JPH06286587A - Brake device for vehicle - Google Patents

Abstract

PURPOSE:To provide a brake device for vehicle which can attain small size of the device and improve the general purpose adaptability. CONSTITUTION:This brake device is constituted of respective master cylinders 12 to respectively generate brake pressure for left side wheels and right side wheels, a braking force distribution control part which can discriminately distribute working force to the respective master cylinders 12 receiving oil supply from a brake force distribution control circuit 8, and a hydrobooster part which receives oil supply from an oil pump 95, amplifies the operating force from a brake pedal 66 side, and transmits it to the braking force distribution control part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle brake device capable of changing the braking force of left and right wheels.

[0002]

2. Description of the Related Art When a vehicle is turning, it is possible to improve the turning performance of the vehicle by generating a brake pressure for one of the left and right wheels and actively controlling the yaw moment. You can Conventionally,
The control of each brake pressure of the left and right wheels is performed by a brake device, and this brake device is provided between each master cylinder and the operation rod connected to the brake pedal side.
Brake force distribution control circuit (brake force distribution control means) that makes it possible to distribute the operating force to each master cylinder with a difference
Is equipped with.

The operating force from the brake pedal side is amplified by a vacuum type brake booster and transmitted to the braking force distribution control circuit side. According to this brake device, when the driver operates the brake pedal, the operating force is amplified by the brake booster and transmitted to the braking force distribution control circuit. The braking force distribution control circuit distributes the amplified operating force to the respective master cylinders with a difference in the operating force, thereby changing the braking force between the left and right wheels. Also, even when the driver is not operating the brake pedal, the braking force distribution control circuit distributes the operating force to each master cylinder with a difference.
The braking force can be changed between the left and right wheels.

[0004]

However, since the above-described brake device has the braking force distribution circuit, the entire device is longer than the general brake device including the brake booster and the master cylinder. was there. Therefore, it is conceivable to shorten the stroke of each master cylinder or the like to shorten the entire apparatus. However, if the stroke is shortened, a large force is required to operate the master cylinder or the like. Therefore, it is conceivable to increase the amplification factor of the brake booster in order to obtain a large operating force, but in order to increase the amplification factor, the diameter of the diaphragm built in the brake booster must be increased. Therefore, the brake booster is increased in the radial direction, which is not preferable.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a brake device for a vehicle, which enables downsizing of the device and improvement in versatility.

[0006]

In order to achieve the above object, a vehicle brake device according to the present invention includes a master cylinder for generating a brake pressure for a left wheel and a master cylinder for generating a brake pressure for a right wheel, and a hydraulic fluid from a hydraulic fluid source. Of the brake force distribution control means for distributing the operating force to each master cylinder with a difference, and a brake booster for amplifying the operation force from the brake pedal side and transmitting it to the brake force distribution control means. In the vehicle brake device including the above, the brake booster is composed of a hydraulic brake booster that operates by receiving supply of a pressure fluid from the pressure fluid source.

Preferably, each of the master cylinders is a single master cylinder for generating a brake pressure for the left front wheel and a brake pressure for the right front wheel, and the brake pressure on the left and right rear wheels is generated by the operation control pressure of the hydraulic brake booster. Is configured to let.

[0008]

According to the vehicle brake device of the invention, the operating force from the brake pedal side is amplified by the hydraulic brake booster and transmitted to the braking force distribution control means. Further, the brake pressure for the left front wheel and the brake pressure for the right front wheel are generated by the single master cylinders, respectively, and the brake pressure on the left and right rear wheels can be generated by the operation control pressure of the hydraulic brake booster.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to FIGS. A system configuration diagram of the brake device of the present invention is shown in FIG. The brake device 2 includes a brake unit 4, a brake pressure circuit 6, a brake force distribution control circuit 8, a controller 10, and the like.

As shown in FIG. 2, the brake unit 4 comprises a master cylinder section, a braking force distribution control section, a balance mechanism section and a hydro booster section, each of which has a housing. These constituent members are arranged so as to extend in the front end direction in the order of the balance mechanism unit, the braking force distribution control unit, and the master cylinder unit with the hydrobooster unit being the proximal end side, and are connected to each other.

The master cylinder section is composed of a pair of master cylinders 12. One master cylinder 12
Generates a brake pressure on the right wheel side, and the other master cylinder 12 generates a brake pressure on the left wheel side. Each master cylinder 12 is of a so-called tandem type and includes a primary piston 14 and a secondary piston 15. A primary piston (hereinafter, referred to as P piston) 14 is arranged on the base end side in the master cylinder 12, and a secondary piston (hereinafter, referred to as S piston) 15 is a tip from the P piston 14 in the master cylinder 12. It is located at the approximate center of the side space.

A space between the P piston 14 and the S piston 15 serves as a first brake pressure chamber 16, and the S piston 15
The space on the leading end side is defined as the second brake pressure chamber 17. A return spring 18 is housed in each of the brake pressure chambers 16 and 17, and each return spring 1
8 returns each piston 14, 15 to the initial position when the braking device 2 is not actuated.

As shown in FIG. 2, each piston 14, 15
Of each master cylinder 12 when the
Are provided with a first port 19 and a second port 20 facing the first brake pressure chamber 16, and a third port 21 and a fourth port 22 are provided in the second brake pressure chamber 1.
7 are provided respectively. The brake pressure on the rear wheel side is generated in the first brake pressure chamber 16, and the brake pressure on the front wheel side is generated in the second brake pressure chamber 17. The tip of the P piston 14 and the S piston 15
Valve lips are provided at both ends of the.

The braking force distribution control section is composed of a pair of control cylinders 25 and 26.
Among the five and 26, the one relating to the right wheel side master cylinder 12 is the first control cylinder 25 and the left wheel side master cylinder 1
The second control cylinder 26 relates to the second control cylinder 26. Control pistons 27 and 28 are slidably fitted in the control cylinders 25 and 26, respectively. Each control piston 27,
28, piston rods 29, 30 are formed, and these piston rods 29, 30 extend from both end faces of each control piston 27, 28 in the distal and proximal directions. Of the piston rods 27 and 28, the one on the first control piston 25 side is the first piston rod 29, and the one on the second control piston 26 side is the second piston rod 30.
And

The tip side of each piston rod 29, 30 is
Extend to the master cylinder section side, and
It is integrated with the piston 14. On the other hand, the base ends of the piston rods 29 and 30 project into the balance mechanism portion, and the projecting base end surface is provided with a receiving hole 31. The bottoms of the receiving holes 31 are formed in a cone shape, and the action rods 53 of the balance mechanism are inserted into the receiving holes 31.

The inside of the first control cylinder 25 is divided into a base end side and a tip end side by a first control piston 27, and a space on the base end side serves as a first control pressure chamber 32 and a space on the tip end side is defined. It is the second control pressure chamber 33. On the other hand, the inside of the second control cylinder 26 is divided into a base end side and a tip end side by a second control piston 28, and a space on the base end side serves as a third control pressure chamber 34 and a space on the tip end side is formed. Fourth control pressure chamber 35
It is said that.

A first control port 36 and a first connection port 38 are provided on the base end side of the first control pressure chamber 32, and a second control port 37 and a second connection are provided on the tip end side of the second control pressure chamber 33. Ports 39 are provided respectively. On the other hand, a third connection port 40 is provided on the base end side of the third control pressure chamber 34, and a fourth connection port 41 is provided on the tip end side of the fourth control pressure chamber 35.

As shown in FIG. 1, the first connection port 38 and the fourth connection port 41 are connected via the first oil passage 42, and the second connection port 39 and the third connection port 40 are connected to each other. , Are connected via the second oil passage 43. A right wheel side oil passage 100 and a left wheel side oil passage 101 from the brake pressure distribution control circuit 8 side are connected to the first and second control ports 36 and 37, respectively, so that pressurized oil can be supplied. Has become. Therefore, the oil introduced from the first control port 36 enters the first control pressure chamber 32, and the oil
It flows into the fourth control pressure chamber 35 through the oil passage 42. In addition, the oil introduced from the second control port 37 is
It enters the control pressure chamber 33 and flows into the third control pressure chamber 34 through the second oil passage 43. Note that, in FIG. 2, the illustration of the first oil passage 42 and the second oil passage 43 is omitted.

First control pressure chamber 32 and second control pressure chamber 33
Between the third control pressure chamber 34 and the fourth control pressure chamber 35 is oil-tightly sealed by an oil seal provided around the first control piston 27. It is oil-tightly sealed by an oil seal. When the brake device 2 is not operated, the control pistons 27, 28 are pushed by the return spring 18 in the master cylinder 12 and are positioned near the base end sides of the control cylinders 25, 26. At this time, the first and third
The volumes of the control pressure chambers 32 and 34 are minimum.

A balance mechanism 50 is housed in the housing of the balance mechanism section. The balance mechanism 50
It is composed of a support rod 51, a balance bar 52, and a pair of action rods 53. The tip end portion of the support rod 51 is inserted into a guide hole 54 provided in the housing between the first control cylinder 25 and the second control cylinder 26, and the base end portion extends into the hydrobooster portion.
Both ends of the support rod 51 are slidably supported via bearings (not shown).

The balance bar 52 is rotatably connected to the support rod 51 at its center position, and the support rod 51 is in a state in which the brake device is not operating.
It extends so as to be orthogonal to. Both ends of the balance bar 52 are arranged equidistant from the support rod 51,
The base ends of the working rods 53 are rotatably connected to both ends of the balance bar 52. The tips of the working rods 53 are provided with the receiving holes 3 of the piston rods 29 and 30.
1 is inserted in each.

The hydro-booster section has a power piston 6
0, spool valve mechanism 61, ratio lever 62, etc., and these components are housed in a housing. The power piston 60 has a sliding hole formed in the housing and opened at both ends, that is, a power cylinder 63.
Is slidably fitted to. This power piston 60
The front end side of the power piston 60 is integrated with the base end of the support rod 51 of the balance mechanism 50, and the base end side of the power piston 60 projects to the outside of the housing. A hole 64 extending toward the tip side is formed in the base end surface of the power piston 60 protruding to the outside of the housing, and a control rod 65 is slidably inserted in the hole 64. In the hole 64, the base end of the control rod 65 is connected to the tip of an operation rod 67 connected to the brake pedal 66. A spring seat 68 fitted to the operating rod 67
A return spring 69 is provided between the return spring 69 and the base end side of the housing.
Returns the operation rod 67 to the original position when the brake pedal 66 is not operated. In addition, the brake pedal 6
As shown in FIG. 1, 6 has a fulcrum on the base end side pivotally supported by a bracket provided on the housing.

A booster chamber 70 is formed in the housing of the hydrobooster section. Power cylinder 6
3 and the inside of the booster chamber 70 are in communication with each other, and
A pressure receiving surface 71 is formed on the inner power piston 60. The power piston 60 receives pressure on the pressure receiving surface 71 and is moved toward the tip end side in the axial direction. The spool valve mechanism 61 includes a spool 74 that moves in the axial direction, and the housing of the hydrobooster section is provided with an inlet 72 for receiving oil supply and an outlet 73 for discharging oil.

The spool 74 is provided with a plurality of oil holes. When the spool 74 is pushed and moved toward the tip end side in the axial direction, the introduction port 72 and the booster chamber 70 are formed due to the positional relationship with the oil holes. Oil is supplied from the inlet 72 into the booster chamber 70. As a result, the pressure in the booster chamber 70 becomes high. On the other hand, when the spool 74 is pushed back toward the base end side in the axial direction and moved, the discharge port 73 and the booster chamber 70 are connected due to the positional relationship of the oil holes, and oil is discharged from the booster chamber 70 to the discharge port 73. Is discharged. As a result, the pressure in the boosting chamber 70 becomes low. Further, at the intermediate position of the spool 74, the introduction port 72 and the discharge port 73 are closed due to the positional relationship with the oil hole, and the pressure in the booster chamber 70 is maintained constant.

The spool 74 is normally pushed by a spring to be located on the base end side, and is pushed by one end of the ratio lever 62 to move in the axial direction. A notch 75 is provided on the peripheral surface of the power piston 60 exposed in the booster chamber 70. Further, the control rod 65 in the power piston 60 is also provided with a hole 76 at the position of the cutout 75 of the power piston 60.

The ratio lever 62 is composed of a first lever 77 and a pair of second levers 78. First lever 7
7 is sandwiched between the respective second levers 78 and is connected to the respective second levers 78 at a substantially central position. One end side of the first lever 77 is pivotally supported by a pin 79 fixed to the housing in the vicinity of the base end side of the spool 74, and the other end is inserted into the hole 76 of the control rod 65. Second lever 7
One end of 8 is located at one end side of the first lever 77, is loosely fitted to the pin 79 at both ends thereof, and the other end is inserted into the notch 75 of the power piston 63. It is rotatable about 63. In addition,
The other end of the power piston 63 is not in contact with the control rod 65.

When the brake pedal 66 is depressed and the control rod 65 is moved to the tip end side in the axial direction, the first lever 77 rotates clockwise around the one end pivotally supported by the pin 79 as seen in FIG. Is rotated to. When the first lever 77 is rotated clockwise, a force acts on the connecting portion of the second lever 78 with the first lever 77, and the second lever 78 is rotated counterclockwise with respect to the power piston 63, and the second lever 78 is rotated. One end of the lever 78 pushes out the base end of the spool 74. The base end is pushed and the spool 74
When is moved to the tip side, oil is supplied from the inlet 72 to the booster chamber 70, the pressure in the booster chamber 70 is applied to the pressure receiving surface 71 of the power piston 60, and the power piston 60 moves forward.

When the depression of the brake pedal 66 is maintained constant, the power piston 60 precedes the control rod 65 toward the tip side, so that the second lever 78 is returned to the original position with respect to the first lever 77. Be done. At this time, the spool 74 is in the neutral position, and the inlet 72 and the outlet 73
Are blocked, and the pressure in the booster chamber 70 is maintained. Therefore, the power piston 60 stops at that position.

When the depression of the brake pedal 66 is released, the control rod 65 moves to the base end side. At this time,
Since the power piston 60 moves a little later than the movement of the control rod 65, the first lever 77 is rotated counterclockwise about the one end side pivotally supported by the pin 79. When the first lever 77 is rotated counterclockwise, the first lever 77
A force acts on the connecting portion between the second lever 78 and the power piston 63, and the second lever 78 is rotated clockwise with respect to the power piston 63.
One end side of 8 enables the spool 74 to return to the base end side. When the spool 74 is moved to the base end side, the booster chamber 7
The oil in 0 is discharged from the discharge port 73, the pressure in the booster chamber 70 decreases, and the power piston 60 moves back.

The amount of oil supplied to the booster chamber 70 or the amount of oil discharged from the booster chamber 79 is determined according to the amount of depression of the brake pedal 66. The power piston 60 is moved accordingly. Referring back to FIG. 1, the brake pressure circuit 6 includes a reservoir tank for storing brake oil,
Disc brake mechanism 90 arranged on each wheel FR (right front wheel), RR (right rear wheel), FL (left front wheel), RL (left rear wheel), and each brake pressure chamber 16, 17 to each disc brake mechanism. Each of the brake hoses 91 is capable of supplying a brake pressure to 90, each of the brake pressure chambers 16 and 17, and an oil passage 93 that connects the inside of a reservoir tank 92 attached to the housing.

Each brake hose 91 has a first port 19
And the third port 21. Also, oil passage 9
3 is connected to the second port 20 and the fourth port 22. A PCV (proportioning valve) 94 is inserted in the middle of the brake hose 91 on the rear wheel side. The braking force distribution control circuit 8 includes a reservoir tank 92, an oil pump 95, and a pressure control valve 104.
And a pair of electromagnetic switching valves 110 and 114, etc., which are connected by oil passages 97 to 103, respectively. The oil pump 95 is rotationally driven by, for example, an electric motor (not shown), and the reservoir tank 92 is provided.
The brake oil sucked in from is pumped to the pressure control valve 104 via the oil passage 97 and to the inlet 72 of the spool valve mechanism 61 in the hydrobooster section via the oil passage 102. The discharge port 73 of the spool valve mechanism 61 is connected to the oil passage 103.
It is connected to the reservoir tank 92 via. In addition,
An accumulator 108 is connected in the middle of the oil passage 97.

The pressure control valve 104 is a 4-port 2-position electromagnetic throttle switching valve. At the first switching position 105 shown in FIG. 1, the pressure control valve 104 connects the oil passage 98 extending from the reservoir tank 92 to the electromagnetic switching valves 110, 114 side and closes the oil passage 97 extending from the oil pump 95. Further, in the second switching position 106, the oil pump 95
Is connected to the electromagnetic switching valves 110 and 114, and the oil passage 98 extending from the reservoir tank 92 is closed. The pressure control valve 104 includes electromagnetic switching valves 110 and 11
While receiving servo pressure from the oil passage 96 extending to the 4 side,
The solenoid 107 is continuously switched between the first and second switching positions according to the amount of electricity supplied to the solenoid 107. Therefore,
The pressure control valve 104 moves from the oil passage 97 to the reservoir tank 92.
The amount of oil that flows into the oil passage 98 that extends toward the solenoid valve is increased, and the amount of oil that flows into the oil passage 96 that extends toward the electromagnetic switching valves 110 and 114 is decreased. On the contrary, the amount of oil flowing from the oil passage 97 into the oil passage 98 extending to the reservoir tank 92 is decreased, and the amount of oil flowing into the oil passage 96 extending toward the electromagnetic switching valves 110 and 114 is increased.

Such control of the pressure control valve 104 is performed in proportion to the amount of electricity supplied to the solenoid 107. The energization amount to the solenoid 107 is controlled by the controller 10 according to the depression amount of the brake pedal 66. The pressure control valve 104 is not limited to the one described above, and may be a valve mechanism that can continuously and variably supply brake oil to the electromagnetic switching valves 110 and 114, for example, a spool valve.

The electromagnetic switching valves 110 and 114 are two-position switching valves. Of these electromagnetic switching valves 110 and 114, the one that controls the brake pressure on the right wheel side is the first electromagnetic switching valve 11
The second electromagnetic switching valve 114 controls the left side brake pressure. The first electromagnetic switching valve 110 and the second electromagnetic switching valve 114 are the same. In the first switching position 111 shown in FIG. 1, the first electromagnetic switching valve 110 connects the oil passage 99 extending to the reserve tank 92 and the right wheel side oil passage 100, and extends from the pressure control valve 104.
Shut off 6. From this state, when the solenoid 113 of the first electromagnetic switching valve 110 is excited, the first electromagnetic switching valve 11
0 is switched to the second switching position 112. At the second switching position 112, the oil passage 96 extending from the pressure control valve 104 and the right wheel side oil passage 100 are connected, and the oil passage 99 extending to the reserve tank 92 is shut off.

The second electromagnetic switching valve 114 is the first electromagnetic switching valve 114 shown in FIG.
At the switching position 115, the oil passage 99 extending to the reserve tank 92 and the left wheel side oil passage 101 are connected, and the pressure control valve 1
The oil passage 96 extending from 04 is shut off. From this state, when the solenoid 117 of the second electromagnetic switching valve 114 is excited, the second electromagnetic switching valve 114 is switched to the second switching position 116. In the second switching position 116, the pressure control valve 10
The oil passage 96 extending from 4 is connected to the left wheel side oil passage 101, and the oil passage 99 extending to the reserve tank 92 is shut off.

The right wheel side oil passage 100 is connected to the first control port 36 provided in the braking force distribution control section of the brake unit 4, and the left wheel side oil passage 101 is connected to the second control port 37.
Respectively connected to. The right wheel side oil passage 100 is the first
Brake oil can be supplied to the first control pressure chamber 32 via the control port 36, and the left wheel side oil passage 101 can supply brake oil to the second control pressure chamber 33 via the second control port 37. It should be noted that the first electromagnetic switching valve 110 and the second switching position 112 do not become the second switching positions 112 and 116 at the same time.

The controller 10 incorporates a central processing unit (CPU), a storage device such as a ROM and a RAM, an input / output device, etc., which are not shown. On the input side of the input / output device, various sensors such as a handle (not shown)
A steering wheel steering angle sensor that detects the steering angle of the vehicle, a vehicle speed sensor that detects the vehicle speed, a lateral G sensor that detects the acceleration in the vehicle width direction, a brake switch that detects the depression operation of the brake pedal 66, etc. are electrically connected. .

On the output side of the input / output device of the controller 10, an electric motor (not shown) of the oil pump 95, the solenoid 107 of the pressure control valve 104 and the solenoids 113 and 117 of the electromagnetic switching valves 110 and 114 are provided.
Etc. are electrically connected. Therefore, the controller 10 can operate the electric motor to control the discharge amount of the brake oil from the oil pump 95. Further, by exciting the solenoid 107 of the pressure control valve 104,
The amount of brake oil supplied to each electromagnetic switching valve 110, 114 can be controlled. Further, the first electromagnetic switching valve 1
The first and second switching positions 111 and 112 of 10 can be switched and the first and second switching positions 115 and 116 of the second electromagnetic switching valve 114 can be switched and controlled.

First, the normal brake control will be described. When the driver depresses the brake pedal 66,
The hydro booster unit applies a force corresponding to the amount of depression of the brake pedal 66 to the power piston 60, and the power piston 60 is moved. The movement of the power piston 60 is
That is, the support rod 51 integrated with the power piston 60 moves, and the balance bar 52 moves together with the support rod 51. The action rods 53 are rotatably balanced at both ends of the balance bar 52, and the action rods 53 are arranged at equal distances from the support rod 51. Moves without rocking. Therefore, each working rod 53 moves to the same position as each other and pushes out each control piston 27, 28 by the same distance. As a result, each P
The pistons 14 and the like move forward to the same position to generate the same brake pressure on the right wheel side and the left wheel side.

The moving distance of the balance bar 52 changes according to the amount of depression of the brake pedal 66. Therefore, the magnitude of the brake pressure generated in each of the brake pressure chambers 16 and 17 is proportional to the depression amount of the brake pedal 66. Next, the automatic brake control will be described. The controller 10 performs the automatic brake control when the brake pedal 66 is not operated during turning of the vehicle, for example.

For example, when the controller 10 operates only the disc brake mechanism 90 on the right wheel side,
The electromagnetic switching valve 110 is switched to the second switching position 112, and the solenoid 107 of the pressure control valve 104 is supplied with an electric current of an amount corresponding to the required braking force. Therefore,
An amount of oil corresponding to the amount of electricity supplied to the solenoid 107 is supplied to the right wheel side oil passage 100 and flows into the first control pressure chamber 32 via the first control port 36.

The oil flowing into the first control pressure chamber 32 causes the first control piston 27 to move forward and
The oil in the second control pressure chamber 33 is discharged to the left wheel side oil passage 101. At this time, the working rod 5 of the balance bar 52
Since 3 is separated from the receiving hole 54 on the base end side of the first control piston 27, the forward movement of the first control piston 27 does not affect the second control piston 28 and the second control piston 28
Keeps stopped. Therefore, the support rod 51 does not move.

When the first control piston 27 moves forward, the P piston 14 on the right wheel side is pushed out and the brake pressure on the right wheel side is generated. On the other hand, since the second control piston 28 is stopped, it does not affect the brake pressure on the left wheel side.
The controller 10 is the solenoid 1 of the pressure control valve 104.
It is possible to change the magnitude of the generated brake pressure by adjusting the energization amount of 07 and operating the movement amount of each control piston 27, 28.

The disc brake mechanism 90 on the left wheel side
When operating only the second electromagnetic switching valve 114 to the second switching position 116, oil is supplied from the second control port 37 to the second control pressure chamber 33 via the left wheel side oil passage 101, and Oil may be supplied from the second control pressure chamber 33 into the third control pressure chamber 34 via the oil passage 43.

Next, the braking force distribution control will be described. In the braking force distribution control, there are cases where automatic braking is performed during execution of normal braking and cases where normal braking is performed during execution of automatic braking. First, a case will be described in which the controller 10 performs automatic braking on the right wheel side, for example, when the driver is operating the brake pedal 66.

In this case, the first control piston 27 moves further from the position corresponding to the depression amount of the brake pedal 66, while the second control piston 28 moves the brake pedal 6
Move back from the position corresponding to the stepping amount of 6. Therefore, the forward travel distance of the P piston 14 on the right wheel side increases and the brake pressure on the right wheel side increases, and the forward travel distance of the P piston 14 on the left wheel side decreases and the brake pressure on the left wheel side decreases. . Since the control pistons 27 and 28 are balanced by the balance bar 53, the change amount of the left wheel side brake pressure is equal to the change amount of the right wheel side brake pressure.

Next, a case where the driver operates the brake pedal 66 while the controller 10 is performing the automatic braking on the right wheel side will be described. in this case,
The support rod 51 and the balance bar 52 are pushed and moved by the control rod 65. The balance bar 52 is balanced with the support rod 51 at its central position, and
Since the working rods 53 are arranged equidistant from each other with respect to the support rod 51, when the working rods 53 are inserted into the receiving holes 31 on the base end side of the control pistons 27 and 28 and are brought into contact therewith. , The balance bar 52 has a support rod 5
Swung with respect to 1. And the balance bar 52 is
Each working rod 5 moves while maintaining this swing angle.
Move 3 equidistant from each other. Therefore, the control pistons 27 and 28 move forward from the position where the automatic brake control is performed, and the left and right brake pressures increase by a magnitude corresponding to the forward movement distance.

In the vehicle brake system of the first embodiment, the hydraulic hydro booster unit amplifies and transmits the operating force from the brake pedal side to the braking force distribution control unit side. The hydraulic hydro booster section is smaller and has a higher amplification factor than the vacuum brake booster.
Therefore, it is possible to shorten the total length of each cylinder in the master cylinder section and the braking force distribution control section, and there is an effect that the brake unit can be downsized.

The second embodiment of the present invention will be described in detail below with reference to FIGS. 3 and 4. In the second embodiment, the same members as those in the first embodiment are designated by the same reference numerals. FIG. 3 shows a system configuration diagram of the brake device 2 of the present invention. The brake device 2 of the second embodiment comprises a brake unit 4, a brake pressure circuit 6, a brake force distribution control circuit 8 and a controller 10. The braking force distribution control unit and the balance mechanism unit of the brake unit 4, the braking force distribution control circuit 8,
The controller 10 is configured similarly to the first embodiment. Therefore, these explanations are omitted.

In the brake unit 4, each master cylinder 12 of the master cylinder section is of a so-called single type. Therefore, each master cylinder 12
Has only a primary piston 14 (hereinafter referred to as a P piston). The space formed by the P piston 14 in each master cylinder 12 is the first brake pressure chamber 16. A return spring 18 is housed in each brake pressure chamber 16, and each return spring 18 returns the P piston 14 to the initial position when the brake device 2 is not operated.

As shown in FIG. 4, each master cylinder 12 is provided with a first port 19 and a second port 20 facing the first brake pressure chamber 16 when the P piston 14 is not moving. There is. In these first brake pressure chambers 16, brake pressure on the front wheel side is generated. Therefore, the brake pressure on the right front wheel side is generated in the first brake pressure chamber 16 of the one master cylinder 12,
The brake pressure on the left front wheel side is generated as the first brake pressure 16 of the other master cylinder 12.

On the other hand, as shown in FIG. 4, a brake port 130 is provided in the housing of the hydrobooster section so as to face the booster chamber 70. This brake port 13
From 0, the brake pressure on the rear wheel side is generated. In the brake pressure circuit 6, the right front wheel FR is connected to the first port 19 of each master cylinder 12 via the brake hose 91.
And the left front wheel FL is connected to the disc brake mechanism 90, and ABSs are provided in the middle of each brake hose 91.
The unit 123 is inserted. A PCV (proportioning valve) 9 is connected to the brake port 130 of the hydro booth booster via a brake hose 122.
4 are connected to the PCV 94, and brake hoses extending to the disc brake mechanism 90 on the rear wheel side are connected to the PCV 94. An ABS unit is inserted in the brake hose 122 between the brake port 130 and the PCV 94.

The ABS (anti-lock braking system) unit 123 is of a three-channel type, and its braking system is divided into three blocks of a left front wheel side FL, a right front wheel side FR and left and right rear wheel sides RL, RR. It is divided. The ABS unit 123 controls the brake pressure for each block to prevent wheel lock and to achieve stability during braking. . In addition, this ABS unit 1
23, an oil passage 120 extending from the oil pump 95,
The oil passage 12 extending to the reservoir tank 92 is connected.

In the brake device of the second embodiment, the master cylinder 12 is of a single type, and the control pressure of the booster chamber of the hydro booster section is used as the brake pressure on the left and right rear wheels. Therefore, the total length of the brake unit 4 can be further shortened, and the brake device can be downsized.
Further, since the left and right brake force distribution control is performed only on the front wheel side and the rear wheel side brake control is performed simultaneously on the left and right wheels, a brake hose extending from each master cylinder 12 and hydro booster portion to the disc brake mechanism 90 of each wheel. The ABS unit 123 of 3 channels can be attached in the middle of 91, 122. Also, on the rear wheel side,
Since the left and right brake force distribution control is not performed, it is possible to equip a vehicle equipped with this brake device with a rear wheel LSD (limited slip differential). further,
It has an excellent effect that only one PCV (proportioning valve) is required on the rear wheel side.

[0055]

As described above, the vehicle brake device of the present invention receives the supply of the pressure liquid from the master cylinders that respectively generate the brake pressures for the left and right wheels and the pressure liquid source. A vehicle provided with a brake force distribution control means for distributing the operating force to each master cylinder with a difference, and a brake booster for amplifying an operation force from the brake pedal side and transmitting the amplified operation force to the brake force distribution control means In the above braking device, the brake booster is composed of a hydraulic brake booster that operates by receiving the supply of the pressure fluid from the pressure fluid source. Therefore, since the amplification of the operating force can be sufficiently ensured, the total length of each master cylinder and the like can be shortened, and the brake device can be downsized.
Further, if each of the master cylinders is a single master cylinder that generates a brake pressure for the left front wheel and a brake pressure for the right front wheel, and the brake pressures on the left and right rear wheels are generated by the operation control pressure of the hydraulic brake booster. , The brake device can be made smaller, and this brake device has a 3-channel ABS device and a rear wheel L.
Equipment such as SD (Limited Slip Diff) can also be incorporated, resulting in excellent effects such as improvement in versatility of the braking device.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a brake device to which the present invention is applied.

2 is a cross-sectional view of the brake unit of FIG.

FIG. 3 is a schematic configuration diagram showing a second embodiment of a brake device to which the present invention has been applied.

4 is a cross-sectional view of the brake unit of FIG.

[Explanation of symbols]

 2 Brake device 4 Brake unit 6 Brake pressure circuit 8 Brake force distribution control circuit 10 Controller 12 Master cylinder 14 Primary piston (P piston) 15 Secondary piston (S piston) 27 First control piston 28 Second control piston 32 First control pressure Chamber 33 Second control pressure chamber 34 Third control pressure chamber 35 Fourth control pressure chamber 42 First oil passage 43 Second oil passage 50 Balance mechanism 51 Support rod 52 Balance bar 60 Power piston 61 Spool valve mechanism 62 Ratio lever 65 Control Rod 66 Brake pedal 67 Operation rod 70 Booster chamber 92 Reservoir tank 95 Oil pump 104 Pressure control valve 110 First electromagnetic switching valve 114 Second electromagnetic switching valve 130 Brake port

Claims (2)

[Claims] 1. A master cylinder that generates brake pressure for the left wheel and a master cylinder that generates brake pressure for the right wheel, respectively, and supply of pressure fluid from a pressure fluid source to distribute the operating force to each master cylinder with a difference. A braking force distribution control means, and a brake booster that amplifies the operating force from the brake pedal side and transmits the braking force to the braking force distribution control means, wherein the brake booster is pressurized from the pressure fluid source. A brake device for a vehicle, wherein the brake device is a hydraulic brake booster that operates by receiving supply of liquid. 2. Each of the master cylinders is a single master cylinder that generates a brake pressure for the left front wheel and a right front wheel, and the brake pressure for the left and right rear wheels is generated by the operation control pressure of the hydraulic brake booster. The brake device for a vehicle according to claim 1, wherein: