JPS6044170B2 - lift arm plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a lift arm plate used in a tilting device for a loading platform installed in a dump truck or the like.

Conventionally, there are the following types of lift arm plates used in tilting devices for loading platforms installed in dump trucks and the like. In other words, thick plates are used, and predetermined parts are welded together to form a plate body with substantially triangular side surfaces, and a bearing boss is fixed to a predetermined part of the plate body, or a patent application filed by the present applicant. As disclosed in No. 54-12545, a pair of press-formed thin plates are welded together to form a three-dimensional structure, and bearings are attached to predetermined parts.In the case of the former, Since thick plates are used to provide strength, the weight cannot be avoided, and the production process is complicated because there are many welding points, and the plate has the disadvantage of being distorted by the welding heat.On the other hand, in the latter case This method requires a special press mold, and since it is manufactured by butting a pair of plate bodies, the plate bodies must have a fairly high bending accuracy.

The present invention solves the above-mentioned problems, and aims to provide a lift arm plate that is lightweight, has considerable strength, and can be manufactured through extremely simple steps.

Hereinafter, the configuration of the present invention will be explained based on the attached drawings showing one embodiment.
A tiltable cargo box pivoted to the subframe 3, the base of which is attached to the subframe 2
Hydraulic cylinder 04 is a lift arm having a substantially Ξ-angular shape, and each top of the lift arm is connected to the piston rod of hydraulic cylinder 3,
Pivots 6, 7, and 8 are attached to the packing box 1 and the tension rods 5. Reference numeral 9 denotes a pivot point between the other end of the tension rod 5 and the subframe 2.

Reference numeral 10 denotes a plate body, which has a long side 11 of a thin plate having a predetermined shape bent to have an L-shaped cross section, and a side 12 opposite to the long side bent to have an L-shaped cross section. , is formed in a substantially pentagonal shape. A plate material 13 is fixed to both sides 12 to form an L-shaped cross section. 14 is the two sides 12 and 1
A bearing boss portion A is formed by fitting the bearing 15 into the hole and fixing it together with the reinforcing member 16.

Further, the bearing boss portion B is constructed by fixing a bearing 18 sandwiched between a pair of plates 17, and the bearing boss portion C is also constructed from a pair of plates 19 and a bearing 20 in the same manner as described above.

Further, the bearing boss portions B and C are fixed to both ends of the plate body 10 with the bearing boss portion A as a reference.

The lift arm puto of the present invention constructed as described above has the following effects. In other words, by using a single thin plate material, the long side is bent into an L-shaped cross section by simple pressing, and the side opposite to the long side is bent into an L-shaped cross section to create a three-dimensional shape. Since the main body of the plate is formed by this structure, it is not only extremely easy to manufacture in terms of the manufacturing process, but it is also lightweight because thin plates are used as the constituent materials, and the predetermined three-dimensional structure is used. Despite its light weight, it has extremely high strength.

Further, since the plate main body is formed without requiring welding as described above, deformation due to internal distortion due to welding heat does not occur. Furthermore, the plate body can be formed by simple press machining, so that a special press mold is not required.

In addition, unlike the lift arm plate disclosed in the above-mentioned Japanese Patent Application No. 54-12545, a pair of press-molded plate bodies are butted and welded to form a three-dimensional structure, but it is made of a single thin plate. The plate body is made into a predetermined three-dimensional structure by simple press processing, and there is no need for butting, so high bending accuracy of the plate body is not required, and there is no problem with use even if the bending accuracy is low. do not have.

Next, the bearing boss part is attached to the plate body. After the bearing boss part A is fixed to the top of the plate body, a pair of plates 17 and 19 are fixed to both ends of the plate body with the boss part as a reference. All you have to do is position the configured bearing boss parts B and C, so even if bending errors or dimensional errors occur during the manufacture of the plate body, each bearing boss part A,
Considering the balance of the load applied to Bl and C, select the appropriate positions on both ends of the plate body so that the bearing boss is located in the best position so that the load is not unevenly distributed on a specific part of the lift arm plate. By fixing the plates 17 and 19 to the plate body, the bending errors and dimensional errors can be completely absorbed without any adverse effect on the lift arm plate.

Furthermore, in the conventional lift arm plate, which uses thick plates and is joined at predetermined points by welding to create a plate body with approximately triangular side surfaces, stress concentration occurs at the welded parts, but in the lift arm plate of the present invention, the plate body is press-finished. It is bent to form a three-dimensional structure, and there are few welded parts, so there are no stress concentration points, and it is safe even when used in a loading platform tilting device such as a dump truck without causing any damage during use. .

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a side view of a cargo box tilting device equipped with the lift arm plate of the present invention, and FIG.
37 is a longitudinal sectional view of FIG. 2, FIG. 4 is a front view of the lift arm plate, and FIG. 5 is a plan view of the same. 4... Lift arm, 10... Plate body, 11... Long side, 12, 12''...
Sides opposite the long side (two sides), A, B, C... Bearing boss part.

Claims (1)

[Claims] 1. In a substantially pentagonal lift arm plate main body having a long side bent into an L-shaped cross section, one side opposite to the long side bent into an L-shaped cross section, and a hole bored at the top, the above-mentioned A lift arm plate characterized in that a bearing boss part A is fixed to the hole, and bearing boss parts B and C are fixed to both ends of the long side.