceleration state is provided.
Provided, and the alignment adjusting means is provided with a plurality of oil chambers.
Supply and discharge pressure oil to and from the plurality of oil chambers
By doing so, each of the elastic members
Including rigidity adjusting means for independently changing rigidity
And adjusting the rigidity adjusting means to the acceleration state or the turning state of the vehicle.
Control according to the turning state, at least one of the elastic members
Extremely simple configuration that adjusts the rigidity in the direction makes it possible to obtain the optimal compliance steer according to the acceleration / deceleration, and eliminates steer changes due to lateral force, longitudinal force, etc. during normal straight running. At the time of acceleration / deceleration, there is an advantage that the compliance steer control can be positively used and the straightness and the turning performance can be improved. In addition, each of the elastic members is independent in multiple directions.
To adjust the suspension rigidity.
Depending on the direction, adjust the rigidity of the elastic member in one direction
You can get the required compliance steer.
The advantage is that the degree of freedom in adjusting the suspension rigidity is high.
There is also.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a wheel alignment control device as one embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a map for setting a target value of suspension stiffness with respect to acceleration / deceleration when the FF vehicle is turning.

FIG. 3 is a diagram showing an example of a map for setting a target value of suspension rigidity with respect to acceleration / deceleration when the FF vehicle is traveling straight.

FIG. 4 is a diagram showing an example of a map for setting a target value of suspension stiffness with respect to acceleration / deceleration during turning of an FR vehicle.

FIG. 5 is a diagram illustrating an example of a map for setting a target value of suspension rigidity with respect to acceleration / deceleration when the FR vehicle is traveling straight.

6A and 6B are diagrams showing a suspension bush with a rigidity adjusting mechanism constituting an alignment adjusting means in the present embodiment, wherein FIG. 6A is a cross-sectional view of the rod viewed from the axial direction of the rod;
(B) is a sectional view taken along the line VIb-VIb of (a), and (c) is a sectional view taken along the line VIc-VIc of (a).

FIG. 7 is a flowchart for explaining a control operation of the wheel alignment control device of the present embodiment.

FIG. 8 is a schematic diagram showing an example of mounting a suspension bush on a suspension according to the present embodiment as viewed in a vehicle length direction.

FIG. 9 is a schematic plan view showing an example of mounting a suspension bush on a suspension in the present embodiment.

FIG. 10 is a detailed view showing an example of mounting the suspension bush on the suspension according to the present embodiment as viewed in the vehicle length direction.

FIG. 11 is a plan view of relevant parts showing an example of mounting a suspension bush on a suspension in the present embodiment.

FIG. 12 is a main part side view showing an example of mounting a suspension bush on a suspension in the embodiment.

FIG. 13 is a schematic perspective view showing another example of mounting the suspension bush on the suspension according to the present embodiment when viewed in the vehicle length direction.

FIG. 14 is a graph showing an example of a response from a current value to a target value when the suspension stiffness is changed by the wheel alignment control device of the present embodiment.

[Explanation of symbols]

Reference Signs List 1 suspension bush with rigidity adjusting mechanism (rigidity adjusting actuator) 1A rigidity adjusting mechanism as alignment adjusting means 2 case 3 shaft 4,6 rubber body (elastic support member) 5 inner case 7a, 7b space (first oil chamber) 8a, 8b Space (second oil chamber) 9 Reinforcement material 10 Hydraulic control system 10a, 10b Control valve 11 Controller as control means 11a Suspension rigidity setting unit 11b Hydraulic control amount setting unit 12 Sensor group 12a Acceleration state detecting means Vehicle speed sensor 12b Steering angle sensor 13 Orifice 14 Oil pump 15, 18 Accumulator 16 Relief valve 17 One-way valve 19 Oil reservoir 20a to 20d Supply / discharge port 21 Wheel 21a Knuckle 22 Strut 23 Joint 24, 30 Lower arm 25 Joining joint Cement 26 body 27 bush 28 spring 29 the upper arm

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takao Morita Mitsubishi Motors Corporation (56-33-8), Shiba 5-chome, Minato-ku, Tokyo (56) References JP-A-62-289414 (JP, A) JP-A-3-148318 (JP, A) JP-A-2-306815 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60G 17/015

Claims (1)

(57) [Claims] 1. An acceleration adjusting means for adjusting a wheel alignment of an automobile, and an acceleration detecting means for detecting an accelerating state of the automobile, wherein an acceleration state is set based on the acceleration state information from the accelerating state detecting means. elastic response control means for controlling the alignment adjusting means so as to be able to suppress the steering characteristic change caused is provided, the alignment adjusting means, having a plurality of oil chambers
By supplying and discharging pressurized oil to the members and the plurality of oil chambers
The rigid members are independently rigid in a plurality of directions of the elastic member.
And a stiffness adjusting means for changing the stiffness of the vehicle.
Control according to the state of the elastic member in at least one direction.
A wheel alignment control device configured to adjust rigidity in the wheel alignment.