JPS5934532B2 - Dump truck control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an operation control device for a dump truck that can appropriately operate the on/off operation of a power take-off device and the switching operation of a valve for raising and lowering a cargo box using a single operation lever. It is.

Recently, a control device using a single lever has been adopted for the connection/disconnection operation of a power take-off device and the switching operation of a valve for lifting and lowering a cargo box due to its simple structure and operation.

However, in the case of the conventional control device using a single lever, as is clear from Fig. 1, when switching the cargo box lifting valve from the lower position to the upper position, the power is applied when the valve is in the mid-normal position. The take-out device maintains the disconnection through a long hole in the middle of the transmission member, and when the valve for lifting the cargo box is switched from the upper position to the lower position, the power take-out device is in contact with the long hole when the valve is in the normal position. The state will be maintained.

Therefore, for example, in so-called gravel spreading work, in which the valve is switched to the upper position to raise the cargo box to an appropriate height, and then the valve is switched to the mid-center position to stop the cargo box midway, and the vehicle is driven in that state, In addition to being used for traveling, the power is also used to drive the unnecessary power take-off device and hydraulic pump, which also causes early wear and tear of the power take-off device and hydraulic pump.

In view of the above-mentioned points, the present invention provides a control device for a dump truck in which, when the valve is switched from the upper position to the lower position, the power take-off device can be switched off at an intermediate position in the middle.

An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 denotes a power extraction device for extracting power from a transmission for an automobile, and it is connected and disconnected by operating a shifter 2 back and forth.

Reference numeral 3 indicates a hydraulic pump, and this hydraulic pump 3 is driven by a drive shaft 4 connected to the power extraction device 1.

Reference numeral 5 designates a valve for lifting and lowering the cargo box, which guides the oil discharged from the hydraulic pump 3 to the hydraulic cylinder 6 to control the lifting of the cargo box, as well as controlling the lowering and stopping of the cargo box. 1 shows an operating lever that can control the connection and disconnection of the power extraction device 1 and the disconnection of the valve 5 for lifting and lowering the cargo box, and the other end of the operating lever 7 is connected to the first bell crank 8. One end of the push-pull wire 9 is connected.

The valve 5 is connected to one side of the first bell crank 8 by a transmission member 11 such as a transmission rod with a second bell crank 10 interposed therebetween, and the other side of the first bell crank 8 will be described later. A shifter 2 of a power take-off device 1 is connected to the transmission member 13 via a link mechanism 12.

Next, the link mechanism 12 described above will be explained with reference to FIGS. The member 13 is connected to the swing piece 14, and the other end of a link member 17 having a bent portion 16, one end of which is connected to the shifter 2 of the power take-off device 1, is pivotally supported approximately in the middle of the swing piece 14.

The link member 17 has a first link 18 that has one end connected to the power take-off device 1 side, and a second link 18 that has one end connected to the swing piece 14 side.
The bending portion 16 between the first link 18 and the second link 19 is prevented from being bent by a predetermined angle α or more by a stopper 20 provided at the end of the second link 19.5.
Furthermore, a guide roller 22 that rolls on the upper end surface of the guide piece 21 is pivotally supported on the bending portion 16 .

By the way, when the swinging piece 14 is rotated to the position indicated by the two-dot chain line in FIG. When the valve is rotated to the position shown by the solid line in FIG. 4 immediately after it is released, the power take-off device 1 is switched to the disconnected position, and the valve 5 is switched to the neutral position.
Furthermore, when the swinging piece 14 is rotated to the solid line position in FIG. 3 where the bending portion 16 is freely bendable, the bulb 5 is switched to the lower position.

The present invention has the above-described configuration, and is now in the state shown in FIG. 2 where the valve 5 is switched to the down position and the power take-off device 1 is switched off, that is, the operating lever 7 is switched to the position A. When the operating lever 7 is moved to the mouth position, the first
The bell crank 8 is swung counterclockwise, and one transmission member 11 connected to the first bell crank 8 thereby
is pushed rearward and the valve 5 is switched to the neutral position.

On the other hand, the other transmission member 13 connected to the first bell crank 8 is pulled rearward, and the swinging piece 14 is moved to the second position shown in FIG.
It will be moved to the position indicated by the dotted chain line.

In this case, since the link member 17 whose one end is connected to the shifter 2 of the power extraction device 1 is bendable, the force for moving the shifter 2 is not transmitted, and the power extraction device 1 remains disconnected.

When the operating lever 7 is further operated to the position, the valve 5 is switched to the upper position in the same manner as described above, and one of the swinging pieces 14 is moved to the upper position.
is rotated to the position indicated by the two-dot chain line in FIG. Since the force of the operating lever 7 is regulated, the force of the operating lever 7 is transmitted to the shifter 2 via the link member 17, so the power take-off device 1 is switched to the contact state.

In the above state, the hydraulic pump 3 is driven by the power from the power extraction device 1, and the oil discharged from the hydraulic pump 3 flows into the hydraulic cylinder 6 through the valve 5 to extend the hydraulic cylinder 6 and release the load. Raise the box.

Next, when the operating lever 7 is operated to the C position, the valve 5 is again switched to the neutral position and the lifting of the cargo box is stopped.

On the other hand, the swinging piece 14 moves to the solid line position in FIG.
2 rolls on the guide piece 21, the bending angle of the bending part 6 is kept constant, and the rotation of the swinging piece 14 is controlled by the link member 17.
The power is transmitted to the shifter 2 via the switch 2, whereby the power take-off device 1 is switched off and the drive of the hydraulic pump 3 is stopped.

Further, when the operating lever 7 is switched to the A position, the valve 5 is switched to the lower position E, and the swinging piece 14 is moved to the solid line position in FIG. 3.

At this time, since the bending portion 16 is free to bend in a direction that reduces the bending angle, the force from the operating lever 7 is not transmitted to the shifter 2, and the bending portion 16 remains in the bent state.

By the way, in so-called gravel spreading work in which the cargo box is run with the cargo box raised to an appropriate height, the power extraction device 1 is switched to off, so the hydraulic pump 3 is not driven.

With the present invention as described above, the power extraction device is switched off during gravel spreading work in which the cargo box is driven in an elevated state, so that the power of the automobile is used only for driving. This reduces power consumption and eliminates unnecessary driving of hydraulic pumps, which extends the lifespan of oil field pumps and makes them extremely convenient.

[Brief explanation of drawings]

Fig. 1 is an operation system diagram showing a conventional dump truck control device, Fig. 2 is an operation system diagram of the device of the present invention, and Figs. 3 and 4 are partially enlarged front views showing the main parts of Fig. 2. . In the figure, 1 is a power take-off device, 5 is a valve, 7 is an operating lever, ICl3 is a transmission member, 14 is a rocking piece, 16 is a bending part, 17 is a link member, 20 is a stopper, and 21 is a guide piece. .

Claims (1)

[Claims] 1. In a control device for a dump truck that operates a power take-off device and a valve for lifting and lowering a cargo box using a single operating lever, a swinging piece that swings in conjunction with the operation of the operating lever, and one end of which is connected to the swinging piece. a link having a transmission member that is connected to the transmission member and whose other end is connected to a valve for lifting and lowering a cargo box; and a link that has a bending part in the middle, one end of which is connected to a power take-off device, and the other end of which is pivotally supported by the swinging piece. The bending part has at least a member, and the bending part is regulated from bending beyond a predetermined angle by a stopper attached to the link member, and further, when the bending part reaches a predetermined angle, the bending part is guided by a guide piece. An operation control device for a dump truck that swings back and forth and maintains the angle of the bending part at a constant angle.