JPH0236409B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention involves holding the locking pin between a holding piece that receives the locking pin at the bottom of the sliding door and a hook, and in this state, moving the sliding door downward around the locking pin. When
This dump truck prevents the hook from disengaging from the locking pin due to the impact, and also prevents the door from falling even when the cargo box is dumped with the door moved downward. This invention relates to a safety device in a sliding door opening/closing device. In the conventional fan door opening/closing device shown in FIG. 7, that is, in the fan door opening/closing device in which a buffer cylinder 03 with a spring inside is provided in the middle of the rod 02 between the operating arm (not shown) and the hook 01, the fan door opening/closing device is If you remove the upper hinge part and move the fan door 04 downwards around the lower locking pin 05, the fan door 04 will move to the floor plate 0 due to its own weight.
6 violently collides with the lower end of the sliding door 04, a moment acts on the lower part of the sliding door 04 centering on the collision part 07, and a large force acts on the hook 01 in the opening direction.

At this time, the spring in the buffer cylinder 03 is compressed by the acting force, the distance between the operating arm and the hook 01 is lengthened, and the hook 01 is rotated to the opening side, and the hook 01 is released from the locking pin 05. This causes the fan door 04 to fall.

If the fan door 04 were to fall onto the worker's feet in the above state, a serious accident would occur.

Furthermore, when the floor plate 06 of the cargo box is dumped as shown in FIG. 8 while the sliding door 04 is moved downward, the hook 01 rotates as the cargo box rises, and the locking pin 05 and the hook 01 Since the engagement is disengaged, the fan door is 0.
4 falls due to its own weight, so it is necessary to lift the heavy fan door again and install it.

The present invention solves the above problem, and embodiments thereof will be described below with reference to the drawings.

Reference numeral 1 denotes a cargo box that tilts rearward around a hinge portion 3 at the rear end of the chassis frame 2, and 4 a sliding door that swings around a removable upper hinge 5 provided at the upper rear end of the cargo box 1. At the bottom of this sliding door 4, a locking pin 8 that engages a hook 7 is fitted into a holding piece 6 provided on the rear surface of the bottom of the cargo box 4, and a pair of left and right mounting pieces 9, 9' are fitted. The holding piece 6, hook 7, and locking pin 8 constitute a lower hinge 10.

The holding piece 6 is formed with a fitting hole 11 that opens rearward, and the lower surface of the fitting hole 11 is approximately horizontal.
The top surface slopes upwards and backwards. The hook 7 is pivotably supported 12 at the rear end of the bottom of the cargo box 1, and the tip of the hook 7 is disposed on the one mounting plate 9' side with the holding piece 6 as a border. .

Reference numeral 13 designates an operating arm 14 which is attached to the bottom of the cargo box 1 in front of the hook 7 so as to be able to swing back and forth.The operating arm 14 and the hook 7 are connected to each other by a rod 17 via a buffer tube 16 inside a spring 15. ing.

A guide piece 18 guides the roller 19 at the tip of the operating arm 13, and is attached to the chassis frame 2 side.

Incidentally, 20 is a spring connected to the rod 17 side and the cargo box 1 side to spring the rod 17 backward.

However, when the cargo box is raised, the operating arm 13
Since the roller 19 at the tip is separated from the guide piece 18, the rod 17 is pulled backward by the force of the spring 20, and the hook 7 and the locking pin 8 are disengaged, and the sliding door 4 is released from the upper hinge 5. The swing door 4 is opened by swinging backwards at the center.

On the other hand, if the locking pin 8 is held between the holding piece 6 and the hook 7 and the upper hinge 5 of the fan door 4 is removed in this state, the fan door 4 will move downward around the lower hinge 10, and the fan door will move downward. It will be released.

Next, to explain the main parts of the present invention, in the normal state shown in FIG.
A protrusion 21 is formed on its upper surface with a circular arc surface of approximately 180 degrees centered on the axis of the protrusion 21 . Further, a stopper member 22 such as a stopper pin is horizontally drilled on the side surface of the holding piece 6 below the opening of the fitting hole 11 at a position corresponding to the protrusion 21 .

In addition, the position of stopper members such as stopper pins is as follows:
When the fan door 4 is moved downward by 50 degrees to 180 degrees, the protrusion 21 comes close to a stopper member 22 such as a stopper pin, and when the locking pin 8 is further moved to the rear of the opening side, the protrusion 21 It engages with a stopper member 22 such as a stopper pin to prevent the locking pin 8 from falling off. Now, with the locking pin 8 being held between the holding piece 6 and the hook 7, if you remove the upper hinge 5 and move the fan door 4 downward, the fan door 4 will rotate approximately 180 degrees. As shown in Figure 4, it collides with the end of the floorboard that makes up the cargo box 1.

At this time, the attachment portion of the locking pin 8 is attached to the protrusion 23.
A moment acts in the clockwise direction around , and this force acts on the tip of the hook 7 as a large force.

When the acting force is generated, the spring 15 in the buffer cylinder 16 is compressed to lengthen the distance between the operating arm 13 and the hook 7, so that the hook 7 is rotated in a direction to disengage from the locking pin 8. However, when the fan door 4 moves downward approximately 180 degrees, the protrusion 21 engages with the stopper member 22 such as the stopper pin of the holding piece 6, so the locking pin 8 cannot be removed from the fitting hole 11. This prevents the sliding door 4 from falling.

If the sliding door 4 is moved downward around the lower hinge 10 and the cargo box 1 is dumped in this state, the hook 7 will be rotated in the opening direction as shown in FIG. Since the protrusion 21 and the stopper member 22 such as a stopper pin are engaged,
The locking pin 8 does not come off from the fitting hole 11, and even if the cargo box 1 is dumped significantly, the surface of the protrusion 21 is arcuate, so that the protrusion 21 and the stopper member 22 such as a stopper pin do not come off. The engagement state of the door 4 remains unchanged, thereby reliably preventing the sliding door 4 from falling.

In the above embodiment, the protrusion is provided on the upper surface of the locking pin, but the protrusion is provided at the lower part of the locking pin, and a stopper member such as a stopper pin is provided at the upper part of the opening of the fitting hole. However, the object of the present invention can be achieved. Furthermore, although the protrusion is provided on the surface of the locking pin, the protrusion may be attached to the side surface of the mounting piece 9 that supports the locking pin.

As described above, the present invention provides a protrusion on the side of the locking pin provided at the lower part of the sliding door, and provides a stopper member such as a stopper pin on the holding piece that receives the locking pin,
When the sliding door is moved downward, the protrusion engages with a stopper member such as a stopper pin, so the locking pin does not come out of the fitting hole, thereby ensuring that the sliding door does not fall. It can be prevented.

[Brief explanation of drawings]

Figure 1 is a sectional view showing the overall view of a fan door opening/closing device equipped with the device of the present invention, Figures 2, 3, and 4.
5 and 6 show the engagement relationship between the protrusion of the present invention and a stopper member such as a stopper pin, and FIG. 2 is a sectional view when the opening of the cargo box is closed with a sliding door. Fig. 3 is a rear view of Fig. 2, Fig. 4 is a sectional view when the sliding door is moved downward, Fig. 5 is a partial perspective view of Fig. 2, and Fig. 6 is a rear view of the sliding door when it is moved downward. 7 and 8 are cross-sectional views showing a conventional sliding door opening/closing device. 4 is a fan door, 5 is an upper hinge, 6 is a holding piece, 8 is a locking pin, 10 is a lower hinge, 11 is a fitting hole, 2
1 is a projection, and 22 is a stopper member such as a stopper pin.

Claims (1)

[Claims] 1 Move the sliding door upwards around the upper hinge,
In addition, in a dump truck door opening/closing device in which the door can be moved downward around the lower hinge, a locking pin is provided at the bottom of the door, and the locking pin is provided on the cargo box side. A holding piece is provided with a fitting hole that can be received, and a substantially semicircular arc-shaped protrusion is provided on the locking pin side that protrudes from the locking pin surface when the sliding door is stored vertically. A stopper member corresponding to the protrusion is provided on the holding piece adjacent to the opening of the fitting hole, and when the door is moved downward around the lower part, the protrusion and the stopper member protrude. A safety device for a swing door opening/closing device for a dump truck, wherein the locking pin is engaged with a stopper member to prevent the locking pin from coming out of the fitting hole.