JPH0311073B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high-frequency heating device that improves cooking performance through uniform heating by providing a bulge on the bottom surface of the heating chamber by means of a diaphragm or the like. It is.

Structure of conventional example and its problems For example, in a conventional high-frequency heating device having a turntable driven by a shaft, in order to transmit the driving force of the shaft, the turntable 1 has a thick wall, as shown in FIG. It is common to have a structure in which a large portion 2 is provided, and a fitting portion 3 is provided in the shape of a shaft.
Further, the thick portion 2 is easy to mold,
In order to provide sufficient strength, it is often spread over a wide range to the extent that it affects cooking. The dielectric constant of the turntable is greater than that of air, so
Since the apparent distance between the bottom of the heating chamber and the object to be heated in the microwave is uneven, uniform heating cannot be achieved.

Furthermore, a high-frequency heating device having a turntable driven by a shaft is generally equipped with a roller that supports and rotates the turntable in order to withstand uneven loads. Conventionally, as shown in FIG.
A roller aperture 8 is installed on the bottom surface 4 of the heating chamber in order to fix it on the bottom surface 4 of the heating chamber or to arrange it in a ring shape.
has been established. For this reason, the shape of the drive unit 9 allows foreign substances such as water and oil to easily flow into the drive unit 9 during cooking, and if foreign substances enter the drive unit, it may cause insulation breakdown of the motor, prevent smooth rotation of the shaft, or flow out onto the cooking table. It may cause such things as In addition, due to the roller arrangement, the shaft 6 almost protrudes from the bottom surface 4 of the heating chamber, so it may come into contact with the turntable 1 when it is taken out or put in.
Since the area exposed to microwaves is large, there is a high risk of damage due to absorption of microwaves.

Purpose of the Invention The present invention solves the above-mentioned conventional drawbacks, and aims at uniform heating by keeping the apparent distance between the bottom of the heating chamber and the object to be heated by microwaves constant.

Structure of the Invention In order to achieve the above-mentioned object, the high-frequency heating device of the present invention provides ridges by means of apertures or the like corresponding to parts of the turntable with different wall thicknesses, so that microwaves can The structure is such that the apparent distance between the parts of the turntable is the same as that of parts other than parts of the turntable with different thicknesses.

By keeping the apparent distance between the bottom of the heating chamber and the object to be heated in the microwave to a constant state regardless of changes in the thickness of the turntable, the object to be heated can be heated evenly. can be,
The structure that prevents foreign matter from entering the drive section has the effect of enabling smooth transmission of driving force, and has the effect of reducing the protrusion of the drive shaft into the heating chamber and preventing damage to the drive shaft. It is something.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 3A is an overall view of the high-frequency heating device of the present invention with the door opened, and FIG. 3B is a sectional view of a portion of FIG. 3A related to the present invention.

In FIG. 3B, 10 is a high frequency oscillator, and the oscillated microwave passes through a waveguide 11, is supplied to a heating chamber 12, and heats the object 5 to be heated. In this case, there is a method in which the object to be heated 5 is rotated in order to uniformly heat the object, and the rotational force of the drive unit 9 is transmitted to the turntable 1 via the shaft 6. In order to create a fitting portion 3 with the shaft, a portion 2 that is thicker than other portions is required. Further, in order to withstand uneven loads, rollers 7 are arranged on the constricted portion 8 of the bottom surface 4 of the heating chamber. A cover 13 is provided to prevent part of the object to be heated 5 from entering the waveguide during heating. A spatial distance correction diaphragm 14 is provided in the range of the thick portion 2, and a foreign matter inflow prevention diaphragm 15 is provided in the diaphragm 14 concentrically with the shaft 6.

The spatial distance correction aperture 14 is H ₃ from the bottom surface 4 of the heating chamber.
It is set high. The calculation method for H ₃ is as follows.

From FIG. 5, the object to be heated 5 in section A and the bottom surface 4 of the heating chamber
_The apparent distance _{H 1} in the microwave when replaced in _the space _with Thickness h ₂ : Distance between the turntable in section A and the bottom surface of the heating chamber. Apparent distance H ₂ in the microwave when the space between the heated object 5 and the bottom surface 4 of the heating chamber in section B is replaced.
H ₂ = (h ₁ + h ₁ ′) × √ + h ₂ ′ ... h ₁ : Difference in thickness between turntable in section B and turntable in section A h ₂ ′: Turntable in section B and heating before squeezing Distance from the bottom of the refrigerator Since the relative permittivity of the turntable is greater than the relative permittivity of the space, part B is larger than part A by _H3 below. From the formula, H ₃ = H ₂ −H ₁ = h ₁ ′√+h ₂ ′−h ₂ = h ₁ ′√+h ₂ ′−(h ₁ ′+h ₂ ′) = h ₁ ′(√−1) …… In this way, by making the bottom surface of the heating chamber corresponding to the thicker part _H3 higher than the other bottom surfaces, the apparent distance between the object to be heated and the bottom surface of the heating chamber in the microwave is kept constant. This has the effect that uniform heating can be performed.

As an example, the thickness of the turntable is h ₁ = 6 mm, the thick part h ₁ ′ + h ₁ = 12 mm, and the relative permittivity of the turntable space is ε≒4, so from the formula, H ₃ = 6√4−6=6. By narrowing the bottom of the 6mm heating chamber to a height corresponding to the thick part, uniform heating could be achieved.

In addition, by configuring the space correction diaphragm 14 and the foreign matter inflow prevention diaphragm 15 in a circular shape with the shaft 3 as the center as shown in FIG. This has the effect of preventing the turntable from being hit when taking it in and out, or from being damaged by absorbing microwaves.

Another example is the structure shown in FIG. If a thicker part 2 is provided on the circumference than other parts to regulate the position of the roller 7 and to serve as a foot when the turntable 1 is taken out and placed on the cooking table, the thicker part 2 is Correspondingly, by providing the ridges 14 on the bottom surface of the heating chamber, the apparent distance between the object to be heated 5 and the bottom surface 4 of the heating chamber in the microwave is kept close to a constant value, thereby achieving uniform heating. has.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Uniform heating is possible by keeping the apparent spatial distance between the bottom of the heating chamber and the object to be heated in the microwave almost constant using a bulge such as an aperture.

(2) By configuring the protuberances such as apertures in a circular shape around the shaft, it is possible to prevent the turntable from touching the shaft.
Prevents the shaft from being damaged due to the shaft absorbing microwaves.

(3) A restriction is provided around the shaft to prevent foreign matter from entering.
The structure prevents foreign substances such as water and oil from entering the drive unit, which prevents ground faults in the drive unit caused by foreign substances, extending the life of the drive unit, and preventing foreign substances from flowing out of the heating cabinet, preventing the cooking table, This can prevent staining the floor etc.

[Brief explanation of the drawing]

Figures 1a and b are front and side views of a turntable made of dielectric material, Figure 2 is a sectional view of the configuration for driving a conventional turntable, and Figures 3A and B.
4 is an enlarged sectional view of the high-frequency heating device that is an embodiment of the present invention, FIG. 4 is an enlarged sectional view of the present invention of FIG. 3, and FIG. 5 is an enlarged view showing the distance relationship between the object to be heated and the bottom of the heating chamber. FIG. 6 is a cross-sectional view of another embodiment of the present invention. 1... Turntable, 2... Thick part of turntable, 3... Fitting part with shaft, 4...
...Bottom surface of heating chamber, 5...Object to be heated, 6...Shaft, 7...
... Roller, 8 ... Roller arrangement aperture, 9 ... Drive section, 10 ... High frequency oscillator, 11 ... Waveguide,
12... Heating chamber, 13... Cover, 14... Spatial distance correction diaphragm, 15... Foreign matter inflow prevention diaphragm.

Claims (1)

[Scope of Claims] 1. A turntable that is made of a dielectric material and has portions with different wall thicknesses, a shaft that drives the turntable, and a heating chamber that has a bottom surface that supports the shaft; Corresponding to the thick part, when the difference in thickness of the turntable is h and the relative dielectric constant is ε, the aperture height H≒h (√-1)
A high-frequency heating device characterized in that a protuberance having the following properties is provided on the bottom surface of the heating chamber. 2. The high-frequency heating device according to claim 1, wherein the ridge forms the axis within a range of the ridge. 3. The high-frequency heating device according to claim 2, wherein the protrusion has a circular shape centered on the axis.