JPH0720467Y2 - Structure of connection part of square tube - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to two rectangular tubes having a rectangular cross-sectional shape with a hollow inside and having a cut surface cut obliquely to the longitudinal direction. When the cut surfaces are butted against each other, the
The present invention relates to a joint structure of a rectangular pipe welded to have a V shape.

2. Description of the Related Art A joint structure of the above type used for a frame structure such as a large-sized bus or a house, a frame of a vehicle, or other various structures is well known.

FIG. 4 is a perspective view showing an example of a conventional coupling portion structure.
For example, two rectangular tubes 1 and 2 made of steel plate are both 5th
As shown in the figure, it has a rectangular cross section with a hollow inside. Each rectangular tube 1, 2 has a cutting surface 3, 4 cut obliquely with respect to its respective longitudinal direction, these cutting surfaces are butted against each other, this portion is shaded As shown, the entire circumference is welded and integrated. The integrated rectangular tubes 1 and 2 are connected to each other at an angle of approximately 90 °, and have a substantially L shape.

The structure 5 composed of the square tubes 1 and 2 fixed as described above receives various loads when it is actually used. Here, the base end portion 6 of the first rectangular tube 1 is fixedly supported, and the entire structure 5 is supported in a cantilever shape, and the tip end portion 7 thereof is provided.
Considering the case where the loads indicated by F1 and F2 are applied to, the joints between the square pipes 1 and 2 due to these loads F1 and F2, especially the inner corner part that is bent into an L shape (upper and lower A points in the figure And point B) or a stress is intensively generated in the vicinity thereof, and there is a possibility that the joint portion is broken depending on the magnitudes of the loads F1 and F2. The load F1 causes a bending moment in the structure 5, and the load F2 causes a torsion moment in the rectangular tube 1. Therefore, the former is referred to as a bending load and the latter is referred to as a torsion load.

As described above, in the joint structure shown in FIG. 4, a large stress may be generated in the joint, so that the cut surface portions 3 and 4 of the square tubes 1 and 2 are welded as shown in FIG. In addition, two reinforcing plates made of, for example, steel plates at the joint between the two and in the vicinity thereof.
A joint structure is also adopted in which 8 and 9 are applied and these are welded to the square tubes 1 and 2 as shown by the diagonal lines. However, even with this configuration, it is difficult to effectively reduce the stress generated in the joint portion due to the torsional load F2. Moreover, since the two reinforcing plates 8 and 9 are used, the total weight of the structure 5 is increased,
In addition, when these reinforcing plates 8 and 9 are attached, it is necessary to perform welding over the entire circumference thereof, which makes it unavoidable that the attachment work is troublesome and the cost increases.

Therefore, instead of adding the reinforcing plates 8 and 9, the plate thickness of the double-sided pipes 1 and 2 is increased, and the strength thereof is increased to improve
Although it may be possible to prevent the inner corner portion from breaking at the joint portion of 1 and 2, this would not only increase the cost of the structure 5 but also increase the weight thereof.

Purpose The present invention is based on the above-mentioned recognition, and an object of the present invention is to provide a joint structure of a rectangular tube which can effectively reduce the stress of the joint and has a simple structure. is there.

In order to achieve the above-mentioned object, the present invention is a joint structure of the type described at the beginning, in which a partition plate is sandwiched between the cut surfaces so that the hollow parts inside the both rectangular tubes are shielded from each other. It proposes a structure in which a plate and a double-sided square pipe are welded and integrated over the entire circumference of the partition plate.

Embodiment Hereinafter, an advantageous embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of a connecting portion structure according to the present invention.
A perspective view similar to the figure, and FIG. 2 is an exploded perspective view thereof. The difference from FIG. 4 is that the partition plate 10 is sandwiched between the cut surfaces 3 and 4 of the double-sided pipes 1 and 2, and the partition plate 10 and the double-sided pipes 1 and 2 are connected.
Is welded over the entire circumference (ABCD) of the partition plate 10 as shown by hatching in FIG. 1, and these are integrated. The inner hollow portions of the both rectangular tubes 1 and 2 are blocked from each other by a partition plate 10. Other configurations are the same as those in FIG. Therefore, the portions corresponding to FIG. 4 in FIGS. 1 and 2 are denoted by the same reference numerals as those in FIG. 4, and the duplicate description thereof will be omitted.

According to the configuration shown in FIG. 1 described above, when a bending load F1 or a torsion load F2 is applied to the tip end portion 7 of the structure 5, the connecting portions of the rectangular pipes 1 and 2, particularly, the corner portion inside the bent portion. (A
Point and point B) and the stress generated in the vicinity
It can be reduced significantly compared to the configuration shown in FIGS. This is because the force applied to the joint is
It is thought that this is because the stress can be prevented from being concentrated on the inner corner portions A and B by being dispersed over the entire area. In any case, it has been confirmed by many experiments that the stress can be reduced especially at the inner corners A and B.

Further, since only one partition plate 10 is added, the weight of the structure 5 does not increase unlike the conventional example shown in FIG. 6, and the welding length is longer than that in the case of FIG. It is short and easy to connect the re-cornered tubes 1 and 2.

Next, in order to clarify the effect of the present invention, Table 1 shows a comparative example with respect to the maximum stress generated by the loads F1 and F2 and the joint rigidity of the joint. This shows the result of analysis by the finite element method, and for each square tube 1 and 2,
As shown in FIG. 3 (a), when the length is L, the width is W, and the height is H, L = 400 mm and W = H = 50 mm. Case I in Table 1 shows the conventional example shown in FIG.
I and III are the conventional examples shown in FIG.
The thickness t of each is 1.6 mm and 0.3 mm, respectively. In case IV, as shown in FIG. 3 (b), the partition plate 10 (thickness t = 1.6 mm) is fixed by welding, and Case V is the result of the configuration according to the present invention shown in FIG. The thickness t of the partition plate 10 in the case V is also 1.6 mm. Also, in Table 1, bending load F
The maximum stress generation position caused by 1 and the torsional load F2 is the inner corners (points A and B) in cases I, IV, and V as described above, but the reinforcing plates 8 and 9 were used. Case i
In I and III, it is the reinforcing plate. % In parentheses
Is the% of each value when each value of Case I is 100%
Is shown. The weight in the table indicates the weight increased by the reinforcing plate or the partition plate.

As can be seen from the above table, in the structure according to the present invention, it is possible to reduce the maximum stress generated while minimizing the increase in weight thereof, and the joint rigidity may be inferior to Cases II and III, There is no difference in that great rigidity is obtained.
Therefore, by constructing a building or the like using such a structure, it is possible to reduce the total weight thereof, increase the rigidity thereof, and suppress the generation of vibration noise.

Effect According to the present invention, when a load is applied to the tip of the structure, the force applied to the joint portion of the double-sided rectangular pipe, particularly the inner corner portion of the bent portion, is efficiently dispersed over the entire partition plate. It is possible to prevent the stress from being concentrated on the inner corner portion. Therefore, it is possible to prevent the inner corner portion from breaking without increasing the plate thickness of the rectangular tube or welding the reinforcing plate to the joint portion of the both rectangular shapes, thereby increasing the weight and cost of the structure. Can be suppressed.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a coupling structure according to the present invention, FIG. 2 is an exploded perspective view thereof, and FIGS. 3 (a) and 3 (b) are perspective views for supplementary explanation of the contents of Table 1. FIG. 4 is a perspective view showing an example of a conventional joint structure, and FIG. 5 is a cross-sectional view of a rectangular pipe.
FIG. 6 is a perspective view showing another conventional example. 1,2… square tube, 3,4… cut surface 10… partition plate

Claims (1)

[Scope of utility model registration request] 1. Two rectangular pipes each having a hollow rectangular cross-section inside and having a cutting surface obliquely cut with respect to the longitudinal direction, the cutting surfaces are butted to each other. , Almost L
In a joint portion structure of square pipes welded to form a V-shape, a partition plate is sandwiched between the cut surfaces so that hollow portions inside the both square pipes are shielded from each other. A joint portion structure in which and are integrally welded over the entire circumference of the partition plate.