JPH0444964Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The invention relates to a microwave oven with a grill heater.
This relates to a heater that moves diagonally up and down.

<Prior art> The heater in a conventional microwave oven equipped with a grill heater is rotatably disposed within the heating chamber.
When not using it as a grill heater, place the flat heat generating part upright along the back wall of the heating chamber, and when using it as a grill heater, rotate the heat generating part counterclockwise so that it approaches the object to be heated. The location was set.

If the heat generating part of the grill heater is set horizontally, the entire surface of the object to be heated will be heated relatively uniformly, but if the heat generating part of the grill heater is set diagonally, the surface of the object to be heated will be relatively uniformly heated. There was a problem in that it was difficult to heat uniformly because the distances and facing angles to various parts of the object surface were different.

On the other hand, in actual use, the heating section is more often set diagonally than horizontally, and there has been a strong demand for a solution to the above-mentioned problem.

On the other hand, it is easy to move the heat generating part up and down while keeping it horizontal, but since it is necessary to install a microwave power supply in the center of the ceiling of the heating chamber, the heat generating part of the heater can be moved up and down in the center of the ceiling of the heating chamber. It cannot be set to Therefore, it is necessary to set the heater on a part other than the center of the heating chamber ceiling and lower it vertically from that part, but when the heating part of the heater is set at the bottom of the heating chamber, the object to be heated is heated from above the center. This results in extremely uneven heating.

Therefore, the applicant provided a heater drive mechanism that moves the horizontal plane heater obliquely downward from the rear part of the microwave power supply part in the center of the ceiling of the heating chamber.
A microwave oven with a heater that always provides uniform browning and heating because the flat heater faces the object to be heated in a horizontal state, whether in a high or low position.
No. 118255 has been filed.

Hereinafter, one embodiment will be described based on the drawings.
2 and 3 are a front perspective view and a side sectional view of a main part for explaining the arrangement and moving direction of the planar grill heater.

11 in the figure is a heating box that constitutes a heating chamber,
A flat grill heater 1 is installed on both side walls of the heating box 11.
Elongated hole 1 for moving the terminal part of 2 in the direction of the arrow
3 is provided. 14 is a waveguide that guides the magnetron's radio waves to the power supply port 15 in the center of the ceiling wall of the heating box, and 16 is a heater that is formed by drawing the rear part of the power supply port 15 in the ceiling wall of the heating box to match the size of the heater 12. The storage section 17 is a rear space of the heating chamber that accommodates a hot air circulation cooking device (not shown).

Next, the shape and structure of the planar grill heater 12 will be explained based on FIGS. 4 and 5. Fourth
The figure is a vertical cross-sectional view of the main part, and the heat generating part of the planar grill heater 12 consists of a sheathed heater 12a bent into a meandering shape, a reflector 12b disposed above it, and a ceramic heat insulating material 12c covered with a metal cover. (upper) 12d and a metal cover (lower) 12e.
As shown in the bottom view of FIG. 5, a slit hole 12f is formed in the sheathed heater 12a to directly radiate the heat rays of the sheathed heater 12a (including the heat rays reflected by the reflection plate 12b) to the object to be heated. The slit hole 12f is formed in a position where the sheathed heater 12a is difficult to see from an external perspective, and the size of the slit hole 12f is such that it prevents the penetration of microwaves, thereby preventing discharge from occurring due to the penetration of microwaves. This prevents microwave loss. Further, the heater side of the reflector plate 12b is coated with far-infrared paint so that far-infrared rays are radiated to the object to be heated.

The heat generating section radiates uniform heat rays intensively toward the object to be heated, contributing to uniform and efficient grill heating. In addition, 12g in FIG. 4 is a heat-shrinkable tube, which exhibits an insulating function when passed through the elongated hole 13 provided in the heating box 11. Further, the metal cover (upper) 12d and the metal cover (lower) 12e are joined together by curling caulking around the entire circumference except for the sheathed heater take-out portion, thereby preventing microwaves from entering. Furthermore, metal cover (top) 12d
Alternatively, a small hole (not shown) is provided on the front side surface of the metal cover (lower) 12e to inform the user that the heater 12a is red-hot.
Care has been taken to prevent users from touching it carelessly.

Next, a heater drive device that moves the heater 12 up and down will be explained. As shown in FIG. 6, the heater drive device 18 includes a roller (upper) 20 and a roller (lower) 21 that are pivotally supported above and below a steel plate box 19, and the roller (upper) 20 and roller (lower). It consists of a metal (thin plate) belt 22 that is hung on the metal belt 21, and a heater mounting bracket 23 that is spot-welded to the metal belt 22.
An elongated hole 24 that matches the elongated hole 13 on the side wall of the heating box is bored in the mounting surface (mounting surface to the side wall). Matching pawl holes 26 are drilled at a predetermined pitch, and oval-shaped holes 27 are drilled through which the ends of the heaters 12 are inserted.

The bottom side of the metal belt 22 is made to slide against the bottom surface in order to prevent leakage of radio waves from the elongated hole 24. By sliding the long hole 24, the metal belt 22
This will reduce radio wave leakage.

As shown in FIG. 7, the heater driving device 18 is constructed by inserting the end of the heater 12 pulled out from the elongated hole 13 of the heating box 11 into the elongated hole 24 of the box 19 and the hole 27 of the metal belt 22. Long hole 1
3 and the elongated holes 24 of the box 19, and are attached to both side walls of the heating box 11. and heater 12
The end of the box is fixed to a heater fitting 23 fixed to the metal belt 22, and a lead wire 28 passing through the box is connected to the terminal, and then a metal cover 29 is attached.

Next, a description will be given of a device that transmits driving force to the left and right heater drive devices in order to synchronize the left and right ends of the heater 12 and move them up and down.

Fig. 8 is a schematic explanatory diagram of the driving force transmission mechanism seen from the front of the microwave oven, and Fig. 9 is a three-dimensional perspective view of the belt hook of the driving force transmission means seen from the rear of the microwave oven. is the heater, 18,18
are heater drive devices attached to both sides of the heating box 11, 20 is a roller (upper), 21 is a roller (lower), 2
2 is a metal belt.

A gear 21a is attached to the rear end of the roller (lower) 21, and a gear 21a is attached to the gear 21a so that the inner sides of the left and right metal belts 22, 22 move up and down synchronously (the left and right rollers (lower) 21a , 21a in the opposite direction), a single rubber belt 32 having teeth on one side is stretched through a rotatable intermediate roller 30 and an intermediate gear 31. 33 indicates a half-turn twist of the rubber belt 32 for synchronously rotating the left and right rollers (lower) 21, 21 in opposite directions.

When the reduced rotational force of a motor (not shown) is transmitted to the front end of either one of the lower rollers 21, the metal belt 22 and the rubber belt 32 are displaced as shown by the arrows.

<Problems to be solved by the invention> The above is the heater drive mechanism for a microwave oven with a heater, which was filed in Utility Application No. 118255/1982.
As shown in FIG. 10 in the cross-section taken along the line A-A' in the figure, if a burr is formed in the claw hole 26, an electric discharge occurs in this part and the metal belt 22 and box 19 are arc welded, and the metal belt I found out that there was a problem where the parts could stop sliding.

<Means for solving the problem> The "burr" 26a of the metal belt 22 or the metal belt sliding object (box 19) existing near the elongated hole 13 (elongated hole 24 of box 19) is caused by microwave radio waves. A welding prevention groove 28a is provided on the metal belt or the metal sliding object to prevent arc welding.

<Function> The "burr" 26a of the metal belt 22 or the object on which the metal belt slides (box 19) and the object on which the metal belt slides (box 19) or the metal belt 22 are insulated with air, so that no arc discharge occurs.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a sectional view taken along the line A-A' according to the present invention, which corresponds to FIG. 10 of the conventional example, and the same or corresponding parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

The most distinctive feature of the present invention is the provision of welding prevention grooves to prevent "burrs" from being arc welded by microwave radio waves. ``Bali''
Band-shaped bulges 28, 28 are provided on the bottom surface of the box 19 to form a welding prevention groove 28a so that the box 26a does not come into contact with the bottom surface of the box 19.

The welding prevention groove may be formed by providing a band-shaped bulge in the claw hole 26 portion of the metal belt 22, and the "burr" is not limited to the "burr" 26a generated around the claw hole 26 of the metal belt 22. , "burrs" around the elongated hole 24 drilled in the bottom of the box 19, etc., which may be arc-welded by microwave radio waves.
Of course, Box 19 also applies to
Of course, the present invention can also be applied to a device that does not have a bottom surface and the side wall of the heating chamber and the metal belt 22 slide directly.

<Effects> The present invention solves the problem that the metal belt does not slide due to arc welding.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the sliding relationship between the bottom surface of the box and the metal belt according to the present invention, and Figs. 2 and 3 are front perspective views and side sectional views of main parts to explain the arrangement and moving direction of the heater. , FIG. 4 is a vertical sectional view of the main part of the heater, FIG. 5 is a bottom view of the main part of the heater, FIG. 6 is a perspective view of the heater drive device, and FIG. 7 is a diagram of the installation relationship between the heater drive device and the heating box. , Fig. 8 is a schematic explanatory diagram of the driving force transmission mechanism seen from the front of the microwave oven, Fig. 9
The figure is a three-dimensional perspective view of the belt hook seen from the rear of the microwave oven, and FIG. 10 is a diagram showing the sliding relationship between the bottom of the box and the metal belt in a conventional example. Code, 12...Grill heater, 13...Elongated hole,
18... Heater drive device, 19... Box, 2
2... Metal belt, 24... Long hole, 26a... Burr, 28a... Welding prevention groove.

Claims (1)

[Claim for Utility Model Registration] A long hole for moving the end of the grill heater is provided in the side wall of the heating chamber, and a metal belt is slidably provided to cover the long hole and move the end of the grill heater. In a microwave oven, welding prevention grooves are installed on the metal belt or the metal belt sliding object to prevent arc welding of "burrs" on the metal belt or the metal belt sliding object that exist near the elongated holes due to microwave radio waves. A microwave oven with a heater.