JP2018192501A - Closed section structure - Google Patents

Abstract

To suppress a support face for supporting an object from being deformed due to influence of welding distortion, in a closed section structure in which a fastening tool for welding and fixing the object on the support face of the closed section structure, by performing welding in a region outside a support face which does not gives influence of the welding distortion to the support face.SOLUTION: A closed section structure includes a fixing plate 20 fixed with a weld nut 30. The fixing plate 20 is weld to each of side wall surfaces 12 rising from both side end parts of a support face 11 in a state where a weld nut 30 is located on the support face 11.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a closed cross-section structure that supports an object using a surface that forms one side of a rectangular closed cross-section structure as a support surface.

  In the welding of a metal plate, welding distortion occurs in the welded portion, and the metal plate is deformed. An invention is known in which the influence of the weld distortion does not reach the periphery of the welded portion by causing the metal plate of the welded portion to protrude or be depressed in advance with respect to the welded strain of the welded portion (see Patent Document 1) ).

  11 and 12 show the invention of Patent Document 1. FIG. A convex portion B is formed on the metal plate A by embossing, and the welding member C is welded on the convex portion B. Although welding distortion occurs in the metal plate A by the weld bead D, the welding distortion is absorbed in the convex portion B, and the influence of the welding distortion on the entire metal plate A is suppressed.

JP-A-5-138391

  In the case of a closed cross-section structure that supports an object using one side forming one side of a rectangular closed cross-section structure as a support surface, a fastener for fastening the object may be welded to the support surface. At this time, if the area of the support surface is small, it is difficult to implement the invention of Patent Document 1. This is because it is not possible to ensure an area sufficient to form protrusions and depressions capable of absorbing welding strain on the support surface.

  An object of the present invention is to fix a fastener for fastening an object to a support surface of a closed cross-section structure by welding in a region outside the support surface that does not affect the weld distortion on the support surface. The object is to suppress the deformation of the support surface that supports the object due to the influence of welding distortion.

  1st invention is a closed cross-section structure provided with the fastener which supports an object by using one surface which comprises one side of a rectangular closed cross-section structure as a support surface, and fixes an object on the support surface. And the fixing plate which fixed the said fastener was provided, and this fixing plate is each welded to the side wall surface which stands | starts up from the both ends of the said support surface in the state which located the said fastener on the said support surface.

  In the first invention, the closed section of the closed section structure may be square. The welding to the side wall surface of the fixing plate may be performed along the end edge portion of the end portion extending from the fastener of the fixing plate to both sides, or may be performed along the both side portions of the end portion. The fastener may or may not protrude from the fixing plate to the object side. Moreover, a bolt, a nut, etc. can be used for a fastener.

  According to the first invention, the fixing plate is welded to the closed cross-section structure on the side wall surface different from the support surface. Therefore, the influence of welding distortion on the support surface can be suppressed. Moreover, a rising shape of the side wall surface is interposed between the support surface and the side wall surface. Therefore, even if the rising shape serves as a reinforcing structure of the support surface and welding distortion occurs on the side wall surface and deformation stress is generated, the influence of the deformation stress on the support surface can be suppressed.

  In a second aspect based on the first aspect, the fixing plate is welded to the side wall surface at an edge portion of an end portion of the fixing plate extending from the fastener to both sides.

  According to the second aspect of the invention, the deformation stress due to the welding strain is mainly generated in the direction along the edge of the end of the fixing plate on the side wall surface. On the other hand, the direction along the edge is reinforced by the rising shape of the side wall surface. Therefore, the influence of welding distortion on the support surface can be suppressed.

  According to a third aspect of the present invention, in the second aspect of the present invention, the weld bead accompanying the welding is formed at a central portion of the rising dimension of the side wall surface from the support surface.

  According to the third aspect of the invention, the deformation stress due to the welding distortion of the weld bead is generated so as to shrink in the direction along the edge at the central portion of the side wall surface in the rising direction. Therefore, although stress in the direction of bending the side wall surface is generated, no stress in the direction of bending the support surface is generated. Moreover, the stress in the direction of bending the side wall surfaces cancels each other between the side wall surfaces facing each other on both sides of the support surface, and does not deform the closed cross-section structure. Therefore, bending deformation of the support surface can be suppressed.

  4th invention is provided with the through-hole which penetrates the said fastener in the said support surface in any one of the said 1st-3rd invention.

  According to the fourth invention, at least a part of the fastener is stored in the closed cross section through the through hole. Therefore, the protrusion amount of the fastener from the fixing plate can be suppressed.

  According to a fifth invention, in the fourth invention, the fastener is a nut, and the nut is inserted into the through hole in a state where the fixing plate is positioned on the support surface.

  According to the fifth aspect of the invention, the nut that is the fastener is inserted into the through hole of the support surface. Therefore, the surface of the fixing plate that contacts the object can be a flat surface. In addition, since the fixing plate is welded to the side wall surface different from the support surface, it is possible to prevent the surface of the fixing plate contacting the object from being uneven due to the influence of welding. That is, the possibility of welding spatters adhering to the surface of the fixing plate that contacts the object is suppressed. Further, no weld bead is formed on the surface of the fixing plate that contacts the object.

  According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a rising dimension of the side wall surface from the support surface is smaller than a dimension between the side wall surfaces on both sides of the support surface.

  According to the sixth aspect of the invention, the rising dimension of the side wall surface from the support surface is made smaller than the dimension between the side wall surfaces on both sides of the support surface. That is, the closed cross-sectional structure is a rectangle. For this reason, the rigidity of the support surface against bending deformation of the side wall surface is enhanced. Therefore, it is possible to suppress the influence on the support surface due to the welding distortion generated on the side wall surface.

  According to a seventh invention, in any one of the first to sixth inventions, a plurality of combinations of the fixing plate and the fastener are provided on the support surface.

  When the support surface is deformed by welding distortion and a plurality of combinations of fixing plates and fasteners are provided on the support surface, the amount of deformation of the support surface increases as a whole. According to the seventh aspect, since the deformation of the support surface due to the welding strain is suppressed, when a plurality of combinations of the fixing plate and the fastener are provided on the support surface, the deformation suppression effect is further increased.

It is a top view which shows one Embodiment of this invention. It is a front view of the said embodiment. It is the III-III sectional view arrow of FIG. FIG. 4 is an enlarged view of a part IV in FIG. 3. It is a top view which shows the utilization example of the said embodiment. FIG. 6 is an enlarged view taken along the line VI-VI in FIG. 5. It is a front view corresponding to FIG. 2 which shows the modification of the said embodiment. It is a top view corresponding to FIG. 1 which shows the comparative example of this invention. It is a front view corresponding to FIG. 2 of the comparative example. FIG. 9 is a cross-sectional view taken along line XX in FIG. 8. It is a top view which shows the prior art example of this invention. FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. 11.

  1-3 show an embodiment of the present invention. This embodiment is a closed cross-section structure 10 to which a fixing plate 20 integrally provided with a weld nut 30 (corresponding to a fastener in the present invention) is fixed. As shown in FIG. 3, the closed cross-section structure 10 has a closed cross-section structure of a rectangle, and includes a support surface 11 that forms a long side of the rectangle and a side wall surface 12 that forms a short side of the rectangle. Therefore, in FIG. 3, the side wall surfaces 12 on both sides of the support surface 11 are formed in a shape that rises perpendicularly downward from the support surface 11. In addition, a through hole 13 for inserting the weld nut 30 is formed in the center portion of the support surface 11.

  The fixing plate 20 is formed so as to cover the support surface 11 and the side wall surface 12 of the closed cross-section structure 10. That is, the fixing plate 20 includes a support surface 21 corresponding to the support surface 11 of the closed cross-section structure 10 and a side wall surface 22 corresponding to the side wall surface 12 of the closed cross-section structure 10. A weld nut 30 is welded to the back surface of the closed cross-section structure 10 on the support surface 11 side at the center of the support surface 21 of the fixing plate 20. At the four corners of the weld nut 30, weld beads 50 are formed. A through hole 23 is formed in the support surface 21 of the fixing plate 20 corresponding to the screw hole 31 of the weld nut 30.

  The side wall surface 22 of the fixing plate 20 forms an end portion extending from the weld nut 30 on both sides, and the end edge portion 22a of this end portion is welded to the side wall surface 12 of the closed cross-section structure 10 by arc welding. Has been. Along with this welding, a weld bead 41 is formed on the end edge portion 22a. As shown in FIG. 4, the weld bead 41 is formed at the central portion (indicated by the alternate long and short dash line in FIG. 4) of the rectangular short side which is the rising dimension of the side wall surface 12 of the closed cross-section structure 10. For this reason, the side wall surface 22 of the fixing plate 20 is set to a dimension that is reserved by “L” with respect to the central portion. For example, L is about 1 mm. That is, the welding bead 41 is formed at the center of the rising dimension of the side wall surface 12 by reducing the size of the side wall surface 22 of the fixing plate 20.

  When the object is supported by the closed cross-section structure 10 configured in this way, an object (not shown) is placed on the support surface 21 of the fixing plate 20, and a bolt (not shown) is sandwiched between the objects. The object is fixed by screwing into the screw hole 31 of the weld nut 30. Since the weld nut 30 is welded to the back surface of the fixing plate 20, nothing protrudes from the support surface 21 of the fixing plate 20, and the support surface 21 can be widely used to fix the object.

  At this time, the weld bead 41 when the fixing plate 20 is welded to the closed cross-section structure 10 is on the side wall surface 12 of the closed cross-section structure 10 and not on the support surface 21 of the fixing plate 20. The support surface 21 is a flat surface and can stably support an object. Moreover, since welding for welding the fixing plate 20 to the closed cross-section structure 10 is performed on the side wall surface 12 of the closed cross-section structure 10, spatter during welding may adhere to the support surface 21. It can suppress and it can suppress that the surface of the support surface 21 becomes unevenness. Therefore, the object can be stably supported by the support surface 21.

  When welding is performed on the side wall surface 12 as described above, welding distortion occurs on the side wall surface 12. As a result, as shown by the arrows in FIG. 1, a deformation stress that shrinks the longitudinal direction acts on the side wall surface 12, and the side wall surface 12 is converted into a deformation stress that warps both ends in the longitudinal direction outward. . However, since the converted deformation stress works in the same manner on the side wall surfaces 12 on both sides, the deformation stresses cancel each other through the support surface 11 and the closed cross-section structure 10 is not deformed.

  Since the weld bead 41 is formed in the center of the rising dimension (dimension of the short side of the rectangle) of the side wall surface 12, the deformation stress acting in the left-right direction in FIG. Therefore, the closed cross-section structure 10 is not deformed in balance.

  As described above, the deformation stress generated in each part does not cause the closed cross-section structure 10 to be deformed because the respective stresses cancel each other out as a whole. However, if there is a positional deviation or a size imbalance of the weld bead 41, there may be a case where a deformation stress that deforms the closed cross-section structure 10 remains.

  According to the embodiment, the rising shape of the side wall surface 12 is interposed between the support surface 11 and the side wall surface 12. Therefore, even if the rising shape becomes the reinforcing structure of the support surface 11 and the deformation stress remains on the side wall surface 12, the influence of the deformation stress on the support surface can be suppressed.

  8 to 10 show a comparative example of the above embodiment. In this comparative example, the fixing plate 20 </ b> A is welded onto the support surface 11 of the closed cross-section structure 10. That is, both edge portions 20Aa of the fixing plate 20A are on the support surface 11, and arc welding is performed there. Therefore, the weld bead 43 is formed along both ends 20Aa. In addition, the structure other than this in a comparative example is the same as that of the said embodiment.

  According to the comparative example, welding distortion due to arc welding is generated on the support surface 11, and the deformation stress associated therewith is generated as shown by the arrows in FIG. As a result, the support surface 11 is curved by the deformation stress. According to the experimental results, the warpage amount of the support surface 11 of the comparative example was 0.5 mm / m. On the other hand, in the same experiment, the warpage amount of the support surface 11 of the embodiment was 0.05 mm / m. Therefore, in the embodiment, the deformation amount of the closed cross-section structure 10 can be reduced by 90% compared to the comparative example.

  5 and 6 show examples of utilization of the above embodiment. In this case, the closed cross-section structure 10 is formed in an elongated shape, and is configured such that the object 70 is supported across a pair of closed cross-section structures 10 arranged in parallel. Therefore, each of the four fixed plates 20 is welded to each closed cross-section structure 10 at an interval, and the support plate 60 is respectively bolted on the fixed plates 20 facing each other between the closed cross-section structures 10. (Not shown). The object 70 is supported across the pair of support plates 60.

  When a plurality of fixing plates 20 are welded to one closed cross-section structure 10 in this way, when the closed cross-section structure 10 of the comparative example is used, the closed cross-section structure 10 is deformed for each fixing plate 20A. When there are a plurality of fixing plates 20A, the deformation amount of the entire closed cross-section structure 10 becomes large. As a result, the object 70 may not be supported horizontally. On the other hand, when the closed cross-section structure 10 of the embodiment is used, the deformation of the closed cross-section structure 10 is suppressed, so that the object 70 can be supported while being kept horizontal. The closed cross-section structure 10 of the embodiment is useful when the object 70 must remain horizontal.

  As mentioned above, although specific embodiment was described, this invention is not limited to those external appearances and structures, A various change, addition, and deletion are possible in the range which does not change the summary of this invention. For example, in the said embodiment, although welding was performed along the edge part 22a of the edge part (side wall surface 22) of the adhering board 20, as shown in FIG. Welding may be performed along the side edge. In this case, a weld bead 42 is formed along the side edge. Since the weld beads 42 are dispersed in the vertical direction in FIG. 7 and are biased to the left side, a complicated welding distortion occurs on the side wall surface 12, and a deformation stress associated therewith is generated. However, even in this case, as in the case of the embodiment, since the rising shape of the side wall surface 12 is interposed between the support surface 11 and the side wall surface 12, the rising shape becomes a reinforcing structure of the support surface 11. Even if welding distortion occurs on the side wall surface 12 and deformation stress is generated, the influence of the deformation stress on the support surface 11 can be suppressed.

DESCRIPTION OF SYMBOLS 10 Closed cross-section structure 11 Support surface 12 Side wall surface 13 Through-hole 20 Fixing plate 21 Support surface 22 Side wall surface (end part)
22a edge 23 through hole 30 weld nut (fastener)
31 Screw hole 41, 42, 50 Weld bead 60 Support plate 70 Object

Claims (7)

A closed cross-section structure comprising a fastener that supports an object using a surface that forms one side of a rectangular closed cross-section structure as a support surface, and fixes the object on the support surface,
A fixing plate to which the fastener is fixed;
The fixing plate is a closed cross-section structure welded to each side wall surface rising from both end portions of the support surface in a state where the fastener is positioned on the support surface. In claim 1,
The closed cross-section structure in which the fixing plate is welded to the side wall surface at an edge portion of an end portion of the fixing plate that extends from the fastener to both sides. In claim 2,
The weld bead accompanying the welding is a closed cross-section structure formed at the center of the rising dimension of the side wall surface from the support surface. In any one of Claims 1-3,
A closed cross-sectional structure provided with a through hole through which the fastener is inserted in the support surface. In claim 4,
The fastener is a nut, and the nut is a closed cross-section structure inserted into the through hole in a state where the fixing plate is positioned on the support surface. In any one of Claims 1-5,
A closed cross-section structure in which a rising dimension of the side wall surface from the support surface is smaller than a dimension between the side wall surfaces on both sides of the support surface. In any one of Claims 1-6,
A closed cross-section structure in which a plurality of combinations of the fixing plate and the fastener are provided on the support surface.

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