JP2706931B2 - Vehicle braking system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art At the time of turning a vehicle, if the yaw moment generated in the vehicle is positively controlled by operating each braking force of the left and right wheels, the turning performance of the vehicle can be improved. Conventionally, as a brake device capable of performing the left and right wheel brake force difference control, a controller uses a brake oil pressure generated by a driver operating a brake pedal as a left wheel and a right wheel brake pressure. A type in which the yaw moment is positively generated by changing the braking force between the left and right wheels by distributing at an appropriate ratio, or when the driver does not operate the brake pedal, There is known a type in which a brake pressure is generated on one of the left and right wheels, thereby positively generating a yaw moment.

[0003]

However, in the above-mentioned conventional brake system for a vehicle, there is a limitation in performing the braking force difference control between the left and right wheels. In other words, in the former type of brake device, when the driver does not operate the brake pedal, the braking force difference control of the left and right wheels cannot be performed, and in the latter type of brake device, However, when the driver operates the brake pedal, there is a problem that the braking force difference control between the left and right wheels cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has been made in view of the above circumstances. It is intended to provide a device.

[0005]

According to the present invention, there is provided a brake pressure piston for generating a brake pressure for a left wheel and a brake pressure for a right wheel, and an operating rod for operating the brake pressure piston. Connecting means for transmitting the operating force from the brake pedal side to each operating rod, respectively, and braking force difference control means for increasing / decreasing the moving distance of each operating rod, wherein the connecting means is provided from the brake pedal side. A transmitting member for transmitting the operating force of the first and second members, and a rocking member whose center position is connected to the transmitting member and both ends are rotatably connected to the respective operating rods. A control piston provided, and a first fluid pressure circuit capable of supplying fluid pressure to pressure chambers formed on one side of one control piston and the other side of the other control piston; One of the other side and the other of the fluid pressure in the pressure chamber formed on one side of the control piston of the control piston and a second fluid pressure circuit that can be supplied and constitutes a brake device for a vehicle.

[0006]

When the driver operates the brake pedal, the oscillating member of the connecting means distributes this pedaling force evenly to the operation rods, so that the brake pressure pistons move by an equal distance to each other and are equal to the left and right. Braking force is generated.
On the other hand, when the brake pedal is not operated, when the fluid pressure is supplied through one of the first and second fluid pressure circuits, each control piston and each operation rod become the swing member. Are moved in opposite directions while oscillating, so that only one of the brake pressure pistons generates a braking force.

When the above operations are performed simultaneously, the operation rods moved by the brake pedal operation are further moved in opposite directions by the brake force difference control means. A large braking force is generated, while a small braking force is generated on the other.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of a brake device to which the present invention is applied. The brake device 1 includes a master cylinder unit 3, a brake pressure circuit 4, a brake pressure difference control circuit 5, a controller 7, and the like.

As shown in detail in FIG. 2, the master cylinder unit 3 includes a housing 10, a pair of brake pressure generating mechanisms 12, a pair of operating rods 14, 15, and a connecting mechanism 1.
7 and the like. The housing 10 includes a first component 21 and a second component 21 fixed to a distal end of the first component 21.
It comprises a component member 22, a pair of third component members 23 fixed to the distal end of the second component member 22, a pair of fourth component members 24 fixed to the distal end of each third component member 23, and the like.

The first component 21 has a large-diameter hole 21 in the center.
It is composed of a disk portion 21a in which c is perforated and a cylindrical portion 21b extending from the periphery of the disk portion 21a, and these are integrally formed. A sleeve 21d is integrally formed around the hole 21c of the disk portion 21a. The distal end of the push rod 26 is inserted into the sleeve 21d. The push rod 26 extends from a brake booster, that is, a so-called master back 27. When the brake pedal 28 (both shown in FIG. 1) is depressed, a push rod 26 described later is moved. The distal end surface 21e of the sleeve 21d functions as a stopper that restricts the swing angle of the balance bar 42 described later.

The second component member 22 is a cylindrical body having substantially the same diameter as the first component member 21, and has a guide hole 22a and a pair of large-diameter holes 22.
b, 22c, a pair of oil passages 22d, 22e and a pair of ports 22f, 22g. Guide hole 22a
Is formed at a center position of the base end face and extends to a position near the front end face. In addition, each large-diameter hole 22b, 22c
Are provided symmetrically with respect to the guide hole 22a. These large-diameter holes 22b and 22c extend in the axial direction of the master cylinder unit 3 and penetrate the second component member 22. A ring-shaped member 30 is disposed at the opening position of each of the large-diameter holes 22b and 22c.

Each third component member 23 has a small-diameter cylindrical portion 23a.
And a large-diameter cylindrical portion 23b, which are integrally formed. Each third component 23 is provided with a respective large-diameter hole 22.
b, 22c. The distal ends of these third components 23 are locked by a plate 32. Each fourth component 24 is a tubular member having a closed distal end, and a proximal end inserted into the large-diameter cylindrical portion 23 b of the third component 23. Holes 24a to 24d are formed at four locations in each fourth component 24. Each hole 24a ~
24d are provided at predetermined positions, respectively. In addition,
The space between each of the third constituent members 23 and the fourth constituent members 24 is oil-tightly sealed by an O-ring.

The operation rods 14 and 15 are inserted into the large-diameter holes 22b and 22c of the second component 22, and are movable in the axial direction. A first control piston 34 is formed at a central position of the first operation rod 14 inserted into the first large-diameter hole 22b. The second large-diameter hole 22c
A second control piston 35 is formed at a central position of the second operation rod 15 inserted into the inside. The spaces between the control pistons 34, 35 and the ring-shaped members 30 are first and second control pressure chambers 37, 38.

The first control pressure chamber 37 on the first large-diameter hole 22b side.
(Hereinafter referred to as the right wheel side first control pressure chamber 37R) and the second
The second control pressure chamber 38 on the large-diameter hole 22c side (hereinafter referred to as the right wheel-side second control pressure chamber 38R) is connected to the first oil passage 22d.
Are communicated through. Further, a second control pressure chamber 38 on the first large-diameter hole 22b side (hereinafter, the left wheel-side first control pressure chamber 38).
L) and the first control pressure chamber 3 on the second large-diameter hole 22c side.
7 (hereinafter referred to as left wheel side second control pressure chamber 37L)
It is communicated via the second oil passage 22e. further,
The right port first control pressure chamber 37R includes the first port 22.
f is open, and the second port 22g is open in the left wheel side first control pressure chamber 38L.

The space between the second component member 22 and each of the operating rods 14 and 15 and each of the ring members 30 is oil-tightly sealed with an O-ring. Each operating rod 1
Holes 14a and 15a are provided in the base end surfaces of the holes 4 and 15, respectively. The inner peripheral surface of each of the holes 14a and 15a is formed in a cone shape. Pressing portions 14b, 15b are integrally formed on the distal end surfaces of the operation rods 14, 15, respectively. Each of the pressing portions 14b and 15b extends in the axial direction from the center position of the distal end surface, and is inserted into a hole 47a of a primary piston 47 described later.

The connecting mechanism 17 includes a support rod 41, a balance bar 42, a pair of pressing rods 43, and the like.
These are accommodated in the first component 21. The base end of the support rod 41 is connected to the sleeve 21 of the first component 21.
d, and the tip is inserted into the guide hole 22a of the second component member 22. Both ends of the support rod 41 are slidably supported via bearings 45.

A hole 41a having a cone-shaped inner peripheral surface is provided in the base end surface of the support rod 41, and the tip of the push rod 26 is inserted into the hole 41a. Therefore, the support rod 41 is
6 to move in the axial direction. The balance bar 42 is rotatably connected to the support rod 41 at a center position thereof, and extends perpendicular to the support rod 41 when the brake device 1 is not operated (FIG. 1). Therefore, both ends of the balance bar 42 are arranged at positions equidistant from the support rod 41.
The base ends of the pressing rods 43 are rotatably connected to both ends of the balance bar 42, and the distal ends of the pressing rods 43 are inserted into the holes 14 a and 15 a of the operation rods 14 and 15. .

Each of the brake pressure generating mechanisms 12 is of a so-called tandem type, has a primary piston 47, a secondary piston 48, and the like, and is housed in each fourth component 24. Each of the brake pressure generating mechanisms 12 has the same configuration as each other. Therefore, the right wheel side brake pressure generating mechanism 12 will be described, and the description of the left wheel side brake pressure generating mechanism 12 will be omitted.

A primary piston (hereinafter, referred to as a P piston) 47 is accommodated in the base end of the fourth component member 24, protrudes from the base end, and extends into the small-diameter cylindrical portion 23a. A hole 47a is formed in the base end surface of the P piston 47. In addition, a secondary piston (hereinafter, S
The piston 48 is disposed at a substantially central position of the fourth component member 24. A hole 48a is formed in the base end surface of the S piston 48.

The space between the P piston 47 and the S piston 48 serves as a first brake pressure chamber 51.
The space on the tip side of the S piston 48 is a second brake pressure chamber 52. Return springs 54 and 55 are housed in the brake pressure chambers 51 and 52, respectively.
Spring seats 57, 58 holding the return springs 54, 55 guide pins 60, 61 extending from the pistons 47, 48, respectively. Therefore, each piston 4
When the volumes of the brake pressure chambers 51 and 52 change due to the reciprocating movement of the return springs 54 and 55, the return springs 54 and 55 can smoothly expand and contract. In this case, the hole 48a of the S piston 48 avoids the interference between the pin 60 and the S piston 48.

When the pistons 47 and 48 are not moving (the state shown in FIG. 1), the first and second holes 2
4a and 24b face the first brake pressure chamber 51, and the third and fourth holes 24c and 24d open to face the second brake pressure chamber 52, respectively. A rear wheel-side brake pressure is generated in the first brake pressure chamber 51, and a front wheel-side brake pressure is generated in the second brake pressure chamber 52.

The brake pressure circuit 4, as shown in FIG.
A reserve tank capable of storing brake oil, disc brake mechanisms 65 arranged on wheels FR (right front wheel), RR (right rear wheel), FL (left front wheel), RL (left rear wheel), and brake pressures Brake hoses 67 that can supply brake pressure from the chambers 51 and 52 to the disc brake mechanisms 65, and oil passages 69 that communicate between the brake pressure chambers 51 and 52 and the reservoir tank attached to the housing 10 and the like. It is configured. In addition, in FIG. 1, while illustration of this reservoir tank is omitted,
An oil passage 69 extends to a reservoir tank 63 related to an oil pump 71 described later.

Each brake hose 67 is connected to the second and fourth holes 24b and 24d. The oil passage 69 is
It is connected to the first and third holes 24a, 24c. Note that a proportioning valve 68 is interposed in the middle of the rear wheel side brake hose 67. The brake pressure difference control circuit 5 includes a reserve tank 63, an oil pump 7
1, an electromagnetic proportional pressure reducing valve 73, an electromagnetic switching valve 75, and the like, which are connected by oil passages 81 to 87. The oil pump 71 is driven to rotate by an electric motor 77 and pumps brake oil sucked from a reserve tank 63 to an electromagnetic proportional pressure reducing valve 73 via an oil passage 81. An accumulator 78 is connected in the middle of the oil passage 81.

The electromagnetic proportional pressure reducing valve 73 includes a solenoid 73
a, a spool 73b, a return spring 73c, and the like. The spool 73b is provided with an oil hole. When the solenoid 73a is excited, the spool 73b moves in the axial direction, and supplies the electromagnetic switching valve 75 with brake oil pressure-fed from the oil pump 71 according to the moving distance.

That is, when the spool 73b is not moving, the position of the oil hole in the spool 73b is
The port to which the oil passage 81 is connected is closed. When the spool 73b moves, the oil passage 81 moves to the oil passage 8
Brake oil starts to flow into 2,83. in this case,
In proportion to the increase in the moving distance of the spool 73b, the amount of brake oil flowing from the oil passage 81 into the oil passage 83 decreases, and the amount of brake oil flowing into the oil passage 82, due to the positional relationship of the oil holes. Increases. Note that the moving distance of the spool 73b increases in proportion to the amount of electricity supplied to the solenoid 73a.

The electromagnetic switching valve 75 is a two-position switching valve.
In the first position 75A shown in FIG. 1, the electromagnetic switching valve 75 has an oil passage 82 extending from the electromagnetic proportional pressure reducing valve 73 and a left wheel oil passage 85, and an oil passage extending to a right wheel oil passage 86 and the reserve tank 63. 87 are connected respectively. From this state, when the solenoid 75c of the electromagnetic switching valve 75 is excited, the electromagnetic switching valve 75 is switched to the second position 75B. At the second position 75B, the oil passage 82 and the right wheel oil passage 86 are connected, and the left wheel oil passage 85 and the oil passage 87 are connected.

The right oil passage 86 is connected to the first port 22.
The brake oil can be supplied to the right wheel-side first control pressure chamber 37R via f, and the left wheel-side oil passage 85 can supply brake oil to the left wheel-side first control pressure chamber 38L via the second port 22g. The controller 7 has a ROM, R (not shown)
A storage device such as an AM, a central processing unit, an input / output device, and the like are built in. On the input side of the input / output device, various sensors 91, for example, a steering angle sensor for detecting a steering angle of a steering wheel (not shown), a vehicle speed sensor for detecting a vehicle speed, and an acceleration in a vehicle width direction are detected. A lateral G sensor, a brake switch for detecting a depression operation of the brake pedal 28, and the like are electrically connected.

The output side of the input / output device of the controller 7 is electrically connected to the solenoids 73a and 75c of the electric motor 77, the electromagnetic proportional pressure reducing valve 73, and the electromagnetic switching valve 75. Therefore, the controller 7 can control the discharge amount of the brake oil from the oil pump 71 by operating the electric motor 77. Also, the solenoid 73a of the electromagnetic proportional pressure reducing valve 73 is excited, and the electromagnetic switching valve 7 is turned on.
5 can be controlled. Further, the switching positions 75A, 75B of the electromagnetic switching valve 75
Can be controlled.

Next, the operation of the brake device 1 will be described. In the brake device 1, normal brake control, automatic brake control, and differential pressure brake control can be performed. First, the normal brake control will be described with reference to FIG. In FIG. 3, the S piston 48, the second brake pressure chamber 52, and the master back 27 of each brake pressure generating mechanism 12 are not shown. 4 and 5, the illustration of the S piston 48, the second brake pressure chamber 52, and the master back 27 is omitted.

When the driver steps on the brake pedal 28, the push rod 26 of the master back 27 moves the support rod 41 and the balance bar 42. Pressing rods 43 are rotatably connected to both ends of the balance bar 42. Each of the pressing rods 43 is arranged at a position equidistant from the support rod 41. Move without swinging with respect to. Accordingly, the pressing rods 43 move to the same position, and push the operating rods 14 and 15 by the same distance. As a result, the P pistons 47 and the like move forward to the same position, and the same brake pressure P is applied to the right wheel side and the left wheel side.
_R and P _L are generated.

The moving distance of the balance bar 42 changes according to the amount of depression of the brake pedal 28. Thus, the brake pressure P _R generated in the brake pressure chamber 51,
The magnitude of P _L is proportional to the amount of depression of the brake pedal 28. Thus, in FIG. 6, as shown by the characteristic A, the left and right brake pressure P _R, P _L is equal to rise. Next, the automatic brake control will be described with reference to FIG. The controller 7 performs this automatic brake control, for example, when the vehicle is turning and the brake pedal 28 is not operated.

When, for example, only the right wheel side disc brake mechanism 65 is operated, the controller 7 switches the electromagnetic switching valve 75 to the second position 75B and simultaneously controls the spool 73b of the electromagnetic proportional pressure reducing valve 73 to the required braking force. Move by the distance according to. Therefore, this spool 73b
Is supplied to the right wheel side oil passage 86, and flows into the right wheel side first control pressure chamber 37R through the first port 22f.

The oil that has flowed into the right wheel side first control pressure chamber 37R moves the first control piston 34 and the first operating rod 14 forward and at the same time through the first oil passage 22d. The second control piston 35 flows into the second control pressure chamber 38 </ b> R and discharges the oil in the left-wheel first and second control pressure chambers 38 </ b> L and 37 </ b> L to the left-wheel oil passage 85.
And the second operation rod 15 is moved back.

In this case, since the forward movement distance of the first operation rod 14 is equal to the backward movement distance of the second operation rod 15, the balance bar 42 does not move relative to the first constituent member 21. The support rod 41 swings in the direction of arrow CC in the figure, and therefore does not move. 1st operation rod 1
When 4 is forward, etc. P piston 47 is pushed, the braking pressure P _R of the right wheel side is generated. On the other hand, when the second operating rod 15 returns, the P piston 47 and the like are pushed back by the return springs 54 and 55 and the like. After the like P piston 47 is pushed back to a predetermined position, the operating rod 15 is backward while spaced from the P piston 47, therefore, it does not affect the left wheel brake pressure P _L.

The controller 7 adjusts the amount of current supplied to the solenoid 73a of the electromagnetic proportional pressure reducing valve 73,
By manipulating the movement amounts of 4, 15 and the generated brake pressure P _R
Can be changed. Therefore, in FIG.
As shown by characteristic B, only the right wheel brake pressure P _R is increased. When only the left wheel side disk brake mechanism 65 is operated, the electromagnetic switching valve 75 is moved to the first position 75.
A, and oil may be supplied into the left wheel side first control pressure chamber 38L via the second oil passage 22e.

Next, the differential pressure brake control will be described. In the differential pressure brake control, there are a case where automatic braking is performed during normal braking and a case where normal braking is performed during automatic braking. First, a case where the controller 7 performs, for example, automatic braking on the right wheel side from a state in which the driver is operating the brake pedal 28 (solid line state in FIG. 3) will be described.

In this case, the first operating rod 14 is positioned at a position corresponding to the amount of depression of the brake pedal 28 (the position indicated by the solid line in FIG. 3).
And the second operation rod 15 returns from a position corresponding to the amount of depression of the brake pedal 28. Therefore, as shown by the solid line in FIG.
Forward distance increases the brake pressure P _R of the right wheel side increases equal, the braking pressure P _L of the left wheel side forward distance such Hidariwagawa P pistons 47 is reduced is lowered. Each operating rod 14,1
5, since it is connected by the balance bar 42, and the amount of change in Hidariwagawa brake pressure P _L, the amount of change in right wheel brake pressure P _R is equal.

Accordingly, the brake pressure characteristic in this case is, as shown by the characteristic D in FIG.
P _R, P _L each braking pressure of the right and left wheel side by but is operated
Rise equally. Then, the characteristic changes from the time when the automatic brake control of the right wheel side is conducted, while increasing the right wheel brake pressure P _R continues Hidariwagawa brake pressure P _L starts to fall. In this case, the left and right brake pressure P _R, the sum of P _L, is the same as the sum of the left and right brake pressure P _R, P _L of the case shown by the characteristic A.

Next, the case where the driver operates the brake pedal 28 from the state where the controller 7 is performing the automatic braking on the right wheel side (the solid line state in FIG. 4) will be described. In this case, the support rod 41 and the balance bar 42
Is moved by being pushed by the push rod 26. The balance bar 42 is connected to the support rod 41 at its center position, and the pressing rods 43 are disposed equidistant from each other with respect to the support rod 41. It moves while maintaining the swing angle with respect to 41, and moves each pressing rod 43 by the same distance from each other. Therefore, the operating rod 15 is moved forward from the position were the automatic brake control (solid line position of FIG. 4), the brake pressure P _R of the left and right by an amount corresponding to the forward movement distance, the P _L increases .

[0040] Thus, the brake pressure characteristic in this case, in FIG. 6, as shown by the characteristic E, first, only the right wheel brake pressure P _R is increased by being automatic brake control. Then, the characteristic changes from the time when the brake pedal 28 is depressed, the left and right brake pressure P _R, is P _L increases in equal proportions to each other. In the present embodiment, the stopper that regulates the swing angle of the balance bar 42 uses the distal end surface 21 e of the sleeve 21 d of the first component member 21, but is not limited thereto. For example, as the stopper, as shown in FIG. 7, a central stopper 71 protruding from the support rod 41, or as shown in FIG.
The left and right stoppers 72 fixed to the disk portion 21a of the component member 21 may be used.

[0041]

As described above, according to the present invention,
The brake device of the vehicle is configured such that the brake pressure pistons for respectively generating the left and right wheel brake pressures, a pair of operation rods for moving the respective brake pressure pistons, and the brake pedal operation force are equally applied to the respective operation rods. And a brake force difference control means for increasing and decreasing the moving distance of each operating rod, and the connecting means is pivoted at the center position to the brake pedal and at both ends to each operating rod. A swinging member that is freely connected, and further comprising a pair of control pistons provided on each operation rod, the brake force difference control means, one side of one control piston and the other side of the control piston. A first fluid pressure circuit capable of supplying fluid pressure to the other side of the piston, and fluid pressure supplied to the other side of one control piston and one side of the other control piston It was constructed and a second hydraulic circuit that can. Therefore, there is an excellent effect that the braking force difference control of the left and right wheels can be performed without being affected by the presence or absence of the brake operation by the driver.

[Brief description of the drawings]

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

FIG. 2 is a sectional view of the master cylinder unit 3 of FIG.

FIG. 3 is a schematic configuration diagram illustrating an operation state of a master cylinder unit 3 when normal brake control is performed.

FIG. 4 is a schematic configuration diagram showing an operation state of a master cylinder unit 3 when automatic brake control is performed.

FIG. 5 is a schematic configuration diagram showing an operation state of a master cylinder unit 3 when normal brake control and automatic brake control are performed simultaneously.

[6] the left and right brake pressure P _R, which is a diagram showing characteristics of a P _L.

FIG. 7 is a schematic configuration diagram showing another embodiment of a stopper that limits the swing angle of the balance bar 42.

FIG. 8 is a schematic configuration diagram showing still another embodiment of a stopper for limiting the swing angle of the balance bar 42.

[Explanation of symbols]

 Reference Signs List 1 brake device 3 master cylinder unit 7 controller 14, 15 operating rod 28 brake pedal 34, 35 control piston 42 balance bar 47 primary piston 48 secondary piston 85 left wheel oil passage 86 right wheel oil passage

Claims (1)

(57) [Claims] 1. A brake pressure piston for generating a brake pressure for a left wheel and a brake pressure for a right wheel, an operation rod for operating each brake pressure piston, and an operation force from the brake pedal side applied to each operation rod. A connecting means for transmitting, and a braking force difference control means for increasing and decreasing the moving distance of each operation rod, the connecting means, a transmitting member for transmitting the operating force from the brake pedal side, the central position to the transmitting member, A swing member having both ends rotatably connected to the operation rods, respectively, wherein the brake force difference control means includes a control piston provided on each operation rod, one side of one control piston and A first fluid pressure circuit capable of supplying fluid pressure to a pressure chamber formed on the other side of the other control piston; Brake device for a vehicle, characterized by comprising a second fluid pressure circuit capable of supplying a fluid pressure to the pressure chamber formed in the side.