JPH0529260Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a brake device for parking a revolving body of an upper swing type construction machine.

BACKGROUND OF THE INVENTION Some upper revolving bodies of construction machines are equipped with a revolving motor with a brake mechanism. Figure 4 shows
FIG. 2 is a circuit diagram of a conventional brake device for parking a rotating body. In the figure, 1 is a brake mechanism attached to the swing motor 2, 6 is an electromagnetic valve, 7 is a pilot pump for discharging pressure oil that acts on the hydraulic action section 8 of the brake mechanism 1, 9 is a swing switching valve, and 10 is a main pump. , 11 is a prime mover for driving the pump, 12
is an electric circuit, 13 is a switch in the electric circuit 12,
14 is a solenoid, and 15 is a DC power supply.

Next, the brake system for parking a rotating body shown in FIG. 4 will be described. A switch 13 in the electric circuit 12 is provided near the driver's seat (not shown),
Operating lever 1 of independent opening/closing device or swing switching valve 9
6, but here we will explain the case of independent opening/closing operation. When the driver closes the switch 13 before the swing motor 2 starts operating, the solenoid 14 is energized and the solenoid valve 6 is switched from the N position to the C position. Pressure oil from the pilot pump 7 acts on the hydraulic pressure acting portion 8 of the brake mechanism 1 via the solenoid valve 6 at position C. As a result, the brake mechanism 1
The inner spring (not shown) is compressed and the brake is released. Then, when the driver switches the operating lever 16 of the swing switching valve 9 to the E or F position,
The swing motor 2 rotates forward or backward.

Next, we will discuss brake operation. When the driver returns the swing switching valve 9 from the E or F position to the neutral position, the pressure oil discharged from the main pump 10 returns to the oil tank 18, so the swing motor 2 stops operating. After that, the driver opens the switch 13. Then, the solenoid 14 is demagnetized and the solenoid valve 6 returns from the C position to the D position. Therefore,
The hydraulic force acting portion 8 of the brake mechanism 1 communicates with the oil tank 18 through the two-position drain oil passage of the solenoid valve 6, and the spring force of the spring within the brake mechanism 1 performs a brake operation.

Problems to be Solved by the Invention As mentioned above, in the conventional rotating body parking brake device, when the hydraulic force acting portion 8 of the brake mechanism 1 is communicated with the drain oil passage, the spring force of the spring inside the brake mechanism 1 is The mechanical brake is activated by the At the same time, when the swing switching valve 9 is returned to the neutral position and the swing motor 2 is stopped, a relief valve 19 connected in parallel between one port 17 and the other port 22 of the swing motor 2, Hydraulic brake action is performed by the relief setting pressure No. 19. Therefore, when the brake is activated, the swing motor with a brake mechanism receives both a mechanical parking brake force due to the spring force within the brake mechanism and a hydraulic brake force due to the relief valve of the swing motor. For example, if a hydraulic excavator collides with another object in the direction of rotation while the hydraulic excavator is operating the parking brake for the revolving structure, or if a lateral external force is applied during side excavation of the soil. Because the sum of the above mechanical parking brake torque and hydraulic brake torque is too large, there is no cushioning relief in the turning direction, causing an accident that damages gears in the swing reducer, swing pinion, ring gear, etc. in the power transmission system from the swing shaft. Something happened.

The present invention solves the above-mentioned problems and provides a brake device for parking a revolving structure of a construction machine in which only a mechanical parking brake is operated without applying a hydraulic brake force.

Means for Solving the Problems The means of this invention taken to solve the above problems are as follows: (a) When the swing motor stops operating, one port of the swing motor is connected to the other port, and the swing motor is activated. In some cases, a port communication switching valve is installed between the above two ports of the swing motor so that one port and the other port are shut off by the pilot hydraulic pressure for releasing the brake. It was configured by connecting it to the pilot oil line.

The pilot pressure receiving part of the port communication switching valve is
Since the pilot pump is connected to the brake release pilot oil passage that communicates with the brake mechanism, when the pilot pressure is applied to the brake mechanism to release the brake, the port communication switching valve is connected to one side of the swing motor. Switched to cut off the oil passage between the port and the other port.
As a result, when the driver performs a switching operation on the swing switching valve, the swing motor performs a swing operation.

(b) When the swing switch is returned to the neutral position to stop the swing motor and the pilot pressure for brake release cannot be applied, the brake mechanism operates the mechanical brake using spring force. On the other hand, since no pilot pressure is acting on the brake release pilot oil passage, the port becomes in the port communication position and short-circuits one port and the other port of the swing motor. As a result, the hydraulic braking force due to the relief setting pressure of the relief valve provided in parallel between the two ports of the swing motor does not work. Therefore, only the mechanical parking brake force acts as the brake force for parking the revolving structure of the construction machine.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a circuit diagram of the brake device of the present invention. In the figure, 1 is a brake mechanism, 2
3 is a swing motor with a brake mechanism 1, 3 is a port communication switching valve provided between one port 17 and the other port 22 of the swing motor 2, and 4 is a pilot pressure receiving part of the port communication switching valve 3, which controls pilot oil. It is connected to Route 5. Further, 20 is a hydraulic pressure acting part of the brake mechanism 1, 21 is a solenoid valve, 14 is a solenoid for the solenoid valve 21, 23 is a swing switching valve for switching the swing motor 2, and 24 is a remote control valve for controlling the swing switching valve 23. 25, 19 are relief valves, 1
8 is an oil tank, 10 is a main pump, and 11 is a pump driving motor.

Next, the configuration of the brake device of the present invention will be described with reference to FIG. In the present invention, when the swing motor 2 stops operating, one port 17 of the swing motor 2 is
The port communication switching valve 3 is connected to both ports 17 of the swing motor 2 so as to communicate between the two ports 17 and the other port 22, and to shut off one port 17 and the other port 22 by the pilot oil pressure for brake release when the swing motor 2 is in operation. , 22, and the pilot pressure receiving part 4 of the port communication switching valve 3 is connected to the brake release pilot oil passage 5,
Configured.

Next, the operation of the brake device of the present invention will be described. When the driver closes the switch 13 before the swing motor 2 starts operating, the solenoid 14 is energized.
The solenoid valve 21 is switched from the G position to the H position. Pressure oil from the pilot pump 7 is applied to the hydraulic pressure acting portion 20 of the brake mechanism 1 through the pilot oil path 5 and the solenoid valve 21 at the first position. Thereby, the spring in the brake mechanism 1 is compressed and the brake is released. At the same time, pilot pressure oil from the pilot pump 7 acts on the pilot pressure receiving portion 4 of the port communication switching valve 3 via the pilot oil passage 5 and the oil passage 27. The port communication switching valve 3 is switched from the ``re'' position to the ``nu'' position, and the port 17 and port 22 of the swing motor 2 are cut off. Then, when the driver operates the operating lever 26 of the remote control valve 24 to the ``L'' or ``O'' positions, the swing switching valve 23 is switched to the ``W'' or ``F'' positions by the pilot valves 28 and 29, and the swing motor 2 rotates in the forward direction. Or reverse operation.

Next, the case where the brake is applied will be described. When the driver returns the operating lever 26 of the remote control valve 24 from the "L" or "O" positions to the neutral position, the swing switching valve 23 also returns to its neutral position, and the swing motor 2 stops operating. After that, the driver opens the switch 13. Then, the solenoid 14 is demagnetized and the solenoid valve 21 returns from the H position to the T position. As a result, the hydraulic force acting portion 20 of the brake mechanism 1 communicates with the oil tank 18 via the to-position drain oil path of the solenoid valve 21, and the spring force of the spring within the brake mechanism 1 performs a brake operation. At the same time, the pilot pressure receiving part 4 of the port communication switching valve 3 also communicates with the oil tank 18, so the port communication switching valve 3 is switched from the N position to the R position, and the connection between the port 17 and the port 22 of the swing motor 2 is Short-circuit communication. Therefore, the hydraulic brake force of the swing motor 2 does not work, and the only brake force for parking the swing body is the mechanical parking brake force due to the spring force within the brake mechanism 1.

FIG. 2 is a hydraulic circuit diagram of another embodiment of the present invention. In the figure, 30 is a pilot switching valve provided in the middle of the oil path between the hydraulic pressure acting part 20 of the brake mechanism 1 and the pilot pump 7, 31 is a pilot pressure receiving part of the pilot switching valve 30, and 32 is a pilot pressure receiving part of the remote control valve 24. Pilot valve 28, 29
This is a high pressure selection shuttle valve connected to the output side port of the The throttle part 33 and the check valve 34 are connected in parallel and are provided in the middle of the oil path between the shuttle valve 32 and the pilot pressure receiving part 31 of the pilot switching valve 30, and are used for a brake operation delay function. First, the brake release operation will be described.
In order for the driver to operate the swing motor 2 to swing,
When the operation lever 26 of the remote control valve 24 is operated to the ``L'' or ``O'' positions, the pilot pressure from the pilot pump 7 is transferred to the pilot switching valve 30 via the shuttle valve 32 and the check valve 34 by either the pilot valve 28 or 29. It acts on the pressure receiving part 31. Then, the pilot switching valve 30 switches from the horizontal position to the vertical position, and the pressure oil from the pilot pump 7 is transferred to the pilot switching valve 3.
0, the brake is applied to the hydraulic pressure acting section 20 of the brake mechanism 1 via the pilot oil passage 5, so that the brake is released. At the same time, the port communication switching valve 3 is switched from the ``re'' position to the ``nu'' position, and the swing motor 2
Port 17 and port 22 are cut off.
Therefore, the pilot pressure from the pilot valve 28 or 29 of the remote control valve 24 switches the swing switching valve 23 to the W position or the F position, and the swing motor 2 rotates forward or reverse.

Next, referring to FIG. 2, the case where the brake is applied will be described. When the operator returns the operating lever 26 of the remote control valve 24 from the ``L'' or ``O'' positions to the neutral position in order to stop the swing motor 2, the pilot pressure from the pilot valve 28 or 29 changes to the pilot pressure of the pilot switching valve 30. Since it no longer acts on the pressure receiving portion 31, the pilot switching valve 30 returns to the Y position from the T position. However, the return oil from the pilot pressure receiving part 31 is transferred to the throttle part 33.
through the shuttle valve 32 and into the oil tank 18.
Therefore, the braking force due to the spring force of the brake mechanism 1 is gradually activated. On the other hand, brake mechanism 1
The pilot oil passage 5 connected to the hydraulic pressure acting portion 20 communicates with the oil tank 18 through the Y position of the pilot switching valve 30, so that the port communication switching valve 3 is switched from the N position to the R position. As a result, a short circuit is established between the port 17 and the port 22 of the swing motor 2, and the hydraulic braking force of the swing motor 2 is no longer applied.

Next, FIG. 3 is a circuit diagram of another embodiment of the present invention. In FIG. 3, a port communication switching solenoid valve 35 is used in place of the port communication switching valve 3 in FIG. A solenoid 14' for actuating the solenoid valve 35 is therefore provided in the electrical circuit 12'.
If the operator closes the switch 13 in the electric circuit 12' before activating the swing motor 2, the swing vehicle parking brake is released as described in FIG. At the same time, the solenoid 14' is also energized, the port communication switching solenoid valve 35 is switched from the "S" position to the "R" position, and the port 17 and port 22 of the swing motor 2 shut off the oil passage. The swing motor 2 can be activated by operation. Further, the driver returns the operating lever 26 to the neutral position to stop the operation of the swing motor 2. When the switch 13 is opened, the solenoids 14 and 14' are demagnetized, and the solenoid valves 21 and 35 are respectively switched from the H position to the T position and from the R position to the S position. As a result, the hydraulic pressure acting part 20 of the brake mechanism 1 communicates with the drain oil passage of the solenoid valve 21 at the t position, and short-circuit communication occurs between the port 17 and the port 22 of the swing motor 2, and the hydraulic brake of the swing motor 2 is connected. Power ceases to work. Therefore, the brake force for parking the rotating body is only the mechanical parking brake force due to the spring force within the brake mechanism 1.

Effects of the Invention As mentioned above, in the brake device of the present invention, a port communication switching valve is provided between one port and the other port of the swing motor with a brake mechanism, and the pilot pressure receiving part of the port communication switching valve is used as a brake. Connected to the pilot oil line for releasing the brake of the mechanism. When the brake mechanism is applying the brake force using the spring force, the port communication switching valve is configured to communicate the oil passage between the two ports of the swing motor. Hydraulic brake force does not work, but only mechanical parking brake force, which is generated by the spring force within the brake mechanism, works. In the conventional technology, when the swing switching valve is returned to the neutral position to stop the swing motor and apply the brake, both the mechanical parking brake force due to the spring force within the brake mechanism and the hydraulic brake force due to the relief valve of the swing motor are applied. was working. Therefore, if a large external force in the swinging direction is applied to the work attachment on the front part of the upper revolving structure when the parking brake for the revolving superstructure is activated, a buffer relief in the swinging direction may be applied. This has caused accidents in which gears in the swing reducer, swing pinion, ring gear, etc. in the power transmission system are damaged from the swing shaft. However, in the present invention, a port communication switching valve is provided so that hydraulic brake torque is not generated when the rotating body parking brake is activated, so that only the mechanical parking brake torque resists the external force in the turning direction. Therefore, when the above-mentioned external force is excessive, the brake torque is difficult to resist, and a cushioning relief can now be generated.

As described above, the brake system of the present invention reduces the excessive brake torque when the brake of the swing motor with a brake mechanism is activated, and prevents damage to the swing power transmission system components of construction machinery, thereby increasing safety. and economic efficiency can be improved.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the brake device of the present invention, Figure 2
3 and 3 are respectively circuit diagrams of other embodiments of the present invention, and FIG. 4 is a circuit diagram of a prior art brake device. 1...brake mechanism, 2...swivel motor, 3...
... Port communication switching valve, 4 ... Pilot pressure receiving section, 5 ... Pilot oil path, 6, 21, 35 ...
Solenoid valve, 7... Pilot pump, 8, 20...
Hydraulic pressure acting part, 9, 23...Swivel switching valve, 12,
12'... Electric circuit, 17, 22... Port, 2
4...Remote control valve.

Claims (1)

[Scope of utility model registration request] A brake for parking a revolving body of a construction machine, which has an upper revolving body and is equipped with a brake mechanism 1 in which the brake is actuated by a spring force on the revolving shaft of the upper revolving body, and the brake is released by hydraulic pressure. In the device, when the swing motor 2 is stopped, one port 17 and the other port 22 of the swing motor 2 are connected to each other, and when the swing motor 2 is activated, one port 17 and the other port 22 are connected by the pilot hydraulic pressure for brake release. Turn the port communication switching valve 3 so as to shut off both ports 1 of the motor 2.
7 and 22, and the pilot pressure receiving part 4 of the port communication switching valve 3 is connected to a brake release pilot oil passage 5.