JPS59119118A - Inner chamber of cooker - Google Patents

Abstract

PURPOSE:To obtain an inner chamber of an inexpensive cooker excellent in the joint strength by joining a front plate with the body section by curling processing. CONSTITUTION:A first curling margin 25 is formed at the open end rim 5b of an opening 5a of a front plate 5. As clearly shown by the drawing indicating the part at VI on an enlarged scale, the first curling margin 25 comprises a first bent section 25a bent almost vertical to the body section from the main surface of the front plate 5 and a second bent section 25b extending in the direction of expanding the opening from the tip of the first bent section 25a. On the other hand, a second curling margins 13a, 13B and 13C are formed on a body plate 10 and a top board 9 composing the body section 6. The joining of the front plate 5 with the body section 6 is performed by putting the first curling margin 25 of the front plate 5 together with the second curling margins 13A, 13B and 13C formed on the body section 6 by curling processing.

Description

DETAILED DESCRIPTION OF THE INVENTION L1 to 1 This invention relates to improvements in the joint structure of an inner box used in cooking appliances such as microwave ovens, and particularly relates to a front plate in which an opening is formed and a frontage edge of the front plate. This invention relates to an improvement in the joint structure with a cylindrical body connected to the cylindrical body.

FIG. 1 and FIG. 2 are schematic perspective views showing an inner box of a microwave oven as an inner box of a cooking appliance that gave rise to the present invention. The microwave oven 1 consists of a main body 2 and a door 3. The main body 2 includes an inner box 4.

A heating cooker such as a microwave oven is provided with an inner box 4 in order to effectively utilize heat and prevent leakage of radio waves, and therefore the main body 2 has a double structure.

As is clear from FIG. 2, the inner box 4 includes a front plate 5 having an opening 5a, a cylindrical body 6 joined to the opening edge 5b of the front plate, and a rear end of the body 6. and a rear plate 7. By the way, the front plate 5 and the body 6 have conventionally been joined by spot welding. The front plate 5 is thicker than the opening area of the body 6 (therefore, the usual curling process that is advantageously used for joining metal plates cannot be performed. However, since spot welding was used,
Problems include that the joining process itself is extremely cumbersome and that a repainting process is required after joining.

On the other hand, in the inner ff14 as shown in FIG.

When joining the front plate 5 and the body part 6, it is also possible to use a conventionally known caulking process. however,
Caulking is simply a method of fixing metal plates, and the joint strength is extremely weak, so this type of inner box 4
It cannot be said that this is an effective joining method. .

Further, as shown in a partial cross-sectional view in FIG.
0 and the engagement protrusion 40 are provided at a plurality of locations to prevent displacement in the Y direction and the −Y direction;
can also be considered. However, the engaging protrusion 40 and the opening 41
It is not practical because it requires complicated work to align the two.

Therefore, the main object of the present invention is to solve the above-mentioned problems and provide an inexpensive inner box for a cooking bowl with excellent joint strength.

The present invention is an inner box for a cooking appliance in which a front plate and a body are joined by a curling process.

Preferably, the front plate and the body are joined by a curling process performed between a first curling margin formed on the front plate and a second curling margin formed on the chest,
This first curling margin is formed by a first bent part bent almost perpendicularly from the main surface of the front plate toward the body side, and a second bent part extending from the tip of the first bent part in the direction of widening the opening. On the other hand, the second curling margin includes a third bent portion extending outward from the main surface of the body substantially perpendicularly, a fourth bent portion extending from the tip of the W43 bent portion toward the front plate, and a fourth bent portion extending outward from the main surface of the body portion in a direction substantially perpendicular to the outside. It consists of a fifth bent part bent in a direction that narrows the trunk opening from the tip of the bent part.

Other features of the invention will become clearer from the following description of the embodiments.

Friend ao'11 FIG. 3 is a perspective view showing an inner box of a cooking appliance according to an embodiment of the present invention. The inner box 4 is formed by curling at each joint. That is, the front plate 5 and the body plate 1
0. The front plate 5 and the top plate 9, the body plate 10 and the rear plate 7, and the top plate 9 and the rear plate 7 are all joined by curling. Among these, in particular, the structure of each joint between the cylindrical body 6, which is composed of the body plate 10 and the top plate 9, and the front plate 7 is characterized by a structure that is a feature of the present invention, as will be described later. It has been adopted.

FIG. 4 is a perspective view showing the first step of forming each joint shown in FIG. 3. The body plate 10 is made of a metal material such as stainless steel, and has three holes on one of its longitudinal sides.
Curling room 11A.

11B, 11C and flange portions 912A, 12B, and three curling margins 13 are formed on the other longitudinal side.
A, 138.13G and flange parts 14A, 14B
(not shown), one curling allowance 15A, 15B is formed on the other two sides, and then the entire board is folded and bent so that the longitudinal sides become U-shaped. It will be done. Curling space 16.17.18.1 is placed on the top plate 9.
9 are respectively formed on their outer peripheral edges. On the rear plate 7,
Curling margins 2OA, 20B, 20C, and 20D are formed at the outer peripheral edges, respectively.

A top plate 9 and a body plate 10 each having curling marks formed thereon.
And the rear plate 7 is joined to the following J:゛). , the top plate 9 is assembled to the main body plate 10 in the direction of arrow P in FIG. Next, curl on the top plate, ring margin 17, copper plate curling margin 15B1, and curling margin 19 on the top plate.
and the curling margin 15A of the body plate are joined by curling process. After the top plate 9 is joined to the copper plate 10 by curling, the rear plate 7 is assembled from the direction of the arrow Q in FIG. Next, the body plate 10
Curling margin 11△ and curling margin 2 of 1 and board 7
0B, curling margin 11B of IR board 10, curling margin 20C of rear plate 7,, 1ii curling margin 11C of IO, curling margin 20D of rear plate 8, and top plate 9
Curling allowance of 16 and curling allowance of rear plate 7 of 2OA
are joined by curling process. As described above, by performing the curling process at six locations, the top plate 9, the body plate 10J3, and the rear plate 7 are each firmly joined.

These curling processes are done in the patent application Elf by the same applicant.
(It can be carried out advantageously by the apparatus and method disclosed in JP-A-55-542-30, JP-A-55-54231 and JP-A-55-542'21.
The curling processes at these locations show the same joint structure, and differ only in positional relationship. Therefore, only the joint between the top plate 9 and the rear plate 7 will be representatively explained.

The curling margin 16 of the top plate 9 is the rear edge 9b of the top plate 9.
The first overhanging portion 16a is bent at a right angle to the top plate 9 and extended, and the first overhang portion 16a is bent at a right angle at the tip of the first overhang portion 16a and parallel to the main surface of the top plate 9. It is composed of a second overhanging portion 16b that extends to the left, and a third overhanging portion 16c that is bent diagonally downward at the tip of the second overhanging portion. The curling margin 2OA of the rear plate 20, which forms a curling portion together with the curling margin 16 of the top plate 9, is composed of an overhanging portion extending rearward at right angles to the main surface of the rear plate 7 above the rear plate 7. be done. The rear plate 7 is the body plate 10 and the top plate 9
When the curling margin 16 is brought into contact with the curling margin 16, the curling margin 20A is positioned so that the second protruding portion 16b of the curling margin 16 and the curling margin 20A are overlapped. First, a support member is brought into contact with one front surface of the first overhanging portion 16a of the curling margin 16, that is, the opposite side to the second overhanging portion 16b, and the curling mold is pressed from behind, that is, from the rear plate 7 side. Perform the curling process.

The state of this curling process is shown in FIG.

Next, the joining structure between the front plate 5 and the body plate 10 and between the front plate 5 and the top plate 9, which are features of the present invention, will be explained. FIG. 5 is a rear perspective view of the front plate 5. FIG. A first curling margin 25 is formed at the opening edge 5b of the opening 5a of the front plate 5. As is clear from FIG. 6, which is an enlarged view of the portion indicated by Vl in FIG. Bending part 2
5a, and a second bent portion 251+ extending from the tip of the first bent portion 25a in a manner that widens the opening. On the other hand, the trunk 6
Second curling margins 13A, 13B, 13G, and 18 are formed on the body plate 10 and the top plate 9 that constitute the main body plate 10 and the top plate 9. The front plate 5 and the body 6 are joined by the first curling margin 25 of the front plate 5 and the second curling margins 13A and 13B formed on the body 6.

13C and 18 are joined by car link processing.The joining structure between the front plate 5, the top plate 9, the front plate 5, and the body plate 10 is the same, so the following explanation will be given. Now, the joining structure of the front plate 5 and the top plate 9 will be explained as a representative example.

As shown in FIG. 4, the second curl link margin 18 of the top plate 9 includes a third bent portion 18a extending outward from the main surface of the first large plate 9 substantially perpendicularly, and a third bent portion 18a extending from the tip of the third bent portion to the front. It consists of a fourth bent part 18b extending in the direction of the plate, and a fifth bent part 18c bent from the tip of the fourth bent part 18b in a direction that narrows the body opening.

FIG. 7 is a partially cutaway sectional view for explaining the process of joining the first curling margin 25 and the second curling margin 18 of the top plate 9, and FIG. 8 is a partially cutaway sectional view showing the joined state. FIG. When the front plate 5 approaches the top plate 9, as shown in FIG.
The curling margin 18 is approached. In this state, the first curling space 25 and/or the second curling space 1
A curling process as shown in FIG. 8 is performed by pressing a curling die from the periphery of the pieces 8 so as to move them in a direction in which they come into contact with each other.

As is clear from FIG. 8, it can be seen that the joint between the front plate 5 and the top plate 9 by the curling process is firmly joined. Further, a curved portion 26 (see FIG. 8) formed between the second bent portion 25a of the curling margin 25 of the front plate 5 and the main surface of the front plate 5 has a relatively large radius of curvature. Between the first bent portion 25a and the main surface of the front plate 5, a fifth bent portion 18C1 of the top plate 9, a second bent portion 25b1 of the front plate 5, and a fourth bent portion 18b of the top plate 9 are provided. This is because it becomes an intervening state. Therefore, the front plate 5 made of inexpensive painted steel plate
Even if the paint is used, there is no risk that the paint will peel off on the curved portion 26.

FIG. 9 is a partially cutaway sectional view showing the joint structure of the front plate 5 at the corner portion of the front edge 5b of the front plate 5 with the body plate 10. As is clear from FIG. 9, the seven flange portions 14A, 14B of the copper plate 10 are pressed against the first bent portion 25a of the first curling margin 25 of the front plate 5 at the corner portion.

Therefore, although no curling process is performed, the first curling margin 25 and the flange portions 14A, 14B are both strongly pressed against each other by the springback movement. Therefore, the joint between the front plate 5 and the body 1fii10 has sufficient adhesion even at the corner portion of the opening edge 5b of the opening 5a.

o i As described above, according to the present invention, the front plate and the body are joined by curling, so there is no need for complicated work such as positioning, and the joining strength is excellent and the cost is low. You can get the inner box of the equipment. In addition, because it uses a curling process and does not form a curved surface with a small radius in a place that is easily visible from the outside, it is possible to use extremely cheap painted AS*i as a curved plate, which makes it possible to The cost of the inner box can be reduced very effectively. Moreover, the troublesome qlA step required when joining by spot welding can also be omitted.

[Brief explanation of drawings]

FIGS. 1 and 2 are perspective views of the electric circuit of the inner box of the conventional 'A' eel equipment that made this invention possible. FIG. 3 is a schematic perspective view showing an embodiment of the present invention. FIG. 4 is a perspective view showing the first incision forming each joint shown in FIG. 3. FIG. Figure 5 is a diagonal diagram C of the curved board housing. FIG. 6 is a partially cutaway perspective view showing an enlarged portion indicated by VI in FIG. 5. FIG. The seventh panel is a partially cutaway sectional view showing a process of joining the first curling margin and the second curling margin. FIG. 8 is a partially cutaway cross-sectional view showing the joining shape 1 of the first curling groove and the 12 curling groove. FIG. 9 is a partially cutaway sectional view showing the joint between the front plate and the chest plate by J'3t at the corner portion of the opening edge of the front plate. There is 2" in the picture. In the figure, 4 is the inner box, 5 is the front plate, 5a is the opening of the front plate,
5b is the front plate front edge, 6 is the body, 7 is the rear plate, 13A, 1
．． 3B, 130.18 is the second curling l, ro, 1F3
81.4 3rd bending part, 1811 4th bending part, +80 5th bending part, 25 1st curling part, 25a 1st bending part
The bent part and 25b indicate the second bent part (two idiots).

Claims (2)

[Claims] (1) In an inner box of a cooking appliance comprising a front plate having an opening, a 1ζζ cylindrical part joined to the opening edge of the front plate, and a rear plate joined to the rear edge of the body, the front An inner box for a cooking appliance, characterized in that a board and a body are joined by a curling process. (2) The front plate and the body are joined by a first curling margin formed on the front plate and a second curling margin formed on the body, and the first curling margin is connected to the front plate. It consists of a first bent part bent almost perpendicularly from the main surface of the board toward the trunk side, and a first bent part extending from the tip of the second bent part in a direction to widen the frontage, and the second curling margin is 1. A third bent part extending outward from the main surface of the body substantially perpendicularly, a fourth bent part extending from the tip of the third bent part in the direction of the front plate, and a body opening from the tip of the fourth bent part. The inner box of the cooking appliance according to claim 1, comprising a fifth bent portion bent in a direction to narrow the inner box.