JPS633435B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a high frequency heating device, such as a microwave oven, that performs heating using radio waves.

Structure of a conventional example and its problems FIG. 1 is a cross-sectional view showing the structure of a conventional high-frequency heating device. In FIG. 1, a heating chamber 1 is provided with a waveguide 2, and this waveguide 2 is provided with a magnetron 3, which is a radio wave oscillation tube. Radio waves from the magnetron 3 are irradiated into the heating chamber 1 through the waveguide 2 to heat the object 4 with high frequency. In order to eliminate uneven heating, the object to be heated 4 is placed on a rotating plate 5 and rotated during heating to ensure uniform heating.

Rotation by induction motor 6 is performed by gear A7 and gear B8.
The deceleration is transmitted to the shaft 9 via the rotary plate 5.
The configuration is such that it can be rotated by being combined with the 10 is a roller that supports the rotating plate 5. The induction motor 6 may be a capacitor motor, a split-phase motor, a corner motor, etc. depending on the starting method, but a corner motor with a simple structure is generally used. Since the induction motor 6 generates a rotating magnetic field by the action of a corner coil or the like, it is of course always started and rotated in a rotational direction determined by the configuration of the motor.

According to such a conventional high-frequency heating device, since the induction motor 6 always rotates in a fixed direction, the gear A7, gear B8, shaft 9, and roller 10 connected thereto also rotate in the same direction, so that the induction motor 6 always rotates in one direction. Force will be added to only. As a result, the side to which force is applied wears out faster than the other side, so-called uneven wear, which is unfavorable in terms of durability.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional drawbacks, and aims to prevent gears, shafts, rollers, etc. from wearing out unevenly, and to realize a highly durable high-frequency heating device.

Structure of the Invention In order to achieve the above object, the high-frequency heating device of the present invention includes a rotary plate drive motor provided with a magnetized rotor and a stator magnetized by a coil, and is activated in either the left or right direction. It is configured as a rotating rotary plate, and the rotation is started in either forward or reverse direction depending on the timing when the power is turned on.

With this configuration, the rotary drive unit rotates either forward or backward depending on the power-on timing, and the ratio of forces applied to gears, shafts, rollers, etc. is equalized, and there is no uneven rotation. This has the effect of realizing a highly durable high-frequency heating device with little wear.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view showing the structure of the high frequency heating device according to the present invention.

In FIG. 2, a heating chamber 11 is provided with a waveguide 12, and this waveguide 12 is provided with a magnetron 13, which is a radio wave oscillator. The radio waves from the magnetron 13 are irradiated into the heating chamber 11 through the waveguide 12, and the object to be heated 14 is heated with high frequency. Heated object 1
4 is placed on a rotating plate 15 to eliminate uneven heating and rotated during heating to ensure uniform heating. 16 is a roller that supports the rotating plate 15, and 17 is a motor that drives the rotating plate 15.

FIG. 3 is a cross-sectional view showing the configuration of the rotating plate drive section of the high-frequency heating device. The rotor 18 is magnetized with multiple poles on its circumference. Pole plates A19 and B20 are similarly arranged alternately on the circumference so as to correspond to the magnetization of the rotor 18, thereby forming a stator. A coil 21 is wound around the outer periphery of the stator. A gear A22 is directly connected to the rotor 18. This gear A22
The gear D26 connected to the shaft 25 is sequentially decelerated through the gear B23 and the gear C24 to rotate the gear D26. The shaft 25 is connected to the rotating plate 15 and thereby drives the rotating plate 15. The rollers 16 support the rotary plate 15 while rolling and function to smoothly rotate the rotary plate 15.

The operation of the above configuration will be explained below.
The magnetic field caused by the coil 21 is generated in the stator, and the pole plate A
19 and the polar plate B20 protrude from above and below, so their polarities are reversed. The polar plates, which are the reversed magnetic poles, are arranged alternately on the circumference. Further, the polarity of the stator becomes an alternating magnetic field depending on the frequency due to the alternating current of the power supply. Repulsion and attraction occur between the magnetic field magnetized in the rotor 18 and the alternating magnetic field on the stator side. Depending on the positional relationship between the rotor 18 and the stator in a stationary state, or the polarity of the polar plates A19 and B20 due to the current phase when the power is turned on, the attraction is first started in the direction in which the attraction is activated, and then the attraction and repulsion are activated. This results in continued rotation in the same direction.

If the static position of the rotor 18 shifts slightly and stops, or if the current phase is reversed when the power is turned on, the attraction and repulsion at the time of turning on will act in the opposite direction, and the engine will start in the opposite direction and continue to reverse. The rotation will continue in the direction. Rotation of the rotor 18 rotates the shaft via gear A22, gear B23, gear C24, and gear D25, and rotates the rotary plate 15. Therefore, depending on the rotation direction of the rotor 18, the rotary plate 15 also depends on the timing when the power is turned on. It will start and rotate in either the forward or reverse direction.

In this way, according to this embodiment, the rotational direction of the motor can be changed randomly, and accordingly, the rotational direction of the rotating plate can also be irregularly selected between the forward and reverse rotational directions. Demonstrate.

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

(1) Since the motor rotates randomly in the forward and reverse directions, the reduction gear, shaft, rotating disc,
Force is not continuously applied to parts such as rollers only in the same direction, but is applied almost equally in both the forward and reverse directions, so uneven wear does not occur. Compared to the conventional configuration, where force is always applied in the same direction and only one side wears out, wear can be reduced by about half, and the service life can be approximately doubled, resulting in a long life. A high-frequency heating device with a long life and high durability can be realized.

(2) If the object to be heated is rotated forward or reverse during heating, it is possible to prevent the object to be heated from shifting inside the container, resulting in more uniform heating.

(3) Some motors are equipped with a reverse prevention cam 27 as shown in Figure 4 on the rotor, and a pawl member 28 is provided integrally with the rotor. Claw reverse prevention cam 2
There is also a configuration in which the rotation stops when it hits point 7, and the repulsion causes it to rotate forward (to the left in the figure). In the case of such a motor, when the rotary plate is forcibly rotated, the claw member 2
If a stronger force is applied to rotate the gear with the pawl 8 fitted in the anti-reverse cam 27, there is a risk that the teeth of the gear will break.

On the other hand, with the configuration according to the present invention, the rotor is not locked, so even if the rotary plate is forcibly rotated from the outside, it will not be destroyed and will be safe. Strong durability.

(4) Compared to a motor with a configuration that forcibly prevents reverse rotation, it not only requires fewer parts, saves resources, and is less expensive, it is also smaller, has a simple structure, is easy to assemble, and is less likely to break down. becomes.

(5) Compared to an induction motor, the structure is simple and the motor itself can be made extremely small; therefore, as shown in the embodiments of the present invention, it is easy to integrate a reduction gear into a structure, and a more compact device can be realized.

(6) Since the motor rotates at a periodic rotation speed, the rotation speed is less affected by fluctuations in the power supply voltage, and stable rotation can always be obtained.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional high-frequency heating device;
The figure is a cross-sectional view of a high-frequency heating device that is an embodiment of the present invention, FIG. 3 is a cross-sectional view showing the structure of the rotary plate drive part of the same device, and FIG. FIG. 3 is a plan view showing a reversal prevention mechanism of the motor. 15... rotating plate, 16... roller, 18... rotor, 19... polar plate A, 20... polar plate B, 21...
... Coil, 22, 23, 24, 26 ... Gear, 2
5... Axis.

Claims (1)

[Claims] 1. A heating chamber, an oscillator that supplies radio waves into the heating chamber, a rotating plate provided in the heating chamber and on which an object to be heated is placed, and a motor that drives the rotating plate, and the motor has a magnetized rotor and A high-frequency heating device is equipped with a stator that is magnetized by a coil, and is configured to start and rotate in either forward or reverse directions.