JPS5981237A - Swing door opening and closing apparatus for dump truck - Google Patents

Abstract

PURPOSE:To permit soil and sand to freely slide down, even if soil and sand are loaded onto a cargo deck over the height of a swing door, by installing, onto a dump truck, swing door opening and closing apparatus with which the swing door is opened widely and smoothly with a bracket arm by the pressure of soil and sand. CONSTITUTION:When a cargo deck 10 is tilted by a dump mechanism, lock for a swing door 20 is released, and the swing door 20 is opened rearward by receiving the pressure of soil and sand (a) which slide down. At the same time, a swing door arm 19 is turned upward, having a shaft 21 as fulcrum, and also the rotary wheel 23 of a supporting arm 22 turns and moves along and installation surface 26 for bracket and said supporting arm 22 pushes-up a pivotal contact part 21' upward, and a bracket arm 16 turns and moves upward, having a shaft 18 as fulcrum. That is, simultaneously with rearward opening of the swing door 20, also the pivotal contact part 21' of the swing door arm 19 is pushed-up automatically through the supporting arm 22, and therefore, the pressure received by the upper side part of the swing door 20 is reduced.

Description

[Detailed Description of the Invention] The present invention relates to a door opening/closing device for a dump truck, in which a dump mechanism tilts a cargo box to open the door and discharge materials such as earth, sand, gravel, etc. In conventional dump truck door opening/closing devices, the door can rotate backwards using the axis of the arm as a fulcrum. In this case, the upper side of the sliding door is subjected to heavy pressure due to the sliding earth and sand, making it difficult to rotate the sliding door around its axis. Therefore, it is often the case that dirt and the like fall over the fan door, completely burying the fan door and making it impossible to move the dump truck forward. There was also a danger that the center of gravity of the dump truck would shift to the rear when discharging earth and sand, causing the front wheels to lift up.

Furthermore, in the conventional fan door opening/closing device, the opening of the fan door is narrow, so if large rocks are mixed in with earth and sand, it is often impossible to remove them without removing the fan door, reducing work efficiency. In addition, if the opening of the fan door is narrow, it is impossible to unload the earth and sand into a narrow place, which requires a large storage area.

Therefore, conventional methods have been to raise the bracket or lengthen the fan door arm, but making the bracket higher increases the risk of being hit by power shovel packets while loading earth and sand. Furthermore, if the arm of the sliding door is made long, it is easy to break and the sliding door is difficult to operate smoothly when discharging the transported items.

Therefore, the present applicant devised a device to eliminate the above-mentioned drawbacks.
The invention was first filed as Utility Application No. 190128/1983), and the same invention produced excellent effects.

ing. However, when a particularly strong pressure is applied to the upper side of the fan door when discharging the transported object, the bracket arm connected between the bracket and the fan door 1 does not automatically lift up, and therefore the fan door does not open wide. Something happened.

This invention can be applied when a cargo box is loaded with earth, sand, gravel, etc. to a level exceeding the height of the sliding door, or when the cargo box is tilted sharply by a dumping mechanism, the pressure of the earth and sand will To provide a sliding door opening/closing device in which a door opens smoothly and widely together with a bracket arm, and earth and sand, etc., can freely slide down.

In addition, this invention makes it possible to carry out the work of transporting earth and sand efficiently and safely, and the structure of the opening/closing device is simple, simple, and strong, so that it will not be damaged. .

Next, an embodiment of the present invention will be explained in detail with reference to the drawings. Fig. 1 to Fig. 4 show one embodiment of the present invention, and
10 is a loading box of a dump truck 11; 12 is a bracket whose bottom portion is welded to the upper end of the wall on both sides of the 1° rear of the loading box;
The bearing part 13 and the pedestal part 14 are connected by a concave arc-shaped part 15. 16 is a bracket arm having an inverted U-shaped cross section and a back part 17, the front end of which is connected to the bearing part 14. Part 13
It is pivoted on a shaft 18, and its rear part rests on a pedestal part 14. Reference numeral 19 denotes a curved sliding door arm, the lower part of which is fixed to the upper side of the sliding door, the upper end of which is pivoted to the rear of the bracket arm 16 and the shaft 21, and the upper end of the sliding door arm 19. A support arm n configured on the lower side of the bracket arm 16 is provided in the section, and a rotary wheel movable along the concave arc portion 15 is provided with an axis at the tip of the support arm. The structure is such that the pivoting portion 21' of the shaft 21 can be lifted by movement of the shaft 21.

In the above example, the bearing part 13 and the pedestal part 14 are connected to the concave arc part 1.
5, but as shown in another embodiment shown in Figure 5, the pedestal part 14 and the concave arc-shaped part 15 may not be provided, in which case the lower part 5 on one side of the bearing part 13 is formed in an arc shape. (3) Will the rotating ring n follow the distortion of the bracket mounting surface? Easy to move. , Also, in the above example, the bracket arm 16 is formed into an inverted U-shape, and the inside! Although the support arm 7gρ is formed on the side 2, it does not necessarily have to be located inside the cerato arm, but can also be located on the lower side outside the racket arm. .

ζ According to this invention, when the cargo box 10 is tilted by the dump mechanism, the sliding door is unlocked, and the sliding door is opened so that the falling dirt a
When pressure is applied, the blade opens toward the rear. At the same time, the fan door arm 1.9 rotates upwards on the shaft 2X, and the support arm n also rotates along the concave arc portion 15 or the bracket mounting surface. Since the pivot portion 21' is pushed upward, the bracket arm 16 rotates upward using the shaft 18 as a support. ,
- 5.1 That is, in the device of this invention, when the fan door opens backward≦, at the same time, the support arm n automatically pushes up the pivoting part 21' of the fan fan arm, so that the side part of the fan gate ↓ The pressure received becomes weaker. Therefore, the height of the fan door (4
) Even when the cargo box is loaded with a large load, or when heavy pressure is applied to the door due to sudden tilting of the cargo box, the door can be opened smoothly and reliably together with the bracket arm 16, and at the same time, the ejection port can be opened as compared to the conventional system. Since it opens even wider, dirt, etc. can freely slide down from the wide-open outlet.

Also, according to this invention, there is no possibility that the dump truck would become stuck due to the sliding door being buried by falling earth and sand, or that the front wheels would be lifted up. Even if the object to be transported contains a fairly large rock b., it can fall freely without being caught by the sliding door, so that the object can be quickly discharged. Therefore, transportation work is safe and at the same time work efficiency can be improved.

...Furthermore, according to the present invention, transported materials such as earth and sand can be unloaded at a higher height than in Imaichi, so a narrow storage area can be used effectively. □ □・Furthermore, according to this invention, the structure of the opening/closing device is extremely simple and durable, and the fan door opens smoothly and reliably when discharging earth and sand, so that the bracket arm, fan door, etc. Damage to door arms, sliding doors, etc. can be prevented.

Note that the members of the swing door opening/closing device of the present invention can also be replaced with existing swing door opening/closing devices of dump trucks.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and Fig. 1 is a side view, Fig. 2 is a plan view, Fig. 3 is a cross-sectional view, Fig. 4 is a side view of the used state, and Fig. 5 is a side view. FIG. 3 shows a side view of an embodiment of the invention. 10...packing box, 12.fist/bracket, 1311
...Bearing part, 14.Fist/cradle part, 16..Bracket arm, 18..Shaft, 19.. Door arm.
Ka...Sakido, 21.Fist/axis, η...Support arm, Vessel...Rotating wheel, Sae...Axis.

Claims (1)

[Claims] A bracket is fixed to the upper end of both side walls at the rear of the dump truck, and the tip of the bracket arm is pivoted to the bracket, and the upper end of the sliding door arm whose lower part is fixed to the upper part of the side wall of the sliding door is fixed to the bracket. A swing door opening/closing device for a dump truck, comprising: a supporting arm extending below a bracket arm at the upper end thereof; and a rotary wheel provided at the distal end of the supporting arm.