JPH03168525A - Heating cooking oven - Google Patents

Abstract

PURPOSE:To prevent thermal influence on an electronic controller, etc., by providing a switching damper having a spring of a shape memory alloy at a part of a blower duct, and intermittently operating the cooling blower by a command from the controller. CONSTITUTION:When a heater 8, a hot air blower 9 are operated and a temperature in an oven 2 becomes high at about 300 deg.C, a switching damper 23 closes a vent hole 19 by a coil spring 25 of a shape memory alloy. After cooling air of a cooling blower 14 forcibly cools a magnetron 7 of a machine room 3, an electronic controller 15, etc., and is then exhausted from an exhaust port 17. The blower 14 is intermittently turned ON, OFF at a predetermined time interval at the heater 8, the blower 9 by a command from the controller 15 according to the detected temperature of a temperature sensor 26 to hold the temperature in the oven 2 constant and to safely and effectively cool the controller 15 of the room 3.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a heating cooking device for cooking food by high-frequency heating and a heating heater in an oven, for example.
In particular, the present invention relates to a cooling device that cools an electronic control circuit and the like in a machine room in this cooking device.

(Prior Art) This type of heating cooking apparatus that has already been proposed is constructed as shown in FIG.

That is, in FIG. 8, an oven frame 4 in which an oven 2 and a machine room 3 are divided is provided in a box-shaped case body 1 equipped with an opening/closing door 1a and an operation panel 1b. An excitation port 5 is bored in the top plate of the oven frame 4, and a waveguide 6 is provided in the top plate of the oven frame 4 opposite to the excitation port 5. It is attached so as to cover the mouth 5. A well-known magnetron 7 is attached to one end of the waveguide 6, and a heater 8 and a hot air blower 9 are attached to the back of the oven frame 4 through a partition plate 10. It is being Furthermore, this partition plate 10 has each hot air outlet 1 formed by punching.
1a and llb are punched, and a suction port 12 is punched in the middle of the partition plate 10. Additionally, on one side of the oven frame 4, there is a heat shield plate 1.
3 is erected to block high heat from the oven 2, and the machine area 3 is surrounded by the heat shield plate 13.
Inside, an electronic control circuit 15 in which a cooling blower 14 is attached to the back surface of the magnetron 7 and the operation panel 1b,
It is provided to cool a high voltage transformer (not shown) and the like. Further, an intake port 16 is provided in the back plate of the case body 1 where the machine room 3 is located to supply cold air, and the bottom plate of the case body 1 where the machine room 3 is located is provided with an air intake port 16 for supplying cold air. An exhaust port 17 is bored in the. Further, an air duct 18 is connected between the magnetron 7 and the heat shield plate 13, and one opening of the air duct 18 is bored in one side plate of the oven frame 4. It is provided so as to communicate with the oven 2 through one ventilation hole. Furthermore, an exhaust hole 20 is provided in the other side plate of the oven frame 4, and an exhaust duct 21 is provided beside the exhaust hole 20 through an exhaust port provided in the back of the case body 1. 22.

Therefore, in the heating cooking device described above, when cooking in the microwave, by energizing the magnetron 7, the radio waves of the magnetron 7 pass through the waveguide 6 and the excitation port 5 to high-frequency heat the food to be cooked in the oven 2. On the other hand, the cooling air from the cooling blower 14 forcibly cools the magnetron 7, electronic control circuit 15, etc. in the machine room 3, and then is exhausted to the outside of the machine through the exhaust port 17. A part of the cooling air from the cooling blower 14 cools the magnetron 7 in the machine room 3 and then passes through the ventilation duct 18 and the ventilation hole 19 to release the steam (steam) in the oven 2 to the steam exhaust hole 20. , an exhaust duct 21 and an exhaust port 22 to exhaust the air outside the machine.

On the other hand, during heating cooking with the heater, by energizing the heating heater 8 and the hot air blower 9, the heating heater 8 circulates and heats the inside of the oven 2 with the fluid caused by the hot air blower 9, thereby heating the food to be cooked in the oven 2. At the same time, the cooling air from the cooling blower 14 forcibly cools the magnetron 7, electronic control circuit 15, etc. in the machine room 3, and is then exhausted to the outside of the machine through the exhaust port 17. . or,
A part of the cooling air from the cooling blower 14 is supplied to the machine room 3.
After cooling the magnetron 7 inside, the blower duct 18
, steam inside the oven 2 through one ventilation hole.
is exhausted to the outside of the machine through a steam exhaust hole 20, an exhaust duct 21, and an exhaust port 22.

(Problem to be Solved by the Invention) However, since the heating temperature of the food to be cooked in the oven 2 in the above-mentioned heating cooking device is usually about 250°C, the above-mentioned machine room Although there was no risk of malfunction due to thermal influence on the electronic control circuit 15 etc. built into the oven 2, recent heating cooking devices equipped with a heater 8 and a magnetron 7 The electronic control circuit 15 incorporated in the machine room 3 is heated to a high temperature of about 300°C or higher.
etc., it is necessary to use electronic parts that can withstand high temperatures of about 300'C inside the oven 2, which makes them expensive.

On the other hand, even if the high heat due to radiant heat or thermal conduction from the oven 2 is blocked using a heat shield or heat insulating material, the electronic control circuit 15 etc. incorporated in the machine room 3 can be safely and reliably shielded from heat. It is difficult to do so.

The present invention has been made in view of the above-mentioned circumstances, and is a heating cooking device equipped with a heater and a magnetron that is installed in the machine room even if the inside of the oven is heated to a high temperature of about 300°C or higher. The purpose of the present invention is to provide a heating cooking device that safely and reliably cools electronic control circuits, etc., and prevents adverse thermal effects on the electronic control circuits, etc., thereby improving safety and reliability. .

[Structure of the invention]

(Means for Solving the Problems and Their Effects) The present invention provides an oven frame in which an oven and a machine room are divided and formed in a case body, and a heating heater and a magnetron are provided in the oven frame. In the apparatus, an electronic control circuit and a cooling blower are provided in the machine room, the magnetron and a ventilation hole bored in a part of the oven frame are connected by a ventilation duct, and a part of the ventilation duct has a shape. A switching damper equipped with a spring made of a memory alloy is provided to open and close the vent, and when the heater is heated, the switching damper closes the vent, and the cooling blower is intermittently activated by a command from the electronic control circuit. Even if the inside of the oven is heated to a high temperature of about 300 degrees Celsius, the electronic control circuit built into the machine room can be safely and reliably cooled. This is designed to prevent malfunctions by preventing thermal effects on circuits, etc., and to improve safety and reliability.

(Example) Hereinafter, the present invention will be described with reference to an illustrated embodiment.

Note that the present invention includes the same constituent members as those in the above-mentioned specific example.
The same reference numerals will be used to explain.

In FIGS. 1 to 3, reference numeral 1 denotes a box-shaped case body equipped with an opening/closing door 1a and an operation panel 1b,
Inside this case body 1, there is provided an oven frame 4 which is formed by dividing an oven 2 and a machine room 3, and an excitation port 5 is bored in the top of this oven frame 4. A waveguide 6 is attached to the top plate of the oven frame 4, where the excitation port 5 is located, so as to cover the excitation port 5. A well-known magnetron 7 is attached to one end of the waveguide 6, and a heater 8 and a hot air blower 9 are attached to the back of the oven frame 4 through a partition plate 10. It is being Furthermore, this partition plate 10 has each hot air outlet 11a, ll by punching.
b, and a suction port 12 is punched in the middle of the partition plate 10. Furthermore, a heat shield plate 13 is erected on one side of the oven frame 4 to block high heat from the oven 2, and the machine room 3 is surrounded by the heat shield plate 13. Inside, a cooling blower 14 is provided to cool the magnetron 7, an electronic control circuit 15 attached to the back surface of the operation panel 1b, a high voltage transformer (not shown), and the like. Further, an intake port 16 is provided in the back plate of the case body 1 where the machine room 3 is located to supply cold air, and the bottom plate of the case body 1 where the machine room 3 is located is provided with an air intake port 16 for supplying cold air. An exhaust port 17 is bored in the. moreover,
A ventilation duct 18 is connected between the magnetron 7 and the heat shield plate 13, and one opening of the ventilation duct 18 passes through a ventilation hole 19 bored in one side plate of the oven frame 4. It is provided so as to communicate with the oven 2 mentioned above. Furthermore, an exhaust hole 20 is bored in the other side plate of the oven frame 4, and an exhaust duct 21 is provided beside the exhaust hole 20, which is an exhaust duct 21 bored in the back plate of the case body 1. It is provided so as to communicate with the port 22.

On the other hand, a switching damper 23 is provided in a part of the air duct 14 so as to open and close the vent 19 with a support shaft 24, and this switching damper 23 is equipped with a coil spring 25 made of a shape memory alloy. The switching damper 18 is wound so that the ventilation hole 19 is closed by the switching damper 18 when the heater is heated at a high temperature of about 300°C. Further, a temperature sensor 26 such as a thermistor is attached to the oven frame 4 in the oven 2 to detect the heating temperature in the oven 2. It is connected to the control circuit 15. Furthermore, as shown in FIG. 6, this electronic control circuit 15 includes an electromagnetic switch (electromagnetic relay) 9a of the hot air blower 9 connected to the electric circuit of the cooking device, and an electromagnetic switch (electromagnetic relay) 9a of the hot air blower 9 connected to the electric circuit of the cooking device. An electromagnetic switch (electromagnetic relay) 14a is connected.

Note that the above electric circuit includes a first circuit that switches on and off the power to the power supply.
A door switch 27a1 and a second door switch 27b are connected in series.

Therefore, when cooking in the microwave, by energizing the magnetron 7, the radio waves of the magnetron 7 pass through the waveguide 6 and the excitation port 5 to high-frequency heat the food to be cooked in the oven 2, and on the other hand, the The cooling air from the cooling blower 14 forcibly cools the magnetron 7, electronic control circuit 15, etc. in the machine room 3, and then is exhausted to the outside of the machine through the exhaust port 17. A portion of the cooling air from the cooling blower 14 cools the magnetron 7 in the machine room 3, and then passes through the blower duct 18 and one ventilation hole to direct the steam (steam) in the oven 2 to the steam exhaust hole. 20, an exhaust duct 21, and an exhaust port 22 to exhaust the air to the outside of the machine.

On the other hand, during heating cooking with the heater, by energizing the heater 8 and the hot air blower 9, the heater 8 circulates and heats the inside of the oven 2 with fluid by the hot air blower 9, and heats the food to be cooked in the open 2. When heated and the switching damper 23 reaches a high temperature of about 300° C., the one ventilation hole is closed by the action of the coil spring 25 made of a shape memory alloy.

On the other hand, the cooling air from the cooling blower 14 is supplied to the machine room 3.
After forcibly cooling the magnetron 7, electronic control circuit 15, etc. inside, the air is exhausted to the outside of the machine through the exhaust port 17. , based on the temperature detected by the temperature sensor 26, and in response to a command from the electronic control circuit 15, the heater 8 and the hot air blower 9 are intermittently turned ON and OFF at fixed time intervals to cool the inside of the oven 2. Even if the temperature in the machine room 3 is maintained at a temperature of about 300°C, the electronic control circuit 15, etc. in the machine room 3 is cooled, and the inside of the oven is heated to a high temperature of about 300°C, the temperature in the machine room 3 is The electronic control circuit 15 etc. incorporated in the electronic control circuit 15 etc. is cooled safely and reliably, and the electronic control circuit 15 etc. are not affected by heat to prevent malfunctions and improve safety and reliability. ing.

〔Effect of the invention〕

As described above, according to the present invention, in a heating cooking apparatus in which an open frame body in which an oven and a machine room are separated and formed in a case body, and a heating heater and a magnetron are provided in this oven frame body, the above-mentioned machine An electronic control circuit and a cooling blower are installed in the chamber, the magnetron is connected to a ventilation hole drilled in a part of the oven frame through a ventilation duct, and a spring made of a shape memory alloy is installed in a part of the ventilation duct. A switching damper is provided to open and close the vent, and when the heater heats up, the vent is closed by the switching damper, and the cooling blower is intermittently operated according to a command from the electronic control circuit. Since we are trying to cool the electronic control circuit etc., the inside of the above open is approximately 3.
Even when heated to temperatures as high as 00°C, the electronic control circuits built into the machine room can be safely and reliably cooled, and the electronic control circuits are not affected by heat. It has excellent effects such as preventing malfunctions, discoloration and deformation of plastic doors and operation panels, and improving safety and reliability.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the heating cooking apparatus of the present invention, FIGS. 2 and 3 are diagrams for explaining the action of the present invention, and FIG.
FIG. 5 is a cross-sectional view of the switching damper incorporated in the present invention, FIG. 6 is an electric circuit diagram incorporated in the present invention, and FIG. 7 is an explanatory diagram of the operation of the present invention. FIG. 8 is a cross-sectional view of a heating cooking device that has already been proposed. DESCRIPTION OF SYMBOLS 1... Case body, 2... Oven, 4... Oven frame, 7... Magnetron, 8... Heater, 9... Hot air blower, 14... Cooling blower, 15
...Temperature sensor, 18...Blower duct, 19...
Ventilation port, 23... Switching damper, 25... Spring made of shape memory alloy, 26... Temperature sensor.

Claims (1)

[Claims] In a heating cooking apparatus in which an oven frame is provided with an oven and a machine room separated into a case body, and a heater and a magnetron are provided in the oven frame, an electronic control circuit and a cooling blower are provided in the machine room. , the magnetron and a vent hole bored in a part of the oven frame body are connected by a ventilation duct, and a switching damper provided with a spring made of a shape memory alloy in a part of the ventilation duct opens and closes the vent hole. When the heater heats up, the ventilation port is closed by the switching damper, and the cooling blower is intermittently operated according to a command from the electronic control circuit to cool the electronic control circuit, etc. A heating cooking device featuring: