JPS58195716A - High frequency heating device - Google Patents

Abstract

PURPOSE:To improve an assembling efficiency and safety, by a method wherein frames having an approximately ?-shape in cross section are mounted to 3 sides of an outer frame of a door covering an open face of a heating chamber, while a front screen is housed in a channel formed of the frames, and it is elastically held by the elastic projection formed on each of the frames. CONSTITUTION:A door 5 for opening and closing an open face 3 of a heating chamber 2 is formed such that an outer door frame 6 and a middle door frame 7, all made of a metal, are united together as a unit, and a metal screen 8 and an inner screen 10 made of glass are positioned between the nip formed by a middle door frame 7 and an inner door frame 6. In which case, a right front door frame 24 and a left front door frame 25, and a lower front door frame 26, all having an approximately ?-shape in cross section, are monolithically adhered to the front of the outer door frame 6 by a spot welding. After a front screen 16 is inserted into a ?-shape channel formed of the frames 24-26, an upper front door frame 27 is pressed in, and approximately ?-shaped projections, formed on the frames 24, 25 and 27 and having elasticity, are brought into contact with the back of the front screen 16 to support the screen 16 with no clearance, thereby eliminating backlash.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to means for holding a screen on the front surface of a door of a high-frequency heating device.

A door is provided on the opening surface of the heating chamber of a high-frequency heating device so that it can be opened and closed freely.The door not only prevents the high frequency waves generated inside the heating chamber from leaking outside, but also protects the objects to be heated inside the heating chamber. The structure allows you to see the heating state from the outside. Furthermore, in recent years, doors have added design elements to their products, and doors with screens made of glass or plastic on the front have become available.

However, the conventional structure for holding the front screen of the door is complicated due to the large number of parts, and there are many problems in the structure for protecting the front screen from impact. Regarding a conventional example, the configuration of a high frequency heating device equipped with a vertically swinging door will be explained below with reference to FIGS. 1 and 2.

A heating chamber 2 in the main body 1 is equipped with a magnetron that generates high frequency waves and a high voltage power supply (not shown), and a door 6 is provided opposite the opening surface 3 of the heating chamber and rotatable about a rotation shaft 4. The door 6 is constructed by spot welding a metal outer door frame 6 and a door inner frame 7 into one piece, and is made of glass with a metal screen 8 consisting of a group of small holes and a U-shaped rubber frame 9 on the outer periphery. An inner screen 1o is held between a metal door inner frame 11 whose surface is treated with an insulating material and a door middle frame 7 by screws 12. The space formed by the door outer frame 6 and the door inner frame 11 is a radio wave attenuation groove 13, and a cover 14 made of a low dielectric material or heat-resistant plastic is held at the entrance thereof.

A plastic door outer frame 16 is arranged on the outside of the single gal 6, and an outer screen 16 made of resin such as acrylic or reinforced glass is sandwiched between the door outer frame 6 and the door outer frame 16. There is. The door outer frame 15 is fixed from the inside of the door outer frame 6 with screws 17. A part of the podium 18 and a lower sash 19 are arranged on the periphery of the door 6 in parallel with the door outer peripheral frame 16, and these are all made of metal material. 20 is a handle, 21 is a timer knob for setting heating time provided on the operation panel 22, and 23 is a heating start button.When heating the object to be heated with high frequency, set the timer knob 21 to the required time. , Heating, press the start button 23 1: Heating starts. The structure is such that the generation of high frequency waves stops when the tie or marr breaks or when the door 6 begins to open during heating.

By the way, the outer screen 16 of the high-frequency heating device and the outer peripheral frame 16 of the door are required to have improved heat resistance and design as products become more sophisticated, diversified, and combined with open functions. As a result, the structure becomes complicated, the number of parts increases, and the number of man-hours required for manufacturing and service increases, which increases costs.

Furthermore, in order to make the outer screen 16 difficult to break even when subjected to an external impact force, when the material of the screen is glass, it is generally subjected to a strengthening treatment such as thermal strengthening. However, in the case of glass, although it is somewhat strong against large curvature, it is extremely susceptible to breaking when external force is locally concentrated.

Therefore, if the outside screen 16 is held in contact with the surface of the metal door frame 6 like the conventional outside screen 16, the amount of damage to the outside screen 16, especially the part that is in contact with the door frame 6, will increase.
If exposed to strong impact force, it will be extremely dangerous, □.

It had a tendency to break easily7, which was considered a safety issue.

Furthermore, taking into account that the glass plate thickness varies by 10%, the gap between the door outer frame 6 and the door outer frame 16 is configured as follows:
It is structurally impossible to hold the outer screen 16 without rattling, which also causes a drop in product value.

The present invention solves the above-mentioned problems in the conventional example, namely, reduces the number of parts and improves workability, protects the outer screen from impact force to prevent cracking, and further prevents the outer screen from rattling. By doing so, safety and
It is possible to provide a high-frequency heating device with an increased number of door structures that can improve marketability, diversify products, and satisfy design requirements.

An embodiment of the present invention will be described below with reference to FIGS. 3 to 6 using an example of a high-frequency heating device equipped with a vertically swinging door.

A door 6 is provided opposite to the opening surface 3 of the heating chamber 2 and rotatable about a rotating shaft 4. The structure of the door consists of a metal door outer frame 6 and a door inner frame 7 that are integrally formed by spot welding.
A metal screen 8 consisting of a group of small holes and an inner screen 1o made of glass with a U-shaped rubber frame 9 on the outer periphery are placed between the metal door frame 11 whose surface is treated with an insulator and the door middle frame 7. It is held by screws 12. The space formed by the door outer frame 6 and the door inner frame 11 is a radio wave attenuation groove 13, and a cover 14 made of a low dielectric material or heat-resistant plastic is held at the entrance thereof.

- On the front side of the gull outer frame 6 is the door front frame right 24. Door front frame left 26.
The lower door front frame 27 is integrated by spot welding and painted. The right door front frame 24 and the left door front frame 26 are bilaterally symmetrical, and have a substantially U-shaped cross section. Lower door frame 26
is configured to be on the same plane as the right door front frame 24 and the left door front frame 26, and the lower side thereof is an inclined surface. This is to reduce the amount of radio wave leakage by reducing the gap between the lower door front frame 26 and the lower sash 19.

The outer screen 16 is located on the right side of the door front frame 24. It is inserted and held in the U-shaped groove formed by the left 26 and the bottom 26,
The width a of the groove is larger than the thickness b of the outer screen. This is because when the outer screen 16 is made of tempered glass, it is necessary to allow a variation in thickness of ±10% and a distortion in the plane of the glass of about 0.3 inch. Therefore, in order to prevent the outer screen 16 from rattling, the lower ends of the spot welding surfaces of the right door frame 24 and the left door frame 26 are formed into a substantially dogleg shape to provide elasticity, and are brought into contact with the back surface of the outer screen 16. In addition to absorbing the looseness of the lower part of the outer screen 16, the door front frame upper part 27 having a protrusion with a substantially doglegged cross section is press-fitted, and the protrusion is brought into contact with the back surface of the outer screen 16, thereby absorbing the looseness of the upper part. It absorbs the heat. In particular, the upper door frame 27 has a substantially doglegged protrusion near the center, and by press-fitting the elastic protrusion between the door outer frame 6 and the outer screen 16, it eliminates the gap and eliminates water and dust. This prevents the glass from entering and also covers the cut surface of the glass so that it cannot be seen. Door front frame top 27
After press-fitting, when the handle 2o is fixed with a screw, the door front frame comes into contact with the base of the handle 20, and the outer screen 16 has a structure that does not shift. ,,,・
, 1°・l: [・ Figure 6 shows the assembled door.

ヮ、4□. 1.5, ■ The gap between the outer screen and the door front frame, the right frame, the left frame, and the bottom is almost unaffected by variations in the thickness of the outer screen and distortion of the plane. It can be eliminated, has good design performance, and increases product value.

■ The outer screen is held in place by elastic bent-shaped protrusions on the right side of the door front frame, the same on the left side, and the same as above, so that it does not come into contact with the front of the door outer frame, so even if the outer screen receives an impact, it will not touch the outside screen. Since this elastic, roughly-shaped protrusion can absorb impact, there is almost no possibility of damage such as cracking to the outer screen.

■ Among the parts that make up the door, the parts that hold the outer screen are all integrated with the door frame and are not painted, so the number of parts is small, simplifying assembly work and management. be.

Effects such as this can be obtained.

[Brief explanation of drawings]

:1 Fig. 1 is an external perspective view of a conventional high-frequency heating device, Fig. 2 is a sectional view of the door, and Fig. 3 is a cross-sectional view of the door of a high-frequency heating device according to an embodiment of the present invention. A sectional view, FIG. 4 is an external perspective view of the opening door, and FIG. 5 is an external perspective view of the door with the outer screen attached. 6...Door outer frame, 16...Outside screen, 2゜...Handle, 24...Door front frame right, 25... Door front frame left, 26...Door front frame F127...Top of door front frame. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 1 Figure 3

Claims (1)

[Claims] a heating chamber that is supplied with high-frequency power and has an opening; a door that covers the heating chamber so as to be openable and closable; and at least a pair of opposing sides provided on three sides of the front periphery of the door that are approximately U-shaped in cross section. A high-frequency heating device comprising: a frame body for holding a front screen; and an elastic body provided so as to come into contact with a peripheral edge of a back surface of the front screen.