JPS6311006Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a brake device that reduces the load on the drive source in a negative brake used for forklifts and the like.

[Conventional technology]

As a conventional negative type brake, for example, there is one shown in Japanese Patent Application Laid-Open No. 56-57562. This type of negative brake generates the braking force by the biasing force of the spring, so when the brake is not applied, the pump must be continuously driven to resist the biasing force of the spring, which consumes battery power. The problem was that there were many.

[Purpose of invention]

This idea was made in view of these conventional problems, and it performs braking operation and release by switching the supply of pressure fluid from a pressure fluid source without using a spring, and also enables braking to be performed when not braking. The purpose of this invention is to solve the above problems by reducing the load on the drive source.

〔Example〕

This invention will be explained below based on FIGS. 1 to 4.

[First example]

A first embodiment is shown in FIGS. 1-3.

1 is a pressure fluid source, 2 is a brake operating mechanism, 3 is a control valve, 4 is an actuator, 5, 6, and 7 are each piping, 8 is a master cylinder, 9 is piping, 10 is a brake unit, 11 is a pump, 12 is a drive source such as an engine or an electric motor; 13 is a reservoir; 14 is a brake pedal;
5 is a spring, 16 is a link, 17 is a piston, 18 is a first pressure chamber, 19 is a second pressure chamber, 20
is the piston rod, 21 is the push rod, 22
is a relief valve, and the above configuration is not substantially different from a conventional brake device.

26 is a switching valve (discharge valve), and a pipe 5 connects the pressure fluid generation source 1 and the control valve 3.
This is a 3-port, 2-position switching solenoid valve that is installed in the pump 11 and switches the flow of the pressure fluid sent out from the pump 11 between the control valve 3 and the reservoir 13.
A switch 23 is a first detection means, and when the brake pedal 14 is depressed, a contact 23a is pressed and outputs a first brake release signal, thereby detecting that the brake operating mechanism 2 is in an activated brake release state. Further, 24 is a switch serving as a second detection means, which detects the brake release state in which the actuator 4 has returned, that is, the piston 17 is at the right end in the figure.
A second brake release signal is output. For this purpose, a cam 20a is formed on the piston rod 20, and a contact 24a comes into contact with the cam 20a for ON operation. The solenoid portion 26a of the switching valve 26 is connected in series with the switch 23, the switch 24, and the power source 25.

It should be noted that even if the switching valve 26 is provided between the control valve 3 and the actuator 4, this invention will function in the same manner.

Next, the effect will be explained.

In the braking state, as shown in FIG. 1, the brake pedal 14 is in an inactive, brake-released state;
The control valve 3 is in the A position, the working fluid from the pressure fluid source 1 is introduced into the first pressure chamber 18 of the actuator 4, the piston rod 20 is in the braking operation state, and the push rod 21 of the master cylinder 8 is pressed and brakes. unit 10
is operating the brake. At this time, switch 2
Both valves 3 and 24 are OFF, and the switching valve 26
is not energized. Therefore, the maximum pressure of the working fluid in the circuit from the pressure fluid source 1 to the first pressure chamber 18 of the actuator 4 is regulated to the relief pressure by the action of the relief valve 22, thereby ensuring that the braking state of the brake unit 10 is maintained. do.

In the non-braking state, when the brake pedal 14 is depressed, the switch 23 turns on and outputs the first brake release signal, and the control valve 3 becomes the B position (see Fig. 2), and the pressure fluid generation source 1
The working fluid from is introduced into the second pressure chamber 19 of the actuator 4, and the piston 17 is introduced into the first pressure chamber 1.
While returning the working fluid of No. 8 to the reservoir 13, the switch 24 is turned ON to output the second brake release signal, and the push rod 21 of the master cylinder is returned to the brake release direction to disable the brake unit 10. state. When the switches 23 and 24 are both turned ON and output the first brake release signal and the second brake release signal, the solenoid section 26a of the switching valve is energized by the power supply 25, and the switching valve 26 is activated as shown in FIG. When the pump 11 is operated to the D position, the working fluid from the pump 11 is drained into the reservoir 13 without being introduced into the second pressure chamber 19.

When the driver's foot leaves the brake pedal 14, the switch 23 is turned OFF, so the switching valve 26 de-energizes the solenoid section 26a and switches to C.
At the same time, the control valve 3 becomes the A position, and a braking state can be quickly obtained.

The braking action when the vehicle is stopped (ignition OFF) is performed by a parking brake mechanism (not shown).

[Second example]

FIG. 4 shows a second embodiment.

The switch 23, which is a first detection means, detects that the brake operation mechanism 2 is in an activated brake release state and outputs a first brake release signal, and detects that the actuator 4 is in a restored brake release state and outputs a second brake release signal. The arrangement of the switch 24, which is the second detection means for outputting the brake release signal, and the power supply 25 are the same as in the first embodiment. An electromagnetic relay 27 having a contact that opens when the solenoid section 27a is energized is provided in series with the switches 23 and 24.
The drive source 12 is turned off by the OFF operation.

When the brake is not applied, the brake pedal 14 is depressed and the switch 23 is turned on, and the piston 17 of the actuator is fully returned and the switch 24 is turned on.
When activated, a first brake release signal and a second brake release signal are obtained, and the electromagnetic relay 27 is activated OFF. If the drive source 12 is an electric motor, the switch 23 is turned OFF when the brake pedal 14 is released.
When actuated, the electric motor is re-driven into a braking state.

[Structure of the idea]

As explained above, according to this invention, the configuration includes a pressure fluid generation source, a control valve that switches the flow of pressure fluid from the pressure fluid generation source in response to a brake operation mechanism, and an actuator that operates reciprocally by introducing pressure fluid into the first pressure chamber or the second pressure chamber, piping that communicates these, a master cylinder that operates the braking operation by inputting the braking operation of the actuator, and the master cylinder and the piping. In the brake device, the brake device has a brake unit connected to the brake unit, and releases the brake of the brake unit by actuation of the brake operation mechanism, wherein the brake operation mechanism detects that the brake is in a brake release state, and releases a first brake release. a first detection means for outputting a signal, a second detection means for detecting that the actuator is in a brake release state and outputting a second brake release signal, and releasing a circuit between the pressure fluid generation source and the actuator. Provided with a discharge valve that operates to drain the working fluid or an electromagnetic relay that operates to stop the drive of the pressure fluid generation source,
The brake device operates the discharge valve or the electromagnetic relay when both the first brake release signal and the second brake release signal are input.

[Effect of idea]

Therefore, when there is no need to supply working fluid to the actuator, the pressure fluid generated in the pressure fluid generation source is drained into the reservoir or the drive source is stopped, which saves unnecessary load on the drive source. This has the advantage of saving energy, improving the durability of the drive source, and, when using an electric motor as the drive source, avoiding overheating of the electric motor.

[Brief explanation of the drawing]

Fig. 1 is a conceptual layout diagram of a brake device according to a first embodiment of this invention, Figs. 2 and 3 are respectively explanatory diagrams of the operation of the brake equipment, and Fig. 4 is a diagram showing a second embodiment of this invention. FIG. 2 is a conceptual layout diagram of such a brake device. DESCRIPTION OF SYMBOLS 1... Pressure fluid generation source, 2... Brake operation mechanism, 3... Control valve, 4... Actuator, 5, 6, 7, 9... Piping, 8... Master cylinder, 18... First pressure chamber , 19... second pressure chamber, 23... switch (first detection means), 2
4... switch (second detection means), 26... switching valve (discharge valve), 27... electromagnetic relay.

Claims (1)

[Scope of utility model registration request] A pressure fluid generation source, a control valve that switches the flow of pressure fluid from the pressure fluid generation source in response to a brake operation mechanism, and a control valve that introduces the pressure fluid from the control valve into the first pressure chamber or the second pressure chamber. The brake operating mechanism includes an actuator that reciprocates with the actuator, piping that communicates these, a master cylinder that inputs the braking action of the actuator to perform the braking action, and a brake unit that is connected to the master cylinder through the piping. A brake device that releases the brake of a brake unit upon activation of the brake unit includes a first detection means for detecting that the brake operating mechanism is in a brake release state and outputting a first brake release signal, and an actuator for detecting that the brake operation mechanism is in a brake release state. a second detection means that detects that the brake is present and outputs a second brake release signal, and drives a discharge valve or a pressure fluid generation source that releases the circuit between the pressure fluid generation source and the actuator to drain the working fluid. A brake device comprising: an electromagnetic relay that operates to stop the discharge valve or the electromagnetic relay, and operates the discharge valve or the electromagnetic relay when both the first brake release signal and the second brake release signal are input.