JP2017200707A - Metallic box body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic box body which has high reliability to airtightness, and has good productivity, and a method of manufacturing that.SOLUTION: In a metallic box body 2, a bottom portion 10, and side wall portions 11 and 212 raised from an outer peripheral edge of the bottom portion 10 are formed from one metallic plate. The bottom portion 10 has a square shape, and the side wall portions 11 and 212 are welded on two side wall welding portions 212c having linear shapes in parallel with a raising direction, to form a square cylindrical shape having four side surfaces. The two side wall welding portions 212c are provided on either one side surface of the side wall portions 212, and are positioned at inner positions than both sides on the side surface.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a metal box that can accommodate various articles.

  Conventionally, a box formed by drawing a metal plate with a press machine is widely used as a metal box that can accommodate various articles. However, it is sometimes difficult to perform so-called deep drawing with high accuracy using a metal material having generally low ductility such as stainless steel or titanium. Therefore, Patent Document 1 discloses a box formed by bending a metal plate to form a U-shaped member and a L-shaped member, respectively, and then welding them. In this configuration, since drawing is not required, variations in wall thickness can be suppressed. However, in this case, both the long side portion and the short side portion of the box must be welded, and the weld length becomes relatively long. Therefore, in order to ensure high airtightness in this box, high reliability is required for the welded portion. Thereby, when manufacturing the box body by which high airtightness is requested | required, the one where welding length is short becomes easy.

  On the other hand, Patent Document 2 includes a single metal flat plate, a rectangular bottom portion, a pair of rectangular long wall portions erected on each long side portion of the bottom portion, and each short side portion of the bottom portion. A rectangular casing (box body) having a pair of rectangular short wall portions erected on each other is disclosed. In this configuration, the pair of long wall portions are formed by being bent from the long side of the bottom portion, and the pair of short wall portions are bent from both sides of the pair of long wall portions and welded to each other, and are also welded to the bottom portion. ing. According to this structure, since a long wall part is formed by bending, welding length can be shortened. Therefore, it becomes easy to secure high airtightness in the box, and high reliability is easily obtained. Moreover, since welding length is short, welding work can be reduced and the productivity of the box is increased.

JP 2002-198011 A JP 2013-8665 A

  However, in the configuration of Patent Document 2, since the bottom portion and the short wall portion are joined by welding at a corner joint, in order to ensure high reliability of the airtightness of the box body, High welding accuracy is required. In such a configuration, in order to obtain high welding accuracy, it is conceivable to increase the thickness of the metal plate (blank), which is a material for forming the box, but such as an increase in the weight of the box and an increase in manufacturing costs. Disadvantages arise. Moreover, in order to obtain high welding accuracy, it is conceivable to improve the welding position accuracy and the shape accuracy of the welded portion, and to sufficiently reduce the welding speed. However, these cause a reduction in productivity. Therefore, there has been room for further improvement in manufacturing a metal box body that can achieve high productivity while ensuring high reliability in terms of airtightness.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a metal box body having high airtightness reliability and excellent productivity, and a method for manufacturing the same.

One aspect of the present invention is a metal box formed by forming a bottom portion and a side wall portion erected from the outer peripheral edge of the bottom portion from a single metal plate,
The boundary part between the bottom part and the side wall part consists of a bending boundary part formed by bending both, and a welding boundary part formed by welding both.
At least a part of the weld boundary portion is provided with a superposition portion in which at least one of the bottom portion and the side wall portion is deformed to align both end portions and overlap each other in a planar shape. The edge joint welded part formed by welding the above-mentioned end part of the part is formed,
The bottom has a long rectangular shape having two short sides facing each other and two long sides facing each other,
The bending boundary part is formed on each of the two long sides,
The weld boundary includes the two short sides and corners of the bottom from both ends of the two short sides when viewed from the direction perpendicular to the bottom, and extends in parallel to the bending boundary and is bent. The metal box is characterized by being formed over a portion connected to the boundary portion.

Another aspect of the present invention is a method for manufacturing a metal box having a bottom portion and a side wall portion erected from the outer peripheral edge of the bottom portion,
A development body forming step of forming the development body of the metal box from a single metal plate,
Forming a superposition part by deforming at least one of the bottom part or the side wall part so that a superposition part can be formed by aligning the end part of the bottom part and the end part of the side wall part and superimposing both in a planar shape. A preparatory process for forming a polymerization part,
Bending the unfolded body to form a folded boundary portion at the boundary portion between the bottom portion and the side wall portion and to form the overlapping portion;
Welding the side walls and welding the end of the overlapped portion to form a welded joint at the boundary between the bottom and the side wall to form a weld boundary;
Including
The bottom has a long rectangular shape having two short sides facing each other and two long sides facing each other,
In the bending step, the bending boundary is formed on each of the two long sides,
In the welding process, the welding boundary portion includes the two short sides and the corners of the bottom portion from both ends of the two short sides when viewed from the direction perpendicular to the bottom portion, and parallel to the bending boundary portion. The method of manufacturing a metal box body is characterized in that the metal box body is formed over a portion extending and connected to the bent boundary portion.

  In the metal box, the boundary portion between the bottom portion and the side wall portion erected from the outer peripheral edge is composed of a bending boundary portion and a welding boundary portion. And the welding boundary part is provided with a superposition part formed by aligning both ends by deforming at least one of the bottom part and the side wall part and superimposing both in a planar shape, and the end part in the superposition part is provided. By welding, a lip joint weld is formed. “Helicopter joint welding” may also be referred to as “pain welding”.

  Since the shape of the weld joint at the weld boundary of the boundary between the bottom and side walls is an edge joint, the metal box is welded compared to welding with a square joint, butt joint or lap joint. Quality can be increased, and as a result, high reliability can be obtained with respect to airtightness, and productivity can be improved by improving yield. In addition, since the shape of the weld joint at the weld boundary is an edge joint, the weld strength at the weld boundary can be improved as compared with the case where other welding methods are employed. Therefore, since it is not necessary to use a thick metal plate, an increase in the weight of the metal box and an increase in manufacturing cost can be prevented.

  In the manufacturing method of the metal box body, a bending boundary portion is formed by bending at a boundary portion between the bottom portion and the side wall portion, and both the end portion of the bottom portion and the end portion of the side wall portion are aligned to form a plane. A superposed portion formed by overlapping is formed, and the superposed portion is welded to form a weld boundary portion by a lip joint at a boundary portion between the bottom portion and the side wall portion. According to the manufacturing method of the metal box body, among the boundary portion between the bottom and the side wall, the weld boundary is a lip joint, so compared to the case of welding with a corner joint, a butt joint or a lap joint, As a result, it is possible to manufacture a metal box having high weld quality at the weld boundary and high reliability in terms of airtightness. Furthermore, since the shape of the weld joint at the weld boundary between the bottom and the side wall is an edge joint, the welding operation is relatively easy, so the yield is good and the productivity is excellent.

It is a bottom side perspective view of a metal box in Example 1. (A) is the partial cross-section enlarged view in the AA line position of the recessed part after the superposition | polymerization part formation preparation process in Example 1, and a bending process. (B) is the fragmentary sectional enlarged view in the AA line position of the recessed part after the welding process in Example 1. FIG. It is a flowchart which shows the manufacturing process of the metal box body in Example 1. FIG. It is a perspective view of the expansion body in the expansion body formation process in Example 1. FIG. 5 is a partially enlarged plan view of FIG. 4 in the first embodiment. It is a perspective view of the expansion body in the superposition part formation preparation process in Example 1. 7 is a cross-sectional view corresponding to the BB position in FIG. It is a perspective view of the expansion body in the bending process in Example 1. It is a bottom side perspective view of the metal box in Example 2. In Example 2, it is a perspective view of the expansion body.

  The material forming the metal box is a metal material, and can be, for example, stainless steel, steel, aluminum, aluminum alloy, titanium, or the like. The forming material can be appropriately selected in consideration of the properties of the contents to be stored in the metal box, the use environment of the metal box, the formability of the forming material, and the like. For example, when used as a battery case, stainless steel can be employed in consideration of corrosion resistance and weldability.

  The thickness of the metal material forming the metal box is not particularly limited, but may be about 0.1 mm to about 2.0 mm, preferably about 0.1 mm to about 0.8 mm. In this case, the weight of the metal box can be reduced while maintaining the airtightness of the welded portion.

  The outer shape of the metal box is not particularly limited, and the shape of the bottom is a rectangle, an ellipse, a shape in which the short side of the rectangle is arcuate, or a shape in which the corners of the rectangle are rounded, etc. Can be made to stand on the outer periphery of the bottom.

  In the metal box, the length of the weld boundary portion may be shorter than the length of the bent boundary portion. In this case, since the length of the weld boundary portion can be relatively shortened at the boundary portion between the bottom portion and the side wall portion, the reliability of the airtightness of the metal box is further increased. Furthermore, since the welding length is shortened, the welding work is reduced, and the effect of achieving excellent productivity can be obtained. For example, the outer shape of the metal box is a shape in which the short side of the bottom is sufficiently short with respect to the longitudinal direction of the bottom, and the boundary in the longitudinal direction is the bent boundary between the boundary between the bottom and the side wall. Since the welding length can be shortened if the short-side boundary portion is a welding boundary portion, the reliability of the metal box can be further improved in terms of airtightness.

  In the metal box, the overlapping portion is formed with a standing wall by being deformed so that a concave portion is formed in at least one of the bottom portion and the side wall portion, and the standing wall is at least a part of the overlapping portion. Can be formed. In this case, the vertical wall surely overlaps the overlapping portion in a planar shape, so that welding by the helicopter joint at the weld boundary is reliably performed, and the reliability of the welded portion is further enhanced. The recessed portion may be formed only on one of the bottom and the side wall, or may be formed on both the bottom and the side wall. The recessed portion can be formed by drawing or bending. Among these, it is preferable to form by drawing. This is because it can be easily formed with high shape accuracy.

  In the metal box, the recessed portion may be provided at the bottom. In this case, the concave portion is formed at the bottom, thereby preventing the weld bead that may occur at the weld boundary from bulging outward from the bottom surface of the metal box. Thereby, stability when installing the said metal box body increases.

  In the metal box, the side wall includes a pair of first side walls facing each other by forming a bent boundary with the bottom, and a pair of second side walls facing each other by forming a welding boundary with the bottom. The first side wall and the second side wall are alternately provided so as to be adjacent to each other, and the boundary portion between the first side wall and the second side wall is formed by bending both, and is intermediate between the second side wall and the second side wall. The part is formed with a side wall welded portion formed by welding one end and the other end of the metal plate along the standing direction of the side wall so that the side wall is cylindrical. It can be. In this case, since the end of the side wall welded portion that welds the side wall portions does not coincide with the end of the weld boundary between the bottom portion and the side wall portion, avoid poor welding at the end of the side wall welded portion. Can do. Thereby, the reliability of a welding part increases.

  For example, the side wall welded portion may be formed along the standing direction of the side wall portion at the center of the second side wall portion. In this case, since the shapes of the portions that are bent from the pair of first side wall portions to form the second side wall portions are the same, the shape of the developed body of the metal box is based on the center of the bottom portion. It can be a symmetrical shape. Thereby, in the manufacturing process of the metal box, the orientation of the deployment body when the deployment body is set on a press machine or the like for bending or drawing may be different by 180 degrees. There are few processing restrictions, such as setting the back and front of the body upside down, and the degree of freedom in manufacturing process design is improved.

  Moreover, the said side wall weld part follows the standing direction of a side wall part in the position close | similar to the one side of the bending boundary part of a 1st side wall part and a 2nd side wall part so that it may shift from the center of a 2nd side wall part. It can also be formed as follows. In this case, when performing another processing on the central region of the second side wall portion, it is possible to avoid the interference with the side wall welded portion and secure a wide processing portion.

  In the manufacturing method of the metal box, the length of the weld boundary in the welding process may be shorter than the length of the bending boundary formed in the bending process. In this case, since the length of the weld boundary portion can be relatively shortened at the boundary portion between the bottom portion and the side wall portion, it is possible to manufacture a metal box with higher reliability of airtightness. Furthermore, since the welding length can be shortened, the welding operation is reduced, and the effect of achieving excellent productivity can be obtained.

  In the metal box manufacturing method, in the superposed part formation preparation step, a standing wall is formed by forming a recessed part in at least one of the bottom part or the side wall part, and in the bending step, the standing wall becomes the superposed part. The unfolded body can be bent so as to form a part of In this case, the standing wall ensures that the overlapping portion is planarly overlapped, so that the shape of the welded joint between the bottom and the side wall becomes an edge joint, and the weld quality at the weld boundary is improved. , Increase the reliability of airtightness. In the overlapped part formation preparation step, the recessed part may be formed only on one of the bottom part and the side wall part, or the recessed part may be formed on both the bottom part and the side wall part.

  In the metal box manufacturing method, in the development body forming step, a bottom corresponding part corresponding to the bottom part, a first side wall corresponding part and a second side wall corresponding part corresponding to the side wall part, A pair of first side wall corresponding parts formed across the bottom corresponding part, and a pair of first side wall corresponding parts in a direction intersecting a boundary portion between the bottom corresponding part and the first side wall corresponding part. A second side wall portion corresponding portion formed to extend to both ends, and in the bending step, the second side wall portion corresponding portion is set to the first side wall portion corresponding portion, respectively. Are bent in the standing direction of the side wall portion, and the first side wall portion corresponding portion is bent at the boundary portion with the bottom portion corresponding portion to form the bent boundary portion, and the pair of first 1 Face the corresponding side wall part The overlapping portion is formed and the second side wall corresponding portions are butted or overlapped with each other, and in the welding process, the side wall portions are matched or overlapped so as to form a cylindrical shape. The parts can be welded together to form a side wall weld.

  In this case, the end of the side wall welded portion and the end of the weld boundary portion between the bottom and the side wall portion do not coincide with each other, so that poor welding at the end of the side wall welded portion can be avoided. As a result, it is possible to provide a metal box with a highly reliable welded portion.

Example 1
As shown in FIG. 1, the metal box 1 of the embodiment has a substantially rectangular parallelepiped shape, and includes a bottom portion 10, a first side wall portion 11, and a second side wall portion 12. The opposite side of the bottom 10 is open and an opening 13 is formed. As for the outer shape of the metal box 1, the short direction (Y direction) is sufficiently short with respect to the longitudinal direction (X direction) of the bottom portion 10, and the depth direction (Z direction) thereof is short with respect to the short direction of the bottom portion 10. The shape is large enough.

  The metal box 1 is made of austenitic stainless steel (SUS304). The bottom portion 10 has a rectangular bottom surface 10 a and two deformation portions 20. The bottom surface 10a is rectangular, and the deformable portions 20 are provided on both short side portions 10c of the bottom surface 10a. Then, both long side portions 10b of the bottom surface 10a and a later-described edge joint weld portion 24 formed on the outer edge of the deformable portion 20 form the outer peripheral edge of the bottom portion 10.

  First side wall portions 11 are erected on both long side portions 10b of the bottom surface 10a. A boundary portion (long side portion 10b) between the bottom portion 10 and the first side wall portion 11 is formed by bending the first side wall portion 11 in the standing direction (Z direction). The first side wall portion 11 is formed in a pair so as to face each other in both of the long side portions 10b. The first side wall portion 11 has a rectangular flat plate shape and forms a long wall surface of the metal box 1.

  On the other hand, as shown in FIG. 1, the second side wall portion 12 is erected on the outer edge of the deformable portion 20 (the portion where the edge joint weld portion 24 is formed). The second side wall portions 12 are provided as a pair so as to face each other, and the first side wall portions 11 and the second side wall portions 12 are alternately provided so as to be adjacent to each other. The side wall 11 is bent and formed. The second side wall portion 12 is formed by welding with the bottom portion 10 at the outer edge of the deformable portion 20. A side wall welded portion 12 b parallel to the Z direction is formed at the intermediate portion of the second side wall portion 12. The second side wall portion 12 forms a short wall surface of the metal box 1.

As shown in FIGS. 2 (a) and 2 (b), the bottom portion 10 is provided with a recessed portion 21 that is recessed in the inner space side of the metal box 1 in the deformable portion 20. The recessed portion 21 forms a tapered portion 23 having a gently inclined surface continuous with the bottom surface 10a, and a standing wall 22 rising in parallel with the Z direction. In the deformed portion 20, the standing wall 22 and the second side wall portion 12 are overlapped in a planar shape with the end portion 22 a of the standing wall 22 and the end portion 12 a of the second side wall portion 12 aligned to form the overlapping portion 25. Has been. That is, the back surface of the upright wall 22 (the surface that is continuous with the inner space side surface of the metal box 1 at the bottom portion 10) and the rear surface of the second side wall portion 12 (the inner space surface of the metal box body 1). Opposite and close to each other in a substantially parallel state. In the overlapping portion 25, the end portion 22 a of the standing wall 22 and the end portion 12 a of the second side wall portion 12 are welded by the edge joint, and the edge joint welded portion 24 is formed along the outer edge of the deformable portion 20.
The boundary portion between the bottom portion 10 and the side wall portions (the first side wall portion 11 and the second side wall portion 12) includes a bent boundary portion (long side portion 10b) formed by bending the bottom portion 10 and the first side wall portion 11, and the bottom portion 10. And the second side wall portion 12 are welded boundary portions (edge joint weld portions 24).

Next, a method for manufacturing the metal box 1 will be described.
As shown in FIG. 3, the manufacturing method 101 of the metal box 1 includes a development body forming step S1, a superposition part forming preparation step S2, a bending step S3, and a welding step S4.

  First, in the development body forming step S1, a flat development body 100 is formed as shown in FIG. 4 by punching a single metal plate with a press. The formation method of the expansion | deployment body 100 is not limited to this, Laser cutting, wire electric discharge machining, etc. can also be employ | adopted. The metal plate which is a material for forming the development body 100 is a flat plate made of austenitic stainless steel (SUS304), and the plate thickness is about 0.5 mm. The unfolded body 100 includes a bottom corresponding portion 110 corresponding to the bottom portion 10 of the metal box 1, a first side wall corresponding portion 111 formed in a pair with the bottom corresponding portion 110 interposed therebetween, and the pair of first side wall portions. A second side wall corresponding part 112a formed so as to extend at both ends in the direction intersecting the boundary part (long side part 10b) between the bottom corresponding part 110 and the first side wall corresponding part 111 in the corresponding part 111, 112b.

  As shown in FIG. 4, the bottom corresponding portion 110 includes a bottom surface corresponding portion 110 a corresponding to the bottom surface 10 a and a deformable portion corresponding portion 120 corresponding to the deformable portion 20. The shape of the bottom surface corresponding part 110a is a rectangle. The deformable portion corresponding portion 120 extends on the pair of short sides of the bottom surface corresponding portion 110a. As shown in FIG. 5, the deformable portion corresponding portion 120 has a substantially rectangular shape and bulges in the short side direction of the bottom surface corresponding portion 110a as the distance from the bottom surface corresponding portion 110a increases.

  As shown in FIG. 4, the shape of the first side wall corresponding part 111 is a rectangle, and the longitudinal direction thereof coincides with the longitudinal direction of the bottom corresponding part 110. The shapes of the second side wall corresponding parts 112a and 112b are both rectangular, and the longitudinal direction thereof is the short side of the first side wall corresponding part 111 (both ends in the direction intersecting the long side part 10b which is the boundary part). Along. Further, as shown in FIG. 5, in the second side wall portion corresponding portions 112 a and 112 b, the side of the second side wall portion corresponding portions 112 a and 112 b facing the deformable portion corresponding portion 120 is cut out along the outer edge of the deformable portion corresponding portion 120. A notch 112c is formed.

  Next, in the overlapped part formation preparation step S2, the recessed part 21 is formed as shown in FIG. 6 by drawing the deformed part corresponding part 120 of the developed body 100 shown in FIG. Specifically, the drawing processing is performed by pressing a jig having a shape corresponding to the drawing processing portion 121a against the rectangular drawing processing portion 121a that is slightly smaller than the outer shape of the deforming portion corresponding portion 120 shown in FIG. The drawing process may be performed once or may be performed in a plurality of times. The position of the side on the center side of the bottom surface corresponding portion 110a of the drawing portion 121a is closer to the center side of the bottom surface corresponding portion 110a than the lower end of the notch portion 112c by a distance d (about 1.5 mm). The distance d can be appropriately changed according to the shape of the metal box 1 and the material and thickness of the forming material. Moreover, although the said distance d is not specifically limited, For example, it can also be set as the value between 0.5 mm-3.0 mm.

  As shown in FIGS. 6 and 7, the recessed portion 21 is formed by drawing. Thereby, the taper part 23 which has the gentle inclined surface (bottom surface of the recessed part 21) continuous with the bottom face corresponding part 110a is formed. At the same time, the standing wall 22 is formed in a portion of the outer periphery of the recessed portion 21 excluding a portion continuous with the bottom surface corresponding portion 110a. The standing wall 22 is a wall that rises in parallel with the standing direction (Z direction) of the first side wall portion 11 and is substantially perpendicular to the bottom surface corresponding portion 110a.

  Subsequently, in the bending step S3, first, as shown in FIG. 8, the second side wall portion corresponding portions 112a and 112b are bent in the standing direction (Z direction). Thereafter, the first side wall portion corresponding portion 111 is bent in the standing direction (Z direction), and as shown in FIG. 2A, the end portion 22a of the standing wall 22 and the second side wall portion corresponding portion 112a ( 112b) and the end portion 12a are aligned so that the height position in the Z direction in the cross section is the same position, and the standing wall 22 and the second side wall portion corresponding portion 112a (112b) are overlapped in a planar shape to overlap the overlapping portion. 25 is formed. At the same time, as shown in FIG. 1, the second side wall portion corresponding portions 112a and 112b are brought into contact with each other in the side wall welded portion 12b. The bending step S3 can be performed by bending with a press. Further, as shown in FIG. 5, the position of the side on the center side of the bottom surface corresponding portion 110a of the drawing portion 121a is the center of the bottom surface corresponding portion 110a by a distance d (about 1.5 mm) from the lower end of the notch portion 112c. 2A. As shown in FIG. 2A, the metal plate as the forming material is bent at about 180 degrees at both ends of the bending boundary portion (long side portion 10b) by the bending step S3. A folded portion 26 is formed.

  Next, in the welding step S4, the second side wall portion corresponding portions 112a and 112b in a butted state are welded at the side wall welded portion 12b. The side wall welded portion 12 b is formed in a straight line parallel to the Z direction from the bottom portion 10 to the opening portion 13 in the intermediate portion of the second side wall portion 12. In this example, the side wall welded portion 12 b is provided in the center of the second side wall portion 12 along the Z direction. The welding can be performed by TIG welding, plasma welding, laser welding, or the like. In this example, welding was performed by TIG welding.

  Here, in the welding of the second side wall portion corresponding portions 112a and 112b, a welding defect may occur due to dripping of the weld metal at the bottom 10 side end portion or the opening portion 13 side end portion of the side wall welded portion 12b. In such a case, an extension part (end tab, not shown) obtained by extending the forming material of the metal box 1 is provided in advance at both ends of the side wall welded part 12b, and the side wall welded part 12b is subjected to the welding. After the end tabs are welded together, the end tabs are cut off, thereby preventing welding defects from occurring in the side wall welded portions 12b.

  Thereafter, in the overlapping portion 25 shown in FIG. 2A, the end portion 22a of the standing wall 22 and the end portion 12a of the second side wall portion 12 (112a, 112b) are welded, as shown in FIG. 2B. A lip joint weld 24 is formed. The welding can be performed by TIG welding, plasma welding, laser welding, or the like. In this example, similarly to the welding of the side wall welded portion 12b, welding was performed by TIG welding. As shown in FIG. 2A, in the state in which the overlapping portion 25 is formed, the end portion 22a of the standing wall 22 and the end portion 12a of the second side wall portion 12 that are at the same height are welded by an edge joint. As a result, as shown in FIG. 2B, the edge joint welded portion 24 is formed across the both ends of the standing wall 22 and the second side wall portion 12. In addition, as shown in FIG. 1, welding of the superposition | polymerization part 25 is performed by making one folding part 26 into a starting position, and making the other folding part 26 into an end position.

  When the metal box 1 manufactured by the manufacturing method 101 is closed by the predetermined method and the airtightness of the metal box 1 is inspected by the He leak test, the metal box 1 has a sufficiently high airtightness. It was confirmed.

The effect of the metal box 1 manufactured by the manufacturing method 101 will be described.
In the welding step S4, the end portion 22a of the standing wall 22 and the end portion 12a of the second side wall portion 12 are welded by the edge joint in the welding portion S4 to form the edge joint weld portion 24. The Thereby, high weld quality is obtained at the weld boundary portion (edge joint weld portion 24) between the bottom portion 10 and the second side wall portion 12, and as a result, the metal box 1 having high reliability with respect to airtightness is provided. Is done. Furthermore, since both ends 12a and 22a are welded by the edge joint in the overlapping portion 25, it can be reliably welded also by TIG welding. Therefore, compared with the case where it welds by laser welding etc., the metal box 1 which has high reliability at low cost can be manufactured.

  Further, since the standing wall 22 and the second side wall portion 12 are welded by the edge joint in the overlapping portion 25, even if it is a thin stainless steel plate having a thickness of about 0.5 mm as in this example, the weld boundary portion (edge joint) The airtightness of the welded portion 24) can be sufficiently secured. Thereby, the metal box 1 is reduced in weight while maintaining the airtightness of the weld boundary portion (edge joint weld portion 24).

  Furthermore, as shown in FIG. 1, the outer shape of the metal box 1 is sufficiently short in the short direction (Y direction) with respect to the longitudinal direction (X direction) of the bottom portion 10, and its depth direction (Z direction) is The shape is sufficiently larger than the width direction of the bottom 10. And the 1st side wall part 11 used as the long wall surface in the said bending process S3 is bend | folded from the bottom part 10, the bending boundary part (long side part 10b) is formed, and the 2nd side wall part 12 used as the short wall surface in the said welding process S4. And the bottom 10 are edge joint welded to form a weld boundary (edge joint weld 24). Thereby, since welding length can be shortened significantly compared with the case where a bending boundary part is also welded, the reliability about the airtightness of the metal box 1 further increases. Further, since the welding length is significantly shortened, the welding work is reduced and the productivity is excellent. In addition, as described above, the metal box 1 is sufficiently large in the depth direction (Z direction) as compared with the short direction (Y direction), so that it is difficult to form the metal plate only by deep drawing, According to the manufacturing method 101 of this example, the metal box 1 can be easily formed.

  In addition, since welding of the overlapping portion 25 is performed with one of the folded portions 26 as a start position and the other folded portion 26 as an end position, the welding start position and the end position are not formed by welding end faces but by a forming material. This is the welding of a portion where a certain metal plate is bent about 180 degrees. This effectively prevents welding defects from occurring at the welding start and end positions. In addition, in this example, although the folding part 26 was provided, it is not restricted to this, In FIG. 5, the position of the side by the side of the bottom face corresponding part 110a of the drawing process part 121a in the longitudinal direction of the bottom face corresponding part 110a is cut. The folding position 26 may not be provided at the same position as the lower end of 112c (that is, the distance d is 0). In this case, welding is performed under conditions where no welding defect occurs at the start position and end position of the overlap portion 25 welding.

  Further, in this example, as shown in FIGS. 5 and 6, a notch 112c is formed on the recessed portion 21 side of the second side wall corresponding portions 112a and 112b, and as shown in FIG. The part 12a is located inside the bottom surface 10a (inner side of the metal box 1). Further, the end 22a of the standing wall 22 is also located on the inner side of the bottom surface 10a. Thereby, as shown in FIG.2 (b), the edge joint welding part 24 formed by welding the both ends 12a and 22a will also be located inside the bottom face 10a. As a result, since the edge joint welded portion 24 does not interfere with the placement surface when the metal box body 1 is placed, the placement state of the metal box body 1 may become unstable by the edge joint welded portion 24. Is prevented.

  Further, the side wall welded portion 12 b is formed at an intermediate portion of the second side wall portion 12. Thereby, the edge part by the side of the bottom part 10 of the side wall welding part 12b will be located in the intermediate part of the welding part (edge joint welding part 24) of the bottom part 10 (standing wall 22) and the 2nd side wall part 12. FIG. Thereby, since the edge part by the side of the bottom part 10 of the side wall welding part 12b and the edge part of the edge joint welding part 24 do not correspond, the reliability of both welding parts increases.

  Furthermore, the side wall welded portion 12 b is formed along the standing direction of the second side wall portion 12 in the center of the second side wall portion 12. Thereby, the shape of the part (2nd side wall part corresponding | compatible part 112a, 112b) bent from the pair of 1st side wall parts 11 and forming the 2nd side wall part 12 is respectively the same, and the shape of the expansion body 100 is the same. The shape is point-symmetric with respect to the center of the bottom 10. Thereby, in the superposition | polymerization part formation preparation process S2, the direction of the expansion | deployment body 100 at the time of setting the expansion | deployment body 100 to a press machine for drawing processing may differ 180 degree | times, and the reverse side of the expansion | deployment body 100 is reversed. There are few restrictions on processing, such as setting it to, and the degree of freedom in process design of the overlap portion formation preparation step S2 is improved.

  In this example, in the overlapped part formation preparation step S2, the standing wall 22 is raised until it becomes parallel to the standing direction (Z direction). 22 may be inclined. In this case, when forming the overlapping portion 25 in the bending step S3, the second side wall portion corresponding portions 112a and 112b are pressed against the inclined standing wall 22 so that at least a part of the standing wall 22 is set in the standing direction (Z It can be raised until it is parallel to (direction), and both can be overlapped in a planar shape. If it does in this way, in the overlap part 25, the clearance gap between the standing wall 22 and 2nd side wall part corresponding | compatible part 112a, 112b can be eliminated, and the reliability of the edge joint welding part 24 increases.

  In this example, after the overlapping portion formation preparation step S2, in the bending step S3, the second side wall portion corresponding portions 112a and 112b are bent in the standing direction (Z direction), and then the first side wall portion corresponding portion 111 is raised. Although it bent in the installation direction (Z direction), it is not limited to this. For example, the second side wall portion corresponding portions 112a and 112b are bent in the standing direction (Z direction) before the overlap portion formation preparation step S2, and then the overlap portion formation preparation step S2 is performed. The one side wall corresponding portion 111 may be bent in the standing direction (Z direction). In addition, in the overlapping portion formation preparation step S2, the second side wall corresponding portions 112a and 112b are bent in the standing direction (Z direction) simultaneously with the formation of the recessed portion 21, and then in the bending step S3, the first side wall is formed. The part corresponding part 111 may be bent in the standing direction (Z direction). In either case, the same effects as the present example are achieved.

  In this example, in the manufacturing method 101 of the metal box 1, in the welding step S <b> 4, after welding the side wall welded part 12 b, the overlapped part 25 is welded to form the edge joint welded part 24, but the present invention is not limited thereto. The side wall welded portion 12b may be welded after the overlapped portion 25 is welded to form the edge joint welded portion 24. Even in this case, the same operational effects as the present example are obtained.

Moreover, in this example, although the deformation | transformation part 20 (concave part 21) was provided in the bottom part 10, it is not limited to this, You may provide a deformation | transformation part (concave part) in a 2nd side wall part. Even in this case, the same effects as the metal box 1 of the first embodiment are obtained.
In this example, other members such as a lid member may be attached to the opening 13. Other members such as a lid member can be attached separately from the metal box 1 or can be formed integrally with the metal box 1.

(Example 2)
As shown in FIG. 9, the metal box 2 that is another embodiment has a side wall welded portion 212 c not at the center of the second side wall portion 212, but closer to the boundary portion between the second side wall portion 212 and the first side wall portion 11. Is formed. As shown in FIG. 10, the development body 200 of the metal box body 2 is formed so that the second side wall portion corresponding portion 212a extends at both ends of the first side wall portion corresponding portion 111a, and corresponds to the first side wall portion. The second side wall corresponding part 212b is formed to extend at both ends of the part 111b, and the second side wall corresponding part 212a is longer than the second side wall corresponding part 212b. In addition, the same code | symbol is attached | subjected to the component etc. equivalent to the metal box 1 of Example 1, and the description is abbreviate | omitted.

  The metal box 2 is formed by the same manufacturing process as that of the metal box 1 of the first embodiment. However, in the bending step S3, the second side wall corresponding parts 212a and 212b are together with the standing wall 22 as described above. It is bent along the standing wall 22 so as to form the overlapping portion 25. And the 2nd side wall part corresponding | compatible part 212a, 212b will be in the state mutually faced | matched. And in welding process S4, the 2nd side wall part corresponding | compatible parts 212a and 212b are welded mutually, and the side wall weld part 212c is formed. In the overlap portion 25, the edge joint weld portion 24 is formed as described above.

  According to this example, since the side wall welded portion 212c is formed near the boundary portion between the second side wall portion 212 and the first side wall portion 11, interference with the side wall welded portion 212c is avoided to avoid the second side wall portion 212c. It is possible to secure a wide processing portion for performing another processing in the central region. Also in the metal box 2 which is another Example, there exists an effect equivalent to the metal box 1 of Example 1.

DESCRIPTION OF SYMBOLS 1, 2 Box 10 Bottom part 11 1st side wall part 12, 212 2nd side wall part 12b, 212c Side wall welding part 20 Deformation part 21 Recessed part 22 Standing wall 24 Welding boundary part (edge joint welding part)
25 Superposition part 100 Deployment body 110 Bottom part corresponding part 111, 111a, 111b First side wall part corresponding part 112a, 112b, 212a, 212b Second side wall part corresponding part

Claims (2)

A metal box formed by forming a bottom part and a side wall part erected from the outer peripheral edge of the bottom part from a single metal plate,
The bottom has a square shape,
The side wall portion is welded at two side wall welded portions that form a straight line parallel to the standing direction, and has a quadrangular cylindrical shape having four side surfaces,
The said two side wall welding part is a metal box which is located in the position inside one side of the said side wall part while being provided in any one side surface of the said side wall part. The boundary part between the bottom part and the side wall part consists of a bending boundary part formed by bending both, and a welding boundary part formed by welding the two together.
The metal box body according to claim 1, wherein the two side wall welded portions are in contact with the weld boundary portion at a position different from an end portion of the weld boundary portion.

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