JPS646055B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention and Prior Art The present invention relates to an opening/closing device for the rear door of a dump truck that is simple, reliable, and economical. The applicant previously filed utility model registration application no.
Although we have provided several rear door opening/closing devices, including No. 111640, we have developed an extremely simple device with great effects, so we are providing it here again.

Normally, the rear door of a dump truck is rotatably attached to both the left and right edges of the loading platform, and the key is released by the activation of a device that occurs when the loading platform rises during cargo dumping, and by the pressing force of the cargo. The rear door can now be opened. Therefore, if the cargo is gravel or sand, there is no particular problem in unloading the cargo, but if the cargo is larger than the height of the loading platform, i.e., the height of the rear door, such as large stones, large tree roots, or waste materials, These cargoes get stuck on the top of the rear door, making dumping difficult. If you forcefully try to dump the cargo in such a case, you will not only damage the rear door, but also damage the rear door due to the collision of the cargo, and the front of the vehicle will stand on end due to the load, causing the vehicle to fall over. It even poses a danger. Especially when the dump site is on a high road side, it is not uncommon for the vehicle to fall onto the road, and this type of accident is a constant occurrence. Therefore, in order to prevent such damage to the vehicle body and accidents, it may be necessary to remove the rear door beforehand before dumping, which results in a decrease in the efficiency of the dumping operation.

The applicant intends to provide a dump truck that prevents the above-mentioned dangers, eliminates damage to the vehicle body, and can be expected to improve dumping efficiency.

Embodiments of the present invention will be described below with reference to the drawings.

(2) Regarding the Structure of the Invention FIG. 1 is a first embodiment, which is a partial side view of a dump truck having a rear door opening/closing device of the present invention, and is an explanatory diagram showing its open/closed state.

In the figure, a guide plate 11 having a slide groove 10 of an appropriate length is attached to the rear upper edge of a dump truck bed side plate 12, and a support shaft hole 4' is formed in the rear end of the guide plate 11. ing. The tip of the rotary arm 2 is connected to the slide shaft 6 in the slide groove 10.
The rear door 1 is rotatably and pivotally connected to the rear end of the rotary arm 2 via a rotary shaft 5. One end of a support arm 3 is pivotally attached to the support shaft hole 4' of the guide plate 11 via a support shaft 4 so as to be able to rise and fall. It is pivotally connected by a support shaft 7 to a support shaft hole 7' provided in the section.

At this time, the length of the slide groove 10 is the same as that of the slide shaft 6.
It is necessary to set the distance between the rear door 1 and the support shaft 7 to be the same or longer, and the position of the support shaft 7, the length of the support arm 3, the length of the rotating arm 2, etc. when the rear door 1 is closed. It goes without saying that it should always be set in close contact with the rear edge of the carrier frame.

Incidentally, as shown in FIG. 2, the support arm 3 may be constituted by a support plate 3'.

The present invention has the above-mentioned configuration, and its effects will now be described.

(3) Regarding the operation and effects of the invention When the loading platform 17 is raised when dumping the cargo 8, the catch 13 of the rear door 1 comes off and the rear door 1
is in a state where the door can be opened by rotating at the rotating shaft 5.
When the cargo platform 17 continues to rise, the rotating arm 2 becomes extremely easy to rotate upward around the slide shaft 6.Then, when the cargo 8 begins to descend and hits the rear door 1 and a force is applied to push it open, the rotating arm 2 slides. The shaft 6 rapidly slides from the front of the slide groove 10 toward the rear in the direction of the arrow 14,
Rotating arm 2 rotates upward as shown by arrow 15.
Therefore, the rear door 1 also rises. If the slide shaft 6 slides the entire length of the slide groove 10, the rear door 1
The opening of the rear door is maximized, and furthermore, if a large cargo mass hits the rear door 1, the rear door 1 rotates upward about the rotating shaft 5, so the opening area of the rear door becomes even larger, so even large cargo masses can be dumped without difficulty. I can do it. When the rotary arm 2 rotates upward, the support arm 3 rotates in the direction of the arrow 16 about the support shafts 4 and 7 to stand up, and the rotary arm 2
, and also prevents its lateral wobbling. In addition,
As shown in FIG. 2, when the support arm 3 of the first embodiment is replaced with a support plate 3', the support plate 3' is in contact with the side surface of the loading platform 17, so the rotating arm 2 and the rear door 1 are more stable. (to prevent lateral vibration) and perform upward and downward movements. Furthermore, since the triangular space 18 in the first embodiment formed by the rotating arm 2, the support arm 3, and the guide plate 11 is closed, there is no risk of dirt leaking from this space 18 or dirt entering this space 18. It is also possible to eliminate the jamming and prevent obstacles to the lifting or lowering of the rotary arm 2 due to sand and dirt.

Since the present invention has the above-described effects, when the cargo 8 descends to a state where upward rotation is easy due to the rise of the cargo platform 17 and touches the rear door 1, the slide shaft 6 rapidly moves into the slide groove. 10 slides downward in the direction of the arrow 14, the rotating arm 2 rotates upward as shown by the arrow 15, and the rear door 1 rises, and the drop port for the cargo 8 opens wide, causing the cargo 8 to collide with the upper edge of the rear door 1. There is no risk of damage to the rear door 1, and there is no need to remove the heavy rear door 1 just before the load is dumped to prevent damage, as is the case in the past, so work efficiency is improved. In addition, the dump truck is free from accidents such as the cargo getting caught on the rear door and the load being applied to the rear of the vehicle, which causes the dump truck to overturn. Therefore, dumping work can be carried out with peace of mind in any terrain.

Next, since the structure of the present invention is extremely simple, it is not only easy to install, but also inexpensive and reduces the economic burden.

Furthermore, this invention has many advantages, such as being able to stably support the rotating arm 2 and the rear door 1 by having the support arm 3, and also being able to prevent them from moving sideways.

[Brief explanation of drawings]

FIG. 1 is a partial side view of a dump truck equipped with a rear door opening/closing device of the present invention according to a first embodiment, and is an explanatory diagram showing a state in which the door is opened. FIG. 2 is a partial side view of the second embodiment. DESCRIPTION OF SYMBOLS 1... Rear door, 2... Rotating arm, 3... Support arm, 4... Support shaft, 7... Support shaft, 10...
...Slide groove, 11...Guidance plate.

Claims (1)

[Claims] 1. A guide plate 11 having a slide groove 10 is attached to the upper rear edge of the loading platform side plate 12, and the tip of the rotary arm 2, which has the rear door 1 rotatably pivoted to the rear end thereof, slides and rotates in the slide groove 10. One end of the support arm 3 is pivotally connected to the rear end of the guide plate 11 so that the support arm 3 can be raised and lowered.
A rear door opening/closing device for a dump truck loading platform, characterized in that the other end is pivotally connected to an intermediate portion of the rotary arm 2.