JPH0367733A - Rear door opening and closing device for damp truck - Google Patents

Abstract

PURPOSE:To obviate the driving sources such as hydraulic cylinders, etc., by opening a rear door by its own weight with rising of a pallet, and supporting the rear door through a turnbuckle and a bent link on a bracket metal so as to be automatically closed with lowering the pallet. CONSTITUTION:When a bracket metal 16 is engaged with a stopper-piece 17 and a pallet 1 of a damp truck is in a horizontal state or in a lowered state, the turning movement of the pallet is restricted through a bent link 5 or a roller 8. As a result, a rear door 4 is constantly supported through a turnbuckle 6 and the bent link 5 on the bracket metal 16 so as not to be opened. On the other hand, when the bracket metal 16 is kept away from the stopper-piece 17 before the pallet 1 is placed in a horizontal state, restriction of the free end part of the bent link 5 is released to allow the rear door 4 to be opened. When the pallet 1 is raised, the free end part of the bent link 5 separates from the bracket metal 16, and thereby the rear door 4 is freely opened to a specified position.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention relates to a rear door opening/closing device for a dump truck, and in particular has a rear door at the rear of a loading platform that opens and closes when the loading platform moves up and down. This invention relates to a rear door opening/closing device for a large dump truck capable of transporting cargo.

``Prior art'' Conventionally, one example of this type of implementation was
There is something disclosed in the publication.

The rear door opening/closing device for the dump truck has a rear door of the loading platform, a pair of protrusions each protruding downwardly and outwardly from the lower portions of both sides when the rear door is in the closed state, and a pair of protrusions that protrude downwardly and outwardly from the bottom of both sides when the rear door is in the closed state. a guide extending forward to guide the protrusion along the lower surface of the loading platform in accordance with the position of the protrusion; a stopper for the protrusion provided at the rear end of the guide; A driven arm that is displaced forward along the guide and extended from the rear door to a forward position below the protrusion in an open state in which the rear door is displaced along the guide, and the driven arm. It consists of a hydraulic cylinder for opening and closing the rear door, which is installed between the front end and the lower surface of the loading platform in front of it.

However, in this embodiment, the rear door is opened horizontally to the floor of the loading platform, and although it is said that the loading capacity can be increased, the opening and closing of the rear door is performed using hydraulic pressure installed below the loading platform. Since this is done by the driving force of a cylinder, the structure is complicated and expensive, and if the hydraulic cylinder breaks down, there are problems such as a major impact on the transportation work.

"Problems to be Solved by the Present Invention" In view of the shortcomings of the prior art, the present invention is capable of increasing the loading capacity and opening and closing of the rear door with a simple structure without using a hydraulic cylinder etc. In addition, there is almost no risk of failure, and if the rear door does not close tightly to the loading platform due to clogging with earth and sand, it can be easily fixed. The purpose of this invention is to obtain an inexpensive rear door opening/closing device for a dump truck that allows the design of the opening angle of the rear door to be freely changed.

"Means for Solving the Problem" The rear door opening/closing device for a dump truck of the present invention comprises a rear door whose lower end is pivoted to the loading platform so that it opens outward from the upper end under its own weight when the loading platform rises, and the rear door. a bending link, the lower end of which is connected and pivoted to one end via a turnbuckle, and which is pivoted to a horizontal shaft suspended below the loading platform;
supporting the free end of the bending link so that the rear door is always closed when the loading platform is horizontal or lowered, and
The present invention is characterized by comprising a receiving metal fitting pivotally attached to a frame below the loading platform, and a stopper piece provided on the frame for regulating rotation of the receiving metal fitting when the receiving metal fitting supports the bending link.

"Embodiments of the present invention" The present invention will be described in detail below with reference to embodiments shown in the drawings.

In FIGS. 1 to 5, reference numeral 1 indicates a loading platform of a large dump truck 2. In FIG. 3 is the truck or frame of a large dump truck. Reference numeral 4 denotes a rear door that covers the rear opening of the loading platform, and the lower end of the rear door 4 is pivotally supported on the loading platform 1 so that it opens outward from the upper end under its own weight when the loading platform rises in an inclined state. Reference numeral 5 denotes a bending link whose one end is connected and supported via the lower end of the rear door 4 and a turnbuckle 6, and which is pivoted to a horizontal shaft 7 appropriately suspended horizontally below the cargo platform 1. In this embodiment, the link 5 is located near the center and has a length of approximately 135 mm.
It is bent at the same time, and a roller 8 is rotatably provided at its free end. However, the turnbuckle 6 is
A pivot 10 having a long hole 9 projecting diagonally downward and outward at the lower end of the rear door 4 as shown in FIGS. 2 and 4.
A rear connecting male screw rod 12 connected to the rear via a pivot pin 11.
, a front connecting male screw rod 14 connected to the pivot end of the bending link 5 via a pivot pin 13, and a turnbuckle main body 15 connecting these front and rear connecting male screw rods 12,14.

Next, reference numeral 16 denotes a receiving metal fitting that supports the free end of the bending link 5 via a roller 8 so that the rear door 4 is always closed when the loading platform 1 is horizontal or lowered, as shown in FIG. The metal fittings 16 are appropriately pivoted to the frame 3 in the loading platform direction.

Reference numeral 17 denotes a stopper piece that restricts the rotation of the receiving metal fitting 16 when the bending link is supported, and this stopper piece 17 is provided to protrude from an appropriate location on the frame 3.

"Function" In the above configuration, first, when the receiving metal fitting 16 is located on the solid line and stopped by the stopper piece 11 as shown in FIG. 4, when the loading platform 1 of the dump truck 2 is horizontal, Alternatively, when the bending link 5 is lowered, its rotation is restricted via the rollers 8.

Therefore, the rear door 4 is always supported by the receiving metal fitting 16 via the turnbuckle 6 and the bending link 5, and therefore cannot be opened freely. In this case, when the rear door 4 is not completely closed, the turnbuckle body 15
can be rotated to adjust the degree of closure.

On the other hand, if you want to increase the loading capacity of the loading platform 1 depending on the load, remove the receiving bracket 16 from the stopper piece 17 and rotate it in the direction of the imaginary line shown in FIG. 4 before the loading platform 1 becomes horizontal. When the cargo platform is lowered, the restriction on the free end of the curved link 5 is released, so that the rear door 4 opens to a horizontal position as shown by the imaginary line.

Next, when the loading platform rises, that is, when the loading platform changes from the horizontal state shown in FIG. 4 to the inclined state shown in FIG. 1
6, the restriction on the rear door 4 is released, and the rear door 4 opens to a desired position due to its own weight.

When the loading platform 1 is lowered, the roller 8 of the bending link 5 comes into contact with the receiving metal fitting 16, and the bending link 5 rotates counterclockwise around the horizontal axis 7 (with reference to FIG. 4). As a result, the rear door 4 is pushed by the turnbuckle 6 and closed.

"Effects of the Present Invention" As is clear from the above description, the present invention has the following effects.

(1) The rear door opens under its own weight as the loading platform rises, and
When the loading platform is lowered, it is supported by the receiving metal fitting via the turnbuckle and the bending link, so that the bending link rotates and automatically closes. Therefore, there is no need to use a hydraulic ring or the like as in the conventional case. Therefore, the structure is simple and can be manufactured at low cost.

(2) When it is desired to increase the cargo capacity U of the cargo platform, the rear door can be opened horizontally by simply rotating the receiving metal fitting in one direction and releasing the restriction on the bending link.

(3) A turnbuckle is installed between the rear door and the bending link, so if, for example, the rear door does not close properly on the loading platform due to blockage such as dirt, the degree of closing can be corrected by adjusting the turn pack. can do.

(4) In addition, by changing the extension angle of the pivot part 10 formed protrudingly at the lower end of the rear door, or by changing the size of the pivot pin 11 guide elongated hole 9 formed on the pivot part, etc. The design of the opening angle of 4 can be changed freely.

[Brief explanation of drawings]

1 to 5 are schematic explanatory diagrams showing one embodiment of the present invention. Incidentally, FIG. 1 is an explanatory diagram showing an example of the usage state of the present invention. 1... Loading platform, 3... Frame, 4...
・Rear door, 5...Bending link, 6...Turnbuckle, 7...Horizontal shaft, 10...Pivotal part,
16...Bracket fitting, 17...Stopper piece.

Claims (1)

[Claims] 1) A rear door whose lower end is pivoted to the loading platform so that it opens outward from the upper end under its own weight when the loading platform rises, and one end of which is connected and pivoted to the lower end of the rear door via a turnbuckle, and , a bending link pivotally connected to a horizontal shaft horizontally suspended below the loading platform, and supporting the free end of the bending link so that the rear door is always closed when the loading platform is horizontal or lowered, and This rear door opening/closing device for a dump truck consists of a receiving metal fitting pivotally attached to a frame below the loading platform, and a stopper piece provided on the frame for regulating the rotation of the receiving metal fitting when the receiving metal fitting supports the bending link.