JPH01178063A - Antiskid controller - Google Patents

Abstract

PURPOSE:To improve the safety in the case where one system is damaged, by installing a modulator which is constituted by fitting each piston into two piston chambers which communicate through a contracted diameter part and supplying a brake hydraulic pressure into the wheel cylinder for the right and left rear wheels through the modulator. CONSTITUTION:A master cylinder 12 is connected with the wheel cylinder 19 of a left rear wheel(RL) through a modulator 18 by a pipe T3, and said pipe T3 set between the master cylinder 12 and the modulator 18 is connected with the wheel cylinder of a right front wheel(FR). As for the modulator 18 pistons 23 and 30 are fitted into two piston chambers 21 and 22 which communicate through a contracted diameter part 20, and the piston rod 23a of the piston 23 is set close to the inside of the second piston chamber 22, and the communication hole 34 of the piston 30 is closed by a sealing member 29 at the top edge of the piston rod 23a. A pressure chamber 25 is connected to the pipe between the master cylinder 12 and a three-position valve 14 and a hydraulic pump 40, and a control chamber 26 is connected with a pipe between the three-position valve 14 and the wheel cylinder 13 of a right rear wheel(RR).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an anti-skid device for wheels with diagonally arranged hydraulic systems.

(Prior Art) In recent years, anti-skid devices have been installed to ensure the safety of vehicles. And front-wheel drive vehicles
1) uses diagonal piping (cross piping) in which the wheel cylinders of each wheel are diagonally piped. In this case, a so-called 4-channel system is used in which a solenoid valve is used for each wheel. Looking at the rear wheels, the solenoid valves are normally controlled simultaneously in low select (selecting the low speed side of the wheel speeds determined by the wheel speed sensors provided on the left and right wheels, respectively). Furthermore, the solenoid valve in this anti-skid device is expensive.

Against this background, a method of using one solenoid valve and controlling it simultaneously via a modulator was proposed, for example, in Japanese Patent Publication No. 48.
It is shown in the publication No.-20354. To explain this technical concept based on Fig. 4, there are three positions in the piping from the master cylinder 1 to the wheel cylinder 2 of the right rear (RR) wheel that can be switched to pressure increase position a, holding position, and pressure reduction position C. A valve 3 is installed, and the left rear (from the master cylinder 1)
RL) A modulator 5 is disposed in the middle of the piping to the wheel cylinder 4 of the wheel. Two valve chambers 6.7 are formed in the modulator 5 and communicate with each other, and a check valve 8 consisting of a valve seat 8a, a valve body 8b, and a spring 8C is arranged in the valve chamber 6 connected to the master cylinder 1. With,
A piston 9 with a spring 9a is arranged in the valve chamber 7, and two compartments 7b and 7a separated by the piston 9 are used for the wheel cylinder 4 of the left rear (RL) wheel and the right rear (R) wheel cylinder 4.
R) is connected to the wheel cylinder 2 of the wheel.

When the master cylinder 1 is pressurized when the 3-position valve 3 is at the pressure increase position a, the right rear (RR>
At the same time, the pressure in the wheel cylinder 2 of the wheel is increased, and the pressure in the wheel cylinder 4 of the left rear (RL) wheel is increased by the open check valve 8 through the valve chamber 6 and compartment chamber 7b of the modulator 5, and the brake is applied. Then, when the 3-position valve 3 switches to the pressure reducing position C, the wheel cylinder 2 of the right rear (RR) wheel
Pressure oil is discharged to the reservoir 10 via the 3-position valve 3, and the pressure in the compartment 7a of the modulator 50 is reduced, causing the piston 9 to move to the left in the figure and move to the left rear (RL).
) The oil pressure in the wheel cylinder 4 of the wheel is reduced to prevent the wheel from skidding.

(Problem to be solved by the invention) However, when such a method is used, if one of the two hydraulic circuits is damaged, the brakes of the other systems may be adversely affected. For this reason, it was necessary to provide a safety valve.

(Objective of the Invention) An object of the present invention is to solve the above-mentioned problems and provide an anti-skid device that can apply the brakes on other systems even if one system is damaged without providing a safety valve.

(Means for Solving the Problems) In order to achieve the above object, this invention has two hydraulic circuits that diagonally communicate the wheel cylinders that adjust the braking force of each wheel, and a hydraulic circuit that adjusts the braking force of each wheel. A master cylinder that supplies pressurized oil to each of the two hydraulic circuits and a hydraulic circuit of one of the two hydraulic circuits are provided, and when increasing the pressure of the wheel cylinder, the hydraulic circuit of this system is installed. An anti-skid control device comprising a switching means which is switched to communicate the master cylinder and the wheel cylinder, and which is switched to discharge the pressure oil of the wheel cylinder of this system when the pressure of the wheel cylinder is reduced. First and second piston chambers are formed that communicate with each other via a diameter portion, and a first piston whose rod portion moves W1 in the reduced diameter portion is slidably disposed in the first piston chamber. A second piston having a communication hole communicating with the second piston chamber is slidably disposed in the second piston chamber, and a second piston is slidably disposed in the first piston chamber. a biasing means for biasing the second piston in a direction of 1Ili relative to the second piston;
A biasing means for biasing the second piston toward the first piston is disposed in the piston chamber, and a biasing means for biasing the second piston toward the first piston is disposed at the tip of the rod portion of the first piston in the second piston chamber. A sealing member facing the communication hole of the second piston is provided so as to be always spaced apart from the second piston, and the first and second piston chambers are partitioned by the first and second pistons. Four compartments are provided between the master cylinder of one of the two hydraulic circuit systems and the switching means, between the switching means of one of the systems and the wheel cylinder, and between the wheel cylinder of the other system. The gist of this is an undeskid device connected to the master cylinder of the other system.

(Function) When increasing the pressure in the wheel cylinder, the pressure oil in the master cylinder is increased through the switching means in the first system, and the second system is communicated through the communication hole in the second piston. The pressure is increased through the second piston chamber. When the pressure of the wheel cylinder is reduced, the pressure oil of the wheel cylinder of the first system is discharged through the switching means, and both compartments of the first piston to which the master cylinder oil pressure and the wheel cylinder oil pressure are applied. The compartment chamber communicating with the rear wheel cylinder is depressurized, the first piston moves toward the second piston, and the sealing member seals the communication hole of the second piston, and is further provided in the second piston chamber. When the first piston rod moves the second piston against the urging force of the urging means, the pressure in the wheel cylinder of the second system communicating with one compartment of the second piston chamber is reduced by 6". .

Furthermore, even if the first system is lost, both biasing means will maintain the first system.
The sealing member of the piston and the second piston are maintained in a separated state, and the second system is in communication with the second system through the communication hole, so that the second system can be used. The first piston maintains its position by the biasing means provided in the first piston chamber, and the first system can be used.

(Example) An example embodying the present invention will be described below with reference to the drawings.

A wheel cylinder 13 for the right rear (RR) wheel is connected to a master cylinder 12 that is activated by operating the brake pedal 11 via a hydraulic pipe T1. A 3-position valve 14 as a switching means is disposed in the middle of this pipe T1.
The position valve 14 connects the plumber 1 at the pressure increasing position a, holds the hydraulic oil of the plumber 1 at the holding position, and connects the hydraulic oil of the plumber 1 to the right rear (RR) through the hydraulic plumber 2 at the pressure reducing position C. The hydraulic oil in the wheel cylinder 13 of the wheel is discharged into a reservoir 15. This three-position valve 14 can be switched to each position a to C by a signal from a controller 16.

Roughly speaking, a check valve 17 is connected in parallel to the three-position valve 14.

Further, the hydraulic plumber 1 between the master cylinder 12 and the three-position valve 14 is connected to a wheel cylinder (not shown) of the front left (FL) wheel.

Further, the master cylinder 12 is connected to the wheel cylinder 19 of the left rear (RL) wheel via the modulator 18 by a hydraulic piping T3, and the piping T3 between the master cylinder 12 and the modulator 18 is connected to the right front (FR) wheel cylinder 19. It is connected to the wheel cylinder (not shown) of the wheel.

To explain this modulator 18 in detail, a piston chamber is formed in the housing H of the modulator 18, and the piston chamber communicates with the first piston chamber on the left side through a reduced diameter portion 20 in the center.
It consists of a piston chamber 21 and a second piston chamber 22 on the right side. Furthermore, a first piston 23 is movably supported in the first piston chamber 21, and a rod portion 23 of the first piston 23 is movably supported.
a extends into the second piston chamber 22 through the reduced diameter portion 20, and the 0-rad portion 23a moves around the reduced diameter portion 20. The outer circumference of this first piston 23 is O
The first piston chamber 21 is sealed by a ring 24, and the first piston chamber 21 is divided by the piston 23 into a first pressure chamber 25 as a partitioned chamber and a control chamber 26 as a partitioned chamber. Also, the reduced diameter part 20
An O-ring 27 is also disposed in the first piston 23, and the rod portion 23a of the first piston 23 is completely sealed by the O-ring 27.

Furthermore, a spring 28 is arranged in the control chamber 26 as a biasing means for biasing the first piston 23 in the left direction in the figure. Moreover, the rod portion 23 of the first piston 23
The tip of a is connected to the sealing member 2 in the second piston chamber 22.
9 are arranged.

Area S1 of the outer diameter (seal diameter) of this sealing member 29 and area S1 of the diameter (seal diameter) of the O-ring of the reduced diameter portion 20
are equal. The first piston 23 is held in the position shown in FIG. 1 by the spring 28. That is, the protrusion 23b of the first piston 23 protruding from the first pressure chamber 25 side is in contact with the side surface of the first piston chamber 21.

The second piston chamber 22 is formed with an enlarged-diameter portion, and the second piston 30 is slidably disposed in this portion via an O-ring 31. The area S2 and the area S2 at the diameter (seal diameter) of the O-ring 24 of the first piston 23 are equal. The second piston chamber 22 includes an expansion chamber 32 as a left compartment and a second pressure chamber 33 as a right compartment in this second piston 30.
It is divided into. The second piston 30 has the first
A communication hole 34 for communicating the expansion chamber 32 and the second pressure chamber 33 is formed at a position facing the seal member 29 of the piston 23 . Further, a second piston 3 is provided in the second pressure chamber 33.
A spring 35 is provided as a biasing means for biasing 0 to the left.

The second piston 30 is abutted and supported by a spring 35 at the position shown in FIG. 1, and the seal member 29 and the second piston 30 are normally separated from each other. It should be noted that the O-rings 24, 31 serving as sealing members may alternatively be cup-shaped seals.

The housing 1 of the modulator 18 has the first pressure chamber 25. Control room 26. Boats 36 to 39 are formed in which the expansion chamber 32 and the second pressure chamber 33 communicate with the outside. The boat 36 of the first pressure chamber 25 is connected to the piping between the master cylinder 12 and the three-position valve 14, and is connected to the hydraulic pump 4 that sucks up the hydraulic oil from the reservoir 15.
Connected to 0. Note that this hydraulic pump 40 is provided with check valves 41a and 41b at the front and rear.

The boat 37 of the control chamber 26 in the modulator 18 is connected to the piping between the three-position valve 14 and the wheel cylinder 13 of the right rear (RR) wheel. Further, the boat 38 of the expansion chamber 32 within the modulator 1 is connected to the wheel cylinder 19 of the right rear wheel (RL), and the boat 39 of the second pressure chamber 33 within the modulator 18 is connected to the master cylinder 12. .

Among such diagonal piping, the master cylinder 12
The system that supplies pressure oil to the wheel cylinders 13 of the front left (FL) wheel and the rear right (RR) wheel is called the first system, and the system that supplies pressure oil to the wheel cylinders 13 of the front right (FR) wheel and the rear right (RL) wheel is called the first system.
The system that supplies pressure oil to the system will be referred to as the second system.

The controller 16 inputs a signal from a wheel speed sensor (not shown) provided on each wheel, and calculates each wheel speed, each wheel acceleration, and estimated vehicle body speed based on the signal. Then, one of the pressure reduction mode, holding mode, and increase mode is set, which provides the optimum power for the right rear (RR) wheel, and the three-position valve 14 is set at each position a-C corresponding to each mode. Switch to

Also, in Fig. 1, 42, 43, 44, and 45 are apertures,
Of these, apertures 43 and 45 are for the right rear (RR) wheel and the left rear (RL) wheel.
) It determines the hydraulic pressure rising speed of the wheel, and the throttle 42
is for keeping the pressures in the first pressure chamber 25 and control chamber 26 in the modulator 18 at the same pressure when the 3-position valve 14 is in the pressure increasing position a, so that the first piston 23 does not move to the right. .

Next, the operation of the anti-skid 5A constructed in this way will be explained.

During normal brake operation, the controller 16
The position valve 14 is located at the pressure increasing position a. When the pressure in the master cylinder 12 increases due to brake operation (by depressing the brake pedal 11), the pressure in the wheel cylinder 13 of the right rear (RR) wheel also increases via the throttle 43. At this time, the first pressure chamber 25 and the control chamber 26 of the modulator 18 have the same pressure due to the throttle 42, and the first piston 23 remains pressed leftward by the spring 28 and does not move. Therefore, the sealing member 29 does not seal the communication hole 34 of the second piston 30, and the wheel cylinder 19 of the left rear (RL) wheel also connects with the wheel cylinder 13 of the right rear (RR) wheel. Similarly, the pressure increases and the brakes are applied.

The controller 16 switches the three-position valve 14 to the holding position 1b when the wheel speed of the right rear (RR) wheel or the left rear (RL) wheel decreases with respect to the estimated vehicle speed.

At this time, the pressure in the wheel cylinder 13 of the right rear (RR) wheel is immediately maintained, and the control chamber 26 of the modulator 18
pressure is also maintained. Then, as the oil pressure of the master cylinder 12 further increases, a pressure difference is created between the first pressure chamber 25 and the control chamber 26 of the modulator 18, which causes a force pushing the first piston 23 to the right ( -(Pl
-P2) (S2-81): where Pl is the pressure in the first pressure chamber 25 and P2 is the pressure in the control chamber 26).

When this force exceeds the 1:1 force pushing the spring 28 to the left, the first piston 23 moves to the right, and the sealing member 29 comes into contact with the second piston 30 as shown in FIG. The hole 34 is sealed, the second pressure chamber 33 and the expansion chamber 32 are separated, and the pressure in the wheel cylinder 19 of the rear left (RL) wheel is maintained.

Strictly speaking, when the first piston 23 moves to the right, the volume of the control chamber 26 decreases and the pressure in the wheel cylinder 19 of the right rear (RR) wheel increases.
If the clearance between piston 9 and second piston 30 is kept small, this will not be a problem.

When the wheel speed of the right rear (RR) wheel or the left rear (RL) wheel decreases further relative to the estimated vehicle speed, the controller 16 switches the three-position valve 14 to the reduced pressure position gc. At this time, the hydraulic pressure in the wheel cylinder 13 of the right rear (RR) wheel decreases as it communicates with the right rear (RR) wheel brake reservoir 15. Therefore, the pressure in the control chamber 26 decreases, and the force pushing the first piston 23 to the right becomes stronger, exceeding the force of the spring 28.35, pushing the first piston 23 while pushing the second piston 30. 23 moves to the right. Therefore, the volume of the expansion chamber 32 increases, and the pressure in the wheel cylinder 19 of the left rear (RL) wheel P3 [= (P2 (82-81) + F1 + F2)
/((S2-81>)] also decreases.

Thereafter, even when the three-position valve 14 switches to the pressure increase position a, the holding position, and the pressure reduction position C, the first and second pistons 23, 30 are arranged so that the forces in the piston chambers of the modulator 18 are balanced.
moves, right rear (RR) wheel.

The pressure in the wheel cylinder 13.19 of the left rear (RL) wheel is increased, maintained, and decreased.

Next, consider a case where one of the diagonal piping systems (two systems) is damaged.

When a defect occurs in the first system, only a force pushing it to the left (a force due to the force F1 of the spring 28 and the pressure of the second system) is applied to the first piston 23 of the modulator 18, and the first piston 23 of the modulator 18 is The sealing member 29 and the second piston 30 are separated from each other, and the master cylinder pressure is normally transmitted to the left rear (RL>wheel) wheel cylinder 19 of the second system.

On the other hand, if a defect occurs in the second system, the first system pressure generates a force that presses the first piston 23 in the right direction. However, since the diameter of the rod portion 23a is made small, the piston 23 generated by the first pressure chamber 25 and the control chamber 26 partitioned by the first piston 23
The pressure difference between the two is small. Therefore, in the normal pressure range, the master cylinder pressure is transmitted to the wheel cylinder 13 of the right rear (RR) wheel by the force (=F1) of the spring 28 without moving the first piston 23.

As described above, in this embodiment, the first and second piston chambers 21.22 are formed in the housing H of the modulator 18, and the first and second piston chambers 21.22 communicate with each other via the diameter-reduced portion 20. A spring 28.35 is disposed to slidably support the second piston 23.30 and bias both pistons 23.30 in the same direction (left side in FIG. 1). Communication hole 3 formed in 30
A sealing member 29 is provided at the tip of the rod portion 23a of the first piston 23 that moves the diameter reducing portion 20 m relative to the piston 4. Then, each chamber (first pressure chamber 25, control chamber 26, expansion chamber 32, second pressure chamber 33) divided into the first and second pistons 23, 30 is placed in three positions with respect to the master cylinder 12 of the first system. Valve 1
Piping with 4, 3 position valve 14 and right 4! Piping with the wheel cylinder 13 of the (RR) wheel, and the wheel cylinder 19 of the left rear (RL) wheel of the second system. It was connected to the master cylinder 12.

By adopting this configuration, the wheel cylinder 13
．． 19, the pressure oil in the master cylinder 12 is increased in pressure in the first system through the three-position valve 14, and in the second system, it is increased in pressure in the communication hole 34 of the second piston 30. The pressure is increased through the communicating second piston chamber 33. When reducing the pressure in the wheel cylinder 13.19,
The pressure oil in the wheel cylinder 13 of the right rear (RR) wheel is discharged via the 3-position valve 14, and the pressure oil is discharged from the master cylinder 12.
The control chamber 26 that communicates with the wheel cylinder 13 of the right rear (RR) wheel of the first pressure chamber 25° control chamber 26 to which the hydraulic pressure of the wheel cylinder 13 of the right rear (RR) wheel is applied is depressurized. The first piston 23 is the second piston 3
0, the sealing member 29 moves toward the second piston 3
The left rear (RL ) The wheel cylinder 19 of the wheel is depressurized.

Also, even if the first system is lost, the spring 28.35
As a result, the seal member 29 provided on the first piston 23 and the second piston 30 are maintained in a separated state, and the second system is brought into communication via the communication hole 34, so that the second system can be used. On the other hand, even if the second system is damaged, the first piston 23 maintains its position by the spring 28, and the first system can be used. Therefore, by using the modulator 18, which has a simple structure, even if one system is damaged, the other systems can be braked to ensure safety without providing a safety valve.

Note that this invention is not limited to the above embodiments,
It may also be implemented as shown in FIG. Namely, boat 46
The first pressure chamber 25 of the modulator 18 and the three-position valve 14 are connected via the first pressure chamber 25, and the hydraulic pressure of the master cylinder 12 is transmitted to the wheel cylinder 13 of the right rear (RR) wheel via the first pressure chamber 25. do it like this. Further, a pipe may be connected to the wheel cylinder of the front left (FL) wheel from the middle of the pipe between the first pressure chamber 25 and the three-position valve 14.

Effects of the Invention As detailed above, according to the present invention, even if one system is damaged, the brakes of other systems can be activated to ensure safety without providing a safety valve.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram of an anti-skid device embodying this invention, Fig. 2 is a diagram for explaining the movement of the modulator, Fig. 3 is a hydraulic circuit diagram of an anti-skid device for scraping, and Fig. 4 is a hydraulic circuit diagram of an anti-skid device for abrasion. FIG. 2 is a hydraulic circuit diagram of a conventional 4-nit machine. 12 is a master cylinder, 13 is a wheel cylinder for the right rear wheel, 14 is a 3-position valve as a switching means, 16 is a controller, 18 is a modulator, 19 is a wheel cylinder for the left rear wheel, 20 is a diameter reducing part, and 21 is a third cylinder. 1 piston chamber, 22
2 is a second piston chamber, 23 is a first piston, 23a is a rod portion, 25 is a first pressure chamber as a compartment, 26 is a control chamber as a compartment, 28 is a spring as a biasing means, and 29 is a A seal member, 30 is a second piston, 32 is an expansion chamber as a compartment, 33 is a second pressure chamber as a compartment, 34 is a communication hole, 35 is a spring as a biasing means, 36 is a boat, and 37 is a seal member. 38 is a boat, 39 is a boat, and H is a modulator housing.

Claims (1)

[Scope of Claims] 1. Two hydraulic circuits that diagonally communicate wheel cylinders that adjust the braking force of each wheel, and supplying pressure oil to each of the two hydraulic circuits according to brake operation. It is provided in a master cylinder and a hydraulic circuit of one of the two hydraulic circuits, and is switched to communicate the master cylinder of this system with the wheel cylinder when the pressure of the wheel cylinder is increased. In an anti-skid control device, the anti-skid control device is equipped with a switching means that is switched to discharge the pressure oil of the wheel cylinder of this system when the pressure of the wheel cylinder is reduced. A piston chamber is formed, a first piston whose rod portion slides on the reduced diameter portion is slidably disposed in the first piston chamber, and a second piston is slidably disposed in the second piston chamber. A second piston having a communication hole that communicates with the piston chamber is slidably disposed, and further, the first piston is attached to the first piston chamber in a direction in which it is spaced apart from the second piston. A biasing means for biasing the second piston toward the first piston is disposed in the second piston chamber; A sealing member facing the communication hole of the second piston is provided at the tip of the rod portion of the first piston in the chamber so as to be always spaced apart from the second piston, and in the first and second piston chambers. The four compartments divided by the first and second pistons are arranged between the master cylinder of one system of the two hydraulic circuits and the switching means, and also between the switching means of the one system and the wheel cylinder. a wheel cylinder of the other system;
An anti-skid device characterized in that it is also connected to a master cylinder of the other system.