The present invention relates to a structure of a cabinet of a high-frequency heating device such as a microwave oven.

As shown in Fig. 8, the high-frequency heating device such as the microwave oven usually includes a heating chamber, a front plate of a peripheral edge of an opening part of the heating chamber, a rear plate in a rear part of the heating chamber, a cover which covers an upper surface and right and left side surfaces of the heating chamber and a bottom plate. The front plate and the rear plate are allowed to stand upright on the bottom plate. Further, the cover is fixed to the front plate and the rear plate. When the cover is fixed to the front plate and the rear plate, a pawl of the cover formed by folding back a front edge of one metal plate is attached by sandwiching a flange of the front plate formed by bending inside an outer peripheral edge of the front plate, so that the cover is engaged with the front plate. A flange formed by bending a rear edge of the cover inside is screwed to the rear plate.

As an attaching method of a cover, there is another method in which, for instance, a screwing operation is saved when the cover is fixed to a rear plate to fit a pawl of the cover to an engaging piece provided in the rear plate, so that the cover is fixed (for instance, see Patent Document 1).

Further, in the attaching method of the cover, when outer peripheral edges of a front plate and a rear plate have curved forms, pawls of a front edge and a rear edge of the cover and the form of the cover are changed so as to meet a structure of a cabinet having the curved surfaces (see Patent Document 2).

• Patent Document 1: JP-U-S56-136511
• Patent Document 2: JP-A-2002-130688

However, in the above-described attaching method of the cover of the usual high-frequency heating device, the pawl of the cover provided in the front edge of the cover is engaged with the flange of the front plate and the rear plate is screwed to fix the cover. Accordingly, the high-frequency heating device to which the cover is attached by the above-described attaching method has a structure that a front surface of the cover has flexibility in a vertical direction due to a clearance provided between all the edge of the cover and the flange of the front plate. Accordingly, a problem arises that when the high-frequency heating device is carried, the front surface of the cover moves in the vertical direction to change the clearance between the front plate and the cover.

Further, since the flange of the front plate has only strength of the thickness of the plate, the flange is liable to be deformed. A problem arises that when the cover is attached to the front plate under a state that the flange of the front plate is deformed, the cover is obliquely attached thereto. Further, a problem arises that when a rib is provided in a bottom plate to suppress a vertical movement by a flange formed by bending an outer peripheral edge of a cover inside, since the flange provided in the cover has only strength of the thickness of the plate, the strength is low to deform the cover when a load is applied thereto.

An object of the present invention is to provide a high-frequency heating device which can suppress a vertical movement of a front surface of a cover attached to a front plate attached to a peripheral edge of an opening part of a heating chamber.

The present invention provides a high-frequency heating device including: a heating chamber in which an object to be heated is placed; a front plate arranged in a peripheral edge of an opening part of the heating chamber; and a cover which covers the heating chamber and is attached to the front plate, wherein the front plate includes engaging bodies which suppress the vertical movement of the cover, and wherein pawls of the cover are partly cut out so as to meet the engaging bodies of the front plate so that the pawls of the cover are fixed in a vertical direction by the engaging bodies.

Thus, when a user carries the high-frequency heating device, even if the user applies a force in a vertical direction thereto, the pawls of the cover are fixed by the engaging bodies provided in the front plate, so that the vertical movement of the cover can be prevented and the change of a clearance between the front plate and the cover can be prevented.

Further, when the pawls provided in the cover sandwich flanges of the front plate under a state that the flange of the front plate is deformed, the pawls of the cover are fixed by the engaging bodies provided in the front plate. Thus, the flange of the front plate is remedied so that the cover can be prevented from being obliquely attached to the front plate.

Further, when the pawls provided in the cover insufficiently sandwich the flanges of the front plate, the pawls of the cover are fixed by the engaging bodies provided in the front plate. Thus, the flanges of the front plate are remedied so that the cover may be prevented from being obliquely attached to the front plate.

In the above-described high-frequency heating device, an end face of the engaging body is formed to be round. When the pawls provided in the cover sandwich the flanges of the front plate, since the end faces of the engaging bodies provided in the front plate are formed to be round, a resistance during the sandwiching is reduced. As a result, since an attaching operation of the cover is easy, work effectiveness can be improved.

According to the present invention, it is possible to provide the high-frequency heating device which can prevent the front surface of the cover from moving in the vertical direction, which can prevent the cover from being obliquely attached to the front plate due to a deformation or an insufficient sandwiching of the flange of the front plate, and which is high in its quality of an external appearance.

• Fig. 1 is an exploded perspective view of a microwave oven in a first embodiment of the present invention.
• Fig. 2 is a perspective view under a state that a door is detached in the microwave oven of the first embodiment.
• Fig. 3 is a side view of a cover of the microwave oven of the first embodiment.
• Fig. 4 is a side view of a front plate of the microwave oven of the first embodiment.
• Fig. 5 is a side view showing a state that the cover of the microwave oven of the first embodiment is attached to the front plate.
• Fig. 6 is a sectional view taken along a line A-A of Fig. 5.
• Fig. 7 is an enlarged view of an engaging body of a microwave oven of a second embodiment.
• Fig. 8 is a perspective view under a state that a door is detached in a usual microwave oven.

A first invention provides a high-frequency heating device including: a heating chamber in which an object to be heated is placed; a front plate arranged in a peripheral edge of an opening part of the heating chamber; and a cover which covers the heating chamber and is attached to the front plate, wherein the front plate includes engaging bodies which suppress the vertical movement of the cover, and wherein pawls of the cover are partly cut out so as to meet the engaging bodies of the front plate so that the pawls of the cover are fixed in a vertical direction by the engaging bodies. Consequently, it is possible to prevent the cover from moving in the vertical direction, and also prevent the cover from being obliquely attached to the front plate due to a deformation or an insufficient sandwiching of the flange of the front plate

A second invention provides the high-frequency heating device according to the first invention, wherein an end face of the engaging body is formed to be round. Consequently, the resistance during the sandwiching is reduced. As a result, the attaching operation of the cover becomes easy, whereby work effectiveness can be improved.

Now, an embodiment of the present invention will be described below by referring to the drawings. The present invention is not limited by the embodiment.

Fig. 1 is an exploded perspective view of a microwave oven (a high-frequency heating device) in a first embodiment of the present invention. Fig. 2 is a perspective view under a state that a door is detached in the microwave oven of the first embodiment. Fig. 3 is a side view of a cover 1 of the microwave oven of the first embodiment. Fig. 4 is a side view of a front plate 4 of the microwave oven of the first embodiment.

As shown in Fig. 1 and Fig. 2, a cabinet 2 of the microwave oven (the high-frequency heating device) of the first embodiment includes a front plate 4 attached to a peripheral edge of an opening part of a heating chamber 3, a rear plate 5 provided in a rear part of the heating chamber 3, a bottom plate 6 and a cover 1 which covers an upper surface and right and left side surfaces of the heating chamber 3. An outer peripheral edge of the front plate 4 is bent inside. An upper flange 7 is formed in an upper part of the front plate 4. In a lower part, a lower flange 8 is formed. In right and left side parts, side flanges 9 are formed. Further, also in the rear plate 5, an upper flange 7 is formed in an upper part, a lower flange 8 is formed in a lower part, and side flanges 9 are formed in right and left side parts like the front plate 4.

As shown in Fig. 2, the cover 1 is formed by bending one flat plate to have a substantially U-shape. Further, in an upper part of a front side of the cover 1, an upper flange holding pawl 10 which sandwiches the upper flange 7 of the front plate 4 is formed as shown in Fig. 2 and Fig. 3. Further, in right and left side parts of a front surface of the cover 1, side flange holding pawls 11 which sandwich the side flanges 9 of the front plate 4 are formed as shown in Fig 2 and Fig. 3.

In the right and left side parts of the front plate 4, as shown in Fig. 4, engaging bodies 30 which fix the pawls 11 of the cover 1 in the vertical direction are formed. The pawls 11 of the cover 1 have forms cut out so as to meet the shapes of the engaging bodies 30.

Now, an assembly of the cabinet 2 will be described below by referring to Fig. 1. The lower flanges 8 of the front plate 4 and the rear plate 5 fixed to the heating chamber 3 are fixed to the bottom plate 6 by screws 20 to allow the front plate 4 and the rear plate 5 to stand upright. Then, the cover 1 formed and molded substantially in the shape of the character U is prepared and the cover 1 is slid forward by moving lower bent bodies 12 of the cover 1 along a lower surface of the bottom plate 6.

When the cover 1 reaches the most forward part, the upper flange 7 of the front plate 4 is sandwiched by and engages the pawl 10 formed in the upper part of the front side of the cover 1. At the same time, the side flanges 9 of the front plate 4 are sandwiched by and engage the pawls 11 formed in the right and left side parts of the front surface of the cover 1. At this time, as shown in Fig. 5 and Fig. 6, since the engaging bodies 30 formed in the side flanges 9 in the right and left side parts of the front plate 4 are arranged on an upper side of the pawls 11, the engaging bodies 30 suppress the vertical movement of the pawls 11 of the cover 1. After that, since an upper bent body 13 and side bent bodies 14 of the cover 1 shown in Fig. 1 abut on the rear plate 5, the cover 1 is fixed to the rear plate 5 by screws 20. In such a way, the cabinet 2 is completed.

In this embodiment, as shown in Fig. 7, an end face of an engaging body 30 is formed to be round so as to improve workability. Other structures of a cabinet 2 are the same as those of the first embodiment.

Since the end face of the engaging body 30 of the present embodiment is formed to be round, when a cover 1 is slid forward by moving lower bent bodies 12 of the cover 1 along a lower surface of a bottom plate 6, a resistance due to a contact of a pawl 11 of the cover 1 with the engaging body 30 can be reduced. As a result, since an attaching operation of the cover 1 is easy, work effectiveness can be improved.

The present invention is described in detail by referring to the specific embodiments, however, it is to be understood to a person with ordinary skill in the art that various changes or modifications may be made without deviating the spirit and scope of the present invention.

This application is based on Japanese Patent Application (Application No. 2011-278114) filed on December 20, 2011, and contents thereof are incorporated herein as a reference.

In the high-frequency heating device according to the present invention, the front surface of the cover can be prevented from moving in the vertical direction and the cover can be prevented from being obliquely attached to the front plate due to a deformation or an insufficient sandwiching of the flange of the front plate. Thus, the high-frequency heating device is useful as a high-frequency heating device high in its quality of an external appearance.

1:

Cover

2:

Cabinet

3:

Heating Chamber

4:

Front Plate

5:

Rear Plate

6:

Bottom Plate

7:

Upper Flange

8:

Lower Flange

9:

Side Flange

10:

Upper Flange Holding Pawl

11:

Side Flange Holding Pawl

12:

Lower Bent Body

13:

Upper Bent Body

14:

Side Bent Body

20:

Screw

30:

Engaging Body