JPH06272870A - Door member for microwave oven and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a door member for a microwave oven, large in the degree of freedom of designing, prominent in the intercepting property aginst radio waves as well as the interior-visible property and simple in assembling work. CONSTITUTION:A perforated metallic layer 17, having small holes 16, is made in one side of a supporting film 15 constituted of a synthetic resin having transparency, then, a protecting layer 18 made of transparent synthetic resin is formed so as to cover the perforated metallic layer 17 and, thereafter, the protecting layer 18 is integrated with the supporting film 15 through thermal fusion welding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a door material for a microwave oven and a method for manufacturing the same.

[0002]

As is well known, the door of a microwave oven is required to have a function of shielding electromagnetic waves and a function of allowing the inside of the microwave oven to be seen through from the outside. Therefore, in the conventional microwave oven, as shown in FIG. 7, a wire net (mesh), a punching sheet, or the like is provided between the outer protective plate 1 and the inner protective plate 2 made of flat glass or a transparent synthetic resin plate. A flat plate-like window plate member 4 is sandwiched between the electromagnetic wave shielding plate or sheet 3 and the window plate member 4 is assembled to the door frame 5 from the back side to form a microwave oven door.

[0003]

However, when a wire net or a punching sheet is used as an electromagnetic wave shielding material, there are many restrictions on the shape that can be processed, and the degree of freedom in design is small.
For example, even if a microwave oven is designed with a curved surface, if the conventional structure is adopted as it is, the door portion cannot be formed with a curved surface, resulting in an unbalanced design as a whole. In particular, since the door is most noticeable to the user, the design of this door is so important that it affects the design of the entire microwave oven. In addition,
When a flat window material is used inside and the front surface of the door frame is curved with another member, the thickness of the door becomes thicker, and the volume of the internal cooking chamber is increased and it is compact as a whole. However, it cannot be put to practical use at present. Also, many components such as the outer protection plate, the inner protection plate, the electromagnetic wave shielding material, the door frame, the hinge, and the handle have to be separately assembled and then assembled, so that the assembly work is troublesome and the work efficiency is high. Is difficult to raise. Therefore, cost reduction is not easy. Furthermore, it is practically difficult for wire mesh and punching sheet to freely design the weaving method of wires and the shape and arrangement (pattern) of punch holes, so that it is possible to improve internal visibility and electromagnetic wave shielding property. It's extremely difficult.

[0004]

Therefore, the present invention has been proposed in view of the above, and a porous metal layer is formed on one surface of a support film made of a resin having a light-transmitting property, and then the support film is molded. A protective layer is integrally formed on one surface of the support film by inserting the mold into a mold and covering the porous metal layer with a synthetic resin that is heat-welded to the support film.

[0005]

[Function] The support film having the porous metal layer formed on one surface is inserted into the molding die, and the protective layer is integrally molded with the synthetic resin so as to cover the porous metal layer, so that the shape of the protective layer can be freely designed. Moreover, the porous metal layer is reliably protected by the protective layer.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the microwave oven 11 shown in FIG. 1, the door 12 is designed to have a curved surface so as to give the viewer a soft impression. The door 12 is formed by bulging the front portion forward with a gentle curved surface, and bending the upper, lower, left, and right side edges of the front portion rearward, so that the hinge portions 13, 13 are vertically arranged on one side.
Is provided so as to project rearward, and a handle 14 is provided on the front portion of the free end. The door 12 is integrally formed including the handle 14 and the hinge portion 13 without separately forming the door frame and the window plate material.

Such a door 12 has a large number of small holes 1 on one side of a support film 15 made of a synthetic resin having a light-transmitting property.
A porous metal layer 17 having 6 ... is formed, and a protective layer 18 is formed of a translucent synthetic resin so as to cover the porous metal layer 17 on one surface of the support film 15 and is molded into a predetermined shape. When forming the protective layer 18, the hinge portions 13 and 13 and the handle 14 are simultaneously formed.

The support film 15 is a film made of a material having impact strength and heat resistance, and has a thickness of 0.2 to 0.
A 3 mm polycarbonate plastic film is preferable. The porous metal layer 17 can be formed on one surface of the support film 15 by a known metal thin film forming means such as vapor deposition, etching, sputtering, thermal spraying and electroless plating. And the porous metal layer 1
The material of 7 may have an electromagnetic wave shielding property, and may be, for example, aluminum, gold, silver, copper, or an alloy thereof. In addition, the innumerable small holes 16 formed in the porous metal layer 17 are holes having a size capable of blocking electromagnetic waves, and what if the object on the opposite side can be visually recognized through the small holes 16 ... It may be set to. For example, the shape is not limited to a round hole, and may be a honeycomb shape, a lattice shape, a wavy slit, or the like.

The protective layer 18 is a plate-shaped layer formed of a synthetic resin having a property of being heat-welded to the support film 15, for example, polycarbonate plastic, and is transparent or colored in a transparent state like the support film 15. May be.

Microwave oven door 12 having such a structure
In order to form a porous metal thin film on one surface of the support film 15 by, for example, vapor deposition, first, as shown in FIG. 2, metal is not deposited on one surface 15b of the support film 15 in the next metal vapor deposition step. Part, that is, the small hole 16 for see-through
The Celite primer 19 ... In this embodiment, the sealite primer 19 has a dot shape such as a circle having a diameter of 3 m / m or less, and the support film 1
Although it is attached so as to be uniformly dispersed on one surface 15b of No. 5, as described above, it is not limited to a dot shape, and a line pattern such as vertical and horizontal or diagonal lattice stripes or a honeycomb pattern is appropriately used. Can be selected. It should be noted that this attachment can be performed precisely using a printing technique.

When the celite primer 19 attached in this way is dried, a metal such as aluminum is vapor-deposited on one surface 15b of the support film 15 as shown in FIG. One side of
5b is entirely covered, and then the support film 15 is washed with water. By this washing with water, the vapor-deposited metal layer 20 adhered on the celite primer 19 ... Is peeled off, and the peeled off portion becomes small see-through holes 16 ...
Only the vapor-deposited metal attached to b remains. Therefore, the porous metal thin film 17 can be formed on the one surface 15b of the support film 15.

Next, the support film 15 is cut according to the dimensions of the door 12 to be manufactured, and is inserted into the upper and lower molding dies 21 and 22 to form the door 12, and the dies 21 and 2 are formed.
The synthetic resin injected into the protective layer 18, the hinge portion 13,
13 and the handle 14 are formed, and the formed protective layer 18 and the inserted support film 15 are integrated to form the door 12
And When the protective layer 18 is molded, the synthetic resin of the protective layer 18 and the support film 15 are brought into contact with each other through the remaining portion of the vapor-deposited metal, that is, the small holes 16 ... A molding method such as injection or gas assist injection is used for such molding, and it is preferable to form the protective layer 18 while pressing the resin on one surface of the support film 15 at a low pressure while injecting.

Although the door 12 is manufactured by integrally molding the one-piece door material in the above-described embodiment, the door material for the microwave oven according to the present invention is not limited to this, and the door frame and the window plate material are not limited thereto. May be manufactured separately, and the door material according to the present invention may be assembled as a window plate material into a door frame to form a door.

For example, the door 1 for the microwave oven shown in FIG.
2'is a frame-shaped door frame 23 having a window portion, and the door frame 23
Plate material 24 attached so as to close the window part of the
The door frame 23 is provided with a hinge portion (not shown) which is a connecting member with the main body 11 'and a handle.
On the other hand, the window plate member 24 is formed by molding the door member according to the present invention into a predetermined shape, and the front surface portion that closes the window portion is a convex shape that gently bulges forward in accordance with the curved surface of the door frame 23. The peripheral edge portion fixed to the door frame 23 is formed with a rib 25 or is bent to ensure sufficient rigidity.

Also in the case of manufacturing the door material used for the window plate material 24 of this embodiment, the porous metal layer 17 is formed on one surface of the support film 15 and the support film 15 is formed in the same manner as in the above embodiment. Is inserted into the molding dies 21 and 22,
The protective layer 18 is made of synthetic resin so as to cover the porous metal layer 17.
Are formed and integrally molded into a predetermined shape.

[0016]

As described above, according to the present invention, since the porous metal layer is formed on the support film, the shape and pattern of the small holes can be freely designed by means such as vapor deposition, and the inside can be visually confirmed. And the electromagnetic wave shielding property are easily improved. And, since this support film is inserted into a molding die to integrally mold the protective layer, it can be molded into a desired shape such as a curved shape, and the degree of freedom in designing the door or window of the microwave oven is reduced to the conventional one. It can be increased much more than anything. Therefore, according to the present invention, even if an innovative design other than the flat plate shape, which has hitherto been impossible due to the structural limitation of the door, is not limited to the flat plate shape in the structure, it can be freely adopted. And the product value of the microwave oven can be improved in terms of design. Further, according to the present invention, the number of parts of the door of the microwave oven can be significantly reduced compared to the conventional one, and the work efficiency can be improved because the assembly process can be reduced and the work can be simplified. You can Moreover, when the door material according to the present invention is used, the thickness of the door can be reduced, which contributes to simplification and weight reduction of the structure of the door itself.

[Brief description of drawings]

FIG. 1 is a perspective view of a microwave oven.

FIG. 2 is a cross-sectional view showing a state where a celite primer is attached to a support film.

FIG. 3 is a cross-sectional view showing a state in which metal is vapor-deposited.

FIG. 4 is a cross-sectional view showing a state in which vapor-deposited metal on a celite primer is removed by washing with water.

FIG. 5 is a cross-sectional view of a molding die in which a support film is inserted.

FIG. 6 is a cross-sectional view showing a state in which the door member according to the present invention is assembled to a door frame as a window plate member.

7A and 7B are perspective views showing a configuration of a conventional microwave oven door, in which FIG. 7A is an exploded perspective view of a window plate member, FIG. 7B is a perspective view of the window plate member, and FIG. It is a perspective view of the microwave oven provided with the assembled door.

[Explanation of symbols]

 11 Microwave Oven 12 Door 15 Support Film 16 Small Hole 17 Porous Metal Layer 18 Protective Layer 19 Celite Primer 20 Evaporated Metal Layer 21,22 Molding Mold 23 Door Frame 24 Window Plate Material

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mutsuro Kurosaki 1 184 Maioka-cho, Totsuka-ku, Yokohama-shi, Kanagawa 1 Nifco Co., Ltd.

Claims (3)

[Claims] 1. A support film made of a synthetic resin having a light-transmitting property is formed with a porous metal layer on one side, and a transparent synthetic resin protective layer is formed so as to cover the porous metal layer and integrated. The door material for microwave ovens characterized by 2. A support film formed by forming a porous metal layer on one surface of a support film made of a translucent resin, and then inserting the support film into a molding die to cover the porous metal layer. A method of manufacturing a door material for a microwave oven, which comprises integrally forming a protective layer on one surface of a support film with a synthetic resin that is heat-welded with. 3. A support film made of a synthetic resin having a light-transmitting property is provided with a porous metal layer on one side, and then the support film is inserted into a molding die to cover the porous metal layer. A method of manufacturing a door member for a microwave oven, which comprises integrally forming a protective layer on one surface of a supporting film with a synthetic resin heat-welded to the film and simultaneously forming a hinge part and a handle part.