JPH0620868B2 - Vehicle brake hydraulic control device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a brake hydraulic pressure control device for a vehicle in which a hydro booster mechanism and an antiskid control device are combined.

[Conventional technology]

Conventionally, as a device used in a brake system for vehicle braking, a hydro booster as a booster mechanism, an anti-skid control device for preventing wheel lock during braking, a fail-safe mechanism, etc. have been proposed variously. However, these are generally configured as individual devices.

However, since these are built into one system called the vehicle brake, if these are combined well into an integrated unit, the workability of assembling into the vehicle will be advantageous, and further structural, If a functional improvement is achieved, its usefulness will be extremely great.

In recent years, from the viewpoint of improving the braking safety of the vehicle, the brake hydraulic pipe is divided into two independent systems such as X pipes or front and rear wheel pipes, and even when one system fails, the other system can provide a certain braking force or more. The type of vehicle that secures

[Problems to be Solved by the Invention]

The present invention has been made in view of the above circumstances, and an object thereof is to provide a brake hydraulic pressure control device that is suitably applied to a vehicle having an X piping type brake hydraulic pressure pipe.

Another object of the present invention is to provide anti-skid control before
By controlling the wheel and the rear two wheels separately, it is possible to provide a relatively inexpensive anti-skid control device.

[Means for Solving the Problems]

Thus, the feature of the brake hydraulic pressure control device for a vehicle according to the present invention, which has been made to realize the above-mentioned object, is that the brake hydraulic pressure control used for the brake hydraulic pressure system in which the brake hydraulic pressure system of the four-wheeled vehicle has two X piping systems. A main cylinder device incorporating a hydro booster mechanism for transmitting a control hydraulic pressure depending on a stepping force to a brake pedal and a fail-safe hydraulic pressure generating mechanism for generating at least one fail-safe hydraulic pressure of the two systems, The brake hydraulic pressure piping for branching control hydraulic pressure of the hydro booster mechanism into two directions, one of which is transmitted to each front wheel side braking device of the two systems and the other of which is transmitted to each rear wheel side braking device of the two systems, Connect the fail-safe hydraulic pressure from the fail-safe mechanism to the brake hydraulic pipe of the corresponding system, and In the event of failure, the auxiliary cylinder device that incorporates the valve device that transmits the fail-safe oil pressure to the corresponding brake device of the system and the two branched brake oil pressure pipes that the control oil pressure transfers are interposed between the auxiliary cylinder device and the anti-skid signal. As an input, depressurize, pressurize the hydraulic pressure on the brake device side,
Alternatively, it is configured to include a solenoid valve device for anti-skid control which is held as necessary.

[Action]

According to the configuration of the present invention described above, the main cylinder device has a built-in fail-safe hydraulic pressure generation mechanism and two sub-cylinder devices (or four fail-safe countermeasure type four-devices when the hydro-booster mechanism has a hydraulic defect). Secondary cylinder device)
It is possible to prevent a no-brake condition by and the anti-skid control can be controlled by a combination of these sub-cylinder device and four solenoid valves, so that it is possible to secure a mechanism or device having a plurality of functions.

Embodiments of the Invention The present invention will be described below based on embodiments shown in the drawings.

Embodiment 1 In Embodiment 1 shown in FIG. 1, the four wheels of the vehicle are set to the front right (F
tR) -rear left (RrL) and front left (FtL) -rear right (RrL)
In the case where an independent X-type brake hydraulic pipe is provided in the two systems (R), a system in which a fail-safe mechanism is added to the FtL-RrR system is shown.

The device of this example includes a hydro booster mechanism and FtL-Rr.
Brake hydraulic piping 100 for branching and transmitting the control hydraulic pressure from the main cylinder device 1 incorporating the fail-safe hydraulic pressure generation mechanism for the R system and the hydro booster mechanism to each front wheel braking device of two systems and each rear wheel braking device of two systems -10
5. Anti-skid control solenoid valve devices 300 and 300 'interposed in the middle of pipes 101 and 101' for each system branched for the front and rear wheels, and brake hydraulic pressure transmission pipes for the FtL-RrR system It is composed of a combination of sub-cylinder devices 200L and 200R which are provided in the middle of each.

Hereinafter, each of these devices and connection relationships will be sequentially described.

Main Cylinder Device 1 This main cylinder device 1 has cylinder parts I and II in which a hydro booster mechanism and a fail-safe mechanism are incorporated in a cylinder body 1a.

First, the configuration of the I-th cylinder portion will be described. This is the push rod 2 fitted into the small diameter cylinder portion from one end opening of the cylinder body 1a, and the outer peripheral portion of the fitting inner end portion of the push rod 2. And a control piston 3 fitted in the large-diameter cylinder portion is housed, and a brake pedal (not shown) connected to an outer end portion of the push rod 2 by cooperation of the push rod 2 and the control piston 3. The pressure control valve is configured to determine the transmission oil pressure level from the accumulator 14 that is the pressure accumulation source, in accordance with the stepping force to ().

That is, the control piston 3 has a radial passage 3 a that guides the pressure oil from the accumulator 14 to the inner peripheral surface of the inner cylinder of the push rod 2 through the oil chamber A, and the other push rod 2 At the inner end of the control piston 3
Is provided with a radial passage 2a that is open to the inner peripheral surface of the inner cylinder. Both of these radial passages 2a and 3a are in a non-communication state in which they do not face each other as shown in the figure at normal times (when not braking), but they are pushed. When the rod 2 moves relative to the control piston 3 when the brake pedal is stepped on (during braking), the rod 2 moves to the facing position and becomes the communication position of the radial passages 2a and 3a, and the pressure oil from the accumulator 14 is released. It is adapted to be transmitted to the radial passage 2a of the push rod 2.

The radial passage of the push rod 2 is designed to be output downstream via the stepped oil chamber B of the small-diameter cylinder portion via the longitudinal passage 2b of the axial center portion. Acts in the direction opposite to the pushing of the push rod 2 to give a stepping reaction force to the brake pedal.

The control piston 3 is biased to the initial position shown by a lightly loaded return spring 4 stretched between the control piston 3 and the inner wall of the cylinder body, and the push rod 2 is moved outward from the I-th cylinder by a return spring 5. It is designed to get out. Reference numeral 6 is a locking ring that defines the limit of the push rod 2 coming out.

Further, the push rod 2 and the control piston 3 are normally in communication with each other, and are provided with radial passages 2c and 3b for releasing pressure which are released from the communication when braking. When the brake is released, the hydraulic pressure in the stepped oil chamber B is released to the reservoir side, which will be described later, through the release oil chamber C.

As described above, the hydro booster mechanism housed in the I-th cylinder is in the non-brake state.
The hydraulic oil from the stepped oil chamber B is released, the hydraulic pressure in the stepped oil chamber B is released, and the pressure release in the stepped oil chamber B is shut off at the time of braking. Will be transmitted to the stepped oil chamber B.

Next, the fail-self mechanism housed in the No. II cylinder section will be described. This mechanism of this example is of the master cylinder type, and has a hydraulic piston 7 that moves substantially integrally with the control piston 3 and this hydraulic piston. It has a return spring 8 engaged with the piston 7, and functionally, when the hydraulic piston 7 receives an external force and moves leftward in the drawing, the cup seal 9 closes the competition port 10 and the oil chamber F. This will generate hydraulic pressure. Reference numeral 11 is an intake port. Further, 12 and 13 are reservoirs. Oil chamber F
The oil chamber is generated when the push rod 2 directly presses the hydraulic piston 7 via the control piston 3 as described above. Therefore, this is a countermeasure against the failure of the system of the accumulator 14. Therefore, in this example, when the push rod 2 is moved directly beyond the stroke range for the direct pressing of the control piston 3 by the push rod 2 to function as a pressure control valve, its shoulder 2d engages with the control piston 3. It is done by doing.

Sub-cylinder devices 200, 200 'One sub-cylinder device is provided for each brake hydraulic pressure transmission pipe to each brake device of the FtL-RrR system, and both have the same structure. Therefore, only the FtL system will be described, and the RrR system will be shown with a dash added to the same equal sign. The function of this sub-cylinder device is to transmit the brake oil pressure to the brake device in proportion to the control oil pressure in the stepped oil chamber B of the hydro booster mechanism during normal braking, and at the time of fail-safe (when the accumulator or the like is defective). Is provided as a mechanism that cuts off the control hydraulic pressure transmission from the accumulator and proportionally generates the brake hydraulic pressure by the hydraulic pressure (oil chamber F) generated by the fail-safe hydraulic pressure generation mechanism.

The switching of the hydraulic pressure transmission during the normal braking and the fail-safe operation is configured by a combination of a power piston mechanism and a switching valve that operates in conjunction with the power piston mechanism. That is, a hydraulic piston 202 is slidably fitted in the sub-cylinder 201, one end of the hydraulic piston 202 faces the oil chamber G communicating with the oil chamber F which is the fail-safe oil chamber, and the other end thereof brakes. It faces a brake fluid chamber E communicating with the device (wheel cylinder), and a switching valve 203 is built in the hydraulic piston 202. A power piston mechanism, which is pressure-divided with the hydraulic piston 202 in the sub cylinder, is linked, and the power piston 208 in the power cylinder 207 has a control hydraulic pressure (transmitted hydraulic pressure from the stepped oil chamber B). The hydraulic piston 202 is pressed in the direction of the brake fluid chamber E by a hydraulic acting force proportional to.

The switching valve 203 is configured to open when the hydraulic piston 202 shown in the figure is stationary, and to close the communication passage between the oil chambers E to G when the hydraulic piston 202 is moved by the power piston 208. Yes, 203a
Is a passage thereof, 204 is a valve body ball of a switching valve, 205 is a locking rod for separating the valve body ball 204 from the valve seat at the position shown in the figure, 206 is a return spring, 205a is a set spring, 208 is a power piston, and 209 It is a return spring.

The control hydraulic pressure from the stepped oil chamber B of the hydro-booster mechanism is as follows:
The hydraulic pipe 100 is branched into 101, 101 ', and further branched and transmitted via the intermediate solenoid valve devices 300, 300'. One of the branched hydraulic pipes 101 is connected to the oil chamber D of the sub-cylinder device 200L, and the other is directly connected to the brake device of the front wheel FtR of the separate system FtR-RrL system. ing. Further, the system of the hydraulic pipe 101 'is further branched, and one side is the oil chamber D of the auxiliary cylinder device 200R.
And the other is directly connected to the brake device of the rear wheel RrL of the FtR-RrL system.

Considering the brake hydraulic system at the time of fail-safe by such a brake hydraulic pipe, this constitutes two systems of FtR-RrR and FtR-RrL, and at the time of normal braking, the system having the auxiliary cylinder device is the control hydraulic pressure of the other system. It has a structure controlled by. The anti-skid control solenoid valve devices 300 and 300 'are composed of a pair of solenoid valves that are open / close controlled by an anti-skid control circuit (not shown).
0'is a pipe 1 for transmitting hydraulic pressure from the oil chamber B to the oil chamber D or the like.
01, 101 'A normally open solenoid valve (hold valve) NO provided midway, and a normally closed solenoid valve (pressure reducing valve) for releasing the hydraulic pressure of the oil chamber D or the like to the reservoir 12 (via the oil chamber C). Valve) NC, and these two solenoid valves NO and NC are
An anti-skid signal from an anti-skid control circuit (not shown) allows selection of the modes shown in Table 1 below.

For such mode selection, a known anti-skid control circuit may appropriately employ a system in which each signal of the brake pressure reduction signal, the holding signal, and the re-pressurization signal is output according to the rotation state of the wheel.

Reference numeral 15 is a pump that pumps pressure oil from the brake oil pressure release pipe 105 to the accumulator 14, and 16 is a check valve.

The overall operation of the brake hydraulic control device having the above configuration will be summarized and described.

During normal braking By pressing the push rod 2 from the brake pedal,
The hydro booster mechanism functions to transmit the hydraulic pressure to the oil chamber B, and the push rod causes a reaction force of pressing.

The oil pressure in the oil chamber B is supplied to each sub cylinder device 200 by piping.
The brake hydraulic pressure of the FtL-RrR system is generated and transmitted to the L and 200R, and the control hydraulic pressure is directly transmitted to the FtR-RrL system as the brake hydraulic pressure.

At the time of anti-skid control If the anti-skid operation of the solenoid valve device 300 now occurs, the solenoid valve NO is first closed by an anti-skid signal (not shown), and further hydraulic pressure increase downstream of the pipes 102 and 103 is stopped, and at the same time, the solenoid valve is closed. NC is opened. Therefore, the brake oil pressure transmitted from the oil chamber B to the oil chamber D is reduced, and the braking force of the wheel FtL is reduced (see B in Table 1).

Further, the braking force of the wheel FtR, which is directly transmitted as the brake hydraulic pressure via the pipe 103, is also reduced.

Therefore, in this case, it is shown that the front two wheels are simultaneously in the anti-skid control state. For this reason, at least one of the wheels is locked while the anti-skid control circuit detects the wheel state of the front two wheels. May be configured to start the anti-skid control when is indicated.

In the operation of the solenoid valve device 300 ', similar control is performed for the rear wheels.

When the rotation speed of the wheel is restored, close the solenoid valve NC (see C in Table 1), and then turn the solenoid valve NO if necessary.
If en (see D in Table 1), the hydraulic pressure is transmitted to the pipes 102 and 103, and the brake hydraulic pressure is reprocessed.

In this case, since the hydraulic pressure reduction or the like occurs only in the downstream of the solenoid valve NO, there is substantially no pressure fluctuation on the oil chamber B side, and the influence on the stepping reaction force fluctuation of the brake pedal is minimal.

At the time of fail-safe, when the accumulated pressure is not generated due to the failure of the accumulator 14, the hydraulic pressure is not transmitted to the oil chamber B even when the brake pedal is depressed. The push rod 2 is therefore moved until its shoulder 2d engages the control piston 3, which is directly pressed by the push rod 2.

As a result, a hydraulic pressure is generated in the oil chamber F, and the hydraulic pressure in the oil chamber F is changed to the oil chambers G and G of the two sub cylinder devices 200L and 200R.
Informed to G '. Therefore, in the FtR-RrR system, the oil chambers D and D'of the auxiliary cylinder devices 200L and 200R are provided.
Because the hydraulic pressure cannot be transmitted due to the failure of the accumulator,
Power piston 208, 208 ', hydraulic piston 20
2, 202 'does not move, and the oil pressure in the oil chambers G, G'is transmitted to the oil chambers E, E'through the flow paths 203a, 203a' and is transmitted to the brake device as a fail-safe hydraulic pressure. . In this way, the braking force is generated depending on the operation of the fail-safe hydraulic pressure generating mechanism.

In the present embodiment described above, the brake hydraulic pressure generated / transmitted via the sub-cylinder device and the brake hydraulic pressure directly transmitting the control hydraulic pressure of the hydro booster mechanism are substantially the same in consideration of the braking force balance between the left and right wheels. When it is desired that the brake oil pressure is designed to satisfy the above condition, and there is a possible difference in the speed of the brake hydraulic pressure transmission, it is preferable to provide a throttle valve or the like at any one of them to adjust the transmission flow velocity.

Embodiment 2 In this embodiment shown in FIG. 2, the fail-safe hydraulic pressure generating mechanism is a tandem type, and the hydraulic pressures of these fail-safe oil chambers F and F'are set to two sub-cylinder devices 200L and 2L.
The configuration is the same as that of the first embodiment shown in FIG. 1 except that it is separately connected to 00R.

17 is a second hydraulic piston for a tandem type fill-safe hydraulic pressure generating mechanism, 18 is a return spring, 19
Is cup seal, 20 is competition port, 21
Is an inlet port and 22 is a reservoir. According to such a configuration, there is an advantage that securing the braking force at the time of fail-safe becomes more advantageous than the embodiment. That is,
The action when the accumulator 14 fails is the same as that of the first embodiment, and when FtL or RrR fails, only the defective system is disabled in the case of this example, and the braking force is applied to the other three wheels. Will be secured.

Embodiment 3 In Embodiment 3 shown in FIG. 3, the auxiliary cylinder devices 200FtL, 200RrR, 200FtR,
A case where 200 RrL is provided is shown (note that the sub-cylinder device of this example is divided into a front wheel system and a rear wheel system, and each oil chamber D is made common). Other configurations are practically the same as those of the second embodiment.

In the case of the present embodiment, since the auxiliary cylinder device, which is a mechanism for fail-safe, is compactly integrated and corresponds to one for each of the four wheels, the fail-safety is improved and the auxiliary cylinder device is used. Since it is possible to give a booster ratio, there is an advantage that the main cylinder device can be commonly used for different vehicle types.

〔The invention's effect〕

As described above, the brake hydraulic control system for a vehicle according to the present invention is an unconventional X-piping vehicle by organically combining and combining the respective components for the hydro booster function, the anti-skid function, and the fail-safe function. The preferable brake hydraulic pressure control is realized, and the anti-skid device can be provided at low cost.

[Brief description of drawings]

FIGS. 1 to 3 are schematic views of a partial configuration showing each embodiment of the present invention. 1: Main cylinder device, 2: Push rod 3: Control piston, 4,5: Return spring 7,17: Hydraulic piston 8,18: Return spring 9,19: Cup seal 10,20: Competition port 11, 21 : Intake port 12, 22: Reservoir 13: Reservoir, 14: Accumulator 15: Pump, 16: Check valve 100-105: Hydraulic piping 200: Secondary cylinder device 202: Hydraulic piston, 203: Switching valve 205: Locking rod, 208: Power piston 206, 209: Return spring 300, 300 ': Solenoid valve device

Claims (1)

[Claims] 1. A brake hydraulic pressure control device for use in a brake hydraulic pressure system having a brake hydraulic pressure system of a four-wheel vehicle having two X piping systems, the hydraulic booster mechanism transmitting a control hydraulic pressure depending on a stepping force to a brake pedal. And a main cylinder device incorporating a fail-safe hydraulic pressure generating mechanism for generating at least one fail-safe hydraulic pressure of the two systems,
A brake hydraulic pipe for branching the control hydraulic pressure of the hydro booster mechanism into two directions, one of which is transmitted to each front wheel side braking device of the two systems and the other of which is transmitted to each rear wheel side braking device of the two systems. A sub-cylinder device having a valve device for connecting the fail-safe hydraulic pressure from the fail-safe mechanism to the brake hydraulic pipe of the corresponding system and for transmitting the fail-safe hydraulic pressure to the brake device of the corresponding system when transmission of the control hydraulic pressure fails. For anti-skid control, which is interposed in each of the two branched brake hydraulic pipes that the control hydraulic pressure conveys, receives the anti-skid signal as an input, and reduces or pressurizes the hydraulic pressure on the brake device side, or holds it as necessary. And a brake hydraulic control device for a vehicle.