JP2004284761A - Outer mast lower stay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer mast lower stay device for a high mast model having a lift as high as 5 m or more capable of precluding a crack in and breakage of an outer mast rail originating from a high stress in the welded end part of a lower stay in the revolving operation or running on a poorly conditioned road while it embraces long stretching object(s). <P>SOLUTION: The outer mast lower stay device is structured so that the lower stay 3 to be welded to each outer mast 1 of an industrial vehicle is furnished in its over-part with an extension part 31 in the shape of a concave arc of circle. A cylinder stay 2 or a second plate 5 is welded in such a way that the corners 11 of the outer mast 1 run off, and the welding part of the cylinder stay 2 with each outer mast 1 on the right and the left side is furnished with a third plate 6 for precluding a relative tumble of the cylinder stay and the outer mast. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an outer mastro astigmatic device for an industrial vehicle.
[0002]
[Prior art]
Conventionally, the outer mast astigmatic device has a plurality of plates welded to a lower portion of the outer mast. As shown in FIG. 4, a cylinder stay is mounted on a lower stud, and a general structure is formed by adding a first plate and integrating the same. Was.
[0003]
Patent Document 1 having another structure discloses a sheet metal configuration in which the mast inclination can be easily adjusted when the lower stay is welded to the outer mast.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H11-165998
Further, in the one shown in FIG. 5 or the one in Patent Document 2, the cylinder stay is separated from the outer mast by welding to reduce the influence of welding heat on the mast, reduce stress concentration, and improve the durability of the outer mast. Aiming for improvement.
[Patent Document 2]
Japanese Patent Publication No. 8-5628
[Problems to be solved by the invention]
However, in the above-mentioned conventional type, especially in a high-mast model with a height of 5 m or more, the stress at the weld toe portion between the outer mast rail and the lower stay is high during turning work or running on a rough road with a long load. The outer mast rail was sometimes cracked and damaged. Further, Patent Literature 1 is disadvantageous in that the distance between the mast and the mounting portion of the lower stay is reduced, and Patent Literature 2 does not mention the influence of welding heat of the lower stay on the mast or stress concentration. An object of the present invention is to solve such a problem.
[0007]
Means for Solving the Problems and Functions and Effects
The present invention has been made in view of the above-mentioned problems, and the invention according to claim 1 is characterized in that a concave arc-shaped extending portion is formed on an upper portion of an outer shape of a lower stay to be welded to an outer mast. Is an external astro-stay device.
[0008]
By adopting this configuration, the length of the weld line between the outer mast and the lower stay is extended, and the tensile load applied to the outer mast is transmitted in a dispersed manner by a cross-sectional change, thereby reducing the stress.
[0009]
The invention according to claim 2 is characterized in that the cylinder stay for the lift cylinder receiving stand is formed so as to wrap around the side surface of the outer mast, and a corner of the outer mast is released and welded. Device.
[0010]
This configuration is useful for improving the torsional rigidity against the swing of the outer mast and reducing the stress concentration at the corners, in addition to the function for the lift cylinder cradle.
[0011]
According to a third aspect of the present invention, the second plate for preventing the lower stay from falling down is formed so as to wrap around the side surface of the outer mast, and a corner of the outer mast is released and welded. Device.
[0012]
This configuration also contributes to the improvement of the torsional rigidity against the swing of the outer mast and the reduction of the stress concentration at the corners, as in the second aspect.
[0013]
According to a fourth aspect of the present invention, a third plate is provided at a welded portion between the cylinder stay and the outer mast on both the left and right sides to prevent the cylinder stay and the outer mast from falling relative to each other, and is positioned so as to avoid corners of the outer mast. The outer mast aster apparatus according to claim 1, wherein the outer mastro aster apparatus is welded.
[0014]
This configuration provides a rational arrangement of ribs corresponding to the roll of the outer mast, and helps to improve the stability performance of the mast.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of an outer mastroasting device according to the present invention, FIG. 2 is a top view thereof, and FIG. 3 is a rear view thereof.
[0016]
In FIG. 1, an outer mast 1 is a rail-shaped member formed in a U-shape, and a lower stay 3 is welded to a lower rear portion.
At the upper end of the lower stay 3, an extension of a concave arc 31 shape is formed in the outer shape toward the rear surface of the outer mast 1, and the cylinder stay 2 is placed on the lower stay 3, The concave arc-shaped extension portion 31 is attached so as to escape therefrom and to hold the outer sides of the left and right outer masts 1.
[0017]
Further, the first plate 4 is attached to support the left and right inner sides of the lower stay 3 and support the lower surface of the cylinder stay 2. A second plate 5 is further attached to the lower stay 3 so as to be one step lower than the cylinder stay 2 and connected to the outside of the outer mast 1.
[0018]
In addition to holding the outer mast 1 on the outside of the cylinder stay 2 and providing the second plate 5, the torsional rigidity against the sway of the outer mast is further improved for high-lift models, so that stable loading and unloading is achieved. Helps secure work.
[0019]
A third plate 6 forms a triangular rib straddling both sides of the attachment portion between the cylinder stay 2 and the outside of the outer mast 1, and this third plate 6 prevents the outer mast 1 from falling in the left and right side direction. It has the effect of reducing the roll by supporting it.
[0020]
The cylinder stay 2 and the second plate 5 wrapped around the outer mast 1 so as to be held by a gentle arc-shaped notch from the outer surface to the rear surface so as to prevent welding on the corner 11 of the outer mast 1. Is shaped to have a large, gentle arc-shaped notch avoiding the corners 11. This state is clear from the top view of FIG.
If there is no problem in strength or rigidity, the second plate may not be provided.
[0021]
In the case where the outer mast is a rail-shaped member formed by welding three thick plates in a U-shape, the outer mast 1 goes around the corner 11 forming the welding line of the outer mast 1 to form the cylinder stay 2 and the third mast. By attaching the two plates 5, the influence of the welding heat is reduced by avoiding the welding overlap at the corners, the stress concentration on the corners 11 of the outer mast 1 is reduced, the generation of cracks is prevented, and the durability is improved. Can be.
[0022]
Furthermore, by providing a concave arc-shaped extension at the upper part of the lower stay 3, the welding line between the outer mast 1 and the lower stay 3 is extended to disperse the stress in the base material, thereby reducing the average value of the stress. The stress can be greatly reduced by alleviating a sudden change in the cross-sectional area under load.
[0023]
In addition, since the cylinder stay or the second plate has a large, gentle arc-shaped notch to escape the corner of the outer mass, continuous welding of the lower stay and the mast becomes possible, and welding workability is improved.
Further, stress concentration on the cylinder stay and the second plate can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of an outer mastroasting device according to the present invention.
FIG. 2 is also a top view.
FIG. 3 is also a rear view.
FIG. 4 is a side view showing an example in which a lower stay is welded to a lower portion of a conventional outer mast. FIG. 5 is a side view showing another example of a conventional lower stay welding.
1 outer mast 11 corner 2 cylinder stay 3 lower stay 31 arc 5 second plate 6 third plate S fixed dimensions

Claims (4)

An outer mast aster stay device characterized in that a concave arc-shaped extension (31) is formed on the outer shape of a lower stay (3) to be welded to the outer mast (1). 2. An outer mast (1) according to claim 1, wherein the cylinder stay (2) for the lift cylinder cradle is shaped so as to go around the side surface of the outer mast (1), and the corner (11) of the outer mast (1) is released and welded. Mastro astey equipment. The second plate (5) for preventing falling of the lower stay (3) is formed so as to wrap around the side surface of the outer mast (1), and the corner (11) of the outer mast (1) is released and welded. 2. The outer mastroasting apparatus according to 1. A third plate (6) is provided at the weld between the cylinder stay (2) and the outer mast (1) on both the left and right sides to prevent the cylinder stay (2) and the outer mast (1) from falling down relative to each other. 2. The outer mast aster stay device according to claim 1, wherein the welding is performed by positioning and avoiding the corner (11) of (1).

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