JPH0533366A - Preventing device for service machine from interfering - Google Patents

Abstract

PURPOSE:To prevent full operation from being automatically locked by stopping operation automatically in dangerous side areas only for boom upper-side, arm excavation, and offset left side, and by enabling operation in a safety area and swing operation to be performed after automatic stop. CONSTITUTION:On the way of a moving-up side hydraulic-circuit 3 to a boom cylinder 2 from a boom direction-switching valve 1, and an excavating side hydraulic-circuit 7 to an arm cylinder 6 from an arm direction-switching valve 5, first and second solenoid valves 9, 10 for interrupting the circuits 3, 7 respectively are arranged. After that, a hydraulic circuit 13 to an offset cylinder 12 from an offset direction-switching valve 11 is provided with a pilot check valve 15, and it is connected to a third solenoid valve 16 for interrupting feed oil to a rod side (the circuit 13). When a service machine is moved into a dangerous area, then a limit switch is tuned ON, and so the respective solenoid valves 9, 10, 16 are worked from positions (b) to positions (a), and the circuit 3 onto a boom and the circuit 13 of the offset cylinder 12 is also interrupted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine interference prevention device for preventing a work machine from interfering with a driver's cab at the time of working on a vehicle for excavation and loading such as a power shovel.

[0002]

2. Description of the Related Art In an excavating and loading vehicle such as a power shovel, a working machine including a boom, an arm and a bucket is generally provided on an upper revolving structure. At the time of work, the boom undulates with respect to the upper revolving structure, and the arm provided at the tip of the boom and the bucket at the tip thereof rotate in the front-rear direction. It does not interfere with the cab at the top of the body. However, when excavating the side of the vehicle, it cannot be excavated by the above-mentioned working machine, so the conventional boom is divided into upper and lower parts and the upper boom is rotated in the left-right direction with respect to the lower boom. There is one that is pin-coupled so that it can be moved to allow gutter digging. In an excavating and loading vehicle having such a mechanism, when the upper boom is offset toward the cab side,
There is a risk that the working range of the arm and bucket will interfere with the cab. Therefore, in order to prevent such interference, it is considered to automatically stop the work when entering the interference area.When the automatic stop is applied, the whole operation, that is, the boom up / down, -It was supposed that digging and dumping, bucket digging and dumping, turning left and right, and offset right and left were symmetrical. As a specific structure of the automatic stop, as shown in FIG. 4, a lock solenoid valve 43 for pilot pressure control, which is connected by a controller 41 and an electric circuit 42, respectively.
And the offset lock solenoid valve 44 is used for automatic stop. For example, when the operation of the offset cylinder 45 is stopped, the hydraulic circuit 48 connected from the pump 46 via the direction switching valve 47 is provided. The offset lock solenoid valve 44 is provided. In this structure, when the working machine enters the area where the working machine interferes with the operator cab, the controller 41 detects this and switches the offset lock solenoid valve 44 from open to closed to shut off the hydraulic pressure from the pump 46. Thus, the movement of the offset cylinder 45 is stopped. The lock is released by the operator pushing a release button provided on the work machine operation knob. The same applies to the lock solenoid valve 43 for pilot pressure control.

[0003]

However, the above interference prevention device has the following problems. That is, in the example of FIG. 4, when the hydraulic pressure is supplied to the left side of the offset cylinder 45, the circuit 48 is cut off by the lock. Therefore, when the lock release button is pressed, the circuit 48 is connected again. Then, there is a risk that the offset cylinder 45 may move toward the dangerous area. Also, the release button has to be pressed each time it is released, which is troublesome.

In view of the above, the present invention has a symmetric operation for automatically stopping only on the boom, arm excavation, and the dangerous side area on the left of the offset, and the operation and turning operation in the safe side area after automatic stop are possible. The work machine interference prevention device described above is provided for the purpose of solving the drawbacks of the prior art.

[0005]

As a means for solving the above-mentioned problems of the prior art, the present invention mounts a working machine on the front side of the operator's cab so that it can perform bending work motion toward the operator's cab. In a vehicle for excavation and loading, according to claim 1, among hydraulic circuits from a directional control valve for booms to a boom cylinder, a circuit on the raising side and from the directional control valve for arms to an arm cylinder. In the hydraulic circuit, first and second solenoid valves are provided in the middle of the circuit on the excavation side to shut off the circuit by limit switches, respectively, and the rod of the offset cylinder in the circuit from the directional switching valve for offset to the offset cylinder is provided. A third circuit is provided with a pilot check valve in the circuit extending to the side, and the limit switch shuts off the oil supply to the rod side.
The present invention is characterized in that the pump is connected to a solenoid valve, and the downstream side of the boom raising pressure switch and the arm excavating pressure switch connected in series is connected to the pump when the both switches are ON. Is connected to a pilot pressure control lock solenoid valve that operates to lock, and an offset lock solenoid valve is provided in the circuit from the directional switching valve of the offset cylinder to the offset cylinder. In the third aspect of the present invention, the boom raising pressure switch, the arm excavation pressure switch and the offset left pressure switch are connected in series. Pilot pressure control from the pump when all of the switches are on the downstream side Characterized in that linked to the pilot pressure control lock solenoid valve which operates the circuit in the lock leading to.

[0006]

With the above construction, in accordance with the first aspect of the present invention, the limit switch is actuated to lock the boom excavation circuit and the bucket excavation circuit, and the pilot check valve locks the left side of the offset cylinder to prevent interference.
In the second aspect of the present invention, when the boom raising pressure switch and the arm excavating pressure switch are turned ON, the pilot pressure control lock solenoid valve shuts off the circuit to the pilot pressure control valve, and the offset limit switch is turned ON to perform the offset lock. The solenoid valve operates to cut off the oil supply to the offset cylinder, thus preventing interference. In claim 3, O of all of the boom raising pressure switch, the arm excavation pressure switch and the offset left pressure switch.
Since the circuit from the pump to the pilot pressure control valve is shut off by the pilot pressure control lock solenoid valve by N, interference is prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a first embodiment of the present invention, FIG. 2 is a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention. It is a circuit diagram. Hereinafter, the same parts shown in FIGS. 1 to 3 will be described with the same reference numerals.

The present invention relates to a vehicle for excavation and loading (not shown) in which a working machine is mounted on the front side of a driver's cab so as to be able to perform a bending work motion toward the driver's cab. Claim 1 is shown in FIG. From the directional control valve 1 for the boom
Among the hydraulic circuits 3 and 4 reaching the cylinder 2, the hydraulic circuit 7 on the raising side and the hydraulic circuits 7 and 8 reaching the arm cylinder 6 from the directional switching valve 5 for the arm are in the middle of the circuit 7 on the excavating side. The limit switches (not shown) make the circuit 3,
The first and second solenoid valves 9 and 10 for shutting off 7 are provided, and among the circuits 13 and 14 from the directional switching valve 11 for offset to the offset cylinder 12, the circuit 13 to the rod side of the offset cylinder 12 is A pilot check valve 15 is provided, and the check valve 15 is connected to a third solenoid valve 16 that shuts off the oil supply to the rod side (circuit 13) by the limit switch. In the figure, 17 is a pump.

It is turned on when a driver's cab and a working machine (not shown) approach each other and enter a dangerous area where they may interfere with each other.
Is provided with a first solenoid valve 9, a second solenoid valve 10 and a third solenoid valve 15 which have two positions a and b, respectively, and are connected to the limit switch by an electric circuit 18. As a result, when the working machine enters the dangerous area, the limit switch is turned on, so that each solenoid valve 9, 10, 16 b
From the position to the a position, the circuit 3 for the boom and the circuit 7 for the arm excavation are shut off, and the rod side circuit 13 of the offset cylinder 12 is also shut off by the check valve 15.
When the working machine enters the safe area where there is no risk of interference from the dangerous area, the limit switch is turned off, so that each solenoid valve 9, 10, 16 is returned to the original position b and the lock is released.

According to a second aspect of the present invention, as shown in FIG. 2, a pump 22 is provided downstream of the boom raising pressure switch 20 and the arm excavating pressure switch 21 when both switches 20 and 21 are ON. The circuit 24 from the pilot pressure control valve 23 to the pilot pressure control valve 23 is connected to the pilot pressure control lock solenoid valve 25 that operates to lock, and the direction switching valve 11 of the offset cylinder 12 to the offset cylinder 12 is connected.
An offset lock solenoid valve 26 is provided in each of the circuits 13 and 14 leading to the offset lock solenoid valve 26.
Is configured so that both the signal of the controller 27 and the offset limit switch 28 can be locked. In the figure, 29 is a battery, 34
Is an electric circuit.

The boom raising pressure switch 20 and the arm excavating pressure switch 21 are both limit switches and are provided between a driver's cab (not shown) and a working machine, and the working machine approaches and interferes with the operator's cab. It is connected via an electric circuit 34 to a pilot pressure control lock solenoid valve 25 having a and b2 positions so that each of them is turned on when entering a dangerous danger area where there is a risk of the occurrence of the above. Also, a,
Offset lock solenoid valve 26 having b2 position
Operates on in the safe area but off in the dangerous area
An electric circuit 35 is connected to the controller 27 and the offset limit switch 28 so as to be switched to the lock side (position b) by the offset limit switch 28 and the controller 27 that operate in the above manner. Therefore, the switches 20 and 21 are turned on and the limit switch 28 is turned on.
Is off, all are locked, and when the safe area is entered from the dangerous area, the boom raising pressure switch 20 and the arm excavating pressure switch 21 are turned off, so that the electric circuit 34 is disconnected and the pilot pressure control lock is performed. The solenoid valve 25 is switched to the b position and unlocked. Also,
The offset limit switch 28 is turned on and a
It is switched to the position and the lock is released.

According to a third aspect of the present invention, as shown in FIG. 3, a boom raising pressure switch 20, an arm excavating pressure switch 21 and an offset left pressure switch 30 are connected in series, and all the switches are turned on at the downstream side thereof. At this time, a circuit 24 from the pump 22 to the pilot pressure control valve 23 is connected to a pilot pressure control lock solenoid valve 25 that operates to lock.

The boom raising pressure switch 20, the arm excavation pressure switch 21 and the offset left pressure switch 30 are all limit switches, which are provided between a driver's cab (not shown) and a working machine, and the working machine is operated. The electric circuit 3 is turned on when it enters the dangerous area where there is a possibility of interference by approaching the chamber, and the circuit 24 can be locked by switching the pilot pressure control lock solenoid valve 25 from the b position to the a position.
It is connected to 1. Therefore, all the switches are ON
When activated, the electric circuit 31 is energized to switch the pilot pressure control lock solenoid valve 25 to the a position, and the pump 2
The circuit 24 from 2 to the pilot pressure control valve 23 is locked. And even one of the above switches is OFF
Then, the safety zone is entered, and the pilot pressure control lock solenoid valve 25 is switched to the a position and the lock is released.

[0014]

As described above, according to the present invention, only the dangerous operation (boom up / arm excavation / offset left) is the target operation to be automatically stopped, and after the automatic stop, the safe operation (boom) is performed. -Under-arm, arm dump, bucket excavation, dump) and turning operations are possible, so there is no need to automatically lock all operations as in the past, and the lock is automatically released, so the structure is extremely simple. become.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an embodiment of a work implement interference prevention device according to claim 1 of the present invention.

FIG. 2 is an explanatory diagram of an embodiment of a work implement interference prevention device according to claim 2 of the present invention.

FIG. 3 is an explanatory diagram of an embodiment of a work implement interference prevention device according to claim 3 of the present invention.

FIG. 4 is an explanatory diagram showing an example of a conventional work machine interference prevention device.

[Explanation of symbols]

1-way switching valve 2 boom cylinders 3,4 hydraulic circuit 5 directional valve 6 arm cylinder 7,8 hydraulic circuit 9 First solenoid valve 10 Second 〃 11 Directional switching valve 12 offset cylinder 13, 14 Hydraulic circuit 15 Pilot check valve 16 Third solenoid valve 20 boom pressure switch 21 Arm drilling pressure switch 22 pumps 23 Pilot pressure control valve 24 circuits 25 Solenoid valve for pilot pressure control 26 Offset lock solenoid valve 27 Controller 28 Offset limit switch 30 offset left pressure switch

Claims (3)

[Claims] 1. A vehicle for excavation and loading, in which a working machine is offset to the front side of a driver's cab so as to be able to perform a bending work motion toward the driver's cab, in which a directional selector valve for a boom is installed. Of the hydraulic circuit reaching the cylinder, the circuit on the raising side and the hydraulic circuit from the directional switching valve for the arm to the arm cylinder are cut off by limit switches in the middle of the circuit on the excavating side. , A second solenoid valve is provided, and a pilot check valve is provided in the circuit from the direction switching valve for offset to the offset cylinder to the rod side of the offset cylinder, and this check valve is provided on the rod side by the limit switch. A work machine interference prevention device, characterized in that the work machine interference prevention device is connected to a third solenoid valve that shuts off the oil supply to 2. A boom raising pressure switch connected in series in a vehicle for excavation and loading, in which a working machine is offset to a front side of a driver's cab and mounted so as to perform a bending work motion toward the driver's cab. Downstream of the arm excavation pressure switch is connected to a pilot pressure control lock solenoid valve that operates to lock the circuit from the pump to the pilot pressure control valve when both switches are ON, and the direction of the offset cylinder is switched. An offset lock solenoid valve is provided in the circuit from the valve to the offset cylinder, and this offset lock solenoid valve is operated to lock both the signal of the controller and the offset limit switch. apparatus. 3. An excavation and loading vehicle in which a working machine is offset to the front side of a driver's cab so as to be able to perform a bending work motion toward the driver's cab, in a boom raising pressure switch and an arm excavator. The pressure switch and the offset left pressure switch are connected in series, and all the switches are connected to the downstream side of the O switch.
A work machine interference prevention device characterized in that, when N, a circuit from the pump to the pilot pressure control valve is connected to a pilot pressure control lock solenoid valve that operates to lock.