JPH05178049A - Wheel alignment controller - Google Patents

Abstract

PURPOSE:To provide a wheel alignment controller for adjusting controllably the wheel alignment (caster, camber, toe-in) condition in an automobile to realize an optimum compliance steer according to the acceleration or deceleration condition. CONSTITUTION:A control means 11 provided with an alignment adjusting means 1A capable of adjusting the wheel alignment of an automobile and an acceleration condition detecting means 12a for detecting the acceleration condition of automobile controls the alignment adjusting means 1A to restrain a change in a steering property generated according to the acceleration condition on the basis of the acceleration condition information from the acceleration condition detecting means 12a.

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 the state of wheel alignment (caster, camber, toe-in) in an automobile.

[0002]

2. Description of the Related Art Generally, in a vehicle such as an automobile, suspension rigidity is tuned in advance according to compliance steering (steering characteristics caused by alignment control), riding comfort, etc. However, since steering characteristics change during acceleration / deceleration, It is not desirable if the suspension rigidity setting remains constant.

For example, in the case of an FF vehicle (front engine / front drive vehicle), at the time of acceleration / deceleration, the front cornering power is reduced by the amount of acceleration / deceleration (driving force or braking force). As a result, the front wheel slips and the understeer tendency becomes stronger near the turning limit or on a slippery low μ road. So, in the conventional suspension,
Front roll steer, front lateral force steer, camber, etc. increase the actual steering amount to cover the decrease in cornering power.

In the case of FR vehicles (rear engine / rear drive vehicle), the rear cornering power is reduced by the amount of acceleration / deceleration (driving force or braking force) during acceleration / deceleration. As a result, the rear wheel slips and the oversteer tendency becomes stronger near the turning limit or on a slippery low μ road. Therefore, in the conventional suspension, the actual steering amount is increased by the rear roll steer, the rear lateral force steer, the camber, etc. to cover the decrease in the cornering power.

[0005]

However, the FF
In both cars and FR cars, roll steer, lateral force steer, etc. steer against road surface disturbances, which causes deterioration of straightness, and there is no choice but to compromise on appropriate points for tuning. Therefore, it is desirable to improve the straightness and turning performance by eliminating the change in steering due to lateral force, longitudinal force, etc. during normal straightening, while making positive use of compliance during acceleration / deceleration during straightening and turning. It is rare.

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

[0007]

For this reason, the wheel alignment control device of the present invention comprises an alignment adjusting means for adjusting the wheel alignment of the automobile and an acceleration state detecting means for detecting the acceleration state of the automobile.
It is characterized in that a control means is provided for controlling the alignment adjusting means so as to suppress a steer characteristic change which occurs according to the acceleration state based on the acceleration state information from the acceleration state detecting means.

[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 automobile. It is adjusted so as to suppress the steer characteristic change that occurs depending on the state.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A wheel alignment control apparatus as an embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a configuration diagram thereof, FIGS. 2 and 3 are diagrams showing examples of maps for setting a target value of suspension rigidity with respect to acceleration / deceleration during turning and straight running of an FF vehicle, and FIGS. FIGS. 6A to 6C are diagrams showing an example of a map for setting a target value of suspension rigidity with respect to acceleration / deceleration during turning and straight traveling, and FIGS. 6A to 6C show a suspension bush with a rigidity adjusting mechanism which constitutes an alignment adjusting means in the present embodiment. 6A is a cross-sectional view as seen from the axial direction of the rod, and FIG. 6B is a VI of FIG. 6A.
b-VIb arrow sectional view, FIG.6 (c) is VI of FIG.6 (a)
FIG. 7 is a sectional view taken along the line c-VIc, FIG. 7 is a flowchart for explaining the control operation thereof, and FIGS. 8 to 13 show examples of mounting the suspension bush on the suspension in the present embodiment. Is a schematic view showing the mounting example in the vehicle length direction, FIG. 9 is a schematic plan view showing the mounting example, FIG. 10 is a detailed view showing the mounting example in the vehicle length direction, FIG. 12 is a plan view of a main part showing a mounting example thereof, a side view of the main part, FIG. 13 is a schematic perspective view showing another mounting example in the vehicle length direction, and FIG. 14 is a wheel alignment of the present embodiment. 6 is a graph showing an example of response from a current value to a target value when 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 with a rigidity adjusting mechanism as shown in FIGS. 6 (a) to 6 (c).
Is used. The suspension bushing 1 with a rigidity adjusting mechanism is provided at a mounting portion of an automobile suspension to a vehicle body. As shown in FIGS. 6A to 6C, a case 2 mounted on the vehicle body side and a suspension side And a rubber body 4, 6 elastically supporting the shaft 3 in the case 2.

Of these, the rubber member 4 is the first member in the case 2.
In the middle part of the direction [up and down direction in FIG. 6 (a)]
Both ends are fixedly provided to the inner wall of the case 2, and spaces (first oil chambers) 7a and 7b are formed on both sides of the rubber body 4. As a result, the rubber body 4 elastically supports the shaft 3 inside thereof in the first direction. Also, the rubber body 6
Is provided by fixing both ends to the inner wall of the case 5 at an intermediate portion in the second direction (the left-right direction in FIG. 6A) in the inner case 5 built in the rubber body 4, Spaces (second oil chambers) 8a and 8b are formed on both sides of the rubber body 6. As a result, the rubber body 6 elastically supports the shaft 3 therein in the second direction.

The support rigidity in the first direction changes in accordance with the hydraulic pressure supplied into the oil chambers 7a and 7b, and the oil chamber 8
The support rigidity in the second direction changes according to the hydraulic pressure supplied to the insides of a and 8b. Reference numeral 9 is a reinforcing member built in each rubber body 4, 6, and the reinforcing member 9 causes the rubber bodies 4, 6 to have a certain tension (rigidity). Further, 20a to 20d are each oil chamber 7
It is a supply / discharge port for hydraulic pressure to a, 7b, 8a, 8b.

The suspension bush 1 with such a rigidity adjusting mechanism can be installed in various types of suspensions. For example, when it is installed in a strut type suspension, as shown in FIGS. 8 and 9, the front and rear lower arms 24 are provided. Between each inner end of the vehicle body 26 and the inner end of the
Can be installed vertically. In the figure, 21 is a wheel, 22 is a strut, 27 is a rubber bush that rotatably supports the inner end of the strut 22 about the vehicle longitudinal axis, and 25 connects the bush 27 and the shaft 3 of the suspension bush 1. It is a joint. Further, in detail, the configuration is as shown in FIGS. In the drawings, the same reference numerals as those in FIGS. 8 and 9 indicate the same things, reference numeral 21a indicates a knuckle, 23 indicates a joint between the knuckle 21a and the outer end of the lower arm 24, and 28 indicates a spring.

When the suspension bush 1 is installed in, for example, a wishbone type (double wishbone type in FIG. 13) suspension, as shown in FIG.
Not only the inner ends of the lower arm 30 but also the upper arm 3
It is conceivable to install it at each inner end of 1. The details of the connecting portion can be configured in substantially the same manner as the strut type example (see FIGS. 11 and 12).

Further, in this embodiment, the suspension bush 1 is installed in the vehicle width in the first direction [vertical direction in FIG. 6 (a)] with the shaft 3 oriented vertically as described above. Direction, the second direction (the left-right direction in FIG. 6A) is installed in the vehicle length direction, but the installation posture of the suspension bush 1 is not limited to this, and for example, the first direction Can be installed in the vehicle length direction, the second direction in the vehicle width direction, and the shaft 3 can be installed in the other direction.

Now, as described above, the first and second oil chambers 7a, 7b, 8 of the suspension bush 1 with each rigidity adjusting mechanism mounted on the front, rear, left and right suspensions of the automobile.
a and 8b, as shown in FIG. 1, each oil chamber 7a, 7b,
A hydraulic control system 10 for controlling the internal hydraulic pressure of 8a, 8b is connected, and a rigidity adjusting mechanism 1A for adjusting suspension rigidity is configured from the oil chambers 7a, 7b, 8a, 8b and the hydraulic control system 10. ing. The rigidity adjusting mechanism 1A functions as an alignment adjusting means capable of adjusting the wheel alignment (caster, camber, toe-in) of the automobile.

The suspension bush 1 functions as a rigidity adjusting actuator.
The suspension bush 1 will also be referred to as an actuator. Further, in FIG. 1, the actuator 1
Although only one hydraulic control system 10 is shown in the figure, in reality, actuators 1 are provided for each of four front, rear, left and right suspensions of the vehicle, and the front side actuator 1 and the rear side actuator 1 are independent. The hydraulic control system 10 is provided so that front and rear suspension rigidity can be controlled separately.

The wheel alignment control device of this embodiment including the hydraulic control system 10 is constructed as shown in FIG. 1. In FIG. 1, 10a and 10b are the supply / discharge ports 20.
A control valve connected to a to 20d, 11 is a suspension rigidity setting unit 11a and a hydraulic control amount setting unit 1 which will be described later.
1b is a controller as a control means for outputting a control signal to the control valves 10a and 10b, and 12 is a sensor group connected to the controller 11. The sensor group 12 has at least an acceleration / deceleration (acceleration state) of the vehicle body. A vehicle speed sensor 12a as an acceleration state detecting means for detecting the vehicle speed to be detected, and a steering angle sensor 12b for detecting the steering angle of the steering to determine whether or not the vehicle is turning.
And are included. Further, 13 is an orifice, 14 is an oil pump, 15 and 18 are accumulators, 16 is a relief valve, 17 is a one-way valve, and 19 is an oil reservoir.

The control valves 10a, 10b are connected to the oil chamber 7a,
7b, 8a, 8b and the accumulator 18 side communicating state, the oil chamber 7a, 7b, 8a, 8b supply and discharge port 2
0a, 20b, 20c, 20 closed state, and the oil chambers 7a, 7 from the supply / discharge ports 20a, 20b, 20c, 20.
It has a structure capable of taking a drain state for discharging the hydraulic pressure in b, 8a, 8b, and is controlled by the controller 11 to any one of these states.

Further, the controller 11 uses the vehicle speed sensor 1
2a and the information from the steering angle sensor 12b.
Control valves 10a and 10b according to the flowchart shown in FIG.
As described above, the suspension rigidity setting unit 11a and the hydraulic pressure control amount setting unit 11b are provided. The suspension rigidity setting unit 11a is used for the vehicle speed sensor 1
Calculate the acceleration / deceleration of the car based on the detection result of 2a,
The target value of the suspension rigidity with respect to the acceleration / deceleration of the automobile is set by using the map I for turning shown in FIG. 2 or 4 and the map II for straight running shown in FIG. 3 or 5. The hydraulic control amount setting unit 11b sets the control amount of each control valve 10a, 10b necessary to obtain this target value based on the target value of the suspension stiffness set by the suspension stiffness setting unit 11a.
A control signal corresponding to the control amount is sent to each control valve 10a, 1
It is output to 0b.

The maps shown in FIGS. 2 and 3 are FFs.
For cars, the maps shown in FIGS. 4 and 5 are for FR cars, and these maps will be described in detail later.
The suspension rigidity setting unit 11 sets a target value of suspension rigidity for each FF vehicle and FR vehicle so as to suppress a change in steer characteristic that occurs depending on the acceleration / deceleration.
It is stored in the memory unit (not shown) in a.

Further, in this embodiment, the control valve 10a,
When 10b is in the open state, the oil driven by the oil pump 14 is stored in the accumulator 18 after being appropriately regulated by the valves 16 and 17, and the control valve 10a or 10
b to supply / discharge ports 20a, 20b or supply / discharge ports 20c, 20
It is supplied into each oil chamber 7a, 7b or 8a, 8b of the actuator (suspension bush) 1 through d. The control valve 10a or 10b is provided in each oil chamber 7
When the inside of a, 7b or 8a, 8b reaches a predetermined pressure, it is closed, so that the pressure in each oil chamber 7a, 7b or 8a, 8b is kept constant at a predetermined magnitude. 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 is reduced. ing.

Therefore, the actuator 1 of this embodiment
Then, for example, by adjusting the internal pressure of the oil chambers 7a and 7b, the first
Is adjusted in the direction (in this example, the vehicle width direction, that is, the lateral direction), 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 and 8b. To be 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 force for restraining the inner end of the lower arm 24 of the suspension can be adjusted independently from the two directions (lateral direction and front-back direction), and the suspension rigidity can be adjusted two-dimensionally. You can do it. Since the restraining force between the suspension and the vehicle body 26 also works at other joints, the suspension rigidity adjusting direction when the supporting rigidity force of the inner end of the lower arm 24 is adjusted in the vehicle width direction or the vehicle length direction is as follows. However, 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 apparatus as one embodiment of the present invention is constructed as described above, the controller 11 follows the flow chart shown in FIG. 7 based on the information from the vehicle speed sensor 12a and the steering angle sensor 12b. By controlling the control valves 10a and 10b of the front and rear hydraulic control systems 10, the pressures in the oil chambers 7a, 7b, 8a and 8b of the front and rear actuators 1 are adjusted to adjust the front and rear suspension rigidity. Then, the wheel alignment of the automobile is adjusted so as to suppress the steer characteristic change caused by the acceleration / deceleration.

That is, in the apparatus of this embodiment, first, after initializing the controller 11 and making initial settings such as the setting of the maps I and II (step S1), the sensors such as the vehicle speed sensor 12a and the steering angle sensor 12b. The detected 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 of the steering 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 rigidity is set according to the acceleration / deceleration calculated in step S3, according to the map I shown in FIG. 2 or 4. (Step S
5). On the other hand, when it is determined in step S4 that the vehicle is not turning, that is, is traveling straight, the front and rear suspensions are determined according to the acceleration / deceleration calculated in step S3 according to the map II shown in FIG. 3 or FIG. The rigidity is set (step S6).

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

At this time, in the actuator 1 of the present embodiment, the rigidity can be adjusted independently in each of the lateral direction and the front-back direction of the automobile as described above, but in the present embodiment, the rigidity can be adjusted laterally. Both the direction and the front-back direction shall be performed simultaneously. That is, when the suspension rigidity is increased, the rigidity is increased in both directions, and when the suspension rigidity is decreased, the rigidity is decreased in both directions.

Further, when the suspension rigidity is changed 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.
Smoothly change the current value to the target value. That is,
When driving at high speed or when the steering angular velocity is high (when turning sharply)
Since it is considered necessary to change the suspension rigidity quickly, the time constant should be kept small.On the other hand, when the vehicle is traveling at low speed or the steering angular velocity is small, there is no problem even if the suspension rigidity is changed gently, and the time constant should be large. To do. In addition,
The setting of the time constant when changing the suspension rigidity is performed by changing the duty ratio of the control valves 10a and 10b or by providing a variable throttle valve for adjustment.

By the way, between the suspension rigidity and the cornering power, the steer amount (displacement amount) decreases as the suspension rigidity increases, and the increase in the tire equivalent cornering power decreases, while the steering amount decreases when the suspension rigidity decreases. Is increased, and the increase in tire equivalent cornering power is increased. Further, there is a relationship between the cornering power and the change in the steer characteristic, that is, when the cornering power of the front wheels is large, there is an oversteering tendency, while when the cornering power of the rear wheels is large, there is a tendency of understeering.

In the present embodiment, based on these relationships, basically, considering that the FF vehicle has the understeer tendency and the FR vehicle has the oversteer tendency, and the steer characteristic change according to the acceleration / deceleration, Target values of the front and rear suspension stiffness that can suppress the steer characteristic change (oversteer tendency, understeer tendency) that occurs according to the acceleration / deceleration are set as the maps shown in FIGS.

Then, as described above, in steps S5 and S6 in FIG. 7, the target values of the front and rear suspension rigidity are set based on these maps I and II, and the front and rear suspension rigidity is set to the target values. 1 and 6 are adjusted by the mechanisms shown in FIGS. In this embodiment, the front and rear suspension rigidity is adjusted separately, so in FIGS. 2 to 5, the front side suspension rigidity is denoted by a symbol F and shown by a solid line, while the rear side suspension rigidity is shown. Code R
Is attached and is shown by a broken line.

Further, when setting the map, basically, the control for lowering the tire equivalent cornering power of the rear wheels (that is, the control for increasing the suspension rigidity), which leads to lowering the limit performance, is not performed. Further, when going straight, it is basically to improve straight running stability by making toe-in, and as will be described later, toe-in is performed by longitudinal force steering by reducing suspension rigidity.

Each map will be described in detail below. Map I for setting a target value of suspension rigidity with respect to acceleration / deceleration during turning of an FF vehicle is given as shown in FIG. In an FF vehicle, as the acceleration increases during turning acceleration, the driving force of the front wheels (driving wheels) increases, the tire equivalent cornering power of the front wheels decreases, and the understeer tendency progresses.
As indicated by, the lower side suspension rigidity is compensated for by compensating for the decrease in the cornering power of the front wheels, and the understeer tendency is suppressed.

On the other hand, at the time of deceleration of turning of the FF vehicle (during braking), the braking force is applied to both the front wheels and the rear wheels, so that the tire equivalent cornering power is reduced for both the front wheels and the rear wheels. This decreasing tendency is larger in the front wheels that receive a larger braking force than in the rear wheels, and therefore, as shown by the symbols F and R in the left half of FIG. While significantly lowering the suspension rigidity, it compensates for the decrease in cornering power for both the front and rear wheels, suppressing the understeer tendency for the front wheels and suppressing the oversteer tendency for the rear wheels.

Map II for setting the target value of suspension rigidity with respect to acceleration / deceleration when the FF vehicle goes straight is
It is given as shown in FIG. In an FF vehicle, during straight-ahead acceleration, the tire equivalent cornering power of the front wheels decreases as the driving force of the front wheels, which are the drive wheels, decreases, the understeer tendency advances, the straight-ahead stability increases, and the straight-ahead state becomes a preferable tendency. However, if the acceleration is too high (during a sudden start)
As the understeer tendency is excessive, the front suspension corner rigidity is increased by slightly lowering the front side suspension rigidity, as shown by the reference symbol F in the right half of FIG. 3, to suppress the understeer tendency. is doing. Also, as the acceleration increases, the cornering power of the rear wheels decreases due to the force due to the rearward leaning,
As the oversteering tendency progresses, the symbol R is added to the right half of FIG.
As indicated by the symbol, the rear side rigidity of the suspension is reduced to compensate the cornering power of the rear wheels and suppress the oversteering tendency.

On the other hand, when the FF vehicle is decelerating straight ahead (during braking), the braking force is applied to both the front wheels and the rear wheels, so that the tire equivalent cornering power is reduced for both the front wheels and the rear wheels. For the front wheels, it is in a favorable condition because the understeer tendency advances and the straight running stability increases due to the decrease in the tire equivalent cornering power, but if the deceleration is too large (during sudden deceleration)
As the understeer tendency is too advanced, the front suspension corner rigidity is increased by slightly lowering the front suspension rigidity as indicated by the symbol F in the left half of FIG. 3 to suppress the understeer tendency. is doing. Further, as the deceleration increases, the rear wheels during straight-line deceleration tend to float and the oversteer tendency progresses. Therefore, as shown by the reference symbol R in the left half of FIG. 3, the rear suspension rigidity is increased. By lowering it, the cornering power of the rear wheels is supplemented and the oversteering tendency is suppressed.

A map I for setting a target value of suspension rigidity with respect to acceleration / deceleration when the FR vehicle is turning is given as shown in FIG. In FR vehicles, as the acceleration increases during turning acceleration, the driving force of the rear wheels (driving wheels) increases, the tire equivalent cornering power of the rear wheels decreases, and oversteering tends to proceed. As indicated by the reference sign F, the rear side rigidity of the suspension is reduced to compensate for the decrease in the cornering power of the rear wheels and suppress the oversteering tendency.

On the other hand, during turning deceleration of the FR vehicle (during braking), as in the case of the FF vehicle shown in FIG. 2, the braking force is applied to both the front wheels and the rear wheels, so that the tire equivalent cornering is applied to both the front wheels and the rear wheels. Power will be reduced. This decreasing tendency is larger in the front wheels that receive a larger braking force than in the rear wheels, and therefore, as shown by the reference symbols F and R in the left half of FIG. While significantly lowering the suspension rigidity, it compensates for the decrease in cornering power for both the front and rear wheels, suppressing the understeer tendency for the front wheels and suppressing the oversteer tendency for the rear wheels.

Map II for setting the target value of suspension rigidity with respect to acceleration / deceleration when the FR vehicle goes straight ahead is as follows:
It is given as shown in FIG. In an FR vehicle, the driving force of the rear wheels (driving wheels) increases as the acceleration increases during straight-ahead acceleration, the tire equivalent cornering power of the rear wheels decreases, and the oversteering tendency greatly advances.
As indicated by the reference character R in the right half of the above, the rear suspension rigidity is greatly reduced to compensate for the decrease in the cornering power of the rear wheels and suppress the oversteering tendency. Further, the front wheels during straight-ahead acceleration tend to float as the acceleration increases, and the oversteer tendency advances. Therefore, as shown by the reference symbol F in the right half of FIG. By increasing it, the cornering power of the front wheels is reduced and the oversteering tendency is suppressed.

On the other hand, when the FR vehicle is decelerating straight ahead (during braking), as in the case of the FF vehicle shown in FIG. 3, both the front wheels and the rear wheels receive the braking force, so that the tire equivalent cornering is applied to both the front wheels and the rear wheels. Power is reduced. Regarding the front wheels, the understeer tendency progresses due to the decrease in the tire equivalent cornering power, and the straight running stability increases, which is a preferable state.
If the deceleration is too large (during rapid deceleration), the understeer tendency will proceed too much. Therefore, as shown by the reference symbol F in the left half of FIG. It increases cornering power and suppresses the understeer tendency. Further, the rear wheel during straight-line deceleration becomes more floating as the deceleration increases, and the oversteer tendency progresses. Therefore, as shown by the symbol R in the left half of FIG. By lowering it, the cornering power of the rear wheels is supplemented and the oversteering tendency is suppressed.

As described above, according to the wheel alignment control apparatus of the present embodiment, the map I, shown in FIGS.
A target value of front and rear suspension rigidity is set by using II, and the front and rear actuators 1 are set based on the target value.
By adjusting the pressure in the oil chambers 7a, 7b, 8a, 8b in the hydraulic pressure control system 10 to suppress the change in steer characteristics (oversteer tendency, understeer tendency) that occurs according to the acceleration / deceleration, the suspension rigidity is controlled. Adjustment is performed and wheel alignment is adjusted. As a result, it is possible to realize optimum compliance steering when accelerating and decelerating during straight traveling and during turning while eliminating steer changes due to lateral force, longitudinal force, etc. during normal straight traveling, which can contribute to improvement of straight traveling and turning. There is.

In the above 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 detecting means such as a G sensor may be used. Further, 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. However, the actuator 1 operates in the lateral direction and the front-rear direction of the vehicle as described above. Since the rigidity can be adjusted independently for each, when adjusting the suspension rigidity when going straight, the longitudinal rigidity of the actuator 1 is adjusted to control the longitudinal force steer, while the suspension rigidity is adjusted when turning. In this case, the lateral rigidity of the actuator 1 may be adjusted to control the lateral force steer.

Further, in the above-described embodiment, the rigidity adjusting mechanism 1A for adjusting the suspension rigidity is used as the alignment adjusting means to perform the alignment adjustment based on the suspension rigidity. However, the mechanism for directly adjusting the wheel alignment is possible. May be used.

[0046]

As described in detail above, according to the wheel alignment control device of the present invention, the alignment adjusting means for adjusting the wheel alignment of the automobile and the acceleration state detecting means for detecting the acceleration state of the automobile are provided. The acceleration / deceleration is provided by a very simple configuration in which a control means for controlling the alignment adjusting means is provided so as to suppress a change in steer characteristic that occurs according to the acceleration state based on the acceleration state information from the acceleration state detecting means. The optimum compliance steer can be obtained according to the above, and the compliance steer control can be positively used during acceleration / deceleration while eliminating the steer change due to lateral force, longitudinal force, etc. during normal straight traveling, improving straightness and turning performance. There is an advantage to be able to do it.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of a map for setting a target value of suspension rigidity with respect to acceleration / deceleration during turning of an FF vehicle.

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 an FF vehicle travels straight.

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

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

FIG. 6 is a view showing a suspension bush with a rigidity adjusting mechanism which constitutes an alignment adjusting means in the present embodiment, and FIG. 6 (a) is a sectional view as seen from the axial direction of the rod;
(B) is a VIb-VIb arrow sectional view of (a), (c) is a VIc-VIc arrow sectional view of (a).

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

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

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

FIG. 12 is a side view of essential parts showing an example of mounting a suspension bush on a suspension in the present embodiment.

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

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

[Explanation of symbols]

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 part 11b Hydraulic control amount setting part 12 Sensor group 12a As acceleration state detection 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 Joint joint Cement 26 body 27 bush 28 spring 29 the upper arm

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takao Morita 5-3-8, Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation

Claims (1)

[Claims] 1. An alignment adjusting means capable of adjusting wheel alignment of an automobile, and an acceleration state detecting means for detecting an acceleration state of the automobile, wherein an acceleration state is set based on acceleration state information from the acceleration state detecting means. A wheel alignment control device, characterized in that a control means for controlling the alignment adjusting means is provided so as to suppress a change in steer characteristic that occurs.