JP2847942B2 - Suspension alignment control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension alignment control device suitable for use in an automobile suspension.

2. Description of the Related Art For vehicles such as automobiles, there have been developed ones in which the rigidity of a suspension can be adjusted according to, for example, a driver's preference.

As a mechanism for adjusting the rigidity of such a suspension, a mechanism that adjusts the roll rigidity by changing a mounting point of a stabilizer, or a mechanism that adjusts the rigidity of a suspension bush that elastically attaches a suspension to a vehicle body is used. There are types.

[Problems to be Solved by the Invention] By the way, when adjusting the rigidity of the suspension, there is a problem in which direction the rigidity is adjusted.

The rigidity of the suspension may be, for example, the rigidity in the vertical direction (vertical rigidity), the rigidity in the longitudinal direction (longitudinal rigidity), or the lateral rigidity (lateral rigidity) with respect to the vehicle body.

In particular, the longitudinal rigidity affects the riding comfort, and the degree of the influence varies depending on the vehicle speed. For example, as the vehicle speed increases, the strength of the longitudinal rigidity tends to adversely affect the riding comfort. However, at present, control corresponding to the vehicle speed is not performed, and it has not always been possible to secure a favorable ride comfort in a wide traveling speed range.

Therefore, it is conceivable that the higher the vehicle speed, the lower the front-rear stiffness and the better the riding comfort. In addition, the influence of the input longitudinal acceleration remains on the suspension for a long time and adversely affects the ride comfort, and further adversely affects the steering feeling. Therefore, in consideration of such a situation, it is desired to control the longitudinal rigidity of the suspension, which can improve the ride comfort in a wide traveling range.

Japanese Utility Model Publication No. 60-23203 discloses a technique in which the longitudinal rigidity of a suspension is controlled in accordance with the vehicle speed to reduce the flutter level at a specific vehicle speed.

Further, Japanese Patent Application Laid-Open No. Sho 60-219105 discloses a technique in which the front-rear stiffness of a suspension is controlled based on vehicle speed information and transmission information, thereby improving controllability and ride comfort. .

However, these publications have no description or suggestion about the case where the vehicle is subjected to longitudinal acceleration due to a protrusion on a road surface or the like, and the technology described in these publications cannot solve the above problems.

The present invention has been devised in view of such a problem, and by always adjusting the longitudinal rigidity according to the vehicle speed and the longitudinal acceleration of the vehicle, it is possible to obtain a good ride in a wide traveling speed range from low speed to high speed. It is an object of the present invention to provide a suspension alignment control device capable of ensuring comfort.

[Means for Solving the Problems] For this reason, a suspension alignment control device according to the present invention includes a suspension rigidity adjusting device capable of adjusting the longitudinal rigidity of a suspension provided in a vehicle, and a control device controlling the suspension rigidity adjusting device. A vehicle speed sensor for detecting a running speed of the vehicle, a straight traveling state detecting means for detecting a straight traveling state of the vehicle, and a longitudinal acceleration sensor for detecting a longitudinal acceleration of the vehicle. A vehicle speed corresponding control unit that outputs an operation control signal to the suspension rigidity adjusting means so as to weaken the longitudinal rigidity of the suspension as the vehicle speed increases based on information from the sensor; Based on the information, when the vehicle receives a longitudinal acceleration during straight running, the magnitude of the longitudinal acceleration increases. The suspension rigidity adjusting means is provided with a longitudinal acceleration addition control unit that outputs an operation control signal to the suspension rigidity adjusting means so as to temporarily increase the longitudinal rigidity of the suspension for a control time that increases according to the size. .

[Operation] In the suspension alignment control device of the present invention described above, the vehicle speed corresponding control unit of the control means causes the suspension rigidity adjusting means to reduce the longitudinal rigidity of the suspension as the vehicle speed increases, based on information from the vehicle speed sensor. An operation control signal is output. This makes it difficult for the longitudinal rigidity of the suspension to adversely affect the riding comfort during high-speed running.

When the vehicle receives longitudinal acceleration based on information from the straight traveling state detecting means and the longitudinal acceleration sensor when the vehicle receives a longitudinal acceleration due to overcoming a protrusion or the like during straight traveling, the control unit increases according to the magnitude of the longitudinal acceleration. An operation control signal is output to the suspension rigidity adjusting means so as to temporarily increase the longitudinal rigidity of the suspension for a control time. Therefore, even when the longitudinal rigidity of the suspension is reduced during high-speed running, the longitudinal rigidity of the suspension is temporarily increased when subjected to longitudinal acceleration such as over a projection, and the suspension is input to the suspension. A situation in which the influence of the longitudinal acceleration remains for a long time on the suspension and adversely affects the riding comfort and the steering feeling is avoided. In addition, such a reinforcement of the longitudinal rigidity of the suspension is performed only for a control time that increases in accordance with the magnitude of the longitudinal acceleration during straight running, so that there is no influence on steering, and the influence of overcoming a protrusion or the like is reduced. Later, since the longitudinal rigidity of the suspension quickly returns to the strength corresponding to the vehicle speed, it is possible to ensure a good ride quality thereafter.

[Embodiment] Hereinafter, a suspension alignment control device as an embodiment of the present invention will be described with reference to the drawings.
FIG. 2 is a block diagram showing this structure, FIG. 2 (a) is a sectional view of the suspension rigidity adjusting means viewed from the axial direction,
FIG. 2 (b) is a cross-sectional view taken along the line IIb-IIb in FIG. 2 (a),
FIG. 2 (c) is a sectional view taken along the line IIc-IIc in FIG. 2 (a),
FIG. 3 is a schematic view showing an example of mounting on the suspension in the vehicle length direction, FIG. 4 is a schematic plan view showing an example of mounting on the suspension, and FIG. 5 is an example of mounting on the suspension. FIG. 6 is a detailed view seen in the longitudinal direction, FIG. 6 is a plan view of a main part showing an example of mounting on the suspension, FIG. 7 is a side view of a main part showing an example of mounting on the suspension, and FIG. FIG. 9 is a graph showing a specific characteristic of rigidity by the control, FIG. 10 is a time chart showing a control operation at the time of external force addition, and FIG. 11 is a control time characteristic of the control at the time of external force addition. Graph showing the 12th and 13th
Each of the figures is a cross-sectional view showing another suspension rigidity adjusting means, and in each figure, the same reference numerals indicate similar members.

The configuration of this suspension alignment control device is as follows:
As shown in FIG. 1, a suspension bush 1 with a rigidity adjusting mechanism as suspension rigidity adjusting means, a controller 11 as control means for controlling the suspension rigidity adjusting means (suspension bush) 1,
A steering angle sensor 12b as a steering state sensor that can determine whether the vehicle is in a straight running state or a turning state, a vehicle speed sensor 12c that can detect the traveling speed of the vehicle, and detects a longitudinal acceleration acting on the vehicle speed A longitudinal acceleration sensor 12d is provided.

The suspension bush 1 with a rigidity adjusting mechanism is provided on a mounting portion of an automobile suspension to a vehicle body. For example, the suspension bush 1 whose operation is controlled by hydraulic pressure by a hydraulic control system 10 can adjust the rigidity of the suspension from two directions. 2 (a) to 2 (c) are conceivable. The suspension bush with the rigidity adjusting mechanism is also referred to as a rigidity adjusting actuator 1.

This suspension bush 1, as shown in the figure,
The case 2 includes a case 2 attached to the vehicle body, a shaft 3 attached to the suspension side, and rubber bodies 4 and 6 as elastic support members for elastically supporting the shaft 3 in the case 2.

Among them, the rubber body 4 is provided such that both ends thereof are fixed to the inner wall of the case 2 at an intermediate portion in the first direction [the vertical direction in FIG. Spaces 7a and 7b as first oil chambers are formed on both sides of 4. Thus, the rubber body 4 elastically supports the shaft 3 inside the rubber body 4 in the first direction.

The rubber body 6 has both ends fixed to the inner wall of the case 5 at an intermediate portion in the second direction [the left-right direction in FIG. 2A] in the inner case 5 built in the rubber body 4. Spaces 8a and 8b as second oil chambers are formed on both sides of the rubber body 6. Thereby, the rubber body 6
Supports the shaft 3 therein elastically in the second direction.

Then, the support rigidity in the first direction changes according to the oil pressure supplied into the oil chambers 7a and 7b, and the support rigidity in the second direction changes according to the oil pressure supplied into the oil chambers 8a and 8b. The support stiffness changes.

Reference numeral 9 denotes a reinforcing member incorporated in each of the rubber members 4, 6, and the reinforcing members 9 make the rubber members 4, 6 have a certain tension (rigidity). Reference numerals 20a to 20d denote hydraulic supply / discharge ports for the oil chambers 7a, 7b, 8a, 8b.

The first and second oil chambers 7a, 7b, 8a, 8b are connected to a hydraulic control system 10 for controlling the oil pressure inside the oil chambers 7a, 7b, 8a, 8b, These oil chambers 7a, 7b, 8
A stiffness adjusting mechanism 1A for adjusting the suspension stiffness is composed of the a, 8b and the hydraulic control system 10.

In this example, the first direction [vertical direction in FIG. 2 (a)] is the front-rear direction of the vehicle body, and the second direction [lateral direction in FIG. 2 (a)] is the lateral direction of the vehicle body. It is installed so that it becomes.

The hydraulic control system 10 is configured as shown in the upper part of FIG. 1. In FIG. 1, 10a and 10b are control valves connected to supply / discharge ports 20a to 20d, and 11 is a control valve 10a and 10b. Controller for outputting control signals, 12 is a sensor group such as a vehicle speed sensor 12c connected to the controller 11, 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, 19 Is an oil reservoir.

Among the control valves 10a and 10b, the control valve 10a is a longitudinal rigidity control valve, and is connected to oil chambers 7a and 7b arranged in the longitudinal direction of the vehicle body so as to adjust the longitudinal rigidity. The control valve 10b is a lateral rigidity control valve, and is connected to oil chambers 8a and 8b arranged side by side in the lateral direction of the vehicle body so that the lateral rigidity can be adjusted.

These control valves 10a, 10b are connected to the oil chambers 7a, 7b, 8
a, an open state communicating between the inside of 8b and the accumulator 18 side,
The closed state of closing the supply / drain ports 20a, 20b, 20c, 20 of the oil chambers 7a, 7b, 8a, 8b, and the oil chambers 7a, 7b, 8a, 8b from the supply / drain ports 20a, 20b, 20c, 20
It is configured to be able to take a drain state in which the hydraulic pressure in the inside is discharged.

Therefore, if the control valves 10a and 10b are 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 is supplied from the control valve 10a or 10b to the supply / drain opening 20a, 20b or the supply / drain opening 20c, 20d.
Through the actuator (suspension bush)
It is supplied into each of the oil chambers 7a, 7b or 8a, 8b. Then, the control valve 10a or 10b is closed when the inside of each oil chamber 7a, 7b or 8a, 8b reaches a predetermined pressure, whereby the oil chamber 7a, 7b or 8 is closed.
The pressure in a, 8b is kept constant 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.

The controller 11 controls the control valves 10a and 10b to one of the above-described states. The controller 11 controls the control valve 10a based on information from various sensors (sensor groups) 12 to control the suspension. Although the longitudinal rigidity is adjusted, in particular, the control valve 10a is controlled in accordance with the vehicle speed during straight running based on information from the steering angle sensor 12b and the vehicle speed sensor 12c as straight running state detecting means for detecting the straight running state of the vehicle. Vehicle speed control unit 11b and steering angle sensor
Based on information from the longitudinal acceleration sensor 12d and the longitudinal acceleration sensor 12d, a longitudinal acceleration addition control unit 11c for temporarily adjusting the longitudinal rigidity of the suspension when the vehicle receives longitudinal acceleration from road surface reaction force or the like during straight running is provided. ing.

In addition, although not shown, the controller 11 is also provided with a control unit that controls the control valves 10a and 10b according to, for example, a braking state or the like to adjust the longitudinal rigidity.

The vehicle speed control unit 11b controls the longitudinal rigidity of the suspension based on the information from the vehicle speed sensor 12c so that the characteristics shown in FIG. 9 are obtained. That is, the longitudinal rigidity of the suspension corresponding to the detected vehicle speed V is set,
A control signal is sent to the front / rear rigidity control valve 10a so as to obtain this rigidity.

Therefore, up to a certain high-speed vehicle speed, the front-rear stiffness of the suspension is set to decrease as the vehicle speed increases, and the stiffness is set to a small value when the vehicle speed reaches a certain high-speed vehicle speed.

Further, when the longitudinal acceleration addition control unit 11c receives longitudinal acceleration as shown in FIG. 10 (a) due to a road surface reaction force or the like, the longitudinal rigidity of the suspension is temporarily reduced in FIG. 10 (b). Adjust higher (harder) as shown. This is because, at high speeds, the longitudinal rigidity of the suspension is reduced by the vehicle speed corresponding control unit 11b. Therefore, when the vehicle is subjected to longitudinal acceleration due to a projection on the road surface, the effect of the inputted longitudinal acceleration remains on the suspension for a long time. It has an adverse effect on ride comfort and handling feeling. Therefore, when a longitudinal acceleration is received, the longitudinal rigidity of the suspension is temporarily hardened for a control time Ts (see FIG. 11) that increases according to the magnitude of the longitudinal acceleration, so that the convergence is improved. is there.

However, the vehicle speed corresponding control and the control at the time of adding the longitudinal acceleration are set so as to be performed only when the vehicle is traveling straight ahead based on the information from the steering angle sensor 12b. This is to minimize the change in compliance at the time of turning so that a sense of incongruity does not occur at the time of steering.

Therefore, during turning, the longitudinal rigidity of the suspension is maintained at a constant value having a certain magnitude. After the turning is completed, the above-described vehicle speed control and longitudinal acceleration addition control are performed.

Suspension bush 1 with rigidity adjustment mechanism described above
Can be installed on various types of suspension.For example, when installed on a strut type suspension, as shown in FIGS. 3 and 4, between the inner ends of the front and rear lower arms 24 and the vehicle body 26, The shaft 3 can be installed with the vertical direction. Here, the installation direction of the actuator 1 is set such that the shaft 3 is oriented in the vertical direction as described above.
(Vertical direction in FIG. 2 (a)) is directed toward the vehicle length direction, and the second direction [left / right direction in FIG. 2 (a)] is directed toward the vehicle width direction.

In the drawing, 21 is a wheel, 22 is a strut, 27 is a rubber bush that rotatably supports the inner end of the strut 22 around a vehicle length direction axis, 25 is a bush 27 and a shaft 3 of the actuator 1.
And a connection joint for connecting

More specifically, it is configured as shown in FIGS. In the drawings, the same reference numerals as those in FIGS. 3 and 4 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.

Since the suspension alignment control device as one embodiment of the present invention is configured as described above, the suspension bush 1 with the stiffness adjusting function is controlled by the controller 11 from the sensors 12 such as the brake sensor 12a and the steering angle sensor 12b. Based on the information, the control valves 10a, 10b
Control.

That is, as shown in FIG. 8, control is started in conjunction with turning on the ignition or the like. First, each control parameter is set to an initial value (step S1), and the vehicle speed sensor 12c
(Data) from the sensors 12 such as the steering angle sensor 12b and the like
Is read (step S2).

Then, in step S3, it is determined whether or not the steering angle θ is substantially 0 based on the information from the steering angle sensor 12b.

When the steering angle θ is not substantially zero, that is, at the time of turning, the longitudinal rigidity of the suspension is set to a constant value having a certain magnitude, but when the steering angle θ is substantially zero,
That is, during straight running, the longitudinal rigidity of the suspension is controlled.

That is, in step S4, a longitudinal stiffness value corresponding to the vehicle speed V is obtained based on the information from the vehicle speed sensor 12a as shown in FIG. Then, followed by step S5, based on the information from the longitudinal acceleration sensor 12d, the magnitude of the longitudinal acceleration exerted on the vehicle body (| longitudinal G |) is to determine whether greater than the threshold value G _1. As the threshold value G _1, the longitudinal acceleration exerted on the vehicle body due upthrust force applied from road surface irregularities and the like, appropriate values may be a boundary value that is to affect the ride comfort and the like are set.

When running on a flat road, | longitudinal G | usually threshold G ₁
First, the process proceeds to step S14, but here, since the timer has not been started, the process proceeds from step S14 to step S6, and the actuator 1 is moved so that the longitudinal rigidity obtained in step S4 is obtained. A drive command is issued to the drive unit of the control valve 10a.

That is, an operation control signal corresponding to the set rigidity is sent from the controller 11 to the control valve 10a so that the set rigidity is obtained, and the front-back rigidity is adjusted by adjusting the hydraulic pressure.

Thus, the front-rear rigidity of the suspension decreases as the vehicle speed increases until the suspension reaches a certain high-speed vehicle speed, and takes a small constant value when the suspension reaches a certain high-speed vehicle speed.

Therefore, even if the vehicle speed increases, a soft and good ride quality can be ensured.

Also, if you receive a pushing force from the unevenness of the road surface,
If this is a certain degree or more dimensions, | longitudinal G | is threshold G ₁
Then, the process proceeds from step S5 to step S7. First, a control time Ts is set according to the magnitude of the longitudinal acceleration detected by the longitudinal acceleration sensor 12d using the map shown in FIG.

Then, in step S8, it is determined whether or not the control time Ts is larger than the previously obtained Ts'. If Ts is larger than Ts', in step S9, Ts is newly set to Ts', and Ts is set to Ts.
If it is not larger than s ', Ts' is not updated, and in any case, the process proceeds to step S10. By the control from step S8 to step S10, a control time Ts' corresponding to the maximum value of the longitudinal acceleration applied to the vehicle body is obtained.

In step S10, it is determined whether or not the count of the timer value T has started. If the count of the timer T has not started, the timer T is started in step s11.

Then, in step S12, it is determined whether or not the timer value T is greater than the control time Ts'. Until the timer value T becomes greater than the control time Ts', that is, the control time Ts' During the period, the front and rear rigidity is high (that is,
Adjust hard). Incidentally, after the timer T started | longitudinal G | When falls below the normal threshold G _1, the process proceeds from step S5 to step S14, in this case, since the process proceeds from step S14 to step S12, during the control time Ts' is Adjust the front and rear rigidity high.

As a result, when the longitudinal acceleration is received as shown in FIG. 10 (a), the stiffness of the suspension is changed to the set time Ts' from the stage where the longitudinal acceleration becomes a predetermined value or more, as shown in FIG. 10 (b). Only adjusted hard.

Therefore, the influence of the longitudinal acceleration quickly converges,
The adverse effect on the riding comfort and the steering feeling due to external force is suppressed.

In addition to the above-described control, the controller 11 performs suspension rigidity adjustment including lateral rigidity, such as adjustment according to a braking state.

During turning, the longitudinal rigidity of the suspension may be fixed to the size at the start of turning.

In addition, the installation posture of the suspension bush 1 is not limited to that of the above-described embodiment. For example, the suspension bush 1 may be installed with the first direction facing the vehicle width direction and the second direction facing the vehicle length direction.

Further, the present suspension alignment control device includes:
It may be one that can control the stiffness in the direction, and it can be applied sufficiently using other types of suspension stiffness control means,
Furthermore, it can be applied to other types of suspensions.

For example, a suspension rigidity control means as shown in FIGS.

That is, as shown in FIGS. 12 and 13, each has a structure in which the suspension-side shafts 43 and 53 are elastically supported through the elastic members 44 and 54 in the vehicle body-side cases 42 and 52, respectively. 54
Oil chambers 45a, 45b, 53a and 53b are provided on both sides of the oil chamber, respectively, and the rigidity in each direction (all in the horizontal direction in the drawing) can be adjusted by adjusting the oil pressure in the oil chamber. If the direction in which the rigidity can be adjusted is installed in the front-rear direction of the vehicle body, the present invention can be applied.

Also, the control performed by the control means (controller) 11 may be various controls other than the above-described vehicle speed control, the control at the time of adding longitudinal acceleration, and the control at the time of braking.

[Effects of the Invention] As described above in detail, according to the suspension alignment control device of the present invention, a suspension rigidity adjusting means capable of adjusting the longitudinal rigidity of a suspension provided in a vehicle, and the suspension rigidity adjusting means are controlled. A control means, a vehicle speed sensor for detecting a running speed of the vehicle, a straight traveling state detecting means for detecting a straight traveling state of the vehicle, and a longitudinal acceleration sensor for detecting a longitudinal acceleration of the vehicle; A vehicle speed corresponding control unit for outputting an operation control signal to the suspension rigidity adjusting means so as to decrease the longitudinal rigidity of the suspension as the vehicle speed increases based on information from the vehicle speed sensor, the straight traveling state detecting means, and the longitudinal acceleration sensor Based on information from
When the vehicle receives a longitudinal acceleration during straight running, before and after outputting an operation control signal to the suspension rigidity adjusting means so as to temporarily increase the longitudinal rigidity of the suspension for a control time that increases according to the magnitude of the longitudinal acceleration. With the simple configuration of adding a control unit at the time of acceleration addition, the front-rear rigidity is adjusted according to the vehicle speed, so that a good ride comfort can always be secured over a wide running speed range from low speed to high speed. In addition, when the vehicle is subjected to longitudinal acceleration such as over a bump during high-speed driving, the longitudinal rigidity of the suspension is temporarily increased, so the convergence of the suspension is increased and the longitudinal acceleration The influence is quickly eliminated, and the riding comfort and the steering feeling can be maintained satisfactorily. Further, since the reinforcement in the front-rear direction of the suspension is performed during straight running, the suspension is not performed during steering, so that there is no sense of incongruity during steering. Further, since the control is performed only for the control time that increases according to the magnitude of the longitudinal acceleration, after the influence of overcoming a protrusion or the like is reduced, the longitudinal rigidity of the suspension is quickly returned to the strength according to the vehicle speed, and thereafter, The ride comfort can be improved.

[Brief description of the drawings]

FIGS. 1 to 13 show a suspension alignment control apparatus according to an embodiment of the present invention. FIG. 1 is a block diagram showing the configuration thereof, and FIG. 2 (a) shows the suspension rigidity adjusting means in the axial direction. Sectional view seen from above, FIG. 2 (b)
Is a cross-sectional view taken along the line IIb-IIb in FIG. 2 (a), and FIG. 2 (c).
Is a cross-sectional view taken along the line IIc-IIc in FIG. 2 (a), FIG. 3 is a schematic view showing an example of mounting on the suspension in a vehicle length direction, and FIG. 4 is an example of mounting on the suspension. FIG. 5 is a detailed view showing an example of attachment to the suspension in the vehicle length direction, FIG. 6 is a plan view of a main part showing an example of attachment to the suspension, and FIG. 7 is a suspension of the suspension. FIG. 8 is a flowchart showing the control operation, FIG. 9 is a graph showing the rigidity setting characteristics by the control, and FIG. 10 is a time showing the control operation when external force is applied. FIG. 11 is a chart showing the characteristics of the control time of the control when the external force is applied, and FIGS. 12 and 13 are sectional views showing other suspension rigidity adjusting means. 1 ... suspension rigidity adjusting means (suspension bush with rigidity adjusting mechanism or actuator for rigidity adjusting), 1A ... rigidity adjusting mechanism, 2 ... case, 3 ... axis,
4, 6 ... rubber body as elastic support member, 5 ... inner case, 7a, 7b ... space as first oil chamber, 8a, 8b ... second
9 as an oil chamber, 9 as a reinforcing member, 10 as a hydraulic control system, 10a as a longitudinal rigidity control valve, 10b as a lateral rigidity control valve, 11 as a controller as a control means, 11b as an actuator.
Vehicle speed control unit, 11c: Control unit for adding longitudinal acceleration, 12
……………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………… Have a great deal,
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
…… wheels, 21a …… knuckles, 22 …… struts, 23…
... Joint, 24 ... Lower arm, 25 ... Joint joint, 26 ... Body, 27 ... Bush, 28 ... Spring,
42,52 ... Case, 44, 54 ... Elastic member, 45a, 45b, 53a, 53
b ... Oil chamber.

Continuation of front page (72) Inventor Takao Morita 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (56) References JP-A-60-219105 (JP, A) JP-A-63- 22712 (JP, A) JP-A-2-193703 (JP, A) Japanese Patent Publication No. 8-5299 (JP, B2) Jiko 60-23203 (JP, Y2)

Claims (1)

(57) [Claims] 1. A vehicle speed sensor for detecting a running speed of a vehicle, comprising: a suspension rigidity adjusting means for adjusting a longitudinal rigidity of a suspension provided in a vehicle; and a control means for controlling the suspension rigidity adjusting means. The vehicle includes a straight traveling state detecting means for detecting a straight traveling state of the vehicle, and a longitudinal acceleration sensor for detecting a longitudinal acceleration of the vehicle. The control means increases the longitudinal rigidity of the suspension as the vehicle speed increases based on information from the vehicle speed sensor. When the vehicle receives longitudinal acceleration during straight running based on information from the vehicle speed corresponding control unit that outputs an operation control signal to the suspension stiffness adjusting means so as to weaken, and information from the straight running state detecting means and the longitudinal acceleration sensor. Temporarily increase the longitudinal rigidity of the suspension for the control time that increases according to the magnitude of the longitudinal acceleration. Characterized in that it includes a longitudinal acceleration subscription time control unit which outputs an operation control signal to the suspension rigidity adjusting means so that the suspension alignment controller.