JPS6138050B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a box lifting device comprising a fluid cylinder and a link mechanism.

[Conventional technology and its problems]

In conventional dump truck box lifting devices, as shown in Utility Model Publication No. 46-17602, the entire box lifting device was always disposed in front of the rear axle of the chassis. Therefore, it was not possible to mount the cargo box lifting device at a low position because the drive shaft, etc., which is located in front of the rear axle of the chassis, became an obstacle (there was a risk of interference with the drive shaft, etc.). Ta).

As a result, the height of the floor of the cargo box above the ground has increased, resulting in an increase in ground clearance when a dump truck or the like is loaded, resulting in poor running stability.

[Object of the present invention]

The present invention solves these conventional problems, and
The purpose of the present invention is to lower the floor surface of a cargo box by making it possible to mount a cargo box lifting device at a low position.

[Means for solving problems]

The box lifting device of the present invention has a triangular lift arm when viewed from the side, which has an inverted shape with its longest side facing upward, and whose frontmost apex is pivoted to the chassis side with a support shaft. , a rear end of a tension link is pivotally connected to the rearmost apex of the lift arm via a pivot shaft;
and a fluid cylinder is pivotally connected to the top of the remaining front-rear intermediate position of the lift arm, and further, the front end of the tension link and the front end of the fluid cylinder are pivotally connected to the cargo box side, and The shaft that pivotally connects the top of the lift arm and the fluid cylinder is disposed behind the rearmost axle of the chassis.

[Effect]

In front of the rearmost axle, there are many objects that may interfere with the vehicle, such as the drive shaft and differential case, but there are no such objects behind the wheel. Since the top of the lift arm is located at the intermediate position behind this, the cargo box lifting device can be mounted at a low position while avoiding interference with a part of the chassis side. It can be lowered.

〔Example〕

Hereinafter, the present invention will be explained based on the illustrated embodiment. Reference numeral 1 indicates a cargo box of a dump truck, 2 a chassis, which includes a rear part of a chassis frame 3, a drive shaft 4,
A differential case 5, a rear wheel 6, a leaf spring 7, etc. are illustrated, and a support shaft 8 is attached to the rear end of the chassis frame 3.
At the box 1, the cargo box 1 is pivoted so as to be able to tilt backwards as shown by the imaginary line, and the cargo box lifting device W performs the rearward tilting, and the loaded items in the cargo box 1 are discharged rearward.

Reference numeral 9 is a floor plate of the cargo box 1, 10 and 10 are a pair of main girders that are fixed to the back side of the floor plate 9 in parallel on the left and right sides, and 11 is a cross girder that bridges the main girders 10 and 10 on the left and right sides; The upper device W is mounted below the floor plate 9 in a storage manner. In addition, the lifting device W includes a pair of left and right chassis main girders 12, 12 and a pair of left and right main girders 10, 1.
Interposed between 0 and 0. 13 is the tree support and main girder 1
Receive 0,10. Furthermore, the illustrated example shows a case where subframes are omitted. Reference numeral 14 denotes a cross member bridging the left and right chassis main beams 12, 12, and the cross member 14 is disposed above or slightly in front of the rear wheel 6.

Thus, the box lifting device W has an inverted triangular shape when viewed from the side, with the frontmost apex A connected to the support shaft 1.
5, a lift arm 1 is pivotally connected to a cross member 14 and mounted in a state where it is tilted backward from the pivot support 15;
6, and the rear end of the lift arm 16 is pivotally connected to a pivot shaft 17 at the other top B of the lift arm 16, and the front end is pivotally connected to the crossbeam 11 of the cargo box 1 etc. by a support shaft 18 to receive tensile force. The middle part of the cylinder barrel 20 is pivotally connected to the tension link 19 and the remaining top C of the lift arm 16 by a shaft 21, and the tip of the piston rod 22 is pivotally connected to the crossbeam 11 of the cargo box 1 by a support shaft 23. The fluid cylinder 24 and the like are connected to each other. Moreover, the longest side of the lift arm 16 is an inverted triangular shape disposed above, and the tension link 1
The apex B, which is connected to the fluid cylinder 24, is arranged at the rearmost and uppermost position among the three vertices A, B, and C, while the apex C, which is connected to the fluid cylinder 24, is connected to the other two vertices A, B. This is the intermediate position between the front and back. Further, in the illustrated example, this apex C is located below the other two apexes A and B in the running state (solid line). Further, the support shaft 18 is disposed near the support shaft 23 and at a slightly lower position, and the tension link 19 and the center axis of the cylinder 24 intersect in an X shape when viewed from the side. Therefore, the thrust that pushes up the cargo box 1 becomes an upward vector along the straight line connecting the intersection point of the X-shape and the center point of the support shaft 15.

Thus, the shaft 21 that pivotally connects the top C of the lift arm 16 and the fluid cylinder 24 is located behind the rearmost wheel 25 of the chassis 2. More specifically, the shaft 21 is provided to project directly from the middle of the cylinder barrel 20 on the left and right, or (although detailed illustrations are omitted) is provided to project from an intermediate trunnion fixed to the cylinder barrel 20.
The rear end portion 26 protrudes sufficiently larger than the shaft 21 and the lift arm 16.

As is clear from the drawing, the cylinder 24
The shaft 21 of the rear wheel 6 is disposed behind the wheel 25 of the rear wheel 6, and the lifting device W is moved from the solid line to the virtual line in the figure.
Even if the rear end portion 26 of the cylinder barrel rises and swings as shown by arrow E, there is no interfering object on the side of the chassis 2, and the rear end portion 26 can be provided with a sufficiently large protrusion.

It should be noted that the present invention is not limited to the illustrated embodiment, and the design can of course be changed without changing the gist of the invention. Pivotally attached,
It is preferable that the piston rod 22 is pivotally connected to the top C of the lift arm 16, and the support shaft 18 and the support shaft 23 are not attached to the same crossbeam 11 but are attached to separate crossbeams, or via a bracket. One or both of them may be pivotally mounted on the back surface of the floor plate 9, and furthermore, the support shafts 18 and 23 may be arranged on the same axis or may be a single common shaft.

〔Effect of the invention〕

As described above, the present invention avoids the front of the last axle 25 where there is a risk of interference with the drive shaft 4, the chassis cross member, the differential case 5, etc.
A lift arm 16 is located behind the rearmost axle 25.
The configuration in which the shaft 21 is provided to pivotally connect the top portion C of the cylinder 24 to the cylinder 24 provides the following significant effects. The top C, which projects most downward among the links of the cargo box lifting device W, can be lowered to the maximum extent possible, and the space below the floor plate 9 of the cargo box 1 can be effectively utilized. Accordingly, the floor plate 9 of the cargo box 1 can be lowered, and the vehicle running stability can be improved. The center of gravity of the lifting device W itself is always at a low location not only when traveling but also when the cargo box is tilted (imaginary line), contributing to the stability of the vehicle. Serious vehicle accidents due to interference with the drive shaft 4 and the differential case 5 can be prevented.

[Brief explanation of the drawing]

The drawing is a side view showing an embodiment of the present invention. 2... Shaft, 15... Support shaft, 16... Lift arm, 17... Pivotal connection shaft, 19... Tension link, 2
1...Axle, 24...Fluid cylinder, 25...Last axle,
A, B, C...top.

Claims (1)

[Claims] 1. The lift arm 16, which has a triangular shape when viewed from the side, has an inverted shape with its longest side facing upward, and its frontmost apex A is pivotally connected to the chassis 2 side with a support shaft 15. The rear end of a tension link 19 is pivotally connected to the rearmost apex B of the lift arm 16 via a pivot shaft 17, and the remaining apex C of the lift arm 16 at an intermediate position between the front and back and the fluid cylinder 24 are pivoted by a shaft 21. and the shaft that pivotally connects the front end of the tension link 19 and the front end of the fluid cylinder 24 to the cargo box 1 side, and that pivotally connects the top C of the lift arm 16 and the fluid cylinder 24. 21 is arranged behind the rearmost axle 25 of the chassis 2.