JPS5820694Y2 - trencher control device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a trencher control device.

Conventionally, in a trencher that excavates while traveling, if an excessive load is applied to the excavation attachment due to the excavation blade biting a stone or digging at a speed higher than the appropriate speed while working with the excavation attachment, the excavation attachment The attachment operating fluid pressure motor is stopped by the action of a relief valve provided in its circuit.

However, since the travel motor is not controlled, the vehicle will continue to travel as it is, which may put strain on the attachment and cause damage.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control device that eliminates the above-mentioned conventional drawbacks and protects the excavation attachment from being subjected to excessive loads during excavation work.

Hereinafter, embodiments of the present invention will be explained based on FIGS. 1 and 2. The control device according to the present invention is a driving system that connects a driving fluid pressure motor 1 and a fluid pressure pump 2 for driving the motor. An unload relief valve 4 is provided in a circuit 3, and a pilot relief valve 9 is provided in an attachment circuit 8 that connects a fluid pressure motor 6 that operates an attachment 5 for excavating while traveling and a fluid pressure pump 7 for driving the motor. The unload relief valve 4 and the pilot relief valve 9 are both opened at a set pressure P2, and when the attachment circuit 8 reaches the pressure P2, the pilot relief valve 9 opens and operates. The load relief valve 4 is configured to allow the fluid in the traveling circuit 3 to flow out into the tank 10, and the set pressure P1 of the attachment circuit 8 is set to the set pressure P2 of both of the relief valves.
It is something that has been lowered.

Reference numeral 9a designates a working fluid passage leading from the pilot relief valve 9 to the unload relief valve 4, 11 a tank, and 12 a switching valve provided in the attachment circuit 8.

13 is a trencher body provided with a driver's seat 14;
Reference numeral 5 denotes running wheels driven by the running motor 1 of the running circuit 3.

The excavation attachment 5 is attached to the front of the trencher main body 13 via a support bracket 16, and includes a case 17, an endless belt 19 housed in the case and having a large number of excavation blades 18, and supporting the belt. Sheave 2
The belt 19 is driven by the attachment motor 6 of the attachment circuit 8.

Next, the effect will be explained.

In the trencher, when excavating with the excavating attachment 5, the motor 6 of the attachment circuit 8 is rotated, and the sheaves 20, 2 of the attachment 5 are rotated.
At the same time, the belt 19 is driven through the belt 19 via the belt 19, the motor 1 of the traveling circuit 3 is rotated, and the trencher is moved backward at a set appropriate speed while excavating work is performed using the excavating blade 18 provided on the belt 19.

In this case, the attachment motor 6 rotates continuously until the pressure in the circuit 8 reaches the set pressure P1, and the attachment 5 is operated to perform the work.

During work, when the digging blade 18 bites into a stone or digs at a speed higher than the set appropriate speed, an unreasonable load is applied to the attachment 5 and the fluid pressure in the attachment circuit 8 rises to P2. Circuit pilot relief valve 9
opens, and the fluid in the attachment circuit 8 acts on the unload valve 4 of the travel circuit 3 to open it, thereby returning the fluid in the travel circuit 3 to the tank 10, stopping the travel motor 1, and opening the trencher. The attachment 5 is stopped, and the excavation work by the excavation blade 18 is performed in the stopped state.
prevent overload from being applied to the

As is clear from the above description, the trencher control device according to the present invention includes an unload relief valve in the traveling circuit, a pilot relief valve in the attachment circuit, and the unload relief valve 4 and the pilot relief valve. 9 are made to open at a set pressure P2, and when the attachment circuit 8 reaches the pressure P2, the pilot relief valve 9 opens and operates, and the unload relief valve 4 is activated to open the travel circuit 3. Since the fluid is made to flow out into the tank 10, when the attachment is overloaded during excavation work and the fluid pressure in the attachment circuit reaches P2, the pilot relief valve of the circuit opens and the attachment circuit opens. The fluid acts on the unload relief valve in the travel circuit, opening it and returning the fluid in the travel circuit to the tank, stopping the travel motor and trencher, stopping the excavation operation, and preventing overload from being applied to the attachment. can be prevented.

In addition, in the present invention, the set pressure P1 of the attachment circuit 8 is lower than the set pressure P2 of the side IJ leaf valve, so that continuous excavation is performed by the attachment until the fluid pressure of the attachment circuit reaches P□. It has an excellent effect of being able to do the following.

[Brief explanation of drawings]

The drawings relate to an embodiment of the trencher control device of the present invention, and FIG. 1 is a side view of the trencher, and FIG. 2 is a control circuit diagram thereof. 1: Fluid pressure motor for traveling, 2: Fluid pressure pump for driving the same motor, 3: Traveling circuit, 4: Unload relief valve, 5
: Excavation attachment, 6: Motor for operating the attachment, 7: Fluid pressure pump for driving the motor, 8: Attachment circuit, 9: Pilot relief valve, 10: Tank.

Claims (1)

[Scope of utility model registration request] A hydraulic motor for driving 1 and a hydraulic pump for driving the motor 2
An unload relief valve 4 is provided in the running circuit 3 connecting the drive circuit 3 to the attachment circuit 8 connecting the fluid pressure motor 6 that operates the attachment 5 for excavating while running and the fluid pressure pump 7 for driving the motor. A pilot relief valve 9 is provided, the unload relief valve 4 and the pilot relief valve 9 are both opened at a set pressure P2, and the attachment circuit 8 is opened at a set pressure P2.
When the pressure is reached, the pilot relief valve 9 opens and operates to operate the unload relief valve 4 to cause the fluid in the running circuit 3 to flow out to the tank 10, and the set pressure P1 of the attachment circuit 8 is set to Side IJ IJ
- A control device for a trencher, characterized in that the pressure is set lower than a set pressure P2 of a valve.