JPH0433178Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a brake control device, and more particularly, to a device that directly operates the brake using the hydraulic pressure of a master cylinder when a hydraulic pressure source for brake operation fails.

(Prior Art) In general, a vehicle brake control device applies hydraulic pressure from a master cylinder to a hydraulic booster when the brake pedal is depressed, and when the hydraulic booster operates, the hydraulic pressure is increased from a hydraulic source. There are devices in use that supply pressure to the brakes to accurately brake the vehicle.

As a conventional brake control device of this type, one shown in FIG. 2, for example, is known.

In FIG. 2, reference numeral 1 denotes a hydraulic booster, and a pair of pistons 4 and a piston 4 provided in the hydraulic booster 1 receive the hydraulic pressure of a master cylinder 3 generated when the brake pedal 2 is depressed.
A pair of spool valves 5 provided in the piston 4 and in contact with the piston 4 move to the left in the figure. As the spool valve 5 moves, hydraulic pressure from the hydraulic power source 6 is applied to the brakes 8 of the pair of front wheels 7 through the spool valve 5 shown in the upper part of the figure, and to the brakes 9 of the pair of rear wheels 10 through the spool valve 5 shown in the lower part of the figure. are respectively supplied to brake the vehicle.

(Problems to be solved by the invention) However, in such conventional brake control devices, the brakes are operated only by the hydraulic pressure supplied from the hydraulic source, so for example, due to a malfunction, etc. When the hydraulic power source fails, the brakes cannot be activated, which poses a problem in that the vehicle is unsafe to drive.

(Purpose of the invention) Therefore, the present invention provides a hydraulic booster with a spool valve that opens and closes the hydraulic pressure of the hydraulic source and a switching piston with a passage hole.
The switching piston supplies hydraulic pressure from the hydraulic power source to the brakes through the passage hole, and when the hydraulic power source fails, the switching piston releases the hydraulic pressure in the master cylinder and supplies it to the brakes. The purpose of this system is to operate all brakes accurately to ensure safe vehicle operation.

(Means for Solving the Problems) In order to achieve the above object, the brake control device according to the present invention includes a hydraulic booster between the master cylinder and the brake, and the hydraulic booster is actuated by the hydraulic pressure of the master cylinder. a spool valve that opens and closes the hydraulic pressure of the hydraulic source; a spool valve that supplies the hydraulic pressure of the hydraulic source and a master cylinder that opens and closes the hydraulic pressure; A brake control device is provided with a switching piston, wherein when the hydraulic power source is in normal operation, the switching piston closes off hydraulic pressure from the master cylinder and allows hydraulic pressure from the hydraulic power source supplied from the spool valve to pass through. The hydraulic pressure is supplied to the brakes through the hole, and when the hydraulic power source fails, the switching piston releases hydraulic pressure from the master cylinder and supplies it to the brakes, so that all brakes will operate even if the hydraulic power source fails.

(Function) In the present invention, the hydraulic booster is equipped with a spool valve that opens and closes the hydraulic pressure of the hydraulic power source, and a switching piston with a through hole.When the hydraulic power source is in normal operation, the switching piston passes the hydraulic pressure through the through hole. Hydraulic pressure from the source is supplied to the brake, and when the hydraulic power source fails, the hydraulic pressure in the master cylinder is released by the switching piston and is supplied to the brake. Furthermore, even when the hydraulic power source fails, all the brakes are operated accurately, ensuring safety in driving the vehicle.

(Example) Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention.

In FIG. 1, 20 is a hydraulic booster;
In the housing 21 of the hydraulic booster 20, a pair of cylinder chambers 22, a valve body chamber 23, and a switching cylinder chamber 24, which communicate with each other, are sequentially formed from the right side in the figure. 23 and the switching cylinder chamber 24 are arranged parallel to each other. A pair of pistons 25, a spool valve 26, and a switching piston 27 are slidably fitted into each pair of cylinder chambers 22, valve body chamber 23, and switching cylinder chamber 24, respectively.

The piston 25 contacts the right end surface of the spool valve 26 via the front end surface of the plunger portion 25a, and is urged rightward in the figure by a spring 28 provided within the cylinder chamber 22. Then, by depressing the brake pedal 29, the master cylinder 3
0 operates, and the hydraulic pressure of the master cylinder 30 is passed through the supply port 31 to the piston 25 through a pair of supply ports 31 formed in the housing 21 and communicating with each cylinder chamber 22.
When applied to the piston 25, the spring 28
It overcomes the urging force and moves to the left in the figure. On the other hand, since the right end surface of the spool valve 26 is in contact with the plunger portion 25a of the piston 25, the spool valve 26 is moved into the valve body chamber 25 by the movement of the piston 25.
The spool valve 26 is moved to the left by overcoming the biasing force of a spring 32 provided therein that biases the spool valve 26 to the right. Along with this, the spool valve 26 has through holes 33, 3 formed in the spool valve 26 and communicating with each other.
4, a pair of supply ports 35 formed in the housing 21 and a pair of through holes 36 that communicate the valve body chamber 23 and the switching piston chamber 24 are communicated with each other. The hydraulic pressure from the supplied hydraulic power source 37 is switched to the cylinder chamber 2.
4. That is, the spool valve 26 provided in the hydraulic booster 20 is connected to the master cylinder 30.
It has a function of opening and closing the hydraulic pressure of the hydraulic power source 37 by operating with the hydraulic pressure of the hydraulic pressure source 37.

Here, the hydraulic source 37 includes a hydraulic pump 41 that sucks hydraulic oil from an oil tank 38 through a strainer 39 and supplies hydraulic pressure to the hydraulic booster 20 through a check valve 40, an electric motor 42 that drives the hydraulic pump 41, The main elements include a relief valve 43 provided downstream of the check valve 40 to adjust the hydraulic pressure, a pair of pressure switches 44, and an accumulator 45 provided downstream of the pressure switch 44.

The switching piston 27 is biased toward the left in the figure by a spring 46 provided in the switching cylinder chamber 24, so that the tip end 27a of the switching piston 27
A pair of supply ports 47 formed in the housing 21 and supplying the hydraulic pressure of the master cylinder 30 to the switching cylinder chamber 24 are closed. Further, the passage holes 48 formed in each switching piston 27 allow hydraulic oil from the hydraulic power source 37 supplied from the valve body chamber 23 to pass through the through hole 36, and are formed in the housing 21 and pass through the hydraulic oil from the hydraulic power source 37, which is supplied from the valve body chamber 23. A pair of front wheels 5 through a pair of communicating load ports 49
0 brakes 51 and a pair of rear wheels 52
Hydraulic oil is supplied to each of the brakes 53. That is, the hydraulic booster 20 is connected to the master cylinder 30.
A switching piston 27 provided between the brakes 51, 53 and the hydraulic booster 20 is supplied with hydraulic pressure from a hydraulic source 37 from a spool valve 26, and is also supplied with hydraulic pressure from a master cylinder 30. The switching piston 27 has the function of opening and closing hydraulic pressure into the switching cylinder chamber 24. Further, the switching piston 27 is provided with a passage hole 48 that supplies the hydraulic pressure of the hydraulic source 37 supplied from the spool valve 26 to the brakes 51 and 53 when the hydraulic source 37 is in normal operation. Note that 54 is a pair of drain ports that are formed in the housing 21 and discharge the drain from each valve body chamber 23, respectively.

Next, the effect will be explained.

When braking the vehicle, the master cylinder 30 is activated by depressing the brake pedal 29, and the hydraulic pressure of the master cylinder 30 is applied to the piston 25 through the supply port 31, causing the piston 25 to overcome the biasing force of the spring 28. Move to the center left. Along with this, the spool valve 26 also moves in the same direction to overcome the biasing force of the spring 32, and the supply port 35 and the through holes 33 and 34 communicate with each other, and the hydraulic power source 37 applied to the supply port 35 is activated. Hydraulic pressure is applied into switching cylinder chamber 24 through supply port 35, through holes 33, 34 and through hole 36. At this time, the hydraulic pressure applied in the switching cylinder chamber 24 assists the biasing force of the switching piston 27 in the left direction in the figure, and the tip end 27a of the switching piston 27 is assisted.
closes the supply port 47 to which the hydraulic pressure of the master cylinder 30 is applied. Therefore, the hydraulic pressure of the hydraulic source 37 applied within the switching cylinder chamber 24 is applied to the passage hole 48 of the switching piston 27 and the load port 4.
9 through brake 51 and brake 53, respectively.
is added to brake the vehicle.

That is, when the hydraulic power source 37 is operating normally, the switching piston 27 closes off the hydraulic pressure from the master cylinder 30, and at the same time supplies the hydraulic pressure of the hydraulic power source 37 supplied from the spool valve 26 to the brakes 51, 53 through the passage hole 48. do.

On the other hand, due to a cause such as a failure, the hydraulic power source 37
has failed, and the hydraulic pressure of the hydraulic power source 37 is reduced to the hydraulic booster 20.
When the switching piston 27 is not supplied to the left side, only the biasing force of the spring 46 is applied without assisting the switching piston 27. Therefore, the hydraulic pressure in the master cylinder 30 generated by depressing the brake pedal 29 passes through the supply port 47 to switch The force is applied to the tip end 27a of the piston 27, and the switching piston 27 overcomes the biasing force of the spring 46 and moves to the right, closing the through hole 36 and causing the hydraulic pressure of the master cylinder 30 to flow into the switching cylinder chamber 24. It will be released. Then, from the switching cylinder chamber 24 to the load port 49
The hydraulic pressure of the master cylinder 30 is applied to the brakes 51 and 53, respectively, to brake the vehicle.

That is, when the hydraulic power source 37 fails, the switching piston 27 releases the hydraulic pressure from the master cylinder 30 and supplies it to the brakes 51, 53, and even when the hydraulic power source 37 fails, all the brakes 51, 53 operate. The vehicle is braked.

As described above, in this embodiment, the hydraulic pressure booster 20 includes a spool valve 26 for opening and closing the hydraulic pressure of the hydraulic power source 37 and a switching piston 2 in which the passage hole 48 is drilled.
7 is provided, and when the hydraulic source 37 is in normal operation, the switching piston 27 closes the hydraulic pressure of the master cylinder 30, supplies the hydraulic pressure of the hydraulic source 37 to the brakes 51 and 53 through the passage hole 48, and operates the brakes 51 and 53. Operate. On the other hand, when the hydraulic power source 37 fails, the switching piston 27 releases the hydraulic pressure in the master cylinder 30 and supplies it to the brakes 51 and 53.
1,53 is activated. Therefore, even when the hydraulic power source 37 fails, all the brakes 51, 53 of the front wheel 50 and rear wheel 52 can be operated accurately, so that safety in driving the vehicle can be ensured.

(Effects) According to the present invention, the hydraulic booster is provided with a spool valve that opens and closes the hydraulic pressure of the hydraulic power source, and a switching piston with a passage hole, so that when the hydraulic power source is in normal operation, the switching piston passes through the passage hole. The hydraulic pressure from the hydraulic power source is supplied to the brakes, and if the hydraulic power source fails, the switching piston releases the master cylinder's hydraulic pressure and supplies it to the brakes, so even if the hydraulic power source fails, all brakes can be applied accurately. can operate. Therefore, safety in driving the vehicle can be ensured.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing an embodiment of a brake control device according to the present invention, and FIG. 2 is an overall configuration diagram showing a conventional brake control device. 20... Hydraulic pressure booster, 26... Spool valve,
27...Switching piston, 30...Master cylinder, 37...Hydraulic pressure source, 48...Passing hole, 51,5
3...Brake.

Claims (1)

[Scope of utility model registration request] A hydraulic booster is provided between the master cylinder and the brake, and the hydraulic booster includes a spool valve that is operated by the master cylinder's hydraulic pressure to open and close the hydraulic pressure of the hydraulic source, and a spool valve that receives the hydraulic pressure of the hydraulic source. The brake control device is provided with a switching piston, which is supplied with hydraulic pressure from a master cylinder and opens and closes the hydraulic pressure, and has a passage hole formed therein, and when the hydraulic pressure source is normally operated. , the switching piston closes the hydraulic pressure from the master cylinder and supplies the hydraulic pressure from the hydraulic source supplied from the spool valve to the brake through the passage hole, and when the hydraulic power source fails, the switching piston closes the hydraulic pressure from the master cylinder. A brake control device characterized in that the hydraulic pressure is released and supplied to the brakes so that all the brakes are operated even in the event of a failure of the hydraulic power source.