JP2511618Y2 - Break circuit device for hydraulic equipment - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake circuit device for hydraulic equipment, and more particularly to a brake circuit device for releasing a brake of a swing body provided in a hydraulic shovel or the like.

[0002]

2. Description of the Related Art Hydraulic equipment such as a hydraulic excavator is formed so that a revolving structure is fixed by a brake and the brake is released by a hydraulic actuator so that the structure can be rotated.
FIG. 4 shows a conventional brake circuit. In FIG. 1, reference numeral 1 denotes a revolving superstructure, and 2 denotes a hydraulic motor for revolving.
Drive. The direction switching valve 4 is pilot-operated by a turning operation lever 5.

[0003] Although not shown, a brake device is interposed between the revolving unit 1 and the main body, and a brake is constantly applied to the revolving unit 1 to prevent the revolving unit 1 from rotating. A brake release cylinder 6 is connected to the brake device. When pressure oil is introduced into the brake release cylinder 6, the brake is released and the revolving unit 1 can be rotated. In the circuit shown in FIG.
When the engine of the hydraulic device is started, the pilot hydraulic pump 7 rotates and sends pressure oil to the brake release cylinder 6 to release the brake.

FIG. 5 shows another brake circuit. When the operating lever 5 is rotated, pilot pressure is generated and the directional control valve 4
Is moved from the neutral position C, the pressure switch 8 is turned on, and the solenoid valve 9 is switched. As a result, the pressure oil of the pilot hydraulic pump 7 is guided to the brake release cylinder 6, the brake is released, and the revolving unit 1 can rotate. When the turning operation lever 5 is returned to the neutral position, the solenoid valve 9 returns to the position shown in the drawing after a certain period of time due to the action of the off-delay timer 10, and the pressure oil of the brake release cylinder 6 is led out to the tank 11. Then, the revolving superstructure 1 is braked and fixed again.

[0005]

In the brake circuit shown in FIG. 4, the brake is always released while the engine is rotating. Therefore, there is a problem that when the operating lever is set to the neutral position in a state where the body is tilted on an inclined ground or the like, the revolving body rotates due to leakage of the hydraulic motor for turning. On the other hand, in the case of turning on / off the brake by the electromagnetic switching valve shown in FIG. 5, the revolving structure is fixed by the brake when the operation lever is in the neutral position. If an external force in the turning direction is applied to the work attachment attached to the revolving structure in a fixed state, the attachment and the revolving structure will be overloaded, so if the brake torque is set low and an external force exceeding a certain value is applied, This prevents the revolving superstructure from rotating and overloading. Therefore, when transporting hydraulic equipment, the revolving unit must be fixed by a lock mechanism using pins or the like to prevent the revolving unit from rotating due to vibration or the like, and there is a disadvantage that the mechanism and operation become complicated. .

In view of the above, a brake circuit has been provided which has improved operability and durability by preventing the revolving structure from rotating freely and preventing the work attachment from being overloaded at the time of work without complicating the mechanism. Therefore, a technical problem to be solved arises, and an object of the present invention is to solve this problem.

[0007]

This invention has been proposed in order to achieve the above-mentioned object, and a brake for preventing the rotation of the swing structure of the construction machine is formed so that it can be released by hydraulic pressure. And the revolving structure is a revolving structure operating lever
In a brake circuit device of a hydraulic device that is configured to turn by the operation of a brake release cylinder and a pyro
A pressure reducing valve and a solenoid switching valve in the line between the
Insert the pilot hydraulic pump when the engine is stopped
Stop and the pressure oil from the pilot hydraulic pump is
Not supplied to the rake release cylinder, and engine start
When the revolving structure control lever is in the neutral position,
Due to the switching operation of the electromagnetic switching valve,
Pressure oil from the pilot hydraulic pump after switching to the dynamic position
Is reduced and supplied to the brake release cylinder.
When the revolving structure operation lever is turned, the electromagnetic switching
When the valve is switched, the spool or poppet of the pressure reducing valve is changed to a position where the pressure can be released , and the position is fixed.
The present invention provides a brake circuit device for hydraulic equipment, which is characterized in that it can be set .

[0008]

[Operation] Brake release cylinder of revolving structure and pilot oil
A pressure reducing valve and an electromagnetic switching valve are installed in the line between the pressure pump and
However, when the engine is stopped, the pilot hydraulic pump
Pump stops and the pressure from the pilot hydraulic pump
No oil is supplied to the brake release cylinder
Therefore, 100% of the brake torque acts on the revolving structure.
The revolving structure can be securely fixed. Also, at engine start
If the revolving structure control lever is in the neutral position,
The pressure reducing valve is placed in the pressure reducing operating position by the switching operation of the magnetic switching valve.
It is switched to reduce the pressure oil from the pilot hydraulic pump.
Is supplied to the brake release cylinder. That is, depressurized pressure oil is supplied to the brake release cylinder, and the brake is released in proportion to the reduced pressure. Like this,
Brake torque is reduced and the revolving structure is being braked.
Therefore, when an excessive external force is applied to the work attachment, the revolving structure is rotated by the external force, and an overload on the work attachment and the revolving structure can be prevented. Also, when the revolving structure operating lever is rotated, the revolving structure operating lever is operated.
Is switched electromagnetic switching valve in conjunction with the work, the spool or poppet of the pressure reducing valve is solid <br/> constant I switched to vacuum release position, the brake release cylinder without discharge amount of the pilot hydraulic pump is depressurized And the brake is completely released to prevent the rotation of the swing structure from being hindered.

When the revolving structure operating lever is turned,
The pressure reducing valve is linked to the revolving structure operation lever and the spool or poppet is fixed at the decompression release position, and the oil discharged from the hydraulic pump reaches the brake release cylinder without decompressing and completely releases the brake to rotate the revolving structure. Does not hinder.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described in detail below with reference to FIG. In the figure, reference numeral 21 denotes a swing body such as a hydraulic shovel,
Driven by the hydraulic motor 22. Hydraulic motor 22
Is connected to a main hydraulic pump 24 via a direction switching valve 23, and connects two main pipelines 25, 26 to check valves 27, 26.
28 and the relief valves 29 and 30, the pressure in the main pipelines 25 and 26 is limited to a certain value or less. The revolving unit 21 is provided with a brake device (not shown), and when the engine is stopped, a brake is applied to the revolving unit 21 to prevent rotation. The brake is released by introducing pressure oil to the brake release cylinder 31, and the revolving unit 2
1 becomes rotatable.

Direction switching valve 23 and brake release cylinder 3
1 is driven by a pilot hydraulic pump 32.
The direction switching valve 23 switches the spool of the direction switching valve 23 to the A position or the B position by rotating the revolving body operation lever 33 from the neutral position to one of the left and right in FIG.
The hydraulic motor 22 is rotated forward or backward. On the other hand, an electromagnetic switching valve 35 and a pressure reducing valve 36 are inserted in a pilot conduit 34 that connects the brake release cylinder 31 and the pilot hydraulic pump 32.

The electromagnetic switching valve 35 has ports A and P, B and R connected when the spool is in the D position, and AB when the spool is in the E position.
It becomes P connection. The pressure reducing valve 36 is AP-connected at the N position and AR-connected at the R position. The pressure of the spring 37 can be adjusted by an adjusting screw (not shown), and the amount of pressure reduction can be freely set. Here, if the pressure of the pilot hydraulic pump 32 is Pβ and the set pressure of the pressure reducing valve 36 is Pα, Pβ> Pα
Is set so that

The electromagnetic switching valve 35 is switched to the E position when the pressure switch 42 is turned on via the shuttle valve 41 which connects the pilot pipe paths 39 and 40 in the two directions of the operation portion 38. An off-delay timer 43 is inserted between the pressure switch 42 and the electromagnetic switching valve 35, and the revolving structure control lever 3
When 3 is returned to the neutral position, the return of the spool of the electromagnetic switching valve 35 to the D position is delayed to delay the operation of the brake, so that the revolving structure 21 can be smoothly stopped.

Next, the operation of the brake circuit device will be described. First, when the engine is stopped, as shown in FIG. 1, the electromagnetic switching valve 35 is in the D position, the pilot hydraulic pump 32 is stopped, pressure oil is not sent to the brake release cylinder 31, and the revolving unit 21 is moved by the brake device. It is fixed. Next, when the engine is started and the pilot hydraulic pump 32 is driven, when the swing structure operating lever 33 is at the neutral position, the electromagnetic switching valve 35 is at the D position as described above.
Further, since the pressure reducing valve 36 is at the N position, pressure oil is introduced into the brake releasing cylinder 31 and operated in the brake releasing direction. At the same time, as the pressure in the pilot passage 34 and the pilot passage 44 on the R side of the pressure reducing valve 36 increases, the spool of the pressure reducing valve 36 is switched to the R position as shown in FIG. 2, and the pressure in the pilot pipe 34 is reduced. The pressure reducing valve 36 is the spring 3
The secondary pressure is controlled to Pα by the set pressure Pα of 7, and a constant pressure Pα is applied to the brake release cylinder 31 to set the brake torque to α%. Therefore, for example, during excavation work by the excavation attachment provided on the revolving structure 21, when a moment in the rotation direction is applied to the revolving structure 21 due to excavation resistance, when the moment exceeds the brake torque of α%, the revolving structure 21 will Rotate. As a result, the load on the excavation attachment is limited to a certain value or less, and damage or failure of the attachment due to overload is prevented.

Next, when the revolving structure 21 is rotated, pressure oil is led from the shuttle valve 41 to the pressure switch 42 by the operation of the revolving structure operating lever 33, the pressure switch 42 is turned on, and as shown in FIG. Then, the spool of the electromagnetic switching valve 35 is switched to the E position. As a result, pressure is applied from the B port of the electromagnetic switching valve 35 to the pilot passage 45 on the N side of the pressure reducing valve 36, and the R position is switched to the N position as shown in FIG.

Since the discharge pressures of the A and B ports of the electromagnetic switching valve 35 are equal, the pressures applied to the two pilot passages 44 and 45 of the pressure reducing valve 36 are equal, and the pressure of the spring 37 causes the spool of the pressure reducing valve 36 to move. Fixed in N position. Accordingly, since the pressure reducing action of the pressure reducing valve 36 does not work, the discharge pressure Pβ of the pilot hydraulic pump 32 is applied to the brake release cylinder 31 without being reduced, and the brake is completely released and does not hinder the rotation of the revolving unit 21. .

When the swing body operating lever 33 is returned to the neutral position, the hydraulic pressure to the pressure switch 42 is canceled through the shuttle valve 41, and the pressure switch 42 is turned off. Then, the off-delay timer 43 causes the electromagnetic switching valve 35 to return to the D position after a certain period of time. As a result, the pressure on the N-side pilot passage 45 of the pressure reducing valve 36 is cut off, and the pressure Pβ of the pilot hydraulic pump 32 is higher than the set pressure Pα of the spring 37. Therefore, the spool of the pressure reducing valve 36 moves to the R position. It moves and reduces the pressure Pβ of the pilot hydraulic pump 32 to Pα. Therefore, pressure oil of pressure Pα is introduced into the brake release cylinder 31 to control the brake torque to α%.

The present invention can be modified in various ways without departing from the spirit of the invention, and it goes without saying that the invention covers such modifications.

[0019]

The present invention is constructed as described in detail in the above embodiment, so that the pilot can be operated when the engine is stopped.
Hydraulic pump stopped, and the pilot hydraulic pump
Pressure oil may be supplied to the brake release cylinder.
Because there is no , the brake turns with 100% brake torque
Acting on the body can be reliably fixed to the swing body. Therefore, exports
Need a lock mechanism to prevent the revolving structure from idling during feeding.
Therefore, it can contribute to the improvement of durability and operability. Also, when the engine is started and the swing control lever is in the neutral position.
The pressure reducing valve is operated by switching the electromagnetic switching valve.
Pressure oil from the pilot hydraulic pump after switching to the dynamic position
Will be decompressed and supplied to the brake release cylinder
Therefore, the brake torque of the swing structure has been reduced by a certain amount.
In this state, the revolving structure is fixed. Therefore, if the attachment mounted to said pivot member external force of the turning direction is applied more than a certain value, the turning body is rotated by the load, it is possible to prevent the overloading of the working attachment is applied. Therefore, it is possible to prevent the attachment and the swing body from being damaged due to overload during work . Furthermore, the en
When the gin is started,
When it is made, the electromagnetic switching valve is switched to reduce the pressure.
Position where the valve spool or poppet can be depressurized
It's configured to switch and fix its position
Therefore, the pressure reducing action of the pressure reducing valve does not work.
The pressure oil from the hydraulic
The brake is completely released after it is added to the release cylinder.
The rotation of the revolving structure is not obstructed, and the circle
A smooth pivoting motion will be performed.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing a position of a spool when an engine is stopped.

FIG. 2 is a hydraulic circuit diagram showing the position of a spool when the engine is rotating.

FIG. 3 is a hydraulic circuit diagram showing the position of the spool during a turning operation.

FIG. 4 is a conventional brake circuit diagram.

FIG. 5 is a conventional brake circuit diagram.

[Explanation of symbols]

 21 revolving structure 31 brake release cylinder 32 pilot hydraulic pump 33 revolving structure operating lever 34 pilot line 35 electromagnetic switching valve 36 pressure reducing valve 37 spring 44, 45 pilot passage

Claims (1)

(57) [Scope of utility model registration request] 1. A brake for preventing the swing of a revolving structure of a construction machine from being hydraulically released , and
The revolving structure can be revolved by operating the revolving structure operating lever.
At a hydraulic equipment of the braking circuit device constructed urchin, Bed
Pipe between rake release cylinder and pilot hydraulic pump
Insert a pressure reducing valve and an electromagnetic switching valve into the passage to stop the engine
Is the pilot hydraulic pump stopped and the pilot oil
The pressure oil from the pressure pump is supplied to the brake release cylinder.
And the revolving structure operation lever is
Is in the neutral position, the switching operation of the solenoid switching valve
The pressure reducing valve is switched to the pressure reducing operating position by
Reduce the pressure oil from the lot hydraulic pump to release the brake.
Supply it to the Linda, and further rotate the revolving structure control lever.
When it is made, the electromagnetic switching valve is switched to a position where the pressure reducing spool or poppet can be depressurized.
A brake circuit device for a hydraulic device, characterized in that it can be switched and its position can be fixed .