JPH0624909B2 - Hydro booster with anti-skidding device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a hydro booster for a brake device in which an anti-skid device is combined.

[Conventional technology]

Conventionally, as a device used for a brake system for vehicle braking, various proposals have been made such as a hydro booster as a booster mechanism, an anti-skid control device for preventing a vehicle transport lock from occurring during braking, and a fail-safe mechanism. But
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.

And, as one of such functional improvements, it is generally desirable to take measures so that the brake hydraulic system is multiplexed so that loss of the braking force does not occur even if one system fails.

[Problems to be Solved by the Invention]

The present invention has been made from such a viewpoint, and an object thereof is to provide a hydrobooster in which an antiskid device is preferably combined.

Another object of the present invention is to provide a hydro booster in which booster system pressurization systems are provided in duplicate and the safety of the brake device is improved during normal braking.

Still another object of the present invention is to provide a device that allows the structure of the hydrobooster to be made common to various vehicles as much as possible.

[Means for Solving the Problems]

Therefore, the feature of the hydro booster according to the present invention, which is made to realize such an object, is that the pedal that determines the transmission hydraulic pressure level from the pressure accumulation source to the first control oil chamber depending on the stepping force to the brake pedal. A response device, a first solenoid valve device that controls the supply and discharge or holding of the hydraulic pressure in the first control oil chamber by inputting an anti-skid signal, and a second control that generates a hydraulic pressure that depends on the stepping force of the brake pedal. A main cylinder device for transmitting the generated oil pressure to the oil chamber, a second solenoid valve device for interrupting the oil pressure transmission from the main cylinder device to the second control oil chamber by inputting an anti-skid signal, and one end of the second control oil chamber The small-diameter piston portion facing the brake oil chamber and the other end facing the brake oil chamber, and the large-diameter piston portion facing one end to the first control oil chamber, and moved by receiving the hydraulic action of the first and second control oil chambers. Power Pis Includes a secondary cylinder device down is housed, is the brake oil chamber of the auxiliary cylinder device where forming a structure connected to the brake device.

〔Example〕

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

In this example, the pedal response device 1 and the tandem master cylinder type main cylinder device 10 are combined and built into the cylinder body 100, and the auxiliary cylinder device 30 for generating the boosted brake hydraulic pressure is integrated. This may include the auxiliary cylinder device as a separate body.

First, the structure of the pedal stress device 1 will be described. The pedal stress device 1 includes a bush rod 2 inserted into the small-diameter cylinder portion 101 from an opening (right end in the drawing) of a cylinder body 100, and the insertion inner end of the push rod 2. The control piston 3 fitted in a large-diameter cylinder portion 102 provided in the cylinder body 100 has an axial center cylinder hole into which the outer peripheral portion of the portion is fitted in a liquid-tight manner, and these are accommodated. By the cooperation of the push rod 2 and the control piston 3,
In accordance with a stepping force applied to a brake pedal (not shown) connected to the outer end portion of the push rod 2, the accumulator 4 serving as a pressure accumulator causes the first sub-cylinder device 30 to be described later.
The pressure control valve is configured to determine the hydraulic pressure level transmitted to the control oil chamber C.

That is, the control piston 3 has a radial passage 3a that guides the pressure oil from the accumulator 4 to the axial center cylinder hole (inner cylinder peripheral surface) with which the inner circumference of the push rod 2 fits,
On the other hand, the push rod 2 is provided with a passage 2a in the generatrix direction which is open to the inner peripheral surface of the control piston 3 on the outer peripheral surface of the inner end portion, and both of these passages 2a and 3a are in a normal state (when not braking). Is in a non-communicating state where they do not face each other as shown in the drawing, but when the bush rod 2 moves relative to the control piston 3 (moves leftward in the drawing) due to the depression of the brake pedal (during braking), the bush rod 2 becomes the facing position. The passages 2a and 3a are in communication with each other, and the hydraulic pressure from the accumulator 4 is transmitted to the passage 2a of the push rod 2 in the generatrix direction.

The hydraulic pressure transmitted to the generatrix passage 2a of the push rod 2 is introduced into the oil chamber E of the stepped portion of the small diameter cylinder portion 101 and the large diameter cylinder portion 102 through the diagonal passage 3b of the control piston 3, and It is output to the downstream system which will be described later through this oil chamber E.

The control piston 3 is biased to the initial position shown by a lightly loaded return spring 5 stretched between the control piston 3 and a fixed portion of the cylinder body 100, and the push rod 2 is provided by a return spring of a brake pedal (not shown). Due to this, the spring force for escaping from the small diameter cylinder portion 10 to the outside (to the right in the drawing) is urged. 6 is
It is a locking ring that defines the limit of the control piston 3 coming out through the plug 70.

The tip of the control piston 3 is operatively linked to the first piston 11 of the main cylinder device 10 described later, and the peripheral surface on the tip side faces the open oil chamber G communicating with the reservoir 60. There is.

In addition, the generatrix passage 2a of the push rod 2 passes through the fitting portion between the control piston 3 and the push rod 2, the radial passages 2b and 2c of the push rod 2, and the axial passage 2d.
When the vehicle is not braked, it communicates with the release oil chamber G, whereby the oil pressure in the oil chamber E is released when the vehicle is not braked.

As described above, in the pedal response device housed in the cylinder, the transmission of the hydraulic pressure from the accumulator 4 to the oil chamber E is interrupted when the brake is not applied, and the hydraulic pressure in the oil chamber E is the same as that of the push rod 2 described above. It is released through the passageway 2d. On the other hand, at the time of braking, the pressure release of the oil chamber E via the axial passage 2d and the like is cut off, and the hydraulic pressure corresponding to the step on the brake pedal is transmitted from the accumulator 4 to the oil chamber E. become.

The oil chamber E is connected to the first control oil chamber C of the sub cylinder device 30 via the first solenoid valve device 40.

Next, a tandem master cylinder type main cylinder device 10
The main cylinder device 10 of this example will be described.
Is a first piston 11 that functions substantially as one body with the control piston 3 described above, and a second piston arranged in a pair with the first piston 11.
The piston 12 is provided, and when the first and second pistons 11 and 12 are moved, the oil chamber F of the oil chamber D produces independent and equal hydraulic pressures.

The main cylinder device 10 including the first piston 11 and the second piston 12 is structurally similar to a general tandem master cylinder. That is, when the first piston 11 receives an external force and moves to the left in the figure, the seal 13
Closes the competition port 15 to generate oil pressure in the oil chamber D, and at the same time, the second piston 12 is moved to similarly generate oil pressure in the oil chamber F. In the figure, 1
Reference numerals 7 and 18 are intake ports, reference numerals 19 and 20 are return springs, and reference numerals 21 and 22 are reservoirs connected to the respective oil chambers D and F via the respective ports.

The oil chamber D is connected to the second control oil chamber B of the sub-cylinder device 30, and in the middle of this connection path, the second normally open type closed by receiving the anti-skid signal (pressure reduction signal) as an input. The electromagnetic valve device 50 is installed.

The oil chamber F is an oil chamber for a separate brake hydraulic system, and can be directly transmitted to the brake device as a brake hydraulic pressure, or a sub cylinder device is separately provided for the same system and connected to the second control oil chamber. You may

Next, the sub cylinder device 30 will be described.

In the sub-cylinder device 30 of this example, one end of the small-diameter piston portion 31 of the power piston 51 faces the brake fluid chamber A communicating with the wheel cylinder W / C of the brake device, and the other end of the small-diameter piston portion 31 is the first end. It is provided so as to face the second control oil chamber B.

A power cylinder 33 is provided that is pressure-divided with respect to the sub-cylinder 32 accommodating the small-diameter piston portion 31, and the large-diameter portion of the power cylinder 33 faces the first control oil chamber C. Also, a large-diameter piston portion 35, whose small-diameter portion passes through the through hole 34 and the second control oil chamber B and is integrally formed with the small-diameter piston portion 31, is accommodated, and the small-diameter piston portion 31 and the large-diameter piston are accommodated. The portion 35 constitutes the power piston 51. 36,
37 are return springs, respectively.

Further, the small-diameter piston portion 31 is provided with a flow path 31a connecting between the second control oil chamber B and the brake oil chamber A, and due to the pressure difference between the second control oil chamber B and the brake oil chamber A, An on-off valve 38 for opening and closing the flow path 31a is built in.

In the sub-cylinder device 30 having the above configuration, the power piston 51 acts on the small-diameter piston portion 31 by the hydraulic pressure of the second control oil chamber B and the large-diameter piston portion 35 of the first control oil chamber C. Due to the action of the hydraulic pressure, the brake fluid is moved in a direction in which the internal volume of the brake fluid chamber A is reduced, and the brake hydraulic pressure is generated according to the movement.

The brake oil pressure obtained in the brake oil chamber A is the cross-sectional area of the first piston 11 of the main cylinder device 10,
The amplification ratio is determined according to the ratio of the cross-sectional area of the small-diameter piston portion 31 and the cross-sectional area of the large-diameter portion and the small-diameter portion of the large-diameter piston portion 35. By exchanging 30 of various sizes, it is easy to select an amplification ratio that suits different vehicles.

Next, the anti-skid control will be described. The anti-skid control of this example is performed by the first solenoid valve device 40 and the second solenoid valve device 50.

The first solenoid valve device 40 in the present example is arranged from the oil chamber E to the first
Normally-open solenoid valve 41 provided in the middle of the path for transmitting the oil pressure to the control oil chamber C, and a normally-closed solenoid valve for releasing the oil pressure in the oil chamber C to the reservoir 60 (via the oil chamber G). These two solenoid valves 41 and 42 are configured so that the mode shown in Table 1 below can be selected by an anti-skid signal from an anti-skid control circuit (not shown).

For such mode selection, a known anti-skid control circuit may output a brake pressure reduction signal, a holding signal, and a re-pressurization signal in accordance with the rotation state of the wheel.

Reference numeral 43 is a pump that pumps pressure oil from the release system (oil chamber G) to the accumulator 4.

Further, the second solenoid valve device 50 shuts off the communication between the oil chamber D and the second control oil chamber B from the start time of the anti-skid control to the end (release) of the anti-skid control. This is because the brake hydraulic pressure on the side of the brake device is appropriately controlled according to the anti-skid control circuit even if the brake pedal is stepped down more strongly during the anti-skid control. Further, by shutting off the second electromagnetic valve device 50 as described above, the oil chamber D is brought into a sealed state, so that there is an advantage that further stepping of the brake pedal is restrained.

Since the anti-skid control generally ends the operation of the second solenoid valve device 50 in a relatively short time, the operation may be released by using a timer.

The operation of the hydrobooster with an anti-skid device having the above configuration will be summarized and described.

During normal braking By pressing the push rod 2 from the brake pedal,
The pedal response device 1 functions to transmit hydraulic pressure to the oil chamber E,
Further, a reaction force is generated on the push rod 2 while stepping on it. It should be noted that this stepping reaction force is derived from the hydraulic force that the first piston 11 receives from the oil chamber D.

The oil pressures in the oil chamber E and the oil chamber D are transmitted to the first and second control oil chambers B and C of the sub-cylinder device 30, respectively, and the brake oil pressure is generated in the brake oil chamber A at a predetermined amplification ratio. .

During anti-skid control If a sudden drop in wheel rotation occurs during the brake operation,
First, the solenoid valve 41 is activated by an anti-skid signal (not shown).
The second solenoid valve range 50 is closed as well. Then, further increase of the hydraulic pressure in the oil chamber A is stopped, and at the same time, the solenoid valve 42 is opened. Therefore, the hydraulic acting force of the first control oil chamber C on the large-diameter piston portion 35 is reduced and the brake hydraulic pressure is reduced. , The braking force of the wheels becomes smaller (see B in Table 1).

If the wheel rotation speed is recovered by this, the solenoid valve 42
Is closed (see C in Table 1), and then the solenoid valve 41 is opened as needed (see D in Table 1), the hydraulic pressure is transmitted to the first control oil chamber C, and the brake hydraulic pressure (oil chamber A). ) Is repressurized. The power piston 5 for this repressurization
When 1 is moved, oil is supplied from the oil chamber H to the oil chamber B by the lip deformation of the piston cup 80.

〔The invention's effect〕

According to the present invention, by integrating the anti-skid device and the hydro booster, it is possible to reduce the size of various devices used for the brake system, and the following effects can be obtained, and their dedicatedness is extremely high. Is large.

(1) The safety is high because there are two normal pressure passages.

(2) Since the boosting ratio can be changed by the sub cylinder device, the main cylinder device can be used in a wide range.

(3) The pedal stroke does not change during power failure.

(4) When the circuit from the second solenoid valve device 50 to the brake fails, the second solenoid valve device 50 can be closed so as not to affect other circuits.

[Brief description of drawings]

The drawing is a sectional view of a schematic example of a hydrobooster according to the present invention. 1 ... Pedal response device, 2 ... Push rod, 3 ... Control piston, 4 ... Accumulator, 5 ... Return spring, 6 ... Locking ring, 10 ... Main cylinder device, 11 ... First piston, 12 ... No. 2 Piston 13,14 ... Piston cup 15,16 ... Competing port 17,18 ... Intake port 19,20 ... Return spring 21,22 ... Reservoir 30 ... Sub cylinder unit 31 ... Small diameter piston part , 32 ... Sub-cylinder 33 ... Power cylinder, 34 ... Through hole 35 ... Large-diameter piston part 36, 37 ... Return spring 38 ... Open / close valve 40 ... First solenoid valve device 41, 42 ... Solenoid valve 43 ... Pump 50 ... Second solenoid valve device 51 ... Power piston

Claims (2)

[Claims] Claim: What is claimed is: 1. A pedal response device for determining a hydraulic pressure level transmitted from a pressure accumulating source to a first control oil chamber depending on a stepping force applied to a brake pedal.
First solenoid valve device for controlling the supply and discharge or holding of the hydraulic pressure in the control oil chamber, the main cylinder device that generates the hydraulic pressure depending on the stepping force of the brake pedal, and transmits the generated hydraulic pressure to the second control oil chamber, A second solenoid valve device that cuts off hydraulic pressure transmission from the main cylinder device to the second control oil chamber by inputting a skid signal, a small diameter with one end facing the second control oil chamber and the other end facing the brake oil chamber. The piston portion and one end are the first
And a large-diameter piston portion facing the control oil chamber of
An anti-skid device is provided, comprising a sub-cylinder device accommodating a power piston that moves under the hydraulic action of a second control oil chamber, and the brake oil chamber of the sub-cylinder device is connected to the brake device. Hydro booster. 2. A ratio of the cross-sectional area of the small-diameter piston portion of the power piston facing the brake oil chamber to the cross-sectional area of the large-diameter piston portion facing the first control oil chamber is set to an amplification factor of 1 or more. A hydro booster with an anti-skid device as set forth in claim (1).