JP3269242B2 - Braking force control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking force control device, and more particularly to improvement of running stability of a vehicle.

[0002]

2. Description of the Related Art During vehicle braking, a so-called load shift occurs. The front wheel contact load increases while the rear wheel contact load decreases. For this reason, the rear wheel slip tends to be excessive, and the proportion of the wheel cylinder pressure of the brake that suppresses the rotation of the rear wheel to the wheel cylinder pressure of the brake that suppresses the rotation of the front wheel is fixed at a certain ratio. It is performed to depressurize.

However, even when the proportioning valve is provided, when sudden braking is performed, the wheel cylinder pressure of the rear wheel is large, and the slip of the rear wheel is increased, so that traveling may be unstable. For this reason, Japanese Patent Application Laid-Open No. Hei.
No. 9, the anti-lock control device is provided to reduce the braking distance by controlling the wheel cylinder pressure of the front wheel and the wheel cylinder pressure of the rear wheel so that the slip of the wheel is within an appropriate range. At the same time, running stability is ensured while avoiding lack of lateral force.

[0004]

However, even with the provision of the antilock control device, it may be difficult to maintain the running stability of the vehicle. For example, in a vehicle having a high center of gravity with respect to the length of the wheel base, the load shift during braking is large, and the rear wheel ground contact load is greatly reduced. In particular, when the road surface friction coefficient is large and the vehicle body deceleration is large, the ground contact load on the rear wheels becomes extremely small, and the lateral force for maintaining the lateral position of the rear wheels becomes small, resulting in unstable running. Even if the wheels are not locked by performing the anti-lock control, it is difficult to maintain the running stability if the rear wheel ground contact load is too small. Note that “large vehicle body deceleration” means that the degree of reduction in vehicle body speed is large. The rate of change of the vehicle body speed with respect to time is acceleration. Generally, the rate of increase of the vehicle body speed is represented by a positive value. Therefore, when the vehicle body speed decreases, the change rate becomes a negative value. However, since the magnitude of the negative value is opposite to the magnitude of the absolute value, and it is troublesome to handle negative acceleration, in this specification, the deceleration whose sign direction is opposite to that of the acceleration is used. It is what it was.

[0005] This problem is exacerbated in hydraulic brake systems without antilock control. In a hydraulic brake device with an anti-lock control device,
As a secondary effect of preventing the wheel from slipping excessively in the circumferential direction (front-rear direction), excessive slip in the axial direction (lateral direction) of the wheel is also prevented to some extent. This is because it cannot be expected in a hydraulic brake device having no.

[0006] The invention according to claim 1, has been made as object to provide a brake force control apparatus which can secure a running stability of the vehicle, the invention of claim 3, the left and right front wheels and It is an object of the present invention to provide a braking force control device capable of ensuring particularly good running stability in a vehicle in which rear wheels are independently subjected to antilock control.

[0007]

According to the first aspect of the present invention, there is provided a braking force control apparatus comprising:
A brake that suppresses rotation of the front and rear wheels,
(B) Reduce the wheel cylinder pressure of the front wheel brake
(C) a hydraulic control device for the front wheels that also increases and decreases
Increase wheel cylinder pressure of rear wheel brake at least
And a hydraulic pressure control device for a rear wheel, and (D) them
Controls the front wheel hydraulic pressure control device and the rear wheel hydraulic pressure control device.
To keep the slip of the front and rear wheels in the proper range.
Anti-lock control means and (E) anti-lock when the vehicle body deceleration increases in a state satisfying a predetermined condition.
The control of the rear wheel hydraulic pressure control device by the control means
Of the time when wheel cylinder pressure is reduced, the front wheel
When the wheel cylinder pressure of the vehicle is in a state where it can be increased
The front wheel pressure control system controls the front wheel
Front wheel cylinder pressure suppression hand that holds the Linda pressure
And a step . In the invention of claim 2,
In such a braking force control device, a hydraulic pressure control device for a front wheel is provided.
But the wheel cylinder pressure of each brake on the left and right front wheels
For the left front wheel to increase and decrease independently at least
Including hydraulic pressure control and right front wheel hydraulic pressure control, rear wheel
The hydraulic pressure control system for the left and right rear wheels
At least increase and decrease independently of each other
Hydraulic control device for the left rear wheel and hydraulic control device for the right rear wheel
Anti-lock control means for those left front wheels,
Hydraulic pressure control devices for the right front wheel, left rear wheel, and right rear wheel
Control to keep the left and right front and rear wheels in the proper range
Shall be kept.

Further, the braking force control device according to the third aspect of the present invention includes: (a) a brake for suppressing the rotation of each of the left and right front wheels and the left and right rear wheels; and (b) a wheel cylinder pressure for each of the left and right front wheels. A left front wheel hydraulic pressure control device and a right front wheel hydraulic pressure control device for independently increasing and decreasing at least independently; and (c) a left rear wheel wheel pressure for at least independently increasing and decreasing the wheel cylinder pressure of each brake of the left and right rear wheels. (D) controlling the hydraulic pressure control devices for the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel by controlling the respective hydraulic pressure control devices for the left and right rear wheels; (E) anti-lock control means for maintaining slip of the front wheel and rear wheel within appropriate ranges, and (e) anti-lock control means when vehicle body deceleration increases in a state satisfying a predetermined condition. At least a portion of the time when either one of the wheel cylinder pressure of the left and right rear wheels is reduced,
Among the left front wheel hydraulic pressure control device and the right front wheel hydraulic pressure control device, those corresponding to the front wheels located on the diagonal line of the vehicle with respect to the rear wheel whose wheel cylinder pressure is reduced, including holding, increase By controlling in a manner that does not include
It is configured to include a front wheel cylinder pressure suppressing means for suppressing an increase in the wheel cylinder pressure of the front wheel.

[0009]

In the braking force control device according to the first aspect of the present invention, when the brake is operated and the rotation of the wheels is suppressed, the load movement increases as the vehicle body deceleration increases, and the front wheel contact load increases. As a result, the running load becomes unstable due to a decrease in the rear wheel contact load. However, when the vehicle body deceleration increases while satisfying the predetermined condition , the rear wheel
When the Linder Pressure is Reduced by Antilock Control
Out of which the wheel cylinder pressure of the front wheel is increased
The front wheel cylinder pressure is maintained
You. As a result, an increase in the vehicle body deceleration is suppressed, a decrease in the rear wheel contact load is suppressed, and lateral force of the rear wheel is secured. Ma
Also, whether the wheel cylinder pressure of the front wheels can be increased
The front wheel contact load
Of the rear wheel contact load is reduced.
The arrangement is loosened and running stability is improved. Rear wheel ground load
If the slope of the decrease in weight becomes gentle, sudden rear wheel skidding
Is avoided, making it easier for the driver to deal with it.
This improves running stability.

State in which antilock control has not been started
In the front wheel slip is not large, front wheel Siri
To increase vehicle pressure further to increase vehicle deceleration.
Is possible, and the front wheel slips excessively
There is room until the separation increases, or running stability decreases
I can afford it. In such a state that it can rise
Control the rise in the wheel cylinder pressure of the front wheels.
Although the braking distance will be slightly longer, the rear wheel touches down
Prioritize ensuring running stability by suppressing load reduction
Sometimes it is better.

Note that anti-lock control is performed for the front wheels.
When the front wheel cylinder pressure increases
Has already been suppressed. In this case, the front wheel
Cylinder pressure suppression means increases the wheel cylinder pressure of the front wheels.
The size may be further suppressed, or not
May be. Of course, from the viewpoint of suppressing the reduction of the rear wheel contact load
The former is preferred. On the other hand, the anti-
Control means and front wheel cylinder pressure suppressing means.
Can be operated simultaneously, but the control is complicated.
Or the control accuracy often decreases,
Prioritize one of the operations, especially anti-lock
It is also possible to prioritize the operation of the control means.

Further , each hydraulic pressure control device for the front wheel and the rear wheel is provided.
Is to increase and decrease the wheel cylinder pressure
Or increase or maintain wheel cylinder pressure
And may be reduced. Wheel syringe
When the hydraulic pressure is maintained, the hydraulic pressure control
It is not necessary to be in a state that can be held only,
The repeated increase and decrease in steps substantially reduces the front wheel
And can maintain the wheel cylinder pressure of the rear wheels.
You may. The “rear wheel cylinder pressure” according to claim 1
Is reduced, "and the front wheel cylinder pressure increases.
”,“ The front wheel cylinder pressure is maintained.
In each case, the wheel cylinder pressure is substantially reduced.
Small, increased, or maintained.

Further, each hydraulic pressure control for the front wheels and the rear wheels
The device is a braking force control device according to claim 2 of the present invention.
Adjust the wheel cylinder pressures of the left and right front and rear wheels.
The shift is not limited to the one that increases and decreases independently.
Wheel cylinder pressure common to right front wheel and rear wheel
Increase or decrease, or only the rear wheel
Increasing and decreasing wheel cylinder pressure through
And so on. The braking force control device according to claim 2,
When the rear wheel cylinder pressure is reduced
Increase the wheel cylinder pressure of both the left and right front wheels.
The wheels on both the left and right front wheels.
Or maintain the cylinder pressure, or use one of the left and right front wheels.
For example, the wheel cylinder pressure can be maintained.

In the vehicle equipped with the braking force control device according to the third aspect of the present invention, anti-lock control is independently performed for each of the left and right front wheels and the rear wheels if the slip increases beyond an appropriate range. . In addition, when the vehicle deceleration increases while satisfying a preset condition, the rear wheels
At least part of the time when the wheel cylinder pressure is reduced, after the wheel cylinder pressure is reduced
Front wheel cylinder located diagonally to the wheel
The pressure is controlled in a manner that includes holding and does not include increase, and a decrease in the rear wheel contact load is suppressed. The anti-lock control is performed on the rear wheels when the rear wheels have a large slip and the frictional force in the front-rear direction tends to be insufficient, and at this time, the frictional force in the lateral direction also tends to be insufficient, and running stability may be insufficient. There is. Nevertheless, if the wheel cylinder pressure of the front wheel increases, the lateral force of the rear wheel further decreases due to the decrease of the ground contact load. Therefore, at least one time during the rear wheel anti-lock control, the increase in the wheel cylinder pressure of the front wheel is suppressed, the decrease in the rear wheel contact load is suppressed, and the running stability is improved.

As described above, for the left and right front wheels and the rear wheels
Each hydraulic pressure control device can always be in a state exclusively for holding.
It does not need to be
With a few repetitions, the wheel cylinder pressure is substantially maintained
May be obtained, and the claim 3
The "not included" substantially increases the wheel cylinder pressure.
This refers to a control mode that is not performed.

[0016]

As described above, according to the first aspect of the present invention, the increase of the deceleration is suppressed by maintaining the wheel cylinder pressure of the front wheel, and the reduction of the ground contact load of the rear wheel is suppressed. And running stability can be improved. Therefore, when a vehicle with a high center of gravity relative to the length of the wheelbase is traveling on a road surface with a high coefficient of friction, even when sudden braking is performed, the ground contact load on the rear wheels becomes too small and traveling becomes unstable. Before this, the wheel cylinder pressure of the front wheels can be suppressed, and running stability can be ensured. Further, control of the wheel cylinder pressure of the front wheels can be performed by using a front wheel hydraulic pressure control device for antilock control, and there is no need to provide a dedicated hydraulic pressure control device, so that the device can be easily and inexpensively configured. be able to.

According to the invention of claim 3 , in addition to the effect of the invention of claim 1, the wheel cylinder pressure is reduced. The wheel cylinder of the front wheel located on the diagonal line of the vehicle with respect to the rear wheel. Since the pressure rise is suppressed,
Further, running stability can be improved. When antilock control is required on only one of the left and right rear wheels on a road surface having a high friction coefficient, the vehicle body is often in a diagonally forward-downward posture. An example is a case where braking is performed during turning of the vehicle. In this case, due to the centrifugal force acting, the ground contact load of the front wheel on the outside of the turn is large, and the vehicle body is in a diagonally forward-downward position with its front wheel side lowered, and the rear side of the inside of the turn on the diagonal position with respect to the front wheel is In the vicinity of the ring, it rises obliquely backward. Therefore, the contact load of the rear wheel is reduced, and antilock control is required. Therefore, wheel lock by anti-lock control
That suppresses the increase of the front wheel of the wheel cylinder pressure at the diagonal positions with respect to the rear wheel on the side where the reduction of the cylinder pressure is performed, that it suppressed the front wheel braking force on the side where the vehicle body is low In addition, it is possible to reduce the diagonally forward-downward posture of the vehicle body, suppress a decrease in the ground contact load of the rear wheel on the inside of the turn, and improve running stability.

Further, when the road surface is a staggered road having a different coefficient of friction between left and right, running stability can be ensured. When the road surface is a straddling road, the magnitudes of the left and right braking forces of the vehicle become unbalanced, and the traveling becomes unstable.
At this time, the slip of the rear wheel traveling on the side with a low friction coefficient of the road surface becomes large first, and the anti-lock control is usually performed, and the wheel cylinder pressure of the rear wheel is reduced.
By suppressing the increase in the wheel cylinder pressure of the front wheels located on the diagonal line with the control , the braking force of the front wheels is suppressed, the imbalance of the left and right braking forces of the vehicle is eased, and the running stability is improved. is there.

[0019]

According to the present invention, according to the present invention,
In addition to the power control device, the following braking force control devices are also available.
Can be (1) A brake for suppressing the rotation of the front wheel and the rear wheel, and a front wheel cylinder pressure for suppressing an increase in the wheel cylinder pressure of the front wheel brake when the vehicle body deceleration increases in a state satisfying a predetermined condition. A braking force control device comprising: a suppression unit.

The wheel cylinder pressure of the front wheel is the vehicle deceleration.
Is suppressed when it increases while satisfying the predetermined condition.
The vehicle deceleration satisfies the predetermined conditions
Increase when the condition is met
You may win. Pre-defined conditions, and further
The matter will be described later. Above front wheel cylinder pressure
The rise is to maintain, decrease and increase the front wheel cylinder pressure.
Of one or more aspects of the reduction of the large gradient
Such a front wheel can be suppressed by a combination
The rear wheel contact pressure
Ground load is reduced or increased, or reduced
Or the same size.

(2) A front wheel hydraulic pressure control device for at least increasing and decreasing the wheel cylinder pressure of the front wheel brake, a rear wheel hydraulic pressure control device for at least increasing and decreasing the wheel cylinder pressure of the rear wheel brake, Anti-lock control means for controlling the front wheel hydraulic pressure control device and the rear wheel hydraulic pressure control device to keep the slip of the front wheel and the rear wheel within an appropriate range, and the front wheel cylinder pressure suppressing means comprises Means for controlling the hydraulic pressure control device for the vehicle to suppress an increase in the wheel cylinder pressure of the front wheels
The braking force control device according to the above mode (1) .

(3) The anti-lock control means separately performs anti-lock control on a front wheel and a rear wheel, and the front wheel cylinder pressure suppressing means operates at least at one time during the anti-lock control on the rear wheel. The braking force control device according to the above mode (2) , which suppresses an increase in the wheel cylinder pressure of the front wheels. The suppression of the wheel cylinder pressure of the front wheels may be alleviation of increase, prevention (retention) of increase, or decrease.

In the braking force control device described in this section ,
At least one time during the rear wheel anti-lock control, an increase in the wheel cylinder pressure of the front wheels is suppressed, whereby a decrease in the rear wheel contact load is suppressed, and running stability is improved. As described above, the anti-lock control is performed on the rear wheels when the rear wheels have a large slip and the frictional force in the front-rear direction and the lateral frictional force are insufficient, so the vehicle body deceleration is determined in advance. It is reasonable to operate the front wheel cylinder pressure suppression means when both the condition that the condition is satisfied and the condition that the anti-lock control is performed on the rear wheel are satisfied. .
In this case, “the anti-lock control is performed on the rear wheels” is the “further condition”.

(4) Wheel brakes for the left and right front brakes
At least increase and decrease independently of each other
Hydraulic control device for the front left wheel and hydraulic control device for the front right wheel
And the wheel cylinder pressures of the left and right rear brakes.
Left rear wheels independently increasing or decreasing at least
Pressure control device for right and rear right wheel, and those
Hydraulic pressure for front left wheel, front right wheel, rear left wheel and rear right wheel
Control the control unit to slip the left and right front and rear wheels.
And a anti-lock control means for maintaining the proper range, the full
The front wheel cylinder pressure suppression means
At least one time during antilock control,
On the other hand, the wheel cylinder of the front wheel located on the diagonal of the vehicle
(1) to (3).
A braking force control device according to any one of the preceding claims.

[0025] (5) the front wheel cylinder pressure suppression means, is to suppress the increase of the front wheel of the wheel cylinder pressure when the vehicle deceleration is above a set value (1) term
(4) The braking force control device according to any one of (4) . This section
In the braking force control device described in (1) , “the vehicle body deceleration is equal to or more than a set value” is a “predetermined condition”. The set value of the vehicle deceleration is set to a value at which if the vehicle deceleration further increases, the running becomes unstable due to the excessive decrease of the rear wheel contact load. The performance is improved.

(6) The rear wheel cylinder pressure for holding the wheel cylinder pressure of the front wheel at least at a part of the time when the wheel cylinder pressure of the rear wheel is reduced by the anti-lock control of the rear wheel. The braking force control apparatus according to any one of the above modes (2) to (5) , including a front wheel cylinder pressure holding means at the time of decrease.

(7) The front wheel cylinder pressure holding means is a rear wheel antilock start time holding means for holding the front wheel wheel cylinder pressure when the antilock control is started for the rear wheel. The braking force control device according to any one of the above items (2) to (5) .

[0028] In the braking force control device described in this section, the wheel cylinder pressure of the front wheel is held when the antilock control is started for the rear wheel. Regardless of whether the wheel cylinder pressure of the rear wheel is decreasing , holding or increasing , the wheel cylinder pressure of the front wheel is kept constant while the anti-lock control is being performed on the rear wheel. In addition, a reduction in the rear wheel contact load is prevented, and the running stability is improved. Further, if the wheel cylinder pressure of the front wheels is maintained, the front wheel braking force can be obtained as compared with the case where the wheel cylinder pressure is reduced, and the running stability can be improved while the reduction of the braking force is kept small.

If the anti-lock control is started for the front wheels when the anti-lock control is started for the rear wheels, the operation of the front wheel cylinder pressure suppressing means is prohibited and the anti-lock control for the front wheels is stopped. Is desirably continued. In this case, storage means for storing the wheel cylinder pressure of the front wheel when the anti-lock control is started for the rear wheel, and restriction so that the wheel cylinder pressure of the front wheel does not exceed the stored value even during the anti-lock control. It is also possible to provide a restricting means.

If the anti-lock control is not started for the front wheels when the anti-lock control is started for the rear wheels, the front wheel cylinder pressure suppressing means also keeps the wheel cylinder pressure of the front wheels maintained. It is preferable that the monitoring of the slip condition of the front wheels is continuously performed, and if the necessity of the antilock control arises, it is desirable that the holding by the front wheel cylinder pressure suppressing means is released and the antilock control is started.

(8) The front wheel cylinder pressure suppressing means is a rear wheel following front wheel cylinder pressure suppressing means for starting the same antilock control for the front wheels as for the rear wheels when the antilock control is started for the rear wheels. (2) The braking force control device according to any one of the items (5) to (5) .

In the braking force control device described in this section ,
If the anti-lock control has not been started for the front wheels yet, the anti-lock control is started to suppress an increase in the wheel cylinder pressure of the front wheels. When the anti-lock control is started for the rear wheel, if the anti-lock control has already been performed for the front wheel, the anti-lock control may be continued as it is. You may make it switchable. In the former case, the control emphasizes securing of the braking force of the front wheels, and in the latter case, the control emphasizes running stability.

(9) When the front wheel cylinder pressure suppressing means starts the antilock control for the rear wheel, the front wheel cylinder pressure suppression means sets the antilock control reference value for the front wheel to a value at which the antilock control is performed at a slip ratio smaller than usual. The braking force control device according to any one of the above items (2) to (5), which is a front wheel anti-lock control reference value changing means for changing the braking force to the reference value. The front wheel anti-lock control reference value is a reference value that is compared with an actual value to generate a wheel cylinder pressure increase / decrease command during execution of the anti-lock control. is there. The reference value of the slip-related amount includes a direct slip-related amount reference value directly related to slip, such as a reference slip ratio and a reference slip amount, and a target wheel determined based on the direct slip-related amount reference value. There is a reference wheel speed as a speed and an indirect slip related amount reference value indirectly related to slip, such as a reference wheel acceleration used in combination with or used alone. The anti-lock control reference value may be changed at the start of the anti-lock control for the rear wheel, and may be kept changed until the end of the anti-lock control for the rear wheel, or the anti-lock control reference value may be changed. At the start of lock control, the anti-lock control reference value is changed to a value at which anti-lock control is performed at a smaller slip rate than normal, and thereafter, the anti-lock control is changed at a fixed rate or a fixed amount over time, and the anti-lock control is performed at a normal slip rate. The value at which the control is performed may be gradually restored. In the latter case, there is a possibility that the running stability may decrease again, but if the change is gradual, the driver can easily cope with the change.

In the braking force control device according to the present invention , if the front wheel anti-lock control reference value is changed by the front wheel anti-lock control reference value changing means, the front wheel slip ratio or the slip amount becomes smaller than normal. Anti-lock control is started, and an increase in the wheel cylinder pressure of the front wheels is suppressed, so that running stability is improved. In many cases, depending on the degree of change of the front wheel anti-lock control reference value, it is possible to start the anti-lock control simultaneously with the change of the front wheel anti-lock control reference value. In addition, the anti-lock control for the front wheels is also performed for the time being, even if it does not maximize the braking performance of the front wheels. Accordingly, the front wheel cylinder pressure control that follows is executed.

(10) The front wheel anti-lock control reference value changing means decreases the front wheel anti-lock control reference value as the vehicle deceleration during the rear wheel anti-lock control or the wheel cylinder pressure of the rear wheel increases. The braking force control device according to mode (9) , wherein the braking force control device is a road surface friction coefficient corresponding antilock control reference value changing unit that changes the slip ratio to a value at which antilock control is performed.

The anti-lock control is a control for controlling the wheel cylinder pressure so that the wheel slip ratio is in an appropriate range. The anti-lock control is a control that uses the friction coefficient of the road surface as effectively as possible. Low pressure,
Alternatively, a small vehicle body deceleration means a small road surface friction coefficient. If the anti-lock control is being performed, the road surface friction coefficient can be determined based on the wheel cylinder pressure or the vehicle body deceleration, and the anti-lock control reference value that determines the necessity of suppressing the increase in the front wheel cylinder pressure as the road surface friction coefficient increases. Is changed to a value at which the antilock control is performed with a small slip ratio, the front wheel braking force can be suppressed small, and both the running stability and the braking force can be secured. In order to suppress the front wheel braking force during the rear wheel anti-lock control, the front wheel slip ratio is made smaller than the slip ratio at which the maximum friction force is obtained. Therefore, the slip ratio for suppressing the braking force of the front wheels should also be reduced as the road surface friction coefficient increases, since the slip ratio that can obtain the above is small. The front wheel anti-lock control reference value may be changed continuously or stepwise according to a change in the road surface friction coefficient. To change the front wheel anti-lock control reference value at the start of the rear wheel anti-lock control according to the road surface friction coefficient and leave it changed until the rear wheel anti-lock control ends, start the rear wheel anti-lock control. The changed value may be maintained as it is, or may be changed continuously or stepwise according to the change of the road surface friction coefficient after the front wheel anti-lock control reference value is changed once.

[0037] (11) the front wheel cylinder pressure suppression means comprises a road surface friction coefficient corresponding vehicle deceleration set value changing means for setting the vehicle deceleration setting the larger value the larger the road coefficient of friction (5) Any one of items- (10)
4. The braking force control device according to any one of claims 1 to 3. If the grounding load is the same,
The greater the road surface friction coefficient, the greater the lateral force of the wheel. Therefore, when the road surface friction coefficient is large, the vehicle body deceleration when the lateral force of the wheels becomes insufficient and the traveling performance becomes unstable is large, and the vehicle body deceleration to start suppressing the increase in the wheel cylinder pressure of the front wheels is set. The value can be increased.
If the set value of the vehicle body deceleration is changed in accordance with the road surface friction coefficient in this manner, a large vehicle body deceleration can be obtained when the road surface friction coefficient is large, and the sacrifice of the braking force can be reduced,
The vehicle can be effectively braked while maintaining running stability.

(12) When the front wheel cylinder pressure suppressing means has satisfied at least one of the condition that the rising gradient of the vehicle body deceleration with respect to the master cylinder pressure has started to decrease and that the vehicle speed has become equal to or less than the set value. (1) to start the suppression of the wheel cylinder pressure of the front wheels.
The braking force control device according to any one of the above items 1) . Note in this section
The above-mentioned conditions can be used alone or in combination with the above-mentioned “the vehicle body deceleration becomes equal to or more than a set value”. In the former case , the conditions described in this section are “ In the latter case, both conditions may be considered as “predetermined conditions”, or one of them may be “predetermined conditions” and the other may be “predetermined conditions”. It can also be considered a "condition."

In a state where the road surface friction coefficient has a sufficient margin, the vehicle body deceleration increases substantially in proportion to the master cylinder pressure (or the brake operating force) (with a substantially constant rising gradient), but the road surface friction coefficient has a margin. The smaller the slope, the smaller the ascending gradient. Under these circumstances, the lateral force of the rear wheel is often insufficient, so it is meaningful to operate the front wheel cylinder pressure suppressing means to prevent the rear wheel load from being further reduced when the above condition is satisfied. Yes, "the vehicle deceleration itself must be equal to or greater than the set value" is a "predetermined condition."
It is possible to improve the running stability while keeping the sacrifice of the braking force small.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a system diagram showing a vehicle hydraulic brake device provided with an antilock control device, and reference numeral 10 in the figure denotes a brake pedal. When the brake pedal 10 is depressed, of the two pressurizing chambers of the master cylinder 12,
The hydraulic pressure generated in one pressurizing chamber is applied to the front wheel cylinder 1 of the brake of the left front wheel 16 by the liquid passage 14.
And transmitted to the rear wheel cylinder 24 of the brake of the right rear wheel 22 via the proportioning valve 26 by the liquid passage 20. The hydraulic pressure generated in the other pressurizing chamber is transmitted to the front wheel cylinder 32 of the brake of the right front wheel 30 by the liquid passage 28, and is transmitted to the rear wheel cylinder 38 of the brake of the left rear wheel 36 by the liquid passage 34. It is transmitted via the proportioning valve 40. The device of this embodiment is a diagonal type two-system hydraulic brake device.

The left and right front wheels 16, 30 and rear wheels 36, 2
2 are independently antilock controlled. The configuration of the antilock control device provided in each system of the four wheels is the same, and the left front wheel 16 will be representatively described. A normally open first solenoid on-off valve 50 is provided in the liquid passage 14, and a reservoir 54 is formed by a reservoir passage 52 in a portion of the liquid passage 14 between the first solenoid on-off valve 50 and the front wheel cylinder 18. It is connected.

The reservoir passage 52 is provided with a normally closed second solenoid on-off valve 56, and the wheel cylinder pressure is changed by a combination of opening and closing of the first and second solenoid on-off valves 50 and 56. In this embodiment, the first and second solenoid on-off valves 50 and 56 are opened and closed such that the wheel cylinder pressure (here, the hydraulic pressure of the front wheel cylinder 18) is controlled in the following four control modes.

A pressure increasing mode in which the front wheel cylinder 18 is communicated with the pressurizing chamber of the master cylinder 12, and the wheel cylinder pressure is increased by transmitting the hydraulic pressure (referred to as master cylinder pressure) generated in the pressurizing chamber of the master cylinder 12. A pressure reduction mode in which the front wheel cylinder 18 communicates with the reservoir 54 to reduce the wheel cylinder pressure by discharging brake fluid;
8 is switched between the pressure increasing mode and the pressure maintaining mode in which the communication between the master cylinder 12 and the reservoir 54 is interrupted and the wheel cylinder pressure is maintained at the same level, and the wheel cylinder pressure is increased. The first and second solenoid on-off valves 50 and 56 are opened and closed so as to obtain a gradual pressure increasing mode in which the pressure is increased at a gentler gradient than in the pressure mode. The liquid passage 14 is provided with a bypass passage 58 that bypasses the first electromagnetic opening / closing valve 50 and a check valve 60 so that the brake fluid returns to the master cylinder 12 quickly when the brake is released.

The brake fluid discharged from the front wheel cylinder 18 to the reservoir 54 is pumped up by a pump 66 having two check valves 64 driven by a pump motor 68, and the first electromagnetic force in the fluid passage 14 is increased. It is returned from the on-off valve 50 to the part on the master cylinder 12 side. The antilock control device according to the present embodiment is of a reflux type. 7
Numeral 0 is a shock absorber for absorbing the pulsation of the brake fluid. The pump 66 is provided with a relief valve (not shown).
The discharge pressure is prevented from exceeding the set value.

The antilock control is performed by an antilock control unit 80 mainly composed of a computer.
The rotation speeds of the left and right front wheels 16, 30 and rear wheels 36, 22 are detected by rotation speed sensors 82, 84, 86, 88 and supplied to an antilock control unit 80. Wheel deceleration,
The vehicle speed and vehicle deceleration are calculated. A brake switch 92 for detecting depression of the brake pedal 10 is also connected to the antilock control unit 80.
The antilock control unit 80 calculates the calculated wheel speed,
Based on the wheel deceleration, the vehicle speed, the vehicle deceleration, and the brake operation information from the brake switch 92, the first,
Opening and closing of the second solenoid on-off valves 50 and 56 and the pump motor 6
8 to perform antilock control.

As shown in FIG. 3, the RAM of the computer of the antilock control unit 80 has a control mode memory 96, a counter 98, an antilock control flag 10
0, a slowly increasing pressure mode setting flag 102 and the like are provided together with the working area. The control mode memory 96 includes:
The control mode for the hydraulic pressure of each of the front and rear wheel cylinders 18, 32, 24, 38 is provided for each of the four wheels. An anti-lock control flag 100 is also provided for each of the four wheels, and the set indicates which of the wheels the anti-lock control has started. The ROM stores a control mode change routine shown by a flowchart in FIG. 1, a main routine shown in FIG. 4, a control mode setting routine shown in FIG. 5, and the like.

Next, the operation will be described. When braking is not performed, the first and second solenoid on-off valves 50 and 56 are at the positions shown in FIG.
The master cylinder pressure of master cylinder 12 is transmitted to 8, 32, 24, and 38. Therefore, when the brake pedal 10 is depressed, the master cylinder pressure is increased to the front and rear wheel cylinders 18, 32, 2.
4, 38, and the rotation of the left and right front wheels 16, 30 and the rear wheels 22, 36 is suppressed.

When the braking force is excessive with respect to the coefficient of friction of the road surface and the slip ratio of the wheel increases beyond an appropriate range, antilock control is performed. By opening and closing the first and second solenoid on-off valves 50 and 56, the wheel cylinder pressure is increased, gradually increased, reduced and maintained, and the slip ratio of the wheel is maintained in an appropriate range.

The antilock control will be described with reference to a flowchart. The main routine of FIG. 4 is executed at the same time when the power is turned on.
6, initial settings such as resetting of the counter 98, the anti-lock control flag 100, and the slow pressure increase mode setting flag 102 are performed.

Next, S2 is executed, and after the detection signals of the brake switch 92 and the rotation speed sensors 82 to 88 are read, in S3, the wheel speed Vw and the wheel deceleration V
w 'is calculated. The wheel deceleration Vw ′ is calculated based on the amount of change in the wheel speed Vw per unit time or a fixed time (for example, the execution cycle time of the main routine) (The amount obtained by subtracting the speed Vw).

Subsequently, in S4, the vehicle speed _VSO is estimated, and the vehicle deceleration _VSO 'is calculated. The vehicle speed V _SO is estimated based on the highest wheel speed Vw among the wheel speeds Vw of the four wheels. Hereinafter, the vehicle speed V _SO obtained by this estimation is referred to as an estimated vehicle speed V _SO . Vehicle deceleration V _SO ', the unit time or a certain time (e.g., cycle time execution of the main routine) per estimated amount of change in vehicle speed V _SO (in S4 the vehicle from the speed V _SO previous S4 in runtime the current (The amount obtained by subtracting the vehicle speed V _SO at the time of execution).

Next, at S5, the brake switch 92
Is ON, it is determined whether or not the brake is operated. If the brake pedal 10 is not depressed and the detection signal of the brake switch 92 is OFF, the determination result of S5 is NO. And
After all the control modes of the wheel cylinder pressures of the four brakes are set to the pressure increasing mode in S11 and the counters and flags are reset, S1 is executed.
At 0, control signals for the first and second solenoid valves 50 and 56 are output. In this case, the control mode is set to the pressure increasing mode in S11, and the control mode memory 96
The first solenoid on-off valve 5 is set in the pressure increasing mode in which the wheel cylinder pressure increases based on the control mode stored in the first solenoid valve 5.
A control signal is output for setting 0 to the open state and closing the second electromagnetic on-off valve 56.

When the brake pedal 10 is depressed,
If the determination result in S5 is YES, S6 is executed, and it is determined whether or not the estimated vehicle speed V _SO is equal to or less than a set value. Large error of the wheel speed Vw during low-speed running, it is not possible to accurately estimate the vehicle speed V _SO, the anti-lock control is better not performed. Therefore, the determination in S6 is performed, and if the estimated vehicle speed V _SO is equal to or less than the set value, S
The determination result of 6 is YES, and S11 is executed, so that the antilock control is not performed.

If the estimated vehicle speed V _SO is larger than the set value, the determination result in S6 becomes NO, and S7 is executed to set the control reference wheel speed Vs. Control reference wheel speed Vs
Is used to set the wheel cylinder pressure control mode, and is calculated by multiplying the estimated vehicle speed V _SO by a value obtained by subtracting a preset slip ratio S from 1.

Next, S8 is executed, and the control mode of the wheel cylinder pressure is set according to the control mode setting routine shown in FIG. The setting of this control mode is 4
This is done separately for each of the rings. First, in S101, it is determined whether the wheel speed Vw is lower than the control reference wheel speed Vs. If the wheel speed Vw is equal to or higher than the control reference wheel speed Vs, the determination result in S101 becomes NO and S108 is executed, and the slow pressure increasing mode setting flag 102
It is determined whether or not is set. The gradual pressure increase mode setting flag 102 is reset in the initial setting of S1. At first, the determination result of S108 is NO, S114 is executed, and the control mode is set to the pressure increase mode. Once stored, execution of the routine returns to the main routine.

If the wheel speed Vw is lower than the control reference wheel speed Vs, the determination result in S101 becomes YES and S10
2 is executed, and the slow pressure increase mode setting flag 102 is set. Next, S103 is executed, and the wheel deceleration V
It is determined whether w 'is greater than the set deceleration Gs. If the wheel deceleration Vw 'is larger than the set deceleration Gs, after the hysteresis H is set in S104, S
At 105, the control mode is set to the depressurization mode and stored in the control mode memory 96, the flag 100 is set to indicate that the antilock control has been started, and the counter 98 is reset. The counter 98 will be described later. Note that the hysteresis H is a positive value, and that the hysteresis H is set means that the hysteresis H is determined from the set deceleration Gs.
To reduce the set deceleration Gs.

If the hysteresis H is set in S104, the next time S103 is executed, the wheel deceleration Vw 'is compared with a value smaller than the set deceleration Gs before setting. Even if a slight fluctuation occurs in the wheel speed Vw due to disturbance or the like and an error occurs in the wheel deceleration Vw ', the control mode is not changed.

When the wheel speed Vw is lower than the control reference wheel speed Vs, the wheel deceleration Vw 'is equal to or lower than the set deceleration Gs, or when the wheel deceleration Vw' becomes equal to or lower than the set deceleration Gs due to pressure reduction. Means that the determination result in S103 is NO. In this case, after the hysteresis H is reset in S106, the control mode is set to the holding mode in S107, the antilock control in-progress flag 100 is set, and the counter 98 is reset. The antilock control may be started from the holding mode. At this time, the start of the antilock control is stored by setting the antilock control in-progress flag 100 in S107.

If the wheel speed Vw is equal to or higher than the reference wheel speed Vs after the start of the antilock control, the determination result of S101 is N
When it becomes O, the judgment result of S108 becomes YES,
After S109 is executed and the hysteresis H is reset, it is determined in S110 whether the slow pressure increase mode has continued for a predetermined time or more.

[0060] execution time of gradual increase mode is measured by the counter 98, the determination of S110, the count value C of the counter 98 is performed by whether or not the set value C _A or more. Set value C _A is the value obtained by dividing the execution time of one cycle of the routine to be executed a slow increase mode time. The counter 98 is reset in the initial setting of S1, and initially, the determination result of S110 becomes NO and S111
Is executed and the count value C of the counter 98 is incremented by one, and then the control mode is set to the slow pressure increase mode in S112 and stored in the control mode memory 96.

Steps S101 and S108 to S112 are repeatedly executed until the slow pressure increase mode is continuously set for a predetermined time or longer. During this time, the wheel speed Vw is equal to the reference wheel speed Vs
If it becomes lower, the pressure is reduced or held, and S10
5, In step S107, the counter 98 is reset.

On the other hand, if the gradual pressure increase is continued for a predetermined time, the determination result in S110 becomes YES, and S113
After the slow pressure increase mode setting flag 102 and the counter 98 are reset in step S114, the control mode is set to the pressure increase mode in step S114. The wheel cylinder pressure is controlled as much as possible by reducing, holding, and increasing the pressure as little as possible, so that even if the pressure is slowly increased for a predetermined time, the pressure is increased only when the wheel cylinder pressure is insufficient. It is.

When the control mode is set as described above, step S9 in FIG. 4 is executed, and the control mode is changed according to the control mode change routine shown in FIG. First, in S201, the vehicle body deceleration V _SO ′ is set to the set value Gk.
(For example, −8 m / S ² ) or more, that is, whether the friction coefficient of the road surface is large is determined. This is because, during the antilock control, the friction coefficient of the road surface and the vehicle body deceleration correspond and increase in proportion. If the vehicle body deceleration V _SO is smaller than the set value Gk, the road surface friction coefficient is small, the determination result in S201 becomes NO, and the execution of the routine returns to the main routine.

The coefficient of road surface friction is large, and the vehicle body deceleration V _SO '
Is greater than or equal to the set value Gk, the determination result of S201 is YES.
S202 is executed, and it is determined whether the control mode set for the wheel cylinder pressure of the right rear wheel 22 is the pressure reduction mode. If not in decompression mode, S
The determination result at 202 is NO, and S205 is executed,
It is determined whether or not the control mode set for the wheel cylinder pressure of the left rear wheel 36 is the pressure reduction mode.
If the mode is not the pressure reduction mode, the determination result in S205 is NO, and the execution of the routine returns to the main routine.

If the control mode set for the wheel cylinder pressure of the right rear wheel 22 is the pressure reduction mode, the determination result in S202 is YES, and in S203, the left front wheel 16
It is determined whether or not the control mode set for the wheel cylinder pressure is the slow pressure increase mode or the pressure increase mode. If the control mode is the pressure reduction mode or the holding mode, the control mode is not changed, and the wheel cylinder pressure is reduced or held as it is. This is because, when the wheel cylinder pressure is reduced or maintained, the vehicle body deceleration may decrease, but not increase, as it is.

On the other hand, if the control mode of the wheel cylinder pressure of the left front wheel 16 is the gradual pressure increase mode or the pressure increase mode, the result of the determination in S203 becomes YES, and the flow goes to S204.
Is executed, and the control mode set for the wheel cylinder pressure of the left front wheel 16 is changed to the holding mode. The content of the control mode memory 96 set for the wheel cylinder 18 is changed to the holding mode.

When the control mode set for the wheel cylinder pressure of the left rear wheel 36 is the pressure reduction mode, and the control mode set for the wheel cylinder pressure of the right front wheel 30 is the slow pressure increase mode or the rapid pressure increase mode. In addition, the determination result in S206 becomes YES, and S207 is executed to change the control mode of the right front wheel 36 to the holding mode.

When the control mode is changed in this manner, S10 of the main routine is executed, and the first and second control systems provided for each system of the four wheels according to the control modes set for the four wheel cylinders, respectively. A control signal for opening and closing the second solenoid on-off valves 50 and 56 is output to each of them, and the wheel cylinder pressure is controlled in a set control mode.

In this embodiment, when the anti-lock control is performed on the front wheels when the front wheel wheel cylinder pressure is changed from the pressure increasing mode or the gradual pressure increasing mode to the holding mode, the mode is not changed. Since the chances of increasing the pressure are reduced as compared with the above, the wheel cylinder pressure once reduced is difficult to recover, and the wheel cylinder pressure is controlled to be lower on average. When the anti-lock control is not performed on the front wheel, the wheel cylinder pressure of the front wheel is maintained while the wheel cylinder pressure of the rear wheel is reduced, and the wheel cylinder pressure of the rear wheel is increased, maintained, or reduced. While the pressure is gradually increased, the wheel cylinder pressure of the front wheels is increased, so that the pressure increase gradient is smaller than when the mode is not changed.

As described above, when the vehicle deceleration is equal to or greater than the set value and the control mode of the wheel cylinder pressure of the left and right rear wheels 36 and 22 is the pressure reduction mode, the wheel cylinder pressure of the front wheel at the diagonal position is reduced. When the control mode is the gradual pressure increase mode or the pressure increase mode, these are changed to the hold mode, so that the increase in the front wheel braking force is suppressed, the posture of the vehicle body diagonally falling forward is reduced, and the rear wheel ground load is reduced. Reduction is suppressed and running stability is improved.

As is clear from the above description, in this embodiment, the first and second solenoid valves 50 and 56 provided in the left front wheel system constitute a left front wheel hydraulic pressure control device, and the right front wheel The first and second solenoid on-off valves 50 and 56 provided on the system constitute a right front wheel hydraulic pressure control device, and the first and second solenoid on-off valves 50 and 56 provided on the left rear wheel system comprise a left rear wheel. The first and second solenoid valves 50 and 56 provided in the right rear wheel system constitute a right rear wheel hydraulic pressure control device. In the present embodiment, the solenoid valve device constituted by the first and second solenoid on-off valves 50 and 56 constitutes a hydraulic control device, and the anti-lock control device comprises a master cylinder (hydraulic pressure source) and a reservoir. Solenoid valve device provided between the wheel cylinder and the wheel cylinder for increasing, holding and decreasing the hydraulic pressure of the wheel cylinder, and anti-lock control means for controlling the switching of the solenoid valve device to keep the wheel slip ratio in an appropriate range And a recirculation type anti-lock control device in which the brake fluid discharged from the wheel cylinder to the reservoir is returned to the master cylinder.

Further, S1 to S of the computer ROM
8 and CPU for storing S10 to S12 and CPU
Of these steps constitute an antilock control means, a part for storing S9 of the ROM, and a CP.
The part of U that executes S9 constitutes a front wheel cylinder pressure holding means when the rear wheel cylinder pressure decreases as a wheel cylinder pressure suppressing means. This embodiment is an example of the aspect (4). The front wheel cylinder pressure holding means when the rear wheel cylinder pressure decreases can be considered as rising gradient suppressing means for suppressing a rising gradient of the wheel cylinder pressure of the front wheels. In this embodiment, the vehicle speed is estimated based on the wheel speed and the wheel deceleration, and the vehicle deceleration is obtained. The rotation speed sensors 82 to 88 and the rotation speed sensors 82 to 88 of the computer are used. The calculation of the wheel speed, the estimation of the vehicle speed, and the calculation of the vehicle deceleration based on the detection results of the above constitute the vehicle deceleration related amount acquisition means.

The vehicle body deceleration can be obtained by detecting a vehicle speed by providing a Doppler type ground vehicle speed sensor in addition to calculating the vehicle speed based on the wheel speed. Alternatively, the vehicle deceleration can be calculated based on the master cylinder pressure or the wheel cylinder pressure. It can also be obtained indirectly based on this In a vehicle without an anti-lock control device or a proportioning valve, or with at least one of these devices but not operating, the master cylinder pressure and body deceleration are usually in a proportional relationship. is there. When at least one of the anti-lock control device and the proportioning valve is activated, the weighted average value of the wheel cylinder pressures of all the wheels (the wheel cylinder pressures of the front wheel brake and the rear wheel brake are the same). However, since the braking force generated is usually different, it is necessary to calculate the average value by changing the weight between the wheel cylinder pressure of the front wheel and the wheel cylinder pressure of the rear wheel.) It is in. Therefore, if the master cylinder pressure or the wheel cylinder pressure is known, the vehicle deceleration can be known. In this case, a pressure detecting device that detects the master cylinder pressure or the wheel cylinder pressure, which is the vehicle deceleration related amount related to the vehicle deceleration, is used. It is a vehicle deceleration related amount acquisition means.

Another embodiment of the present invention is shown in FIGS. In this embodiment, when the anti-lock control is performed on the rear wheels in a state where the vehicle body deceleration is equal to or greater than the set value, the reference wheel speed at the time of the anti-lock control is set for the front wheels diagonally positioned with respect to the rear wheels. The slip rate of
Anti-lock control is easily started for the front wheels, and
By making it easier to hold or reduce the pressure, the wheel cylinder pressure is reduced to reduce the front wheel contact load, and the rear wheel contact load is increased to improve running stability. This example describes the method described in the above (9).
It is an example of a braking force control device .

The hydraulic brake device with the antilock control device having the braking force control device of the present embodiment is constructed in the same manner as the above embodiment, and the antilock control unit 80 includes a main routine shown in FIG. A control mode setting routine shown in FIG. 5 and a front wheel anti-lock control slip ratio changing routine shown in FIG. 7 are stored.

S301 to S306 of the main routine are executed in the same manner as S1 to S6. When the estimated vehicle speed V _SO is larger than the set value, a front wheel anti-lock control slip ratio change routine shown in FIG. 7 is executed in S307. In this change routine, first,
In S401, it is determined whether or not the vehicle body deceleration V _SO 'is equal to or greater than the set value Gk. Becomes NO and S40
At 6, the slip rate is returned to the standard slip rate, and the execution of the routine returns to the main routine. If the slip rate is the standard slip rate, it is left as it is.

If the vehicle deceleration V _SO 'is equal to or greater than the set value Gk, the determination result in S401 is YES, and in S402, it is determined whether the anti-lock control has been started for the right rear wheel 22 or not. This determination is made based on whether or not the anti-lock control flag 100 provided for the right rear wheel 22 is set. If the anti-lock control is not performed on the right rear wheel 22, the determination result in S402 is NO, and it is determined in S404 whether the anti-lock control is performed on the left rear wheel 36. This determination is made based on whether or not the anti-lock control flag 100 provided for the left rear wheel 36 has been set. If the anti-lock control has not been performed, the determination result in S404 is also NO, and the routine is executed. Returns to the main routine. When the anti-lock control is not performed on the rear wheels, the slip ratio cannot be reduced.

As described above, when the anti-lock control is not performed for the rear wheels and the slip ratio cannot be reduced, the next time the control reference wheel speed is set in S308 of the main routine, the preset 4 A standard slip ratio common to the wheels is used, and in S309, the control mode is set based on the control reference wheel speed set by the slip ratio. This standard slip ratio is stored in the RAM in the initial setting.

If the anti-lock control has been performed on the right rear wheel 22, the determination result in S402 becomes YES, and S4
03 is executed, and the slip ratio for antilock control of the left front wheel 16 is changed to a front wheel cylinder pressure suppression slip ratio smaller than the standard slip ratio. Therefore,
The control reference wheel speed set in S308 increases, and the anti-lock control for the left front wheel 16 is easily started, and the decompression and holding are easily performed. If the anti-lock control has been performed on the left rear wheel 36, the anti-lock control slip ratio of the right front wheel 30 is changed to the front wheel cylinder pressure suppression slip ratio in S405.

Note that the front wheel cylinder pressure suppression slip ratio is returned to the standard slip ratio in S311 of the main routine at the end of the diagonally located rear wheel antilock control. Such a change in the anti-lock control slip ratio is executed even after the anti-lock control is started for the front wheels, if the vehicle body deceleration is large and the anti-lock control is started for the rear wheels. .

In this embodiment, the computer RO
The part that stores S307 of M and the part that executes S307 of the CPU are anti-lock control front wheel slip ratio changing means as one type of front wheel anti-lock control reference value changing means that is one mode of the front wheel cylinder pressure suppressing means. The wheel cylinder pressure of the front wheel is suppressed in association with the anti-lock control of the rear wheel at the diagonal position, reducing the diagonal front lowering posture of the vehicle body and running stability at the time of running on a stride road. An improvement effect and the like can be obtained.

In this embodiment, the control reference wheel speed at the time of anti-lock control of the front wheels is set by multiplying the estimated vehicle speed by a value obtained by subtracting the slip ratio S from 1 to reduce the setting slip ratio. Although the wheel cylinder pressure is reduced by doing so, the control reference wheel speed can be set using the slip amount. The control reference wheel speed is set by subtracting a constant value that is the slip amount from the vehicle speed, and the constant value subtracted from the vehicle speed may be reduced. In this case, the anti-lock control front wheel slip amount changing means for performing this is the front wheel anti-lock control reference value changing means and the front wheel cylinder pressure suppressing means.

The slip ratio and the slip amount when setting the control reference wheel speed may be changed according to the road surface friction coefficient. As the road surface friction coefficient increases, the control reference wheel speed is changed to a value at which anti-lock control is performed with a small slip ratio and slip amount of the front wheels. This is described in (10).
It is an example of a braking force control device .

FIGS. 8 and 9 show still another embodiment of the present invention .
Shown in In this embodiment, when the anti-lock control is performed on the rear wheels in a state where the vehicle body deceleration is high, the anti-lock control is performed on the front wheels in the same control mode as the rear wheels. This embodiment is an example of the braking force control device according to the above mode (8) . The control mode setting in S508 of the main routine shown in FIG. 8 is performed as follows in accordance with the control mode setting routine shown in FIG.

In the control mode setting routine, first,
In S601, it is determined whether or not the vehicle deceleration V _SO ′ is equal to or greater than the set value Gk.
The result of the determination in 601 is YES, and a determination is made in S602 as to whether or not antilock control is being performed on the right rear wheel 22. If the antilock control has not been performed, the determination result in S602 is NO, and S604 is executed, and the control mode of the wheel cylinder pressure of the left front wheel 16 is set according to a routine similar to the control mode setting routine shown in FIG. You. If the anti-lock control has been performed on the right rear wheel 22, the determination result in S602 is YES.
In S603, the control mode of the wheel cylinder pressure of the left front wheel 16 is set to the same mode as the control mode of the right rear wheel 22.

Next, S605 to S6 for the right front wheel 30
08 is executed in the same manner as S601 to S604, and the left rear wheel 3
If the anti-lock control is performed for No. 6, the control mode is set to the same mode as the control mode of the wheel cylinder pressure of the left rear wheel 36. If the control mode of the wheel cylinder pressure is set for the left and right front wheels 16 and 30 as described above,
In S609 and S610, the control mode of the wheel cylinder pressure of the left and right rear wheels 36, 22 is set according to the same routine as the control mode setting routine shown in FIG.

Even if the anti-lock control is performed for the front wheels, if the anti-lock control is performed for the rear wheels in a state where the vehicle deceleration is high, the anti-lock control is performed like the rear wheels. Is performed. Therefore, when the anti-lock control is not performed on the front wheels, the wheel cylinder pressure is reduced, and the front wheel ground load is reduced. Of course, even when the anti-lock control is performed on the front wheels, the ground load is small. The anti-lock control is performed in accordance with the rear wheels that are likely to slip, so that the wheel cylinder pressure is suppressed to be lower than when the front wheels are controlled according to the slip condition (slip rate, slip amount, etc.), and the rear wheel contact load is reduced. Is avoided and running stability is improved.

Also in the present embodiment, the wheel cylinder pressure of the front wheels is controlled in association with the antilock control of the rear wheels located at the diagonal positions, so that the above-described obliquely forward-lowering body posture correction is performed. In addition, effects such as improvement of running stability at the time of running on a stride road can be obtained. Computer ROM
The parts storing S602, S603, S606, and S607 and the part of the CPU that executes those steps constitute the rear wheel following front wheel cylinder pressure suppressing means.

FIG. 10 shows still another embodiment of the present invention .
In the present embodiment, when the anti-lock control is started for the rear wheels, if the anti-lock control is not performed for the front wheels, the wheel cylinder pressure is maintained and the increase in the front-wheel contact load is suppressed. . This embodiment is described above.
It is an example of the mode described in the paragraph (7) .

In the present embodiment, the main routine is executed as shown in FIG.
The control mode setting in S508 is performed according to the control mode setting routine shown in FIG. In this control mode setting routine, first, in S701, it is determined whether or not the vehicle body deceleration V _SO 'is equal to or greater than the set value Gk. If it is smaller than the set value Gk, the determination result of S701 is NO, and
At 4, the control mode of the left front wheel 16 is set by executing the same routine as the control mode setting routine shown in FIG.

If the vehicle deceleration V _SO ′ is equal to or greater than the set value Gk, the determination result in S701 is YES, and in S702, it is determined whether the left front wheel 16 is under the antilock control. If the anti-lock control is being performed, the determination result in S702 is YES, and S704 is executed. If the anti-lock control is not being performed, the determination result in S702 is NO, and in S703, it is determined whether the right rear wheel 22 is under the anti-lock control. If the anti-lock control is not being performed, S704 is executed. If the anti-lock control is being performed, S705 is executed, and the control mode of the wheel cylinder pressure of the left front wheel 16 is set to the holding mode. Right front wheel 3
0 in steps S706 to S710.
The control mode is set in the same manner as described above.
The control modes of the control modes 6 and 22 are set in S711 and S712 by executing the same control mode setting routine shown in FIG.

When the front wheel anti-lock control is started before the rear wheel anti-lock control, the wheel cylinder pressure is not maintained even when the rear wheel anti-lock control is started, and the control is performed in accordance with the front wheel slip ratio. Is done. The vehicle of the present embodiment is also usually designed so that the anti-lock control is required first for the rear wheels, and the anti-lock control is required first for the front wheels when some special circumstances occur. In such a case, the vehicle deceleration should hardly exceed the predetermined value, but if such a situation occurs, the anti-lock control is continued rather than maintaining the wheel cylinder pressure of the front wheels. This is done because it is thought that the person who put it can follow it smoothly when the special circumstances are resolved.

In this embodiment, the computer RO
The part of M that stores S701 to S710 and the part of the CPU that executes those steps constitute front wheel cylinder pressure holding means at the start of rear wheel anti-lock, and the wheel cylinder pressure of the front wheel is set at the diagonally opposite position of the rear wheel. The anti-lock control is controlled in association with the above, and the effects such as the above-described correction of the diagonally forward lowering posture and the improvement of the running stability at the time of running on a straddle road are obtained.

In each of the above embodiments, the case where the left and right front wheels and the rear wheels are independently subjected to antilock control has been described as an example. However, in the present invention, items (1) to (12)
As shown in FIG. 11, the present invention can also be applied to a braking force control device of a hydraulic brake device in which common antilock control is performed on the left and right rear wheels.

The hydraulic brake device is a front-rear two-system hydraulic brake device. Therefore, the brake pedal 11
The hydraulic pressure generated in one of the pressurizing chambers of the master cylinder 112 by the depression of 0 is transmitted to the front wheel cylinders 122, 124 of the brakes of the left and right front wheels 118, 120 through the liquid passages 114, 116. The hydraulic pressure generated in the other pressurizing chamber of the master cylinder 112 is transmitted to the rear wheel cylinders 132, 134 of the respective brakes of the left and right rear wheels 128, 130 via the proportioning valve 136 by the liquid passage 126. .

Each of the liquid passages 114, 116 and 126 is provided with an anti-lock actuator to control the wheel cylinder pressure. The configuration of each of these antilock actuators is the same, and is the same as that of the embodiment shown in FIGS. 1 to 5.

The antilock control unit 140 that controls the opening and closing of the first and second solenoid on-off valves 50 and 56 and the pump motor 68 detects the rotational speeds of the left and right front wheels 118 and 120 and the rear wheels 128 and 130. The detection results of the rotation speed sensors 142, 144, 146, and 148 and the detection signal of the brake switch 150 are supplied.

The ROM of the computer of the antilock control unit 140 stores a main routine shown in FIG. 12, a control mode change routine and a control mode setting routine similar to those of the embodiment shown in FIGS. 1, 3 to 5. I have. S801 to S809 of the main routine are executed similarly to S1 to S9 of the main routine shown in FIG. The left and right rear wheels 128 and 130 are commonly subjected to antilock control, but the control mode is once set independently according to the respective speeds, and thereafter the control modes are shared.

Therefore, the change of the control mode in S809 is performed based on the control mode set for each wheel cylinder pressure of the left and right rear wheels 128, 130. After the change of the control mode, in S810, the control modes of the wheel cylinder pressures of the left and right rear wheels 128 and 130 are shared. In this embodiment, when the control modes set for the rear wheel cylinder pressures are different from each other, the low select control is executed in which the control mode is made to coincide with the mode in which the wheel cylinder pressure is kept low. For example, when one control mode is the pressure reduction mode and the other control mode is the holding mode, both control modes are set to the pressure reduction mode.

Then, in S811, the left and right front wheels 1
18, 120 front wheel cylinders 122, 1
24, control signals are output to the first and second solenoid valves 50, 56 provided in the liquid passages 114, 116, respectively, to execute the control mode set in S808, and the left and right rear wheels 128, 130 For each of the rear wheel cylinders 132, 134, a control signal is output to the first and second solenoid on-off valves 50, 56 provided in the liquid passage 126 in order to execute the common control mode in S810.

As described above, if the control mode is shared with the control mode for suppressing the wheel cylinder pressure, the structure of the hydraulic brake device is simplified, and the slip of both the right and left rear wheels 128 and 130 is reduced. The rate can be prevented from becoming excessive. Also in the present embodiment, the wheel cylinder pressure of the front wheels is controlled in association with the anti-lock control of the rear wheels located at the diagonal positions. An effect such as improvement in running stability during running is obtained.

Another embodiment of the present invention is shown in FIGS. In the present embodiment, when the anti-lock control is performed on the rear wheels, the road surface friction coefficient is estimated, and the set value of the vehicle body deceleration for starting the suppression of the wheel cylinder pressure is changed based on the estimated friction coefficient. Yes, as described in paragraph (11)
It is an example of the like.

The hydraulic brake device with an antilock control device having the braking force control device of this embodiment is constructed in the same manner as the hydraulic brake device shown in FIGS. 13 stores a main routine shown in FIG. 13, a vehicle deceleration set value changing routine shown in FIG. 14, and a control mode setting routine shown in FIG.

S901 to S907 of the main routine are executed in the same manner as S1 to S7. After the control reference wheel speed is set in S907, in S908 FIG.
The setting value of the vehicle body deceleration based on the road surface friction coefficient is changed according to the routine shown in FIG. In the vehicle body deceleration setting value change routine, first, in S1001, it is determined whether or not antilock control is being performed on any of the rear wheels. If anti-lock control is not performed,
This is because a road surface friction coefficient cannot be obtained.

If the antilock control has not been performed, S
The determination result at 1001 is NO, and the execution of the routine returns to the main routine. If the antilock control is being performed, the determination result in S1001 is YES, and S1002 is executed, and the road surface friction coefficient is estimated from the vehicle body deceleration V _so '. As long as the road surface friction coefficient is uniform, the anti-lock control of the rear wheels is started before the anti-lock control of the front wheels, and the vehicle deceleration V when the anti-lock control of the rear wheels is being performed. _The larger the value of _so ', the greater the coefficient of road friction. Therefore, in S1003, the set value Gk for determining whether to suppress the front wheel cylinder pressure is changed to a value proportional to the road surface friction coefficient. The set value Gk is initially set to a standard value corresponding to a dry asphalt road, and the set value is changed to a value corresponding to the road surface friction coefficient.

The determination in S1001 is made as to whether or not the anti-lock control is performed for both the left and right rear wheels, and the determination is made only when the result of this determination is YES.
It is also possible to perform the estimation of the road surface friction coefficient of 1002. In this case, the anti-lock control is started only on one of the rear wheels because there is a portion where the friction coefficient is locally low on the road surface. In this case, an erroneous estimation of the road surface friction coefficient can be avoided.

If the set value Gk is changed, S909 is executed, and the control mode is set according to the control mode setting routine shown in FIG. First, in S1101, it is determined whether or not at least one of the left and right rear wheels is under antilock control. If neither is under the antilock control, the determination result of S1101 is NO,
Steps S1102 to S1105 are executed, and the control modes for the left and right front wheels and the rear wheels are set according to the same routine as the control mode setting routine shown in FIG.

If any one of the left and right rear wheels is under the antilock control, the determination result in S1101 is YES, and in S1106, it is determined whether at least one of the left and right front wheels is under the antilock control. If any one of them is under the antilock control, the determination result of S1106 becomes YES, and S1102 to S1105 are executed. If the anti-lock control is not being performed on any of the left and right front wheels, the determination result of S1106 is NO, and
Step 1107 is executed to determine whether or not the holding mode setting flag is set. The holding mode setting flag is provided in the RAM of the computer along with the anti-lock control flag and the like, and is reset in the initial setting. Therefore, the determination result in S1107 is NO.

Next, S1108 is executed to determine whether or not the vehicle body deceleration V _SO 'is equal to or greater than the set value Gk. If the vehicle body deceleration V _SO ′ is smaller than the set value Gk, S1
The determination result at 108 is NO, and the wheel cylinder pressure is not held. If the vehicle body deceleration V _SO 'is equal to or greater than the set value Gk, the determination result in S1108 becomes YES, and
9, the control of the wheel cylinder pressures of the left and right front wheels is set to the holding mode, and the holding mode setting flag is set. Therefore, once the holding mode is set, steps S1101, S1106, S1107 and S11 are performed until the anti-lock control of the rear wheels is released.
09 is repeatedly executed, and the wheel cylinder pressure is maintained. The holding mode setting flag is reset in S911 of the main routine by releasing the rear wheel antilock control.

In the control mode of the wheel cylinder pressures of the left and right front wheels, after the vehicle body deceleration V _SO ′ is equal to or higher than the set value Gk and the holding mode is set, the vehicle body deceleration V _SO ′ is set to the set value G _SO.
If it is smaller than k, it may be set in S1102 and S1103 according to the control mode setting routine shown in FIG. In this case, the holding mode setting flag is unnecessary, so that step S1107 is omitted and step S1109 is performed.
The setting of the holding mode setting flag in step S11 is stopped.
Subsequent to the determination at 06, the determination at S1108 may be made.

As described above, the set value Gk to be compared with the vehicle body deceleration V _SO 'to determine whether to maintain the wheel cylinder pressure is set according to the road surface friction coefficient.
As the road surface friction coefficient increases, the wheel cylinder pressure is maintained at a higher value, and traveling stability can be obtained while suppressing the sacrifice of the braking force. In S1109, it is also possible to hold only the wheel cylinder pressure of the front wheel at the diagonal position while the anti-lock control is being performed among the left and right rear wheels. The effect of correcting the vehicle body posture lowered diagonally forward and improving the running stability when traveling on a stride road can be obtained.

In this embodiment, the computer RO
The part that stores S908 of M and the part that executes S908 of the CPU constitute the road surface friction coefficient-corresponding front wheel cylinder pressure suppression start timing changing means as the road friction coefficient-corresponding vehicle deceleration set value changing means.
1, a part storing S1106 to S1109 and CP
The portion of U that performs those steps constitutes front wheel cylinder pressure suppression means.

The vehicle deceleration V during the antilock control is
_The road surface friction coefficient is estimated based on _SO ′, and the vehicle deceleration V is determined based on the detection results of the rotation speed sensors 82 to 88 and the rotation speed sensors 82 to 88 of the CPU.
_The portion for calculating _SO ′ constitutes a road friction coefficient related amount acquiring means.

In each of the embodiments shown in FIGS. 1 to 12, the set value for judging the magnitude of the vehicle body deceleration may be changed according to the road surface friction coefficient.

The set value for judging the magnitude of the vehicle body deceleration, that is, the set value Gk to be compared with the vehicle body deceleration V _SO 'to determine whether or not to suppress the wheel cylinder pressure, is the gradient of the road surface or the vehicle. It may be changed according to the loading weight. A road gradient detecting means for detecting the gradient of the road surface is provided, and the set value Gk is increased as the gradient increases and the gradient is increased, so that the wheel cylinder pressure of the front wheels is maintained at a high value. Further, a load detecting means for detecting the load of the vehicle is provided, and the larger the load, the larger the set value Gk, so that the wheel cylinder pressure of the front wheels is maintained at a high value. When the road surface is uphill, or when the weight of the vehicle is large, the rear wheel contact load is large and lateral force can be obtained on the rear wheel.Therefore, the wheel cylinder pressure of the front wheel is increased to increase the vehicle deceleration. This is because running stability can be ensured, and running stability can be improved while sacrifice of braking force is kept small.

Further, in each of the embodiments shown in FIGS. 1 to 12, the front wheels and the rear wheels located on the diagonal line of the vehicle are controlled in association with each other, but this is not essential. For example, the front and rear wheels located on the same left and right sides of the vehicle may be controlled in association with each other, or both of the left and right front wheels may be used when pressure reduction or antilock control is performed on one of the left and right rear wheels. The cylinder pressure may be suppressed.

Further, the antilock control device of each of the above embodiments is a recirculation type antilock control device using the master cylinder as a hydraulic pressure source. Pump and accumulator, or antilock control device composed of pump,
An antilock control device including a three-position electromagnetic directional control valve in which a solenoid valve device is switched between three states, a pressure increasing state, a holding state, and a pressure reducing state, and two states of a pressure increasing state and a pressure reducing state of the solenoid valve apparatus. An anti-lock control device comprising a two-position electromagnetic directional control valve which is switched to a solenoid valve device, wherein the electromagnetic valve device switches the wheel cylinder pressure between an increased pressure state and a reduced pressure state by a combination of opening and closing of two electromagnetic on-off valves. It is also applicable to a braking force control device such as an antilock control device, an antilock control device in which the solenoid valve device is a spool type electromagnetic proportional control valve, and a hydraulic brake device having a positive displacement antilock control device. it can.

The positive displacement type antilock control device is provided with shutoff means such as an electromagnetic opening / closing valve for shutting off the wheel cylinder from the master cylinder during the antilock control, and reduces the volume of the variable volume chamber provided on the wheel cylinder side from the shutoff means. The wheel cylinder pressure is controlled by changing it. In the positive displacement antilock control device, the variable volume chamber and the volume changing means for changing the volume of the variable volume chamber constitute a hydraulic pressure control device. As the volume changing means, a piston constituting the movable wall of the variable volume chamber is used. May be moved by an electric motor, or may be controlled by an electromagnetic valve device to control the hydraulic pressure of a control hydraulic chamber formed on the opposite side of the variable volume chamber with a piston interposed therebetween.

FIGS. 16 and 17 show another embodiment of the present invention .
Shown in The hydraulic brake device according to the present embodiment does not include an antilock control device, and is an example of the braking force control device according to the above mode (5). As shown in FIG. 16, hydraulic pressure is generated in each of two pressurizing chambers of the master cylinder 162 by depressing a brake pedal 160 as a brake operating member. The hydraulic pressure generated in one of the pressurizing chambers is transmitted to the front wheel cylinders 170 and 172 of the brakes of the left and right front wheels 166 and 168 by the liquid passage 164, and the hydraulic pressure generated in the other pressurizing chamber is changed to the left and right by the liquid passage 174. The power is transmitted to the rear wheel cylinders 180, 182 of the brakes of the wheels 176, 178.

The normally open electromagnetic on-off valve 1 is located on the part closer to the master cylinder 162 than the two branches of the liquid passage 164.
86 are provided. The liquid passage 164 is also provided with a bypass passage 188 that bypasses the electromagnetic on-off valve 186, and the bypass passage 188 is connected to the master cylinder 16 from the front wheel cylinder 170, 172 side.
A check valve 190 is provided to allow the flow of the brake fluid to the second side but prevent the flow in the opposite direction.

The opening and closing of the electromagnetic on-off valve 186 is controlled by a control unit 196 mainly composed of a computer.
The control unit 196 is supplied with the detection signals of the rotation speed sensors 192, 194, 198, 200 for detecting the respective rotation speeds of the four wheels.
Calculate wheel deceleration, vehicle speed, vehicle deceleration, and the like.
The ROM of the computer stores a front wheel cylinder pressure suppression routine shown by a flowchart in FIG.

The front wheel cylinder pressure suppression routine is executed simultaneously with turning on the power. S12 of this routine
01 to S1204 are executed in the same manner as S1 to S4,
Wheel speed Vw, wheel deceleration Vw ', estimated vehicle speed _VSO ,
After calculating the vehicle body deceleration V _SO ′, S1205 is executed, and it is determined whether or not the vehicle body deceleration V _SO ′ is equal to or greater than the set value Gk. If the vehicle body deceleration V _SO ′ is smaller than the set value Gk, the determination result of S1205 is NO, and
7, a signal for opening the electromagnetic on-off valve 186 is output.
When the vehicle deceleration is low, there is no possibility that the rear-wheel ground contact load becomes excessively small. Therefore, it is not necessary to suppress an increase in the wheel cylinder pressure of the left and right front wheels 166 and 168, and the electromagnetic on-off valve 186 is kept open. It is done.

On the other hand, the vehicle deceleration V _SO ′ is equal to the set value G.
If it is equal to or greater than k, the determination result in S1205 is YES,
In S1206, a command signal for switching the electromagnetic on-off valve 186 to the closed state is output. Thus, transmission of hydraulic pressure from master cylinder 162 to front wheel cylinders 170 and 172 is interrupted, and an increase in wheel cylinder pressure is suppressed, and a decrease in rear wheel contact load is suppressed.

When the brake pedal 160 is loosened after the solenoid valve 186 is closed, the hydraulic pressure on the master cylinder 162 decreases, and the brake fluid is stopped from the front wheel cylinders 170 and 172. After returning to the master cylinder 162 through the valve 190, the wheel cylinder pressure decreases. If the vehicle body deceleration V _SO ′ thereby decreases, the determination result in S1205 becomes NO, and S1207 is executed to open the electromagnetic on-off valve 186.

In this embodiment, the solenoid on-off valve 186,
A portion of the computer ROM that stores S1201 to S1207 and a portion of the CPU that executes those steps constitute a front wheel cylinder pressure suppression unit. A control unit 196 including the front wheel cylinder pressure suppression unit, a rotation speed sensor 192 , 194, 1
98, 200, check valve 190, etc.
A braking force control device is configured together with a brake mainly composed of 0, 172, 176 and 178.

The front wheel cylinder pressure suppressing means of this embodiment can be applied to the embodiments shown in FIGS. It is necessary to provide a solenoid valve 186, a bypass passage 188 and a check valve 190 in the liquid passage connecting the master cylinder and the front wheel cylinder separately from the hydraulic control device for anti-lock control to suppress the front wheel cylinder pressure. Is generated, the control unit 196 closes the solenoid on-off valve 186. If the only condition for suppressing the front wheel cylinder pressure is that the vehicle body deceleration exceeds the set value, a mechanical G valve, that is, a mechanical G valve, instead of the electromagnetic on-off valve 186 and the control unit 196,
When the vehicle deceleration becomes equal to or more than the set value, a control valve that shuts off the front wheel cylinder from the master cylinder can be used by closing the valve hole by the ball as the inertial mass climbing the slope and closing the valve hole.

In the above-described embodiment, the shutoff means for shutting off the front wheel cylinder from the master cylinder when it becomes necessary to suppress the front wheel cylinder pressure is provided. May be provided as rising gradient limiting means for limiting the rising gradient of the front wheel cylinder pressure when it becomes necessary to suppress the front wheel cylinder pressure.

The road surface friction coefficient can be obtained based on the behavior of the wheels. For example, as described in the specification of Japanese Patent Application No. 5-242630 filed by the present applicant (especially the invention described in claim 2), the wheels are divided into a belt side and a rim side in a tire. Considering a model in which the inertial mass on the belt side and the inertial mass on the rim side are connected by a torsion spring, the behavior of this model is acquired using a disturbance observer, and the friction coefficient of the road surface is detected. In this case, the means for acquiring the behavior of the wheels constitutes the road friction coefficient related quantity acquiring means. When the road surface friction coefficient is obtained based on the behavior of the wheels, it is possible to acquire the road surface friction coefficient without performing the antilock control. In the embodiment shown in FIGS. The set value Gk for determining whether or not the speed is high can be changed based on the road surface friction coefficient.

Further, the road surface may be irradiated with ultrasonic waves, light, or the like to detect the reflected wave, and the road surface friction coefficient may be obtained based on the reflectance. Even when the road surface friction coefficient is obtained based on the reflectance of ultrasonic waves and light, the road surface friction coefficient can be obtained without performing the antilock control.

Further, the present invention can be carried out in a mode in which the combination of the components in each of the above embodiments is changed. In addition, without departing from the scope of the claims, the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control mode change routine stored in a ROM of a computer of an antilock control unit for controlling a hydraulic brake device with an antilock control device having a braking force control device according to an embodiment of the present invention. It is.

FIG. 2 is a system diagram showing the hydraulic brake device.

FIG. 3 is a diagram showing a configuration of a RAM of the computer.

FIG. 4 is a flowchart showing a main routine stored in the ROM.

FIG. 5 is a flowchart showing a control mode setting routine stored in the ROM.

FIG. 6 is a flowchart showing a main routine stored in a ROM of a computer which is a component of the braking force control device according to another embodiment of the present invention .

FIG. 7 is a flowchart showing a slip ratio changing routine for front wheel anti-lock control of the main routine shown in FIG. 6;

FIG. 8 is a flowchart showing a main routine stored in a ROM of a computer which is a component of a braking force control device according to still another embodiment of the present invention .

FIG. 9 is a flowchart showing a control mode setting routine of a main routine shown in FIG. 8;

FIG. 10 is a flowchart showing a control mode setting routine stored in a ROM of a computer which is a component of a braking force control device according to still another embodiment of the present invention .

FIG. 11 is a system diagram of a hydraulic brake device with an anti-lock control device including a braking force control device according to still another embodiment of the present invention .

12 is a flowchart showing a main routine stored in a ROM of a computer of the antilock control unit of the hydraulic brake device shown in FIG.

FIG. 13 is a flowchart showing a main routine stored in a ROM of a computer which is a component of a braking force control device according to still another embodiment of the present invention.

FIG. 14 is a flowchart showing a vehicle body deceleration set value changing routine of a main routine shown in FIG. 13;

FIG. 15 is a flowchart showing a control mode setting routine of a main routine shown in FIG.

FIG. 16 is a system diagram of a hydraulic brake device including a braking force control device according to still another embodiment of the present invention.

17 is a flowchart showing a front wheel cylinder pressure suppression routine stored in a ROM of a computer, which is a component of the braking force control device shown in FIG.

[Explanation of symbols]

 Reference Signs List 16 front left wheel 18 front wheel cylinder 22 right rear wheel 24 rear wheel cylinder 30 right front wheel 32 front wheel cylinder 36 left rear wheel 38 rear wheel cylinder 50 first solenoid on-off valve 56 second solenoid on-off valve 80 anti-lock control unit 118 left front wheel 120 Right rear wheel 122,124 Front wheel cylinder 128 Left rear wheel 130 Right rear wheel 132,134 Rear wheel cylinder 140 Antilock control unit 166 Left front wheel 168 Right rear wheel 170,172 Front wheel cylinder 176 Left rear wheel 178 Right rear wheel 180,182 Rear wheel cylinder 186 Solenoid on-off valve 196 Control unit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-255468 (JP, A) JP-A-4-5155 (JP, A) JP-A-5-201317 (JP, A) JP-A-6-25517 8814 (JP, A) JP-A-60-259557 (JP, A) JP-A-1-301450 (JP, A) JP-A-4-224449 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) B60T 8/58

Claims (3)

(57) [Claims] 1. A brake for suppressing rotation of a front wheel and a rear wheel, a front wheel hydraulic pressure control device for increasing and decreasing a wheel cylinder pressure of a front wheel brake, and a wheel cylinder pressure of a rear wheel brake at least increasing. Anti-lock control means for controlling the front wheel hydraulic pressure control device and the rear wheel hydraulic pressure control device to maintain each slip of the front wheel and the rear wheel in an appropriate range; and When the vehicle deceleration increases in a state that satisfies a predetermined condition, during the time when the wheel cylinder pressure of the rear wheel is reduced by the control of the rear wheel hydraulic pressure control device by the antilock control unit, When the wheel cylinder pressure of the front wheel is in a state of being increased, the wheel cylinder of the front wheel is controlled by the front wheel hydraulic pressure control device. Brake force control apparatus which comprises a front wheel cylinder pressure suppression means for holding the pressure. 2. The front wheel hydraulic pressure control device includes a left front wheel hydraulic pressure control device and a right front wheel hydraulic pressure control device that at least independently increase and decrease the wheel cylinder pressure of each of the left and right front wheel brakes. Wherein the rear wheel hydraulic pressure control device includes a left rear wheel hydraulic pressure control device and a right rear wheel hydraulic pressure control device that at least independently increase and decrease the wheel cylinder pressure of each brake of the left and right rear wheels. ,
The anti-lock control means controls the respective hydraulic pressure control devices for the left front wheel, the right front wheel, the left rear wheel, and the right rear wheel to keep the slip of the left and right front wheels and the rear wheel in an appropriate range. The braking force control device according to claim 1. 3. A brake for restraining the rotation of the left and right front wheels and the left and right rear wheels, and a left front wheel hydraulic pressure control device and a right front wheel for at least independently increasing and decreasing the wheel cylinder pressure of each of the left and right front brakes. A hydraulic pressure control device, a hydraulic pressure control device for the left rear wheel and a hydraulic pressure control device for the right rear wheel for independently increasing and decreasing the wheel cylinder pressure of each brake of the left and right rear wheels independently, Anti-lock control means for controlling the respective hydraulic pressure control devices for the right front wheel, the left rear wheel, and the right rear wheel to keep the slip of the left and right front wheels and the rear wheels within an appropriate range, respectively, and the vehicle deceleration is predetermined. in the case of increased in satisfying state of being, after the right and left by the anti-lock control means
At least part of the time when the wheel cylinder pressure of one of the wheels is reduced , the rear wheel of the left front wheel hydraulic pressure control device and the right front wheel hydraulic pressure control device, the wheel cylinder pressure of which is reduced. A front wheel cylinder pressure suppressing means for suppressing an increase in the wheel cylinder pressure of the front wheel by controlling the one corresponding to the front wheel located on the diagonal line of the vehicle in a manner including holding and not increasing. A braking force control device comprising: