JPS6313674Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a high-frequency heating device, and provides a novel high-frequency heating device equipped with a heater for electric cooking in a heating chamber.

The present invention will be explained below with reference to the illustrated embodiment. 1 is a main body consisting of an outer case 2 and a heating box 4 provided inside the outer case and has a heating chamber 3 inside; 5 is an opening of the heating chamber 3 of this main body. A door that can be opened and closed freely; 6 is a substantially W-shaped sheathed heater that is removably installed at the top of the heating chamber 3; 7 is a U-shaped sheathed heater that is also removably installed at the bottom of the heating chamber 3; 8; 1 is a turntable, 9 is a magnetron that is attached to the upper side of the heating chamber 3 and irradiates high frequency waves into the heating chamber 3 through a waveguide 10, and 11 is a magnetron that sucks outside air through an intake hole 12 provided at the bottom of the main body 1. This is a blower that forcibly blows air to the heat generating part of the magnetron 9, and is not driven while the heaters 6 and 7 are energized.
It is designed to be driven while the magnetron 9 is being driven.

13 is a duct provided on the opposite side of the blower 11 across the magnetron 9, and guides the wind that cools the magnetron 9 into the heating chamber 3 through an introduction hole 14 provided on the wall of the heating chamber 3; 15 is this introduction hole. As shown in FIG.
It is located slightly above the position 4 and the position of the upper heater 6.

Reference numeral 16 denotes an exhaust duct with an opening at one end attached to the outside of the heating chamber 3 in correspondence with the exhaust hole 15, and an opening at the other end aligned with the exhaust port 17 formed in the outer case 2, with an exhaust air passage S inside. is forming.

18 is a heat insulating material such as asbestos that is closely attached to the outer surface of the heating chamber 3; 19 is a partition plate interposed between the magnetron 9 and the blower 11 and the heating chamber 3; 2;
0 is a high-voltage transformer installed directly above the intake hole 12, 21 is the main body of a liquid expansion type thermostat 22 that controls energization of the heaters 6 and 7 in order to control the temperature inside the heating chamber 3 during electric cooking, and 23 is a main body of a liquid expansion thermostat 22. The temperature sensing portion of the thermostat has a rod shape with a length approximately equal to the width of the exhaust duct 16, and is held approximately horizontally within the exhaust duct 16 with both ends supported by support plates 24. However, as shown in FIG. 3, the position of this temperature sensing portion is set a predetermined distance A above the top of the discharge hole 15 and close to the wall surface of the heating chamber 3.

26 is the temperature detection section 23 and the thermostat main body 2
1, 27 is an operation panel provided on the front of the main body, 25 is a heating start switch provided on the surface of this operation panel, 28 is a temperature setting knob for the thermostat 22, also provided on the operation panel 27, 2
9 is a heater 6 similarly arranged on the operation panel 27;
An energization selection switch 7 selects three states: simultaneous energization of both heaters 6 and 7, and energization of only one of each heater.

30 is a changeover switch for switching between high-frequency heating and electric heating; 31 is an operation knob for a timer switch (not shown) for setting high-frequency heating time and electric heating time; 32 is a pair of opposing side wall surfaces of heating chamber 3; A supporting tool 33 for the heated object mounting shelf (not shown) provided is a ventilation hole.

In the above configuration, if you want to perform electric cooking now, set the changeover switch 30 to the electric cooking side, select the selection switch 29, and turn on the switch 25, then both or one of the heaters 6 and 7 will turn on. When the power is turned on, the turntable 8 is also operated at the same time, and the food placed on the table can be cooked. Furthermore, if a shelf with foods, etc. placed thereon is placed on the support 32 at an appropriate height, those foods will be heated and cooked in the same way.

During such electric cooking, heating chamber 3
Since the blower 11 is stopped so as not to blow air into the heating chamber 3, the heating chamber 3 is filled with hot air. The high-temperature hot air in the ceiling of the heating chamber is discharged to the outside little by little from the exhaust hole 15 through the exhaust duct 16 and the exhaust port 17 as shown by the arrow in FIG. 3 due to its own upward movement. .

By the way, the temperature detection section 2 used here
3 simply contains liquid, so
There is no need to worry about electrical leakage, and since it is not affected by anything other than heat, there is no need to worry about malfunctions.

Therefore, since the ambient temperature in the heating chamber 3, that is, the hot air temperature, is detected by the temperature detection section 23, the temperature in the heating chamber 3 is maintained at the desired cooking temperature preset by the temperature setting knob 28, and the timer is activated. When the time set by a switch (not shown) has elapsed, the electricity to both heaters 6 and 7 is completely cut off, and the electric cooking ends.

On the other hand, when performing high-frequency heating, switch the changeover switch 30 to the high-frequency heating side, set the heating time with the operation knob 31 of the timer switch (not shown), and turn on the start switch 25, and the turntable 8 will rotate. At the same time, since high frequency waves are irradiated from the magnetron 9 into the heating chamber 3 via the waveguide 10, the high frequency waves are irradiated onto the turntable 8 or the support 32.
Foods placed on shelves are heated from inside,
Cook. During this high-frequency heating, the blower 11 is operated to send air after cooling the magnetron 9 into the heating chamber 3, forcing water vapor generated from the object to be heated to the outside of the main body 1 through the exhaust hole 15 and the exhaust duct 16. to be discharged.

During such high frequency heating, thermostat 2
Since the temperature detecting section 23 of No. 2 is located outside the heating chamber 3, which is not exposed to high frequency irradiation, there is no fear that this detecting section will be damaged or deteriorated.

Here, the size of the discharge hole 15 is set to a size that does not allow the high frequency waves irradiated into the heating chamber 3 to pass through, but even if some leakage occurs, the temperature detection section 23 will simply detect that the liquid has thermally expanded. Since it only causes a physical change, there is no worry that a weak current will be generated and malfunction will occur.

Moreover, even if a large amount of water vapor is contained in the exhaust gas, there is only liquid in the temperature detection part 23 and there is no electrical connection at all, so there is no risk of electrical leakage. It reacts only to heat and is reliably transmitted to the remote body 21 of the thermostat 22 by a physical change of expansion.

Moreover, even if the wall surrounding the liquid in the temperature sensing part 23 were to cover, there is no electrical wiring in the temperature sensing part 23, so there is no risk of electric shock; the liquid would simply leak; If liquid leaks, no physical change will occur in the body 21 of the thermostat 22, so it can be immediately determined that the liquid has leaked, and false information will not be transmitted to the body 21 of the thermostat 22 due to the liquid leaking. There is no need to worry about it being transmitted.

As described above, the high-frequency heating device of this invention is equipped with a heater for electric heating, so in addition to the conventional cooking using high frequency alone, various types of cooking can be efficiently done using electric heating alone or in combination with high frequency. In addition, the temperature detection part of the thermostat that regulates the cooking temperature during electric cooking is placed in the exhaust air passage that communicates with the heating chamber through the exhaust hole, so the temperature detection part itself is protected from high-frequency irradiation. Needless to say, there is no risk of sparks occurring near the mounting portion of the temperature sensing portion or leakage of high frequency waves to the outside via the temperature sensing portion.

Furthermore, since the temperature detection part is provided close to the top of the discharge hole, it is possible to reliably detect the temperature of the hot air in the upper part of the heating chamber, where the temperature is highest, and it has good ability to follow temperature changes. It also has the effect of allowing you to make delicate temperature adjustments.

Moreover, since the thermostat is a liquid expansion type, there is simply liquid in the temperature sensing part, so there is no fear of electrical malfunctions, short circuits, or electric shocks, and it is not affected by water vapor. This system has the unique effect of being able to identify any leakage immediately, without worrying about the occurrence of false information.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a high frequency heating device according to this invention, FIG. 2 is a partially cutaway plan view thereof, and FIG. 3 is a sectional view taken along the line -- in FIG. 2. In the figure, 3 is a heating chamber, 6 and 7 are heaters, 9 is a magnetron, 11 is a blower, 15 is an exhaust hole, 16 is an exhaust duct, 22 is a thermostat, 23 is a temperature detection unit, and S is an exhaust air path. .

Claims (1)

[Scope of utility model registration request] An electric heater and a plurality of hot air exhaust holes of a size that does not allow high frequency waves to pass through are installed in the upper part of the heating chamber.
An exhaust air passage is formed in succession to these plurality of exhaust holes, and in this exhaust air passage, a temperature detection device for a liquid expansion type thermostat that controls the energization of the heater is installed near the top of the exhaust hole. A high-frequency heating device consisting of a section.