JP2011237123A - High frequency cooking device - Google Patents

Abstract

An object of the present invention is to provide a high-frequency cooking apparatus capable of measuring an object temperature with an infrared temperature sensor even when a heating chamber is full of steam.
A dielectric bottom tray (33) is fitted to the bottom of a heating chamber (20) of a high frequency cooking device (1). Below the bottom tray 33 is configured as an antenna chamber 32 into which high frequency is introduced. Outside the antenna chamber 32, an infrared temperature sensor 60 that measures the temperature of an object placed on the bottom tray 33 through the space of the antenna chamber 32 is disposed. The infrared temperature sensor 60 measures temperature through a through hole 32 a formed in the bottom of the antenna chamber 32. An opening 34 a that passes through the field of view of the infrared temperature sensor 60 is formed in the rotating antenna 34 disposed in the antenna chamber 32.
[Selection] Figure 3

Description

  The present invention relates to a high-frequency cooking apparatus.

  A high-frequency cooking apparatus that vibrates food molecules with high frequency (microwave) and thereby heats the food from the inside is generally known as “microwave oven” and has become a household necessity.

  In recent high-frequency cooking apparatuses, an apparatus that controls the heating by monitoring the temperature of the food being heated with an infrared temperature sensor is increasing. An example of this can be seen in US Pat.

  The high-frequency cooking device described in Patent Document 1 detects temperature information of food placed on a turntable-less food placing table using an infrared temperature sensor disposed above the heating chamber. Moreover, the temperature information of the food mounting table is detected by a contact temperature sensor such as a thermocouple.

JP 2004-219918 A

  When measuring the temperature with an infrared temperature sensor, if there is an obstacle between the object to be measured, the measurement accuracy is lowered. In an oven-type cooking apparatus, steam generated from food or steam during steam cooking is an obstacle. When the distance from the food to the infrared temperature sensor is long as in the device described in Patent Document 1, the infrared temperature sensor measures the temperature of the steam existing between the food and the food temperature accurately. Can not be. This is a particularly serious problem in a cooking apparatus that performs steam cooking by introducing steam into the heating chamber.

  The present invention has been made in view of the above points, and an object thereof is to provide a high-frequency cooking apparatus capable of measuring an object temperature with an infrared temperature sensor even in a state where steam is filled in a heating chamber.

  According to a preferred embodiment of the present invention, the high-frequency cooking apparatus has a cooking mode for introducing steam into the heating chamber, and a bottom tray made of a dielectric material is fitted in the bottom of the heating chamber, and a high frequency is below the bottom tray. An infrared temperature sensor configured to measure the temperature of an object placed on the bottom tray through the space of the antenna chamber is arranged while being configured as an antenna chamber to be introduced.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the infrared temperature sensor is disposed outside the antenna chamber and measures temperature through a through-hole formed in the bottom of the antenna chamber.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the through hole is of a size that prevents high-frequency leakage.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the rotating antenna disposed in the antenna chamber has an opening that passes through the visual field of the infrared temperature sensor.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the rotating antenna is in a rotation stopped state at a position where the opening overlaps the visual field of the infrared temperature sensor.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the bottom tray is marked with a temperature detection position by the infrared temperature sensor.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the bottom tray is subjected to water repellent treatment at least at a temperature detection position by the infrared temperature sensor.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the bottom tray is inclined at least at a temperature detection position by the infrared temperature sensor.

  According to a preferred embodiment of the present invention, in the high-frequency cooking apparatus having a steam configuration, the bottom tray is formed such that the temperature detection position by the infrared temperature sensor is higher than the surroundings.

  According to the present invention, since the infrared temperature sensor is partitioned from the inside of the heating chamber by the bottom tray, and steam does not enter the space to the object placed on the bottom tray, the heating chamber is filled with steam. However, the temperature of the object placed on the tray can be accurately measured. Moreover, since the distance to the object whose temperature is measured is constant, the infrared temperature sensor can reduce measurement errors.

It is a front view showing one embodiment of the high frequency cooking device concerning the present invention. It is the general | schematic vertical sectional view which looked at the high frequency cooking apparatus of FIG. 1 from the front. It is the schematic vertical sectional view which looked at the high frequency cooking apparatus of FIG. 1 from the side. It is a top view of the antenna which distributes a high frequency. It is a block block diagram of the high frequency cooking apparatus of FIG.

  Hereinafter, the structure of the high frequency cooking device 1 according to the embodiment of the present invention will be described with reference to the drawings. In FIG. 1, the upper and lower sides of the paper coincide with the upper and lower sides of the high-frequency cooking device 1. The left side of the paper is the left side of the high-frequency cooking device 1, and the right side of the paper is the right side of the high-frequency cooking device 1.

  The high frequency cooking device 1 includes a housing 10 made of a rectangular parallelepiped sheet metal structure. A heating chamber 20 made of a sheet metal structure having a rectangular parallelepiped shape is provided inside the housing 10. The heating chamber 20 has an opening on the front side of the housing 10. A sheet metal door 11 that opens and closes the opening of the heating chamber 20 is provided on the front surface of the housing 10. The door 11 rotates in the vertical plane with the lower part as a fulcrum, and by holding the upper handle 12 and pulling it forward, the door 11 is in a 90 ° posture from the vertical fully closed position shown in FIG. 3 to the horizontal fully open position. Can be converted.

  The door 11 is formed with a window 13 through which the inside of the heating chamber 20 can be seen. The window 13 is fitted with a door screen 14 in which punching metal is sandwiched between two glass plates to prevent leakage of radio waves while maintaining transparency. In addition to the door screen 14, the door 11 is provided with radio wave leakage prevention measures, a gasket for preventing gas leakage is arranged between the heating chamber and a biasing device or a lock device for keeping the closed state. Since they are all well-known techniques, detailed description thereof is omitted.

  Steam generated from ingredients during cooking or steam used for cooking may condense on the inner surface of the door 11. A dew tray 15 is disposed below the door 11 so that the condensed water does not drip and wet the installation location of the heating cooker 1.

  An operation unit 16 is formed in the case 10 on the right side of the door 11. A group of operation keys 16b and a dial 16c are arranged on the operation unit cover 16a constituting a part of the housing 10 as an operation interface. A display device 16d is disposed above the operation key 16b.

  The housing 10 is supported on a table or a table by the legs 17. The leg portions 17 are provided at two locations on the left and right sides of the front side and the back side, and form a four-point support.

  Next, the internal structure of the high frequency cooking device 1 will be described. An air supply fan 21 is provided outside the right side wall (hereinafter referred to as “right side wall”) of the heating chamber 20. The air supply fan 21 sends air into the heating chamber 20 through an air supply port (not shown) formed on the right side wall of the heating chamber 20.

  An exhaust duct 22 is provided outside the right side wall of the heating chamber 20. One end of the exhaust duct 22 is connected to an exhaust port (not shown) formed on the right side wall of the heating chamber 20. A humidity sensor 71 (see FIG. 5) is arranged inside the exhaust duct 22 at a position slightly entering from the exhaust port.

  The air outlet 22a of the exhaust duct 22 has a face on the top plate of the housing 10. Connected to the exhaust duct 22 is an exhaust dilution fan 23 for sending air into the exhaust duct 22. When the exhaust dilution fan 23 sends air into the exhaust duct 22, an air flow that blows out from the blower outlet 22a is generated. The gas in the heating chamber 20 is sucked out by the air flow, diluted by the air flow, and discharged from the air outlet 22a.

  A temperature sensor 24 made of a thermistor is disposed on the ceiling of the heating chamber 20. In addition, two sets of upper and lower tray receivers facing each other at the same height are formed on the right side wall and the left side wall of the heating chamber 20. Both the upper tray receiver 25 and the lower tray receiver 26 are ridge-shaped protrusions protruding from the right side wall or the left side wall. The protrusion extends horizontally in the direction of the depth of the heating chamber 20.

  The food is supported by a tray or rack (not shown) supported by the upper tray receiver 25 or the lower tray receiver 26. However, if the food is large, if it is put in a container such as a pan, or if it is placed on a cooking plate, it may be placed on the bottom tray described later .

  The high-frequency cooking device 1 is capable of heating with high frequency, heating with hot air, heating with steam, and heating that mixes them. Then, the structure of each heating means is demonstrated.

  In the space between the bottom of the heating chamber 20 and the bottom of the housing 10, a magnetron 30 and a waveguide 31 that supplies the high frequency generated by the magnetron 30 to the heating chamber 20 are disposed. The waveguide 31 is connected to an antenna chamber 32 that extends below the bottom of the heating chamber 20. A bottom tray 33 made of a dielectric material such as glass or ceramic is fitted into the bottom of the heating chamber 20. The bottom tray 33 separates the antenna chamber 32 from the heating chamber 20, and is a bottom plate for the heating chamber 20 and a ceiling plate for the antenna chamber 32.

  A rotating antenna 34 is disposed in the antenna chamber 32. The rotating antenna 34 is attached to the upper end of the shaft 35a of the antenna motor 35, and controls the distribution of high frequency in the heating chamber 20 while continuously rotating by the antenna motor 35. A switch cam 36 is fixed to the shaft 35a, and a rotational position detection switch 37 is combined with the switch cam 36 so that the rotational position of the rotating antenna 34 can be known.

  An electrical component housing portion 38 is provided in a space between the bottom of the heating chamber 20 and the bottom of the housing 10, and a high frequency drive power source 72 (see FIG. 5) is mounted on the control board therein. Since both the high-frequency driving power source 72 and the magnetron 30 are heat-generating components during high-frequency heating, that is, components that generate considerable heat during high-frequency oscillation, a cooling fan 39 that forcibly air-cools these components is installed on the bottom of the casing 10.

  The cooling fan 39 includes a fan casing 39a, a cooling fan motor 39b with a shaft, and a sirocco fan 39c fixed to the upper end of the shaft of the cooling fan motor 39b. When the cooling fan motor 39b is driven to rotate the sirocco fan 39c, external air is sucked from an air inlet 39d (consisting of a set of a plurality of small holes) formed at the bottom of the housing 10, and the air is sucked into the fan. By vigorously discharging horizontally from the discharge port 39e of the casing 39a, the heat generating component is cooled by air during high-frequency heating.

  Heating with hot air is realized by a convection heater unit 40 provided outside the inner wall of the heating chamber 20. The convection heater unit 40 is configured by a dish-shaped heat insulation fan casing 41 fixed to the outer surface of the back wall of the heating chamber 20, and a space surrounded by the heat insulation fan casing 41 and the back wall of the heating chamber 20. A convection fan 42 arranged, a convection motor 43 that rotates the convection fan 42, and an annular convection heater 44 that surrounds the outer periphery of the convection fan 42.

  The convection fan 42 is a centrifugal fan, and sucks air inside the heating chamber 20 from an air inlet 45 formed in the center of the inner wall of the heating chamber 20 and discharges it in the outer peripheral direction. It is made to erupt into the heating chamber 20 from the blowing ports 46 formed in a total of six places on the back wall of the heating chamber 20 in a surrounding form. If the convection heater 44 is energized, the air discharged from the convection fan 42 is heated, and hot air is blown out from the air outlet 46. Note that both the air inlet 45 and the air outlet 46 are composed of a plurality of small holes.

  It is the steam generator 50 installed outside the right side wall of the heating chamber 20 that realizes heating by steam. The steam generator 50 can generate saturated steam or superheated steam.

  The steam generator 50 includes a housing 51 that is flat in the left-right direction when viewed from the front. Inside the housing 51, a steam generating heater 52 made of a sheathed heater is provided.

  The housing 51 is supplied with water from a water supply tank 54 by a water supply pump 53. The housing 51 is formed with a horizontal steam outlet 55 through which steam generated inside is blown into the heating chamber 20.

  A through hole 32 a is formed at the bottom of the antenna chamber 32. An infrared temperature sensor 60 for measuring the temperature of an object existing above is fixed below the antenna chamber 32 through the through hole 32a. The through hole 32a is sized to prevent high frequency leakage from the antenna chamber 32.

  The infrared temperature sensor 60 is disposed at a location relatively close to the center of the bottom tray 33. This location is also a position relatively close to the center of the rotating antenna 34. As shown in FIG. 4, the rotating antenna 34 has an opening 34 a that passes through the field of view of the infrared temperature sensor 60. In addition to the opening 34a, the rotating antenna 34 has a smaller opening 34b and a notch 34c. The openings 34b and the notches 34c are for distributing high frequencies in a predetermined pattern. Incidentally, the rotation antenna 34 is configured to always be stopped at a position where the opening 34 a overlaps the visual field of the infrared temperature sensor 60 when the rotation is stopped from the rotation state.

  The control system of the high frequency cooking device 1 has a configuration shown in FIG. A control device 70 that controls the entire high-frequency cooking device 1 is configured with a microcomputer as a core, receives output signals from various components, and outputs control signals to various components.

  The components that output a signal to the control device 70 include the operation unit 16 (excluding the display unit 16d), the temperature sensor 24, the infrared temperature sensor 60, and the humidity sensor 71 as well as the following. That is, the door opening / closing sensor 11a that detects whether the door 11 is open or closed, the water level sensor 50a that measures the water level in the steam generator 50, and the water level in the water supply tank 54 are measured. This is a tank water level sensor 54a.

  Constituent elements that operate in response to a control signal from the control device 30 include the display unit 16d, the air supply fan 22, the exhaust dilution fan 23, the antenna motor 35, the cooling fan 39, the convection motor 43, the convection heater 44, and steam. In addition to the generation heater 52, the feed water pump 53, and the high frequency drive power supply 71, a steam temperature raising heater 73 provided separately from the steam generation heater 52 is included in the steam generation device 50.

  Then, operation | movement of the high frequency cooking apparatus 1 is demonstrated. First, the door 11 is opened, and the food that is to be heated is placed in the heating chamber 20. And the door 15 is closed, cooking mode and other conditions are input by the operation part 16, and cooking is started.

  In the high frequency heating mode, the high frequency driving power source 72, the antenna motor 35, the air supply fan 22, the cooling fan 39, and the exhaust dilution fan 23 are turned on. A high frequency is generated when the high frequency drive power source 72 oscillates the magnetron 30, and the generated high frequency enters the antenna chamber 32 through the waveguide 31. The high frequency that has entered the antenna chamber 32 is received by the antenna 34 and then radiated to the heating chamber 20 through the bottom tray 33. And the foodstuff in the heating chamber 20 is heated. When the supply fan 22 supplies fresh air to the heating chamber 20, the air in the heating chamber 20 containing steam generated from food is pushed out to the exhaust duct 22 and diluted by the action of the exhaust dilution fan 23. Then, it is discharged out of the machine through the air outlet 22a.

  In the hot air heating mode, the convection motor 43 and the convection heater 44 are turned on while the supply fan 22 is OFF and the exhaust dilution fan 23 is ON. The convection fan 42 rotated by the convection motor 43 sucks the air inside the heating chamber 20 from the air supply port 45 and discharges it in the outer circumferential direction. The air discharged from the convection fan 42 is heated by the convection heater 44 to become hot air, and is blown out into the heating chamber 20 from the blast port 46 to heat the food in the heating chamber 20. In this case as well, by the operation of the exhaust dilution fan 23, oily smoke, odor, steam and the like generated from the food are sucked into the exhaust duct 22, diluted, and then discharged out of the machine through the outlet 22a.

  In the steam heating mode, with the air supply fan 22 turned off and the exhaust dilution fan 23 turned on, water is poured into the housing 51 of the steam generator 50 to a predetermined water level, and the heater is turned on. When only the steam generating heater 52 is ON, saturated steam is ejected from the steam ejection port 55 into the heating chamber 20. When the steam heating heater 73 is also ON in addition to the steam generating heater 52, superheated steam is ejected from the steam outlet 55 into the heating chamber 20.

  When saturated steam or superheated steam is injected into the heating chamber 20, excess steam in the heating chamber 20 is discharged to the exhaust duct 22. This steam is diluted by the action of the exhaust dilution fan 23, becomes safe at a lower temperature, and further, after the relative humidity is lowered and it becomes difficult to condense on the surrounding walls, it is discharged out of the machine as exhaust from the air outlet 22a. . Since the air in the heating chamber 20 is replaced with steam and the inside of the heating chamber 20 is in a low oxygen concentration state, it is possible to prevent a deterioration in taste due to oxidation.

  The high-frequency heating mode, the hot air heating mode, and the steam heating mode can be executed independently, or two or three of them can be executed simultaneously. In addition, when the food after cooking is cooled, the air supply fan 22 and the exhaust dilution fan 23 may be operated simultaneously to forcibly replace the air in the heating chamber 20.

  As described above, the food is normally cooked while being supported by the tray or rack supported by the upper tray receiver 25 or the lower tray receiver 26. However, there are times when it is desired to cook the food in a cooking container such as a pan. In such a case, the tray or rack is removed, and then the container C is inserted as shown in FIGS. Usually, the bottom surface of the container C is flat and is in close contact with the bottom tray 33. Usually, since the container C is placed near the center of the bottom tray 33, the container C comes directly above the infrared temperature sensor 60.

  A container C shown in FIGS. 2 and 3 is a pan with a lid, and the food F is put together with the soup B inside. When cooking the food F in a state of being put in the container C with a lid in this way, the hot air heating mode or the steam heating mode is often selected, but when the main body or the lid of the container C is made of a dielectric, Alternatively, when the lid is removed, the high-frequency heating mode can be selected.

  In any cooking mode, when heating is performed, the temperature of the contents of the container C rises, and the temperature of the container C itself also rises. In the bottom tray 33, the temperature of the location where the container C is in contact also rises.

  In the bottom tray 33, the temperature of the place where the container C is in contact is measured by the infrared temperature sensor 60 through the space of the antenna chamber 32. If the measured value is multiplied by the correction coefficient, the temperature of the food F can be known. The correction coefficient should be obtained through experiments. The control device 70 controls the heating so that the temperature of the food F becomes a predetermined temperature set by the operation unit 16.

  In the high-frequency heating mode, the infrared temperature sensor 60 performs temperature measurement while the opening 34a of the rotating antenna 34 passes through the visual field. The opening 34a overlaps the visual field of the infrared temperature sensor 60 in an angle section from line A to line B in FIG.

  As described above, when the rotation antenna 34 reaches the rotation stop state from the rotation state, the rotation part 34 is stopped at a position where the opening 34 a overlaps the visual field of the infrared temperature sensor 60. Therefore, there is no problem in temperature measurement by the infrared temperature sensor 60 even in cooking modes other than the high-frequency heating mode.

  Neither steam generated from the food F nor steam used for steam cooking enter between the bottom surface of the container C and the bottom tray 33. Therefore, the temperature of the container C can be measured without being disturbed by steam. Further, since the distance between the infrared temperature sensor 60 and the bottom tray 33 is constant, the measurement error can be small.

  Since the infrared temperature sensor 60 is cut off from the heating chamber 20 by the bottom tray 33, neither steam, moisture dripping from food nor oily smoke adheres to the infrared temperature sensor 60. For this reason, the temperature measurement of the infrared temperature sensor 60 is stabilized. Since the bottom tray 33 protects the infrared temperature sensor 60 from hot air, the infrared temperature sensor 60 is not required to have heat resistance.

  Gas in the heating chamber 20 does not leak through the through hole 32a, and external air does not enter the heating chamber 20 through the through hole 32a. For this reason, the low oxygen cooking performed by filling the inside of the heating chamber 20 with steam is possible.

  The through hole 32a is sized to prevent leakage of high frequency from the antenna chamber 32. Since the infrared temperature sensor 60 is disposed outside the through hole 32a, the infrared temperature sensor 60 may be damaged by high frequency. Absent. However, if the infrared temperature sensor 60 has a structure that is not damaged by high frequencies, a recess is formed in the bottom of the antenna chamber 32 without being placed outside the antenna chamber 32, and the infrared temperature sensor 60 is formed therein. It is also possible to store the battery.

  When the container C is a container that pressurizes or depressurizes, it is difficult to measure the internal temperature with a normal high-frequency cooking apparatus. Even if the sealing degree of C is high, the internal temperature can be measured without making it a problem.

  If the bottom of the container C is formed of a material having high thermal conductivity such as aluminum, temperature measurement with high accuracy can be performed.

  It is also possible to place food on a cooking dish and place the dish on the bottom tray 33. Also in this case, if the dish is formed of a material having high thermal conductivity such as aluminum, temperature measurement with high accuracy can be performed.

  The food can be directly placed on the bottom tray 33 for cooking without using a cooking container or dish.

  What added the modification as follows can also be made into embodiment of the high frequency cooking apparatus 1. FIG.

  The bottom tray 33 can be marked at a temperature detection position by the infrared temperature sensor 60. It is convenient for the user to place a container, a dish, or the food itself so that the mark is hidden. The mark can be formed by various methods such as printing, engraving or positive marking applied to the injection mold of the bottom tray 33, and sticking of a seal.

The bottom tray 33 can be subjected to water repellent treatment at least at a temperature detection position by the infrared temperature sensor 60. This makes it difficult for moisture and dirt to adhere to the temperature detection position by the infrared temperature sensor 60, thereby preventing the measurement accuracy of the infrared temperature sensor 60 from being lowered. The water repellent treatment can be performed, for example, by coating with a fluororesin (polytetrafluoroethylene).

  The bottom tray 33 can be inclined at least at a temperature detection position by the infrared temperature sensor 60. Thereby, since it becomes difficult for a liquid to accumulate in the temperature detection position by the infrared temperature sensor 60, the measurement accuracy of the infrared temperature sensor 60 can be maintained.

  The bottom tray 33 can form the temperature detection position by the infrared temperature sensor 60 higher than the surroundings. Thereby, the temperature detection position by the infrared temperature sensor 60 comes into close contact with an object (container, dish, food) placed on the bottom tray 33, and the entry of steam can be reliably prevented.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention can be widely used for high-frequency cooking apparatuses.

DESCRIPTION OF SYMBOLS 1 High frequency cooking apparatus 10 Case 11 Door 20 Heating chamber 30 Magnetron 31 Waveguide 32 Antenna chamber 32a Through-hole 33 Bottom tray 34 Rotating antenna 34a Opening 40 Convection heater unit 50 Steam generator 60 Infrared temperature sensor 70 Controller

Claims (9)

In a high-frequency cooking apparatus equipped with a cooking mode for introducing steam into the heating chamber,
A dielectric bottom tray is fitted in the bottom of the heating chamber, and the bottom tray is configured as an antenna chamber into which high frequency is introduced, and an object placed on the bottom tray through the space of the antenna chamber An infrared temperature sensor for measuring the temperature of the food is disposed.   The high-frequency cooking apparatus according to claim 1, wherein the infrared temperature sensor is disposed outside the antenna chamber and measures temperature through a through hole formed in a bottom portion of the antenna chamber.   The high frequency cooking apparatus according to claim 2, wherein the through hole is of a size that prevents leakage of high frequency.   The high-frequency cooking apparatus according to any one of claims 1 to 3, wherein an opening that passes through a field of view of the infrared temperature sensor is formed in the rotating antenna disposed in the antenna chamber.   The high-frequency cooking apparatus according to claim 4, wherein the rotation antenna is in a rotation stop state at a position where the opening overlaps the visual field of the infrared temperature sensor.   The high frequency cooking apparatus according to any one of claims 1 to 5, wherein the bottom tray is marked with a temperature detection position by the infrared temperature sensor.   The high-frequency cooking apparatus according to any one of claims 1 to 6, wherein the bottom tray is subjected to water repellent treatment at least at a temperature detection position by the infrared temperature sensor.   The high-frequency cooking apparatus according to any one of claims 1 to 7, wherein the bottom tray is inclined at least at a temperature detection position by the infrared temperature sensor.   The high-frequency cooking apparatus according to any one of claims 1 to 7, wherein the bottom tray is formed such that a temperature detection position by the infrared temperature sensor is higher than the surroundings.

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