JPH0155132B2 - - Google Patents

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 pivotally supported on a support frame at the rear of a loading platform, and is used to remove dirt, rotten materials, rock blocks, etc. This invention relates to a rear door opening/closing device for a dump truck that can transport cargo.

``Prior Art'' The rear door of a conventional dump truck is rotatably attached to the rear of a side plate, and is configured so that when dumping a cargo, the door lock is opened as the cargo platform rises, allowing the cargo to be dumped. However, if the cargo is rotten material or large chunks, the rear door is often damaged, and in such cases the rear door is removed from the loading platform to prevent damage. Also, when dumping sand or gravel, the load always gets caught in the rear door and cannot be completely unloaded, so the dump truck must be moved forward a short distance once or twice to lower the load. As described above, conventional dump trucks have had problems such as damage to the rear door and reduced efficiency when dumping cargo.

"Problems to be Solved by the Present Invention" In view of the problems of the prior art as described above, the present invention aims to solve the problems of the prior art as described above. While only the rear door can be opened and closed, if it is necessary to remove the rear door from the loading platform, such as when the cargo is a rock mass, the rear door, which is pivoted to the support frame, can be guided below the loading platform together with the support frame. Furthermore, it is possible to reliably prevent the rear door from rattling or opening while driving, thereby preventing damage to the rear door and improving the work efficiency of the cargo dump. To obtain a rear door opening/closing device for a dump truck which can prevent troubles caused by opening of the rear door during driving.

"Means for Solving the Problems" The rear door opening/closing device for a dump truck of the present invention includes a pair of support frames that are detachably attached to the loading platform of the dump truck, and a rear opening of the loading truck that is pivotally supported by these support frames. a rear door that covers the rear door; a door lock bar that is provided on the rear door and that fixes the rear door to the support frame so that the rear door does not open independently; It is characterized by comprising a support frame rotating shaft guided by a rear door storage guide provided.

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

Figure 1 shows the rear door 1 that covers the rear opening of the loading platform.
is attached to the support frames 2, 2 so that it can be rotated open and closed,
FIG. 3 is a perspective view showing a state in which the support frames 2, 2 are removably attached to the loading platform side plates 3, 3.

The support frames 2, 2 are made up of left and right support arms 4, 4, left and right vertical bars 5, 5, and a horizontal bar 6 which is integrally connected at the lower part of both vertical bars.
is formed in the shape of a right angle hook at the upper end of the vertical beam 5, so that it can be placed and attached to the side plates 3, 3 of the loading platform, respectively.

Reference numerals 7 and 7 denote frame support metal fittings, and these frame support metal fittings 7 and 7 are integrally formed on the outer walls of the tips of the left and right support arms 4 and 4, respectively, and the rear door 1 is attached to the support frames 2 and 2 as shown in the figure. It is removably attached to the loading platform side plates 3, 3 via frame support fittings and fixtures 8. Although bolts 8 are used in this embodiment to detachably attach the device, any technique may be used as long as it can be supported and attached to the side plate 3 of the loading platform.

The rear door 1 is mounted within left and right support frames 2, 2, and is pivoted to the support frames 2, 2 by rotating shafts 9, 9, respectively.

Numerals 10 and 10 are a plurality of door lock bars provided at appropriate locations on the rear door 1 to prevent the rear door 1 from opening alone when the dump truck is running. In other words, these door lock bars are attached to a latch 11 fixed to the outer wall of the rear door 1.
The rear door 1 and the left and right support frames 2, 2 are integrated by inserting the tip into a hole provided in each of the vertical bars 5, 5 of the support frames 2, 2. . 13 is the support frame rotation axis, and the vertical bar 5
It is integrally installed inward at the bottom of the
It is slidably fitted into the shaft guide groove 14 of the rear door storage guide 17 provided at the lower part of the platform bottom plate 12 shown in FIG.

Note that the support frame rotation shaft 13 may be a fixed shaft,
It may also be used as a rotating shaft. Further, as shown in FIG. 2B, a rear door storage guide 17 may be installed together with the rear door storage guide 17, which has a shaft guide groove 14 for the support frame rotating shaft 13 and a rear door receiver 15 formed in the outer lower part of the loading platform side plate 3. At this time, it is sufficient to make the support frame rotating shaft 13 longer by that amount.

Next, the rotation stopper 16 at the lower end of the support frames 2, 2 protrudes below the rear door storage guide as shown in FIG.
When the rotating upper part 16 is rotated approximately 90 degrees in the opening direction by the power of a hydraulic cylinder, which will be described later, the rotating upper part 16 comes into contact with the lower surface of the rear door storage guide 17 and stops.

Note that the support frame rotating shaft 13, the rotation stop portion 16, the rear door storage guide 17, and the shaft guide groove 14 are part of the rear door storage mechanism. Finally, FIG. 3 shows a mechanism for pulling the rear door 1 into the lower part of the cargo chassis 18 in the rear door storage mechanism.

That is, connecting arms 19 are provided at appropriate positions on the horizontal bars 6 of the support frames 2, 2, and a hydraulic cylinder 22 is attached to the lower part of the platform bottom plate 12, and its operating rod 21
and a connecting arm 19 are connected via a second connecting arm 20.

"Actions and Effects of the Present Invention" As is clear from the above explanation, the present invention has the following actions and effects.

(1) When traveling with earth, sand, rock blocks, etc. loaded on the platform, pass bolts 8 through the holes of the left and right frame support fittings 7 to secure the platform side plates 3, 3 and the left and right support frames 2, 2, respectively. At the same time, install the door lock bar 1.
0 and 10 to integrally fix or lock the rear door 1 to the left and right support frames 2, 2.

Therefore, even if the hydraulic cylinder fails while the dump truck is running, there is no risk that the rear door 1 will open independently, and therefore, the cargo will not spill onto the road.

(2) If there is a risk of damage to the rear door when dumping the cargo due to a rock mass, etc., remove the left and right fixings from the frame support brackets, and the support frame integrated with the rear door will remain fixed from the side plate of the cargo platform. is canceled.

When the loading platform is raised and the operating rod of the hydraulic cylinder is contracted, the rear door opens and rotates downward together with the left and right support frames about the support frame rotation axis. When the rear door rotates open,
Since the rotation stopper of the support frame of the rear door contacts the rear door storage guide, opening rotation of the rear door by approximately 90 degrees or more is prevented. When the support frame rotating shaft 13 moves forward within the shaft guide groove 14, the support frame 2 and the rear door 1 are simultaneously housed under the cargo platform chassis 18.

Therefore, it is not necessary to remove the rear door from the cargo platform as in the conventional case, and the rear door is not damaged.

(3) If the cargo is earth and sand and there is no risk of damaging the rear door during cargo dumping, it is sufficient to release only the lock without removing the bolts from the frame support fittings. In this case, when the cargo platform rises, the rear door opens naturally as the cargo slides, etc., since the rear door is pivotally supported within the left and right support frames.

Therefore, there is no need to remove bolts from the frame support fittings when dumping cargo, and therefore, the work efficiency is the same as that of a conventional general dump truck having only a rear door.

(4) In the case of the embodiment shown in FIG. 2B, the presence of the rear door receiver 15 of the rear door storage guide 17 allows the rear door to be stored in the lower part of the cargo chassis 18 more smoothly. In particular, when the rear door receiver 15 is provided with the trochanter 27, the storage can be carried out even more smoothly.

[Brief explanation of drawings]

1 to 4 are explanatory diagrams showing one embodiment of the present invention. Specifically, FIG. 1 is a partially perspective explanatory view of a loading platform showing a state in which the support frame, rear door, and rear door storage guide of the present invention are installed, and FIG. FIG. 2 is a perspective explanatory diagram showing a part of the device. Fig. 2B is a perspective explanatory view showing different examples of the rear door storage guide in the apparatus of the present invention, Fig. 3 is an explanatory view showing the rear door retracting mechanism provided at the bottom of the bottom plate of the cargo platform in the apparatus of the present invention, and Fig. 4 is an explanatory view of the rear door storage guide in the apparatus of the present invention. FIG. 6 is an explanatory diagram showing a state in which the rear door is operated and stored below the cargo platform chassis and a state in which the cargo is dumped. 1... Rear door, 2... Support frame, 3... Loading platform side plate, 7... Frame support fittings, 8... Fixtures, 10...
Lock rod, 21...operating rod, 22...hydraulic cylinder.

Claims (1)

[Claims] 1. A pair of support frames removably attached to the loading platform of a dump truck, a rear door that is pivotally supported by these support frames and covers the rear opening of the loading platform, and a mechanism installed on the rear door to prevent the rear door from opening independently. A rear door of a dump truck, comprising a door lock rod for fixing the rear door to the support frame, and a support frame rotation shaft that is integrally attached to the lower part of the support frame and guided by a rear door storage guide provided at the lower part of the cargo bed bottom plate. Switchgear.