JPH04146807A - Suspension alignment controller - Google Patents

Abstract

PURPOSE:To improve riding quality and turning property while. securing brake stability by providing a control section to cope with braking for operation control signals to a suspension rigidity control means so as to improve the longitudinal direction rigidity of the suspension when braking is applied. CONSTITUTION:A suspension bushing 1 with rigidity control mechanism controls control valves 10a and 10b based on the information from the sensor 12 such as a brake sensor 12a and steering angle sensor 12b by means of a controller 11. The control valve 10a controls longitudinal direction rigidity, and the control valve 10b controls cross direction rigidity. The control section 11a of a controller 11 for coping with braking outputs operation control signals to improve the longitudinal direction rigidity and cross direction rigidity of a suspension if a vehicle is running straight when braking is applied and outputs signals to improves only the longitudinal direction rigidity of the suspension if the vehicle is turning when braking is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension alignment control device suitable for use in automobile suspensions.

[Prior Art] Vehicles such as automobiles have been developed in which the rigidity of the suspension can be adjusted according to the driver's preference, for example.

Mechanisms for adjusting the rigidity of such suspensions include those that adjust the roll rigidity by changing the mounting points of the stabilizer, and those that adjust the rigidity of the suspension bushings that elastically attach the suspension to the vehicle body. There are some types that do.

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

The stiffness of the suspension includes, for example, the stiffness in the vertical direction with respect to the vehicle body (vertical stiffness), the stiffness in the longitudinal direction (front-rear stiffness), and the stiffness in the lateral direction (lateral stiffness).

When considering ride comfort and turning performance, it is easy to think that vertical stiffness is the main influence, but longitudinal stiffness and lateral stiffness also have a large effect. In other words, for ride comfort, turning performance, etc., the smaller the longitudinal stiffness, the better. In addition, a smaller lateral stiffness is generally advantageous for obtaining lateral caster and lateral force camber.

However, when considering braking stability, it is better for both the longitudinal and lateral stiffness of the suspension to be large to some extent.

The present invention was devised in view of such problems, and
An object of the present invention is to provide a suspension alignment control device that can improve riding comfort and turning performance while ensuring braking stability.

[Means for Solving the Problems] Therefore, the suspension alignment control device according to the first aspect of the present invention includes a suspension stiffness GU means capable of adjusting the longitudinal stiffness of a suspension provided in a vehicle, and a suspension stiffness adjustment means. and a control means for controlling the same.

A brake sensor capable of detecting an operating state of a brake provided on the vehicle is provided, and the control means controls the suspension stiffness adjustment means to increase the longitudinal stiffness of the suspension when the brake is applied based on information from the brake sensor. It is characterized by having a brake compatible control section that can output an operation control signal.

The suspension alignment control device according to the second aspect of the present invention further includes a suspension stiffness adjusting means capable of adjusting longitudinal stiffness and lateral stiffness of a suspension provided in a vehicle, and a control means controlling the suspension stiffness adjusting means. and a brake sensor for detecting the operating state of the brakes provided on the vehicle, and a steering state sensor for determining whether the vehicle is in a straight-ahead state or in a turning state, and the control means Based on the information from the brake sensor and the steering state sensor, an operation control signal is output to the suspension stiffness adjusting means to operate the brake so that the longitudinal stiffness and lateral stiffness of the suspension are high when the vehicle is moving straight when the brake is applied. The present invention is characterized in that it includes a brake corresponding control section that can output an operation control signal to the suspension stiffness adjusting means so that only the longitudinal stiffness of the suspension becomes high when the vehicle is in a turning state.

[Function] In the suspension alignment control device according to the first aspect of the present invention, the brake corresponding control section of the control means causes the suspension stiffness adjustment means to adjust the longitudinal stiffness of the suspension when the brake is applied based on information from the brake sensor. Outputs an operation control signal to increase the As a result, when braking, the front and rear stiffness of the suspension is increased and braking stability is ensured.When not braking, the front and rear stiffness of the suspension is set to a small value, thereby ensuring braking stability. Riding comfort and turning performance can be improved.

In the suspension alignment control device according to the second aspect of the present invention, the brake corresponding control section of the control means determines the suspension stiffness when the vehicle is traveling straight when the brake is applied, based on information from the brake sensor and the steering state sensor. An operation control signal is output to the adjustment means so that the front and rear stiffness and lateral stiffness of the suspension are increased, and when the vehicle is in a turning state when the brake is applied, the operation control signal is output to the suspension stiffness adjustment means so that only the front and rear stiffness of the suspension is increased. Output a signal. This means that if the brakes are activated while the vehicle is driving straight ahead.

The front and rear stiffness and lateral stiffness of the suspension are both increased to ensure braking stability, and while the vehicle is turning, the front and rear stiffness of the suspension is increased, but the lateral stiffness can be reduced, making it possible to brake while ensuring turning performance. Stability can be ensured. Therefore, like the device of the first claim above,
By setting the longitudinal and lateral stiffness of the suspension to be small when braking is not being performed, ride comfort and turning performance can be improved while ensuring braking stability.

[Embodiment] Below, a suspension alignment control device as an embodiment of the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram showing its configuration, and FIG. 2(b) is a cross-sectional view taken from the nb-nb arrow in FIG. 2(a), and FIG. 2(c) is a cross-sectional view taken from the l1c-]Ic arrow in FIG. 2(a). Figure 3 is a schematic diagram showing an example of how the suspension is installed when viewed from the longitudinal direction of the vehicle, Figure 4 is a schematic plan view showing an example of how the suspension is installed, and Figure 5 is an example of how the suspension is installed. 6 is a plan view of the main part showing an example of how it is installed on the suspension, FIG. 7 is a side view of the main part showing an example of how it is installed on the suspension, and FIG. 8 is a side view of the main part showing an example of how it is installed on the suspension. FIG. 9 is a flowchart showing the control operation, FIG. 9 is a graph showing the stiffness setting characteristics by the control, and FIG. 10 is a flowchart showing the control operation of a modification thereof. In each figure, the same reference numerals indicate the same members.

As shown in FIG. 1, the configuration of this suspension alignment control device includes a suspension bushing l with a stiffness adjustment mechanism as a suspension stiffness adjustment means, and a control means for controlling the suspension stiffness adjustment means (suspension bushing) l. a controller 11,
The vehicle is equipped with a brake sensor 12a that can detect the operating state of a brake provided on the vehicle, and a steering angle sensor 12b as a steering state sensor that can determine whether the vehicle is traveling straight or turning. In addition, brake sensor 1
2a outputs a brake activation signal when the brake is activated;
It also outputs a signal according to the amount of brake depression.

The suspension bushing 1 with a rigidity adjustment mechanism is capable of adjusting the longitudinal stiffness and lateral stiffness of the suspension, and its operation is hydraulically controlled by a hydraulic control system 10 9
This suspension bushing with a rigidity adjustment mechanism will also be referred to as a rigidity adjustment actuator 1.

This suspension bushing 1 with a rigidity adjustment mechanism is installed at the attachment point of the suspension of an automobile to the vehicle body, and as shown in FIGS. 2(a) to (c), a case 2 attached to the vehicle body side, It includes a shaft 3 attached to the suspension side and rubber bodies 4 and 6 as elastic support members that elastically support the shaft 3 within the case 2.

Of these, the rubber body 4 is located in the first direction [second direction] inside the case 2.
In the middle part in the vertical direction in Figure (a), both ends are fixed to the inner wall of the case 2, and spaces 7a and 7b as first oil chambers are formed on both sides of the rubber body 4. ing. Thereby, the rubber body 4 elastically supports the shaft 3 therein in the first direction.

Further, the rubber body 6 has both ends fixed to the inner wall of the case 5 in the second direction [in the middle of the left-right direction in FIG. Spaces 8a and 8b serving as second oil chambers are formed on both sides of the rubber body 6. Thereby, the rubber body 6 elastically supports the shaft 3 therein in the second direction.

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

Note that reference numeral 9 is a reinforcing material built into each of the rubber bodies 4 and 6, and this reinforcing material 9 ensures that the rubber bodies 4 and 6 have a certain tension (rigidity). Also, 20a-2
0d indicates each oil chamber 7a, 7b.

This is a supply/discharge port for hydraulic pressure to 8a and 8b.

These first and second oil chambers 7a, 7b, 8a
, 8b have these oil chambers 7a, 7b.

A hydraulic control system 10 that controls the internal hydraulic pressure of the oil chambers 8a and 8b is connected to these oil chambers 7a and 7b.

8a, 8b and the hydraulic control system 10 constitute a rigidity adjustment mechanism IA that adjusts suspension rigidity.

In this example, the first direction [vertical direction C in Fig. 2 (a) is the longitudinal direction of the vehicle body, and the second direction [Fig.
a) The direction of the lateral force in the vehicle body is installed so that the direction of the lateral force is in the lateral direction of the vehicle body.

The hydraulic control system 10 is configured as shown in the upper part of FIG. 1, and in FIG.
control valves connected to a to 20d; 11 is a controller that outputs control signals to the control valves 10a and 10b;
2 is a brake sensor 12 connected to the controller 11
13 is an orifice, 14 is an oil pump, 15.18 is an accumulator, 16 is a relief valve, 17 is a one-way valve, and 19 is an oil reservoir.

Among the control valves 10a and 10b, the control valve 10a is a longitudinal rigidity control valve, and has oil chambers 7a and 7 arranged in parallel in the longitudinal direction of the vehicle body so as to adjust the longitudinal rigidity.
connected to b. Further, 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 as to be able to adjust the lateral rigidity.

These control valves 10a and 10b are connected to the oil chamber 7.
an open state where the insides of a, 7b, 8a, 8b communicate with the accumulator 18 side, and oil chambers 7a, 7b.

A closed state in which the supply/discharge ports 20a, 20b, 20c, 20 of 8a, 8b are closed, and the supply/discharge ports 20a, 20b.

The oil pressure chambers 20c and 20 are configured to be in a drain state in which the oil pressure in the oil chambers 7a, 7b, 8a, and 8b is discharged.

Therefore, when the control valves 10a and 10b are in the open state, the oil pumped by the oil pump 14 is transferred to the valve 1.
6.17, the pressure is appropriately regulated and stored in the accumulator 18, and the control valve 10a or 10b is connected to the supply/discharge port 20a.
, 20b or through the supply/discharge ports 20c, 20d, the oil chambers 7a, 7 of the actuator (suspension bushing) 1
b or 8a, 8b. The control valve 10a or 10b is connected to each oil chamber 7a, 7b or 8a.

When the inside of 8b reaches a predetermined pressure, it is closed, thereby keeping the pressure inside each oil chamber 7a, 7b or 8a, 8b constant at a predetermined level. Further, when the control valve 10a or 10b is set to the drain state, the oil chamber 7
The oil in a, 7b or 8a, 8b is drained and the oil chamber 7
a, 7b or 8a.

The pressure inside 8b is reduced.

The controller 11 controls the control valves 10a and 10b to one of the above-mentioned states, and the controller 11 controls the control valve 10a and 10b based on information from various sensors (sensor group) 12.

A brake corresponding control section 11a is provided to control the brake control section 10b.

The brake corresponding control unit 11a controls the operation of the actuator 1 to increase the rigidity of the suspension when the brake is in operation, based on information from the brake sensor 12a and the steering angle sensor 12b.
When the brakes are applied, stiffness control differs depending on whether the vehicle is traveling straight or turning. In other words, when the vehicle is moving straight when the brakes are applied, an operation control signal is output that increases both the longitudinal and lateral stiffness of the suspension, and when the vehicle is turning when the brakes are applied, only the longitudinal stiffness of the suspension is increased. The operation control signal is output so that the

During normal times (when not braking), both the longitudinal and lateral stiffness of the suspension are set to be small.

The above-mentioned suspension bushing 1 with a rigidity adjustment mechanism is
It can be installed on various types of suspensions, but 1. For example, when installing on a strut type suspension,
As shown in FIGS. 3 and 4, the shaft 3 can be installed vertically between the inner ends of the front and rear lower arms 24 and the vehicle body 26. Here, actuator 1! !
In the force direction, the shaft 3 is installed vertically as described above, and the first direction [the vertical direction in Fig. 2 (a) is in the vehicle length direction]
The second direction [the left-right direction C in FIG. 2(a) is installed facing the vehicle width direction.

In the figure, 21 is a wheel, 22 is a strut, 27 is a rubber bushing that rotatably supports the inner end of the strut 22 around an axis in the longitudinal direction of the vehicle, and 25 is a joining joint that connects the bushing 27 and the shaft 3 of the actuator 1. It is.

Further, in detail, it is configured as shown in FIGS. 5 to 7. In the figure, the same reference numerals as those in FIGS. 3 and 4 indicate the same parts, 21a is a knuckle, 23 is a joint between the knuckle 21a and the outer end of the lower arm 24, and 28 is a spring.

Since the suspension alignment control device as an embodiment of the present invention is configured as described above, the suspension bushing 1 with a rigidity adjustment mechanism is controlled by the controller 11 to control the brake sensor 12a and the steering angle sensor 1.
Control valves 10a and 10b are controlled based on information from sensors 12 such as 2b.

That is, as shown in FIG. 8, control is started in conjunction with turning on the ignition, etc. First, each control parameter etc. is set to an initial value (step S1), and the brake sensor 12a, steering angle sensor 12b, etc. The information (data) from the sensor 12 is read (step S2).

Then, in step S3, it is determined whether a brake signal is being sent based on the information from the brake sensor 12a. If the brake signal is not being sent, the process proceeds to step S9, and the suspension stiffness (front and rear stiffness and lateral stiffness) ) is left in its initial state, that is, both the front and rear stiffness and the lateral stiffness of the suspension are made small. However, if a brake signal is being sent, the process proceeds to step S4, and the suspension is turned while turning based on the information from the steering angle sensor 12b. Determine whether there is.

If the vehicle is turning, the process advances to step S5 to set the longitudinal stiffness of the suspension. As shown in FIG. 9, this setting is made in accordance with the magnitude of the amount of brake depression sent from the brake sensor 12a so that the greater the amount of brake depression, the greater the rigidity. At this time, the lateral stiffness of the suspension is maintained at its initial small state.

If the vehicle is not turning, it means that the vehicle is traveling straight ahead, and the process proceeds to step S7, where the longitudinal stiffness and lateral stiffness of the suspension are set. The settings of this longitudinal stiffness and lateral stiffness are also
As shown in the figure, the rigidity is set to increase as the amount of brake depression increases.

In this way, after the longitudinal stiffness and lateral stiffness are set in step S5 or S7, the longitudinal stiffness is adjusted (step S6) and the lateral stiffness is adjusted (step S
8).

In other words, in order to obtain the set stiffness, an operation control signal is sent from the controller 11 to each control valve 10a, 10b according to the set stiffness, and the longitudinal stiffness is adjusted by the oil chamber 7.
By adjusting the hydraulic pressure in a and 7b.

The lateral rigidity is adjusted by adjusting the hydraulic pressure in the oil chambers 8a and 8b, respectively.

As a result, when the vehicle is traveling straight when the brakes are applied, an operation control signal is output to the suspension bushing (controller) 1 so that the longitudinal and lateral rigidities of the suspension are at predetermined heights, and each control valve 10a, 1
0b is opened only for a predetermined period, and the oil chambers 7a and 7b are opened.
By adjusting the hydraulic pressures 8a and 8b to predetermined heights, the suspension bushing 1 increases both the longitudinal and lateral rigidities of the suspension to predetermined levels.

Also, when the vehicle is turning when the brakes are applied,
An operation control signal is output to the suspension bushing (controller) 1 so that only the front and rear rigidity of the suspension is increased, and only the control valve 10a is opened.
By adjusting the oil pressure in the oil chambers 7a and 7b to a predetermined height, only the longitudinal rigidity of the suspension can be increased.

Therefore, when the vehicle is running straight and the vehicle is not braking, the front and rear stiffness and lateral stiffness of the suspension are set appropriately small to provide good ride comfort, and when braking, the front and rear stiffness of the suspension is significantly increased. This ensures braking stability. In addition, when the vehicle is running in a turning state and normal braking is not performed, the front and rear stiffness and lateral stiffness of the suspension are set appropriately small, as described above, to provide good ride comfort. Although the rigidity is increased, the lateral rigidity is reduced, and both turning performance and braking stability are secured to some extent.

In other words, it is possible to improve riding comfort and turning performance while ensuring braking stability.

Note that the installation posture of the suspension bush 1 is not limited to that of the above-described embodiment, and for example, it 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 can be sufficiently applied to other types of suspension stiffness control means as long as the stiffness can be controlled in two directions, and can also be applied to other types of suspensions.

Furthermore, as shown in Fig. 10, regardless of the presence or absence of turning,
During braking, control may also be considered in which only the longitudinal stiffness is largely adjusted in accordance with the amount of brake depression. That is, when the brake signal is determined to be present in step S3, the longitudinal stiffness is set in accordance with the amount of brake depression in step S5, and the longitudinal stiffness is adjusted in accordance with this set value in step S6. In this case, it is sufficient for the actuator to be able to adjust the stiffness in only one direction, and the lateral stiffness is fixed to an appropriately small size that ensures a certain degree of ride comfort and turning performance.

This provides an effect similar to that of the embodiment described above.

Further, the control performed by the control means (controller) 11 may be various types of control in addition to the control by the brake corresponding control unit 11a as described above, and when the brake is applied (braking), these controls are performed. By giving priority to the control by the brake corresponding control section 11a, other performance improvements can be achieved while ensuring braking stability.

[Effects of the Invention] As detailed above, according to the suspension alignment control device of the first embodiment of the present invention, there is provided a suspension stiffness adjusting means capable of adjusting the longitudinal stiffness of the suspension provided on a vehicle, and a The vehicle includes a control means for controlling the adjustment means, and a brake sensor capable of detecting the operating state of a brake provided on the vehicle.

The control means has a simple configuration in which the control means includes a brake corresponding control section capable of outputting an operation control signal to the suspension stiffness adjustment means so that the longitudinal stiffness of the suspension becomes high when the brake is applied based on information from the brake sensor. , after ensuring a certain degree of braking stability,
This has the advantage of improving riding comfort and turning performance.

Further, according to the suspension alignment control device of the second embodiment of the present invention, there is provided a suspension stiffness adjusting means that can adjust the longitudinal stiffness and lateral stiffness of the suspension provided in the vehicle, and a control that controls the suspension stiffness adjusting means. and a brake sensor capable of detecting the operating state of a brake provided on the vehicle, and a steering state sensor capable of determining whether the vehicle is in a straight-ahead state or a turning state, and the control means , outputs an operation control signal to the suspension stiffness adjustment means based on information from the brake sensor and the steering state sensor so that the longitudinal stiffness and lateral stiffness of the suspension are high when the vehicle is traveling straight when the brakes are applied. Braking stability is ensured by a simple configuration that includes a brake compatible control section that can output an operation control signal to the suspension stiffness adjustment means so that only the front and rear stiffness of the suspension is high when the vehicle is in a turning state when the brakes are applied. This has the advantage of improving ride comfort and turning performance.

[Brief explanation of drawings]

1 to 10 show a suspension alignment control device as an embodiment of the present invention, FIG. 1 is a block diagram showing its configuration, and FIG. Cross-sectional view as seen from Figure 2 (b
) is a sectional view taken along the line ■b-nb in Fig. 2(a), and Fig. 2(c
) is a cross-sectional view taken along the line l1c-IIc in Fig. 2(a), Fig. 3 is a schematic diagram showing an example of mounting on the suspension when viewed in the longitudinal direction of the vehicle, and Fig. 4 shows an example of mounting on the suspension. A schematic plan view, Fig. 5 is a detailed view showing an example of mounting on the suspension when viewed from the longitudinal direction of the vehicle, Fig. 6 is a plan view of main parts showing an example of mounting on the suspension, and Fig. 7 is on the suspension. 8 is a flowchart showing the control operation, FIG. 9 is a graph showing the stiffness setting characteristics by the control, and FIG. 10 is a flowchart showing the control operation of a modified example. be. 1- (Suspension bushing with rigidity adjustment mechanism or rigidity adjustment actuator), IA-・rigidity adjustment mechanism,
2-case, 3-shaft, 4.6-rubber body as elastic support member, 5-inner case, 7a. 7b--space as first oil chamber, 8a, 8b-space as second oil chamber, 9-reinforcing material, 10-hydraulic control system, 1
0 a - front and back rigidity control valve, 10 b - lateral rigidity control valve, 11 - controller, 1la - brake compatible control section, 12 - sensor group, 12a - brake sensor, 12
b - steering angle sensor as steering state sensor, 13 - orifice, 14 - oil pump, 15. 18 - accumulator, 16 - relief valve, 17 - one-way valve, 19 - oil reservoir, 20a to 20d - supply and discharge ports ,
21-wheel, 21a-knuckle, 22-strut, 2
3 - joint, 24 - lower arm, 25 - joint joint, 26 - body, 27 - bush, 28 - spring.

Claims (2)

[Claims] (1) It is equipped with a suspension stiffness adjustment means that can adjust the longitudinal stiffness of the suspension installed on the vehicle, and a control means that controls the suspension stiffness adjustment means, and is also capable of detecting the operating state of the brake installed on the vehicle. A brake corresponding control section is provided, which includes a brake sensor, and the control means is capable of outputting an operation control signal to the suspension stiffness adjustment means so that the front and rear stiffness of the suspension is increased when the brake is applied, based on information from the brake sensor. A suspension alignment control device characterized by: (2) a suspension stiffness adjustment means that can adjust the longitudinal stiffness and lateral stiffness of the suspension provided on the vehicle;
A control means for controlling the suspension stiffness adjustment means, a brake sensor capable of detecting the operating state of a brake provided on the vehicle, and a steering state capable of determining whether the vehicle is traveling straight or turning. the control means controls the suspension stiffness so that the longitudinal stiffness and lateral stiffness of the suspension are high when the vehicle is traveling straight when the brakes are applied, based on information from the brake sensor and the steering state sensor. A brake corresponding control section is provided which can output an operation control signal to the suspension stiffness adjusting means so that only the longitudinal stiffness of the suspension becomes high when the vehicle is in a turning state when the brakes are applied. A suspension alignment control device characterized by: