JPH083473Y2 - Swing lock circuit of hydraulic construction machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing lock circuit in a swing system of a hydraulic construction machine such as a hydraulic excavator.

[0002]

2. Description of the Related Art A hydraulic circuit of a swing system of a hydraulic construction machine such as a hydraulic excavator that has been generally used will be described with reference to FIG. 2. The pressure oil discharged from a hydraulic pump A is a swing control valve. The direction and flow rate are controlled by B and introduced into the swing motor C, and the actuator C1
To rotate the swivel C0 of the hydraulic construction machine,
That is, the hydraulic construction machine is turned.

The turning control valve B is switched to supply or cut off the pressure oil from the auxiliary hydraulic power source N by the operation of the pilot valve D, and is inputted as an operation signal through the operation signal transmitting oil passages K and L. The direction and flow rate of the pressure oil discharged from the hydraulic pump A are controlled.

The swing motor C is provided with a parking brake C2 for fixing the swivel base C0 at the time of parking or a work in which the swing operation is not performed. , The parking brake C2 is turned on (braking operation) by supplying or shutting off through the oil passage P.
Turn off (release braking operation).

A shuttle valve E is provided in a bypass passage M that connects the operation signal transmitting oil passages K and L, and the pressure from the shuttle valve E is guided to a pressure switch F via an oil passage Q and is increased. When the switch F is turned on / off and the on / off signal of the pressure switch F is input to the controller G, the controller G causes the solenoid valve I to turn the swing lock switch H.
The solenoid valve I is switched by outputting a switching signal via.

The turning lock switch H turns on / off a switching signal from the controller G, and the parking brake C2 turns by turning the pilot valve D while the turning lock switch H is off (turning lock release). Control valve B is switched to actuator C
The braking is released only when 1 operates.

[0007]

However, in the hydraulic circuit of the swing system of the conventional hydraulic construction machine described above, the pilot valve D is operated while the swing lock switch H is on (swing lock). When the operation is performed, the parking control valve B is switched, and when the actuator C1 turns, the parking brake C
No. 2 is not released, and the parking brake C2 receives the starting torque of the actuator C1 at all times, and the braking load of the parking brake C2 is large, and there is a possibility that durability is deteriorated such as accelerated wear.

Further, when the braking force of the parking brake C2 is reduced due to wear or damage of the parking brake C2 and the starting torque of the actuator C1 is reduced, the turning lock switch H is turned on (turning lock). Regardless, there is a risk that when the pilot valve D is operated and the turning operation is performed, the swivel base C0 is rotated by the actuator C1.

An object of the present invention is to improve the durability of a parking brake and to secure the safety when the parking brake has a reduced braking force due to wear or damage. It is to provide a circuit.

[0010]

A swing lock circuit of a hydraulic construction machine according to the present invention outputs a switching control signal based on a detection signal such as a pressure switch for detecting a swing operation and a detection signal from the detection means. And a brake control means such as a solenoid valve that turns on and off the parking brake based on the output from the controller.When the turning operation is performed, the brake is released instantly, and when the turning operation is not performed, a predetermined operation is performed. In a swing brake device of a hydraulic construction machine that activates a parking brake after a lapse of time, a swing lock switch connected to a controller in parallel with the detection means,
A solenoid valve is provided which is switched by turning on / off the swing lock switch and is arranged between the swing operation signal oil passage and the tank. When the swing lock switch is turned on (swing lock), the solenoid valve swings. The signal oil passage and the tank are made to communicate with each other to disable the turning motor, and a parking non-operation detection signal (for example, an off signal of the pressure switch) of the detecting means makes the parking brake in the operating state, while the turning is performed. Lock switch is off (turn lock release)
Then, the solenoid valve is turned off, pressure is generated in the turning operation signal oil passage to enable the turning motor, and the parking brake is released by the turning operation detection signal (for example, pressure switch ON signal) of the detection means. When the swing lock switch is turned on (swing lock), no pressure is generated in the swing operation signal oil passage even if the operator performs a swing operation, so the swing motor does not operate and the parking brake is applied. The durability of the parking brake can be improved without load, and the parking brake
Even when the performance is deteriorated due to wear or damage, a turning operation is not generated, and high safety can be secured.

[0011]

Embodiment An embodiment of the present invention will be described with reference to FIG.
The direction and flow rate of the pressure oil discharged from the hydraulic pump 1 are controlled by the turning control valve 2, and the turning motor 3
The actuator 30 is driven to rotate the swivel base 31 on which the hydraulic construction machine is placed.

The turning control valve 2 is switched to supply or cut off the pressure oil from the auxiliary hydraulic power source 5 by operating the pilot valve 4, and is inputted as an operation signal through the operation signal transmitting oil passages 6 and 7. The direction of the pressure oil discharged from the hydraulic pump 1 (determines the rotation direction of the actuator 30) and the flow rate (determines the speed of the actuator 30) are controlled.

A parking brake 32 for fixing the swivel base 31 to the swing motor 3 at the time of parking or a work not performing a swing operation.
Is provided and the pressure oil from the auxiliary hydraulic power source 10 is switched by the switching operation of the brake electromagnetic valve (brake control means) 8 via the oil passage 91, the brake electromagnetic valve 8 and the oil passage 92.
The parking brake 32 is turned on (brake) and turned off (brake released) by shutting off or supplying it to 32.

The brake solenoid valve 8 is switched between a position (brake release position) 83 when the drive coil 81 is energized and a position (brake position) 82 when the drive coil 81 is de-energized. Is the controller 12
Controlled by the switching signal output from the controller
12 is connected to a power supply 14 via a pressure switch 13,
When the ON / OFF signal of the pressure switch 13 is input to the controller 12, the controller 12 outputs a switching signal to the drive coil 81.

A shuttle valve 17 is provided in a bypass passage 16 that connects the operation signal transmitting oil passages 6 and 7, and the pressure from the shuttle valve 17 is switched via an oil passage 18 to a pressure switch.
The oil passage 181 branched to the oil passage 18 is connected to a solenoid valve (for discharging pressure oil) 19, and the solenoid valve 19 is in position 192 when the drive coil 191 is off, so that the oil passage 181 To secure the pressure in the oil passage 18 to reliably turn the pressure switch 13 on and off, and when the drive coil 191 is on, the position is 193 and the oil passage 181 communicates with the tank 20. The pressure oil in the oil passage 18 is released.

The drive coil 191 of the solenoid valve 19 is a controller
12 and the swing lock switch 15 are connected to the power supply 14, and when the on / off signal of the swing lock switch 15 is input to the controller 12, a switching signal is output from the controller 12 to the drive coil 191 to drive the drive coil. Turn the 191 on and off.

Here, the controller 12 is a pressure switch.
When 13 is turned on, the drive coil 81 of the brake solenoid valve 8 is energized (turned on) without any time delay, and the position (brake release position) 83 is quickly switched to release the parking brake 32.
When the pressure switch 13 is turned off, the drive coil 81 of the brake solenoid valve 8 is deenergized (off) with a predetermined time delay, the parking brake 32 is operated with the time delay, and the swing lock switch 15 is turned on (swing lock). Drive coil 19 of solenoid valve 19 without delay
When 1 is energized (turned on) and the swing lock switch 15 is turned off (turn lock is unlocked), the drive coil 191 of the solenoid valve 19 is shut off (off) without a time delay.

Next, the operation will be described. An operator operates the pilot valve 4 to generate a pressure in the oil passage 6 or 7 by the pressure oil from the auxiliary hydraulic power source 5, and switches the turning control valve 2 to switch the hydraulic pump 1 The pressure oil from is supplied to the swing motor 3, and the swing motor 3 becomes operable.

Here, when the swing lock switch 15 is off (the swing lock is released), the pilot valve 4
As described above, when the swing lock switch 15 is turned off, the drive coil 191 of the solenoid valve 19 is turned off to the position 192, and the oil passage 181 is shut off. Therefore, the pressure generated in the oil passage 6 or 7 is Is guided to the pressure switch 13 via the shuttle valve 17 and the oil passage 18 to turn on the pressure switch 13, and the controller 12 energizes (turns on) the drive coil 81 of the brake solenoid valve 8 without a time delay and moves to the position (brake). Release position)
By switching to 83, the pressure oil from the auxiliary hydraulic power source 10 is supplied to the parking brake 32 via the oil passage 91, the brake electromagnetic valve 8, and the oil passage 92, and the brake motor is released, whereby the turning motor 3 can be operated. Become.

Next, when the swing lock switch 15 is turned on (swing lock), the drive coil 19 of the solenoid valve 19 is turned on.
1 is turned on to the position 193, and the oil passage 181 communicates with the tank 20 to release the pressure in the oil passage 18. Therefore, the pilot valve 4 is operated to operate the auxiliary hydraulic pressure supplied to the oil passage 6 or 7. The pressure oil from the source 5 is the shuttle valve 17 and the oil passage 1
It is guided to the tank 20 via 8, 181 and the oil passages 6, 7, 18, 1
Since the pressure in 81 becomes equal to the pressure in the tank 20 (which is almost zero), the swing control valve 2 is not switched, the actuator 30 of the swing motor 3 does not operate, and the pressure switch 13 is off. Therefore, the controller 12 turns off the drive coil 81 of the brake solenoid valve 8,
The brake solenoid valve 8 is switched to the position (brake position) 82 to hold the parking brake 32 in the on state (brake state).

As described above, even when the operator operates the pilot valve 4 while the swing lock switch 15 is turned on (swing lock), the swing control valve 2 is not switched, and the actuator 30 of the swing motor 3 is operated.
Will not operate and the parking brake 32 will not be overloaded, and the durability of the parking brake 32 can be improved.Also, when the parking brake 32 wears, is damaged, etc. High safety can be secured without causing

[0022]

Since the present invention is configured as described above, it has the following effects. When the swing lock switch is turned on (swing lock), the solenoid valve makes the swing operation signal oil passage communicate with the tank to make the swing motor inoperable, and the swing non-operation detection signal of the detection means causes the parking brake to operate. By putting the parking brake in the operating state, it is possible to improve the durability of the parking brake without imposing a load on the parking brake, and also when the parking brake deteriorates due to wear or damage, a turning operation occurs. High security can be ensured without
When the swing lock switch is turned off (the swing lock is released), the solenoid valve is turned off to generate pressure in the swing operation signal oil passage to enable the swing motor and to detect the swing operation detection signal from the detection means. By releasing the parking brake, it is possible to improve the durability of the parking brake without unnecessarily operating the parking brake and without imposing a load on the parking brake.

[Brief description of drawings]

FIG. 1 is a schematic system diagram of a swing lock circuit of a hydraulic construction machine according to the present invention.

FIG. 2 is a schematic system diagram of a conventional turning system for a hydraulic construction machine.

[Explanation of symbols]

 1 hydraulic pump 2 swing control valve 3 swing motor 4 pilot valve 8 brake solenoid valve 12 controller 13 swing switch 15 swing lock switch 17 shuttle valve 19 solenoid valve (for pressure oil discharge)

Claims (1)

[Scope of utility model registration request] 1. A detection means for detecting a turning operation, a controller for outputting a switching control signal based on a detection signal from the detection means, and a brake control means for turning on / off a parking brake based on the output from the controller. In the swing brake device of the hydraulic construction machine, which releases the brake instantly when the swing operation is performed and activates the parking brake after a predetermined time when the swing operation is not performed, is connected to the controller in parallel with the detection means. Swivel lock switch and on / off of the swivel lock switch
It is provided with a solenoid valve which is switched by being turned off and which is arranged between the swing operation signal oil passage and the tank. When the swing lock switch is turned on (swing lock), the solenoid valve connects the swing operation signal oil passage and the tank. While making the turning motor inoperable by communicating, the parking brake is activated by the turning non-operation detection signal of the detecting means, while the solenoid valve is turned off when the turning lock switch is turned off (turning lock release). A swing lock circuit for a hydraulic construction machine, wherein pressure is generated in a swing operation signal oil passage to enable a swing motor to operate, and a parking brake is released by a swing operation detection signal of a detection means.