Shelf plate

Abstract

To suppress an increase in cost and cycle time in a shelf board.SOLUTION: The shelf plate 12 includes a base plate 13 and a top plate 14. The substrate 13 is a flat plate along the width direction and the depth direction, and a convex portion 21 that protrudes in the thickness direction and extends in the width direction is formed. The top plate 14 is a flat plate along the width direction and the depth direction, is superimposed on the upper surface of the substrate 13, and is spot-welded to the substrate 13 at a plurality of welding points 23 disposed only on both end sides in the width direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a shelf board. [Background technology]

[0002] The lightweight metal panel described in Patent Document 1 is constructed by overlapping a base plate on which numerous protrusions are formed by embossing with a smooth top plate, and joining the top surfaces of the protrusions by spot welding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-307117 Summary of the Invention [Problem to be solved by the invention]

[0004] The greater the number of welding points used to join the base plate and the top plate, the greater the cost and cycle time. An object of the present invention is to suppress increases in costs and cycle time for shelf boards. [Means for solving the problem]

[0005] A shelf board according to one aspect of the present invention includes a base plate and a top plate. The base plate is a flat plate extending in the width and depth directions, and has a convex portion extending in the width direction and convex in the thickness direction. The top plate is a flat plate extending in the width and depth directions, and is placed on top of the base plate and spot-welded to the base plate at multiple welding points located only on both ends in the width direction. [Effects of the Invention]

[0006] According to the present invention, the welding points are limited to only both ends in the width direction, so that increases in costs and cycle time can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing a showcase. [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 10 is a diagram showing the comparison results. [Figure 7] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual product. Furthermore, the following embodiments exemplify devices and methods for embodying the technical concept of the present invention, and are not intended to limit the configuration to those described below. In other words, the technical concept of the present invention can be modified in various ways within the technical scope described in the claims.

[0009] <<Embodiment>> "composition" In the following description, the three mutually orthogonal directions are referred to as a width direction, a depth direction, and a vertical direction. The width direction and the depth direction are horizontal directions. FIG. 1 is a diagram showing a showcase 11. As shown in FIG. Here, the showcase 11 is shown as seen from one side in the width direction. The showcase 11 is a display shelf for displaying products, and has a plurality of shelves 12 arranged vertically and fixed to a frame. The shelves 12 are formed as flat plates that extend in the width and depth directions, but may also be inclined so that the front end in the depth direction is downward.

[0010] FIG. 2 is a diagram showing the shelf board 12. As shown in FIG. The shelf board 12 is formed by joining a base plate 13 and a top plate 14. Here, the separated base plate 13 and top plate 14 are shown as viewed from one side in the width direction, one side in the depth direction, and from above in the up-down direction. The base plate 13 is a flat steel plate extending in the width and depth directions, and is formed into a rectangle with the width direction as the longitudinal direction when viewed from the top and bottom. The base plate 13 has a protrusion 21 and a hole 22 formed therein. The top plate 14 is a flat steel plate that extends in the width and depth directions, and has the same external shape as the base plate 13 when viewed from the top and bottom. It is placed on top of the base plate 13 and spot-welded to the base plate 13 at multiple welding points.

[0011] FIG. 3 is a diagram showing the substrate 13. As shown in FIG. (a) in the figure shows the state of the substrate 13 as viewed from above in the vertical direction, and (b) in the figure shows the state of the AA cross section of the substrate 13, which passes through the center in the width direction and is along the depth direction and vertical direction, as viewed from one side in the width direction. The protrusions 21 are beads that protrude downward in the vertical direction and extend in the width direction, and are formed in three locations spaced apart in the depth direction. The protrusions 21 are provided to increase the bending rigidity when the substrate 13 is subjected to an out-of-plane load, and are formed by drawing. The protrusions 21 extend to both sides of the substrate 13 in the width direction. When viewed in the width direction, the protrusions 21 have a cross-sectional shape that resembles a bathtub curve. The holes 22 are elongated holes extending in the width direction and are formed in two locations between the protrusions 21 aligned in the depth direction. The holes 22 are provided to prevent wrinkles and warping when the protrusions 21 are formed, and are formed by punching. Therefore, the two holes 22 are first formed in the substrate 13, and then the protrusions 21 are formed in a subsequent process.

[0012] FIG. 4 is a diagram showing the shelf board 12. As shown in FIG. (a) in the figure shows the shelf board 12, with the base plate 13 and top plate 14 joined together, as viewed from above in the vertical direction. The base plate 13 and top plate 14 are spot-welded at multiple welding points 23, as shown by the hatching. The welding points 23 are located only on both ends in the width direction, and more specifically, on both sides in the depth direction and in the center, for a total of six locations, on both sides in the width direction of the protrusion 21. The shelf board 12, with the base plate 13 and top plate 14 joined together, will be painted in a subsequent process, so the welding points 23 will be inconspicuous and will not impair the design. (b) in the figure shows the BB cross section, which passes through the center of the width direction and is along the depth direction and the up-down direction, of the shelf board 12 in which the base plate 13 and the top plate 14 are joined, as viewed from one side in the width direction. By overlapping and joining the top plate 14 to the top surface of the base plate 13, the back side (recess) of the protrusion 21 and the hole 22 are covered, and a flat upper surface is formed.

[0013] Example Next, an example will be described. FIG. 5 is a diagram showing an embodiment. Figure (a) shows an example in which four welding points are placed at the four corners of the shelf 12, for a total of four points. Figure (b) shows an example in which six welding points are placed at three points lined up in the depth direction on both sides of the width. Figure (c) shows an example in which eight welding points are placed at four corners of the shelf 12 and four points lined up in the depth direction at the center of the width. Figure (d) shows an example in which eight welding points are placed at four points lined up in the depth direction on both sides of the width. Figure (e) shows an example in which 12 welding points are placed at four points lined up in the depth direction on both sides of the width and four points lined up in the depth direction at the center of the width. Figure (f) shows an example in which 20 welding points are placed at four points along the depth direction and five points along the width. Figure (g) shows an example in which 36 welding points are placed at four points along the depth direction and nine points along the width. The welding points are all arranged in areas that avoid the protrusions 21 and holes 22.

[0014] FIG. 6 is a diagram showing the results of comparing the amount of deflection when a load is applied to the shelf board 12 before the holes 22 are drilled. The amount of deflection when a load is applied to the shelf 12 is shown for each of the examples (a) to (g) in Figure 6. The smaller the amount of deflection, the higher the rigidity of the shelf 12. In the examples (a) with four welding points and (c) with eight welding points, the amount of deflection was 4.5 mm or more, indicating relatively low rigidity. On the other hand, in the examples (b) with six welding points, (d) with eight welding points, (e) with 12 welding points, (f) with 20 welding points, and (g) with 36 welding points, the amount of deflection was approximately 4.2 mm, indicating relatively high rigidity. Although the difference was small, the amount of deflection was the lowest in the example (b). Therefore, it was found that the example (b) with six welding points could minimize the number of welding points while maintaining the necessary rigidity. Note that after the holes 22 are formed, the rigidity increases at approximately the same rate for each of the examples (a) to (g).

[0015] <<Action and Effect>> Next, the main effects of the embodiment will be described. The shelf board 12 includes a base plate 13 and a top plate 14. The base plate 13 is a flat plate extending in the width and depth directions, and is formed with a protrusion 21 that is convex in the thickness direction and extends in the width direction. The top plate 14 is a flat plate extending in the width and depth directions, and is placed on top of the base plate 13 and spot-welded to the base plate 13 at a plurality of welding points 23 located only on both ends in the width direction. In this way, because the welding points 23 are limited to only both ends in the width direction, increases in cost and cycle time can be suppressed.

[0016] The welding points 23 are arranged only on both sides in the width direction of the protrusion 21. This prevents the welding points 23 from overlapping the protrusion 21, and allows the necessary joining strength to be achieved. The welding points 23 are arranged only on both sides in the width direction, both sides in the depth direction, and in the center. By arranging the welding points 23 in a total of six locations, the number of welding points 23 can be minimized while ensuring the necessary rigidity. The protrusions 21 are convex downward in the thickness direction. This allows the substrate 13 and the top plate 14 to be joined in an area that avoids the protrusions 21, improving the degree of freedom in the placement of the welding points. If a protrusion that is convex upward in the thickness direction is formed, the welding points will be provided on the top surfaces of the protrusions, reducing the degree of freedom in the placement of the welding points.

[0017] Holes 22 are formed in the substrate 13 so as to penetrate through the substrate 13 in the thickness direction, thereby preventing defects such as wrinkles and warping from occurring in the substrate 13 when the protrusions 21 are formed by drawing. The holes 22 are formed on both sides or one side in the depth direction of the protrusions 21. This effectively prevents defects such as wrinkles and warping from occurring in the substrate 13 when the protrusions 21 are formed by drawing. Hole 22 is an elongated hole extending in the width direction, which effectively prevents defects such as wrinkles and warpage from occurring in substrate 13 when forming protrusions 21 by drawing.

[0018] <<Variation>> In the embodiment, the hole 22 is an elongated hole extending in the width direction, but the hole 22 is not limited to this and may be, for example, a plurality of holes arranged in the width direction. FIG. 7 is a diagram showing a modified example. (a) in the figure shows the substrate 13 as viewed from one side in the width direction, one side in the depth direction, and from above in the vertical direction. (b) in the figure shows the substrate 13 as viewed from above in the vertical direction. Holes 31 are formed in the substrate 13. The holes 31 are multiple round holes lined up in the width direction, and are formed in a total of six locations between the protrusions 21 lined up in the depth direction: two locations along the depth direction, and three locations on both sides and in the center in the width direction. This makes it possible to prevent defects such as wrinkles and warping from occurring in the substrate 13 when the protrusions 21 are formed by drawing.

[0019] Although the present invention has been described above with reference to a limited number of embodiments, the scope of the invention is not limited thereto, and modifications of the embodiments based on the above disclosure will be obvious to those skilled in the art. [Explanation of symbols]

[0020] 11...showcase, 12...shelf board, 13...board, 14...top board, 21...projection, 22...hole, 23...welding point, 31...hole

Claims

1. a substrate that is a flat plate along the width direction and the depth direction and has a convex portion that is convex in the thickness direction and extends in the width direction; A shelf board characterized by comprising: a top plate that is a flat plate extending in the width and depth directions, which is placed on top of the base plate and spot-welded to the base plate at multiple welding points located only on both ends in the width direction.

2. The shelf board according to claim 1 , wherein the welding points are arranged only on both sides of the protrusion in the width direction.

3. 2. The shelf board according to claim 1, wherein the welding points are arranged only on both sides in the width direction and on both sides and the center in the depth direction.

4. The shelf board according to claim 1 , wherein the protrusions are protruded downward in the thickness direction.

5. The shelf board according to claim 1 , wherein the base plate has a hole formed therethrough in the thickness direction.

6. The shelf board according to claim 5, wherein the hole is formed on one or both sides of the protrusion in the depth direction.

7. 7. The shelf board according to claim 6, wherein the hole is an elongated hole extending in the width direction or a plurality of holes aligned in the width direction.

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