JP2002255018A - Brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent operational feeling in regenerative and cooperative braking so that an operating stroke is equal to the operating stroke of a conventional independent frictional brake system without giving a plate pressing feeling to a driver. SOLUTION: When wheel cylinder pressures of wheel cylinders 7, 8, 9, and 10 are lowered in the regenerative and cooperative braking, electromagnetic opening/closing valves 34 and 53 are opened to lead a brake fluid in a master cylinder 4 into absorbing means 32 and 51. Thereby, a pedal stroke is allowed to be equal to a pedal stroke obtained when only a friction brake system is provided, and an excellent pedal operating feeling can be held in the regenerative and cooperative braking. In particular, when a brake pedal 2 is depressed (namely, a pedal pressing force is increased), a master cylinder pressure is limited by the decompression of the wheel cylinder pressure when the regenerative and cooperated brake is operated and, when the pressure is supplied to the wheel cylinder, the plate pressing feeling having hitherto been produced can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a brake system that operates a normal brake in cooperation with a regenerative braking force and a friction braking force, and in particular, controls a friction braking force according to the regenerative braking force. It belongs to the technical field of the brake system.

[0002]

2. Description of the Related Art In recent years, in a vehicle braking system, a regenerative braking system that performs braking with a regenerative braking force when converting the kinetic energy of the vehicle into electric energy during braking and a friction that performs braking with a friction braking force. A regenerative cooperative braking system that cooperates with a brake system has been proposed.

[0003] As one conventional example of the regenerative cooperative braking system, there is, for example, a brake system disclosed in Japanese Patent Application Laid-Open No. 7-336805. The brake system disclosed in this publication can control the hydraulic pressure of a wheel cylinder by a pressure increasing valve and a pressure reducing valve of an antilock brake mechanism, and can generate a friction braking torque with a braking torque requested by a driver. The control is performed such that the difference between the maximum values of the regenerative braking torques is obtained.

[0004]

By the way, in the regenerative cooperative braking system, including the brake system disclosed in this publication, the friction braking force is required by the driver by the amount of the generated regenerative braking force. Blaze
Key force (determined by the pedaling force when the brake pedal is depressed), that is, the braking force is limited to less than the friction braking force of a braking system using only the friction brake (hereinafter referred to as a single friction braking system). I have.

More specifically, in the case of a conventional single friction brake system, first, in order for the driver to operate the normal brake with the required braking force, a pedal corresponding to the required braking force is applied. When the brake pedal is depressed with the depressing force, the braking force increases along the line a as shown in FIG.
Become required braking force Ft ₀ along the normal braking by only the friction brake in the required braking force Ft ₀ is to operate.

At this time, the pedal stroke L in the normal brake operation using only the friction brake is shown in FIG.
To increase along the line indicated by a chain line alpha, when the brake force becomes required braking force Ft _0, setting the pedal stroke L ₀ along the certain line β which is set in correspondence with the required braking force Ft ₀ become.

On the other hand, in the case of the regenerative braking system, when the driver similarly depresses the brake pedal, as shown in FIG.
, The friction braking force Ff is the sum of the regenerative braking force Fr and the total braking force Ft.
Rises along a line d (below the line a, that is, a line with a small braking force) so as to be the same as the braking force along the line a, that is, the braking force in the case of normal braking in the single friction braking system. When the total braking force Ft has reached the required braking force Ft ₀ (at this time, the friction since brake force Ff is restricted smaller,
Frictional braking force Ff <required braking force Ft ₀ ), and regenerative braking force Fr still rises along line c, so that total braking force Ft is equal to braking force along line a. Along the line e. The friction braking force Ff at this time
This is achieved by discharging brake fluid from a wheel cylinder (hereinafter also referred to as W / C), which is a brake cylinder, to reduce the W / C hydraulic pressure (hereinafter also referred to as W / C pressure). However, the discharged brake fluid is returned to the master cylinder (hereinafter also referred to as M / C) side by the pump for increasing the W / C pressure thereafter.

Further, when the vehicle speed is reduced by the normal braking operation of the regenerative cooperation and the regenerative braking force Fr becomes constant along the line f as shown in FIG. 12, the friction braking force Ff and the total braking force Ft are reduced It becomes constant along the line g so that the required braking force Ft ₀ along the line b is obtained. The vehicle speed further decreases and the regenerative braking force Fr
There Decreasing along line h, the friction brake force Ff is increased along the line i so that the total braking force Ft becomes the required braking force Ft _0. At this time, the increase in the friction braking force Ff is caused by the fact that the brake fluid discharged from the W / C is returned to the M / C side by the pump, and
This is performed by supplying the brake fluid from C to the W / C. When the regenerative braking force Fr is eliminated, the friction brake force Ff is a constant demand braking force Ft ₀ along the line b. In this way, the normal brake by the regenerative cooperative brake is operated with the required brake force Ft ₀ requested by the driver corresponding to the pedal depression force.

At this time, the pedal stroke Lr in the normal brake operation by the regenerative cooperative brake is as shown in FIG.
When the total braking force Ft reaches the required braking force Ft0 when the _value increases along a line γ (a line below the line α, that is, a line with a small pedal stroke) indicated by a dotted line in FIG. Pedal stroke Lr ₁ (Lr ₁ <Lr ₀ ). Further, when the friction braking force Ff decreases along the line e, W / C
Since the brake fluid discharged from the pump is returned to the M / C side by the pump, the brake pedal is pushed back, so that the pedal stroke also decreases along the line δ. When the friction braking force Ff becomes constant along the line g, the pedal stroke becomes a constant Lr ₂ (Lr ₂ <Lr ₁ ) along the line ε. Further, when the friction braking force Ff increases along the line i, the brake fluid discharged from the W / C is returned to the M / C side by the pump, and the brake fluid is supplied from the M / C to the W / C. Therefore, the pedal stroke also increases along the line ζ. Then, the regenerative braking force disappears, when it only by the friction brake force to the required braking force Ft _0, the pedal stroke will set the pedal stroke L _0.

Therefore, in the regenerative braking system, when the W / C pressure is limited to a small value because the friction braking force Ff is limited to a small value, the amount of W / C consumed is smaller than in the case of the single friction brake system. As a result, the pedal stroke with respect to the driver's pedaling force is not only shorter than in the case of the single friction brake system, but also the pedal stroke is changed due to a change in the W / C pressure limit during the brake operation by the pedal depression. Will fluctuate.

As described above, in the regenerative braking system, the pedal stroke varies in a single normal braking operation, causing the driver to feel uncomfortable, resulting in poor pedal feeling. In particular, when the pedal is depressed (when the pedaling force is increased), the pedal stroke does not increase more than the pedal stroke in the single friction brake system (the brake pedal does not advance more than in the case of the single friction brake system), so that the driver feels a step on the board. And
There is a further problem that the pedal feeling is further deteriorated.

When the regenerative braking force decreases due to a decrease in vehicle speed, the demand for friction braking force increases,
Since the limitation on the W / C pressure is eliminated, the pedal stroke enters and the driver feels uncomfortable. Alternatively, if the driver tries to keep the pedal stroke constant at this time, the recovery of the W / C pressure becomes insufficient, so that the deceleration of the vehicle may be small and the stopping distance may be long.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a regenerative cooperative brake that does not cause the driver to feel a stepping on the board and that the operating stroke is the same as that of the conventional single-stroke operation. An object of the present invention is to provide a brake system capable of obtaining a good operation feeling in the same manner as the operation stroke of the friction brake system.

[0014]

In order to solve the above-mentioned problems, a brake system according to the present invention comprises a regenerative brake system and a friction brake system. A member, a master cylinder that generates a master cylinder pressure by a brake operation of the brake operation member, a brake cylinder that generates a friction braking force, and a brake fluid pressure control device that controls a brake fluid pressure of the brake cylinder, The brake fluid pressure control device restricts supply of fluid from the master cylinder to the brake cylinder,
Alternatively, there is provided brake fluid pressure limiting means for limiting the brake fluid pressure of the brake cylinder by discharging the fluid of the brake cylinder, and the brake fluid pressure is reduced by the brake fluid pressure limiting means. A hydraulic circuit between the master cylinder and the brake cylinder in a brake system that performs a regenerative cooperative brake operation by being controlled to be smaller than a brake hydraulic pressure when a regenerative brake is not operating in accordance with a force Is connected to an absorbing means for introducing and storing the brake fluid of the hydraulic circuit,
A liquid introducing means for controlling the introduction of the brake fluid to the absorbing means, and a fluid returning means for returning the brake fluid of the absorbing means to the hydraulic circuit are provided independently of the brake fluid pressure limiting means. Features.

[0015]

In the brake system of the present invention having such a configuration, when the brake fluid pressure of the brake cylinder is reduced during the regenerative cooperative braking, the brake fluid of the master cylinder is introduced into the fluid introducing means, so that the brake fluid is introduced. The operation stroke of the operation member does not fluctuate during the operation stroke of the brake operation member, and can be the same as the operation stroke of only the friction brake system. Thereby, the operation feeling of the operation member is favorably maintained during the regenerative cooperative braking. In particular, when the operation member is operated (that is, when the operation amount is increased), when the master cylinder pressure is limited and supplied to the brake cylinder due to the decrease in the brake fluid pressure of the brake cylinder in the regenerative cooperative braking operation, a plate that has conventionally occurred Since the feeling of stepping is eliminated, the operation feeling is further improved.

Further, the absorbing means, the liquid introducing means, and the liquid returning means can be provided independently of the brake hydraulic pressure control device. The operation stroke of the operation member can be controlled without affecting the control of the brake fluid pressure of the brake cylinder during regenerative cooperative braking. Therefore, the operation stroke can be controlled more accurately and more easily according to the required braking force at the time of the regenerative cooperative braking.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram schematically showing a first example of an embodiment of a brake system according to the present invention.

The brake system 1 of the first example is provided with a regenerative brake system (not shown) as required when a brake such as a normal brake is operated by depressing a brake pedal.
Is a regenerative braking system that obtains a necessary braking force from the regenerative braking force and the friction braking force by operating in cooperation with the friction braking system. As shown in FIG. 1, the friction brake system in the brake system 1 of the first example is a negative pressure booster 3 that boosts the pedaling force of a brake pedal (corresponding to a brake operating member of the present invention) 2 by negative pressure and outputs the boosted force. And a tandem type M / C 4 operated by the output of the negative pressure booster 3 to generate an M / C pressure.
And W / Cs 7, 8, 9, 10 (which generate a braking force by supplying the M / C pressures of the respective liquid chambers of the M / C 4 through two passages 5, 6). In the example, W
/ C7,8 are provided for the left and right front wheels, and W / C
9 and 10 are provided for the left and right rear wheels, but the present invention is not limited to this). In addition to performing antilock brake control (hereinafter also referred to as ABS control) for adjusting W / C pressures of W / Cs 7, 8, 9, and 10, drive wheels (for example, left and right front wheels; hereinafter, left and right front wheels serve as drive wheels) However, the present invention is not limited to this. Needless to say, appropriate wheels such as right and left rear wheels or all wheels can be used as drive wheels. A traction control (hereinafter, also referred to as TRC control) for automatically applying pressure fluid to at least the W / Cs 7 and 8 of the idling drive wheels so as to cancel the drive wheels so as to solve the problem, and further, a turning angle of the vehicle However, when the angle does not match the angle corresponding to the driver's steering wheel operation amount, the brake is automatically sent by sending pressure fluid to the appropriate W / C 7, 8, 9, 10 of the front, rear, left and right wheels. The vehicle stability control for stabilizing the turning angle of the vehicle by applying the braking force to the vehicle. Brake assist control (hereinafter also referred to as BA control) for automatically assisting the braking force by sending pressure fluid to the W / Cs 7, 8, 9, and 10, and further, automatically activates the brake in auto cruise and the like. A two-system brake fluid pressure control device 11 for performing automatic brake control,
And a reservoir 12 for storing brake fluid.

In this case, when the brake pedal 2 is depressed, the negative pressure booster 3 outputs and the friction brake operates, and the depression of the brake pedal 2 is detected by a pedal depression detection sensor (not shown) and is input to a controller (not shown). The regenerative brake is operated by the controller based on the pedal depression detection information.

When the brake pedal 2 is depressed,
A M / C pressure generated by the M / C 4 is measured by a pressure sensor 56 described later.
By inputting the information of the M / C pressure to the controller, the controller can operate the regenerative brake based on the information of the M / C pressure.

Further, the controller may be provided with a controller for the brake fluid pressure control device 11 of the friction brake system and a controller for the regenerative brake system in common, or may be provided separately for the friction brake system and the regenerative brake system, respectively. Further, they can be provided so as to be connected to each other. Furthermore, this brake system 1
Can operate the brake only by the friction braking force as in the case of the conventional single friction brake system without operating the regenerative brake.

The negative pressure booster 3 is a conventional well-known general one. Therefore, detailed description thereof will be omitted.
A control valve (not shown) is switched to supply the atmosphere to a variable pressure chamber partitioned by a diaphragm piston (not shown). A power piston is actuated, and a pedal depression force (corresponding to a brake operation force of the present invention) is boosted by the power piston and output from an output shaft (not shown). Is activated.

The M / C 4 is a conventional well-known general tandem type M / C having a primary piston and a secondary piston (not shown). The primary piston is operated by the output of the device 3 to generate an M / C pressure in a first hydraulic chamber (not shown), and the secondary piston is operated by this M / C pressure to produce a second hydraulic chamber (not shown). ) Generates M / C pressure,
The M / C pressures of the first and second hydraulic chambers are sent out to corresponding W / Cs 7, 8, 9, and 10 via passages 5 and 6, respectively.

The passage 5 of one system is branched into first and second branch passages 5a and 5b. The first branch passage 5a is connected to one W / C 7 of the system, and the second branch passage 5b is connected to one of the W / Cs. Each is connected to the other W / C 8 of the system. Also,
Similarly, the third and fourth branch passages 6a,
The third branch passage 6a is connected to one W / C 9 of another system, and the fourth branch passage 6b is connected to the other W / C 10 of another system.

The M / C 4 and the first and second branch passages 5a,
In the passage 5 between the branch point A of FIG.
Is provided in parallel with the on-off valve 14 with a relief valve. The on-off valve 14 with a relief valve is an electromagnetic valve, and is set to the left communication position when not in operation and to the right relief valve position when in operation. In this case, the relief valve opens when the hydraulic pressure on the W / C7, 8 side of the on-off valve 14 with a relief valve becomes higher than the hydraulic pressure on the M / C4 side by a predetermined pressure or more. The hydraulic pressure on the W / C 7, 8 side is released to the M / C 4 side. The relief pressure of the relief valve is variable. Also,
Check valve 15 is M / C of on-off valve 14 with relief valve.
Only the flow of the brake fluid from the 4 side to the W / C 7, 8 side is allowed.

Similarly, in the passage 6 between the M / C 4 and the branch point B of the third and fourth branch passages 6a and 6b, the on-off valve 14 with a relief valve and the check valve 15 of the passage 5 are also provided.
An on-off valve 16 with a relief valve and a check valve 17 are provided. The on-off valve 16 with a relief valve is an electromagnetic valve, and is set to the left communication position when not in operation and to the right relief valve position when in operation. In this case, the relief valve has a hydraulic pressure of M / C4
When the pressure becomes higher than a predetermined pressure (relief pressure) from the hydraulic pressure of the relief valve, the hydraulic pressure on the W / C 9, 10 side of the on-off valve 16 with a relief valve is released to the M / C 4 side. The relief pressure of the relief valve is variable. Also,
Check valve 17 is M / C of on-off valve 16 with relief valve.
Only the flow of the brake fluid from the 4 side to the W / Cs 9 and 10 is allowed.

In the first and second branch passages 5a and 5b,
Intensifier valves 18, each of which is a normally open solenoid on-off valve,
19, and these pressure-intensifying valves 1
Check valves 20, 21 that allow only the flow of the brake fluid from the W / C 7, 8 side to the M / C 4 side of the 8, 19 are provided in parallel with the corresponding pressure increasing valves 18, 19, respectively. Further, a discharge passage 22 is branched from a first branch passage 5a on the W / C 7 side from the pressure increasing valve 18, and the discharge passage 22 is connected to an AB on one system side of the brake fluid pressure control device 11.
It is connected to an ABS reservoir (corresponding to a brake fluid pressure control reservoir of the present invention) 23 from which brake pressure is discharged from at least one of the W / Cs 7 and 8 when the brake pressure is reduced in S control. The discharge passage 22 is provided with a pressure reducing valve 24 composed of a normally closed electromagnetic open / close valve. Similarly, a discharge passage 25 is branched from the first branch passage 5b on the W / C 8 side from the pressure increasing valve 19, and the discharge passage 25 communicates with the ABS reservoir 23. The discharge passage 25 is also provided with a pressure-reducing valve 26, which is also a normally closed electromagnetic on-off valve.

Each of the pressure-increasing valves 18 and 19 and the pressure-reducing valves 24 and 26 provides a friction braking force Ff by the regenerative braking force Fr during the regenerative braking operation.
The brake fluid pressure limiting means for limiting the W / C pressures of the W / Cs 7 and 8 to a small value in order to reduce the W / C.

Further, the circulation passage 27 connecting the ABS reservoir 23 and the branch point A of the first and second branch passages 5a and 5b allows only the flow of the brake fluid from the ABS reservoir 23 to the branch point A. Three check valves 28,
29 and 30 are provided respectively, and a pump 3 is provided between the two check valves 28 and 29 on the branch point A side.
1 is provided.

Further, the stroke of each piston of M / C4
(Hereinafter referred to as M / C piston stroke; pedal stroke
From the M / C4 to adjust the
Absorption means 3 consisting of an accumulator into which the storage liquid is introduced
2 are provided. This absorbing means 32 is provided with a brake fluid.
Chamber 32a into which is introduced, and this absorption chamber 32a is partitioned.
Absorbing piston 32b, and the absorbing piston 32b
Is constantly biased in a direction to narrow the absorption chamber 32a.
Ring 32c.

The absorption chamber 32a is connected to a passage 5 on the M / C 4 side of the on-off valve 14 with a relief valve via a passage 33. The passage 33 is provided with a liquid introduction unit for introducing the brake fluid from the M / C 4.
This liquid introducing means includes a normally closed electromagnetic on-off valve 34.
Also, the passage 33 between the electromagnetic on-off valve 34 and the absorption chamber 32a and the recirculation passage 2 between the two check valves 29, 30
7 is provided. Pump 31
Is a liquid return means for returning the brake fluid in the absorption chamber 32a to the branch point A. In this case, both the liquid introduction means and the liquid return means are provided independently of the above-described brake fluid pressure restriction means of the brake system.

On the other hand, in other brake systems, the second
And the third branch passages 6a, 6b are provided with pressure-intensifying valves 37, 38, each of which is a normally-open electromagnetic on-off valve.
Check valves 39 and 40 that allow only the flow of the brake fluid from the 9 and 10 sides to the M / C 4 side are provided in parallel with the corresponding pressure increasing valves 37 and 38, respectively. Also,
A discharge passage 41 is branched from the third branch passage 6a on the W / C 9 side from the pressure increasing valve 37, and the discharge passage 41 is connected to the brake fluid pressure control device 11 when the brake pressure is reduced by the ABS control on the other system side. It communicates with an ABS reservoir 42 from which brake pressure is discharged from at least one of C9 and C9. The discharge passage 41 is provided with a pressure reducing valve 43 composed of a normally closed electromagnetic on-off valve. Similarly, a discharge passage 44 is branched from the fourth branch passage 6b on the W / C 10 side from the pressure increasing valve 38, and the discharge passage 44 communicates with the ABS reservoir 42. The discharge passage 44 is also provided with a pressure-reducing valve 45, which is also a normally-closed electromagnetic on-off valve.

The pressure-increasing valves 37 and 38 and the pressure-reducing valves 43 and 45 respectively provide the friction braking force Ff by the regenerative braking force Fr during the regenerative braking operation.
The brake fluid pressure limiting means for limiting each W / C pressure of each of the W / Cs 9 and 10 to a small value in order to reduce the pressure.

The recirculation passage 46 connecting the ABS reservoir 42 and the branch point B of the third and fourth branch passages 6a and 6b allows only the flow of the brake fluid from the ABS reservoir 42 to the branch point B. Three check valves 47,
48 and 49, respectively, and a pump 5 is provided between the two check valves 47 and 48 on the branch point B side.
0 is provided.

Further, an absorbing means 51 comprising an accumulator into which brake fluid is introduced for adjusting the M / C piston stroke is provided. This absorbing means 51
Includes an absorption chamber 51a into which the brake fluid is introduced, an absorption piston 51b that partitions the absorption chamber 51a, and a spring 51c that constantly urges the absorption piston 51b in a direction to narrow the absorption chamber 51a. .

The absorption chamber 51a is connected to a passage 6 on the M / C 4 side of the on-off valve 16 with a relief valve via a passage 52. The passage 52 is provided with a liquid introduction unit for introducing the brake fluid from the M / C 4.
This liquid introduction means includes a normally closed electromagnetic on-off valve 53.
Further, a passage 52 between the electromagnetic on-off valve 53 and the absorption chamber 51a and a recirculation passage 4 between the two check valves 48 and 49 are provided.
6 is provided. Pump 50
Is a liquid return means for returning the brake fluid in the absorption chamber 51a to the branch point B. In this case, both the liquid introduction means and the liquid return means are provided independently of the above-described brake fluid pressure restriction means of the brake system.

Further, the M / C 4 and the on-off valve with relief valve 14
A pressure sensor 5 for detecting the M / C pressure
6 are provided. By this pressure sensor 56, M /
By detecting the C pressure, the driver's pedal depression force in the brake operation at that time is detected.

Each W / W of each branch passage 5a, 5b, 6a, 6b
At least one of the W / C pressure sensors 82, 83, 84, 85 is provided between C7, 8, 9, 10 and each of the pressure-intensifying valves 18, 19, 37, 38, and controls the W / C pressure. Is to be detected. And each solenoid valve (14, 16, 18, 19, 2
4, 26, 34, 37, 38, 43, 45, 53), pump driving means such as a motor for driving each of the pumps 31, 50 (not shown: may be provided in common or may be provided separately) , And the pressure sensor 56 and the W / C pressure sensors 82, 83, 84, 85 are respectively connected to the above-described controller.

In the brake system 1 of the first example, in order to control the amount of liquid in each of the absorption chambers 32a and 51a, each of the electromagnetic on-off valves 34 and 53 and the pumps 31 and 50 are provided with an M / C.
The control is performed in accordance with the pressure and each W / C pressure.

In the thus configured brake system 1 of the first example, when the brake pedal 2 is not depressed and the normal brake is not operated, all the components are at the non-operating positions shown in the drawing. In the normal brake non-operation state, the negative pressure booster 3 does not operate, the M / C 4 does not generate the M / C pressure, and the W / Cs 7, 8, 9, 1, 1
0 communicates with the reservoir 12 through the corresponding passages 5 and 6 and the respective hydraulic pressure chambers of the solenoid valves 18, 19, 37, 38, 14, 16 and the M / C 4 to reach the atmospheric pressure. Therefore, no W / C pressure (brake pressure) is generated in each of the W / Cs 7, 8, 9, and 10. Further, the pumps 31 and 50 do not operate. Further, a regenerative brake (not shown) does not operate.

When the driver performs a normal brake operation with the brake pedal 2 normally depressed from the brake non-operation state, both the regenerative brake and the friction brake operate. That is, the controller operates the regenerative brake based on the pedal depression detection information described above. On the other hand, when the brake pedal 2 is depressed, the negative pressure booster 3 is actuated to boost and output the pedal depression force, and the M / C 4 generates an M / C pressure based on the pedal depression force. These M / C pressures correspond to the corresponding passages 5, 6 and the respective solenoid valves 14, 1 respectively.
Each W / C 7, 8, 9, 1 via 6, 18, 19, 37, 38
0 is supplied.

At this time, the regenerative braking force by the regenerative brake is input to the controller, and the M / C based on the pedal depression force detected by the pressure sensor 56 is used.
Pressure is input to the controller. The controller uses this M
/ C pressure is calculated based on the pedal depression force, and the required braking force Ft requested by the driver by the calculated pedal depression force
Calculate ₀ . Then, as shown in FIG. 12, since the total braking force Ft in the normal braking rises along the line a, the difference between the total braking force Ft and the regenerative braking force Fr rising along the line c causes the line d to increase. Required friction braking force (that is, each W /
Required braking force generated by C7, 8, 9, and 10;
f) and the required W / C pressure corresponding to the required friction braking force Ff.

Then, the controller controls each of the pressure increasing valves 1
8, 19, 37 and 38 are respectively controlled to open and close by, for example, PWM control (duty control). Then, M / C4
The brake fluid from the W / C7,8,
The W / Cs 7, 8, 9, and 10 are controlled to increase the pressure so that the required W / C pressure is obtained. Thereby, the required friction braking force Ff increases along the line d. Therefore, during the normal braking operation, the regenerative braking force Fr and the required friction braking force Ff are coordinated to obtain a total braking force Ft along the line a.

At this time, in the brake system 1 of the first example, the brake from the M / C 4 to the respective W / Cs 7, 8, 9, 10 by the opening / closing control of the pressure boosting valves 18, 19, 37, 38 described above. Along with the liquid supply, the controller controls the opening and closing of each of the electromagnetic on-off valves 34 and 53 by, for example, PWM control.

In this case, the controller operates the pressure sensor 5
6, the M / C piston stroke in the single friction brake system for generating the M / C pressure is calculated, and the W / C pressure and the M / C pressure are used to calculate each W / C7. , 8, 9, and 10, the brake from the M / C 4 to each of the absorption chambers 32a and 51a so that the M / C piston stroke becomes the M / C piston stroke in the single friction brake system. Calculate the amount of liquid introduced. Then, the controller controls each of the electromagnetic on-off valves 34 and 53 so that the amount of the brake fluid introduced into each of the absorption chambers 32a and 51a becomes the calculated introduction amount.
At this time, the amount of the brake fluid introduced into each of the absorption chambers 32a and 51a is estimated based on the opening control time of each of the electromagnetic on-off valves 34 and 53.

In this manner, by controlling the opening and closing of each of the electromagnetic switching valves 34 and 53, the calculated amount of the brake fluid from the M / C 4 is introduced into each of the absorption chambers 32a and 51a. Therefore, the pedal stroke is the required pedal stroke along the line α (corresponding to the pedal stroke L at the time of the brake operation in the aforementioned single friction brake system,
Thereafter, the stroke of each piston of the M / C 4 is controlled so as to be L). As a result, the way of increasing the pedal stroke L is not shortened like the change along the line γ, so that the driver does not feel the feeling of stepping on the pedal when depressing the pedal, and the pedal feeling is improved.

[0047] When the total braking force Ft reaches a required braking force Ft _0, the pedal stroke Lr becomes alone friction set in the brake system pedal stroke L ₀ and the same setting the pedal stroke L _0. M / C at this time
Since the pressure is detected by the pressure sensor 56 and input to the controller, and the regenerative braking force Fr that still rises along the line c is input to the controller, the controller increases the pressure of each of the pressure-intensifying valves 18, 19, 37, and 38. Is closed, and the pressure reducing valves 24, 26, 43, 45 are respectively opened and closed by, for example, PWM control. Then, the brake fluid of each W / C 7, 8, 9, 10 is discharged to each ABS reservoir 23, 42, and the W / C pressure of each W / C 7, 8, 9, 10 is reduced to the required W / C pressure described above. The decompression control is performed as follows. As a result, the required friction braking force Ff is reduced to the line e.
Decrease along.

Therefore, when the regenerative cooperative brake is operated,
Even if the regenerative braking force Fr increases along the line c, the required braking force Ft ₀ requested by the driver is maintained. Thus, normal braking by the regenerative cooperative brake this required braking force Ft ₀ is activated.

At the same time, the controller controls the opening and closing of each of the electromagnetic on-off valves 34 and 53 by the PWM control or the like in which the control ratio (duty ratio) such as the above-mentioned PWM control is changed. Thereby, the brake fluid from the M / C 4 is introduced into each of the absorption chambers 32a and 51a. At this time, the introduction amount of the brake fluid introduced into each of the absorption chambers 32a and 51a is estimated based on the opening control time of each of the electromagnetic on-off valves 34 and 53, as described above.

In that case, the controller also controls the M / C
The M / C piston stroke in the single friction brake system is calculated based on the pressure, and the W / C pressure, the M / C pressure, and the driving time of each pump 31, 50 are used to calculate each W / C 7, 8,
Estimating the amount of fluid consumed at 9, 10 and the amount of fluid discharged to the ABS reservoirs 23, 42, the M / C piston stroke is set to M / C in the single friction brake system based on the estimated fluid amount.
Each of the absorption chambers 32a,
The amount of each brake fluid introduced from M / C4 into 51a is calculated. Then, the controller controls each of the absorption chambers 32a, 51
The electromagnetic on-off valves 34 and 53 are controlled to open and close in the same manner as described above so that the amount of brake fluid introduced into a becomes the calculated amount. Thereby, each brake fluid from the M / C 4 and each pump 31, 50 is introduced into each absorption chamber 32a, 51a. At this time, the absorption chambers 32a, 51
The amount of the brake fluid introduced into the solenoid valve 3
Estimated based on 4,53 open control times.

By controlling the opening and closing of each of the electromagnetic on-off valves 34 and 53, the brake fluid from the M / C 4 is introduced into each of the absorption chambers 32a and 51a by the calculated introduction amount. It is held at the pedal stroke L ₀ and does not change so as to decrease along the aforementioned line δ.

As shown in FIG. 12, when the regenerative braking force Fr reaches the maximum regenerative braking force and becomes constant along the line f, constant information on the regenerative braking force Fr is input to the controller. Booster valve 1
8, 19, 37, 38 are kept closed, and the pressure reducing valves 24, 26, 43, 45 and the electromagnetic on-off valves 34, 53
Also close each. Then, each W / C 7, 8, 9, 10
Are M / C4 and each pressure reducing valve 24, 26, 43, 4
5, the W / C pressure is kept constant. Therefore, the required friction braking force Ff also becomes constant along the line g, and the normal braking operation by the regenerative cooperative brake continues while the required braking force Ft ₀ is maintained.

At this time, the controller
8, 19, 37, 38, each pressure reducing valve 24, 26, 43, 4
5 and each of the electromagnetic on-off valves 34 and 53 are closed, so that the brake fluid consumption on the M / C4 side does not change from each of the pressure increasing valves 18, 19, 37 and 38. That is, the pedal stroke Lr is held at the set pedal stroke L ₀ ,
There is no constant stroke Lr ₂ along the line ε described above.

Normally, the vehicle speed is reduced by the operation of the brake,
As shown in FIG. 12, when the regenerative braking force Fr decreases along the line h, information on the decrease in the regenerative braking force Fr is input to the controller. In addition to the control, the pressure-intensifying valves 18, 19, 37, and 38 are again controlled to open and close by, for example, PWM control. Then, the brake fluid discharged to the ABS reservoirs 23 and 42 and the brake fluid introduced to the absorption chambers 32a and 51a are discharged by the pumps 31 and 50 to the branch points A and B, respectively. The brake fluid supplied from the M / C 4 supplied through the opening / closing valves 14 and 16 with the relief valve for operation is controlled by the opening / closing control of the pressure-intensifying valves 18, 19, 37 and 38 while controlling the flow rate of each of the W / Cs 7 and 8. , 9,
10 is supplied. Each of the pumps 31 and 50 constitutes a return pump of the present invention.

As a result, the W / C 7, 8, 9, 10 W
The pressure increase control is again performed so that the / C pressure becomes the required W / C pressure,
The required friction braking force Ff increases along the line i.
Thus, the required braking force Ft ₀ corresponding to the pedaling force
Is maintained, and the normal brake operation by the regenerative cooperative brake continues at the required braking force Ft ₀ .

At this time, the discharge flow rate of each of the pumps 31 and 50 is controlled by, for example, PWM control.
The fluid is discharged to each of the branch points A and B while being controlled to be equal to the flow rate of the fluid flowing at 7, 38. Thus, the M / C piston stroke, i.e. the pedal stroke to be increased suppression, the pedal stroke by the stroke control is held at the required maximum pedal stroke L _0, no change is to increase along the line i of the above .

When the regenerative braking force Fr is extinguished, information on the disappearance of the regenerative braking force Fr is input to the controller. Then, the pumps 31 and 50 are stopped. Then, only the brake fluid from the M / C 4 controls the flow rate of each W / C 7,
8, 9, and 10. As a result, the M / C pressure generated by the output of the negative pressure booster 3 which boosts the pedal depression force is supplied to each of the W / Cs 7, 8, 9, and 10 without being restricted, and is required only by the friction braking force. held braking force Ft ₀ is the normal braking actuated. At this time, M / C
Since the required brake force Ft ₀ is generated only by the pressure, the required pedal stroke L is kept at the set pedal stroke L ₀ when only the friction brake is used.

[0058] In this way, after the total braking force Ft is increased along the line a by a conventional regenerative cooperative brake during braking operation, with the normal braking to operate at the required braking force Ft _0, required pedal stroke Lr
Rises along the line α, and becomes the set pedal stroke L ₀ corresponding to the pedal depression force at that time.

When the normal brake operation is released by releasing the brake pedal 2, the negative pressure booster 3 is deactivated as in the case of the conventional negative pressure booster, and M
/ C4 is deactivated, and the M / C pressure disappears. Based on the disappearance information of the M / C pressure from the pressure sensor 56, the controller determines whether each of the pressure increasing valves 18, 19, 37, 38 and each pressure reducing valve 2
4, 26, 43, 45 and the respective solenoid on-off valves 34, 53 are set to the inactive state shown in FIG.
Stop 1,50. Thereby, each W / C 7, 8, 9, 1
The brake fluid of 0 is discharged to the reservoir 12 of M / C4,
Since each W / C pressure disappears and the friction brake is released, and the regenerative brake is released, the normal brake is released. When the brake pedal 2 is released while the regenerative braking is occurring, the controller releases the regenerative braking operation based on the information about the pedal release from the pedal depression detection sensor, and as described above. When the friction brake operation is released, the normal brake by the regenerative cooperation is released.

In the brake system 1 of the first example, ABS control, TRC control, vehicle stability control, BA control, and automatic brake control are also performed. Since these controls are performed in the same manner as in the related art, a detailed description thereof will be omitted. First, a brief explanation.

First, in the ABS control, when a tendency to lock a wheel is detected during normal brake operation based on each wheel speed information from each wheel speed sensor, at least the W / C of the wheel having a tendency to lock is determined by the controller. The opening / closing of the pressure-increasing valves 18, 19, 37, 38 and the pressure-reducing valves 24, 26, 43, 45, respectively, is controlled, and the pumps 31, 50 are drive-controlled to adjust the W / C pressure according to the locking tendency. By performing pressure reduction control, pressure increase control, and holding control (holding control may be omitted in some cases), ABS control is performed so that the locking tendency is eliminated.

In the TRC control, when the idling tendency of the driving wheel is detected at the time of starting or sudden acceleration based on the wheel speed information from the wheel speed sensor of the driving wheel, the controller determines at least the driving tendency of the driving wheel which is idling. W / C 7,8,
The on-off valves 14 and 16 with relief valves corresponding to 9 and 10 are set to the relief valve position, and the W / Cs 7, 8 and
9, 10 and W / C 7, 8, 9,
Intensifier valves 18, 19, 37, 3 respectively corresponding to 10
8, the solenoid valves 34, 36, 53, and 55 of the brake system corresponding to the drive wheels that tend to run idle are opened, and the pumps 31 and 50 of the brake system corresponding to the drive wheels that tend to run idle are further driven. Then, the brake fluid of the reservoir 12 is supplied to the W / Cs 7, 8, 9, and 10 of the drive wheels that have a tendency to idle, and the brake is applied to the drive wheels that have a tendency to idle according to the magnitude of the idle tendency. TRC control is performed so that the idling tendency is eliminated.

In the vehicle stability control, the turning of the vehicle in response to the driver's steering request is performed on the basis of the driver's steering amount information from the steering wheel angle sensor and the vehicle lateral rotation angular velocity information from the yaw rate sensor. When it is detected that the angle is insufficient, the controller sets at least the on-off valve with relief valve 16 corresponding to each of the W / Cs 9 and 10 of the rear wheels to the relief valve position, and sets the electromagnetic on-off valve 5
3 is opened, the pressure-intensifying valves 18 and 19 corresponding to the W / Cs 7 and 8 of the front wheels are closed, and the W / Cs 9 and 10 of the rear wheels are closed.
Is controlled by PWM control or the like, and the pumps 31 and 50 are drive-controlled by PWM control or the like to supply the brake fluid of the reservoir 12 to each W / W of the rear wheels.
The vehicle is supplied to C9 and C10, and by applying a brake to the rear wheels in accordance with the magnitude of the tendency of insufficient turning angle, vehicle stability control is performed so as to increase the amount of side slip of the rear wheels and eliminate the insufficient turning angle. . On the other hand, when it is detected that the turning angle of the vehicle is excessive and there is a possibility of causing a spin, the controller sets at least the on-off valve 14 with a relief valve corresponding to the W / C 7, 8 of the turning outer front wheel to the relief valve position. And
Open the solenoid on-off valve 34 and open the W / C
7, 8, 9, and 10 corresponding to the pressure intensifier valves 18, 19, 37,
38, the pressure-intensifying valves 18 and 19 corresponding to the W / Cs 7 and 8 of the turning outer front wheels are controlled to open and close by PWM control and the like, and the pumps 31 and 50 are drive-controlled by PWM control and the like to brake the reservoir 12. Swirling the liquid W of the outer front wheel
/ C7, 8 to apply a brake to the front wheel on the outside of the turn in accordance with the tendency of the turning angle to be excessive, whereby the vehicle stability control is performed so as to eliminate the excessive turning angle.

Further, in the BA control, when the driver depresses the brake pedal 2 to perform a brake operation,
The controller calculates the pedal depression speed based on the pedal depression detection information from the pedal depression detection sensor described above, and based on the pedal depression speed, the required braking force requested by the driver and the required M corresponding to the required braking force. / C pressure (that is, required W / C pressure) is calculated. Then, when the M / C pressure is smaller than the required M / C pressure calculated from the pressure sensor 56 and is insufficient,
The controller sets each of the on-off valves 14 and 16 with a relief valve to the relief valve position and sets each of the electromagnetic on-off valves 34 and 5.
3 and further drive the pumps 31 and 50 so that the M / C4
BA control that assists the braking force by supplying the brake fluid in each hydraulic chamber to each W / C 7, 8, 9, 10 and controlling each W / C pressure to the required W / C pressure Is performed.

Further, in the automatic brake control, when the controller determines that it is necessary to apply a brake to the own vehicle based on the inter-vehicle distance from the preceding vehicle, the vehicle speed, and the like, for example, at a constant speed, the controller determines whether it is necessary to apply the brake. The required braking force and the required W / C pressure are calculated. Further, the controller sets each of the on-off valves 14 and 16 with a relief valve to the relief valve position, opens each of the electromagnetic on-off valves 34 and 53, and further drives the pumps 31 and 50 to supply the brake fluid of the reservoir 12 to each W. / C7,8,9,10 to supply each W /
By controlling the C pressure to be the required W / C pressure,
Automatic brake control for automatically operating the brake is performed.

Note that these ABS control, TRC control,
In the vehicle stability control, the BA control, and the automatic brake control, when controlling each W / C pressure, when performing by regenerative cooperative braking, the total braking force is set to a desired braking force in each control. However, the friction braking force is controlled to be smaller by the regenerative braking force in the same manner as in the regenerative cooperative braking described above. Is controlled so as to attain the desired braking force.

As described above, according to the brake system 1 of the first example, the pedal stroke changes even when the normal braking operation is performed by reducing the friction braking force by the regenerative braking force by the regenerative cooperative braking. This is the same as the pedal stroke in the conventional single friction brake system, and the pedal feeling can be maintained well. In particular, when the pedal is depressed (that is, when the pedaling force is increased), the M / C pressure is limited by the regenerative cooperative brake, and the W / C7,
When supplied to 8, 9, and 10, the above-described feeling of stepping on the plate is eliminated, so that the pedal feeling can be further improved.

Further, since the liquid introducing means, the liquid returning means, and the absorbing means 32, 51 are provided independently of the brake fluid pressure limiting means, the control of each W / C pressure at the time of regenerative coordination is not affected. And the pedal stroke can be controlled. Therefore, it is possible to more accurately and easily control the pedal stroke in accordance with the total braking force Ft during regenerative cooperation.

Further, since the respective solenoid on-off valves 34 and 53 and the pumps 31 and 50 of the brake fluid pressure control device 11 such as an ABS control device, which are conventionally used, are also used for pedal stroke control, the structure is simplified. In addition to being able to achieve the structure, it can be constructed at a low cost.

FIG. 2 is a view showing a second example of the embodiment of the brake system according to the present invention. In the following description of each example of the embodiment, the same reference numerals are given to the same components as those of the example described before the example, and the detailed description thereof will be omitted.

In the above-described first example, the fluid discharged from each brake cylinder 7, 8, 9, 10 by opening control of each pressure reducing valve 24, 26, 43, 44 during the regenerative cooperative braking operation causes the ABS reservoir 23 , 42, when each pump is driven, the relatively high pressure of each absorption chamber 32a,
After the liquid of 51a is refluxed, each ABS at a relatively low pressure
Since the liquids in the reservoirs 23 and 42 are circulated, the liquid is normally stored in the ABS reservoir. Therefore, if the wheels tend to lock when the regenerative braking is activated, a sufficient amount of fluid cannot be discharged from the brake cylinder of the wheels having the lock tendency to the ABS reservoir, and the pressure reduction control in the ABS control may be hindered.

Therefore, the brake system 1 of the second example
Then, as shown in FIG. 2, each electromagnetic switching valve 3 for controlling connection / disconnection of each passage 35, 54 connecting each absorption chamber 32a, 51a to the suction side of each pump 31, 50 as liquid return means.
6,55 are provided. In the first example described above,
The W / C pressure is detected by at least one of the W / C pressure sensors 82, 83, 84, 85.
In the example brake system 1, as shown in FIG.
The C pressure sensor has been eliminated. Other configurations of the brake system 1 of the second example are the same as those of the first example.

In the brake system 1 of the second example configured as described above, the controller
The W / C pressure is estimated from the previously closed control states of 8, 19, 37, 38 and the previously opened control states of the pressure reducing valves 24, 26, 43, 44, and the M / C pressure detected by the pressure sensor 56. Then, using the estimated W / C pressure, the control of the above-described brake fluid pressure limiting means and the control of the fluid introduction means and the fluid return means are performed. Further, the controller determines the estimated W / C
The liquid amounts in the ABS reservoirs 23 and 42 are estimated from the pressure, the open control states of the pressure reducing valves 24, 26, 43 and 44, and the drive control states of the pumps 31 and 50 so far.

When the brake fluid is discharged to the ABS reservoirs 23 and 42 by the opening control of the pressure reducing valves 24, 26, 43 and 44, the pumps 31 and 50 are opened and closed by PWM control or the like. At this time, by closing the electromagnetic on / off valves 36 and 55, the pumps 31 and 50 discharge the brake fluid discharged to the ABS reservoirs 23 and 42 in the respective branch points A and B, that is, in the M / C4 direction. Along with
The pump discharge liquid is introduced into each of the absorption chambers 32a and 51a.
When it is determined that the brake fluid in the ABS reservoirs 23 and 42 has almost circulated by the above estimation, the pump 31,
The drive of 50 is stopped.

When the regenerative braking force is reduced and the brake fluid stored in each of the absorption chambers 32a, 51a is recirculated, when the pumps 31, 50 are started to be driven, both the electromagnetic on-off valves 36, 55 are turned off. When it is determined that the brake fluid in the ABS reservoirs 23 and 42 has substantially circulated by the above-described estimation, the electromagnetic valves 36 and 55 are opened, and the brake fluid introduced into the absorption chambers 32a and 51a is released. Circulate.

As described above, according to the brake system 1 of the second example, by estimating the W / C pressure, the W / C
Since the pressure sensor can be omitted, the space can be saved and the cost can be reduced.

Further, the ABS is provided from each W / C 7, 8, 9, 10
Since the brake fluid discharged to the reservoirs 23 and 42 is immediately supplied to the branch points A and B by the pumps 31 and 50, respectively, the brake fluid is regenerated to the ABS reservoirs 23 and 42 having a relatively small capacity. Even if the brake fluid is discharged by the cooperation, the brake fluid can always be maintained in a state where substantially no brake fluid is stored in the ABS reservoirs 23 and 42. Therefore, even if the wheels tend to lock during the braking operation by the regenerative cooperative brake, the pressure reduction control in the ABS control can be reliably performed on the wheels that tend to lock.

In particular, the brake fluid in each of the ABS reservoirs 23, 42 and each of the absorption chambers 32a, 51a is supplied to each of the pumps 31,5.
At the time of recirculation toward the branch points A and B at 0, the brake fluid in each of the ABS reservoirs 23 and 42 is first recirculated, and then the brake fluid in each of the absorption chambers 32a and 51a is recirculated. Therefore, it is possible to reliably cope with the pressure reduction control in the ABS control.

The liquid return means of the second example uses a drive control such as a PWM control for the pumps 31 and 50 as described above. By controlling the opening and closing of each of the electromagnetic on-off valves 36 and 55 by PWM control or the like, it is possible to use a liquid return unit. In this case, the liquid on / off valves 36, 5
5 and each of the absorption chambers 32a and 51a and each of the pumps 31 and 5 are provided.
Since the communication with the pump 0 can be cut off,
The rotation speed of 50 can be set to the rotation speed of the conventional brake control such as ABS regardless of the pedal stroke control. Thus, the cost of the pump driving device for driving the pump can be reduced.

FIG. 3 is a view showing a third example of the embodiment of the brake system according to the present invention. In the first and second examples described above, during the BA control, each of the electromagnetic on-off valves 34, 5
3 (36, 55 in the second example) is opened and M / C4
Brake fluid flows through each passage 35, 54 to each pump 3
The suction fluid is sucked by 1, 50 and discharged toward each branch point A, B. At this time, since the absorption chambers 32a, 51a are connected to the passages 35, 54, the brake fluid of the M / C 4 is discharged. It flows into each of the absorption chambers 32a and 51a, and the pedal stroke increases.

Therefore, check valves 60 and 61 are provided in the passages 35 and 54, respectively. These check valves 60 and 61 allow only the flow of the brake fluid from the passages 33 and 52 to the passages 27 and 46, respectively. Further, each of the solenoid on-off valves 34, 53
Each passage 33, 52 on the M / C4 side and each passage 35, 54 on the passage 27, 46 side from each check valve 60, 61.
Are connected by respective passages 62 and 63, respectively. The passages 62 and 63 are provided with normally-closed electromagnetic on-off valves 64 and 65, respectively. These electromagnetic on-off valves 64 and 65 are both operated and opened during TRC control, vehicle stability control, BA control, and automatic brake control.

In the brake system 1 of the third example, in order to control the M / C piston stroke, the brake fluid on the M / C4 side from each of the on-off valves 14 and 16 with a relief valve is supplied to each of the absorption chambers 32a and 51a. In this case, the brake fluid on the M / C 4 side is introduced into each of the absorption chambers 32a and 51a by the controller controlling the opening and closing of the electromagnetic on-off valves 34 and 53 of the respective liquid introducing means in the same manner as described above.

When the brake fluid introduced into the absorption chambers 32a, 51a returns to the branch points A, B as described above, the controller only drives the pumps 31, 50, and the electromagnetic opening / closing is performed. The valves 34, 53, 64, 65 are not controlled to open or close. By controlling the driving of these pumps 31 and 50 by PWM control or the like, the brake fluid introduced into each of the absorption chambers 32a and 51a is supplied to each of the check valves 60 and 50, respectively.
It returns to each branch point A, B through 61. As described above, each of the pumps 31 and 50 constitutes the return pump of the present invention.

Further, during the TRC control, the vehicle stability control, the BA control, and the automatic brake control, the controller sets the on-off valves 14 and 16 with relief valves to the relief valve position and controls each electromagnetic opening and closing, as in the above-described embodiments. Valve 64, 6
5 is opened, and the pumps 31 and 50 are driven. Thereby, the brake fluid is sucked from the reservoir 12 of the M / C 4 by the respective pumps 31 and 50, and the respective W / Cs 7, 8,
9 and 10, the brakes are activated.

At this time, the opening and closing of each of the solenoid on-off valves 34 and 53 is not controlled. Particularly, during the BA control, the flow from the passages 62, 63 to the absorption chambers 32a, 51a is blocked by the check valves 60, 61, so that an increase in the pedal stroke can be prevented in the BA control. Thus, each check valve 60, 61 constitutes the absorption inhibiting means of the present invention. Other configurations, other operations, and other operational effects of the brake system 1 of the third example are the same as those of the first example.

FIG. 4 is a view showing a fourth example of the embodiment of the brake system according to the present invention. In the second example described above, the brake fluid discharged to the ABS reservoirs 23 and 42 is recirculated by the pumps 31 and 50, and then the brake fluid stored in the absorption chambers 32a and 51a is recirculated. In order to ensure the pressure reduction control, each of the passages 35 and 54 is provided with each of the solenoid on-off valves 36 and 55. In the third example described above, in order to prevent an increase in the pedal stroke during the BA control, the passages 62 and 63 and the check valves 60 and 61 are provided to constitute absorption inhibition means. However, these second and third examples are provided with only one of the means for circulating the brake fluid in the ABS reservoir first and the means for inhibiting absorption. On the other hand, in the brake system 1 of the fourth example, as shown in FIG.
From the branch point between the second and each passage 35, 54, each absorption chamber 32a, 5
It is provided in each of the passages 33 and 52 on the 1a side.

In the brake system 1 of the fourth example configured as described above, the M / C
When the brake fluid on the fourth side is introduced into each of the absorption chambers 32a and 51a, each of the electromagnetic on / off valves 36 and 55 is opened, and each of the electromagnetic picture on / off valves 34 and 53 as the liquid introducing means is controlled by, for example, PWM control. Opening / closing is controlled.

When the brake fluid stored in each of the absorption chambers 32a, 51a is recirculated, each of the electromagnetic on-off valves 36, 55 is started when the drive control such as the PWM control of each of the return pumps 31, 50 is started. Are closed, and when it is determined from the above estimation that the brake fluid in the ABS reservoirs 23 and 42 has substantially circulated, each of the electromagnetic on-off valves 3
6, 55 is opened to recirculate the brake fluid introduced into each of the absorption chambers 32a, 51a.

Further, at the time of BA control, each of the electromagnetic on-off valves 3
4, 53 opened, M / C4 brake fluid
The fluid is sucked by the pumps 31 and 50 via the pumps 5 and 54 and discharged toward the branch points A and B. At this time, the brake fluid of the M / C 4 is kept closed while the solenoid valves 36 and 55 are closed. Is not introduced into each of the absorption chambers 32a and 51a.

As described above, the pressure reducing control in the ABS control can be surely performed by the electromagnetic on-off valves 36 and 55, and the pedal stroke can be prevented from increasing in the BA control. , And can be configured at low cost.

The liquid return means of the fourth example uses a drive control such as a PWM control for the pumps 31, 50 as described above. By controlling the opening and closing of each of the electromagnetic on-off valves 36 and 55 by PWM control or the like, it is possible to use a liquid return means. Other configurations, other operations, and other operational effects of the brake system 1 of the third example are the same as those of the first example.

FIG. 5 is a diagram showing a fifth example of the embodiment of the brake system according to the present invention. In each of the first and fourth examples, the amount of the brake fluid introduced into each of the absorption chambers 32a and 51a is estimated based on the opening control time of the electromagnetic on-off valves 34 and 53. 5, in the brake system 1 shown in FIG. 5, in the brake system 1 shown in FIG. 4, stroke sensors 57 and 58 for detecting respective piston strokes of the respective absorption pistons 32b and 51b of the respective absorption chambers 32a and 51a are provided. Have been. These stroke sensors 57, 58 are both connected to the controller described above.

Then, based on the information on the piston stroke of each absorption piston 32b, 51b of each absorption chamber 32a, 51a detected by each stroke sensor 57, 58, the controller operates the brake introduced into each absorption chamber 32a, 51a. The amount of liquid introduced is detected. Further, the controller controls each of the electromagnetic on-off valves 34 and 53 based on the detected brake fluid introduction amount by PWM control or the like. Each of the stroke sensors 57 and 58 constitutes a brake fluid introduction amount detecting means of the present invention.

According to the brake system 1 of the fifth example, the amount of brake fluid introduced into each of the absorption chambers 32a and 51a can be detected more accurately than in the first and fourth examples. By controlling the electromagnetic on / off valves 34 and 53 by the PWM control or the like based on the introduced brake fluid introduction amount, the M / C piston stroke and the pedal stroke are controlled by the electromagnetic on / off valves as in the first and fourth examples. Control can be performed more accurately as compared with the control based on the calculated open control time in which the control by the PMW control or the like is performed. . Other configurations, other operations, and other operational effects of the brake system 1 of the fifth example are the same as those of the fourth example. Note that each of the stroke sensors 57 and 58 is the first
Examples, the second example and the third example can also be provided.

FIG. 6 is a diagram showing a sixth example of the embodiment of the brake system according to the present invention. In each of the first to fifth examples described above, the controller uses the pressure sensor 5
Although the M / C piston stroke, that is, the pedal stroke in the single friction brake system is calculated from the M / C pressure detected in step 6, in the brake system 1 of the sixth example, as shown in FIG. In the brake system 1 shown, a stroke sensor (corresponding to a stroke detecting means of the present invention) 59 for detecting a stroke of the input shaft 13 of the negative pressure booster 3 is provided. This stroke sensor 59 is connected to the above-mentioned controller.

The controller detects a pedal stroke (corresponding to the operation stroke of the present invention) based on the information on the stroke of the input shaft 13 detected by the stroke sensor 59, and uses the detected pedal stroke to control each of the electromagnetic switching valves. 34, 36, 53 and 55 are controlled.

According to the brake system 1 of the sixth example, since the pedal stroke can be detected more accurately than in the first to fifth examples, the M / C piston stroke and the pedal stroke can be controlled more accurately. become able to. The M / C is controlled by controlling the solenoid on-off valves 34, 36, 53 and 55 based on the M / C pressure and the pedal stroke detected by the stroke sensor 59.
The relationship between pressure and pedal stroke can be adjusted to be optimal.

The other configuration, other operations, and other operational effects of the brake system 1 of the sixth example are the same as those of the fourth example. Note that the stroke sensor 59 is a first example, a second example,
The stroke sensors 57 and 58 of the fifth example can be provided in the third example and the fifth example, respectively.
Examples can also be provided.

FIG. 7 is a view showing a seventh example of the embodiment of the brake system according to the present invention. In each of the first to sixth examples described above, each of the liquid introduction means and each of the liquid return means is located between the M / C 4 and each of the absorption chambers 32a and 51a to control the movement of the brake fluid. However, in the brake system 1 of the seventh example, each of the electromagnetic on-off valves 34, 36, 53, 5 in the brake system 1 of the fourth example shown in FIG.
5 is not provided.

The back pressure side of each absorption piston 32b, 51b of each absorption chamber 32a, 51a is connected to the back pressure chamber 32d, 51b.
d is provided. Each of the back pressure chambers 32d and 51d has a pump (corresponding to a return pump of the present invention) 7.
4 supplies the brake fluid sucked and discharged from the reservoir (corresponding to the low pressure chamber of the present invention) 12. That is, each absorption piston 32b, 51b
The pump discharge pressure of the pump 74 acts on the back pressure side. Further, the back pressure side of each of the absorption pistons 32b, 51b of each of the absorption chambers 32a, 51a can be connected to the reservoir 12 by a normally closed electromagnetic on-off valve 75. Other configurations of the brake system 1 of the third example are the same as those of the first example.

In the brake system 1 of the seventh example configured as described above, the brake fluid from the M / C 4 is supplied to each of the absorption chambers 32a and 51a in order to control the pedal stroke.
Controller, the controller sets the solenoid on-off valve 75 to PW
Open / close control is performed by M control or the like. Then, the brake fluid from the M / C 4 is introduced into each of the absorption chambers 32a and 51a, and the pedal stroke is controlled in the same manner as in each of the above-described examples.

When returning the brake fluid introduced into each of the absorption chambers 32a and 51a to the M / C 4, the controller closes the electromagnetic on-off valve 75 and drives the pump 74. Then, each back pressure chamber 32 of each absorption chamber 32a, 51a
The brake fluid sucked by the pump 74 from the reservoir 12 is discharged to d and 51d, respectively, and the discharge pressure of the pump 74 acts on the back pressure side of each of the absorption pistons 32b and 51b.

As a result, the brake fluid introduced into each of the absorption chambers 32a and 51a is supplied to the pump 74 on the back pressure side.
Of each absorption piston 32 urged by the discharge pressure of
b, 51b return to M / C4. As described above, in the brake system 1 of the seventh example, the liquid introducing means is constituted by the electromagnetic on-off valve 75, and the liquid returning means is constituted by the pump 74.

According to the brake system 1 of the seventh example, by controlling the rotation speed of the pump 74, a desired amount of brake fluid can be recirculated to each of the branch points A and B. Further, since the fluid introduction means and the fluid return means are provided independently of the brake fluid pressure control device 11 such as ABS, the brake control by the brake fluid pressure control device 11 is affected when the pedal stroke is controlled by the fluid introduction means and the fluid return means. Will not give. Other operations and other effects of the brake system 1 of the seventh example are the same as those of the first example. Note that each of the stroke sensors 57 and 58 of the fifth example and the stroke sensor 59 of the sixth example
Examples can also be provided.

FIG. 8 is a diagram showing an eighth example of the embodiment of the brake system according to the present invention. In each of the first to seventh examples described above, each of the on-off valves 1
The brake fluid on the M / C4 side of each of the absorption chambers 32a, 5
1a, the pedal stroke is controlled. In the brake system 1 of the ninth example, the brake fluid at each branch point A, B on the W / C side of each of the on-off valves 14, 16 with a relief valve is controlled. Is introduced into each of the absorption chambers 32a and 51a,
Controlling the pedal stroke. Other configurations of the brake system 1 of the eighth example are the same as those of the seventh example.

In the brake system 1 of the eighth example configured as described above, the brake fluid from the M / C 4 is supplied to each of the absorption chambers 32a and 51a to control the pedal stroke.
As in the seventh example, the controller controls the opening and closing of the electromagnetic on-off valve 75 by PWM or the like. Then M
/ C4 is supplied to each absorption chamber 32a, 5
1a, the pedal stroke is controlled in the same manner as in the above-described respective examples.

Each of the pressure reducing valves 24, 26, 43, 45
When the brake fluid is discharged to the ABS reservoirs 23 and 42 from
16 is set to the relief valve position, the pumps 31 and 50 of the brake fluid pressure control device are drive-controlled by PWM control or the like to recirculate to the respective branch points A and B, and the electromagnetic on-off valve 75 is controlled by PWM control or the like. The brake fluid circulated to the branch points A and B by opening / closing control is introduced into the absorption chambers 32a and 51a, respectively. At this time, the solenoid on-off valve 75 is controlled so as to have a passage resistance that is equal to or higher than the hydraulic pressure M / C pressure at each of the branch points A and B and lower than the relief hydraulic pressure of each on-off valve with a relief valve.
When the brake fluid in the BS reservoir is completely recirculated and the discharge flow rate of each of the pumps 31 and 50 is exhausted, the solenoid on-off valve 75 is closed quickly, so that the pedal stroke does not fluctuate and unpleasant vibration such as pump discharge pulsation is applied to the pedal. Transmission is also prevented.

Further, when returning the brake fluid introduced into each of the absorption chambers 32a and 51a to each of the branch points A and B, the controller closes the solenoid on-off valve 75 and switches the return pump 74 to P
When the drive is controlled by the WM control or the like, the discharge pressure of the pump 74 acts on the back pressure side of each of the absorption pistons 32b and 51b as in the seventh example, and the brake fluid is returned to the branch points A and B.

At this time, the controller sets the on-off valves 14 and 16 with relief valves to the relief valve position and sets the pressure-intensifying valves 18, 19, 37 and 38 to the respective branch points A and B.
Is controlled so that the passage pressure becomes equal to or higher than the M / C pressure and lower than the relief hydraulic pressure of each on-off valve with a relief valve. Therefore, the pedal stroke does not fluctuate and unpleasant vibration such as pump discharge pulsation is prevented from being transmitted to the pedal. 8th
Other operations and other effects of the example brake system 1 are the same as those of the seventh example. The stroke sensors 57 and 58 of the fifth example and the stroke sensor 5 of the sixth example
9 can also be provided in the eighth example.

FIG. 9 is a view showing a ninth embodiment of the brake system according to the present invention. In the first to eighth examples described above, the brake fluid stored in each of the absorption chambers 32a and 51a is circulated by the respective return pumps 31, 50 and 74. However, in the brake system 1 of the ninth example, The brake fluid is returned by the urging forces of the springs 32c, 51c for urging the pistons 32b, 51b of the absorption chambers 32a, 51a.

In the brake system 1 of the ninth example, the passages 66, 67 branching from the passages 5a, 6b always communicating with the branch points A, B, respectively, are provided. Are each absorption chamber 32a,
51a. In addition, these passages 66, 6
7 are provided with normally closed electromagnetic on-off valves 68 and 69, respectively.

Furthermore, in the brake system 1 of the ninth example,
The passages 5 and 6 on the M / C 4 side of the on-off valves 14 and 16 with relief valves, the passage 27 between the check valves 29 and 30 and the passage 46 between the check valves 48 and 49 are each a passage 70, These passages 70, 71 are connected to normally closed solenoid on-off valves 72, 7, respectively.
3 are provided. Brake system 1 of the ninth example
The other configuration is the same as that of the fourth example.

In the ninth example of the brake system 1 configured as described above, the brake fluid from the M / C 4 is supplied to each of the absorption chambers 32a and 51a to control the pedal stroke.
The controller sets the relief valve positions of the on-off valves 14 and 16 with relief valves, closes the pressure-intensifying valves 18, 19, 37 and 38, and also controls the on-off valves 68, 69 and 72. , 73, and further, each pump 31,
50 is driven and controlled by PWM control or the like. Then, the brake fluid from the M / C 4 is introduced into each of the absorption chambers 32a and 51a as in each of the above-described examples, and the pedal stroke is controlled as in each of the above-described examples. In that case, each absorption chamber 32
Since the brake fluid is introduced into a and 51a by the pumps 31 and 50, the brake fluid having a pressure higher than the M / C pressure is stored. Each pump 31 of the ninth example,
Reference numeral 50 also constitutes the liquid introduction pump of the present invention.

When returning the brake fluid introduced into each of the absorption chambers 32a, 51a to each of the branch passages 5a, 5b, 6a, 6b, the controller operates the on-off valve 14 with a relief valve,
16 is set to the relief valve position, and each solenoid on-off valve 68, 6
9 is opened, the respective solenoid on-off valves 72, 73 are closed, and the respective pumps 31, 50 are stopped. Further, the pressure increasing valves 18,1
When opening / closing control is performed on the 9, 37, 38 by PWM control or the like so that the target W / C pressure becomes the target W / C pressure, the brake fluid introduced into each of the absorption chambers 32a, 51a absorbs each of the absorption fluids urged by each of the springs 32c, 51c. The pistons 32b, 51b return to the respective branch passages 5a, 5b, 6a, 6b. At this time, since the brake fluid having a higher pressure than the M / C pressure is stored in each of the absorption chambers 32a and 51a, the brake fluid of the M / C4 flows into each of the branch passages 5a, 5b, 6a and 6b. Because there is no pedal stroke does not fluctuate. Further, since no pump is used for the liquid return means, unpleasant vibrations such as pump discharge pulsation are not transmitted to the pedal.

Further, during the TRC control, the vehicle stability control, the BA control, and the automatic brake control, the controller sets the relief valve-equipped on-off valves 14 and 16 to the relief valve position and controls each electromagnetic on-off operation, as in the above-described embodiments. Valves 72,7
3 is opened, and the pumps 31 and 50 are driven. Thereby, the brake fluid is sucked from the reservoir 12 of the M / C 4 by the respective pumps 31 and 50, and the respective W / Cs 7, 8,
9 and 10, the brakes are activated.

At this time, the controller operates the electromagnetic on-off valves 6
By closing 8,69, each absorption chamber 3 for brake fluid
Since the inflow to 2a and 51a is prevented, TRC control,
The vehicle stability control, the BA control or the automatic brake control is not affected by the absorption chambers 32a and 51a. In particular, in BA control, an increase in pedal stroke can be prevented. Other operations and other effects of the ninth example of the brake system 1 are the same as those of the fourth example. Each of the stroke sensors 57 and 58 of the fifth example and the stroke sensor 59 of the sixth example can be provided also in the ninth example.

FIG. 10 is a diagram showing a tenth example of the embodiment of the brake system according to the present invention. The above-mentioned first
In each of the eighth to eighth examples, the electric control system in which the M / C piston stroke (that is, the pedal stroke) control at the time of the regenerative cooperative braking is performed by the electromagnetic on-off valve. This is a mechanical control method in which M / C piston stroke control during regenerative braking is performed using M / C pressure, W / C pressure, and a spring. In the above-described eighth example, the brake fluid at each of the branch points A and B is introduced into each of the absorption chambers 32a and 51a. However, in the brake system 1 of the tenth example, the aforementioned As in the first to third examples, the brake fluid on the M / C4 side of each of the on-off valves 14 and 16 with a relief valve is introduced.

That is, as shown in FIG. 10, in the brake system 1 of the tenth example, the hydraulic pressure control switching valve 76
2 is provided. By this hydraulic pressure control switching valve 76,
The absorption chamber 51a is provided with the on-off valves 14 and 16 with a relief valve and the M / C.
4 can be connected to the passage 6.

The hydraulic pressure control switching valve 76 comprises a three-position three-way valve. The first position I connects the absorption chamber 51a to the passage 6, ie, the M / C 4, and shuts off the ABS reservoir 42. Adjacently, M / C4 and AB
A second position II to shut off from any of the S reservoirs 42;
Adjacent to the second position II, the absorption chamber 51a is connected to the ABS reservoir 42 via a check valve 77 and the M / C
4 and a third position III at which the light is blocked from the third position III. The hydraulic pressure control switching valve 76 controls the first pressure by the M / C pressure Pm
The position I is urged in the set direction, and the W / C pressure Pw and the spring 51c are urged in the direction in which the third position III is set. The spring 51c is connected to the hydraulic pressure control switching valve 7
6 is always energized).

In this case, the hydraulic pressure control switching valve 76 is
The acting force due to the pressure Pm (Pm · A1; A1 is the pressure receiving area of the M / C pressure Pm of the fluid pressure control switching valve 76) is the acting force due to the W / C pressure Pw (Pw · A2; A2 is the fluid pressure control switching valve 76). W
/ C pressure Pw) and the urging force (Fs) of the spring 51c (Pw · A2 + Fs).
m · A1> Pw · A2 + Fs), the first position is set, and the acting force by the M / C pressure Pm is equal to the resultant force of the acting force by the W / C pressure Pw and the urging force of the spring 51c (Pm · A1). = Pw · A2 + Fs), the second position is set, and the acting force due to the M / C pressure Pm is changed to the W / C pressure Pw.
Is smaller than the combined force of the acting force of the spring 51c and the urging force of the spring 51c (Pm · A1 <Pw · A2 + Fs), the third position is set. Therefore, the hydraulic pressure control switching valve 76 is normally set to the third position as shown by the urging force (Fs) of the spring 51c when it is not operated, and shuts off the absorption chamber 51a from the M / C 4 and the ABS. Connected to reservoir 42. Other configurations of the brake system 1 of the tenth example are the same as those of the eighth example.

In the brake system 1 of the tenth example configured as described above, when the M / C 4 generates the M / C pressure by depressing the brake pedal 2 as in each of the above-described examples, when the regenerative cooperative braking is operated. These M / C pressures are reduced and supplied to W / Cs 7, 8, 9, and 10, respectively. At this time, the M / C pressure Pm and the W / C pressure Pw reduced by the regenerative cooperation act on the hydraulic control switching valve 76, respectively. During the period of Pm · A1 <Pw · A2 + Fs, the hydraulic pressure control switching valve 76 is set to the illustrated third position III, and the brake fluid is not introduced into the absorption chamber 51a.

The M / C pressure rises and Pm · A1> Pw · A
At 2 + Fs, the hydraulic pressure control switching valve 76 is set to the first position I, and the absorption chamber 51a is connected to the M / C4. Then, the brake fluid from the M / C 4 is introduced into the absorption chamber 51a, and the M / C piston stroke (that is, the pedal stroke) control during the regenerative cooperative braking is performed as in the above-described respective examples. When the brake fluid from the M / C 4 is introduced into the absorbing chamber 51a, the absorbing piston 51b rises in the drawing, so that the urging force Fs of the spring 51c gradually increases.

When Pm · A1 = Pw · A2 + Fs and the forces acting on the hydraulic pressure control switching valve 76 are balanced, the hydraulic pressure control switching valve 76 is set to the second position II and the absorption chamber 51a is set.
Is shut off from both the M / C 4 and the ABS reservoir 42. Thereby, the introduction of the brake fluid into the absorption chamber 51a is stopped, and the introduced brake fluid is stored in the absorption chamber 51a. As described above, when the regenerative braking is operated, the amount of the brake fluid introduced into the absorption chamber 51a is controlled by the M / C pressure and the W / C pressure, so that the M / C piston stroke (pedal stroke). Can be made the same as in the case of a single friction brake system.

In this case, when the total braking force Ft reaches the required braking force Ft ₀ , the necessary W / C pressure is reduced as described above, and the hydraulic pressure control switching valve 76 is again moved to the first position.
When set to I, the absorption chamber 51a is connected to the M / C4,
The brake fluid from the M / C 4 is further introduced into the absorption chamber 51a. As a result, the brake pedal 2 is prevented from being pushed back as described above, and the pedal stroke can be made the same as in the case of the single friction brake system. When the M / C pressure is reduced by the introduction of the brake fluid of the M / C 4 into the absorption chamber 51a and the force acting on the hydraulic pressure control switching valve 76 is balanced, the hydraulic pressure control switching valve 76 returns to the second position II. Is set.

When the regenerative braking force starts to decrease,
As described above, the required W / C pressure increases, and Pm · A1 <Pw
When A2 + Fs, the hydraulic pressure control switching valve 76 is set to the third position III shown in the drawing, and the absorption chamber 51a is connected to the ABS reservoir 42. Then, the brake fluid in the absorption chamber 51a is discharged to the ABS reservoir 42 via the check valve 77, and further circulated to the branch point B on the M / C4 side by the pump 50 driven by the controller. This prevents the pedal stroke from being extended as described above.

Further, in a state where the hydraulic pressure control switching valve 76 is set at the second position II, the M / C pressure decreases and Pm · A1
<Pw · A2 + Fs, the hydraulic pressure control switching valve 76 is also set to the third position III shown
a is connected to the ABS reservoir 42, and similarly, the brake fluid in the absorption chamber 51a is circulated by the pump 50 toward the branch point B on the M / C 4 side. This pump 50 constitutes the return pump of the present invention. In the brake system on the side of the passage 5, the same M / C piston stroke (pedal stroke) control is performed as described above.

As described above, in the brake system 1 of the tenth example, the liquid introducing means and the liquid returning means are integrated into one, and these liquid introducing means and the liquid returning means are shared by the common hydraulic pressure control switching valve. (The hydraulic pressure control switching valve of the brake system on the passage 6 side is indicated by reference numeral 76).

According to the brake system 1 of the tenth embodiment, since the pedal stroke control is performed by the mechanical control system, the pedal stroke can be controlled more reliably than in the first to eighth embodiments, and the pedal stroke can be controlled. Control reliability can be improved. Further, by performing the pedal stroke control by the mechanical control method, the control of the controller becomes easier.

Further, since the amount of brake fluid introduced into the absorption chamber 51a is determined by a mechanical balance such as the M / C pressure, the W / C pressure, and the spring force of the spring 51c, complicated control is not required. The pedal stroke control can be easily performed. In addition, since there is no need to physically change the controller of the existing brake fluid pressure control device 11, pedal stroke control can be realized at low cost. Other operations and other effects of the brake system 1 of the tenth example are the same as those of the eighth example.

FIG. 11 is a diagram showing an eleventh example of the embodiment of the brake system according to the present invention. The above-mentioned first
In the zero example, the hydraulic control switching valve 76 including a three-position three-way valve is provided. However, in the brake system 1 of the eleventh example,
A hydraulic pressure control switching valve composed of a two-position two-way valve is provided. That is, as shown in FIG. 11, in the brake system 1 of the eleventh example, the passage 52 is provided with a hydraulic pressure control switching valve 78 composed of a normally-closed on-off valve, a normally-open rapid-operation on-off valve 79, and an orifice 80. ing.

The hydraulic pressure control switching valve 78 is provided in the passage 52, and the quick-acting on / off valve 79 is provided in the passage 52 on the M / C4 side than the hydraulic pressure control switching valve 78. Further, the orifice 80 is provided with M
/ C4 side passage 52 is provided.

When the hydraulic pressure control switching valve 78 is opened, the M / C
4 and the absorption chamber 51a are set to be connectable. The hydraulic pressure control switching valve 78 is connected to the M / C pressure Pm
The spring 51c is urged in the closing direction by the W / C pressure Pw and the spring 51c (the spring 51c always operates the hydraulic pressure control switching valve 78). Energized).

In this case, the hydraulic pressure control switching valve 78 is
The acting force due to the pressure Pm (Pm · A3; A3 is the pressure receiving area of the M / C pressure Pm of the fluid pressure control switching valve 78) is the acting force due to the W / C pressure Pw (Pw · A4; A4 is the fluid pressure control switching valve 78). W
/ C pressure Pw) and the urging force (Fs) of the spring 51c (Pw · A4 + Fs).
Open when m · A3> Pw · A4 + Fs) and M / C
The acting force due to the pressure Pm is equal to or less than the combined force of the acting force due to the W / C pressure Pw and the urging force of the spring 51c (Pm · A3 ≦ Pw
-When A4 + Fs), it is closed. Therefore, the hydraulic pressure control switching valve 78 is set to a closed position as shown by the urging force (Fs) of the spring 51c when not operating, and shuts off the absorption chamber 51a from the M / C 4.

The quick-acting on-off valve 79 is normally open and
/ C4 and the hydraulic pressure control switching valve 78 are connected. This quick-acting on-off valve 79 is
The valve is biased in the closing direction by the M / C pressure Pm on the / C4 side, and is opened in the opening direction by the M / C pressure Pm between the hydraulic pressure control switching valve 78 and the quick-acting on-off valve 79. It is getting energized. Although not shown, the quick-acting on-off valve 79 is always urged to open by a small urging force such as a spring, and is opened when not in operation.

When the sudden actuation such as sudden braking is performed, the M / C pressure is reduced by the orifice 80, and the sudden actuation on-off valve 79 is located downstream of the sudden actuation on-off valve 79 (the hydraulic pressure control switching valve 7).
8) is closed due to the differential pressure of the hydraulic pressure acting on the quick-acting on-off valve 79, which is generated due to the delay of the rise of the hydraulic pressure, and the M / C pressure is prevented from being applied to the hydraulic pressure control switching valve 78. During operation, the hydraulic pressure control switching valve 78 is not operated. The reason why the hydraulic pressure control switching valve 78 is not operated at the time of sudden operation is that the response of the W / C side caused by the influence of the resistance of the passage 6 at the time of sudden operation causes a delay in M / C.
A pressure difference occurs between the / C pressure and the W / C pressure, and despite the fact that the pedal stroke adjustment is not based on the reduction of the W / C pressure in the regenerative braking, the hydraulic pressure control switching valve 78 malfunctions and the M / C4 This is to prevent the increase in the W / C pressure from being delayed due to the introduction of the brake fluid from the intake chamber 51a into the absorption chamber 51a. The quick-acting on-off valve 79 and the orifice 80 are not necessarily provided in the present invention, and may be omitted.

Further, in the brake system 1 of the eleventh example, a normally open on-off valve 81 is provided in the passage 54, and this on-off valve 81 is connected to the piston 42a of the ABS reservoir 42.
The opening and closing are controlled by the stroke. That is, when a predetermined amount of brake fluid is not stored in the ABS reservoir 42 and the piston 42a is in the raised position in the drawing, the on-off valve 81
2a. At this time, the absorption chamber 51a is connected to the suction side of the pump 50 via the ABS reservoir 42. AB
When the brake fluid is discharged into the S reservoir 42 and stored in a predetermined amount, the piston 42a strokes downward in the drawing, and the on-off valve 81 closes. At this time, the absorption chamber 51a is shut off from the suction side of the ABS reservoir 42 and the pump 50. This on-off valve 81 constitutes the reservoir priority valve of the present invention. Other configurations of the brake system 1 of the eleventh example are the same as those of the tenth example.

In the brake system 1 of the eleventh example configured as described above, when the M / C 4 generates the M / C pressure by depressing the brake pedal 2 as in the above-described respective examples, when the regenerative braking is activated, These M / C pressures are reduced and supplied to W / Cs 7, 8, 9, and 10, respectively. At this time, the M / C pressure Pm is transmitted through the orifice 80 and the quick opening / closing valve 79, and the hydraulic pressure control switching valve 78
And W / C depressurized by regenerative cooperation
The pressure Pw acts on the hydraulic control switching valve 78. Pm ・ A3 <
During Pw · A4 + Fs, the hydraulic pressure control switching valve 78 is closed as shown, and no brake fluid is introduced into the absorption chamber 51a.

The M / C pressure rises and Pm · A3> Pw · A
At 4 + Fs, the hydraulic pressure control switching valve 78 is opened, and the absorption chamber 51a is connected to the M / C4. Then, the brake fluid from the M / C 4 is introduced into the absorption chamber 51a, and the M / C piston stroke (that is, the pedal stroke) control during the regenerative cooperative braking is performed as in the above-described respective examples. Further, the brake fluid introduced via the hydraulic pressure control switching valve 78 is also introduced into the ABS reservoir 42 through the passage 54 and the opening / closing valve 81, and the introduced brake fluid causes the piston 42a of the ABS reservoir 42 to be introduced. Immediately strokes downward, so that the on-off valve 81 closes immediately. As a result, the brake fluid is no longer introduced into the ABS reservoir 42 and most of the brake fluid is absorbed by the absorption chamber 51a.
Will be stored in.

When the pump 50 is driven, the ABS reservoir 4
When the brake fluid of the second is almost discharged, the piston 42
Since a moves upward, the on-off valve 81 opens. Then, the brake fluid in the absorption chamber 51a is sucked by the pump 50 through the on-off valve 81 and the ABS reservoir 42, and is returned to the branch point B. At this time, the absorption chamber 5
Since the brake fluid 1a is continuously sucked by the pump 50, the brake fluid hardly accumulates in the ABS reservoir 42, so that the piston 42a hardly strokes downward and the on-off valve 81 does not close. This pump 50 constitutes the return pump of the present invention.

When the brake fluid from the M / C 4 is introduced into the absorbing chamber 51a, the absorbing piston 51b rises in the drawing, so that the urging force Fs of the spring 51c gradually increases. When Pm · A3 = Pw · A4 + Fs and the forces acting on the hydraulic pressure control switching valve 78 are balanced, the hydraulic pressure control switching valve 78 is closed again, and the absorption chamber 51a is shut off from the M / C4. Thereby, the introduction of the brake fluid into the absorption chamber 51a is stopped, and the introduced brake fluid is stored in the absorption chamber 51a. Thus, in the eleventh example, as in the tenth example described above, the amount of the brake fluid of M / C4 introduced into the absorption chamber 51a is changed to the M / C pressure and the W / C pressure during the regenerative braking operation. , The M / C piston stroke (pedal stroke) can be made the same as in the case of the single friction brake system.

When Pm · A3 <Pw · A4 + Fs due to an increase in the W / C pressure or a decrease in the M / C pressure, the hydraulic pressure control switching valve 78 is closed and the absorption chamber 51a is closed.
/ C4.

As described above, in the brake system 1 of the eleventh example, the fluid introduction means is provided with the fluid pressure control switching valve (the fluid pressure control switching valve of the brake system on the passage 6 side is indicated by reference numeral 78). The liquid return means includes an on-off valve (the on-off valve of the brake system on the passage 6 is indicated by reference numeral 81) and a pump (the pump on the brake system on the passage 6 side is indicated by reference numeral 50).

According to the brake system 1 of the eleventh example, the piston 42a of the ABS reservoir 42 is
The opening / closing valve 81 that is controlled to open and close by the stroke is provided, so that the liquid return means can be configured simply and inexpensively. Also, ABS control is performed during the regenerative cooperative braking operation,
When the brake fluid of the W / C 9 is drained from the ABS reservoir 42, the on-off valve 82 closes because the piston 42a strokes downward. Thus, the pressure reduction control of the ABS control can be reliably performed without being affected by the regenerative cooperative brake. Other operations and other effects of the brake system 1 of the eleventh example are the same as those of the tenth example.

In each of the first to eleventh examples, the W / C pressure is estimated. However, the W / C pressure is directly detected by the pressure sensor as in the first example. You can also. With this configuration, the W / C pressure can be accurately detected, so that the regenerative cooperative braking can be performed more accurately.

Further, without being limited to the negative pressure booster 3, other boosters such as a hydraulic booster and a booster using air (compressed air) can be used. By omitting the force device and depressing the brake pedal 2,
It is also possible to operate the M / C piston directly.

Further, in the above-described first to eleventh examples,
All use a brake control device that can control the W / C pressure higher than the M / C pressure for TRC control, vehicle stability control, BA control, automatic brake control, etc. However, a brake control device that can only control the W / C pressure to be lower than the M / C pressure, such as ABS control, can be used. In that case, especially in the seventh example, the tenth example and the eleventh example, each passage 70, 71, each electromagnetic on-off valve 72, 73,
Since the on-off valves with relief valves 14 and 16 and the check valves 30 and 49 can be omitted, the structure can be simplified and the structure can be reduced.

[0147]

As is apparent from the above description, according to the brake system of the present invention, when the brake fluid pressure of the brake cylinder is reduced during the cooperative braking, the brake fluid of the master cylinder is introduced into the fluid introducing means. Therefore, the operation stroke of the brake operation member is not changed during the operation stroke of the brake operation member, and can be the same as the operation stroke of the friction brake system alone. Thereby, the operation feeling of the operation member can be favorably maintained during the regenerative cooperative braking. In particular, when the operation member is operated (that is, when the operation amount is increased), when the master cylinder pressure is limited and supplied to the brake cylinder by the decrease in the brake fluid pressure of the brake cylinder in the regenerative cooperative braking operation,
Since the conventional feeling of stepping on the plate can be eliminated, the operation feeling can be further improved.

In addition, since the absorbing means, the liquid introducing means, and the liquid returning means are provided independently of the brake hydraulic pressure control device, the control of the brake hydraulic pressure of the brake cylinder at the time of the regenerative cooperative braking is affected. Without this, the operation stroke of the operation member can be controlled. Therefore, the operation stroke can be more accurately and easily controlled in accordance with the required braking force at the time of the regenerative cooperative braking.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a first example of an embodiment of a brake system according to the present invention.

FIG. 2 is a diagram schematically showing a second example of the embodiment of the present invention.

FIG. 3 is a diagram schematically showing a third example of the embodiment of the present invention.

FIG. 4 is a diagram schematically showing a fourth example of the embodiment of the present invention.

FIG. 5 is a diagram schematically showing a fifth example of the embodiment of the present invention.

FIG. 6 is a diagram schematically showing a sixth example of the embodiment of the present invention.

FIG. 7 is a diagram schematically showing a seventh example of the embodiment of the present invention.

FIG. 8 is a diagram schematically showing an eighth example of the embodiment of the present invention.

FIG. 9 is a diagram schematically showing a ninth embodiment of the present invention.

FIG. 10 is a diagram schematically showing a tenth example of an embodiment of the present invention.

FIG. 11 is a diagram schematically showing an eleventh example of an embodiment of the present invention.

FIG. 12 is a diagram showing a relationship between a pedal depression force and a braking force.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Brake system, 2 ... Brake pedal, 3 ... Negative pressure booster, 3 ... Master cylinder (M / C), 5, 6 ... Passage, 7, 8, 9, 10 ... Wheel cylinder (W / C) , 1
DESCRIPTION OF SYMBOLS 1 ... Brake fluid pressure control device, 12 ... Reservoir, 13 ... Input shaft of negative pressure booster 3, 14, 16 ... On-off valve with relief valve, 18, 19, 37, 38 ... Pressure increasing valve, 23, 42 ... A
BS reservoir, 24, 26, 43, 45 ... pressure reducing valve, 3
1,50 ... pump, 32,51 ... absorbing means, 32a, 51
a: absorption chamber, 32b, 51b: absorption piston, 34, 3
6,53,55,64,65,68,69,72,73,75 ...
Solenoid on-off valve, 56 ... Pressure sensor, 57, 58, 59 ... Stroke sensor, 74 ... Pump, 76, 78 ... Hydraulic pressure control switching valve, 79 ... Rapid operation on-off valve, 80 ... Orifice, 81,
82 ... On-off valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D046 BB03 BB28 BB29 CC02 CC06 HH00 HH02 HH16 LL23 LL29 LL37 LL41 LL47 LL50 5H115 PA01 PG04 PI16 PO17 PU01 QE10 QI04 QI12 QI24 TI05 TU04

Claims (19)

[Claims] 1. A friction brake system comprising a regenerative brake system and a friction brake system. The friction brake system includes a brake operation member for performing a brake operation, a master cylinder for generating a master cylinder pressure by the brake operation of the brake operation member. A brake cylinder that generates a friction braking force, and a brake fluid pressure control device that controls a brake fluid pressure of the brake cylinder. The brake fluid pressure control device supplies fluid from the master cylinder to the brake cylinder. Or brake fluid pressure limiting means for limiting the brake fluid pressure of the brake cylinder by discharging the fluid of the brake cylinder, and the brake fluid pressure limiting means reduces the brake fluid pressure to the regenerative brake. Regenerative braking according to the regenerative braking force of the system In a brake system that performs a regenerative cooperative braking operation by being controlled to be smaller than a brake hydraulic pressure when not operating, a hydraulic circuit between the master cylinder and the brake cylinder includes: Absorbing means for introducing and storing the brake fluid is connected thereto, a fluid introducing means for controlling the introduction of the brake fluid to the absorbing means, and a fluid return for returning the brake fluid of the absorbing means to the hydraulic circuit. A brake fluid pressure limiting means provided independently of the brake fluid pressure limiting means. 2. The brake system according to claim 1, wherein said liquid introducing means includes an on-off valve for opening and closing said hydraulic circuit and said absorbing means. 3. The brake system according to claim 1, wherein said liquid introduction means includes a liquid introduction pump for introducing brake fluid of said hydraulic circuit into said absorption means. 4. The absorbing means includes: an absorbing chamber into which the brake fluid of the hydraulic circuit is introduced; a back pressure chamber connected to the low pressure chamber; an absorbing piston for dividing the absorbing chamber and the back pressure chamber; Wherein the liquid introduction means includes an on-off valve for controlling the opening and closing of the back pressure chamber and the low pressure chamber, and the liquid return means supplies the brake fluid in the low pressure chamber to the back pressure chamber. The brake system according to claim 1, further comprising a pump for use in a vehicle. 5. The liquid introducing means includes a hydraulic pressure switching control valve for controlling connection / disconnection between the absorbing means and the hydraulic circuit, and an increase in the amount of brake fluid introduced into the absorbing means. The hydraulic pressure switching control valve is provided with an urging means for increasing the urging force according to the operation force of the master cylinder pressure,
The acting force of the brake cylinder pressure and the urging force of the urging means act, and the acting force of the master cylinder pressure is the difference between the acting force of the brake cylinder pressure and the urging force of the urging means. When the resultant force is larger than the resultant force, the hydraulic circuit and the absorbing means are connected continuously, and when the acting force of the master cylinder pressure is smaller than the resultant force of the acting force of the brake cylinder pressure and the urging force of the urging means, the hydraulic pressure is reduced. The brake system according to claim 1, wherein a circuit and the absorbing means are shut off. 6. The brake system according to claim 2, wherein said fluid return means includes a return pump for returning the brake fluid of said absorption means to said hydraulic circuit. 7. A return pump for returning the brake fluid of the absorbing means to the hydraulic circuit, and a second control for connecting / disconnecting the absorbing means and the suction side of the return pump. A hydraulic pressure switching control valve, and a second urging means for increasing an urging force in accordance with an increase in the amount of brake fluid introduced into the absorbing means; Is such that the acting force of the master cylinder pressure, the acting force of the brake cylinder pressure, and the urging force of the second urging means act, and the acting force of the master cylinder pressure is When the acting force and the urging force of the second urging means are larger than the resultant force, the suction side of the return pump and the absorbing means are shut off, and the acting force of the master cylinder pressure is applied to the brake cylinder pressure. Brake system according to claim 5, wherein the communicating with said absorbing means and the suction side of the pump for returning said when less than the resultant force of the biasing force of the the force second biasing means. 8. The brake system according to claim 6, further comprising an on-off valve for opening and closing between the suction side of the return pump and the absorbing means. 9. The brake fluid pressure limiting means for increasing the brake fluid pressure of the brake cylinder by connecting the master cylinder side and the brake cylinder side to supply brake fluid to the brake cylinder. A pressure valve,
A pressure reducing valve for discharging the brake fluid of the brake cylinder, which is disconnected from the master cylinder side by a pressure increasing valve when the brake fluid pressure of the brake cylinder is reduced, to a low pressure chamber, and the brake fluid discharged to the low pressure chamber. 9. The brake system according to claim 1, further comprising: a pump that recirculates the hydraulic pressure circuit on the master cylinder side of the pressure increasing valve. 10. The brake fluid pressure control device is at least one of an antilock brake control device, a traction control device, a vehicle stability control device, a brake assist device, and an automatic brake device. The described brake system. 11. The brake fluid pressure control device is at least one of an anti-lock brake control device, a traction control device, a vehicle stability control device, a brake assist device, and an automatic brake device. The brake system according to claim 9, wherein the brake system is a pump of a hydraulic pressure control device. 12. The pump of the brake fluid pressure control device,
The brake fluid of the brake fluid pressure control reservoir of the brake fluid pressure control device is circulated to the hydraulic circuit, and when the brake fluid of the brake fluid pressure control reservoir runs out, the brake fluid of the absorbing means is discharged to the hydraulic pressure circuit. 12. The brake system according to claim 11, wherein the brake system is adapted to recirculate in the circuit. 13. When the brake fluid is stored in the brake control reservoir, the pump and the absorbing means of the brake fluid pressure control device are shut off, and the brake fluid is stored in the brake control reservoir. 13. The brake system according to claim 12, further comprising a reservoir priority valve for connecting the pump of the brake fluid pressure control device and the absorbing means when there is no pump. 14. When the master cylinder communicates with a pump suction side of the brake fluid pressure control device,
The brake system according to claim 11, further comprising an absorption prohibiting unit that prohibits the brake fluid of the master cylinder from flowing into the absorption unit from the pump suction side. 15. The brake fluid pressure control device is controlled by a brake operating force of the brake operating member, and is provided with a pressure sensor for detecting the master cylinder pressure. 2. The method according to claim 1, wherein the determined master cylinder pressure is used as a brake operating force of the brake operating member.
5. The brake system according to any one of items 4. 16. The liquid introduction means and the liquid return means are controlled based on a brake fluid pressure detected by a second pressure sensor and the master cylinder pressure detected by the pressure sensor. The brake system according to claim 15. 17. The brake fluid pressure of the brake cylinder is estimated based on the master cylinder pressure detected by the pressure sensor and the operation state of the brake fluid pressure control device. The brake system according to claim 15, wherein the liquid introduction unit and the liquid return unit are controlled based on the master cylinder pressure detected by the pressure sensor. 18. A brake fluid introduction amount detecting means for detecting an introduction amount of the brake fluid introduced into the absorption means, and based on the brake fluid introduction amount detected by the brake fluid introduction amount detection means. 18. The brake system according to claim 16, wherein the liquid introduction unit and the liquid return unit are controlled. 19. Stroke detecting means for detecting an operating stroke of the brake operating member is provided, and the liquid introducing means and the liquid returning means are controlled based on the operating stroke detected by the stroke detecting means. The brake system according to claim 15, wherein: