JPH0626960B2 - Hydro booster with anti-skidding device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydrobooster for a braking device in which an anti-skidding device is combined.

[Conventional technology]

Conventionally, as a device used for a brake system for vehicle braking, a hydro booster as a booster mechanism, an anti-skid control device for preventing wheel locking during braking, etc. have been proposed variously, but these have been proposed. It is generally configured as an individual device.

However, since these are built into one system called the vehicle brake, if these are combined 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.

From such a viewpoint, for example, a hydro booster with an anti-skidding device as shown in FIG. 2 has been proposed.

This is the main cylinder I, II, II of the cylinder body 1.
A pedal response device 10, a fail-safe hydraulic pressure generation mechanism 30 for the first brake hydraulic system, and a brake hydraulic pressure generation mechanism 40 for the second brake hydraulic system are built in I, of which the fail-safe hydraulic pressure generation mechanism 30 and the second brake hydraulic pressure are included. The brake hydraulic pressure generating mechanism 40 for the system has a configuration similar to that of the tandem type master cylinder device.

The pedal response device in the main cylinder I will be briefly described below. This is a push rod 11 fitted into the small diameter cylinder 1a through one end opening of the cylinder body 1.
And the control piston 12 fitted to the outer peripheral portion of the fitting inner end portion of the push rod 11 and fitted in the large diameter cylinder 1b portion are accommodated, and by the cooperation of the push rod 11 and the control piston 12, According to the stepping force to a brake pedal (not shown) connected to the outer end of the push rod 11, the hydraulic pressure level transmitted from the accumulator 15 which is a pressure accumulating source to the brake hydraulic pressure generating mechanism described later is determined. A pressure control valve is configured.

That is, the control piston 12 has a radial passage 12a for guiding the pressure oil from the accumulator to the inner cylindrical peripheral surface with which the inner end of the push rod 11 is fitted, while the push rod 11 has a control at the inner end. A radial passage 11a that is open to the inner peripheral surface of the piston 12 is provided. Both of these radial passages 11a and 12a 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). When the push rod 11 is moved relative to the control piston 12 by stepping on the brake pedal (during braking), the push rod 11 moves to the facing position, and becomes the communication position of the radial passages 11a and 12a. The pressure oil is transmitted to the radial passage 11a of the push rod 11.

The radial passage of the push rod 11 is adapted to be output downstream through the stepped oil chamber E of the small diameter cylinder portion via the longitudinal passage 11c of the axial center portion, and this stepped oil chamber E '.
Hydraulic action acts in the direction opposite to the push-in of the push rod 11 to apply a stepping reaction force to the brake pedal.

The control piston 12 is biased to the illustrated initial position by a lightly loaded return spring 13 stretched between the control piston 12 and the inner wall of the cylinder body, and the push rod 11
Are pressed outward from the I-th cylinder by the return spring 14.

Further, the push rod 11 and the control piston 12 are
Normally, there is a communication relationship, and there are provided radial passages 11b, 12b for pressure release that release this communication relationship during braking, so that the hydraulic pressure in the stepped oil chamber E'when the brake is not applied or the brake is released. Is released to the reservoir side, which will be described later, through the release oil chamber F.

As described above, the pedal response device 10 housed in the I-th cylinder is operated by the accumulator 15 when the brake is not applied.
The hydraulic oil from the stepped oil chamber E ′ is released to the reservoir 16 via the reservoir oil chamber F, and the pressure release of the stepped oil chamber E ′ is cut off at the time of braking, and the brake is released. The oil pressure corresponding to the degree of stepping on the pedal is transmitted to the stepped oil chamber E '.

Further, the fail-safe hydraulic pressure generating mechanism 30 housed in the main cylinders II and III and the brake hydraulic pressure generating mechanism 40 for the second brake hydraulic system are configured as follows.
That is, it has the 1st I piston 31 which functions substantially as one with the above-mentioned control piston 12, and the 2nd piston 41 arranged in a pair with this, and these oil chamber A and oil chamber B have these 1st and 1st, respectively. When the second pistons 31 and 41 move, they are independent of each other and generate the same hydraulic pressure.

In other words, when the first piston 31 receives an external force and moves in the pressure direction in the figure, the seal 32 closes the competition port 33 to generate a hydraulic pressure in the oil chamber A, and at the same time, the second piston 41 is moved and similarly. Oil pressure is generated in the oil chamber B. In the figure, 34 and 44 are intake ports and 3
Reference numerals 5 and 45 are return springs, and 36 and 46 are reservoirs connected to the respective oil chambers A and B via ports.

Next, the brake oil pressure generating device 60 for the first brake oil pressure system, which is connected to the stepped oil chamber E'and the fail-safe oil chamber A of the pedal response device 10, will be briefly described. This is the sub-cylinder IV of the cylinder body. In the example shown in FIG. 2, the power piston 61 for generating the brake hydraulic pressure at the time of normal braking and the power piston 61 at the time of normal braking cooperate with the power piston 61 to generate the brake hydraulic pressure.
In addition, at the time of a fail, it is composed of a combination of a hydraulic piston 62 having a built-in switching valve 63 for transmitting the hydraulic pressure generated in the fail-safe oil chamber A to the brake device side.

The power piston 61 moves from the stepped oil chamber E ′ by receiving the oil pressure of the control oil chamber C to which the pressure oil is transmitted via the electromagnetic valve device 80 for anti-skidding, which is a combination of electromagnetic valves. A moving force is applied to the piston 62. On the other hand, the hydraulic piston 62 has a passage 62a penetrating in the axial direction, and when it is engaged with the locking rod 64, the ball 63b is normally separated from the valve seat 63a to open the passage 62a. When the piston 62 moves, the engagement by the locking rod 64 is released and the ball 63b moves toward the valve seat 63.
The check valve type switching valve 63 that closes the flow passage 62a by seating in a is incorporated in the flow passage 62a.

The oil chamber A ′ exposed by the power piston tip of the hydraulic piston 62 communicates with the fail-safe oil chamber A, and the oil chamber D exposed by the opposite end of the hydraulic piston 62 is connected to the wheel cylinder W / C of the brake device. It is in communication.

As described above, when the hydraulic pressure is transmitted to the oil chamber C, the power piston 61 moves to press and move the hydraulic piston 62,
As a result, the switching valve 63 is closed, and thereafter, the brake oil pressure proportional to the oil pressure in the control oil chamber C is generated in the oil chamber D.

On the other hand, when the hydraulic pressure is not transmitted to the control oil loss C during braking due to the failure of the accumulator 15 or the like, the hydraulic pressure of the fail-safe oil chamber A is transmitted to the oil chamber A'as described above, and the hydraulic piston 62 moves at this time. Since the switching valve 63 remains open, the oil pressure generated in the fail-safe oil chamber A is transmitted to the oil chamber D via the oil chamber A ', which serves as the brake oil pressure.

The solenoid valve device 80 for anti-skid control controls the oil pressure in the oil chamber C (the oil chamber F and the normally open solenoid valve NO provided in the middle of the path for transmitting the oil pressure from the oil chamber E ′ to the control oil chamber C). Via the normally closed solenoid valve NC to be released to the reservoir 16 and these two solenoid valves NO and NC are selected, for example, from the mode shown in Table 1 below by an anti-skid signal from an anti-skid control circuit (not shown). It's ready.

Such a mode selection is appropriately selected and applied by a known anti-skidding control circuit, which outputs each signal of the brake pressure reduction signal, the holding signal, and the re-pressurization signal according to the rotation state of the wheel. It

By the way, when the operation of the hydro booster with the anti-skidding device as described above is examined in more detail, there is a case where the hydraulic pressure of the control oil chamber C is sufficiently reduced during the anti-skidding control so that the brake hydraulic pressure becomes substantially zero. Considering this, since the power piston 61 returns to the vicinity of the initial stage, a situation similar to the failure of the accumulator during braking is revealed, and the hydraulic pressure of the failsafe oil chamber A may flow into the brake oil chamber D due to the opening of the switching valve 63. Conceivable.

This problem can be avoided by setting the hydraulic pressure generated in the fail-safe oil chamber A to a sufficiently small value during general braking or anti-skidding, but the driver abnormally strongly depresses the brake pedal. In such cases, it may be desirable to further consider the effect.

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above problems, and an object thereof is an anti-skidding device in which an influence from a fail-safe mechanism does not appear during anti-skidding control. It is in the place of providing the attached hydro booster.

[Means for Solving the Problems]

Thus, the feature of the hydrobooster according to the present invention made to realize the above-mentioned object is that the power piston moves depending on the transmission oil pressure level from the pressure accumulation source, and the brake proportional to the moving force of the power piston. A brake hydraulic pressure generating device that generates hydraulic pressure, a pedal response device that determines a transmission hydraulic pressure level from the pressure accumulation source to the brake hydraulic pressure generating device by the operation of a control piston that moves depending on the stepping force of the brake pedal, and this pedal. An electromagnetic valve device for anti-skid control for supplying / discharging the hydraulic pressure transmitted from the responding device to the brake hydraulic pressure generating device based on an anti-skid signal to a pressure reducing / pressurizing or a constant holding condition as necessary, and the pedal responding device. And a fail-safe hydraulic pressure generator that generates a fail-safe hydraulic pressure that depends on the stepping force of the brake pedal. In a hydro booster equipped with a flow path switching means for transmitting the generated fail-safe hydraulic pressure to the downstream brake device side of the brake hydraulic pressure generator when the power piston is not moving, the movement of the control piston of the pedal response device is restricted during anti-skid control. The piston movement restricting means is provided.

〔Example〕

Hereinafter, the present invention will be described based on Examples shown in the drawings.
This example is different from that shown in FIG. 2 in the structure of the pedal response device, except that a fail-safe hydraulic pressure generating mechanism 30 and a brake hydraulic pressure generating mechanism 4 of the second brake hydraulic system are provided.
0, the brake oil pressure generating device 60 having the power piston 61, and the solenoid valve device 80 for anti-skidding control are the same as those in the configuration of FIG. 2, and therefore, the same members are designated by the same reference numerals. , And detailed description thereof is omitted.

A feature of the pedal response device 10 in this example is that the release oil chamber F facing the tip of the control piston 12 is connected to the reservoir 16 via a normally-open hold solenoid valve 18. For this reason, the pressure oil release path from the normally closed solenoid valve NC of the solenoid valve device 80 is the release oil chamber F as shown in FIG.
It is connected to the reservoir 16 'without passing through.

The hold solenoid valve 18 has an input connected to an anti-skid control circuit (not shown) so as to shut off the release oil chamber F and the reservoir 16 from the start of the anti-skid control to the end (release) of the control. Switching operation is performed. Such a switching operation is performed in the existing anti-skidding control circuit, for example, with a signal at the time of detecting an abnormal drop in wheel speed,
It may be performed by appropriately selecting a timer or the like.

According to such a configuration, a predetermined level of hydraulic pressure is transmitted to the stepped oil chamber E'by stepping on the brake pedal, and this is transmitted to the control oil chamber C of the brake hydraulic pressure generating device 60 so that the normal hydraulic pressure is obtained. In addition to the braking operation, during the anti-skidding control, the solenoid oil pressures of the control oil chamber C are increased / decreased by the solenoid valves NO and NC of the solenoid valve device 80. Therefore, the brake oil pressure of the brake fluid chamber D is reduced / pressurized. Alternatively, the holding control is performed, and at this time, the hold solenoid valve 18 blocks the communication with the reservoir 16 of the release oil chamber F as described above. Therefore, even if the brake pedal is stepped on abnormally strongly, this release is performed. Due to the sealing of the oil chamber F, the movement of the control piston 12 and the movement of the first piston 31 to the left in the figure are locked, and a large hydraulic pressure is generated in the fail-safe oil chamber A. Not with.

Therefore, even if the hydraulic pressure in the control oil chamber C becomes a considerably low pressure by the anti-skid control, the problem that the hydraulic pressure in the fail-safe oil chamber A flows into the brake oil chamber D side through the switching valve 63 almost occurs. Therefore, a suitable anti-skidding control is realized.

In this embodiment, the release solenoid chamber F is sealed by the hold solenoid valve 18 to form the piston movement restricting means for restricting the movement of the piston in the pedal response device. However, the present invention is not limited to this. It is not limited, but may be by mechanical means, for example.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention can suitably eliminate the difficulty in providing a preferred fail-safe mechanism in a hydrobooster with an anti-skidding device, and its utility is extremely great.

[Brief description of drawings]

Drawing FIG. 1 is a vertical sectional view of a hydro booster showing an embodiment of the present invention, and FIG. 2 is a vertical sectional view of a hydro booster of the same comparative example. 1 ... Cylinder body 10 ... Pedal response device 11 ... Push rod, 12 ... Control piston 13, 14 ... Return spring 15 ... Accumulator, 16 ... Reservoir 17 ... Pump, 18 ... Hold solenoid valve 30 ... Failsafe hydraulic pressure generating mechanism 31 ... First piston, 32 ... Piston cup 33 ... Competitioning port 34 ... Intake port 35 ... Return spring, 36 ... Reservoir 40 ... Second brake hydraulic system Brake oil pressure generating mechanism 41 ...... Second piston, 42 ...... Piston cup 43 ...... Competing port 44 ...... Intake port 45 ...... Return spring, 46 ...... Reservoir 60 ...... Brake hydraulic pressure generator 61 ...... Power piston , 62 ... hydraulic piston 63 ... switching valve, 4 ...... engagement rod 80 ...... electromagnetic valve device.

Claims (1)

[Claims] 1. A brake hydraulic pressure generating device for generating a brake hydraulic pressure proportional to a moving force of a power piston, in which a power piston moves depending on a transmission hydraulic pressure level from the pressure accumulating source, and a brake hydraulic pressure generating device for the pressure accumulating source. The oil pressure level transmitted to the brake pedal is determined by the operation of the control piston that moves depending on the stepping force of the brake pedal, and the oil pressure transmitted from this pedal oil pressure device to the brake oil pressure generator is converted into an anti-skid signal. Based on this, a solenoid valve device for anti-skid control for supplying / discharging in a depressurized / pressurized state or a fixedly held state as needed, and a fail-safe hydraulic pressure dependent on the stepping force of the brake pedal are generated in cooperation with the pedal response device. The fail-safe oil pressure generator and the generated fail-safe oil pressure are applied to the brake oil when the power piston is not moving. In a hydro booster having a flow path switching means for transmitting to a downstream brake device side of a generator, a piston movement restricting means for restricting a movement of a control piston of the pedal response device at the time of anti-skid control is provided. Hydro booster with device.