JPS5912493B2 - Carton tilting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cargo box tilting device for tilting a cargo box mounted on a frame backward.

As the above-mentioned cargo box tilting device, for example, US Patent No. 3279
As described in the specification of No. 854, the front end of a lower rocking plate extending in the front-rear direction is rotatably supported on the frame, and on the other hand, the cargo lifter is mounted on the frame so as to be tiltable to the rear thereof, The rear end of the upper rocking plate extending in the front-rear direction is rotatably supported, and the rear end of the lower rocking plate and the front part of the upper rocking plate intersect with each other when viewed from the side of the frame. It is known that both ends of a telescoping cylinder and a fixed length link are pivotally connected to each other, and in this type, the lower swing plate is omitted and one end of the telescoping cylinder and fixed length link is directly pivotally connected to the frame. Compared to the connected structure, it has excellent advantages such as being able to shorten the maximum stroke of the telescoping cylinder, and significantly reducing the initial load of the telescoping cylinder when the cargo box is tilted, resulting in a smaller capacity. There is.

By the way, in the above conventional system, when the cargo box is laid down, the pivot support for the rear end of the upper swing plate of the cargo box is located at the rear side of the pivot support for the front end of the lower swing plate of the frame. , the pivot point for the upper rocking plate of the cargo box, that is, the point of application of the tilting moment applied to the cargo box by the cargo box tilting mechanism, is located relatively close to the cargo box tilting pivot, and the pivot point for the lower swing plate of the frame In other words, the connection points between the cargo box tilting mechanism and the frame tend to deviate relatively far from the cargo box tilting pivot, and as a result, the length of the arm of the above-mentioned tilting moment becomes relatively long, and the length of the arm of the telescopic cylinder increases. This is disadvantageous in terms of reducing the load, and the distance between the two shaft supports becomes relatively long when the cargo box is tilted, which is disadvantageous in shortening the maximum stroke of the telescopic cylinder.

In addition, in order to eliminate this disadvantage, if the upper and lower rocking plates are separated in the front-back direction and the front-back positional relationship of the two shaft supports is reversed, the telescopic cylinder and the Since the intersecting angle with the fixed length link becomes very small, the initial load on the telescopic cylinder increases when the cargo box is tilted, which is disadvantageous in reducing the capacity of the cylinder.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cargo box tilting device that eliminates all the disadvantages and inconveniences of the conventional devices and achieves a smaller capacity and a shorter stroke of a telescopic cylinder. , the rear end of a lower rocking plate extending in the front-rear direction is rotatably supported on the frame, and an upper rocking plate extending in the front-rear direction is attached to a cargo box mounted on the frame so as to be tiltable rearward. The front end of the plate is rotatably supported in front of the rear end shaft support of the lower rocking plate, and the frame is provided between the front part of the lower rocking plate and the rear part of the upper rocking plate. Both ends of the telescopic cylinder and the fixed length link, which intersect with each other when viewed from the side, are pivotally connected, and the frame is further provided with a stopper that restricts downward rotation of the lower rocking plate. .

Hereinafter, an embodiment in which the present invention is applied to a cargo box tilting device for a dump truck will be explained with reference to the drawings. In FIG. It is pivotably supported 3 so as to be tiltable.

A rear end of a triangular lower rocking plate 4 extending in the front-rear direction is rotatably supported on the frame 1, and a stopper 8 restricts the downward rotation of the lower rocking plate 4. is permanently installed.

On the other hand, at the bottom of the cargo box 2, the front end of a triangular upper rocking plate 9 extending in the front-rear direction is rotatably supported 10.
The front end shaft support 10 of the upper swing plate 9 is located in front of the rear end shaft support 5 of the lower swing plate 4 when the cargo box 2 is in an inverted state as shown in FIG.

Between the front part of the lower rocking plate 4 and the rear part of the upper rocking plate 9, both ends of a telescopic cylinder 14 and a fixed length link 13, which intersect with each other at an intersection 15 when viewed from the side of the frame 1, are provided. Pivotal connections 6, 11 near, 12 are provided.

When the telescopic cylinder 14 expands and contracts, a tensile force acts on the fixed length link 13 and the telescopic cylinder 1
A compressive force acts on 4, and a force pushing up the cargo box 2 acts on a straight line connecting the intersection 15 and the rotation axis 10.

1 as described above, when the telescopic cylinder 14 is extended in the state shown in FIG.
5 and the rotating shaft 10, the device receives a force and rotates upward around the tilting shaft 30.

During this time, as shown in FIG. 2, the lower swing plate 4 is not moving until the straight line connecting the intersection 15 and the front end shaft support 10 of the upper swing plate 9 reaches the rear end shaft support 5 of the lower swing plate 4. Stopper 8
Although it does not rotate at all while being supported by It begins to rotate upward around the pivot support 5.

In this state, the amount of extension of the telescoping cylinder 14 can be reduced by the amount corresponding to the amount of upward rotation of the lower rocking plate 4.

Each of the swing plates 4 and 9 firmly and reliably supports the link 13 and both ends of the telescopic cylinder 140, respectively.

When the telescopic cylinder 14 is contracted in the state shown in FIG.
While each of the swing plates 4 and 9 rotates around the two shaft supports 5 and 10, the cargo box 2 descends, and the lower swing plate 4 comes into contact with the stopper 8 as shown in FIG. Then, as shown in FIG. 1, the cargo box 2 returns to the horizontal position.

FIG. 4 shows the changes in the telescopic cylinder output with respect to the tilting angle of the cargo box 2, that is, the dumping angle, when measured by giving specific shapes and dimensions to each member of the configuration shown in FIG.
A graph is shown in which the load applied to the front end shaft support 10 is expressed as a multiple value.

From the graph of FIG. 4, it is possible to qualitatively grasp the tendency of change in the output of the telescopic cylinder with respect to the tilting angle of the cargo box according to the configuration of the present invention.

In FIG. 4, the distance between the front end shaft support 10 of the upper rocking plate 9 and the pivot joint 11 to the telescopic cylinder 14 is a
1 Fixed length link 13 between the pivot connection part 11 and the upper swing plate 9
When b is the distance between the pivot connection part 12 and the
The solid line shows the case where a:b=1.5=1, and the dotted line shows the case where a:b=
The case of 1:1 is shown, and the chain line shows the case of a:b=2:1.

As is clear from the trends of these curves, according to the present invention, the output of the telescopic cylinder with respect to changes in the tilting angle of the cargo box is greater than the trends of similar curves for any conventional cargo box tilting device. The degree of change in the multiple value with respect to the load is small.

In the conventional device, the multiplier value of the output of the telescopic cylinder to the load in the small dump angle range is much larger than the similar multiplier value in the present invention.

In particular, when a:b=1.5:1, the change in the multiple value of the output of the telescopic cylinder with respect to the load is smaller than in other cases.

From many measurement results, a: b=1.5: 1
It has been found that a ratio of 1 or a ratio close to this is suitable.

As described above, according to the present invention, the rear end of the lower rocking plate extending in the front-rear direction is rotatably supported on the frame, and on the other hand,
A front end of an upper rocking plate extending in the front-rear direction is rotatably supported in front of a rear end shaft support of the lower rocking plate on a cargo box mounted on the frame so as to be tiltable to the rear; Between the front part of the lower rocking plate and the rear part of the upper rocking plate, both ends of a telescoping cylinder and a fixed length link, which intersect with each other when viewed from the side of the frame, are pivotally connected, so that the frame As a result of vertically overlapping the rear end of the lower rocking plate that is pivotally supported and the front end of the upper rocking plate that is pivotally supported by the cargo box, the two rocking plates can be arranged relatively close to each other in the front-rear direction. With this close arrangement, it is possible to set the intersection angle between the telescopic cylinder and the fixed length link relatively large when the cargo box is in a prone state, thereby further reducing the initial load on the telescoping cylinder when the cargo box is tilted. Therefore, it becomes possible to employ a telescopic cylinder with a relatively small capacity, which contributes to making the device lighter and smaller and reducing costs.

Furthermore, when the cargo box is in the prone state, the pivot support for the front end of the upper rocking plate of the cargo box is located in front of the pivot support for the rear end of the lower swing plate of the frame, so the longitudinal positional relationship of these pivot supports is reversed. Compared to the conventional system, the pivot point for the upper rocking plate of the cargo box, that is, the point of application of the tilting moment applied to the cargo box by the cargo box tilting mechanism, is located relatively far from the cargo box tilting pivot, and the frame is The pivot point for the lower rocking plate, that is, the connection point between the cargo box tilting mechanism and the frame can be shifted to a position relatively close to the cargo box tilting pivot, and as a result, the arm length of the above-mentioned tilting moment is reduced. It is possible to ensure a relatively long stroke and reduce the load on the telescoping cylinder, and the distance between the two shaft supports at maximum tilting of the cargo box can be made relatively short, allowing the use of a telescoping cylinder with a shorter stroke. become.

Furthermore, since the frame is provided with a stopper that restricts the downward rotation of the lower rocking plate, even if the lower rocking plate tries to rotate downward due to the reaction force when the telescopic cylinder is extended, the lower rocking plate will not rotate downward. Rotation can be reliably prevented by the stopper, and therefore the output of the telescopic cylinder can be efficiently transmitted to the cargo box.

[Brief explanation of drawings]

FIG. 1 is a side view of a cargo box tilting device according to an embodiment of the present invention, FIG. 2 is a partial side view showing the operating state of the device in FIG. 1,
FIG. 3 is a partial side view showing still another operating state of the device shown in FIG. 1, and FIG. 4 is a graph showing the operating performance of the device shown in FIG. 1... Frame, 2... Packing box, 4...
...Lower rocking plate, 8...Stopper, 9...
... Upper rocking plate, 13 ... Fixed length link,
14...Telescopic cylinder.

Claims (1)

[Claims] 1. The rear end of a lower rocking plate extending in the front-rear direction is rotatably supported on a frame, and the rear end of a lower rocking plate extending in the front-back direction is rotatably supported on the frame, and the front and rear ends of the lower rocking plate are rotatably supported on the frame. The front end of the upper rocking plate extending in the direction is rotatably supported in front of the rear end shaft support of the lower rocking plate, and between the front part of the lower rocking plate and the rear part of the upper rocking plate. The two ends of a telescoping cylinder and a fixed length link that cross each other when viewed from the side of the frame are pivotally connected, and the frame further includes:
A cargo box tilting device comprising a stopper that restricts downward rotation of the lower swing plate. 2. In the cargo box tilting device according to claim 1, the distance between the pivot support of the upper rocking plate relative to the cargo box and the pivot connection portion relative to the telescoping cylinder is equal to the distance between the pivot connection portion and the telescopic cylinder. , a cargo box tilting device configured to be set to approximately 1.5 times the distance between the fixed length link and the pivot connecting portion of the upper swing plate.