JPS5941094B2 - High frequency heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency heating device having a mechanism for detecting the temperature of an object to be heated and automatically controlling the heating time.

In a high-frequency heating device such as a microwave oven, a method for automatically controlling the heating by detecting the heating state of the object to be heated is to detect the temperature of the air discharged from the heating chamber or the air inside the heating chamber. Methods of indirectly detecting temperature are being considered.

This is because as the object to be heated is heated, the air in the heating chamber is warmed by the temperature of the hot airflow and steam generated from the object, and this warmed air is discharged from the heating chamber, and this temperature is detected. This technology indirectly detects the temperature of the object to be heated and controls the heating time. There are good foods, and there are foods such as potatoes that need to be heated to about 90 to 100°C and then heated for a certain amount of time to gelatinize the starch and soften the structure.

In this case, with the method of detecting the temperature of the air discharged from the heating chamber or the air inside the heating chamber, when steam starts to be generated from the object to be heated, the temperature of the air discharged from the heating chamber rises rapidly, and eventually reaches thermal equilibrium. Once the temperature has reached the saturated state, the temperature will not rise any further, so it is only necessary to raise the temperature as described above.Items to be heated can be brought to a temperature that is almost ready to eat. For heated objects, it is necessary to heat them using the above-mentioned method plus a timer device.

By the way, in the case of a method of detecting the temperature of the air discharged from the heating chamber or the air inside the heating chamber, from the viewpoint of detection accuracy, it is not preferable to introduce hot air into the heating chamber after cooling the high frequency generator or the like.

However, if heating continues while generating a large amount of steam from the object to be heated without introducing hot air as described above, the steam will not be sufficiently carried out of the heating chamber and will remain inside the heating chamber.
A part of the finder of the door becomes cloudy, making it impossible to observe the heating status of the heated object inside the heating chamber from the outside, or causing a large amount of water to accumulate inside the heating chamber.

However, when trying to control the heating time by detecting the temperature of the air discharged from the heating chamber or the air inside the heating chamber, in most cases a large amount of steam is generated. By the way, since the heating is stopped, the arrangement using steam is not so much of a problem.

However, what this invention is trying to address is
After reaching a predetermined temperature, the above-mentioned arrangement appears when it is desired to continue heating for a necessary time using a timer.

An object of the present invention is to provide a high-frequency heating device that can be used comfortably and eliminates the above-mentioned drawbacks of the prior art, and does not cause deterioration in detection accuracy and does not cause clouding of a portion of the finder of the door.

In order to achieve the above object, the present invention includes a temperature detection mechanism that detects the temperature of ventilation air in a heating chamber, an automatic heating time control mechanism that is activated by the temperature detection mechanism, and a timer device that manually sets the heating time. , an air path switching device for switching the air path for ventilation of the heating chamber in response to the operation of the automatic control mechanism and the timer device, manual means for operating the air path switching device, and automatic means; This allows automatic and manual switching from the control mechanism to the timer device together with the air path switching device.

The present invention will be explained below along with examples.

FIGS. 1, 2, 3 and 4 show an embodiment of a high frequency heating device according to the present invention.

Figure 2 is a cross-sectional plan view of Figure 1, showing the flow of air when an automatic control mechanism is used, and Figure 3 is a cross-sectional view of Figure 1, showing the flow of air when using a timer device. It shows the flow of

Further, FIG. 4 shows the flow of air when automatically switching from the automatic control mechanism to the timer device.

The arrows in FIG. 1, FIG. 2, FIG. 3, and FIG. 4 indicate the direction of the wind flow, and the solid line arrow indicates the case where a force phase motion control mechanism is used, and the broken line arrow indicates the case where a timer device is used.

In Fig. 1, 8 is an air path switching device, 9 is a heating chamber exhaust port,
Reference numeral 5 designates an air path blocking device, and 18 represents an air path switching device and a control switching device that can be operated from the outside in conjunction with the air path blocking device.

The air path switching device 8 includes a high-frequency generator cooling air exhaust duct 8c and a shaft 8 inside the high-frequency generator cooling air exhaust duct 8c shown in FIGS. 2, 3, and 4.
The damper 8a is movable around the damper 8a.

Further, the air passage blocking device is constituted by a heating chamber exhaust duct 5c and a damper 5a that is movable around a shaft 5b inside the heating chamber exhaust duct 5c.

FIG. 2 is a plan cross-sectional view of FIG. 1, showing the positions of the damper 8a and the damper 5a when the externally operable control switching device 18 is replaced by the automatic control mechanism 13.

To explain the flow of wind when using only the automatic control mechanism, the high frequency generator 6 oscillates microwaves, and the object to be heated 2 is heated.

The blower 7 rotates and exhausts the air inside the heating chamber 1 from the heating chamber exhaust port 9.

The outside air that enters the heating chamber 1 from the heating chamber intake port/heating chamber exhaust port 15 passes around the object to be heated 2 and then enters the heating chamber exhaust port 9.
The air flows out of the heating chamber, and flows out of the high-frequency heating device through the high-frequency generator cooling air exhaust port 10 while cooling the high-frequency generator 6 through the blower 7 from the heating chamber exhaust duct 5c.

On the other hand, outside air enters the machine room 17 through the machine room intake port 17a formed by drilling a group of small holes in the bottom of the high-frequency heating device, and is sucked into the blower 7 while cooling the electrical components.
The air passes through the high-frequency generator 6 together with the discharged air, and flows out of the high-frequency generator through the high-frequency generator cooling air outlet 10.

At this time, since the temperature detection mechanism 4 is provided in the air path cutoff device 5, it detects the temperature change of the air discharged from the heating chamber 1 through the heating chamber exhaust port 9, thereby detecting the temperature of the heated object. 2 temperature can be detected indirectly.

Then, when this detection signal is applied to the automatic control mechanism 13,
When the rise in exhaust gas temperature reaches a preset value, the automatic control mechanism 13 stops the oscillation of the high frequency generator 6 and ends the heating.

Next, the air passage when used in the timer device 14 will be explained using FIG. 3.

In use, the damper 8a and the damper 5a are kept in the state shown in FIG. 3 using a control switching device 18 which is a manual means and can be operated from the outside.

As a result, the blower 7 operates during the heating period, and the outside air that enters the machine room 17 from the machine room intake port 17a passes through the air path switching device 8 while cooling the electrical components in the machine room, and passes through the heating room intake port 16. and enters the upper part of the partition plate 11 inside the heating chamber 1.

Thereafter, this wind is blown onto a part of the finder of the door 3 through the partition plate hole 11a, passes around the object to be heated 2 while preventing steam condensation on the finder, and passes through the heating chamber intake port and heating chamber exhaust port 15. , leaks out of the high-frequency heating device.

That is, when used with the automatic control mechanism 13, hot air such as cooling air from the high frequency device 6 is not introduced into the heating chamber 1 from the viewpoint of temperature detection accuracy, and when used with the timer device 14, the finder of the door 3 is The structure is such that warm air is introduced into the heating chamber 1 in order to prevent fogging.

Next, the flow of air when the temperature of the object 2 to be heated is raised using the automatic control mechanism 13 and then heating is performed using the timer device 14 will be explained using FIG. 4.

In use in FIG. 4, the damper 8 is operated by using an externally operable control switching device 18 which is a manual means.
8 and the damper 5a are kept in the solid line state, and at the same time, the timer device is also set to a desired time.

When the power supply device 12 is turned on, heating begins, and the flow of air becomes as shown by the solid line.

The temperature of the heated object 2 rises to the set temperature and the automatic control mechanism 1
3 operates, the electromagnetic device 19 operates and the damper 8a and the damper 58 automatically move from the solid line state to the broken line state, changing the flow of air from the solid line state to the broken line state.

At the same time, the timer device 14 starts operating and turns off the power after heating for the set time.

The mechanism for automatically controlling the heating time of the object to be heated 2 has been described above, but the features of the present invention are as shown in FIGS.
As shown in FIG.
It is possible to manually switch between them, and to automatically switch from the automatic control mechanism to the timer device 14 using the electromagnetic device 19.

The temperature of the heated object 2 is automatically detected using the automatic control mechanism 13, and when the set temperature is reached, the electromagnetic device 19 is operated to automatically switch the damper 88 and the damper 5a, and the door 3 is closed.
blow warm air onto a part of the finder of the timer device 14.
are activated at the same time and continue heating for a set time, so even if heating continues while generating a large amount of steam from the object to be heated 2, part of the viewfinder of the door 3 may become cloudy with steam and the inside of the heating chamber 1 may be leaked from the outside. Inconveniences such as not being able to observe the heating condition of the heated object 2 or the inside of the heating chamber 1 being covered with water droplets due to a large amount of steam are eliminated.

In the above explanation, the timer device 14 has been explained as being a manual type, but the present invention is also applicable to a method in which a time that applies to the majority of the objects to be heated 2 is automatically set in advance.

Furthermore, when it is desired to use only the automatic control mechanism 13 or only the timer device 14, by manually moving the control switching device 18, the ventilation air in the heating chamber can be appropriately used.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing one embodiment of the present invention, and FIG. 2 is a perspective view showing one embodiment of the present invention.
Figure 3 is a cross-sectional plan view of the automatic control mechanism, showing the air path of the automatic control mechanism; Figure 3 is a cross-sectional plan view of Figure 1, showing the air path for a timer device; Figure 4 is a cross-sectional plan view of Figure 1. FIG. 3 is a diagram showing an air path in the case of automatic switching from an automatic control mechanism to a timer device. In the figure, 1... Heating chamber, 2... Heated object, 4... Temperature detection mechanism, 8...
Air path switching device, 13...Sound control mechanism, 14...
・Timer device.

Claims (1)

[Claims] 1. In a high-frequency heating device that heats an object by supplying high-frequency power into a heating chamber that stores an object to be heated, a temperature detection mechanism that detects the temperature of ventilation air in the heating chamber, and a temperature detection mechanism that operates by the temperature detection mechanism. an automatic control mechanism, a timer device for manually controlling the heating time, and in response to the operation of the automatic control mechanism and timer device, when using the automatic control mechanism, hot air is introduced into the heating chamber after cooling the high frequency generator. On the other hand, when using the timer device, there is an air path switching device that switches the air path for ventilating the heating chamber so that warm air after cooling the high frequency generator enters the heating chamber, and this air path switching device. A high-frequency heating device characterized by comprising an automatic switching means for switching from a state when using an automatic control device to a state when using a timer device, and a manual switching means for manually operating an air path switching device.