JPH0348877Y2 - - Google Patents

Description

[Detailed description of the invention] "Field of application of the invention" This invention relates to a microwave oven with a heater that also has a heater in the cooking chamber, and in particular, it is concerned with temperature control during heater operation and rational air circulation. This invention relates to a microwave oven with a heater.

"Prior Art" In a conventional microwave oven with a heater, the conditions inside the oven are different when the microwave is operating and when the heater is operating, and the temperature inside the oven becomes extremely high especially when the heater is operating.

``Problems with the prior art'' As a result, there is a problem in that the temperature of the door increases.

Furthermore, when operating the heater, it is important to control its temperature, and it is necessary to accurately measure the temperature inside the cooking chamber.

``Purpose of the invention'' This invention was made to solve the above problems and meet the needs. The purpose is to accurately measure the temperature inside the room.

"Structure of the invention" The main means adopted by the invention to achieve the above object is to have a heater in the cooking chamber equipped with a door with a gap for outside air inflow, and a magnetron outside the cooking chamber to cool it. In a microwave oven with a heater equipped with a fan that can constantly take in outside air, a first air passage from a part of the cooking chamber facing the gap on the door side to the fan, provided in this first air passage. a temperature sensing means; a first shutter which opens and closes the first air passage to allow the air in the cooking chamber to flow to the fan or to stop it within the cooking chamber; and after the air is blown from the fan and cools the magnetron. a second air passage for distributing air into the cooking chamber; and a second air passage provided on the downstream side of the magnetron in the air passage direction, and opening and closing the second air passage to cool the magnetron and then directing the air to the cooking chamber. a second shutter that allows or prevents circulation; a third air passage that communicates the cooking chamber with the outside air; and a third shutter that circulates indoor air to outside air or stops it within the cooking chamber, and when the magnetron is operated to perform microwave heating, the first shutter is closed and the second shutter is closed. When the third shutter is opened and the fan is driven, and the heater is activated to heat the heater, the first shutter is opened and the second and third shutters are closed and the fan is driven. Among the above components, the first to third air passages do not necessarily have to be formed in a closed space, but are portions where air flow can be actively formed by a fan. The first to third shutters may be of any type as long as they can be driven to substantially open and close the air passages as described above. In addition to the thermistor shown in the embodiment described later, various other types of temperature detection means may be used as long as the temperature change can be detected as an electrical signal.

``Example'' Next, an example embodying the present invention will be described with reference to the attached drawings to provide an understanding of the present invention. Here, FIG. 1 is a plan cross-sectional view showing the main parts of a microwave oven with a heater according to an embodiment of the present invention.
Figure 2 shows a state in which microwave heating is being performed, Figure 2 is a diagram equivalent to Figure 1 showing a state in which heater heating is performed in the same microwave oven, and Figure 3 mainly shows the structure inside the cooking chamber of the microwave oven with a heater. FIG.

Note that the following example is only one specific example of the present invention, and is not intended to limit the technical scope of the present invention.

The microwave oven with a heater shown in the figure has an electrical component compartment 1 containing a magnetron Mg and a cooling fan F for cooling it, as shown in FIG. 1, and a heater H and a reflector R as shown in FIG. A built-in cooking chamber 3 is separated by a partition wall 4, and a large number of punch holes 6 are punched in the rear wall 5 of the microwave oven A and upstream of the cooling fan F to feed outside air to the cooling fan F. It is set up. The cooling fan F is in a state where it can always take in outside air through the punch holes 6, and also functions to cool electronic components (not shown) in addition to the magnetron Mg.
The cooling air sent by the cooling fan F usually flows primarily through the magnetron Mg toward the second air passage 13 side, which will be described later, since the flow path resistance of the passage for sending the cooling air to the electronic components is somewhat large.
However, the amount of air that can cool the electronic components is ensured.

A first air passage 7 is formed near the cooling fan F on the partition wall 4 facing the door 19 for opening and closing the cooking chamber 3, and a sensor protrudes into the first air passage 7 into the cooking chamber 3. Case 8 is connected. This sensor case 8 is provided with a temperature detector 9 (an example of temperature detection means) composed of a thermistor or the like inside, and has a large number of punched holes 10 for ventilation in the outer circumferential surface of the case. has been done. A first shutter 11 opens and closes the first air passage 7, and is operated by a signal from a control device (not shown).

The first shutter 11 functions to cause the air in the cooking chamber 3 to flow to the cooling fan F or to stop it within the cooking chamber 3.

Further, in a portion of the partition wall 4 on the opposite side from the first air passage 7 (a portion on the front side of the range), there are a number of power supply holes 12 that communicate the electrical component compartment 1 and the cooking compartment 3.
A second air passage 13 opened by the magnetron Mg
The second air passage 1 is located downstream in the air flow direction.
A second shutter 14 for opening and closing the shutter 3 is attached.

The second shutter 14 is the magnetron.
It functions to allow or prevent the air after cooling the Mg from flowing into the cooking chamber 3.

Furthermore, a side wall forming the cooking chamber 3,
A plurality of punch holes 17 forming a third air passage 16 that communicates the cooking chamber 3 with the outside air are bored in the inner part of the side wall 15 facing the partition wall 4, and a plurality of punch holes 17 are formed on the outside of the side wall. A third shutter 18 for opening and closing the air passage 16 is attached.

The third shutter 18 functions to circulate the air in the cooking chamber 3 to the outside air or to stop it within the cooking chamber 3.

The first to third shutters 11, 14, 18
are each driven to open and close by a solenoid (not shown), and the opening/closing timing thereof is determined by a signal from a control device (not shown).

Next, the operation of the above configuration will be explained to provide an understanding of the present invention. First, in the state of microwave heating, the first shutter 11 is closed as shown by a signal from the control device as shown in FIG. 1, and the second and third shutters 14, 1
After opening 8, rotate the cooling fan F. Then, due to the action of the cooling fan F, the rear wall 5 of the cabinet
After outside air flows into the electrical component room 1 from the punch hole 6 as shown by the arrow and cools the magnetron Mg,
After the air flows into the cooking chamber 3 through the second air passage 13 which is opened by the second shutter 14, it is discharged from the third air passage 16 to the outside of the refrigerator, and the food being cooked in the cooking chamber 3 is removed. The water vapor is transferred to the third air passage 1.
Discharge from 6. Further, since the first shutter 11 is closed at this time, no air flows into the air passage 7.

Next, when heating is performed by the heater H, the first shutter 11 is opened as shown in FIG. 2 by a command from the control device, and the second and third shutters 14 and 18 are opened as shown in FIG. After closing, rotate the cooling fan F. At this time, the cooling air sent by the cooling fan F passes around the magnetron Mg, and since the second shutter 14 is closed, it flows toward the electronic component side. Since the first air passage 7 is open in this way, the inside of the first air passage 7 and the sensor case 8 communicating therewith, as well as the cooking chamber 3, are brought into negative pressure by the cooling fan F. As shown by the arrow, the air inside the cooking chamber 3 flows through the sensor case 8 and along the temperature detector 9, and the temperature inside the cooking chamber 3 is detected. Furthermore, as a result of the inside of the cooking chamber 3 being exposed to negative pressure as described above, gaps 20a and 2 at the contact surface between the door 19 that opens and closes the cooking chamber 3 and the wall of the oven.
Outside air flows in from 0b as shown by the arrow, and the door 19 is cooled.

In this case, outside air is taken in through the gaps 20a and 20b, and is efficiently diffused and heated in the cooking chamber 3 toward the temperature sensor 9 provided at a position facing the gaps 20a and 20b. Since the temperature inside the cooking chamber 3 can be detected with high accuracy.

``Effect of the invention'' As described above, the present invention has a heater inside the cooking chamber, which is equipped with a door with a gap for the inflow of outside air, and a magnetron outside the cooking chamber and a fan that can constantly take in outside air to cool it. The microwave oven with a heater provided therein includes: a first air passage from a portion of the cooking chamber facing the gap on the door side to the fan; a temperature detection means provided in the first air passage; a first shutter which opens and closes a first air passage to allow air in the cooking chamber to flow to the fan or to stop the air within the cooking chamber; a second air passage for blowing air; and a second air passage provided downstream of the magnetron in the air flow direction and opening and closing the second air passage to allow or prevent air from flowing into the cooking chamber after cooling the magnetron. a second shutter, a third air passage that communicates the cooking chamber with the outside air, and a third air passage that is disposed in the third air passage and opens and closes in conjunction with the second shutter to circulate the air in the cooking chamber to the outside air. and a third shutter that can be moved or stopped within the cooking chamber, and when the magnetron is operated to perform microwave heating, the first shutter is
When the shutter is closed and the second and third shutters are opened, the fan is driven, and the heater is activated to heat the heater, the first shutter is opened and the second and third shutters are opened. Since this is a microwave oven with a heater that is characterized in that the fan is driven when the shutter is closed, the temperature in the cooking chamber when the heater is heated can be detected extremely accurately, and the door can be protected from the heat generated when the heater is activated. This product has successfully extended the life of the microwave oven.

[Brief explanation of the drawing]

FIG. 1 is a plan cross-sectional view showing the main parts of a microwave oven with a heater according to an embodiment of the present invention, showing the state in which microwave heating is being performed, and FIG. FIG. 3 is a front sectional view mainly showing the structure inside the cooking chamber of the microwave oven with a heater. Explanation of symbols, Mg...Magnetron, F...Cooling fan, H...Heater, R...Reflector, A...
Microwave oven, 1...Electrical equipment room, 3...Cooking room,
4... Bulkhead, 6, 10, 12... Punch hole, 7,
13, 16...First to third air passages, 9...Temperature detector, 11, 14, 18... First to third shutters. 19...Door, 20a, 20b...Gap.

Claims (1)

[Scope of Claim for Utility Model Registration] A microwave oven equipped with a heater, which is equipped with a heater inside the cooking chamber that has a door with a gap for outside air to flow in, and a magnetron outside the cooking chamber and a fan that can constantly draw in outside air to cool it. a first air passage from a portion of the cooking chamber facing the gap on the door side to the fan; a temperature detection means provided in the first air passage;
a first shutter which opens and closes the first air passage to allow the air in the cooking chamber to flow to the fan or to stop the air within the cooking chamber; and a second air passage disposed downstream of the magnetron in the air flow direction, and opening and closing the second air passage to allow or prevent air from flowing into the cooking chamber after cooling the magnetron. a second shutter that communicates the cooking chamber with the outside air; and a third air passage that is disposed in the third air passage and opens and closes in conjunction with the second shutter to connect the air inside the cooking chamber to the outside air. a third shutter to allow the water to flow to the cooking chamber or to be stopped in the cooking chamber, and when the magnetron is operated to perform microwave heating, the first shutter is closed and the second and third shutters are closed. When the first shutter is opened and the second and third shutters are closed, the fan is driven, and when the heater is operated to heat the heater, the first shutter is opened and the second and third shutters are closed, and the fan is driven. A microwave oven with a heater.