JPS6325979B2 - - Google Patents

Description

[Detailed description of the invention] The present invention is provided at the rear opening of the loading platform, and depending on the type of cargo loaded on the loading platform, the sliding door can be selected to open downward or upward, allowing for versatile use. Regarding the rear sliding door of dump trucks, etc.

Generally, the rear sliding door of the loading platform of a dump truck, etc. has a pivoting part at the upper end, and when the loading platform is dumped, the rear sliding door opens around this pivoting part, so-called a downward swinging door. . When the downwardly-opening rear sliding door is used to unload a load by tilting the loading platform, the loaded object tends to get caught on the rear sliding door, which may cause problems in unloading. For this purpose, a method was adopted in which a pivot point was provided at a position one step higher than the height of the loading platform, and the rear sliding door was opened wide, but this had the disadvantage of having the pivot point protrude above the loading platform. Alternatively, there was a problem in which a large, lumpy load collided with the sliding door, causing damage. On the other hand, the top-opening door is pivoted to open upward by a rotation shaft provided on the floor of the loading platform, and when unloading the loaded item by tilting the loading platform, the loaded door Particularly, it is easy to discharge bulk loads, and there is little damage to the top-opening door and the loading platform. That is, although unloading using the upward swinging door can be carried out all at once in a short period of time, it is not possible to adjust the unloading amount of powdery loads such as gravel and discharge the load little by little.

In view of the above-mentioned points, the present invention eliminates the drawbacks of the prior art, allows for versatile use by selecting the unloading method depending on the type of loaded object, improves transportation efficiency, and prevents damage to the loading platform and sliding door. The purpose of the present invention is to provide a rear sliding door for a dump truck, etc., in which there is little noise.

According to the present invention, such a purpose is achieved by providing a platform which is rotatably provided by a lower rotating shaft provided at the lower part of the floor of the loading platform, and which opens the rear opening of the loading platform upwardly so as to allow the bulk load to be loaded. A top opening fan door for unloading,
One end contacts a fixed base fixed to the truck frame, and the other end is pivotally connected to a door operating arm provided on the top-opening door to close the rear opening with the top-opening door, thereby closing the rear opening on the loading platform. a link mechanism that separates from the fixed base and rotates the top-opening fan door upward until it reaches approximately the same plane as the floor surface to open the rear opening; and the top-opening fan door and the link. a link mechanism release means provided between the mechanisms and constantly releasing the closure of the rear opening by the top-opening fan door to make the rear opening a floor surface; By providing a downward-swinging door that is pivotally connected to an upper edge pivot portion provided on the upper edge and opens the rear opening downwardly by tilting the loading platform to unload the loaded powder and granular cargo. achieved.

Next, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention in a top-opening state, and FIG. 2 is an explanatory diagram of the operation in a tilted state of FIG. 1. 1 in Figures 1 and 2
is the loading platform of the dump truck, 2 is the main girder of loading platform 1, 3 is the upward-opening fan door, 4 is the fan door holder at the tip of the main girder 2, 5
is the fan door drive shaft. Further, the link mechanism 6 includes links 7 and 8, a sliding door operating arm 9, and a lever 10 that connects the link 8 and the sliding door operating arm 9. The link 8 is fixed to the swing door drive shaft 5, and the swing door operating arm 9 is fixed to the top-opening swing door 3. The top-opening fan door 3 is rotatably attached by a lower rotation shaft 12 provided at the lower part of the floor surface of the loading platform 1, and can open the rear opening 11 to open upward. The link 7 is fixed to the sliding door drive shaft 5 while maintaining a predetermined angle with the link 8, and a rotating roller 1 is attached to the tip of the link 7.
3 is pivoted. Note that the fixed base 14 is fixed to a subframe 15 of the truck frame, and is formed so as to be able to come into contact with the rotating roller 13 on its upper surface. Furthermore, the loading platform support shaft 16 pivotably supports the loading platform 1 in a tiltable manner. Furthermore, the upper pivot portion 17 is provided at the upper edge of the rear opening 11 of the loading platform 1, and a downward swing door 21 shown in FIGS. 3 and 4 is pivotally attached to this upper pivot portion 17. However, it is removed in FIGS. 1 and 2. Reference numeral 18 denotes a lever holding metal fitting for holding the lever 10, which is formed in an L-shape as shown in FIG. Reference numeral 19 denotes a bulk load loaded on this loading platform 1.

Next, the functions of the present invention will be explained using the above-described configuration. When the loading platform 1 is in a horizontal state as shown in FIG. Generates the driving force that rotates the This driving force causes the lever 10 to generate a rotational force in the direction of the arrow B, and the lower rotation shaft 12 to generate a rotational force in the direction of the arrow C. Therefore, the upwardly swinging door 3 holds the loading platform 1 in a closed state, as shown in FIG.

As shown in FIG.
The rotating roller 13 of the link 7 tends to move away from the upper surface of the fixed base 14. For this reason, the sliding door 3 rotates in the opening direction C ₁ about the lower rotation shaft 12 due to the weight of the bulk load 19 and the weight of the top-opening loading platform 3 . The lever 10 generates a rotational force in the direction of the arrow _B1 , and the sliding door drive shaft 5 generates a rotational force in the direction of the arrow _A1 . The rotating roller 13 opens the upwardly swinging fan door 3 while contacting the fixed base 14. As the tilting state of the loading platform 1 progresses,
The fan door 3 is opened wide, and when the fan door holder 4 and the back of the fan door 3 finally come into contact and the floor surface of the loading platform 1 and the surface of the fan door 3 reach almost the same plane, the link mechanism 6 starts operating. ends. Furthermore, if the loading platform 1 tilts,
The rotating roller 13 is completely separated from the fixed base 14,
This has nothing to do with the opening and closing of the top-swinging fan door 3. In this way, since the top-opening door 3 maintains substantially the same plane as the floor surface of the loading platform 1, the rear opening 11 is wide open, making it easy to discharge the bulk loaded material.

Next, the loading platform 1 returns to the horizontal state again with the loading platform support shaft 16 as the axis, and the rotating roller 13
When it starts to come into contact with the fixed base 14 again, the sliding door drive shaft 5 rotates in the direction of the arrow A. Due to this rotation, the lever 10 moves in the direction of the arrow B, and the lower rotation shaft 12
begins to rotate in the direction of arrow C. Furthermore, when the loading platform 1 returns to a completely horizontal state, the upward swing door 3 closes the rear opening 11 of the loading platform 1 and maintains this state.

The link mechanism 6 and the fixed base 14 are adjusted so that the top-swing door 3 opens and closes when the inclination angle of the loading platform 1 is about 10 degrees or less, and opens completely when it is about 10 degrees or more. .

Next, FIG. 3 is a schematic diagram of the structure with the downward swinging door shown in FIG. 1, and FIG. 4 is an explanatory diagram of the operation in the tilting state of FIG. 3. 1 in Figures 3 and 4.
Parts having the same functions as those in Figures and Figure 2 include:
The same reference numerals are given. The link mechanism release means, in this embodiment, the swing door open holding arm 20 is fixed to the top swing door 3 together with the swing door operating arm 9. As shown in Fig. 2, when the loading platform 1 is tilted,
After the top-opening fan door 3 rotates to be almost flush with the floor,
Remove the lever 10 of the link mechanism 6 from the sliding door operating arm 9. Next, as shown in FIG. 3, after the loading platform 1 is placed in a horizontal state, the lever 10 and the swing door open holding arm 20 are connected to ensure that the top swing door 3 is kept open at all times. At this time, the rotating roller 13 does not come into contact with the fixed base 14, and no driving force is generated in the sliding door drive shaft 5 in the direction of the arrow A as shown in FIG. In addition, this open top-swinging door 3 has a rear opening 1
1 floor surface is formed. The downward swinging door 21 is pivoted by an upper pivot portion 17 provided at the upper edge of the rear opening 11, and closes the rear opening 11. 23,
23A is a downward opening fan door 2 that closes the rear opening 11
This is a locking member provided to maintain the closed state of the device.

When tilting the loading platform 1, the locking members 23, 23A
The downward swinging fan door 21 whose locked state has been released is
Due to its own weight, it rotates about the upper pivot portion 17 to open downward. Due to this rotation, the powdery load loaded on the loading platform 1, such as gravel 22, is removed from the rear opening 1.
1, the cargo is discharged and unloaded without damaging the downward swing door 21.

After unloading, when the loading platform 1 is returned to the horizontal state, the top opening fan door 3 remains open, and the bottom opening fan door 21 closes to the upper pivot portion 17 due to its own weight.
, and closes the rear opening 11. Thereafter, the locking members 23 and 23A are operated to lock the downward swinging door 21 to the rear opening 11.

Next, FIG. 5 shows a schematic diagram of the bottom swinging door shown in FIG. 4 with a chain. In the figure, parts having the same functions as in FIG. 4 are given the same reference numerals. A chain 25 is provided between the downward swinging door 21 and the rear opening 11. By appropriately adjusting the length of this chain 25, the degree of opening of the downward swing door 21 is limited when the loading platform 1 is tilted. Therefore, the unloading speed of the loaded gravel 22, etc. is adjusted, and the gravel 22, etc. can be appropriately spread while moving the dump truck forward, without accumulating the gravel 22, etc. in one place behind the dump truck. After unloading, if the loading platform 1 is returned to the horizontal state, the chain 25 remains attached to the bottom opening fan door 21 and the rear opening 11, and the chain 25 remains attached to the bottom opening fan door 21.
1 closes the rear opening 11 again. Thereafter, the downwardly swinging fan door 21 is locked to the rear opening 11 by the locking members 23 and 23A.

Next, FIG. 7 shows a schematic configuration diagram of another embodiment of the present invention. When the downward swinging door 21 is opened downward, the upward swinging door 3 opens the rear opening 11 wide, so the fixed base 1 in FIGS. 3 and 4 is
4 is unnecessary. Therefore, in FIG. 7, the link mechanism release means, in this embodiment the fixture 26, includes an upper fixture 27, a lower fixture 28, a hinge 29 and a connecting fixture 30 provided on the upper and lower fixtures 27, 28. , 31. Lower fixture 28
is fixed to the subframe 15, and the upper fixture 27
is rotated rearward by a hinge 29. Due to this rotation, the rotating roller 13 of the link 7 does not come into contact with the upper fixture 27. That is, the link mechanism 6 maintains the top-opening fan door 3 in a wide open state, and when the loading platform 1 tilts, the link mechanism 6 locks the locking members 23 and 2.
Bottom opening fan door 21 released from locking state by 3A
is rotated to open downwards about the upper pivot portion 17 due to its own weight. By this rotation, the particulate load 22 is discharged rearward through the rear opening 11 and unloaded, similarly to FIG. 4.

After unloading, even if the loading platform 1 is returned to the horizontal state, the top swing door 3 remains open, and the bottom swing door 21 rotates about the upper pivot 17 due to its own weight. The rear opening 11 is closed, and the locking members 23 and 23A are operated to lock the downwardly swinging fan door 21 to the rear opening 11.

In addition, in order to give opening/closing operation to the top-opening fan door 3,
As shown in FIG. 8, it is only necessary that the loading platform 1 is tilted, the rotating roller 13 is sufficiently raised, and the hinge 29 is able to rotate the upper fixture 27 so as to place it on the upper surface of the lower fixture 28. At this time, the connecting fittings 30 and 31 are connected by the fixing pin 32. The link mechanism 6 is actuated by the connected fixture 26, and the top-opening fan door 3 can be opened and closed.

As described above, according to the present invention, the top-swinging door, the link mechanism that rotates the top-swinging door and opening the rear opening according to the tilting of the loading platform, and the top-swinging door and the link. a link mechanism release means provided between the mechanisms to unclose the rear opening and make the upward swinging door the floor surface of the rear opening; and a downward swinging door provided at the upper edge of the rear opening. By being equipped with this feature, the unloading method can be selected to open upward or downward depending on the type of cargo on the loading platform, reducing damage to the loading platform and sliding door, and allowing one dump truck to be used effectively. This improves transportation efficiency,
It has the advantage of being able to be used for so-called multiple purposes.

In addition, in the embodiment of the present invention, the sliding door opening holding arm 20 and the fixture 2 are used as the link mechanism release means.
However, the present invention is not limited to this, and it is also possible to provide means such as providing a fixing member movable forward or backward along the subframe.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure is an explanatory diagram of the operation in the tilting state of figure 1,
The figure is a schematic configuration diagram with a downward swinging door in figure 1, and figure 4.
The figure is an explanatory diagram of the operation in the tilting state of Figure 3, and Figure 5.
The figure shows a schematic diagram of the bottom-swinging door with a chain shown in Figure 4, Figure 6 shows a schematic diagram of the lever holding fitting, A is its front view, B is its side view, and Figure 7 is the invention of the present invention. A schematic configuration diagram of another embodiment, FIG.
FIG. 6 is an explanatory diagram of the operation in the tilted state shown in the figure. 1: Loading platform, 3: Top opening fan door, 6: Link mechanism,
11: Rear opening, 20: Sliding door open holding arm,
21: Bottom-opening fan door, 26: Fixture.

Claims (1)

[Claims] 1 In a dump truck or the like in which a loading platform 1 mounted on a truck frame is rotatably pivoted by a loading platform support shaft 16, the loading platform 1 is rotatably provided by a lower rotation shaft 12 provided at the lower part of the floor of the loading platform. A rear opening 11 of the loading platform is opened upward and a top-opening fan door 3 is used to unload the loaded bulk cargo, and one end is in contact with a fixed base 14 fixed to the truck frame and the other end is open upward. It is pivotally connected to a sliding door operating arm 9 provided on the sliding door, and closes the rear opening with the top opening sliding door, and when the loading platform is tilted, it is separated from the fixed base and the top opening sliding door is moved to the floor surface. A link mechanism 6 is provided between the link mechanism 6, which opens the rear opening by rotating upward until it reaches approximately the same plane as the rear opening, and the link mechanism 6, which is provided between the upward opening fan door and the link mechanism, and the link mechanism 6 is provided between the upward opening fan door and the link mechanism to constantly open the rear opening by the upper opening fan door. Link mechanism release means 20 for releasing the closure and making the floor surface of the rear opening part
and a powder or granule which is pivotally connected to an upper edge pivot portion provided at the upper edge of the rear opening and loaded with the rear opening opened downward by tilting of the loading platform. A rear swing door for a dump truck or the like, characterized by comprising a bottom swing door 21 for unloading a loaded object.