JPH085303B2 - Stabilizer control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a stabilizer control device capable of improving riding comfort and straight running performance during straight running.

[Prior Art] When a vehicle shifts to a turning traveling state, rolling occurs due to the action of centrifugal force. In this case, since the camber angle also changes with an increase in the roll angle, the canvas rust increases, leading to a decrease in maneuverability and stability. Therefore, in order to maintain the turning traveling state, it is necessary to frequently perform the correction steering. In order to suppress such rolling and enhance maneuverability and stability, for example, it is conceivable to set the spring constant of the suspension high. However, in this case, shocking vibrations, such as when traveling on a rough road, are not absorbed, and the riding comfort is reduced. Therefore, a stabilizer which acts as a spring and generates a restoring force only when the suspension positions of the left and right wheels are different is provided in the vehicle to suppress rolling.

However, even if the vehicle is not rolling,
For example, when one of the left and right wheels rides on a protrusion on the road surface, a difference occurs in the suspension position of the left and right wheels, so that the stabilizer generates a torsional elastic force and acts as a spring. For this reason, the ride comfort is reduced as in the case where the spring constant of the suspension is set high. As a countermeasure against such a problem, for example, a "stabilizer device" (Japanese Patent Application Laid-Open No. 61-64514) has been proposed. That is, the stabilizer and the wheel-side member are connected by a cylinder unit having two cylinder chambers formed by a piston and a cylinder body, and both cylinder chambers are connected by a switching valve to a pressure fluid source. This is a technique for adjusting the pressure to expand and contract the cylinder unit, positively utilizing the action of the stabilizer, and controlling the posture of the vehicle to prevent rolling during turning of the vehicle.

By the way, in the above-mentioned conventional technique, the pressure fluid from the pressure fluid source is supplied to the cylinder unit at the time of turning to control so as to stabilize the posture of the vehicle. However, if pressure fluid is supplied discontinuously or stepwise to the cylinder unit when performing such control, shocking vibration that gives an occupant an uncomfortable feeling, noise accompanying the vibration, and the like are generated in the vehicle. Then
The ride quality was getting worse. Therefore, the applicant of the present application is
When actively controlling the stabilizer, the "hydraulic stabilizer control device" is an improved technology that eliminates the discomfort felt by the occupant by continuously controlling the flow rate of the pressure fluid from the fluid pressure source to the cylinder unit with the flow control valve (Patent application Akira
62-148610).

[Problems to be Solved by the Invention] However, the above-mentioned improved technology is
While the vehicle speed is below the prescribed speed, the stabilizer does not function at all, and when the vehicle speed increases to, for example, 80 km / h or more, the stabilizer controls the full function of the stabilizer for the first time. When driving at medium or low speeds of 80 km / h or less, rolling tends to occur and the vehicle becomes unstable, and it is necessary to frequently perform correction steering. This becomes remarkable as the vehicle speed increases. Further, since the stabilizer that makes the vehicle speed a predetermined value suddenly functions, a shock is applied to the vehicle and the driver feels uncomfortable.

As described above, in the related art, no consideration is given to the straight running performance while the vehicle speed is equal to or lower than the predetermined value, and there is still room for improvement in the active control of the stabilizer.

The present invention has been made in view of the above problems,
Provided is a stabilizer control device capable of improving both straight traveling performance and riding comfort by controlling the stabilizer to gradually exhibit its original function as the vehicle speed increases during straight traveling. The purpose is to

[Means for Solving the Problems] As means for solving the above problems, the present invention connects both unsprung members which respectively support left and right wheels of a vehicle, as illustrated in FIG. Stabilizer M1, actuator M2 that changes the twisting force generated in the stabilizer by an external control signal, speed detection means M3 that detects the traveling speed of the vehicle, and steering angle detection means M4 that detects the steering angle of the vehicle. On the basis of the detected traveling speed and steering angle, when the vehicle is in a substantially straight traveling state, a vehicle speed responsive control is executed to input a control signal for increasing the torsional force of the stabilizer as the traveling speed increases to the actuator M2. When a predetermined turning state is reached, the steering angle sensitive control is input to input a control signal to the actuator M2 to increase the torsional force of the stabilizer as the steering angle increases. And control means M5 for changing and configured to include a.

The stabilizer M1 connects both unsprung members that respectively support the left and right wheels of the vehicle, and suppresses rolling by the twisting force generated when the vehicle tries to lean left and right when turning. It works.

The actuator M1 is for changing the torsional force generated in the stabilizer according to an external command. For example, a flow control valve that is interposed between at least one of the left and right unsprung members and the connecting portion of the stabilizer, and whose opening is adjusted by a control signal from the outside in the connecting passage between the hydraulic chambers on both sides of the piston. It can be realized by a hydraulic cylinder provided with. In addition, the stabilizer is divided into two parts at the central part of the torsion part (torsion bar part), and clutch plates which can be frictionally engaged with each other are respectively attached to both of the divided parts, and these clutch plates are connected to each other from the outside. A hydraulic cylinder that makes pressure contact according to a control signal may be mounted to adjust the degree of engagement between both clutch plates.

The speed detecting means M3 is for detecting the speed of the vehicle. For example, it can be realized by a reed switch type vehicle speed sensor provided inside the speedometer, or an electromagnetic pickup type vehicle speed sensor that detects the rotation speed of the output shaft of the transmission.

The steering angle detection means M4 is for detecting the steering angle of the vehicle. For example, a potentiometer disposed on a steering shaft and outputting a steering amount as an analog signal,
Alternatively, it can be realized by a steering sensor such as a rotary encoder that outputs a digital signal with high resolution.

The control means M5 is for inputting to the actuator a control signal calculated according to the vehicle speed and the steering angle.

[Operation and Effect] The stabilizer control device of the present invention switches between vehicle speed sensitive control and steering angle sensitive control according to whether the vehicle is traveling straight or traveling.

The vehicle speed response control is executed when the vehicle is traveling straight ahead. Due to this vehicle speed sensitive control, the stabilizer M1 gradually exhibits its original function as the vehicle speed increases during straight traveling. Therefore, when traveling at high speed, delicate rolling of the vehicle body is suppressed by the action of the stabilizer M1 to improve straight running performance, and when the vehicle speed is relatively low, the stabilizer M1 does not exhibit its original function so much. It is possible to prevent the stabilizer M1 from acting as a suspension spring when only the wheels pass over the unevenness of the road surface, and prevent the riding comfort from being impaired.

On the other hand, the steering angle sensitive control is executed during a predetermined turning traveling. By this steering angle sensitive control, the stabilizer M1 exerts a stronger torsional force as the steering angle becomes larger.
As a result, a stronger torsional force is exerted when a stronger lateral load is applied, and accurate rolling suppression control corresponding to the turning state becomes possible. Here, since the steering angle sensitive control is performed, a phenomenon such as a reverse roll is not caused at the time of a gentle turn such that rolling does not occur so much.

As described above, in the present invention, the straight rolling performance can be ensured by suppressing the delicate rolling during high-speed straight traveling without impairing the riding comfort at low speed, and the rolling caused by turning can be reversed. It is possible to suppress appropriately without causing.

That is, the present invention adopts a configuration in which the vehicle speed response control corresponding to the traveling speed and the steering angle response control corresponding to the steering angle are switched, thereby maintaining the original rolling suppression control during turning optimally. Actions desired when driving straight ahead, such as improving performance when driving straight ahead
This makes it possible to achieve both the effect and the action / effect desired during turning traveling accurately.

Further, according to the stabilizer control device of the present invention, unlike the conventional device, the stabilizer does not suddenly exert its function when the vehicle speed reaches a predetermined speed,
There is a side effect that a good driving feeling can be secured without giving the driver a feeling of discomfort.

[Embodiment] An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 2 shows a system configuration of a stabilizer control device according to an embodiment of the present invention.

As shown in FIG. 1, the stabilizer control device 1 includes a front stabilizer device 2 and an electronic control device (hereinafter simply referred to as an ECU) 3 that controls the stabilizer device 2.

The front stabilizer device 2 supplies a connection actuator 7 interposed between the left mounting portion of the front stabilizer bar 4 and the lower arm 6 of the left front wheel 5 and pressure oil boosted by the hydraulic source 8 to the connection actuator 7. A connecting unit 10 including a valve actuator 9 for supplying, a stabilizer link 13 for connecting between the right mounting portion of the front stabilizer bar 4 and the lower arm 12 of the right front wheel 11.
Is provided.

On the other hand, the left stabilizer of the rear stabilizer bar 14 and the left rear wheel
A stabilizer link 17 is provided between the lower arm 16 and the lower arm 16 to attach the rear stabilizer bar 14 to the right mounting portion and the right rear wheel 18.
The lower arm 19 and the lower arm 19 are connected by a stabilizer link 20.

The stabilizer control device 1 includes a vehicle speed sensor 21 that detects a vehicle speed and a steering sensor 22 that detects a steering angle as a detector.

Next, the configurations of the coupling unit 10 and the ECU 3 will be described with reference to FIG.

As shown in FIG. 3, the connecting unit 10 includes a connecting actuator 7, which adjusts the distance between the left mounting portion of the front stabilizer bar 4 and the lower arm 6 in accordance with the hydraulic pressure supplied from the valve actuator 9, and the above-mentioned distance (stroke). A stroke sensor 24 that detects the amount) and outputs it to the ECU 3 and a valve actuator 9 that supplies the pressure oil boosted by the hydraulic pressure source 8 to the connection actuator 7 according to the control of the ECU 3.

In the coupling actuator 7, a piston 32 in which a piston rod 33 is connected in series is slidably fitted in a cylinder 31, and the piston 32 connects the inside of the cylinder 31 to an upper chamber 35 having a port 35a and a port 36a. It is divided into the lower chamber 36 which has. The piston rod 33 is attached to the left mounting portion of the front stabilizer bar 4 while the cylinder 31
Are attached to the lower arms 6, respectively. Therefore, the stabilizer device 2 is configured to change the twisting force generated in the front stabilizer bar 4 by the movement of the piston 32 of the connecting actuator 7 over a predetermined stroke amount.

The hydraulic source 8 includes a hydraulic pump 53 having a constant flow rate driven by an output shaft 52 of the engine 51 and a reservoir 54 for storing hydraulic oil.

Further, the valve actuator 9 has a neutral position 41a and a contracted position 41b according to a control signal output from the ECU 3.
And a directional control valve 41 (4-port 3-position solenoid valve) that switches to the extended position 41c and a flow control valve (4-port 2-position solenoid valve) that continuously changes the opening according to the duty ratio control signal output from the ECU. Valve) 42.

Each port on the input side of the directional control valve 41 has a conduit 61,
A hydraulic pump 53 and a reservoir 54 are communicated with each other by 62.
Further, the flow control valve 42 is connected in parallel with the connecting actuator 7 connected to the output side of the directional control valve 41, and the ports on the output side thereof are connected to each other so that the directional control valve 41 The conduit 62 communicating with the reservoir 54
It is connected to the.

Further, the flow rate control valve 42 has a communication position 42a and a shutoff position 4a.
It is possible to switch between 2b and 2b at high speed according to the duty ratio control signal output from ECU3, and the opening area can be continuously adjusted from the fully open state (communication position 42a) to the fully closed state (cutoff position 42b). is there. In the present embodiment, when the duty ratio control signal is 100 [%], the flow rate control valve 42 is fully opened,
On the other hand, when the duty ratio control signal is 0 [%], the flow rate control valve 42 is set to be fully closed.

The ECU 3 described above has a CPU 3a, a ROM 3b,
It is configured as a logic operation circuit around M3c,
It is connected to the input unit 3e and the output unit 3f via d, and performs input / output with the outside. The detection signals from the above sensors are input to the input section 3e.
Is input to the CPU 3a via the output unit 3f, and the CPU 3a outputs a control signal to the direction switching valve 41 and the flow rate control valve 42 via the output unit 3f.

Next, the operation of the stabilizer control device in each traveling state will be described.

<When traveling straight ahead> When traveling straight ahead, the direction switching valve 41 is held at the neutral position 41a. On the other hand, the flow rate control valve 42 is held in the fully open state by the control signal of the duty ratio of 100 [%] while the vehicle speed is equal to or lower than the predetermined speed V1. Accordingly, while the vehicle speed is equal to or lower than the predetermined speed V1, the piston 32 of the connecting actuator 10 can freely slide, so that the connecting portion of the stabilizer 4 and the connecting portion of the lower arm 6 are in an unconnected state and the left and right wheels 5 , 11 can move up and down independently of each other. Therefore, the stabilizer 6 does not exhibit its original function and therefore does not act as a suspension spring, so that the riding comfort on a rough road is improved.

Further, the duty ratio of the control signal of the flow rate control valve 42 is gradually reduced as the vehicle speed increases until the vehicle speed increases above the predetermined speed V1 and reaches the predetermined speed V2, whereby the flow control valve 42 opens. It is controlled so that the degree gradually decreases.
For this reason, the movement of the piston 32 becomes slower as the vehicle speed increases, so that the stabilizer 6 gradually exhibits its original function. As a result, the straight running performance improves as the vehicle speed increases. Further, when the vehicle speed reaches the predetermined speed V2, the flow rate control valve 42 is controlled by the control signal having the duty ratio of 0 [%] and is held in the fully closed state. As a result, the piston 32 is completely locked, and the connecting portion of the stabilizer 4 and the connecting portion of the lower arm 6 are in a completely connected state, and the stabilizer 6 is in a state where the original function thereof is fully exhibited.

<Turning Travel> Next, turning travel will be described.

When turning right or left, the directional control valve 41 moves to the retracted position 41b.
Alternatively, the piston of the coupling actuator 10 is switched to the extended position 41c so as to suppress rolling that occurs in the vehicle.
The pressure oil from the hydraulic pump 53 is supplied to either the upper chamber 35 or the lower chamber 36 of 32. At this time, when the hydraulic pressure in the upper chamber 35 and the lower chamber 36 changes abruptly, the piston 32 moves abruptly to give a shock to the vehicle, so the duty ratio of the control signal for controlling the flow control valve 42 is increased. Is gradually changed to gradually change the flow rate of the pressure oil flowing into the upper chamber 35 and the lower chamber 36.

At the time of turning, the target stroke S of the piston rod 33 required to suppress rolling is calculated, and a control signal is output to the direction switching valve 41 and the flow rate control valve 42 based on the difference between this and the actual stroke T. It

First, when it is determined that the turning is started, the direction switching valve 41 corresponds to the turning direction and the contracted position 41b or the extended position 41c.
And the flow rate control valve 42 is duty ratio controlled to gradually reduce the opening degree. As a result, the pressure oil from the hydraulic pump 53 is gradually supplied to the connecting actuator 10 via the direction switching valve 41 and the flow rate control valve 42. Here, when the opening degree of the flow rate control valve 42 is large, the pressure oil returned to the reservoir 54 via the flow rate control valve 42 is supplied to the coupling actuator 10 as the opening degree of the flow rate control valve 42 gradually decreases. The flow rate of the pressurized oil gradually increases. Therefore, the piston rod 33 of the connecting actuator 10 gradually moves so as not to give a shock to the vehicle.

In the connected actuator 10, the pressure generated by the throttle effect when the pressure oil from the hydraulic pump 53 passes through the flow control valve 42 and the load applied to the connected actuator 10 are held in a balanced manner in a state where the connected actuator 10 is extended by a predetermined stroke. As a result, the stabilizer 4 is twisted and rolling of the vehicle is suppressed.

When the turning is completed, the opening degree of the flow rate control valve 42 is gradually increased. As a result, the upper chamber 35 or the lower chamber 36 of the connecting actuator 10 gradually communicates with the reservoir 54, and the torsional reaction force of the stabilizer 4 causes the piston rod 33 of the connecting actuator 10 to return to the free state. Here, since the opening degree of the flow rate control valve 42 gradually increases, it is prevented that the piston rod 33 suddenly moves and the vehicle is shocked.

Next, the operation of the stabilizer control device will be described with reference to the flowchart of FIG. 4 showing the control program executed by the electronic control device 3.

When the process is started, first, steps 110 and 120 are executed, and the vehicle speed V and the steering angle θ are read from the speed sensor 21 and the steering sensor 22, respectively.

In the following step 130, it is determined whether the current vehicle is turning right or left based on the steering angle θ read in step 120. If it is determined that the vehicle is turning right, the process proceeds to step 140.

In step 140, the map shown in FIG. 5 is read out, and it is determined from the vehicle speed V and the steering angle θ whether the current vehicle is in a substantially straight traveling state (A region shown in the same figure) or in a turning traveling state (in the same figure). (B area shown) is determined. That is, it is determined whether or not the stroke amount control of the piston 32 of the coupling actuator 10 is executed.

In step 150, it is determined whether the vehicle speed V is equal to or higher than the predetermined speed V1, and if it is determined that the vehicle speed V is lower than the predetermined speed V, the step
Move to 160.

In step 160, the flow control valve 42 is set to a duty ratio of 100.
By outputting the control signal of [%], the opening can be adjusted to 10
Set to 0 [%]. Therefore, as described above, the piston rod 33 of the coupling actuator 10 is in a completely free state, whereby the left and right wheels 5 and 11 are held in a vertically movable state independent of each other.

If it is determined in step 150 that the vehicle speed V is equal to or higher than the predetermined speed V1, the process proceeds to step 170.

In step 170, the map shown in FIG. 6 is read out, the opening degree of the flow rate control valve 42 set according to the vehicle speed is calculated based on the vehicle speed V, and the control signal of the duty ratio according to the opening degree is output. To control the opening of the flow control valve 42. Here, in the above map, the opening degree of the flow rate control valve 42 becomes 100% when the vehicle speed V is the predetermined speed V1, and gradually decreases as the vehicle speed increases, and the vehicle speed V becomes the predetermined speed V2. By the way, it is set to be 0%.

By executing step 170, when the vehicle speed is equal to or higher than the predetermined speed V1, the degree of freedom of movement of the piston rod 33 of the coupling actuator 10 decreases according to the vehicle speed, and thus the stabilizer 4 has its original function as the vehicle speed increases. Exert.

Next, when it is determined in step 140 that the vehicle is currently in the turning traveling state (region B shown in FIG. 5), the process proceeds to step 180.

In step 180, the target stroke S is calculated from the map of FIG. 5 by the interpolation method or the like. And the following steps
In 190, the position of the piston rod 33 of the coupling actuator 10 detected by the stroke sensor 24, that is, the current stroke T is read, and the process proceeds to the following Step 200,
It is determined whether or not the stroke T is the target stroke S.

When it is determined in step 200 that the target stroke S of the piston rod 33 and the actual stroke T are deviated, the process proceeds to step 210, and the switching direction of the directional control valve 41 and the flow rate control valve 42 are set so as to eliminate this deviation. The opening degree is controlled and the process returns to step 190 again.

If it is determined in step 200 that there is no deviation between the target stroke S and the actual stroke T, step 22
The flow shifts to 0, and the opening of the flow control valve 42 is maintained as it is, and the piston rod 33 is maintained at the target stroke S.

On the other hand, if it is determined in step 130 that the vehicle is making a left turn, the same processing (300) as in steps 140 to 210 is executed to control the stroke position in the opposite direction to the right turn.

As described above, in this embodiment, when the steering angle is equal to or less than the predetermined value and the vehicle is traveling substantially straight, the stabilizer 4 does not function at all while the vehicle speed is lower than the predetermined speed V1, so that the wheel 5 on one side is not operated. When only (11) passes over the uneven portion of the road surface, the wheels are allowed to move up and down independently, which prevents the ride comfort from being impaired. Further, when the vehicle speed is equal to or higher than the predetermined speed V1, the stabilizer 4 gradually exerts its original function as the vehicle speed increases, so that the rolling of the vehicle is effectively suppressed as the vehicle speed increases. In particular, the straight running performance required during high speed running is improved.

In this embodiment, the connecting unit 10 is arranged only on the left front wheel side, but for example, it is arranged on the left and right front wheels or on all four wheels so that each connecting actuator 10 can be controlled independently. You may comprise. Even when such a configuration is adopted, the same effects as those of the above embodiment can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention, FIG. 2 is a perspective view showing the system configuration as an embodiment of the present invention, and FIG.
FIG. 4 is a configuration diagram showing the hydraulic circuit and the electronic control device,
FIG. 5 is a flowchart showing a control program of the electronic control unit, FIG. 5 is a map characteristic diagram for obtaining the target stroke S, and FIG. 6 is a map characteristic diagram for obtaining the opening of the flow control valve. M1 (4) …… Stabilizer M2 …… Actuator (7 …… Coupling actuator) M3 …… Speed detection means (21 …… Speed sensor) M4 …… Steering angle detection means (22 …… Steering sensor) M5 …… Control means (3 ... Electronic control unit)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hidenori Ichimaru 1st Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (72) Inventor Osamu Yasuike 1st Toyota-cho, Aichi-prefector Toyota Motor Co., Ltd. ( 72) Inventor Masayuki Soga 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (56) Reference JP 60-60022 (JP, A) JP 60-25811 (JP, A) JP Sho 57-66009 (JP, A)

Claims (2)

[Claims] 1. A stabilizer for connecting both unsprung members supporting left and right wheels of a vehicle, an actuator for changing a torsional force generated in the stabilizer by an external control signal, and a traveling speed of the vehicle. Based on the detected traveling speed and steering angle, the twisting force of the stabilizer increases as the traveling speed increases in a substantially straight traveling state. A vehicle speed sensitive control is executed by inputting a control signal to be increased to the actuator, and when a predetermined turning state is reached, a steering angle sensitive control is performed to input a control signal to increase the torsional force of the stabilizer as the steering angle is increased. A stabilizer control device comprising: a switching control unit. 2. The actuator is interposed between at least one of the unsprung members and a connecting portion of the stabilizer, and is opened by a control signal from the outside into a communication passage between the hydraulic chambers on both sides of the piston. 2. A hydraulic cylinder having a flow control valve whose degree is adjusted, wherein the control means controls the opening of the flow control valve. Stabilizer control device.