JPS582084B2 - Dump truck - Google Patents

Description

[Detailed Description of the Invention] The present invention is designed to automatically open and close the rear fan door of a dump truck, etc. in connection with the dumping operation, and to maintain it in a closed state regardless of the dumping operation from the driver's cabin. This invention relates to an operable fan door opening/closing device.

General dump trucks are equipped with a so-called automatic opening/closing device that opens or locks the rear fan door in conjunction with the operation of dumping cargo boxes. It is necessary to dump the vehicle while it is tied down, and for this purpose, a manual opening/closing device is often provided in addition to the automatic opening/closing device.

Conventionally, the above-mentioned manual opening/closing device generally has a structure in which a cargo box is equipped with a link mechanism lashing device that is operated by the driver each time after leaving the driver's cab.

However, it is extremely troublesome for the driver to leave the driver's cab each time an operation is to be performed, and there is a demand for a structure that allows all operations to be performed from within the driver's cab.

In order to satisfy these demands, the present invention provides a device that allows the operation part of a manual opening/closing device to be easily introduced into the driver's cab using an electric cord, and is designed to be easy to operate and prevent erroneous operation. It is.

The following embodiments will be explained with reference to the drawings. 1 is a driver's cab of a dump truck, 2 is a cargo box mounted on a car body via a subframe 3, and the rear part is pivoted to the subframe 3 by a hinge pin 4. .

Reference numeral 5 denotes a sliding door which can be rotated by pivoting (not shown) at the upper rear end of the cargo box 2, and a horizontal shaft 7 is provided at the lower end to engage with a lashing pawl 6 at the rear end of the bottom of the cargo box. There is.

One end of a transmission link 8 is connected to the base end of the lashing claw 6, which allows the lashing claw 6 to move up and down, and which does not rotate outward by a dead point method when the lashing claw is engaged. It is connected to the tip of a transmission rod 11 whose other end is connected to a histone rod 10 of the air chamber device 9.

An actuating piece 13 for switching a switch 12, which will be described later, is fixed on the transmission rod 11, and a return spring 15 is provided between the actuating piece 13 and a contact member 14 fixed to the cargo box side to return the lashing pawl 6 to the closed position. is provided.

The piston rod 10 is separated by a diaphragm 19 from a chamber 18 with which an air pipe 17 from an air tank 16 mounted on the vehicle body communicates.
A spring 21 is provided which passes through the chamber 20 on the opposite side partitioned by and acts in the direction of the chamber 18.

A pressure regulating valve 22 is attached to the air tank 16 to prevent the internal pressure of the tank from falling below a certain value, and the air pipe 17
is provided with a pressure regulating valve 22 and a solenoid valve (electromagnetic valve) 23, and communicates with the air chamber device 9 via the hinge pin 4 portion of the cargo box 2.

The solenoid valve 23 opens and closes the passage of the air pipe 17 by disconnecting and disconnecting current, and a cord 25 from a DC power source 24 is connected to the solenoid valve 23, with a limit switch 26 and a hand switch 27 interposed therebetween. It's connected.

The limit switch 26 is fixed to the subframe 3 so that it comes into contact with the cargo box 2 when the cargo box 2 is in the lowered state, and separates when the cargo box 2 is in the dumped state.
7 is provided in the driver's cab 1, and the cord 25 is appropriately wired via these devices.

28 is a relay device that is installed in parallel with the hand switch 27 to self-hold the hand switch 27, and the relay cord 29
is the switch 1 that is turned on and off by the operation of the chamber device 9.
2, and the cord 30 coming out from the switch 12 is connected to the DC power source 24 via the hinge pin 4 portion of the cargo box.

Reference numeral 31 denotes a pilot lamp provided on a cord 32 branched from the relay cord 29, and the open/closed state of the lashing claw 6 can be known in the driver's cab 1 by blinking the pilot lamp 31.

The structure of the present invention is as described above, and the operation will be explained next.

When the cargo box 2 is in the lowered storage position, the limit switch 26, solenoid valve 23, and relay device 28 are always activated.
is in a state of discontinuation.

Now, if the sliding door 5 is to be automatically opened and closed in relation to the ups and downs of the cargo box 2, the hand switch 27 is operated directly.

Even with this operation, if the cargo box 2 is in the storage position, no current flows through the cord, and the lashing claws 6 remain in the closed state.

Therefore, when the cargo box 2 is dumped, the limit switch 26 which has been pressed by the cargo box 2 until now is released, switches upward from the position shown in FIG. The air flows through the solenoid valve 23, the solenoid valve 23 switches downward from the position shown in FIG.
Compressed air flows into the chamber 18 from the air tank 16, pushes the piston rod 10 to the right together with the diaphragm 19, rotates the lashing claw 6 upward via the transmission rod 11 and the transmission link 8, and stirs the piston rod. The lashing of door 5 is released.

During the above operation, as the transmission rod 11 moves, the actuating piece 1
3 also moves to the right to connect the switch 12, current also flows through the relay cord 29, the relay device 28 is connected, and the current also flows through the cord parallel to the hand switch 27.

Therefore, in this dumped state, even if the hand switch 27 is accidentally turned off, current continues to flow through the solenoid valve 23 and the lashing claw 6 remains open.

In the above case, if the relay device 28 is not installed, if the hand switch 27 is turned off by mistake, the lashing claw 6
moves downward and cannot engage with the horizontal shaft 7 when the cargo box is stored.

From the above, it can be seen that when the cargo box 2 is dumped, the lashing claw 6 always operates to the open side.

Also, when the packing box 2 is returned to the storage position, the limit switch 2
6 is switched to disconnection, and current no longer flows through cord 25.
The solenoid valve 23 is also switched off.

Therefore, the compressed air in the chamber 18 of the air chamber device 9 is released to the atmosphere, the piston rod 10 is retracted by the action of the spring 21 and the return spring 15, the lashing claw 6 moves downward, and the horizontal axis of the fan door 5 17.

At this time, the actuating piece 13 comes off from the switch 12 and is disconnected, so that no current flows through the relay cord 29, and the relay device 28 is disconnected.

Next, when manually opening and closing the fan door 5, if you turn off the hand switch 27, even if the load box 2 is dumped and the limit switch 26 is connected, the cord 25 will not be current. does not flow, and the lashing claws 6 keep the fan door 5 closed.

In the above-mentioned dumped state, operations such as draining the loaded object can be performed, and if necessary, by bringing the hand stopper 27 into contact, the solenoid valve 23 is brought into contact, and compressed air is supplied to the air chamber device 9. The loaded object can be discharged by rotating the lashing claw 6 upward and opening the fan door 5.

Further, since the pilot lamp 31 lights up when the lashing claw 6 is opened and current flows through the relay cord 29, the open/closed state of the lashing claw 6 in each operation can be confirmed in the driver's cab 1.

As described above, the present invention has a structure in which the air chamber device is operated by simply leading a cord into the operator's cab and turning on and off the current, so that the structure and operation are very simple.

In addition, since a relay device is installed in parallel with the hand switch, when the lashing claw is closed, it is always engaged with the horizontal axis of the fan door, and the loaded object can be driven without lashing the fan door. There is no need to worry about it scattering.

[Brief explanation of the drawing]

1 and 2 are schematic diagrams of hoses, cords, and various devices installed in a dump truck, with FIG. 1 showing the front half of the dump truck, and FIG. 2 showing the rear half of the dump truck. Figure 3 is a piping and wiring diagram. In the figure, 1 is the driver's cabin,
2 is a packing box, 3 is a subframe, 5 is a fan door, 6 is a lashing claw,
9 is an air chamber device, 12 is a switch, 13 is an operating piece, 16 is an air tank, 17 is an air pipe, 23 is a solenoid valve, 25 is a cord, 26 is a limit switch, 27 is a hand switch, 28 is a relay device, 29 is The relay code 31 is a pilot lamp.

Claims (1)

[Claims] 1 Connect the lashing claws that secure the fan door and the air chamber device to a transmission means such as a rod, connect the air chamber device and the air source with an air pipe, and insert a solenoid valve in the middle of the air pipe. In a device that opens and closes the fan door by switching the solenoid valve, a hand switch that can be operated in the operator's cabin and a limit switch that operates in connection with the dumping operation of the cargo box are connected in series in the cord. A relay device is installed in parallel to the hand switch, and the hand switch is held in place by the operation of a switch that is switched in conjunction with the operation of the air chamber device. A fan door opening/closing device for a dump truck, etc. that controls energization.