JPS6331873A - Hydraulic brake for vehicle - Google Patents

Abstract

PURPOSE:To make a brake release state easily maintainable, by constituting a brake to feed the hydraulic pressure stored in an accumulator as pilot pressure, selecting each solenoid valve, at the time of a power source being off, and also feeding a hydraulic fluid to an oil chamber at the brake release side of a brake cylinder. CONSTITUTION:In case of a power source being on, solenoid valves 9, 20 and 22 are selected to the right from the illustrated position, and a part of the hydraulic fluid out of a hydraulic generating circuit 1 is fed to accumulators 12 and 14 for pressure accumulation. And a part of the other is fed to a brake circuit 3, and a part of the fed one is accumulated in an accumulator 21, while a part of the other is fed to an oil chamber 5b at the brake release side of a brake cylinder 5 by way of the solenoid valve 20, making a brake come into a releasing state. On the other hand, at the time of the power source being off, these solenoid valves 9, 20 and 21 are selected to the illustrated position each, and hydraulic pressure inside the accumulator 21 is fed to the solenoid valve 20 as pilot pressure via the solenoid valve 22, making the said valve 20 go to the right, and the hydraulic fluid is fed to the oil chamber 5b, having the brake maintained in the released state.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a hydraulic braking system for a vehicle, and more particularly to a fail-safe type hydraulic braking system that applies the brakes when the power is turned off.

(Prior art) Trolley-type electric locomotives used in coal mines, etc. have traditionally used hydraulic braking devices that operate the brakes when the power is turned off. Based on this, it will be explained below.

The hydraulic circuit includes a hydraulic pressure generation circuit 1, a pressure accumulation circuit 2, a brake circuit 3, a slack adjuster circuit 4, and a brake cylinder 5, and the brake cylinder has an oil chamber 58 on the brake activation side and an oil chamber 5b on the brake release side. The brake is activated by supplying hydraulic oil to the oil chamber 5a, removing the hydraulic oil from the oil chamber 5b and moving the C cylinder rod to the right, and releasing the brake (loosening) by performing the opposite operation. ) to be done.

In the NI+ pressure generation circuit 1, the motor '7 rotates the gear bomb 6 to generate hydraulic pressure, which is maintained at the required pressure by the relief valve 8, and the hydraulic oil is passed through the solenoid valve 9 to the pressure accumulation circuit. 2 and brake circuit 3.

In the pressure accumulating circuit 2, pressure (hydraulic oil) is stored in an accumulator 12 through check valves 10 and 11, so that hydraulic oil can be supplied to the port V5a of the cylinder 5 when the power is turned off.

In the brake circuit 3, the solenoid valve 13 is opened in response to a command from the driver to supply and drain hydraulic oil from the oil chamber 5b of the brake cylinder 5, and in the linear adjuster circuit 4 for maintaining the stroke of the brake cylinder 5. Hydraulic oil is sent from the accumulator 14 to the oil chamber 5a of the brake cylinder 5 to obtain braking force and to maintain a constant distance between the wheels and the braking force. In addition, code 1
6 is a check valve.

Figure 2 shows the state with the oil pressure and power turned off.
When the power is turned on, the gear pump 6 rotates, and as the oil pressure increases, the Ti electromagnetic valve 913 switches, the iron of the brake cylinder 5 moves to the left, and the brake is released. In other words, there is a Fehrleif system that applies the brakes when the power is off.

(The problem that the invention seeks to solve).

Above) If the above hydraulic braking system is applied to vehicles used in coal mines, etc., there are the following disadvantages.

First, in coal mines, etc., there is a dead section for every touch, and when the vehicle passes through this dead section, there is a temporary power outage, so the brakes are applied and hunting occurs in the brake circuit.

Furthermore, when passing through a hopper in a coal mine or the like, the pantograph may be lowered and the vehicle travels by coast, but at this point the power is turned off and the brakes are applied as described above.

In order to eliminate this disadvantage, it would be possible to mount an uninterruptible voltage device such as a storage battery on the vehicle, but there may be a case where there is no space for mounting it, and this would be disadvantageous in terms of cost.

Therefore, the present invention does not use a storage battery or the like, and unless the brake is operated in some way when the power is off,
An object of the present invention is to provide a hydraulic braking device that can maintain a released state.

[Structure of the invention]

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a pressure accumulation circuit that supplies hydraulic oil to an oil chamber on the brake operation side of a brake cylinder;
A hydraulic i+11f7 equipped with a brake circuit having a first electromagnetic valve that supplies hydraulic oil from a hydraulic source to an oil chamber on the brake release side of a brake cylinder when the power is on.
In one device, an accumulator is provided in the brake circuit, and a second solenoid valve is provided that supplies pilot pressure from the accumulator to the first solenoid valve to maintain the C brake release state even if the power is turned off. This is what I did.

(Function) When the power goes from the power on state to the power off state, the second T
i Supply the hydraulic pressure accumulated in the accumulator of the brake circuit from the solenoid valve to the first solenoid valve as pilot pressure,
The first electromagnetic valve is switched, hydraulic oil is supplied to the oil chamber on the brake release side of the brake cylinder, and the brake release state is maintained.

(Example) Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a hydraulic circuit diagram of a hydraulic braking device according to the present invention, and the hydraulic circuit includes a hydraulic pressure generating circuit 1, a pressure accumulating circuit 2, and a pressure accumulating circuit 2.
, a brake circuit 3, a stripe adjuster circuit 4, and a brake cylinder 5. The brake cylinder 5 has an oil chamber 5a on the brake activation side and an oil chamber 5 on the brake release side.
The hydraulic circuit 1 also includes a gear pump 6 that pumps hydraulic oil from a tank, and a gear pump 6 that drives this gear pump 6.
A solenoid valve 9 supplies the pumped hydraulic oil to the pressure accumulator circuit 4 and the brake circuit 3 with the power on, and the pressure of the hydraulic oil supplied to the pressure accumulator circuit 2 and the brake circuit 3 is kept below a certain level. It is equipped with a relief valve 8 for holding.

In addition to the check valves 10 and 11, the pressure accumulation circuit 2 includes an accumulator 12 for accumulating the pressure of hydraulic oil, and the slack adjuster circuit 4 includes a check valve 16 in addition to the accumulator 14.

On the other hand, the brake circuit 3 controls the pressure of the first electromagnetic valve 20, the accumulator 21, and the accumulator 2 to the first
A second solenoid valve 22 is provided to supply the oil to the solenoid valve 20 of the brake cylinder 5, and the oil chamber 5b on the brake release side of the brake cylinder 5 and the first
An emergency valve 23 is connected to the oil path connecting the solenoid valve 20. In addition, the code|symbol 17 is a check valve.

In the above case, when the power is on, the solenoid valve 9°20.2
2 has moved to the right from the state shown in FIG. Therefore, part of the hydraulic fluid from the hydraulic pressure generation circuit 1 is supplied to the pressure accumulation circuit 2 and stored in the accumulators 12 and 14, and the other part is supplied to the brake circuit 3. Then, some of the hydraulic fluid supplied to the brake circuit is transferred to the accumulator 21.
The other part passes through the first electromagnetic valve 20 and is supplied to the oil chamber 5b on the brake release side of the cylinder 5, and the cylinder rond moves to the left and enters the brake release state.

On the other hand, when the power is turned off, the solenoid valve 9゜20.22
is in the state shown in FIG. 1, and the hydraulic oil in the release side oil i5b of the brake cylinder 5 tries to return to the tank, but the hydraulic oil pressure stored in the accumulator 21 via the second solenoid valve 22 The first solenoid valve 20 is supplied as pilot pressure to the first solenoid valve 20, and the first solenoid valve 20 moves further to the right.
Hydraulic oil is supplied to the oil chamber 5b and the brake is maintained in a relaxed state.

If the pressure accumulation in the accumulator 21 is made smaller than the pressure accumulation t1.1 in the accumulator 12.14, the pilot pressure will decrease due to leakage in the N magnetic piece 22 and the pilot pressure circuit, and the power off state will remain for a certain period of time. If this continues, the first solenoid valve 20 is switched, hydraulic oil is supplied from the accumulator 12.14 into the oil chamber 5a, the iron moves to the right, and the brake is applied.

Therefore, for example, when coasting with the pantograph lowered, if the pilot pressure necessary for the coasting time is stored in the accumulator 21, the brakes will not be applied midway.

In addition, when applying the brakes when the power is off, manually operate the emergency valve 23 and release oil. Handle the hydraulic oil in 5b.

〔Effect of the invention〕

As explained above, according to the hydraulic braking device according to the present invention, even when the power is turned off instantaneously, such as when passing through a dead section, the emergency brake is not applied and hunting does not occur in the brake circuit. do not have. Furthermore, since there is no need to provide an uninterruptible voltage device such as a storage battery, it is advantageous in terms of space and cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of a vehicle hydraulic brake 1jJI inlet according to the present invention, and FIG. 2 is a circuit diagram of a conventional hydraulic braking device. DESCRIPTION OF SYMBOLS 1... Hydraulic pressure generation circuit, 2... Pressure accumulation circuit, 3... Brake circuit, 4... Slack adjuster circuit, 5...
...Brake cylinder, 12, 14.21...Accumulator, 20...First solenoid valve, 22...Second
Solenoid valve. Applicant's agent Sato - Foot 1 Figure 2

Claims (1)

[Claims] A pressure accumulation circuit with an accumulator that supplies hydraulic oil from the hydraulic source to the oil chamber on the brake activation side of the brake cylinder, and a pressure accumulation circuit that supplies hydraulic oil from the hydraulic source to the oil chamber on the brake release side of the brake cylinder when the power is on. In the hydraulic braking system, the brake circuit includes an accumulator, and the accumulator supplies pilot pressure to the first electromagnetic valve in a power-off state to perform braking. A hydraulic braking device for a vehicle, comprising: a second solenoid valve that maintains a released state.