JP2022106571A - Spot-welding structure and manufacturing method therefor - Google Patents

Abstract

To provide a spot-welding structure that is able to reduce stress at a spot-welding point at an end of a reinforcement beam material without changing the arrangement of the reinforcement beam material while restricting an increase in manufacturing time and cost, and to provide a method for manufacturing the same.SOLUTION: A spot-welding structure 500 includes: a main plate 1; a reinforcement beam material 2 fixed to the main plate 1 by spot-welding and reinforcing bending rigidity of the main plate 1; and a reinforcement plate 4 arranged on the main plate 1 across a virtual straight line passing through two first spot-welding points at longitudinal end of the reinforcement beam material 2. The reinforcement plate 4 is fixed to the main plate 1 by spot-welding, and a plurality of second spot-welding points between the reinforcement plate 4 and main plate 1 are arranged across the virtual straight line.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a spot welded structure and a method for manufacturing the same.

Conventionally, in a spot welded structure for a railroad vehicle, a reinforcing beam material having a flange formed by bending a hat cross-sectional shape on a thin main plate is spot welded at a large number of welding points to reinforce the main plate. Since it is known that the stress at the spot weld point increases at the end of the reinforcing beam material, a structure for improving the deformation resistance and buckling strength of the main plate is adopted.

For example, in order to reduce the stress generated at the spot weld point at the end of the reinforcing beam material, the spot weld point is increased by expanding the spot welded flange portion or providing another flange portion at the end portion. ..

When the above construction is impossible, or in order to further reduce the stress, the method of fixing the main plate and the reinforcing beam material disclosed in Patent Document 1 with an adhesive layer may be used alone or in combination.

Further, Patent Document 2 discloses a spot welding method for preventing a decrease in rigidity at an end portion of a combination of a main plate and a reinforcing beam material. A reinforcing beam material whose reinforcing parts are laser-welded in advance is spot-welded to the main plate. Then, in order to increase the rigidity of the end portion, the reinforcing component and the main plate are spot welded.

Jikkai Sho 61-18771 Japanese Unexamined Patent Publication No. 2006-27366

When increasing the number of spot weld points, an additional area for spot welding must be secured on the main plate. Further, for this reason, there are problems such as wasteful material removal for the additional flange and addition of bending process in the production of the reinforcing beam material.

The method of Patent Document 1 does not require an additional area for spot welding, but has a problem that the number of steps of applying and curing the adhesive increases, and the manufacturing time and cost increase.

Further, in the method of Patent Document 2, since the reinforcing component is preliminarily integrated with the reinforcing beam material, the buckling strength of the main plate is improved, but the stress at the spot weld point at the end of the reinforcing beam material is increased. Does not reduce.

The present disclosure has been made in view of the above reasons, and the stress at the spot weld point at the end of the reinforcing beam material is stressed without changing the arrangement of the reinforcing beam material while suppressing an increase in manufacturing time and cost. It is an object of the present invention to provide a spot welded structure capable of reducing stress and a method for manufacturing the same.

In order to achieve the above object, the spot welded structure of the present disclosure is attached to the main plate, a reinforcing beam material which is fixed to the main plate by spot welding to reinforce the bending rigidity of the main plate, and a longitudinal end portion of the reinforcing beam material. It is provided with a reinforcing plate arranged on the main plate across a virtual straight line passing through two first spot welding points, and the reinforcing plate is fixed to the main plate by spot welding, and a plurality of the reinforcing plate and the main plate are fixed. The second spot weld point is arranged across the virtual straight line.

According to the present disclosure, the flexural rigidity of the combination of the main plate and the reinforcing plate is increased by the reinforcing plate fixed to the main plate by spot welding. As a result, when a load is applied to the main plate in the out-of-plane direction, the stress generated at the spot weld point with the reinforcing beam material due to the deflection of the main plate is reduced. Therefore, according to the present disclosure, a spot welded structure capable of reducing the stress at the spot weld point at the end of the reinforcing beam material without changing the arrangement of the reinforcing beam material while suppressing an increase in manufacturing time and cost. And its manufacturing method.

Perspective view showing the spot welded structure according to the first embodiment of the present disclosure. A side view for explaining the effect of the spot welded structure according to the first embodiment of the present disclosure. Top view showing the detailed arrangement of the spot welded structure according to Embodiment 1 of the present disclosure. In the spot welded structure according to the first embodiment of the present disclosure, the analysis result diagram showing (a) the thickness of the reinforcing plate and (b) the change in stress generated in the spot welded portion depending on the spot position. A plan view showing the arrangement of spot weld points of the reinforcing plate according to the second embodiment of the present disclosure. Perspective view showing a reinforcing plate used for the spot welded structure according to Embodiment 3 of the present disclosure. Perspective view showing another reinforcing plate shape used for the spot welded structure according to the third embodiment of the present disclosure. Perspective view showing the shape of the reinforcing plate used for the spot welded structure according to the fourth embodiment of the present disclosure. A perspective view showing a reinforcing plate used for the spot welded structure according to the fifth embodiment of the present disclosure. Top view showing the reinforcing plate used for the spot welded structure according to Embodiment 6 of this disclosure. A perspective view showing a spot welded structure according to a seventh embodiment of the present disclosure. A perspective view showing a reinforcing plate used for the spot welded structure according to the eighth embodiment of the present disclosure. A perspective view showing a spot welded structure according to a ninth embodiment of the present disclosure. Perspective view showing the spot welded structure according to the tenth embodiment of the present disclosure.

Hereinafter, specific embodiments of the spot welded structure according to the present disclosure will be described with reference to the accompanying drawings. In the following description, among the XYZ axes shown in the figure, the Y-axis direction is defined as the longitudinal direction of the reinforcing beam material and the reinforcing plate. The present disclosure is not limited by the following embodiments.

Embodiment 1.
FIG. 1 is a perspective view showing a spot welded structure 500 according to the first embodiment of the present disclosure. The spot welded structure 500 includes a main plate 1 and a reinforcing beam member 2 spot welded to the main plate 1.

The main plate 1 constitutes one wall surface of the structure. For example, the main plate 1 is a part of the housing. The main plate 1 is formed of a thin stainless steel plate. The outer circumference of the main plate 1 is fixed to another member (not shown) of the structure.

In order to reinforce the main plate 1 against a load in the out-of-plane direction, the reinforcing beam material 2 is fixed to the main plate 1 at a plurality of spot welding points 3. FIG. 1 illustrates only a part of the reinforcing beam member 2 including one end in the longitudinal direction. The reinforcing beam material 2 is formed of a thin plate of stainless steel. The reinforcing beam member 2 is bent in a hat shape in a cross section perpendicular to the longitudinal direction thereof. In other words, the reinforcing beam member 2 is a mounting portion formed in a flange shape along the main plate 1 from two edges of the U-shaped portion 2a having a U-shaped cross section and the U-shaped portion 2a, respectively. 2b and a mounting portion 2c are provided. A reinforcing plate 4 is fixed to the main plate 1 at a plurality of spot welding points 13 on the main plate 1 at the end position of the reinforcing beam member 2. The reinforcing plate 4 is not coupled to the reinforcing beam member 2.

Next, the arrangement of the spot welding points 13 and the reinforcing plate 4 will be described. The two spot weld points 13 sandwich the virtual straight lines AA passing through the two spot weld points 3 at the ends of the reinforcing beam material 2 in the drawing, and the distances from the virtual straight lines AA are S1 and S2. It is in the position of. In order to construct the spot welding point 13 at this position, the reinforcing plate 4 is arranged in a portion surrounded by the reinforcing beam material 2 and the main plate 1. At this time, the reinforcing plate 4 is spot-welded to the main plate 1 without protruding from the planar arrangement of the reinforcing beam member 2.

In the case of the prior art in which the reinforcing beam material 2 is provided with a flange different from the mounting portions 2b and 2c and additional spot welding is performed on the main plate 1, spot welding of the end portion of the reinforcing beam material 2 located on the virtual straight line of AA. Welding can only be done at a position about 20 to 30 mm away from point 3. This is because the current at the time of welding is diverted and normal spot welding cannot be performed. In the present embodiment, since the spot welding point 13 of the reinforcing plate 4 is fixed to the main plate 1 before the reinforcing beam material 2 is spot welded, the current diversion during welding does not occur.

When a load such as wind pressure, external pressure, or mechanical load acts on the main plate 1 reinforced by the reinforcing beam material 2 in the out-of-plane direction, the main plate 1 is bent. At this time, in the vicinity of the end portion of the reinforcing beam member 2, there is a region where the combined rigidity of the main plate 1 and the reinforcing beam member 2 is lost. Therefore, the curvature changes locally and the bending becomes large.

FIG. 2 is a side view of the bending deformation state of the combination of the main plate 1 and the reinforcing beam member 2. In the vicinity of the end portion of the reinforcing beam member 2, the curvature of the main plate 1 becomes large, so that an opening 52 is formed. At this time, it is known from stress analysis and the like that a large stress is generated at the spot welding point 3 at the end of the reinforcing beam member 2 as compared with the other spot welding points 3. Even if the pressure 51 is not large enough to break the plate material at the spot welding point 3 and its vicinity, if this repeatedly acts, fatigue cracks will occur at the spot welding point 3. The fatigue crack may gradually develop and penetrate the main plate 1 or the reinforcing beam member 2. In particular, since the spot weld point 3 has a structure in which the main plate 1 and the reinforcing beam member 2 are overlapped with each other, the mating surfaces act in the same manner as cracks and are prone to fatigue fracture. Therefore, it is important to suppress the opening amount of the opening 52 in order to correspond to the mode in which the crack opens with respect to the deflection of the main plate 1 in the out-of-plane direction.

The reinforcing plate 4 acts to suppress the opening amount of the opening 52. That is, the reinforcing plate 4 functions to relax the curvature of the main plate 1. For this purpose, it is necessary to arrange the reinforcing plate 4 at the above-mentioned position with respect to the spot welding point 3 at the end of the reinforcing beam member 2.

FIG. 3 is a plan view showing a more detailed arrangement of the spot welded structure 500 according to the first embodiment of the present disclosure. The width of the reinforcing plate 4 is W3, and the distance to the spot welding point 13 is defined as the spot positions S1 and S2 with reference to the end spot position 10 of the spot welding point 3 at the end of the reinforcing beam member 2.

4 (a) and 4 (b) show the stress generated in the spot welded portion due to the plate thickness T3 of the reinforcing plate 4 and the spot position S1 of the spot weld point 13 in the spot welded structure 500 according to the first embodiment of the present disclosure. It is an analysis result figure which showed the change of. In FIGS. 4A and 4B, S1 = S2 = 0.025m, respectively, and for other structural dimensions, the thickness T1 of the main plate 1 = 0.0015m and the thickness T2 of the reinforcing beam 2 = 0. The width W3 of the reinforcing plate 4 was set to .0015 m and 0.03 m. Further, the vertical axes of FIGS. 4 (a) and 4 (b) are represented as stress ratios, respectively. Since the spot welded portion can be regarded as a crack structure, it is considered appropriate to evaluate its fatigue strength by, for example, a fracture mechanics parameter using a stress intensity factor. However, here, the stress at the welding point is normalized by the result when the reinforcing plate 4 is not provided, from the point of being limited to a relative comparison. In the analysis, T3 = 0.0001 m when the reinforcing plate 4 was not provided.

FIG. 4A shows the influence of the plate thickness T3 of the reinforcing plate 4. The load caused the main plate 1 to be bent and twisted. As shown in FIG. 4A, since the stress is low when the thickness of the reinforcing plate 4 is T3 = 0.0015 to 0.03 m, the effect of the reinforcing plate 4 is clear even in the numerical experiment. When the width of the reinforcing plate 4 was W3 = 0.02 m at T3 = 0.0015 m, the stress was slightly higher than that at W3 = 0.03 m. From the result of FIG. 4A, if the reinforcing plate 4 becomes extremely thick, an adverse effect may occur, but when T3 = 0.0015 m, which is the same as the plate thickness T1 of the main plate 1, the effect of the reinforcing plate 4 is large. It turned out.

FIG. 4B is an analysis of the influence of the position S1 at the spot welding point 13. From the result of FIG. 4B, there is no effect when S1 is small, but the effect of the reinforcing plate 4 begins to appear at about 0.02 m, and the effect of the reinforcing plate 4 is stable within a range of about 0.025 m or more. It turned out.

Conventionally, when an out-of-plane load acts on the main plate 1 reinforced by spot welding, a structure for preventing fatigue damage at the spot welding point 3 at the end of the reinforcing beam member 2 has been adopted. For example, in order to reduce the stress generated in the portion, it is necessary to fix the main plate 1 and the reinforcing beam member 2 by adhesion or to provide a flange for increasing the number of spot points. On the other hand, in the present disclosure, the reinforcing plate 4 is fixed to the end of the reinforcing beam member 2 of the main plate 1 in advance by spot welding. In other words, a reinforcing plate 4 for increasing the bending rigidity of the main plate 1 is spot-welded to the main plate 1 at a position where the bending rigidity of the main plate 1 decreases. The reinforcing plate 4 is arranged so as to suppress bending of the main plate 1 in the vicinity of the spot welding point 3 located at the end of the reinforcing beam member 2. As a result, the combined rigidity of the main plate 1 and the reinforcing plate 4 suppresses the local increase in curvature of the main plate 1, and the amount of opening in the vicinity of the spot welding point where the stress increases is suppressed, thereby reducing the stress of the portion. It can be reduced. As a result, the conventional bonding or the additional flange can be eliminated. Further, by eliminating the bonding process, the manufacturing cost and the component cost can be reduced.

Embodiment 2.
FIG. 5 is a plan view showing the arrangement of spot weld points of the reinforcing plate 4 used in the spot weld structure 500 according to the second embodiment of the present disclosure. In FIG. 5, a plurality of spot welding points 13 for fixing the reinforcing plate 4 to the main plate 1 are constructed at three or more points and three or more rows in the longitudinal direction of the reinforcing beam material 2. In addition, in FIG. 5, a case where a plurality of spot welding points 13 are constructed in a row in the width direction of the reinforcing plate 4 corresponding to the direction of W3 in FIG. 3 is shown.

In the second embodiment, the flexural rigidity of the combination of the main plate 1 and the reinforcing plate 4 can be further increased by increasing the spot welding points 13 of the reinforcing plate 4 with the main plate 1. Therefore, the stress of the portion can be reduced by suppressing the opening amount in the vicinity of the spot welding point 3 at the end portion of the reinforcing beam member 2 which has a high stress. As a result, prior art bonding or additional flanges can be eliminated.

Embodiment 3.
FIG. 6 is a perspective view showing a reinforcing plate 4 used in the spot welded structure 500 according to the third embodiment of the present disclosure. The reinforcing plate 4 is not merely a flat plate shape, but includes a flat plate portion 80 and two ribs 81 erected from the edge portion in the width direction of the flat plate portion 80. The two ribs 81 are arranged in the longitudinal direction of the reinforcing plate 4. The rib 81 can be formed into the shape shown in FIG. 6 by bending in the process of manufacturing the reinforcing plate 4. Alternatively, as another method, a plate material manufactured as a separate part from the reinforcing plate 4 may be welded and fixed to the reinforcing plate 4 to form the rib 81.

FIG. 7 is a perspective view showing another reinforcing plate shape used for the spot welded structure 500 according to the third embodiment of the present disclosure. In addition to the flat plate portion 80 and the rib 81, the reinforcing plate 4 includes two flanges 82 bent from the tip end portion of the upright rib 81. The flange 82 is formed by further bending the tip of the rib 81. As a result, the cross-sectional shape of the reinforcing plate 4 is C-shaped in combination with the flat plate portion 80 and the rib 81. The flange 82 may be fixed to the rib 81 by welding as well as by bending.

In the third embodiment, the bending rigidity of the reinforcing plate 4 can be made higher than that of the flat plate shape of the first embodiment, and the bending rigidity of the combination of the main plate 1 and the reinforcing plate 4 can be further increased. As a result, the stress of the portion can be reduced by suppressing the amount of opening in the vicinity of the spot welding point 3 at the end portion of the reinforcing beam member 2 where the stress becomes high. Further, if the flange 82 is added, the bending rigidity of the reinforcing plate 4 can be further increased, and the above effect can be further enhanced.

Embodiment 4.
FIG. 8 is a perspective view showing the shape of the reinforcing plate 4 used in the spot welded structure 500 according to the fourth embodiment of the present disclosure. The reinforcing plate 4 is not merely a flat plate shape, but includes a flat plate portion 80 and two ribs 83 erected from the edge portion in the width direction of the flat plate portion 80. Each rib 83 includes two tapered portions 84 having a central portion in the longitudinal direction of the reinforcing plate 4 as an apex and being inclined toward the spot welding point 13.

In the fourth embodiment, the height of the rib 83 arranged on the side side of the reinforcing plate 4 decreases toward the spot welding point 13 of the reinforcing plate 4. Therefore, since the flexural rigidity of the reinforcing plate 4 is reduced at the spot welding point 13, the stress generated at the spot welding point 13 is reduced, so that fatigue damage is less likely to occur. Further, since the combined rigidity of the main plate 1 and the reinforcing plate 4 is increased, the opening amount in the vicinity of the spot welding point 3 at the end portion of the reinforcing beam member 2 can be suppressed, and the stress of the portion can be reduced.

Embodiment 5.
FIG. 9 is a perspective view showing a reinforcing plate 4 used in the spot welded structure 500 according to the fifth embodiment of the present disclosure. The reinforcing plate 4 is a laminated body of the laminated reinforcing plate 4a and the laminated reinforcing plate 4b. The main plate 1, the lap reinforcing plate 4a, and the lap reinforcing plate 4b are spot-welded on three sheets at the same time. Further, the laminated reinforcing plate 4a and the laminated reinforcing plate 4b may be spot-welded to the main plate 1 in which the laminated reinforcing plate 4b is fixed in advance by welding or adhesion.

In the fifth embodiment, the combined rigidity of the main plate 1 and the reinforcing plate 4 is increased by superimposing a plurality of the reinforcing plates 4. Further, by suppressing the amount of opening in the vicinity of the spot welding point at the end of the reinforcing beam material 2, the stress of the portion can be reduced.

Embodiment 6.
FIG. 10 is a plan view showing a reinforcing plate 4 used in the spot welded structure 500 according to the sixth embodiment of the present disclosure. The reinforcing plate 4 includes a mimi portion 85 extending outward in the width direction at a central portion in the longitudinal direction thereof. The Mimi portion 85 is formed so as to project from the reinforcing plate 4 so as to coincide with the inner surface of the reinforcing beam member 2 with respect to the fixed position on the main plate 1 of the reinforcing beam member 2. Along the longitudinal direction of the reinforcing plate 4, the Mimi portion 85 may be not only one location shown in the drawing but also two or more locations.

In the sixth embodiment, the combined rigidity with the main plate 1 is increased, and by suppressing the amount of opening in the vicinity of the spot welding point at the end of the reinforcing beam member 2, the stress of the portion can be reduced and the stress of the portion can be reduced. There is an effect that the positioning work of the reinforcing beam material 2 becomes easy.

Embodiment 7.
FIG. 11 is a perspective view showing the spot welded structure 500 according to the seventh embodiment of the present disclosure. In FIG. 11, a part of the U-shaped portion 2a at the end portion of the reinforcing beam member 2 is cut out to form the cutout portion 90. The notched portion is a portion of the U-shaped portion 2a parallel to the main plate 1. In addition, the U-shaped portion 2a erected from the mounting portion 2b and the mounting portion 2c remains. Round corners 91 are constructed at the two corners of the notch 90.

Further, the cutout portion 90 may further have a tapered cutout portion 92 shown by a broken line, which is a cutout of an upright portion of the U-shaped portion 2a of the reinforcing beam member 2.

In the seventh embodiment, the combined rigidity of the reinforcing plate 4 and the main plate 1 is increased, and the opening amount in the vicinity of the spot welding point at the end of the reinforcing beam member 2 is suppressed. As a result, in addition to being able to reduce the stress of the portion, the bending rigidity of the end portion of the reinforcing beam member 2 is reduced. As a result, the amount of opening in the vicinity of the spot welding point 3 at the end of the reinforcing beam material 2 is reduced. In addition, this makes it possible to reduce the stress of the portion.
Further, by constructing the tapered notch portion 92, the stress at the spot welding point 3 can be further reduced, and the fatigue strength can be improved.

Embodiment 8.
FIG. 12 is a perspective view showing a reinforcing plate 4 used in the spot welded structure 500 according to the eighth embodiment of the present disclosure. The reinforcing plate 4 includes a three-dimensional reinforcing plate 100 formed in a semicircular shape at the central portion in the width direction thereof. The three-dimensional reinforcing plate 100 extends in the longitudinal direction of the reinforcing plate 4.

In the eighth embodiment, since the bending rigidity of the reinforcing plate 4 is improved, the combined rigidity with the main plate 1 is improved as compared with the case of the simple flat plate-shaped reinforcing plate 4. As a result, by suppressing the amount of opening in the vicinity of the spot welding point at the end of the reinforcing beam material 2, the stress at the portion can be further reduced.

Embodiment 9.
FIG. 13 is a perspective view showing the spot welded structure 500 according to the ninth embodiment of the present disclosure. In FIG. 13, protrusions 2b1 and 2c1 extending in the longitudinal direction of the reinforcing beam 2 are formed on the mounting portions 2b and 2c, which are flanges at the ends of the reinforcing beam 2, respectively. Further, the protruding portions 2b1 and 2c1 may be formed by providing a notch at the end portion of the reinforcing beam member 2. The protrusions 2b1 and 2c1 are pressed against the main plate 1 by the pressing member 103. The pressing member 103 is provided with a step corresponding to the plate thickness of the mounting portions 2b and 2c so that the protruding portions 2b1 and 2c1 can be pressed against the main plate 1. Further, the above configuration including the pressing member 103 may be combined with the reinforcing plate 4.

In the ninth embodiment, when an out-of-plane load acts on the main plate 1, the amount of opening between the end portion of the reinforcing beam member 2 and the main plate 1 can be suppressed. Therefore, the stress at the spot welding point 3 at the end of the reinforcing beam member 2 can be reduced.

Embodiment 10.
FIG. 14 is a perspective view showing the spot welded structure 500 according to the tenth embodiment of the present disclosure. In FIG. 14, the reinforcing beam member 2 is the same as that of the first embodiment. Further, in the fourteenth embodiment, the pressing material 101 is provided. The pressing member 101 includes a reinforcing plate 101a corresponding to the reinforcing plate 4 of the above-described embodiment, and pressing plates 101b and 101c for pressing the mounting portions 2b and 2c at the ends of the reinforcing beam member 2.

The reinforcing plate 101a, the pressing plate 101b, and the pressing plate 101c are formed of one plate material. Therefore, the reinforcing plate 101a and the pressing plate 101b, and the reinforcing plate 101a and the pressing plate 101c are connected to each other. The reinforcing plate 101a is welded together with the main plate 1 at the spot welding point 13. The mounting portion 2c of the mounting portion 2b of the reinforcing beam member 2 is sandwiched between the main plate 1 and the pressing plate 101b and the pressing plate 101c without spot welding.

In the tenth embodiment, when the pressing member 101 creates an opening amount between the end portion of the reinforcing beam member 2 and the main plate 1, the opening amount can be suppressed. Therefore, the stress at the spot welding point 3 at the end of the reinforcing beam member 2 can be reduced. Further, the pressing member 101 extends slightly inward of the reinforcing beam member 2, and is spot-welded to the main plate 1 on the back side thereof. Therefore, similarly to the reinforcing plate 4, it is possible to suppress an increase in curvature caused in the main plate 1 due to the combined rigidity with the main plate 1. As a result, the stress at the spot welding point 3 can be reduced, and the same effect as that shown in the first embodiment can be obtained.

Embodiment 11.
In the structures shown in FIGS. 1 and 3, the spot welding points 13 have distances S1 and S2 in the longitudinal direction of the reinforcing beam material 2 with reference to the end spot position 10 of the spot welding point 3 at the end of the reinforcing beam material 2. It is in the position of. In the eleventh embodiment, the preferable values of S1 and S2 are set to 0.02 m to 0.04 m, respectively, based on the analysis result of FIG. 4 (b). 0.02m to 0.04m correspond to a relatively short distance within the range of S1 in which the stress ratio is reduced in FIG. 4B. Although S1 = S2 was set in the analysis, the values may be different from each other within the above range.

In the eleventh embodiment, the spot welding point 13 of the reinforcing plate 4 is located at the distances S1 and S2 with respect to the end spot position 10 of the reinforcing beam member 2, so that the end spot position 10 of the reinforcing beam member 2 is located. It is possible to suppress the amount of opening of the main plate 1 and the reinforcing beam member 2 in the out-of-plane direction in the vicinity of the spot welding point 3 at the position of. Therefore, the stress generated at the spot welding point 3 can be reduced, and the fatigue strength of that portion can be improved.

Embodiment 12.
In the twelfth embodiment, in the structures shown in FIGS. 1 and 3, the preferable plate thickness T3 of the reinforcing plate 4 is 0.001 m to 0.003 m. This is in consideration of the analysis result of FIG. 4A and the fact that the general plate thickness that can be spot welded is 0.006 to 0.003 m.

In the twelfth embodiment, by using the reinforcing plate 4 having the above-mentioned plate thickness T3, the stress generated at the spot welding point 3 at the end spot position 10 of the reinforcing beam member 2 due to the combined rigidity with the main plate 1 is generated. It will be reduced. Therefore, the stress generated at the spot welding point 3 can be reduced, and the fatigue strength of that portion can be improved.

Although the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the above-described embodiments and modifications, and various modifications and applications are possible.

In each embodiment, a reinforcing plate 4 is illustrated at one end of the reinforcing beam member 2. Not only this, the reinforcing plate 4 may be provided at the other end of the reinforcing beam member 2. Further, the structures of the respective embodiments may be combined at both ends of the reinforcing beam member 2.

In the tenth embodiment, the reinforcing plate 101a, the pressing plate 101b, and the pressing plate 101c of the pressing material 101 are formed from one plate. In addition to this, the reinforcing plate 4 of another embodiment may be provided, and the pressing material 101 may be composed of a combination of the pressing plate 101b and the pressing plate 101c.

In each embodiment, a typical example in which the reinforcing plate 4 is formed from a plate material is given. However, if the spot welding structure is possible and the combined rigidity with the main plate 1 can be increased, the reinforcing plate 4 having an arbitrary structure can be used.

In each embodiment, the virtual straight line connecting the two spot weld points 3 at the end of the reinforcing beam member 2 is orthogonal to the longitudinal direction of the reinforcing beam member 2. However, the virtual straight line does not necessarily have to be orthogonal to the longitudinal direction of the reinforcing beam member 2.

1 Main plate, 2 Reinforcing beam material, 2a U-shaped part, 2b Mounting part, 2c mounting part, 3 Spot welding point (first spot welding point), 4 Reinforcing plate, 4a Laminated reinforcing plate, 4b Laminated reinforcing plate, 10 End spot position, 13 spot weld point (second spot weld point), 2b1 protrusion, 2c1 protrusion, 51 pressure, 52 opening, 53 main plate fixing part, 80 flat plate part, 81 rib, 82 flange, 83 rib , 84 Tapered part, 85 Mimi part, 90 Notch part, 91 Round corner part, 92 Tapered notch part, 100 Three-dimensional reinforcing plate, 101 Pressing material, 101a Reinforcing plate, 101b Pressing plate, 101c Pressing plate, 103 Pressing material , 500 spot welded structure.

Claims (9)

Main board and
A reinforcing beam material that is fixed to the main plate by spot welding to reinforce the bending rigidity of the main plate, and
A reinforcing plate arranged on the main plate, straddling a virtual straight line passing through two first spot weld points at the longitudinal end of the reinforcing beam material, is provided.
The reinforcing plate is fixed to the main plate by spot welding.
A plurality of second spot weld points between the reinforcing plate and the main plate are arranged so as to straddle the virtual straight line.
Spot welded structure. The second spot welding points for fixing the reinforcing plate to the main plate are three or more points and a plurality of rows.
The spot welded structure according to claim 1. The reinforcing plate includes ribs that increase the bending rigidity of the reinforcing plate in the longitudinal direction of the reinforcing beam material.
The spot welded structure according to claim 1 or 2. The reinforcing plate is a laminated body in which two or more plates are stacked.
The spot welded structure according to any one of claims 1 to 3. The reinforcing beam material has a notch at the end.
The spot welded structure according to any one of claims 1 to 4. The reinforcing beam material includes a mounting portion provided with the first spot weld point.
The reinforcing plate includes a holding plate that presses the mounting portion against the main plate.
The spot welded structure according to any one of claims 1 to 5. The distance from the virtual straight line to the plurality of second spot weld points is 0.02 m to 0.04 m.
The spot welded structure according to any one of claims 1 to 6. The thickness of the reinforcing plate is 0.001 m to 0.003 m.
The spot welded structure according to any one of claims 1 to 7. A method for manufacturing a spot welded structure comprising a main plate and a reinforcing beam material that is fixed to the main plate by spot welding to reinforce the bending rigidity of the main plate.
The reinforcing plate is fixed to the main plate by spot welding across a virtual straight line passing through two first spot welding points at the longitudinal end of the reinforcing beam material.
A plurality of second spot weld points between the reinforcing plate and the main plate are arranged so as to straddle the virtual straight line.
A method for manufacturing a spot welded structure.

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