JPH0612176B2 - Inner box of cooking equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement in the structure of an inner box of a cooking appliance obtained by joining a plurality of metal plates by plastic working using a plurality of metal plates.

[Prior Art] A microwave oven usually has a double-structured casing including an outer box and an inner box. An example of this kind of inner box is
82012. The inner box of the cooking appliance disclosed in this prior art will be described with reference to FIGS. 2 and 3.

In the inner box 1 of the cooking appliance shown in FIG. 2, the front plate 3, the tubular body 4 and the rear plate 5 having the openings 2 are all made of a body plate and are joined to each other by curling.
Further, as shown in a perspective view in FIG. 3, the tubular body portion 4 itself is also configured by joining a body plate 7 bent in a U shape and a top plate 8 by curling.

[Problems to be Solved by the Invention] In the inner box 1 of the conventional cooking apparatus described with reference to FIGS. 2 and 3, the respective constituent members are joined by curling. Therefore, it is possible to perform the joining while using the coated steel sheet, and it is possible to omit the complicated painting work.

However, when joining by curling, particularly when joining the front plate 3, the rear plate 5, the body plate 7, and the top plate 8 simultaneously by an automatic machine, the parts that contribute to the joining of the respective constituent members are It must be processed into a complicated shape in advance. Therefore, it is possible to efficiently perform the step of joining the constituent members where the curling margin has already been formed, but a considerable step is required for the formation of the curling margin which is the preceding step, and sufficient attention should be paid to the quality of processing. I had to pay.

Conventionally, in addition to joining by curling, those using rivets, those using spot welding, and those using bolts and nuts have also been implemented, but other parts such as rivets and bolts and nuts And also requires complicated painting work. Therefore, the productivity was nothing more than that of the inner box of the cooking appliance obtained by the curling process.

Therefore, an object of the present invention is to provide an inner box of a cooking appliance having a structure capable of being efficiently produced without requiring a complicated pre-process.

[Means for Solving the Problems] The inner box of the cooking appliance of the present invention also utilizes plastic working of a metal plate, as in the case of curling. The inner box of the cooking appliance of the present invention includes a front plate, a tubular body portion, and a rear plate.

At the rear end of the tubular body, a flange piece is formed on the peripheral edge of the opening. A plurality of cut-and-raised pieces that are engaged with the flange pieces of the tubular body portion are formed on the rear plate. This cut-and-raised piece is formed by being cut and raised on the rear plate so as to have a through hole.

A part of the flange piece is press-molded together with the cut-and-raised piece so as to be press-fitted into the through-hole while being sandwiched between the through-hole and the cut-and-raised piece.

The press-fitted part of the flange piece is located on the same plane as the rear plate,
The cut-and-raised piece lies approximately flush with the rest of the flange piece. In this way, the entire peripheral edge of the press-fitting portion of the flange piece of the tubular body portion is locked by the peripheral wall of the through hole, and the tubular body portion and the rear plate are joined.

[Operation] In the present invention, the flange piece is simply formed at the rear end of the tubular body portion to be joined. Further, only a plurality of cut-and-raised pieces are formed on the rear plate side.
Therefore, the cylindrical body portion and the rear plate can be immediately joined without requiring a complicated curling margin forming step.

In addition, the press-fitting portion of the flange piece is located on substantially the same plane as the rear plate, and the cut-and-raised piece is located on substantially the same plane as the rest of the flange piece. Since the entire peripheral edge is locked by the peripheral wall of the through hole, no positional deviation occurs between the tubular body and the rear plate. In this way, a strong joint structure is obtained.

[Description of Embodiments] FIG. 1 is a perspective view showing an inner box of a cooking appliance according to an embodiment of the present invention. The inner box 11 has a front plate 13 having an opening 12.
And a tubular body portion 14 and a rear plate 15. Tubular body 1
4 is a body plate 1 made of a metal plate bent in a U-shape, as in the case of the inner box 1 of the conventional cooking appliance shown in FIG.
7 and the top plate 18 are joined together.

By the way, the inner box 11 of this embodiment is characterized in that the joint structure between the body plate 17 and the top plate 18, the joint structure between the top plate 18 and the rear plate 15, and the body plate 17 and the rear plate 15. It is in the joint structure between. The joining between the front plate 13 and the tubular body 1 is performed by the known curling process described in Japanese Utility Model Laid-Open No. 57-182012.

Next, the manufacturing process of the inner box 11 will be described. As shown in FIG. 4, a body plate 17 bent in a U shape is prepared. The body plate 17 is joined to the top plate 18 to form the cylindrical body portion 14.
(See FIG. 1). Flanges 21 ... 23 are formed on the rear edge of the body plate 17. Similarly,
A flange piece 24 is also formed on the rear edge of the top plate 18. Further, the second flange pieces 25 and 26 are also formed on the upper end of the body plate 17 that contributes to the joining with the top plate 18.

On the other hand, in the rear plate 15 joined to the body plate 17 and the top plate 18, a plurality of through holes 31 are formed along the rear edge of the opening of the tubular body portion 14. As shown in the perspective view of FIG. 5, each through hole 31 is cut forward from the rear plate 15 to be smaller than the through hole 31 (that is, when cutting and raising, the periphery of the cut and raised piece 32 is slightly cut off). It is the result of forming the raised piece 32. Therefore, in FIG. 4, a plurality of through holes 31
In part, all the cut-and-raised pieces 32 extend forward. Of course, each cut-and-raised piece 32 is formed so as to extend forward from the peripheral wall on the outer peripheral side of the through hole 31 in order to perform the joining described later. Therefore,
It can be seen that the cut-and-raised piece 32 shown in FIG. 5 is formed on the upper side of the rear plate 15 in FIG. The front portion of the cut-and-raised piece 32 is bent so as to return to the through hole 31 side. This is to facilitate the later-described molding.

Returning to FIG. 4, the top plate 18 is also provided with a plurality of through holes 41 by forming cut-and-raised pieces 42. Here again, the cut-and-raised pieces 42 are cut and raised so as to be located on the outer peripheral side of the top plate 18. Although not apparent in FIG. 4, the tip end portion of the cut-and-raised piece 42 is also slightly returned to the side of the through hole 41, like the cut-and-raised piece 32.

In the inner box of this embodiment, the cut-and-raised pieces 31, 4 described above are used.
1 and the flange pieces 21 ... 23 and 25, 26 are used to join the top plate 18 to the body plate 17, the top plate 18 to the back plate 15, and the body plate 17 to the back plate 15. Be done. Since all of these joint structures themselves are identical,
In the following description, joining of the top plate 18 and the rear plate 15 will be described as a representative.

With reference to FIG. 6, the flange piece 24 of the top plate 18 is moved in the direction of the arrow A shown in the drawing to overlap the through hole 31 of the rear plate 15. At this time, the flange piece 24 is attached to the through hole 3
Cut-and-raised piece 32 to move so as to face 1.
The front end of the front portion 32a and the front end of the flange piece 24 are prepositioned to have a distance X. In addition,
As is apparent from FIG. 6, the front portion 32a of the cut-and-raised piece 32 extends slightly returned to the through hole 31 side as described above (the front portion 32a has a length corresponding to the thickness of the flange piece 24). Is bent at the tip of the base.). Therefore, with the flange piece 24 superposed on the rear plate 15,
If a die is brought into contact and press-formed, the joining structure shown in FIGS. 7 to 9 can be obtained. That is, as shown in FIG. 8, the front surface 32 b of the cut-and-raised piece 32 and the front surface 2 of the flange piece 24.
4a and 4a are formed so as to be substantially in the same plane.
Therefore, the end portion 24b of the flange piece 24 is press-fitted into the through hole 31.

In addition, preferably, as shown by an imaginary line Z in FIG. 6, if the tip end on the flange piece 24 side is also bent, both portions to be joined can be more easily overlapped. Therefore,
Assembly by an automatic machine becomes easier.

In the joint structure shown in FIGS. 7 to 9, the flange piece 2 is used.
The base end 27 of the press-fitted portion 24b of No. 4 is locked to the lower end 31a of the peripheral wall of the through hole 31. Therefore, in the state shown in FIG. 8, even if an external force is applied in a direction in which the top plate 18 and the rear plate 15 are moved away from each other, the engagement between the base end 27 of the press-fitted portion 24b and the lower end 31a of the through hole peripheral wall is reduced. It can be seen that the top plate 18 and the rear plate 15 are firmly joined to each other by the stop, so that the structure is extremely unlikely to come off.

Next, looking at the joint structure from different angles, as shown in FIG. 9, both widthwise ends of the press-fitted portion 24b of the flange piece 24 are part of the peripheral wall of the through hole 31, that is, the side wall 31.
It is locked by b and 31c. Therefore, it can be seen that the top plate 18 and the rear plate 15 do not shift even when an external force is applied in the left-right direction of the inner box, and thus a strong joint is realized.

In addition, preferably, if the distance R in FIG. 9 is shortened, the lateral displacement of the top plate 18 and the rear plate 15 in FIG. 9 can be more reliably prevented. Therefore, it is preferable that 1/2 of the difference between the width of the cut-and-raised piece 32 and the width of the through hole 31 should be narrower than the thickness of the top plate 18.

The top plate 18 and the rear plate 15 of the inner box 11 shown in FIG. 1 are joined as described above. Joining between the top plate 18 and the body plate 17 and the body plate 17 and the rear plate 1
The same is applied to the connection with No. 5.

By the way, also in the inner box 11 of this embodiment, coated steel plates are used as the respective constituent members in order to facilitate the joining work and particularly to omit the painting work. On the other hand, in the inner box 11 of the cooking appliance, each component must be electrically connected. Therefore, when using coated steel sheets,
Ensuring continuity becomes a problem. However, in the inner box 11 of this embodiment, as shown in FIG. 9, the flange piece 24 is the edge of the cut-and-raised piece 32 (because it is exposed by the cut-and-raised portion, the coating film is naturally formed on the surface. The part that does not have) is damaged. Therefore, it can be seen that the conduction between the flange piece 24 and the cut-and-raised piece 32 is secured. This also applies to other joints.

As described above, in the inner box 11 of this embodiment, as shown in FIG. 4, the top plate 18, the body plate 17 and the rear plate 15 need not be subjected to complicated pre-processing, that is, the body plate. It can be seen that the flange pieces 21 ... 26 are formed on the other side and the cut-and-raised pieces 31, 41 are formed on the other side of the top plate 18 and the rear plate 15 to easily join them by press molding.

In the inner box 11 of the microwave oven, a waveguide is often attached to the outside of the body plate or the top plate, but this type of waveguide can also be joined using the above-described joining structure. This example will be described with reference to FIGS. 10 and 11. 10 and 11, the top plate 18 (top plate 1
An opening 35 is formed in only the central portion of 8), and a box-shaped metal member 36 forming a waveguide is joined to the top plate 18 so as to cover the opening 35. Here again, a cut-and-raised piece 52 cut and raised to have a through hole 51 is formed on the top plate 18 side, and flange pieces 53 ... 55 are formed on the peripheral edge of the metal member 36. 55 and the cut-and-raised pieces 52 are joined in the same manner as the joining between the top plate 18 and the rear plate 15 described above, and the flange pieces 53 ... 55 are attached as shown in FIG. ing. Thus, the inner box 11 shown in FIG.
It will be appreciated that not only the body, but also the metal members mounted around it can be easily joined using the characteristic joining structure of this embodiment described above.

In the above-mentioned embodiment, the tubular body portion 14 is composed of the body plate 17 and the top plate 18, but the tubular body portion 14 may be composed of a metal member formed in a tubular shape in advance. Needless to say.

[Advantages of the Invention] In the present invention, a flange piece is formed at the rear end of the tubular body portion, and a plurality of cut-and-raised pieces that are locked to the flange piece are formed on the rear plate side so as to have through holes. It is awakened and formed. A part of the flange piece is press-molded together with the cut-and-raised piece so as to be press-fitted into the through-hole while being sandwiched between the through-hole and the cut-and-raised piece. By this press forming, the press-fitted portion of the flange piece is located substantially flush with the rear plate, and the cut-and-raised piece is located substantially flush with the rest of the flange piece, which allows the flange piece of the tubular body to The entire peripheral edge of the press-fitted portion is locked by the peripheral wall of the through hole. As a result, displacement between the tubular body and the rear plate is prevented, and a strong joint structure is obtained between the two. In this way, it is possible to efficiently form the inner box without performing complicated pre-processing on the rear end of the tubular body and the rear plate.

Furthermore, since the press-fitted portion of the flange piece is located on substantially the same plane as the rear plate, and the cut-and-raised piece is located on substantially the same plane as the rest of the flange piece, no particular protruding portion appears, and a finger is placed on the protruding portion. It does not pose a risk of being caught and injured, and does not impair the appearance.

[Brief description of drawings]

FIG. 1 is a perspective view showing an inner box of a cooking appliance according to an embodiment of the present invention. FIG. 2 is a perspective view showing an example of an inner box of a conventional cooking appliance. FIG. 3 is a perspective view for explaining a process of assembling the inner box of the conventional cooking device shown in FIG. FIG. 4 is a perspective view for explaining a process of assembling the embodiment shown in FIG. FIG. 5 is an enlarged perspective view for explaining the cut-and-raised piece in the embodiment of FIG. FIG. 6 is an enlarged cross-sectional view for explaining the joining structure in the embodiment of FIG. FIG. 7 shows a front view of the joint structure in the embodiment of FIG. 1, particularly a front view of the joint structure between the top plate and the rear plate. Figure 8 shows VIII in Figure 7.
-VIII is a sectional view taken along the line, and FIG. 9 is a sectional view taken along the line IX-IX in FIG. 10 and 11 are perspective views for explaining the process of joining the waveguide to the top plate. In the figure, 11 is an inner box of the cooking appliance, 12 is an opening, and 13
Is a front plate, 14 is a cylindrical body, 15 is a rear plate, 17 is a body plate, 1
8 is a top plate, 21 ... 26 are flange pieces, 31 and 41 are through holes, and 32 and 42 are cut and raised pieces.

Claims (1)

[Claims] 1. An inner box of a cooking appliance comprising a front plate, a tubular body, and a rear plate, the inner box of the cooking appliance being obtained by plastic working of a metal plate, wherein the rear end of the tubular body has an opening peripheral edge. A flange piece is formed, and a plurality of cut-and-raised pieces that are locked to the flange piece of the tubular body portion are formed on the rear plate, and the cut-and-raised pieces are formed on the rear plate so as to have a through hole. It is formed by cutting and raising, and a part of the flange piece is press-molded together with the cut-and-raised piece so as to be press-fitted into the through-hole while being sandwiched between the through-hole and the cut-and-raised piece. The press-fitting portion of the flange piece is located substantially flush with the rear plate, and the cut-and-raised piece is located substantially flush with the rest of the flange piece, whereby the flange piece of the tubular body is The entire peripheral edge of the press-fitted portion of is locked by the peripheral wall of the through hole. An inner box for a cooking appliance, in which a tubular body and a rear plate are joined together.