JPS6025694B2 - 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 high-frequency heating devices such as microwave ovens, this method detects the heating state of the object to be heated and automatically controls the heating.
A method has been considered in which the temperature of the object to be heated is indirectly detected by detecting the air discharged from the heating chamber or the temperature of the air inside the heating chamber.

FIG. 1 shows a conventional example of a high frequency heating device using the above method.

The arrows in Figure 1 indicate the direction of the wind flow. Now, when the control circuit is set so that the control switching device 18 can also be used by the automatic control mechanism 13, the power supply device 12 operates, the high frequency generator 6 oscillates, and the heating chamber 1 is supplied with high frequency power to be heated. Heating object 2 is heated.

In addition, the high-frequency generator cooling blower 7 operates, and as a result, the outside air entering the heating chamber intake □8 enters the heating chamber 1, passes around the object to be heated 2, and exits the heating chamber exhaust port 9 into the heating chamber 1.
The air flows out to the outside, passes through the blower 7 to cool the high-frequency generator 6, and flows out from the high-frequency generator cooling air outlet 10. 1), the temperature of the outside air entering the heating chamber 1 is detected by the intake temperature detection mechanism 5, and the temperature of the air exhausted from the heating chamber 1 is detected by the temperature detection mechanism 4, as shown in FIG. As shown in , the intake air (i.e., outside air) temperature remains constant, but the exhaust temperature increases linearly with heating time. Incidentally, this increase in exhaust temperature is caused by the object to be heated 2 warming the air in the heating chamber 1 as the object to be heated 2 is heated by the high frequency power generated by the high frequency generator 6.

This situation is clearer in Figure 3. FIG. 3 shows the relationship between the temperature of the object to be heated 2 heated by the high frequency power generated by the high frequency generator 6 and the temperature of the air discharged from the heating chamber 1. According to FIG. 3, when the temperature of the object to be heated 2 is relatively low, the temperature of the object to be heated 2 and the temperature of the air discharged from the heating chamber exhaust port 9 are approximately proportional to each other, and the temperature of the object to be heated 2 is This shows a situation in which the exhaust temperature suddenly begins to rise when the temperature approaches the saturation temperature. Therefore,
By knowing this property well and detecting the rise in exhaust gas temperature during heating, it is possible to detect the state of heating of the object to be heated 2 and to control the oscillation of the high frequency generator 6 by the automatic control device 13. Next, when the control switching device 18 is switched so that it can be used with the manual control mechanism 14, the flow of ventilation air in the heating chamber 1 is the same as when using the automatic control mechanism, but the heating time is The object to be heated 2 is heated for a period of time set by a manual control mechanism such as a timer, regardless of the temperature of the object.

However, in the conventional system as shown in FIG. 1, it is difficult to introduce warm air such as cooling air from a high-frequency generator into the heating chamber from the viewpoint of improving detection accuracy.

The oscillation of the high-frequency generator 6 generates heat, and the temperature of the high-frequency generator 6 increases as time passes after the start of oscillation. Moreover, this temperature rise is not uniform depending on the temperature of the high frequency generator 6 at the time of starting oscillation, the type and amount of the heated object 2, etc. When such hot air that changes over time and whose temperature rise is not uniform is introduced into the heating chamber 1, the temperature of the exhaust gas from the heating chamber 1 increases due to the heating of the heated object 2, and the temperature of the high frequency generator 6 increases. It is difficult to distinguish this from the temperature rise of the exhaust gas from the heating chamber 1 due to warm air such as cooling air. For this reason, the automatic control mechanism 13
When the temperature of the heated object 2 reaches a preset value, the oscillation of the high-frequency generator 6 is automatically stopped, so there is no problem. When using the manual control mechanism 14 such as a timer for heating the object 2 until it becomes soft even after the temperature of the object 2 reaches a preset value, a large amount of water vapor is generated from the object 2 to be heated. As the heating continues, water droplets condense on the wall of the heating chamber 1 and water eventually accumulates inside the heating chamber.Furthermore, in a high-frequency heating device with a finder installed in the door 3, the finder becomes cloudy due to condensation of water vapor. This has the disadvantage that the heated state of the object to be heated 2 cannot be seen. Furthermore, as shown in Figure 1, the outside air from the high-frequency heating device is directly fed into the heating chamber 1 and the finder of the door 3).
Even if it is sprayed, the above problem cannot be solved because the temperature difference between the outside air temperature and the water vapor temperature is large. An object of the present invention is to eliminate the drawbacks of the above-mentioned secondary system in a high-frequency heating device that is equipped with the automatic control mechanism 13 and the manual control mechanism 14, and to provide a comfortable system without condensation on the walls of the heating chamber or the finder of the door. An object of the present invention is to provide a usable high-frequency heating device. In order to achieve the above object, the present invention provides a high-frequency heating device that supplies high-frequency power into a heating chamber 1 that houses an object to be heated 2 to heat the object to be heated. It is equipped with a temperature detection mechanism 4 to detect the temperature, an automatic control mechanism 13 for high frequency output operated by the temperature detection mechanism, and a manual control mechanism 14 for heating time, which corresponds to the operation of the automatic control mechanism 13 and the manual control mechanism 14. The heating chamber is equipped with an air passage switching device 17 that switches the air passage for ventilation of the heating chamber, and the control circuits of the automatic control mechanism 13 and the manual control mechanism 14 are switched in conjunction with the operation of the air passage switching device 17. That is. The present invention will be explained below with reference to Examples. FIG. 4, FIG. 5, and FIG. 6 show an embodiment of the high-frequency heating device according to the present invention.

In FIG. 4, 17 is an air path switching device, 15 is a heating chamber inlet and heating chamber exhaust port, and 18 is a control sliding device which can be operated from the outside in conjunction with the air path sliding device. Air passage cutting sliding device 17
The high-frequency generator cooling air exhaust duct 17c shown in FIGS. 5 and 6 is comprised of a damper 17a that is movable around a shaft 17b inside the duct 17c. FIG. 5 is a plan sectional view of FIG. 4, and shows the position of the damper 17a when the control switching device 18 is changed to the automatic control mechanism 13. FIG. 6 is a plan sectional view of FIG. 4, showing the damper 17 when the control sliding device is used as the manual control mechanism 14.
It shows the position of a. The arrows in Figures 4, 5, and 6 indicate the direction of the wind; solid arrows indicate the direction of the wind when used with an automatic control mechanism, and dashed arrows indicate the direction of the wind when used with a manual control mechanism. be. In Figure 4, heating chamber 1
The heated object 2 placed inside is supplied with V from the high frequency generator 6.
It is heated by the supplied high frequency power. During this heating period, the blower 7 operates, and when used with the automatic control mechanism 13, the outside air that enters the heating chamber 1 from the heating chamber inlet and heating chamber exhaust port 15 passes around the object to be heated 2. It flows out of the heating chamber 1 from the heating chamber exhaust port 9, and passes through the high-frequency generator cooling air exhaust duct 17c while cooling the high-frequency generator 6 through the air blower 7 from the heating chamber exhaust duct 16 to exhaust the high-frequency generator cooling air. It flows out of the high-frequency heating device through the opening 10. On the other hand, outside air enters the machine room 21 from the machine room intake port 21a, which is formed by drilling a small hole in the bottom of the high-frequency heating device, and is sucked into the blower 7 while cooling the electrical components. High frequency generator 6 along with the discharged air
It flows out of the high-frequency heating device through the high-frequency generator cooling storm exhaust low 0. (Solid line arrow in the figure) The damper 17a for the air passage sliding door in this case is in the state shown in FIG. In FIG. 5, the temperature of the air taken into the heating chamber 1 is detected by the intake temperature detection mechanism 5, and the temperature of the air taken into the heating chamber 1 is detected by the heating chamber exhaust port 9.
When the temperature of the air discharged from the heating chamber 1 is detected by the temperature detection mechanism 4, the temperature of the object to be heated 2 can be indirectly detected as described above. 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 is activated to stop the oscillation of the high frequency generator 6 and end the heating. Next, the air passage when used in the manual control mechanism 14 such as a timer will be explained using FIG. 6. When the control switching device 18 is operated during use, the air path switching device 17
The inner damper 17a changes from the state shown in FIG. 5 to the state shown in FIG. 6, and the control circuit is also switched from the automatic control mechanism 13 to the manual control mechanism 14. As a result, the blower 7 operates during the heating period, and the outside air that enters the machine room 21 from the machine room intake □ 21a is passed through the blower 7 while cooling the electrical components in the machine room, and the high-frequency generator 6 is cooled while being heated. Road switching device 17
, from the heating chamber inlet □19 to the partition plate 11 in the heating chamber 1.
Infiltrate the top of the. After that, this storm flows through the wind guide 20', is blown through the partition plate hole 11a to the finder of the door, passes around the object to be heated 2, passes through the heating chamber intake air/heating chamber exhaust row 5, and enters the high frequency heating device. leak outside. Further, the damper 17a in the air path switching device 17 is shown in FIG.
As shown in FIG. 6, the damper rotates around a shaft 17b provided on the side facing the high-frequency generator 6, and a flexible packing (see FIG. (not shown) is installed to prevent air leakage).

The above has described a mechanism that has both the automatic control mechanism 13 that automatically controls the heating time of the object to be heated 2 and the manual control mechanism 14 for the heating time using a timer, etc. The features of the present invention are as shown in FIG. As shown in FIG. 6, the automatic control mechanism 1
3, since the warm air after cooling of the high frequency generator 6 is not allowed to enter the heating chamber, there is no risk of deterioration in the accuracy of detecting the exhaust temperature rise in the heating chamber due to warm air, and the manual control mechanism 14 When using a high-frequency generator 6, hot air after cooling is put into the heating chamber 1, and this hot air is blown onto the finder of the door 3 and passed through the inside of the heating chamber 1. Even if heating is continued while a large amount of water vapor is generated from the object 2, the finder of the door 3 will not be clouded by condensation of the water vapor, and water will not accumulate in the heating chamber 1.

In addition, since the control switching device 18 can simultaneously switch the control circuits of the storm path switching device 17, the automatic control mechanism 13, and the manual control mechanism 14, the control circuits of the automatic control mechanism 13, the manual control mechanism 14, or When used in reverse, it is easy to operate and convenient to use. Further, since the damper 17a is structured to rotate around the shaft 17b, the structure is simple, economical, and highly reliable. The above explanation was based on the fact that when used in an automatic control mechanism, the oscillation of the high frequency generator 7 is stopped when the exhaust temperature reaches a preset value. It goes without saying that the present invention is also applicable when heating is continued by reducing the high frequency power. Further, in the above embodiment, the door 3 is a non-ventilated door, but the present invention is also applicable to a case where an opening is provided in the door and the door serves as a heating chamber intake and exhaust port.

Further, in the above embodiment, the blower 8 was arranged to send air to the high-frequency generator 7, but the flow of air is sucked from the high-frequency generator 7 to the blower 8, and flows through the high-frequency generator cooling air exhaust port 10'. The present invention is also applicable as a configuration.

As described above, according to the present invention, a movable damper is provided in a part of the air passage, and when the damper is used in an automatic control mechanism, the cooling air of the high frequency generator 7 is not allowed to enter the heating chamber. The heating of the object 2 to be heated can be optimized without interfering with the detection accuracy of the automatic control mechanism.

In addition, when using a manual heating time control mechanism such as a timer, hot air from the high-frequency generator's cooler is introduced into the heating chamber to prevent fogging of the finder section of the door, allowing for better heating of the heated object. can be made visible. In this way, one high-frequency heating device can automatically control heating,
Both functions of manual control heating can be properly used.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a conventional example of a high-frequency heating device that detects the exhaust temperature and controls the supply of high-frequency power, Figure 2 is a diagram showing the temperature rise characteristics of intake and exhaust air in Figure 1, and Figure 3 is a diagram showing the temperature rise characteristics of the intake and exhaust air in Figure 1. Fig. 1 is a diagram showing the relationship between the temperature rise of the heated object and the temperature rise of the exhaust sensor section, Fig. 4 is a perspective view showing an embodiment of the present invention, and Fig. 5 is a case of an automatic control mechanism. 4 is a plan sectional view of FIG. 4, and FIG. 6 is a plan sectional view of FIG. 4 in the case of a manual control mechanism. In the figure, 1...Heating chamber, 2...Heated object, 4...Temperature detection mechanism, 13...Automatic control mechanism, 14...Manual Control mechanism, 17...
...Air path switching device. Figure 1 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Claims] 1 In a high-frequency heating device that supplies high-frequency power into a heating chamber 1 that houses an object to be heated 2 to heat the object to be heated 2,
It includes a high frequency generator 6, a temperature detection mechanism 4 that detects the temperature of the ventilation air in the heating chamber, an automatic control mechanism 13 for high frequency output operated by the temperature detection mechanism, and a manual control mechanism 14 for heating time. and the automatic control mechanism 13
and an air path switching device 17 that switches the air path for ventilating the heating chamber in response to the operation of the manual control mechanism 14. When the automatic control mechanism 13 is used, the heating chamber 1 is not entered, but when the manual control mechanism is used, the heating chamber 1 is entered, and the automatic control mechanism 13 and A high-frequency heating device characterized by having a configuration in which a control circuit of a manual control mechanism 14 is switched.