JPS6380494A - Electric oven - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Use of Heat] The present invention relates to an electric oven used for heating and cooking food.

[Conventional technology]

Ovens using planar heaters whose heating wires are insulated with mica material have been known. A front sectional view of such an electric oven is shown in FIG. As shown in FIG. 4, the conventional electric oven has a sheet heater 3 in close contact with the outside of the wall surface 2 of the heating chamber 1, and a reflector plate 4 on the outside of the sheet heater 3.
The planar heater 3 is pressed and supported by the reflecting plate 4, and is fixed to the heating chamber wall surface 2 with screws 5. The heat insulating material 6 is provided outside the reflecting plate 4.

[Problem that the invention seeks to solve]

In the conventional electric oven described above, since the reflector plate 4 is in contact with the planar heater 3, the temperature of the reflector plate 4 rises, and the reflector plate 4 itself becomes a heat radiator. It has the disadvantage that its effectiveness is reduced. Furthermore, since the reflection plate 4 removes the heat emitted from the planar heater 3, the heating efficiency of the heating chamber 1 also decreases. In particular, in the case of a sheet heater made of mica material (with insulated heating wires), the insulation deterioration due to water vapor is greater than that of a sheathed heater, so unlike a sheathed heater, it cannot be installed inside the wall of the heating chamber 1. Since heating is performed through the wall surface 2, there is a problem in that it is difficult to increase heating efficiency.

Therefore, it is an object of the present invention to solve these problems of conventional heating ovens, and to improve the heating efficiency of electric ovens that use mica material to insulate heating wires and a surface. .

[Means for solving problems]

The present invention provides an electric oven equipped with a heating chamber for heating an object to be heated, a planar heater, a heat insulator, and a reflector.
The above-mentioned sheet heater is brought into close contact with the outside of the wall surface of the above-mentioned heating chamber,
This electric oven has a heat insulating material placed on the outside of the sheet heater, and a reflector placed on the outside of the heat insulating material.

The above-mentioned planar heater preferably has a structure in which a plate-shaped mica material wrapped with heating wire is sandwiched between two plates of mica material.

The heat insulating material may be made of glass fiber, asbestos, etc., and the reflective plate may be made of conventional sheet metal material or aluminum foil.

[Function] The electric oven of the present invention has a structure in which a heat insulating material is interposed between the sheet heater whose heating wire is insulated with mica material and the reflector plate, so that the temperature of the reflector plate does not rise as high as in the conventional structure. It is fully effective as a reflector and improves thermal efficiency. In addition, because insulation materials have low thermal conductivity,
Even if it is in contact with the sheet heater, a large amount of heat is not taken away from the sheet heater, and therefore the heating efficiency of the heating chamber of the sheet heater can be greatly improved.

〔Example〕

An embodiment of the electric oven of the present invention will be described below with reference to the drawings. FIG. 1 is a front sectional view of an electric oven according to an embodiment of the present invention, and FIG. 2 is an exploded explanatory view showing the configuration of a sheet heater.

In FIG. 1, reference numeral 1 denotes a heating chamber, and a planar heater 3 is tightly fixed on the outside of the heating wall surface 2 by screws 7 and nuts 8. A heat insulating material 6 made of glass fiber is placed on the outside of the planar heater 3, and a reflecting plate 4 made of a sheet metal material or aluminum is placed on the outside thereof.

As shown in FIG. 2, the plate-shaped heater 3 has a heating wire 3b such as a nichrome wire wrapped around a plate-shaped mica material 3a, and the plate-shaped mica material 3a wrapped around the heating wire 3b is shaped like a sandwich. It is sandwiched between two other plate-shaped mica materials 3C and 3d. Each mica material 3a.

3C and 3d have through holes E that match those squares,
, , F, G, and H, and when fixing the planar heater 3 having the above configuration to the wall surface 2 of the heating chamber 1, insert the screws 7 into these through holes E, F, G, and H. Secure with nut 8. Note that 9 shown in the figure is a washer, which is a nut 8.
The depth is provided to prevent the nut 8 from digging into the mica material when tightened.

According to the above-described configuration, since the reflector plate 4 is provided via the planar heater 3 and the heat insulating material 6 with low thermal conductivity, it is possible to prevent the temperature of the reflector plate 4 from rising, thereby preventing heat radiation. The function of the reflecting plate 4 can be fully demonstrated.

Further, the main component with good thermal conductivity that is in contact with the planar heater 3 is only the wall surface 2 of the heating chamber 1, and the heating efficiency of the heating chamber 1 by the planar heater 3 is improved. Furthermore, since the planar heater 3 is closely fixed directly to the wall surface 2 by the screws 7 and nuts 8, the heating efficiency can be further improved in this respect as well.

The temperature of the heating chamber 1 of the electric oven in the above embodiment is room temperature (2
Figure 3 shows the relationship between the temperature and the time required to reach a predetermined temperature from 0°C. For comparison, the relationship between temperature rise and time in the conventional electric oven shown in FIG. 4 is also shown in FIG.

From Figure 3, a heating chamber with a volume of 16,000 ej has a power consumption of 1.
1 was heated using a W sheet heater under the same conditions as the conventional product and this example, and the temperature ranged from 20°C to 170°C.
While it takes 8 minutes for conventional products,
In this example, it can be seen that 4 minutes is sufficient.

I6 In the above embodiment, screws 7 and nuts 8 were used to construct the sheet heater 3 and fix it to the wall surface 2, but instead, a highly heat-resistant adhesive such as a ceramic adhesive was used. It may be fixed.

〔Effect of the invention〕

In the electric oven according to the present invention, the reflector is not provided close to the sheet heater, and a heat insulating material is interposed between them, so that only the wall surface of the heating chamber is efficiently heated, resulting in improved heating efficiency. Improved. Furthermore, since the temperature of the reflector itself is prevented from rising, it can fully exhibit its effect as a reflector that blocks heat radiation. Therefore, the required heating time can be reduced compared to an electric oven of the same standard with a conventional configuration, and the performance of the electric oven can be improved.

[Brief explanation of the drawing]

Fig. 1 is a front cross-sectional view of an electric oven according to an embodiment of the present invention, Fig. 2 is an exploded explanatory view showing the configuration of a planar oven, and Fig. 3 is a graph showing its characteristics. Yes, 4th
The figure is a front sectional view of a conventional electric oven. 1-m-heating chamber, 2-m-wall surface, 3-1-plane heating Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. In an electric oven equipped with a heating chamber for heating an object to be heated, a planar heater, a heat insulating material, and a reflector, the planar heater is closely attached to the outside of the wall of the heating chamber. An electric oven characterized in that a heat insulating material is placed on the outside of the sheet heater, and a reflective plate is placed on the outside of the heat insulating material. 2. The electric oven according to claim 1, wherein the planar heater has a structure in which a plate-shaped mica material wrapped with a heating wire is sandwiched between two plates of mica material.