JP2558442Y2 - Microwave heating equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave heating apparatus for heating an object to be heated using microwaves, and more particularly to a microwave heating apparatus suitable for preventing uneven heating.

[0002]

2. Description of the Related Art Conventionally, there has been provided a microwave heating apparatus (microwave oven) in which microwaves are introduced into a heating chamber to heat an object to be heated such as food. As methods for achieving uniform heating in this microwave heating apparatus, there are a turntable rotation method in which a turntable on which an object to be heated is mounted is rotated, and an antenna rotation method in which an antenna that radiates microwaves into a heating chamber is rotated.

In the turntable rotating method, if the object to be heated placed on the turntable is too large, the object to be heated hits the inner wall of the heating chamber and the rotation of the turntable is hindered. Can not
There was a drawback that uniform heating could not be performed. Therefore, the rotation axis where both the turntable and the antenna are arranged coaxially, the upper position where the drivetable is connected to the turntable side,
There has been provided a microwave heating apparatus provided with a coil spring for vertically moving the rotary shaft to an upper position side, while being provided vertically movable between a lower position drivingly connected to the antenna side.

In this microwave heating apparatus, a turntable rotating system is usually used. When the object to be heated is large as described above, the antenna is replaced by a special turntable and the rotating shaft is pushed down to a lower position. The system is switched to the system.

[0005]

However, this microwave heating apparatus has a problem in that the turntable must be replaced when switching between the above two methods, which is troublesome. Therefore, an object of the present invention is to provide a microwave heating apparatus capable of automatically performing the switching between the above two methods without replacing a turntable.

[0006]

In order to achieve the above object, a microwave heating apparatus according to the present invention is provided with a turntable which is placed in a heating chamber and is rotated while placing an object to be heated, A microwave heating device comprising: a power supply unit that supplies microwaves from an antenna that is rotated between the antenna and a bottom of the heating chamber; and a rotation shaft that is drivingly connected to one of the turntable and the antenna. An optical sensor that detects that the object to be heated placed outside the turntable is more than a predetermined amount outward in the radial direction of the turntable, and based on a signal from the optical sensor, rotates when the above-mentioned protrusion is detected. Drive connection switching means for drivingly connecting the shaft to the antenna side and drivingly connecting the rotary shaft to the turntable side when the protrusion is not detected. It is intended to.

[0007]

According to the structure of the present invention, when the object to be heated placed on the turntable protrudes beyond the turntable in the radial direction by a predetermined amount or more, the protrusion is detected by the optical sensor. Drive connection switching means drives and connects the rotation shaft to the antenna based on the detection signal.
Thus, when there is a possibility that the rotation of the turntable may be suppressed, the antenna system is automatically switched to the antenna system.

When the object to be heated is small and the protrusion is not detected, the rotating shaft is drive-connected to the turntable by the drive connection means. As a result, in a normal case where the rotation of the turntable is not suppressed, the system is automatically switched to the turntable rotation method.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 3 is an overall schematic perspective view of the microwave heating apparatus according to one embodiment of the present invention, showing a state in which a turntable for mounting an object to be heated is removed. FIG.
Referring to FIG. 1, a heating chamber 2 for heating an object to be heated made of food is provided inside a main body 1, and a door 3 for opening and closing the heating chamber 2 is provided at a lower portion of a front surface of the main body 1. Installed.

Referring to FIG. 1 showing a vertical cross section of the bottom of the heating chamber 2, a turntable 13 on which an object 19 to be heated is mounted and rotated is disposed at the bottom of the heating chamber 2. Between the turntable 13 and the bottom plate 2a of the heating chamber 2,
A rod-shaped antenna 7 that emits microwaves and rotates in a horizontal plane is disposed in the heating chamber 2 (see FIGS. 1 and 3).

With the lower surface near the edge of the turntable 13 supported on the bottom plate 2a of the heating chamber 2, the turntable 1
A roller 14 that rotates with the rotation of the roller 3 is provided. The antenna 7, a vertical cylindrical shaft 6 serving as a rotation center of the antenna 7, and a bearing 15 disposed on the cylindrical shaft 6 and rotatably supporting a rotating shaft 9 described later are integrally connected,
The antenna unit 5 is configured. The cylinder shaft 6 is
The microwave oscillated by the microwave oscillator is inserted into a waveguide 4 for guiding the microwave below the heating chamber 2. Feeding means is constituted by the waveguide 4 and the antenna unit 7.

The upper part of the waveguide 4 is constituted by the bottom plate 2 a of the heating chamber 2. The upper portion of the cylindrical shaft 6 is rotatably supported by a sealing plate 8 that closes the opening of the bottom plate 2a of the heating chamber 2. A rotary shaft 9 for driving the turntable 13 and the antenna 7 is disposed with the cylindrical shaft 6 penetrating coaxially. The rotation shaft 9 is made of a dielectric material. The lower end of the rotating shaft 9 is coaxially fixed to a pulley 10 that is rotationally driven via a belt 11 by a motor. The pulley 10 is made of a ferromagnetic material,
A plunger of the electromagnet 23 described later is also used. The lower end of the rotating shaft 9 is rotatably supported by a bearing 16 provided below the waveguide 4. Note that this bearing 16
Also function as a thrust bearing for the cylindrical shaft 6 of the antenna unit 5. The upper end side of the rotating shaft 9 is rotatably supported by the bearing 15 of the antenna unit 5.

At the upper end of the rotating shaft 9, a concave portion 13a provided on the lower surface of the center of the turntable 13 as shown in FIG.
And a turntable connecting projection 9a for drivingly connecting the turntable 13 by fitting into the boss. Also,
Slightly below the turntable connection protrusion 9a, an antenna connection protrusion 9b that fits into a concave groove 18 provided on the upper surface of the bearing 15 of the antenna unit 5 to drive and connect the antenna unit 5 as shown in FIG. Is formed. The rotating shaft 9 is driven and connected to the turntable 13 when it is moved upward, and is driven and connected to the antenna 7 when it is moved downward. The rotating shaft 9 is urged upward by a coil spring (not shown) to be drivingly connected to the turntable 13 (see FIG. 2).

An optical sensor 21 is mounted on the bottom plate 2a in the heating chamber 2 radially outward of the turntable 13. The optical sensor 21 is a light receiving sensor that receives light from a lighting lamp (not shown) in the heating chamber 2, and the object to be heated placed on the turntable 13 cannot be rotated by the turntable 13. It is detected based on the amount of received light that the turntable 13 protrudes radially outward.

The optical sensor 21 is connected to an amplifier 22. The amplifier 22 outputs the output signal of the optical sensor 21 to the electromagnet 2
By rotating the pulley 10 as a plunger of the electromagnet 23 against the coil spring, the rotary shaft 9 is lowered to be driven and connected to the antenna 5. The rotary shaft 9 is turned to the turntable 13 side and the antenna 7 by the coil spring, the amplifier 22, the electromagnet 23, and the pulley 10 for urging the rotary shaft 9 upward.
A drive connection switching means A for selectively driving and connecting to the side is provided.

According to this embodiment, the turntable 13
If the object to be heated 19 placed on the outside of the turntable 13 protrudes outward in the radial direction of the turntable 13, the protrusion is detected by the optical sensor 21, and based on this detection signal,
Drive connection switching means A drives and connects the rotating shaft 9 to the antenna 7 side. Thereby, when there is a possibility that the object to be heated 19 cannot rotate in the heating chamber 2, it is possible to automatically switch to the antenna system. Further, in a normal case where the object to be heated 19 is small and the turntable 13 can be rotated, the protrusion is not detected, so that the drive connecting means A
The rotation shaft 9 is turned by the coil spring
Side, and can be automatically switched to the turntable rotation system.

As described above, the drive connection switching means A depends on the degree of protrusion of the object to be heated 19 from the turntable 13.
However, since it is selectively switched to the drive connection to the turntable 13 side or the antenna 7 side, both types of switching can be automatically performed without replacing the turntable 13 as in the related art. Therefore, uniform heating can be performed without the troublesome work of replacing the turntable, which is convenient.

The present invention is not limited to the above embodiment. For example, a spring clutch or other known clutch mechanism may be used as the drive connection switching means.
Various design changes can be made without changing the gist of the present invention.

[0019]

As described above, according to the microwave heating apparatus of the present invention, the drive connection switching means selects the drive connection to the turntable side or the antenna side according to the degree of protrusion of the object to be heated from the turntable. The switching between the two methods can be performed automatically without replacing the turntable as in the related art.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a microwave heating apparatus according to an embodiment of the present invention, showing a state where a turntable cannot be rotated.

FIG. 2 is a longitudinal sectional view of a main part of the microwave heating device, showing a state in which a turntable can be rotated.

FIG. 3 is a perspective view showing the entire configuration of the microwave heating device.

[Explanation of symbols]

 2 Heating chamber 7 Antenna 9 Rotation axis 13 Turntable 19 Heated object 21 Optical sensor A Drive connection switching means B Power supply means

Claims (1)

(57) [Scope of request for utility model registration] 1. A turntable disposed in a heating chamber and rotated by placing an object to be heated, and a power supply means for supplying microwaves from an antenna rotated between the turntable and the bottom of the heating chamber. , A microwave heating device having a rotary shaft that is drivingly connected to one of a turntable and an antenna, wherein an object to be heated placed on the turntable protrudes beyond a predetermined amount radially outward of the turntable. An optical sensor for detecting that the protrusion is detected, based on a signal from the optical sensor, when the protrusion is detected, the rotating shaft is drivingly connected to the antenna side, and when the protrusion is not detected, the rotation shaft is connected to the turntable side. And a drive connection switching means for driving connection with the microwave heating device.