JPH07260163A - Connecting structure between plate materials - Google Patents

Abstract

PURPOSE:To provide a connecting structure between rigid plate materials finally without shaking preventing a reaction force due to a caulking force generated at the time of caulking. CONSTITUTION:A first plate material 20 has a folded part 22 folded from a front surface side to a rear surface side by 180 deg. with an opening edge 21 as a boundary. An end of the part 22 is connected to an end of a second plate material 30 by caulking. The part 22 has a reinforcing rib 24 protruding toward the rear surface side between an end 23 to be caulked and the edge 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between plate members in which a first plate member having an opening and a second plate member orthogonal to the plate member are joined. More specifically, the present invention relates to an improvement in joining a front plate and a top plate of an inner box used in a cooking appliance such as a microwave oven.

[0002]

Prior Art and Problems to be Solved by the Invention FIG.
5 shows cooking equipment such as a microwave oven, and FIG. 16 shows an inner box of the cooking equipment. The microwave oven 1 includes a main body 2 and a door 3. The main body 2 includes an inner box 4. In a cooking device such as a microwave oven, an inner box 4 is provided in order to effectively use heat and to prevent radio wave leakage. Therefore,
The main body 2 has a double structure.

As is apparent from FIG. 16, the inner box 4 includes a front plate 5 having an opening 5a, a cylindrical body 6 joined near the opening edge 5b of the front plate, and a rear end of the body 6. And a rear plate 7 joined to the.

FIG. 17 shows the joint between the front plate 5 and the top plate 6a of the body 6. As shown, the front plate 5 is
It is folded back to the back side with the opening edge 5b as a boundary. The top plate 6a of the tubular body portion 6 is joined to the back surface of the front plate 5 by spot welding at a position slightly above the folded-back portion of the front plate 5. The reason why the top plate 6a is joined at a position that is shifted upwards more than the opening edge 5b is to increase the internal volume of the refrigerator.

Conventionally, the front plate 5 and the top plate 6a of the inner box of the cooking appliance are used.
And were joined by spot welding, but this joining has the following problems. That is, when spot welding is performed, welding marks are left on the surface of the front plate 5, and the appearance is poor. Furthermore, the welding operation itself is extremely complicated.

FIG. 18 illustrates a joining structure that does not require welding work. The front plate 10 having the opening 11 has an opening edge 11
It has a folded-back portion 10a that is folded back 180 ° from the front surface side to the back surface side with a as a boundary. The tip of the folded-back portion 10a and the tip of the top plate 12 are joined by caulking. According to this structure, welding work becomes unnecessary, but on the other hand, the following problems occur.

FIG. 19 shows a state before caulking, and FIG. 20 shows a state when caulking.
As shown by the arrow A in FIGS. 19 and 20, when the tip portion of the folded-back portion 10a and the tip portion of the top plate 12 are fitted and caulked, the reaction force of the caulking force is shown at the time of caulking as shown in FIG. Due to the influence of the
a is bent. When the caulking force is released, the bent portion 10a is not warped and returns to the original state. However, this returning operation causes rattling in the joining of the plate materials at the caulking portion.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a joining structure between plate materials in which the caulking portion does not rattle.

Another object of the present invention is to provide a joining structure capable of preventing the plate material from warping due to the reaction force of the caulking force during the caulking process.

Still another object of the present invention is to provide a joining structure between plate materials capable of reducing the reaction force of the caulking force during caulking.

[0011]

SUMMARY OF THE INVENTION The present invention is a joining structure between plate members in which a second plate member having a positional relationship substantially orthogonal to a first plate member having an opening is joined. It is characterized by the following. In other words, the first plate member 18 is moved from the front surface side to the back surface side with the opening edge as a boundary.
It has a folded portion that is folded back by 0 °. The leading end of the folded portion and the leading end of the second plate member are joined by caulking. The folded-back portion is provided with a reinforcing rib protruding toward the back surface side between the tip end portion to be caulked and the opening edge.

According to the joining structure having the above structure, even if the reaction force of the caulking force acts on the folded-back portion during the crimping process, the reinforcing ribs prevent the bent-back portion from bending. Therefore,
No rattling occurs at the caulked joint.

According to a preferred embodiment, the reinforcing rib extends from the opening edge toward the tip. Further, the end portion on the tip end side of the reinforcing rib is sheared and separated from the folded portion.

The reaction force due to the caulking force does not pass through the shearing edge of the reinforcing rib. Therefore, the magnitude of the reaction force is reduced, and the bending of the folded portion is effectively prevented.

Further, according to a preferred embodiment of the present invention, the tip portion of the folded portion has a protruding piece protruding in a direction away from the opening edge. This protruding piece is joined to the second plate member by caulking. The reinforcing rib extends long from the opening edge toward the protruding piece.

In the above-mentioned preferred embodiment, the area where the reaction force due to the caulking force directly acts is the area where the protruding piece is formed. Therefore, as a whole, the reaction force acting on the folded portion is small. Further, since the reinforcing rib is provided in the region where the reaction force acts, the bending of the folded portion can be effectively prevented.

In the above preferred embodiment, more preferably, the edge of the reinforcing rib located on the protruding piece side is sheared and separated from the folded portion. The width dimension of the reinforcing rib viewed in the direction parallel to the opening edge is smaller than the width dimension of the protruding piece, and the area of the width of the reinforcing rib is located within the area of the width of the protruding piece. By doing so, the reaction force of the caulking force acting on the folded portion via the protruding piece partially disappears at the shearing edge of the reinforcing rib, and as a result, the reaction force becomes considerably small.

According to the present invention, there is provided a first plate member having an opening,
It is widely applied to a joint structure between a second plate member and a second plate member which are joined to each other in a positional relationship substantially orthogonal to the plate member. As a typical application, this joint structure is applied to a joint structure of an inner box of a cooking appliance such as a microwave oven. In this case, the first plate member is the front plate of the inner box of the cooking appliance, and the second plate member is the top plate of the inner box of the cooking appliance.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A joint structure of a front plate and a top plate of an inner box of a cooking appliance, which is a typical application example of the present invention, will be described with reference to FIGS. Although FIG. 1 illustrates the final joint structure, the steps until the final structure is obtained will be described in order.

First, as shown in FIG. 4, a front plate 20 having an opening 26 is prepared. In the following figures, the part surrounded by B in FIG. 4 is shown.

As shown in FIG. 5, by shearing,
A plurality of protruding pieces 23 are formed on the front plate 20.

Next, as shown in FIG. 6, triangular pyramidal reinforcing ribs 24 are formed so as to contact the base ends of the respective protruding pieces 23. 7 is a sectional view taken along the line CC of FIG. 6, and FIG. 8 is a sectional view taken along the line DD of FIG.

The bottom surface of the triangular-pyramidal reinforcing rib 24 substantially coincides with the position of the base end portion of the protruding piece 23 and is sheared and separated from the front plate 20. The width dimension of the shearing edge 25 is smaller than the width dimension of the reinforcing rib 23, and the width region of the reinforcing rib 24 is located within the width region of the protruding piece 23.

Next, as shown in FIGS. 9 and 10, the projecting piece 23 is bent to have a predetermined inclination angle.

Next, as shown in FIGS. 11 and 12,
The front plate 20 is folded back 180 ° from the front surface side to the back surface side with the opening edge 21 as a boundary. In FIG. 11, the folded portion 22 appears on the paper surface side. That is, in this figure, the back side of the front plate 20 corresponds to the front side of the paper.

FIG. 2 is a perspective view corresponding to FIGS. 11 and 12. Next, as shown in FIG. 13, the tip portion 31 of the top plate 30 and the protruding piece 23 of the front plate 20 are fitted together. The tip portion 31 of the top plate 30 is bent so that the protruding piece 23 of the front plate 20 can be sandwiched.

In the state shown in FIG. 13, by performing a caulking process in which a caulking force is applied in a direction indicated by an arrow A,
Finally, the junction structure shown in FIGS. 14 and 1 is obtained.
At the time of caulking, a reaction force of the caulking force acts on the folded-back portion 22 of the front plate 20, but the presence of the reinforcing ribs 24 prevents the folded-back portion 22 from bending.

FIG. 3 shows the front plate 20 after being crimped. In this figure, the top plate is not shown. Of the front plate 20, the caulking process is the protruding piece 23.
Only. Therefore, the reaction force of the caulking force is
3 and the folded portion 22. A shearing edge 25 of the reinforcing rib 24 is present in the connection region between the protruding piece 23 and the folded portion 22. The reaction force of the caulking force cannot pass through the shear edge 25. After all, the reaction force of the caulking force passes through the small connecting portion between the protruding piece 23 and the folded portion 22. Therefore, the reaction force acting on the folded-back portion 22 becomes small.

Due to the reaction force reduced as described above and the presence of the reinforcing ribs 24, it is possible to effectively prevent the bent portion 22 from being bent at the time of caulking.

The reinforcing rib 24 has a triangular pyramid shape because
This is because the reaction force is greatly reduced while maintaining the strength of the folded portion 22. That is, by providing the shear edge 25 on the bottom surface of the triangular pyramid reinforcing rib 24 occupying a large width dimension, the reaction force acting on the folded portion 22 is greatly reduced.

The joining structure shown in FIGS. 1 to 4 is only one embodiment of the present invention. Therefore, various modifications and variations are possible. For example, in the illustrated embodiment, the tip of the folded-back portion has the protruding piece protruding in the direction away from the opening edge, but the formation of such protruding piece can be omitted.

Further, in the illustrated embodiment, the end portion on the tip end side of the reinforcing rib is shear-separated from the folded-back portion, but the reinforcing rib is simply protruded toward the back surface side without being shear-separated. Is also possible.

Further, although the joint structure of the inner box of the cooking appliance has been described as an example, the same joint structure can be applied to other uses.

[Brief description of drawings]

FIG. 1 is a perspective view showing a joint structure of a front plate and a top plate.

FIG. 2 is a perspective view showing a front plate before being caulked.

FIG. 3 is a perspective view showing the front plate after being caulked.

FIG. 4 is a plan view showing a front plate having an opening.

FIG. 5 is a plan view showing the front plate after forming the protruding piece.

FIG. 6 is a plan view showing a front plate after forming reinforcing ribs.

7 is a cross-sectional view taken along the line CC of FIG.

8 is a cross-sectional view taken along the line DD of FIG.

FIG. 9 is a plan view showing a state after the protruding piece is bent at a predetermined angle.

10 is a cross-sectional view taken along the line EE of FIG.

FIG. 11 is a plan view showing a state after the folded-back portion is formed by folding the front plate 180 ° along the opening edge.

12 is a cross-sectional view taken along the line FF of FIG.

FIG. 13 is a cross-sectional view showing a front plate and a top plate before caulking.

FIG. 14 is a sectional view showing a front plate and a top plate after caulking.

FIG. 15 is a perspective view showing a microwave oven.

FIG. 16 is a perspective view showing an inner box of the cooking appliance.

FIG. 17 is a cross-sectional view showing a conventional joint structure between a front plate and a top plate.

FIG. 18 is a cross-sectional view showing a front plate and a top plate joined by caulking.

FIG. 19 is a sectional view showing a front plate and a top plate before caulking.

FIG. 20 is a cross-sectional view showing a front plate and a top plate during caulking.

[Explanation of symbols]

 20 front plate 21 opening edge 22 folded part 23 protruding piece 24 reinforcing rib 25 shear edge 30 top plate 31 tip part

Claims (5)

[Claims] 1. A joining structure between plate members, wherein a first plate member having an opening and a second plate member arranged in a substantially orthogonal positional relationship are joined to each other, wherein the first plate member has an opening edge. Has a folded-back portion that is folded back 180 ° from the front surface side to the back-side surface, and the tip portion of the folded portion and the tip portion of the second plate member,
The joining structure between the plate members is joined by caulking, and the folded-back portion is provided with a reinforcing rib protruding toward the back surface side between the tip end portion to be caulked and the opening edge. 2. The reinforcing rib extends from the opening edge toward the tip portion, and the end portion of the reinforcing rib on the tip end side is sheared and separated from the folded portion. The joining structure between the plate materials described in. 3. A tip portion of the folded-back portion has a protruding piece protruding in a direction away from the opening edge, and the protruding piece is joined to the second plate member by caulking, and the reinforcing member The joint structure between plate materials according to claim 1, wherein the rib extends from the opening edge toward the protruding piece. 4. An end edge of the reinforcing rib located on the protruding piece side is sheared and separated from the folded portion, and a width dimension of the reinforcing rib when viewed in a direction parallel to the opening edge is the The joining structure between plate materials according to claim 3, wherein the width dimension of the protruding piece is smaller than the width dimension of the protruding piece, and the area of the width of the reinforcing rib is located within the area of the width of the protruding piece. 5. The first plate member is a front plate of an inner box of the cooking appliance, and the second plate member is a top plate of the inner box of the cooking appliance. The joining structure between the plate materials according to the item.