JPH035338B2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Industrial Application Field The present invention provides an input hydraulic chamber communicating with an output port of a master cylinder, and a braking system communicating with a wheel brake according to the hydraulic pressure of the input hydraulic chamber. and an output hydraulic chamber for generating hydraulic pressure, and the volume of the output hydraulic chamber is configured to increase in response to supply of control hydraulic pressure from the anti-lock control means to the control chamber when the wheels are about to enter a lock state. The present invention relates to a vehicle brake hydraulic control device including a control valve means.

(2) Conventional technology Conventionally, such a brake hydraulic control device for a vehicle reduces the volume of an output hydraulic chamber according to the hydraulic pressure of an input hydraulic chamber, and generates braking hydraulic pressure to the wheel brakes accordingly. During control, the volume of the output hydraulic chamber is forcibly increased by the control hydraulic pressure supplied to the control chamber, thereby lowering the braking hydraulic pressure.

(3) Problems to be Solved by the Invention In the conventional device described above, the amount of volume reduction required in the output hydraulic chamber is set so that the braking hydraulic pressure can be increased from a non-braking state to a practically sufficient hydraulic pressure during braking. , its value was relatively large.

Therefore, the first object of the present invention is to reduce the required volume in the output hydraulic chamber by directly supplying hydraulic pressure from the master cylinder to the output hydraulic chamber when the volume reduction amount of the output hydraulic chamber reaches a set value. To provide a vehicle brake hydraulic pressure control device capable of reducing the amount of decrease by sufficiently reducing the hydraulic pressure during anti-lock control.

By the way, in the above-mentioned conventional hydraulic control device, in order to detect a hydraulic failure in the hydraulic system on the wheel brake side, in addition to the differential pressure failure detection means provided in the hydraulic control device that does not have an anti-lock control mechanism, each wheel brake is A stroke switch is provided for each hydraulic system. However, in order to achieve the above first objective, in a system in which hydraulic pressure from the master cylinder is directly supplied to the output hydraulic pressure chamber, if the differential pressure failure detection means is used, the pressure on the master cylinder side and the wheel brake side It is possible to detect each oil pressure failure.

In view of the above-mentioned circumstances, in addition to the first object, the second object of the present invention is to reduce oil pressure according to the differential pressure between both input hydraulic chambers connected to a pair of output ports of a tandem master cylinder. It is an object of the present invention to provide a brake hydraulic control device for a vehicle capable of detecting a hydraulic failure in each hydraulic system on a master cylinder side and a wheel brake side using a failure detecting means for detecting a failure.

B. Structure of the Invention (1) Means for Solving the Problems According to the first invention, the first cylinder part and the second cylinder part are provided concentrically in the casing of the control valve means via a partition wall. A first piston that defines an input hydraulic chamber on the partition wall side and defines the control chamber on the opposite side of the partition wall is slidably fitted in the first cylinder portion, and a first piston that defines the control chamber on the side opposite to the partition wall is slidably fitted in the second cylinder portion. A second piston defining an output hydraulic chamber is slid together;
The first and second pistons are respectively fixed to both ends of a piston rod that oil-tightly and movably penetrates the partition wall, and the partition wall has a distance between the second piston and the partition wall that is a set value. A valve mechanism is provided that communicates between the input hydraulic chamber and the output hydraulic chamber when the following conditions occur.

According to the second invention, in addition to the configuration of the first invention, there is a hydraulic pressure failure between the input hydraulic chambers communicating with each output port of the tandem master cylinder according to the differential pressure between the input hydraulic chambers. Failure detection means is provided for detecting.

(2) Effect In the first invention, when the volume within the output hydraulic chamber becomes equal to or less than a certain value, the input hydraulic chamber and the output hydraulic chamber are communicated with each other.

In the second invention, since the failure detection means detects the differential pressure between both input hydraulic chambers, when the input hydraulic chamber and the output hydraulic chamber are in communication, each hydraulic system on the master cylinder side and the wheel brake side Hydraulic pressure failure is detected.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, oil passages 2a and 2b extend from a pair of output ports 1a and 1b of a tandem type master cylinder M. These oil passages 2a, 2b are connected to control valve means 3a, 3b provided corresponding to the left and right wheels. These control valve means 3a, 3b have the same structure, and only the portions related to one control valve means 3a will be described in detail below.

A control valve means 3a is provided between the oil passage 2a and the oil passage 4 leading to the wheel brake B. The casing 5 of the control valve means 3a has an end wall 6 at one end.
A hole 7 is formed which is closed with a hole 7 and whose other end is open, and a stepped portion 8 facing the other end is provided in the middle of the hole 7. A cylindrical partition member 9 with a bottom is inserted into the hole 7 from the other end with O-rings 10 and 11 interposed between it and the inner surface of the hole 7 . Moreover, the partition member 9 is fitted into the hole 7 until the bottom part as the partition wall 12 contacts the stepped portion 8, and the cap 13 is screwed into the open end of the hole 7 until it contacts the open end of the partition member 9. It can be tightened. In this way, a first cylinder section 14 between the end wall 6 and the partition wall 12 and a second cylinder section 15 between the partition wall 12 and the cap 13 are provided concentrically in the casing 5 with the partition wall 12 in between. It will be done.

A first piston 16 is slidably connected to the first cylinder portion 14 . An input hydraulic pressure chamber 17 is defined between the first piston 16 and the partition wall 12, and the input hydraulic pressure chamber 17 is communicated with the oil passage 2a via an inlet oil passage 18 bored in the side surface of the casing 5. Ru. Also the first
A control chamber 19 is defined by the first piston 16 and the end wall 6 on the opposite side of the input hydraulic chamber 17 with respect to the piston 16 . Moreover, a spring 20 is housed in the control chamber 19, and the spring force of the spring 20 urges the first piston 16 toward the partition wall 12.

A second piston 21 is slidably connected to the second cylinder portion 15 . An output hydraulic pressure chamber 22 is defined between the second piston 21 and the partition wall 12, and the output hydraulic pressure chamber 22 is connected to the output hydraulic pressure chamber 22 via an outlet oil passage 23 provided across the side wall of the partition member 9 and the casing 5. It is communicated with the oil passage 4. Further, an open oil chamber 24 is defined between the second piston 21 and the cap 13, and this open oil chamber 24 is connected to the open oil chamber 24 via an open oil passage 25 and an oil passage 26 bored in the side wall of the casing 5. and communicates with the reservoir 27 of the master cylinder M.

A small diameter hole 28 and a large diameter hole 2 are provided in the center of the partition wall 12.
9 are bored in order from the input hydraulic chamber 17 side, and a piston rod 30 that is movable by sliding in the small diameter hole 28 is inserted into both holes 28 and 29. The first piston 16 is fixed to one end of the piston rod 30, and the second piston 21 is integrally installed to the other end of the piston rod 30. In addition, input hydraulic chamber 1
7 and the output hydraulic chamber 22,
On the end surface of the partition wall 12 facing the input hydraulic pressure chamber 17, a first
A sealing member 32 is pressed by a spring 31 provided between the piston 16 and the piston 16 . Furthermore, in order to achieve a seal between the output hydraulic chamber 22 and the open oil chamber 24, a sealing member 34 is pressed against the surface of the second piston 21 facing the output hydraulic chamber 22 by a spring 33 provided between the second piston 21 and the partition wall 12. . In order to achieve a seal between the input hydraulic chamber 17 and the control chamber 19, the first
Seal members 35 are attached to both sides of the piston 16 in the axial direction.

Anti-lock control means 37 is connected to the control chamber 19 via an oil passage 36 bored in the side wall of the casing 5.
is connected. This anti-lock control means 37
includes a hydraulic pressure source 38, a first electromagnetic valve 39 that is closed during normal times, and a second electromagnetic valve 40 that is open during normal times. The hydraulic pressure source 38 includes a hydraulic pump 42 that pumps a control liquid, such as pressure oil, from a reservoir 41 and an accumulator 43. An oil pressure sensor 44 is attached for this purpose.

Such an anti-lock control means 37 is conventionally known, and when a sensor (not shown) detects that the wheel W is about to enter a lock state, the second solenoid valve 40 closes and the first solenoid valve closes. 39 opens. Therefore, during normal times, the control chamber 19 is communicated with the reservoir 41, and when the wheels W are about to enter the locked state, the control hydraulic pressure from the hydraulic pressure source 38 is supplied to the control chamber 19.

Referring also to FIG. 2, the partition wall 12 of the control valve means 3a has a condition in which the distance between the second piston 21 and the partition wall 12 is equal to or less than a set value, that is, the volume reduction amount of the output hydraulic chamber 22 is equal to or less than the set value. A valve mechanism 45 is provided for opening the valve and communicating between the input hydraulic chamber 17 and the output hydraulic chamber 22 when the input hydraulic pressure chamber 17 and the output hydraulic chamber 22 are opened.

The valve mechanism 45 includes a valve hole 46 that opens on the inner surface of the large diameter hole 29 and is bored in the partition wall 12, an operating chamber 47 that communicates with the valve hole 46 and is provided in the partition wall 12, and a A valve body 48 is housed therein, and a spring 49 is housed in the working chamber 47 to bias the valve body 48 in a direction to close the valve hole 46. A conical valve seat 50 is provided at the open end of the valve hole 46 facing the working chamber 47, and the valve body 48 is formed so as to be seated on the valve seat 50. Furthermore, the valve body 48 has a protrusion 51 that penetrates through the valve hole 46 and projects from the inner surface of the large diameter hole 29.
are integrally provided. Further, the piston rod 30 has a conical shoulder portion 5 that becomes smaller in diameter toward the partition wall 12 side.
2 is provided, and this shoulder portion 52 is connected to the partition wall 12
The piston rod 30 is provided in the output hydraulic chamber 22 in the middle of the piston rod 30 so that it can come into contact with the protrusion 51 when the distance between the piston rod and the second piston 21 reaches a set value.
An oil passage 53 protruding from the casing 5 communicates with the working chamber 47, and this oil passage 53 is connected to the inlet oil passage 1.
It branches from the middle of 8.

Referring again to FIG. 1, failure detection means 54 is provided between the oil passages 2a and 2b. This failure detection means 54 is conventionally known and detects oil pressure failure according to the differential pressure between the oil passages 2a and 2b, that is, the differential pressure between the input hydraulic chambers 17 of both control valve means 3a and 3b. be able to.

Next, to explain the operation of this embodiment, when the brake pedal P is not operated and the brake is not applied, the second
The piston 21 is displaced to the right by the spring force of the spring 20 until it comes into contact with the cap 13, and in the valve mechanism 45, the valve body 48 is seated on the valve seat 50 and the valve is opened.

When the brake pedal P is depressed to perform a braking operation, the braking oil pressure from the master cylinder M is supplied to the input oil pressure chamber 17, causing the first piston 16 to move toward the partition wall 12.
The volume of the input hydraulic chamber 17 is increased by pressing in the direction away from the input hydraulic pressure chamber 17. Therefore, the piston rod 30
moves to the left, and the volume of the output hydraulic chamber 22 is reduced. The braking oil pressure generated in accordance with the volume reduction of the output oil pressure chamber 22 acts on the wheel brakes B via the oil passage 4, thereby making it possible to obtain a braking force.

When the volume of the output hydraulic chamber 22 further decreases and the distance between the second piston 21 and the partition wall 12 becomes equal to or less than the set value, the shoulder portion 52 of the piston rod 30 closes to the valve body 48.
The valve body 48 resists the spring force of the spring 49 and moves away from the valve seat 50 to open the valve. Therefore, the input hydraulic chamber 17 and the output hydraulic chamber 22 communicate with each other via the valve mechanism 45, and the master cylinder M
Since the hydraulic pressure from the master cylinder M is directly supplied to the output hydraulic chamber 22, the volume of the output hydraulic chamber 22 does not decrease any further, and the wheel brake B is operated by the hydraulic pressure from the master cylinder M.

When the wheels W are about to lock in this state, control hydraulic pressure is supplied to the control chamber 19, and the first piston 16 is forcibly moved toward the partition wall 12. Therefore, the piston rod 30 moves to the right, the contact between the shoulder portion 52 and the protrusion 51 of the valve body 48 is removed, and the valve body 48 is moved toward the valve seat 50 by the spring 49.
sit down. Therefore, the valve mechanism 45 opens, the input hydraulic pressure chamber 17 and the output hydraulic chamber 22 are cut off, and the braking hydraulic pressure in the output hydraulic chamber 22 stops increasing, preventing the wheels W from entering the locked state. be done. If the wheels W are still likely to lock even after this, the piston rod 30 moves further to the right, the volume of the output hydraulic pressure chamber 22 increases, and the braking hydraulic pressure decreases. This reliably prevents the wheels W from entering the locked state.

Here, it is assumed that a hydraulic pressure failure occurs in the hydraulic system from the output hydraulic chamber 22 to the wheel brake B.
In this case, when a braking operation is performed, the input hydraulic pressure chamber 17
As the oil pressure increases, the piston rod 30 moves to the left, and the valve body 48 is pushed up by the shoulder 52 of the piston rod 30 to open the valve. Therefore, the input hydraulic chamber 17 and the output hydraulic chamber 22 are communicated with each other, and the hydraulic system from the input hydraulic chamber 17 to the master cylinder M is also in a state similar to a failure. As a result, in the failure detection means 54, a pressure difference is generated between the oil passages 2a and 2b, so that it becomes possible to detect a hydraulic failure.

C. Effects of the Invention As described above, according to the first invention, the first cylinder part and the second cylinder part are provided concentrically in the casing of the control valve means with the partition wall interposed therebetween, and the first cylinder part A first piston that defines an input hydraulic chamber on the partition wall side and defines the control chamber on the opposite side of the partition wall is slid together, and a second cylinder portion defines an output hydraulic chamber on the partition wall side. A second piston is slidably connected, and the first and second pistons are respectively fixed to both ends of a piston rod that oil-tightly and movably penetrates the partition wall, and the partition wall is provided with the second piston rod.
Since a valve mechanism is provided that communicates between the input hydraulic chamber and the output hydraulic chamber when the distance between the piston and the partition wall becomes less than a set value, the amount of volume reduction required in the output hydraulic chamber is controlled by anti-lock control. The oil pressure drop required in the chamber can be suppressed to a sufficiently small value, thus contributing to miniaturization of the control valve means.

According to the second invention, in addition to the configuration of the first invention, a hydraulic pressure is applied between both input hydraulic chambers communicating with each output port of the tandem master cylinder according to the differential pressure between both input hydraulic chambers. Since a failure detection means for detecting a failure is provided, in addition to the effects of the first invention, the conventional stroke switch is omitted and a failure of hydraulic pressure in each hydraulic system on the master cylinder side and wheel brake side can be detected. It becomes possible to do so.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a diagram showing a longitudinal section of the control valve means and the hydraulic system;
FIG. 2 is an enlarged view of a portion of FIG. 1. 1a, 1b... Output port, 3a, 3b... Control valve means, 5... Casing, 12... Partition wall, 1
4...First cylinder section, 15...Second cylinder section, 16...First piston, 17...Input hydraulic chamber, 19...Control chamber, 21...Second piston, 2
2... Output hydraulic chamber, 30... Piston rod, 37...
... Antilock control means, 45 ... Valve mechanism, 54
...Failure detection means, B...Wheel brake, M...
Master cylinder, W...wheel.

Claims (1)

[Claims] 1. An input hydraulic chamber communicating with the output port of the master cylinder, and an output hydraulic chamber communicating with the wheel brake and generating braking hydraulic pressure according to the hydraulic pressure in the input hydraulic chamber, and the wheels are in a locked state. In a vehicle brake hydraulic control device comprising a control valve means configured to increase the volume of an output hydraulic pressure chamber in accordance with the supply of control hydraulic pressure from the antilock control means to the control chamber when the antilock control means attempts to enter the control chamber, the control valve In the casing of the means, a first cylinder part and a second cylinder part are provided concentrically with a partition wall in between, and the first cylinder part defines an input hydraulic chamber on the partition wall side and an input hydraulic pressure chamber on the opposite side to the partition wall. A first piston that defines the control chamber is slid onto the second cylinder portion, and a second piston that defines an output hydraulic chamber on the partition wall side is slid onto the second cylinder portion. The partition wall is provided with an input hydraulic chamber and A vehicle brake hydraulic control device characterized by being provided with a valve mechanism that communicates between output hydraulic chambers. 2. It has an input hydraulic chamber that communicates with the output port of the tandem master cylinder, and an output hydraulic chamber that communicates with the wheel brakes and generates braking hydraulic pressure according to the hydraulic pressure in the input hydraulic chamber, so that the wheels try to enter a lock state. The vehicle is provided with control valve means for each of the pair of output ports of the tandem master cylinder, the control valve means being configured to increase the volume of the output hydraulic pressure chamber in accordance with the supply of control hydraulic pressure from the anti-lock control means to the control chamber. In the brake hydraulic control device for the vehicle, a first cylinder portion and a second cylinder portion are provided concentrically in the casing of each of the control valve means via a partition wall, and the first cylinder portion has an input to the partition wall side. A first piston that defines a hydraulic chamber and defines the control chamber on the opposite side of the partition wall is slid together, and the first and second pistons have opposite ends of a piston rod that penetrates the partition wall in an oil-tight and movable manner. a valve mechanism is provided in the partition wall that communicates between the input hydraulic chamber and the output hydraulic chamber when the distance between the second piston and the partition wall becomes equal to or less than a set value; A brake hydraulic control device for a vehicle, characterized in that a failure detection means for detecting a failure of oil pressure according to the differential pressure between the two input hydraulic chambers is provided between the input hydraulic chambers of both the control valve means.