JPS5919201Y2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a high-frequency heating device equipped with a steam generator.

In general, this type of high-frequency heating device, such as a microwave oven, is capable of not only microwave cooking using high frequency waves, but also steam cooking using steam, and there are devices that can handle other types of cooking. .

However, steam cooking is characterized by a long cooking time, which not only impairs the speed cooking function of the microwave oven, but also causes the problem that a large amount of water adheres to the walls of the cooking chamber.

This idea was made in view of the above circumstances,
The purpose of this is to shorten the steam heating operation time without impairing the essence of the steam heating operation, and thereby to reduce the amount of water that adheres to the inside of the heating chamber. The present invention provides a high frequency heating device.

An embodiment of this invention will be described below with reference to the drawings.

In FIGS. 1, 2, and 3, reference numeral 1 denotes a main body of a microwave oven, on the front of which a door 2 is pivotally supported and an operation panel 3 is provided.

A heating chamber, that is, a cooking chamber 4 is provided in the main body 1 corresponding to the door 2, and a rotating shelf 5 for placing food to be cooked is provided in the cooking chamber 4.

The shelf board 5 is connected to a motor 6 provided outside the cooking chamber 4, and is rotationally driven by the motor 6.

Furthermore, a high frequency generator such as a magnetron 7 is installed on the back side of the ceiling of the cooking chamber 4. magnetron 7
The antenna 7□ is led out into the cooking chamber 4.

Therefore, the high frequency waves emitted from the magnetron 7 are supplied into the cooking chamber 4, and the high frequency waves are agitated by the stirrer fan 8 provided on the ceiling of the cooking chamber 4.

Further, one end of a steam pipe 9 communicating with the inside of the cooking chamber 4 is connected to the upper part of one side of the cooking chamber 4, and the other end of this steam pipe 9 is connected to a steam generator 10.

This steam generator 10 includes a steam tank 11° to which the other end of the steam pipe 9 is communicated.
The water supply tank 14 supplies water to the steam tank 11 through a water supply pipe 13 and a heater 12 provided therein.

Therefore, steam is generated in the steam tank 11 as the heater 12 operates, and is supplied into the cooking chamber 4 via the steam pipe 9.

A thermal switch mounting plate 15 is welded and fixed to one end of the steam pipe 9, and a thermal switch 17 is mounted on the mounting plate 15 by a fixing frame 16.

In this way, the temperature of the steam passing through the steam pipe 9 changes to the mounting plate 1.
5 to the thermal switch 17.

In this case, the thermal switch 17 is configured to operate when the temperature of the steam passing through the steam pipe 9 reaches a predetermined value, for example, around 110° C., that is, when the steam generation state becomes stable.

FIG. 4 shows the control circuit.

One end of the AC power source 20 is connected to one end of a cooking switch (normally open automatic return contact) 23 via a power switch 21 and a door switch 22 in series.

The other end of this cooking switch 23 is connected to one end of a timer 24 via a timer switch 24□, and the other end of this timer 24 is connected to the other end of the power source 20.

Further, a relay 25 is connected in parallel to the timer 24, and a normally open contact 25a1 of this relay 25 is connected in parallel to the cooking switch 23.

Further, the motor 6 is connected to the relay 25 in parallel.

One end of a relay 27 is connected to one end of this motor 6 via a steam cooking setting switch 26, and the other end of this relay 27 is connected to the other end of the motor 6.

The switch 26 is provided on the operation panel 3, and when turned on, steam cooking can be set.

Further, one end of the thermal switch (normally closed contact) 17 is connected to one end of the motor 6 via a steam-microwave cooking setting switch 28.
The other end is connected to one end of the relay 27 mentioned above.

The switch 28 is provided on the operation panel 3, and when turned on, steam-microwave cooking can be set.

Furthermore, the thermal switch 17 includes a switch 29.
are connected in parallel.

This switch 29 receives the rotation of the motor 6 by a cam mechanism (not shown) or the like, and is turned on and off at predetermined time intervals.

On the other hand, one end of the heater 12 is connected to a connection point between the power switch 21 and the door switch 22 through a normally open contact 25a2 of the relay 25 and a normally open contact 27a of the relay 27 in series, The other end of the heater 12 is connected to the other end of the power source 20 via the normally open contact 25a3 of the relay 25.

Furthermore, a primary winding 30. One end of the primary winding 30□ is connected, and the other end of the primary winding 30□ is connected to the heater 12.
connected to the other end.

A secondary winding 302 in the transformer 30 is connected between the anode and cathode of the magnetron 7 via a rectifier circuit consisting of a capacitor C and a diode D.

In the magnetron 7, the anode is grounded, and the heater is connected to the secondary winding 303 of the transformer 30.

Next, the operation in the above configuration will be explained.

First, the power switch 21 is turned on, the food to be cooked is placed on the shelf board 5 in the cooking chamber 4, and the door 2 is closed.

When performing microwave cooking, the timer 24 is used to set the time required for microwave cooking.

In this way, when preparation for microwave cooking is completed, the cooking switch 23 is turned on.

Then, the timer 24, relay 25, and motor 6 are connected to the power source 20, and the magnetron 7 is operated by closing the contacts 25a2 and 25a3 based on the operation of the relay 25.

That is, high frequency waves are supplied into the cooking chamber 4, and microwave cooking is performed.

After that, when the time preset by the timer 24 has elapsed, the timer switch 24□ is opened and the timer 24 is activated.
, the relay 25 and the motor 6 are disconnected from the power supply 20,
Among these, contacts 25a2, 2 based on the stop of operation of relay 25
The operation of the magnetron 7 is stopped by the return of 5a3.

In other words, microwave cooking is finished.

Further, when steam cooking is to be performed, the switch 26 is turned on to set the steam cooking, and the timer 24 is set for the time required for the steam cooking.

When the preparation for steam cooking is thus completed, the cooking switch 23 is turned on.

Then, the timer 24, relay 25, motor 6, and relay 27 are connected to the power supply 20, and among these, contacts 25 az and 25 a3 are closed based on the operation of the relay 25, and contact 27 b is opened based on the operation of the relay 27. and contact point 27
The heater 12 is operated by closing of a.

That is, the water in the steam tank 11 is heated, and the steam generated in the steam tank 11 is thereby supplied into the cooking chamber 4 via the steam pipe 9.

In this way, steam cooking is performed.

After that, when the time preset by the timer 24 has elapsed, the relay 25 stops operating and the contacts 25 a2, 2
5 The operation of the heater 12 is stopped by the return of a3.

In other words, the steam cooking ends.

By the way, as mentioned above, this type of steam cooking is characterized by a long cooking time, which makes the cooking chamber 4
There was a problem with a large amount of water adhering to the interior walls.

Therefore, when carrying out this steam cooking, the switch 28 is turned on without turning on the switch 26.

That is, steam-microwave cooking is set.

Then, the optimum time for steam-microwave cooking is set using the timer 24, and the cooking switch 23 is turned on.

Then, timer 249, relay 25, motor 6, and relay 27 are connected to power supply 20, and among them, relay 25.
The heater 12 operates based on the operation of 27.

That is, the water in the steam tank 11 is heated, and steam is gradually supplied into the cooking chamber 4.

Thus, the temperature of the steam passing through the steam pipe 9 gradually rises, and when the temperature reaches around 110° C., that is, when the steam generation state becomes stable, the thermal switch 17 opens.

Then, the switch 29, which has already been turned on and off based on the operation of the motor 6, causes the relay 27 to perform an adiabatic operation.

Therefore, the heater 12 and the magnetron 7 are operated alternately by the contacts 27b and 27a, and steam and high frequency waves are alternately supplied into the cooking chamber 4.

That is, steam-microwave cooking is performed.

In this case, the ratio of the time period for supplying steam to the inside of the cooking chamber 4 and the time period for supplying high-frequency waves is set so as not to impair the essence of cooking using steam.

In this way, the cooking time for steam cooking is shortened as a result, and the amount of water adhering to the walls in the cooking chamber 4 is also reduced.

After that, when the time preset by the timer 24 has elapsed, the relay 25 stops operating and the contact 25a2,
25a3, the operation of the heater 12 is stopped.

In other words, the steam-microwave cooking ends.

In such steam-microwave cooking, the steam generation device is operated continuously so that the steam generation state is stable at the start, but this takes into account the preheating time for the water in the steam tank 11. It is a thing,
This makes it possible to prevent simple intermittent high-frequency cooking at the start of cooking.

In other words, this eliminates the disadvantages of alternating between steam and high frequency to shorten the steam cooking time.

In the above embodiment, the switch for alternately operating the heater 12 and the magnetron 7 is not limited to the motor 6, but if other means such as a so-called defrosting timer is provided, the switch may be turned on or off in conjunction with the timer. It may be turned off.

Furthermore, the same effect can be obtained even if the thermal switch 17 is directly attached to the steam pipe 9 using the fixing frame 50 as shown in FIGS. 5a and 5l).

In addition, this invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without changing the gist of the invention.

As described above, according to this invention, with the above-described configuration, the steam generator and the high-frequency heating device are operated alternately, and at the start of this alternate operation, the steam generator is continuously operated until the steam generation state is stabilized. This makes it possible to shorten the steam heating operation time without sacrificing the essence of the steam heating operation, which is highly practical as it also reduces water adhering to the heating chamber. A high-frequency heating device can be provided.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention; Fig. 1 is an external perspective view, Fig. 2 is a schematic diagram of the internal mechanism, and Fig. 3 is a schematic diagram of the internal mechanism.
Figures a and b are front and side views showing details of the thermal switch mounting part in Figure 2, Figure 4 is the configuration of the control circuit, and Figure 5 a and l) are modifications of the thermal switch mounting part. FIG. 3 is a front view and a side view showing details. 1... Body, 4... Heating chamber (cooking chamber)
, 7...High frequency generator (magnetron), 1
0... Steam generator, 12... Heater, 17... Thermal switch, 29...
·switch.

Claims (1)

[Scope of utility model registration request] A heating chamber, a high-frequency generator that supplies high-frequency waves into the heating chamber, a steam generator that supplies steam into the heating chamber via a steam pipe, and the steam generator and the high-frequency generator are operated alternately. a switch, and a thermal switch that is attached to the steam pipe and operates the steam generator continuously regardless of the operation of the switch until the temperature of the steam passing through the steam pipe reaches a predetermined value at the start of heating operation. A high frequency heating device characterized by: