CN102265092B - Microwave cooking device - Google Patents

Abstract

A microwave heating cooker comprising: a heating chamber (34) in which a glass door (31b) is opened on the front surface and accommodates an object to be heated; microwaves from a microwave generating part (32) are transmitted to the heating chamber The waveguide (33) of (34); the directional power supply part (39) that has directivity and supplies microwaves from the waveguide (33) to the heating chamber (34); the driving part that drives the directional power supply part (39) to rotate (41); and control the driving part (41) so that the directional power supply part (39) faces the direction of the door and uses the inside of the glass as the main transmission path to supply the control part (411) of the microwave to the space above the tray, the microwave heating and cooking The appliance can automatically and continuously perform the defrosting function and the grilling function without user's operation.

Description

Microwave heating cooker

technical field

The invention relates to a microwave heating cooker for inductively heating an object to be heated.

Background technique

A microwave oven, which is a typical microwave heating cooker, has become an indispensable cooking utensil in daily life because of its simplicity of being able to directly heat food as an object to be heated without preparing a pot or a rice cooker. In recent years, the following products have been put into practical use. In order to heat multiple tableware side by side, the bottom surface of the heating chamber for storing food is formed flat, and the width dimension is 400mm or more and larger than the depth dimension, so that it has a horizontal width. Heating chamber of wide and convenient shape.

In addition, with the multifunctionalization of microwave ovens, products with so-called "grilling functions" and "thawing functions" have appeared on the market. "Grilling function" refers to the function of heating and cooking the food placed on it by using a so-called heating plate provided with a microwave absorber such as ferrite on the lower surface that absorbs microwaves and heats up the heating plate. . In addition, the "thawing function" refers to a function of thawing frozen foods by heating with microwaves, or steam, or a combination of both.

Referring to Fig. 14, the conventional microwave heating cooker 300 described above will be described. The microwave heating cooker 300 includes: a magnetron 302, a waveguide 303, a heating chamber 301, a mounting table 306, a power supply part (antenna space) 310, a rotating antenna 305, a motor 304, a heating plate 308, a plate holder 307, and a heater 309.

The magnetron 302 is a representative microwave generating device. The waveguide 303 transmits the microwave emitted by the magnetron 302 to the heating chamber 301 . In the heating chamber 301, objects to be heated such as food (not shown) are placed therein, and are used for heating operations by microwaves. The mounting table 306 is made of a low-loss induction material such as ceramics or glass that can easily transmit microwaves. The mounting table 306 is fixed in the heating chamber 301 and is used for mounting a heating object.

The feeding unit 310 is an antenna space formed below the mounting table 306 in the heating chamber 301 . In order to radiate microwaves in waveguide 303 into heating chamber 301 , rotating antenna 305 is installed near the center of heating chamber 301 in a range from waveguide 303 to feeding unit 310 . The motor 304 drives the rotating antenna 305 to rotate. The heating pan 308 is installed in the heating chamber 301 according to the application, and the pan holder 307 supports the heating pan 308 . The heater 309 performs electrothermal heating.

When performing the heating function of directly heating the object to be heated by microwave heating, the microwave heating process is started with the food or the like placed on the mounting table 306 . The microwaves radiated from the magnetron 302 are radiated toward the heating chamber 301 from the upper surface of the radiation portion of the rotating antenna 305 via the waveguide 303 and the rotating antenna 305 . At this time, in general, the rotating antenna 305 radiates microwaves while rotating at a constant speed in order to uniformly stir the microwaves in the heating chamber 301 (for example, refer to Patent Document 1).

When performing the thawing function of heating frozen food as an object to be heated by microwave heating, first place the frozen food on a heat-resistant tray or flat plate, and place the tray or flat plate in this state on the mounting table 306 . Then, select the defrosting function to start the operation of the microwave heating cooker. The defrosting operation ends when the object to be heated reaches a predetermined temperature or when the operation has been performed for a set time (for example, refer to Patent Document 2).

When performing the grilling function of direct-fire grilling cooking, food (such as chicken legs, fish, etc.) is placed on the heating plate 308 , and the heating plate 308 is placed on the plate holder 307 . In this state, the surface portion of the food is heat-treated by the heater 309 located above the food. On the other hand, the back surface of the food is heat-treated by the heating pan 308 that absorbs microwaves and heats up.

In addition, the microwave heating cooker 300 may be provided with a plurality of substantially rectangular openings, namely narrow holes, provided around the heating pan main body in addition to the above-mentioned structure, and may be detachably attached to the narrow holes. In the above-mentioned method, a slit-hole closing member formed of rubber containing ferrite as a main component is provided (for example, refer to Patent Document 3).

In this microwave heating cooker equipped with narrow holes, when performing the defrosting function of heating frozen food as an object to be heated, the frozen food is placed on a heat-resistant tray or flat plate, and the tray or flat plate is placed The disk is placed on the mounting table 306 . Then, the slit sealing member is removed to open the slit, a menu is selected, and the operation of the microwave heating cooker is started. When the object to be heated reaches the predetermined temperature, or the operation has been carried out for the set time, the defrosting operation ends.

However, in the conventional microwave heating cooker described in the above-mentioned Patent Document 2, when using the grilling function to cook frozen food, it is necessary to perform further menu setting after performing the above-mentioned thawing function, and then execute the grilling function. For this reason, the heating plate 308 having the food after thawing has to be placed on the predetermined plate holder 307 again after the thawing is completed, and the grilling function is performed again, forcing the user to perform complicated operations.

Therefore, if the heating pan 308 is set in the heating chamber 301 initially, if the thawing function and the grilling function are continuously performed on the frozen food, the expected effect cannot be obtained through the installed heating pan 308 . That is, since there is almost no gap between the peripheral portion of the heating pan 308 and the inner wall of the heating chamber 301, the microwaves uniformly radiated to the heating chamber 301 from the power supply unit 310 (rotating antenna 305) are shielded by the lower surface of the heating pan 308, It is impossible to go around to the upper surface side of the heating plate 308 .

In addition, when using the conventional microwave heating cooker described in the above-mentioned Patent Document 3 for cooking frozen food, it is necessary to perform menu setting again after performing the defrosting function, and then perform the grilling function. For this reason, it is necessary to assemble a narrow hole closing member to close the narrow hole after the thawing is completed, reset the heating plate with the thawed food on the predetermined plate holder and perform the grilling function, or force the user to perform complicated operations .

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2004-071216

Patent Document 2: Japanese Patent Application Laid-Open No. 09-229372

Patent Document 3: Japanese Patent Laid-Open No. 2007-225186

Contents of the invention

The present invention provides a microwave heating cooker capable of automatically and continuously performing a defrosting function and a grilling function without user's operation even when a heating pan on which an object to be heated is placed is installed in a heating chamber.

The structure of the present invention includes: a heating chamber with a glass door installed at the opening of the front surface, the heating chamber accommodates the object to be heated; a microwave-permeable mounting table, the mounting table constitutes the heating chamber The bottom surface of the metal heating plate, the heating plate is provided with a microwave absorber on the lower surface, the heating plate is detachably assembled in the heating chamber, and the heating plate carries the object to be heated; the microwave generating part; the waveguide tube, the waveguide transmits the microwave from the microwave generating part to the heating chamber; a directional power supply part, the directional power supply part has directionality, and supplies the microwave the heating chamber; a driving part, the driving part drives the directional power supply part to rotate; a control part, the control part controls the driving part so that the directional power supply part faces the direction of the door, and The interior of the glass serves as a main transmission path for supplying microwaves to a space above the heating plate; and a power supply part formed below the mounting table and accommodates the directional power supply part .

According to the above configuration, the inside of the door can be used as a microwave transmission path without using additional components or processing existing components. That is, without complicating the structure, it is possible to efficiently use the dead space to increase the amount of the microwaves going around the heating plate. Thereby, desired cooking according to the type of the object to be heated, such as thawing by directly absorbing microwaves, can be performed, and heating efficiency can be improved. Therefore, when the heating pan on which the object to be heated is placed is installed in the heating chamber, the defrosting function and the grilling function can be automatically and continuously performed without user's operation.

Description of drawings

FIG. 1 is a front cross-sectional view showing an internal structure of a microwave oven as a microwave heating cooker according to an embodiment of the present invention.

FIG. 2 is a diagram showing a 2-2 section of the microwave oven in FIG. 1 .

3A is a 3-3 cross-sectional view of the microwave oven in FIG. 1 for explaining the orientation of the rotating waveguide in this embodiment.

3B is another 3-3 sectional view in FIG. 1 for explaining the orientation of the rotary waveguide of the microwave oven in this embodiment.

3C is still another 3-3 sectional view in FIG. 1 for explaining the orientation of the rotary waveguide of the microwave oven in this embodiment.

FIG. 4 is an explanatory diagram of an origin detection mechanism of the rotary waveguide of the microwave oven according to the present embodiment.

FIG. 5 is a configuration diagram showing the configuration of a control unit of the microwave oven according to the present embodiment.

FIG. 6 is a flowchart showing the operation of the microwave oven in this embodiment.

FIG. 7 is a diagram showing the configuration of a temperature detector employed in the microwave oven according to the present embodiment.

Fig. 8 is a plan view showing a modified example of the rotary waveguide of the microwave oven according to the present embodiment.

Fig. 9A is a plan view illustrating a heating plate of the microwave oven according to the present embodiment.

Fig. 9B is a side view illustrating a heating plate of the microwave oven according to the present embodiment.

9C is a cross-sectional view taken along line 9C-9C in FIG. 9A illustrating the heating plate of the microwave oven according to the present embodiment.

10A is an explanatory view of the orientation of the opening of the rotary waveguide of the microwave oven with respect to the heating plate and the routing of microwaves to the upper surface side of the heating plate in the microwave oven according to the present embodiment.

10B is another explanatory view of the orientation of the opening of the rotary waveguide of the microwave oven with respect to the heating plate and the routing of microwaves to the upper surface side of the heating plate in the microwave oven according to the present embodiment.

11A is an explanatory diagram of a method of checking the amount of microwaves reaching the heating plate in the microwave oven according to the present embodiment.

FIG. 11B is another explanatory diagram of a method of confirming the amount of microwaves reaching the heating plate in the microwave oven according to the present embodiment.

11C is still another explanatory diagram of the confirmation method of the amount of microwave reaching the heating plate of the microwave oven in this embodiment.

FIG. 12A is an explanatory diagram of the relationship between the orientation of the opening of the rotary waveguide of the microwave oven with respect to the heating plate and the amount of microwave circumvention in the microwave oven according to the present embodiment.

12B is another explanatory diagram of the relationship between the orientation of the opening of the rotary waveguide of the microwave oven with respect to the heating plate and the amount of microwave arrival in the microwave oven according to the present embodiment.

Fig. 13 is a diagram showing the relationship shown in Fig. 12B.

Fig. 14 is a front sectional view showing the internal structure of a conventional microwave oven.

Detailed ways

(implementation mode)

Next, the microwave heating cooker according to the embodiment of the present invention will be described using a microwave oven as an example with reference to FIGS. 1 to 13 .

As shown in FIGS. 1 and 2 , the microwave oven 31 has a door 31b attached to a main body 31a. The main body 31a is built with: a heating chamber 34, which accommodates heated objects such as food; a magnetron 32, which generates microwaves for heating and cooking the heated object; It is connected with the magnetron 32. A front opening 38 is formed on the front surface of the heating chamber 34 .

The door 31b is attached to the main body 31a, and is comprised so that it may open and close freely and cover the front surface opening 38 formed in the heating chamber 34. As shown in FIG. The door 31b may be mounted on the main body 31a via a hinge, or in a sliding manner such as a sliding door. In the case where the microwave oven 31 is a built-in type, the door 31b may be attached to the main body 31a in a manner of being pulled out. In the case of attaching via a hinge, it may be attached to any one of the left side, right side, or lower side of the front opening 38 .

The door 31b includes: a metal plate 60; an inner glass 61 and an outer glass 62 sandwiching the metal plate 60 from the front and rear directions; and a choke cover (not shown) covering the outer periphery of the metal plate 60. A plurality of through-holes are formed at positions facing the front opening 38 of the metal plate 60 so that the inside of the heating chamber 34 can be visually recognized. A blocking structure 63 is formed on the outer peripheral portion of the metal plate 60 .

In FIG. 2 , the case where the blocking structure 63 is formed by bending the metal plate 60 a plurality of times is shown as an example. In addition, it is preferable that the blocking structure 63 is formed by bending the comb-shaped end portion a plurality of times with a plurality of slits formed at the end of the metal plate 60 at predetermined intervals. In the case of forming the blocking structure 63 in a comb shape, the number of slits is not particularly limited.

The inside glass 61 functions as one surface constituting the heating chamber 34 in a state where the door 31b is closed. The inside glass 61 enables the inside of the heating chamber 34 to be visually recognized in a state where the door 31b is closed. The outer glass 62 functions to constitute the outer surface of the door 31b. Like the inner glass 61, the outer glass 62 enables the heating chamber 34 to be visually recognized in a state where the door 31b is closed.

The microwave oven 31 includes a mounting table 35 , a power supply unit (antenna space) 37 , a rotary waveguide 39 , a motor 41 , a control unit 411 , and a photo interrupter (photo interrupter) 36 . In addition, the heating chamber 34 is connected to the upper part of the waveguide 33, and the heating chamber 34 is formed as a space whose width direction dimension (approximately 400 mm) is larger than the depth direction dimension (approximately 310 mm). The mounting table 35 is made of a low-loss induction material such as ceramics or glass that can easily transmit microwaves, and the mounting table 35 is fixed in the heating chamber 34 to place food (not shown) as a representative object to be heated. .

The power supply unit 37 is formed below the mounting table 35 in the heating chamber 34 . The rotating waveguide 39 is installed in the power supply unit 37 and radiates the microwaves in the waveguide 33 into the heating chamber 34 . The motor 41 is a drive unit that drives the rotary waveguide 39 to rotate. The control unit 411 is a control unit that controls the motor 41 to control the rotation and orientation of the rotary waveguide 39 . The photo-interrupter 36 constitutes origin detection means for detecting the origin of rotation of each rotating waveguide 39 .

In addition, the rotating waveguide 39 is a directional power feeding part which has the opening 58 shown in FIGS. 3A to 3C and can radiate microwaves intensively in the direction in which the opening 58 faces.

Returning to FIG. 1 , a heater 401 capable of electrothermal heating is provided on the upper surface of the heating chamber 34 . In addition, the heating chamber 34 has three layers of pan holders that support the heating pan 402 . Specifically, the heating chamber 34 has an upper disk holder 403 , a middle disk holder 404 , and a lower disk holder 405 . In addition, the upper disk holder 403 , the middle disk holder 404 , and the lower disk holder 405 are collectively referred to as the disk holder 400 .

The heating plate 402 will be described with reference to FIGS. 9A to 9C . FIG. 9A shows a top view of the heating plate 402 viewed from above. FIG. 9B shows a side view of the heating plate 402 viewed from the side. Figure 9C shows a cross-sectional view along line 9C-9C in Figure 9A. The heating plate 402 is composed of: a frame-shaped peripheral portion 402a; and a plate 402c formed inside the peripheral portion 402a, and a plurality of grooves 402b of a predetermined depth are formed side by side on the plate 402c (not shown in FIG. 9C ). ). The object to be heated is placed on the plate 402 c and placed in the heating chamber 34 . In addition, a microwave absorber 406 (for example, ferrite) is provided on the back side of the plate (the side closer to the mounting table 35 ).

As shown in FIG. 5, the operation part 31c is arrange|positioned at the front surface lower part of the door 31b. The operation unit 31c is a device through which the user can select various cooking menus according to foods and cooking contents. For example, the heating time can be set through the operation part 31c, and preset automatic cooking menus such as "heating function", "thawing function", "thawing and grilling function" and "grilling function" can be selected.

"Heating function" refers to a cooking method that heats food by radiating microwaves to food. "Defrosting function" refers to the heating method of frozen food using the following methods: the method of heating frozen food by continuously or intermittently radiating microwaves, or the method of thawing frozen food by heating with steam, or using A combination of the above methods to defrost food.

"Thawing and grilling function" refers to making the opening 58 of the rotating waveguide 39 face the direction that is easy to reach the upper surface of the heating plate, that is, the direction of the front surface opening 38 of the heating chamber 34, or towards the edge of the heating plate 402 and the heating chamber. In any direction of the gap between the inner walls of 34, after the frozen food placed on the heating plate 402 absorbs microwaves and thaws, the thawed food is then cooked by the "grilling function" described later. In the present embodiment, the open portion 58 of the rotating waveguide 39 faces the front opening 38 of the heating chamber 34, and a heating plate upper surface heating mode in which the supply amount of microwaves to the upper surface of the heating plate 402 is large is implemented to make the carrier After the frozen food placed on the heating plate 402 absorbs microwaves and thaws, the thawed food is then cooked by the "grilling function" described later.

The "grilling function" refers to concentrating microwaves on the microwave absorber 406 on the rear side of the heating pan 402 on which food is placed to generate heat at a high temperature. It refers to a cooking method of heating food through the heating plate 402 and a cooking method of heating food by combining the heated heating plate 402 and a heater.

The control section 411 executes these menus by controlling the magnetron 32 and the motor 41 based on the output signal from the operation section 31c.

In the microwave oven 31 according to this embodiment, the opening portion 58, which is the part with strong radiation directionality of the rotary waveguide 39, is controlled to a predetermined orientation, and especially in the “thawing and grilling function”, the microwave is increased to the heating plate 402 in the first half. The amount of winding on the upper surface is used to defrost efficiently. In addition, microwaves are concentrated on the microwave absorber 406 on the back side of the plate of the heating plate 402 in the second half of the process to efficiently generate heat. The specific control will be described later.

Returning to FIG. 2 , the coupling portion 46 is made of a substantially cylindrical conductive material passing through a substantially circular coupling hole (not shown) provided between the waveguide 33 and the bottom surface 42 of the heating chamber. interface. The radiation part 48 is made of a conductive material whose area in the horizontal direction is larger than that in the substantially vertical direction, and is electrically connected to the upper end of the coupling part 46 by caulking or welding to be integrated. The rotating waveguide 39 includes a coupling portion 46 and a radiation portion 48 .

In addition, the rotary waveguide 39 is fitted to the shaft 50 of the motor 41 so that the center of the coupling portion 46 is the center of the rotational drive. Since the shape of the radiation part 48 is not fixed with respect to the direction of rotation, it is configured to have radiation directivity. The center of rotation of the rotating waveguide 39 is arranged at the center of the heating chamber 34 .

As shown in FIGS. 3A to 3C , the radiating portion 48 is configured such that, viewed from above, the radiating portion upper surface 52 is formed into a trapezoidal shape with the side of the open portion 58 as the base. The other three sides have radiation portion curved portions 54 bent toward the bottom surface 42 ( FIG. 1 ) of the heating chamber so as to limit the radiation of microwaves from the three sides to the outside.

In this structure, when general food is uniformly heated by the "heating function", the rotary waveguide 39 can be constantly rotated as in the conventional one without being particularly particular about the place of placement, as in conventional microwave ovens. In addition, when it is possible to heat uniformly by stopping at an angle in the middle of the rotation, it may be stopped. In this embodiment, it is a constant rotation.

In the case of using the "defrosting function" to heat the frozen food placed on the mounting table 35 in the heating chamber 34, the rotating waveguide 39 can be rotated and stopped at predetermined time intervals, and when the constant rotation is more uniform Constant rotation is also possible while heating. In this embodiment, it is a constant rotation.

When using the “thawing and grilling function” to heat and cook frozen food, the operation starts with the heating pan 402 on which the frozen food is placed on a predetermined pan holder 400 , for example, the upper pan holder 403 . The opening 58 of the rotating waveguide 39 faces the front opening 38 of the heating chamber 34, and the microwave reaches the top of the heating plate 402 through the inner glass 61 of the door 31b, and the frozen food placed on the heating plate 402 is thawed. Use the grill function for heat cooking.

When using the "grilling function" to heat food placed on the heating plate 402, in the state where the opening part 58 of the rotating waveguide 39 faces a predetermined position (for example, a different direction from the front surface opening 38), the The operation of the rotating waveguide 39 stops, or it may rotate constantly.

A predetermined stop position of the rotating waveguide 39 will be described with reference to FIGS. 3A to 3C . In microwave oven 31 according to the present embodiment, control unit 41 stores angle information (stop position) of rotating waveguide 39 based on the origin detected by the origin detection mechanism having photo-interrupter 36 . The state where the opening portion 58 of the rotating waveguide 39 shown in FIG. 3A faces the door 31b is defined as 180°, and the state where it faces backward (not shown) is defined as the origin position (0°).

In the direction shown in FIG. 3A , microwaves are intensively radiated toward the inner glass 61 of the door 31 b. Then, the radiated microwave passes through the gap between the heating pan 402 and the inner glass 61 , the inside of the inner glass 61 , and the space between the inner glass 61 and the metal plate 60 , and reaches above the heating pan 402 . Here, the inner glass 61 is a dielectric body for the microwaves propagating inside the inner glass 61 , and the wavelength of the microwaves propagating through the dielectric body is shortened to the reciprocal multiple of the square root of the dielectric constant of the dielectric body. Accordingly, in the case of glass having a dielectric constant of 4 to 9, it is equivalent to having a space gap approximately 2 to 3 times the plate thickness of the glass. Therefore, most of the microwaves radiated to the inner glass 61 side can go around and reach above the heating plate 402 by utilizing the large gap. On the other hand, the orientation of the rotating waveguide 39 suitable for the "grilling function" is not uniform, but should at least be different from the orientation towards the door 31b. Therefore, it is conceivable to obtain an appropriate orientation through experiments in advance and store it in the control unit 411 .

For example, as shown in FIG. 3B , when the opening portion 58 of the rotating waveguide 39 is directed toward the right side of the heating chamber 34 with respect to the direction of the door 31b, the microwaves obtained are concentrated on the heating disk 402 placed on the upper disk holder 403. Thus, in the case of efficiently heating up the heating pan 402, this position (for example, rotated clockwise by 130° from the origin) is used as the "grilling function" when the heating pan 402 is placed on the upper tray holder 403. The stop position of the rotating waveguide 39 is stored in the control unit 411 .

Next, for the "grilling function" when the heating plate 402 is placed on the middle plate holder 404, for example, as shown in FIG. In the case where microwaves are concentrated on the heating pan 402 to efficiently heat the heating pan 402, this position (for example, rotated 230° clockwise from the origin) is used as the position where the heating pan 402 is placed on the middle tray holder 404. The stop position of the rotating waveguide 39 during the "grill function" is stored in the control unit 411.

As described above, the microwave oven 31 controls the orientation of the rotating waveguide 39 according to the position of the hot plate 402 . In order to orient the rotating waveguide 39 in a predetermined direction, a stepping motor is used as the motor 41, or a method such as detecting a reference position and controlling the energization time is conceivable for a constant rotation motor.

Referring to Fig. 4, the origin detection mechanism will be described. In this embodiment, an origin detection mechanism is provided on the shaft 50 of the stepping motor used as the motor 41 . The origin detection mechanism is composed of a circular plate 36 a centered on the axis 50 and a photo-interrupter 36 . A rectangular slit 36b is provided in the circular plate 36a.

The disc 36a is attached to the shaft portion of the shaft 50 of the motor 41 that rotates the rotary waveguide 39, and rotates so as to block the optical path of the photo-interrupter 36 including the light emitting element and the light receiving element.

According to this configuration, when the slit 36 b passes through the optical path of the photo-interrupter 36 , there is nothing blocking the optical path, so the passing timing of the slit 36 b can be detected. Therefore, by setting the position of the slit 36 b as the origin of the rotating waveguide 39 , the origin of the rotating waveguide 39 can be detected by the photo-interrupter 36 attached to each motor 41 .

Next, the control unit 411 will be described with reference to FIG. 5 . The control unit 411 includes an antenna control unit 412 and a storage unit 413 . The antenna control unit 412 controls the operation of the rotary waveguide 39 by controlling the operation of the motor 41 . The storage unit 413 stores position information (angle information) of the rotating waveguide 39 .

The antenna control unit 412 controls the motor 41 by referring to necessary information from the storage unit 413 based on the command signal from the operation unit 31c, thereby controlling the operation of the rotary waveguide 39 . The storage unit 413 stores the position information of the rotating waveguide 39 suitable for thawing and the rotating waveguide 39 suitable for heating the heating disk 402 for each placement position (upper layer, middle layer, lower layer) of the heating disk 402 in the heating chamber 34 location information. Specifically, the location information 414 for thawing on the upper layer (as the origin rotates 180° clockwise), the location information 415 for grilling on the upper layer (rotating 130° clockwise from the origin), and the grilling location information 415 for the middle layer The position information 416 (rotated 230° clockwise from the origin) and the like.

Next, the operation of microwave oven 31 according to the present embodiment will be specifically described with reference to FIG. 6 . First, the microwave oven 31 is powered on, and in step S102, it enters a standby state.

In step S102, it is in the acceptance state which accepts the selection of the menu by the user using the operation part 31c. Specifically, the operation unit 31c outputs the menu signal Sm corresponding to the menu selection selected by the user to the control unit 411 . In this embodiment, the user selects "heating function", "thawing and grilling function", "grilling function" or other menus according to the content of the object to be heated (type of food). In addition, the position (upper, middle, or lower) where the heating pan 402 is placed is also included in the menu.

When it is determined that the "heating function" has been selected, the operation unit 31c outputs a menu signal SmA indicating the "heating function" to the antenna control unit 412 . Then, control proceeds to step S103.

In step S103 , the antenna control unit 412 rotates the rotary waveguide 39 at a constant speed by rotating the motor 41 at a constant speed in response to the menu signal SmA. Then, control proceeds to the following step S104.

In step S104, the control part 411 operates the magnetron 32, and starts heat processing. Then, control proceeds to the following step S105.

In step S105, the timer starts counting. After confirming that the first predetermined period P1 has elapsed, the control proceeds to the following step S106.

In step S106, the operation|movement of the magnetron 32 etc. is stopped, and the heating process by a "heating function" is complete|finished.

When the "thawing and grilling function" is selected in step S102, the operation unit 31c outputs a menu signal SmB indicating that the "thawing and grilling function" is selected to the antenna control unit 412. Then, control proceeds to the following step S107.

In step S107 , antenna control unit 412 judges based on menu signal SmB whether or not the position where heating plate 402 is placed is the upper stage. In addition, the "thawing and grilling function" is formed to be able to select types such as meat, fish, and pizza. Then, control proceeds to the following step S108.

In step S108 , the antenna control unit 412 controls the operation of the motor 41 based on the position information determined in step S107 and refers to the corresponding position information from the storage unit 413 . Specifically, the antenna control unit 412 refers to the position information 416 in the storage unit 413 based on the position information in the menu signal Sm determined in step S107. Thus, the antenna control unit 412 controls the operation of the motor 41 so that the rotating waveguide 39 rotates and stops in a direction in which microwaves easily reach the upper surface of the heating plate 402 , for example, in the direction of the front opening 38 (180°). Then, control proceeds to the following step S109.

In step S109, the control part 411 operates the magnetron 32, and starts a heating process, with the rotating waveguide 39 stopped at the predetermined position controlled by S108. Then, control proceeds to the following step S110.

In step S110, after a predetermined stop time elapses, the rotating waveguide 39 is rotated once again, and then stops at 180° for a predetermined time. In this way, the rotation and 180° stop are repeated. Then, control proceeds to the following step S111.

In step S111, the timer starts counting. After confirming that the second predetermined period P2 has elapsed, the control proceeds to the following step S112. During this period, since the microwave is likely to go around and reach the upper side of the heating plate, the food can be thawed efficiently.

In step S112, it is judged whether the defrosting is finished. When thawing is not finished (NO in S112), then thawing is continued, and it is judged in step S112 whether thawing is finished. Repeat this process until thawing is complete. When thawing is completed (YES in S112), since thawing is complete|finished, it progresses to step S113 in order to transfer to "grill function" next. Thereafter, in order to grill the food, it should be transferred to the "grill function", which is the same as the case where the "grill function" is selected in the above-mentioned step S102 (that is, the case of grilling the food that has not been frozen). Can.

In step S102 , when the “grill function” is selected, the operation unit 31 c outputs a menu signal SmC indicating that the “grill function” is selected to the antenna control unit 412 . Then, control proceeds to the following step S113. In addition, the above-mentioned menu signals SmA, SmB and this menu signal SmC are collectively referred to as a menu signal Sm.

In step S113 , the antenna control unit 412 judges based on the menu signal SmC whether the position where the heating plate 402 is placed is the upper level, the middle level, or the lower level. In addition, the "grill function" is configured to be able to select the type of food to be grilled, such as fish, chicken leg, roast beef, roast chicken, pizza, and paella. Corresponding to the type of food to be grilled, the positions of the trays are stored in advance as upper, middle, and lower, and the position of the tray is determined by selecting the type of food to be grilled using the "grill function". However, the present invention is not limited thereto. For example, detectors may be provided in each of the disk holders 403 to 405, and disk positions may be determined based on signals from the detectors. Then, control proceeds to the following step S114.

In step S114 , the antenna control unit 412 controls the operation of the motor 41 based on the menu signal SmC and refers to the corresponding position information from the storage unit 413 . For example, when the barbecue function is selected on the upper floor through the operation part 31c, the antenna control part 412 refers to the position information 415 for the upper floor, controls the operation of the motor 41, and rotates the rotating waveguide 39 to 130° clockwise from the origin. position and stop there. Then, control proceeds to the following step S115.

In step S115 , the control unit 411 operates the magnetron 32 while the rotating waveguide 39 is stopped, and heat treatment is started. Then, control proceeds to the following step S116. In step S116, after the predetermined stop time of the rotary waveguide 39 has elapsed, the rotary waveguide 39 is rotated once again, and then stopped at 130° for a predetermined time. In this way, the rotation and 130° stop are repeated. Next, proceed to step S117.

In step S117, the timer starts counting, and after confirming that the third predetermined period P3 has elapsed, the control proceeds to the subsequent step S118. During this period, since microwaves are likely to concentrate on the ferrite on the back surface of the heating plate, the temperature of the heating plate is raised and the bottom surface of the food can be efficiently grilled.

In step S118, the magnetron 32 is stopped, and in the subsequent step S119, the heater 401 is driven this time. Next, in subsequent step S120, the timer starts counting, and after confirming that the fourth predetermined period P4 has elapsed, the control proceeds to subsequent step S106. During this period, the upper surface of the food can be efficiently grilled by the heater 401 .

In step S106, after the operations of the rotary waveguide 39, the heater 401, the magnetron 32, and the like are stopped, the heating process of the "grill function" ends.

Through the above structure, the microwave oven 31 according to this embodiment has three layers (upper, middle, and lower) of tray holders 403 to 405 in the heating chamber 34, and can select a cooking menu according to the position of the tray holders, and can use the "grilling function". "Heating and cooking a variety of foods.

For example, the upper layer (pan holder 403 ) is used when preparing conventional grill dishes with ingredients that have no thickness, such as fish and chicken drumsticks. The middle layer (pan support portion 404 ) is used when cooking large ingredients such as roast beef and roast chicken. As for the lower layer (pan supporting part 405), pizza, paella, and the like require backside firepower, but the firepower on the upper surface is relatively mild. Therefore, the cooking performance can be improved by keeping the distance from the upper surface heater.

In addition, ferrite, which is microwave absorber 406 attached to the lower surface of heating pan 402 , absorbs microwaves to generate heat, whereby the lower surface of the cooking item can be baked. In addition, as for the upper surface of the cooking object, the upper surface cooking can be realized by heating with the heater 401 arranged on the upper surface of the heating chamber 34 . In addition, in order to efficiently heat the back surface of the heating pan 402, the stop position of the rotary waveguide 39 of the microwave heating cooker is controlled by the position of the pan holder.

Since the distribution of the microwaves changes depending on the position on which the heating plate 402 is placed, the temporary stop position of the rotary waveguide 39 is different, and the stop position is obtained experimentally as described above and stored in the storage unit 413 . By providing the motor 41 with an origin detection mechanism, the stop position of the rotary waveguide 39 can be accurately controlled, and the most efficient heating can be realized at the positions of the respective disc holders 403 to 405 . In such a "grilling function", microwaves propagating to the upper space of heating pan 402 (the space where food is placed) are reduced, so that excessive evaporation of moisture inside the food can be prevented.

In addition, an example in which the rotating waveguide 39 is stopped when the thawing and grilling function or the grilling function is selected has been described, but the operation control of the rotating waveguide 39 is not limited to this.

For example, the antenna control unit 412 of the control unit 411 may reciprocate the rotating waveguide 39 by approximately a predetermined angle (eg, ±5 degrees) around the target angle (stop position). Thus, the distribution can be made very uniform without affecting the heating efficiency of the heating plate. This reciprocating rocking operation may be performed from the start of heating, or may be started after a predetermined time has elapsed (for example, 30 seconds to 1 minute) from the start of heating.

In order to perform this reciprocating swing action, the control unit 411 is configured to include: a stop upper limit time storage unit, which stores in advance the upper limit time that allows the rotating waveguide 39 to stop; a stop time counting unit, which counts the time when the rotating waveguide 39 stops; And a reciprocating angle storage unit that stores an angle for reciprocating the rotating waveguide 39 .

Alternatively, the rotating waveguide 39 may be rotated by a predetermined angle (eg, 5 degrees) after a predetermined time (eg, 30 seconds to 1 minute) has elapsed from the start of heating when the grilling function is implemented.

In addition, for the same purpose, the rotation speed of the rotating waveguide 39 may also be controlled. For example, the rotating waveguide 39 may be rotated slowly near a predetermined position and rotated at a constant speed at other positions so that the microwaves are concentrated on the heating plate 402 . Also in this case, near which position and at which speed the rotating waveguide is controlled to concentrate the microwaves on the heating plate is experimentally obtained in advance.

In addition, the control unit 411 stores the time when the rotating waveguide 39 is at a predetermined stop position (angle) as the origin. Furthermore, the control unit 411 executes the origin detection mode for checking the origin of the rotating waveguide 39 together with the "heating function" and the "grilling function", for example, before or after the heat treatment.

In the origin detection mode, the angle of the rotating waveguide 39 cannot be specified, and if microwaves are oscillated in this state, an unintentional heating state may occur and cause a defect. Therefore, the control unit 411 performs control to stop the operation of the magnetron while the rotary waveguide 39 is being driven in the origin detection mode.

In addition, the control part 411 performs an origin detection mode after completion|finish of a heat process, and waits in the non-heating time in the state which detected the origin. Thereby, it is possible to prevent generation of a standby time for origin detection before the heat treatment is started.

FIG. 7 shows an example of a temperature detector for detecting temperature distribution. The temperature detector 10 includes an infrared detection element 13 , a housing 18 and a stepping motor 11 . The infrared detection elements 13 are arranged in a row on the substrate 19 , the housing 18 accommodates the entire substrate 19 , and the stepping motor 11 moves the housing 18 in a direction perpendicular to the direction in which the infrared detection elements 13 are arranged.

On the substrate 19 are provided a metal can body 15 in which the infrared detection element 13 is enclosed, and an electronic circuit 20 that processes the operation of the infrared detection element 13 . The can body 15 is provided with a lens 14 through which infrared rays pass. The casing 18 is provided with: an infrared ray passing hole 16 through which infrared rays pass; and a hole 17 through which a lead from the electronic circuit 20 passes.

According to this configuration, the casing 18 can be moved in a direction perpendicular to the direction in which the infrared detection elements 13 are aligned by the rotational movement of the stepping motor 11 . The temperature distribution in substantially all regions in the heating chamber 34 can be detected by the reciprocating rotation operation of the stepping motor 11 of the temperature detector.

The case where there is one rotating waveguide has been described, but the number of rotating waveguides 39 is not limited to this, and may be two or more. For example, as shown in FIG. 8 , two rotating waveguides 90 and 91 may be provided in the width direction of the heating chamber 34 .

In FIG. 8 , the respective openings 92 and 93 of the rotating waveguides 90 and 91 are arranged toward the vicinity of the center in the heating chamber 34 . In this case, it is also possible to obtain in advance through experiments in which positional relationship the two rotating waveguides 90 and 91 are located, the microwaves tend to go around and reach the upper side of the heating plate 402 , or the microwaves are concentrated on the heating plate 402 .

By providing a plurality of rotating waveguides 39, the combination of stop positions of the rotating waveguides 90 and 91 is increased (for example, one rotating waveguide 90 is at the origin position, while the other rotating waveguide 91 is rotated 90 degrees counterclockwise from the origin etc.), microwave-controlled variable width widening. Therefore, it is possible to more efficiently direct the microwaves to reach the upper side of the heating pan 402 or to concentrate the microwaves on the heating pan 402 . As a result, the heating efficiency of defrosting and the heating efficiency of grilling of the "thawing and grilling function" can be improved. On the other hand, it is also possible to intensively heat the area of the left half or the right half, or the upper half or the lower half of the heating plate 402, and the variation of the cooking method is also increased.

In this embodiment, microwaves are radiated into the heating chamber 34 from below the heating chamber 34, but the power supply unit 37 may also be provided above the heating chamber 34, and the microwaves may be radiated from above the heating chamber 34 so that the microwaves reach the heating plate. 402 lower surface.

Next, referring to FIG. 10 , FIG. 10B , FIGS. 11A to 11C and FIGS. 12A and 12B , the relationship between the orientation of the opening 58 of the rotating waveguide 39 relative to the heating plate 402 and the amount of microwaves supplied to the upper surface of the heating plate 402 The relationship between them will be described. FIG. 10A shows a state in which heating pan 402 ( FIG. 9 ) provided in pan holder 400 of heating chamber 34 is viewed from above. FIG. 10B shows a state in which the food placed on the heating pan 402 is heated by microwaves when viewed from the direction of the inner glass 61 of the door 31b. In addition, as shown by wavy lines in FIG. 10A , the rotating waveguide 39 is oriented in the lateral direction of the microwave oven 31 , that is, in a direction parallel to the door 31 b.

As shown in FIG. 10A , there is substantially no gap between the heating pan 402 and the left and right walls of the heating chamber 34 of the microwave oven 31 . Therefore, the microwave MW radiated from the magnetron 32 is approximately perpendicular to the left and right inner walls of the heating chamber 34 through the opening portion 58 of the rotary waveguide 39 and is aligned with the door 31b and the rear wall protrusion 420 (circulation fan unit accommodating portion). Radiate in roughly parallel directions. Therefore, most of the microwaves radiated into the heating chamber 34 are reflected by the left and right side walls of the heating chamber 34 , the pan holder 400 , and the like, and are finally mostly absorbed by the microwave absorber 406 . And the microwave absorber 406 converts into heat, and foodstuff F is directly heated from the lower side.

In addition, although there is also a small amount of microwaves that reach the upper side of the heating chamber 34 from the gap between the heating pan 402 and the door 31b and the rear wall protrusion 420 (circulation fan unit accommodating portion), it is not enough to support the load from the upper side. The food placed on the heating plate 402 is heated. That is, in such a state, it is not suitable for defrosting heating of frozen food. Therefore, in the present invention, under the defrosting function, firstly, the opening portion 58 of the rotating waveguide 39 is positioned in a direction substantially perpendicular to the door 31b, and microwaves are radiated toward the door 31b or toward the rear wall protrusion 420 . As described above, there are gaps between the heating pan 402 and the door 31 b, and between the heating pan 402 and the side wall on the rear wall protrusion 420 side.

Most of the microwaves radiated from the opening portion 58 of the rotary waveguide 39 pass through the heating plate 402 through the gap between the heating plate 402 and the door 31 b and the gap between the heating plate 402 and the side wall on the rear wall protrusion 420 side. The upper side of the heating chamber 34 is reached. The microwaves are reflected by the inner wall of the heating chamber 34 and are used to heat the object to be heated (food) placed on the upper pan holder 403 . That is, the space between the inner walls of the heating chamber 402 and the heating chamber 34 due to the door 31 b and the rear wall protrusion 420 is used as a main transmission path for supplying microwaves to the upper surface of the heating pan 402 .

Although there are also microwaves reflected by the left and right side walls of the heating chamber 34, the disk holder 400, and the mounting table 35 and absorbed by the microwave absorber 406, the amount is much smaller than that when the opening 58 is oriented in a direction parallel to the door 31b. Condition. As described above, the inner glass 61 is attached to the door 31b, and the inner glass 61 functions as a transmission path with a space gap corresponding to about 2 to 3 times its own plate thickness, so that it can effectively transfer heat to the heating plate 402. Microwaves are supplied to the upper side.

Therefore, in the present invention, when the "defrosting and grilling function" is selected, first, the rotary waveguide 39 is positioned so that the opening 58 faces the door 31b in order to construct the above-mentioned main transmission path. In this state, microwaves are supplied for a predetermined first heating time T1, and the microwaves are supplied to the upper surface side of heating pan 402 of heating chamber 34 to defrost frozen foods and the like. Then, if necessary, next, the rotating waveguide 39 is operated (rotated) so that the opening portion 58 is oriented parallel to the door 31b, and microwaves are supplied for a predetermined second heating time T2. Thereby, microwave absorber 406 generates heat, and it is possible to heat or bake the thawed food from the lower side.

In addition, in the method described above, the frozen food is thawed from above by supplying microwaves to the upper side of the heating plate 402 intensively (first predetermined time T1) initially, and then centrally (second predetermined time T2) to supply microwaves to the microwave oven. Absorber 406, thereby heating the thawed frozen food from below. In this case, the lower side is heated after the upper side of the frozen food is heated (thawed), and the heat distribution of the food may be uneven. In consideration of such a situation, the position of the opening portion 58 may be changed intermittently or intermittently.

Specifically, first, instead of stopping the open portion 58 in the direction parallel to the door 31b for the first heating time T1, the frozen food is slightly thawed by stopping for a time shorter than the first heating time. Next, the opening portion 58 is positioned in a direction perpendicular to the door 31b, and heated (grilled) by the microwave absorber 406 for a time shorter than the second heating time T2. Repeat this action. In this method, the total time for direct heating (thawing) by microwaves and the total time for heating (grilling) by microwave absorber 406 does not have to be the same as the first heating time T1 and the second heating time T2, and is appropriately determined.

In addition to the above two methods, the rotating waveguide 39 may be rotated at a constant speed without stopping the opening portion 58 in a predetermined direction. In this case, depending on the orientation of the opening portion 58, heating by microwaves supplied to the upper surface of the heating pan 402 (thawing function) and heating by the microwave absorber 406 on the lower surface of the heating pan 402 (grilling function) are performed continuously. process alternately.

Next, the relationship between the orientation of the opening portion 58 of the rotary waveguide 39 in the heating chamber 34 and the amount of microwaves supplied to the upper side of the heating plate 402 will be described with reference to FIGS. 11A to 11C and FIGS. 12A and 12B. The microwave emitted from the lower surface side of the heating pan 402 reaches the upper surface side of the heating pan 402 through the gap (mainly the inner glass 61) between the heating pan 402 and the inner wall (including the door 31b) of the heating chamber 34. It was confirmed by the methods shown in FIGS. 11A to 11C .

The heating plate 402 shown in FIGS. 11A to 11C corresponds to FIGS. 9A to 9C , respectively. The amount of microwaves can be confirmed by the temperature of the water placed on the upper surface of the heating pan 402 . First, an insulator is placed on the upper surface of the heating plate 402 as the spacer S for heat insulation. A resin container V storing 150 cc of water W was placed thereon. In addition, the spacer S for heat insulation is used to prevent the heat from the heating plate 402 from being conducted to the water W via the resin container V, and to measure the temperature rise of the water W only by the microwaves that are passed around.

When the amount of water W is represented by m [g], the specific heat capacity of water W is represented by C, the temperature rise of water W is represented by ΔT, and the heating time is represented by t[s], it can be expressed as in formula (1). The electric power P[W] absorbed by the water W is shown on the graph.

P＝4.19×m×C×ΔT/t····(1)

However, in this embodiment, C=1, m=150g.

Specifically, when the water W with an initial temperature of 20° C. reaches 60° C. when heated by the microwave oven 31 for t=180 [s], the equation (2) can be obtained from the equation (1).

P＝4.19×150×1×(60-20)/180＝140[W]····(2)

Next, the relationship between the orientation of the opening 58 of the rotary waveguide 39 and the circumvention amount of microwaves (directivity of microwaves relative to the orientation of the opening 58 ) will be described with reference to FIGS. 12A and 12B . FIG. 12A is a plan view of heating pan 402 placed inside heating chamber 34 as shown in FIG. 10A . In this figure, the front side is the door 31b side, the rear wall protruding portion 420 (circulation fan unit accommodating portion) side is the rear wall side, the right side is the right inner wall side of the heating chamber 34, and the left side is the left inner wall side of the heating chamber 34. . Viewed from the opening 58 of the rotating waveguide 39, the directions are 180°, 0°, 90° and 270°, respectively.

In FIG. 12B , the orientation of the highly directional rotating waveguide 39 (opening portion 58 ) is represented by an angle. The direction toward the rear wall protruding portion 420 (circulation fan unit accommodating portion) is defined as a reference (0°), and the clockwise direction viewed from above is defined as the + side. The difference from the reference is graphically shown at intervals of 15° with reference to the amount of winding in the case of rotation. From this figure, it can be seen that the directionality is the largest at 180°, that is, the front (door 31b side), followed by the rear (rear wall protrusion 420 side), and the left and right are smaller.

FIG. 13 shows the orientation of the opening 58 , the amount of microwave arrival, and the difference from the rotation. That is, it can be seen that microwaves radiated from the rotary waveguide 39 can be efficiently supplied toward the heating plate 402 when the rotary waveguide 39 is held at a position where the open portion 58 faces the door 31b (inner glass 61 ) side. Moreover, when the opening part 58 faces the rear wall protrusion part 420 (circulation fan unit accommodating part) side, the circumvention amount of a microwave is also larger than the case where it faces the right and left inner wall side.

Based on the relationship ( FIG. 12 ) between the orientation of the opening portion 58 of the rotary waveguide 39 obtained in this way and the amount of microwaves (directivity of the microwave) ( FIG. 12 ), the position (angle) at which the rotary waveguide 39 stops during thawing can be appropriately determined. and time.

From the above, in the microwave oven 31, the control unit 411 causes the opening portion 58 to radiate the microwave MW for the first predetermined time T1 at the first position D1 where the microwave MW has a large amount of circumvention, and at the second position D1 where the microwave MW has a small circumvention amount. The position D2 radiates the microwave MW for the second predetermined time T2, and the frozen food can be heated and cooked continuously from thawing in the state placed on the heating plate 402 . In addition, the first position D1 is a position of 180° or 0° in FIG. 12B , and the second position D2 is a position of 90° or 270°. In addition, the first position D1 and the second position D2 can be appropriately determined according to the microwave oven 31 .

In addition, the control unit 411 may continuously radiate the microwave MW at the second position D2 for the second predetermined time T2 after continuously radiating the microwave MW at the first position D1 for the first predetermined time T1 . In addition, it is also possible that the control unit 411 repeats the following process until the sum of the first small heating time ΔT1 and the second small heating time ΔT2 exceeds the first predetermined time T1 and the second predetermined time T2: make the microwave MW at the first After the position D1 continuously radiates the first small heating time ΔT1 shorter than the first predetermined time T1 , the microwave MW is continuously radiated at the second position D2 for the second small heating time ΔT2 shorter than the second predetermined time T2 .

In addition, in this embodiment, the mode using the heating pan 402 provided with the microwave absorber 406 was demonstrated. As another embodiment, it is conceivable to use a heat-resistant tray in which the microwave absorber 406 is not provided instead of the heating pan 402 . Also in this case, the same effect as that of the present invention can be obtained by using the inside of the door as a microwave transmission path, controlling the orientation of the rotary waveguide 39, and adjusting the amount of microwave reaching the upper side of the tray.

In addition, a temperature detection unit for detecting the temperature of the object to be heated may be provided, and only when the temperature of the object to be heated is low and it is determined to be a frozen product, the control unit 411 directs the rotating waveguide 39 as a directional power supply unit toward direction of door 31b and stop. Thereby, a thawing function can be exhibited, and the amount of microwaves introduced above the heating plate 402 can be increased to efficiently thaw.

When the temperature of the object to be heated is high and it is determined to be a refrigerated product or a normal temperature product, since it is not necessary to thaw, the amount of wrapping can be reduced. Thereby, it is not necessary to direct and stop the rotating waveguide 39 in the direction of the door 31b, and it is only necessary to perform the grilling function and to perform grilling efficiently.

When increasing the amount of winding, it is not necessary to stop the rotating waveguide 39 from the beginning to the end. The operation of rotating after stopping for a predetermined time may be repeated. At this time, consider changing the stop time according to the temperature of the object to be heated. The lower the temperature, the longer the stop time, and the higher the temperature, the shorter the stop time, so that the amount of winding can be controlled in multiple levels according to the temperature of the object to be heated.

Alternatively, a weight detection unit for detecting the weight of the object to be heated may be provided, and in particular, when the object to be heated is determined to be heavy, the control unit 411 stops the rotating waveguide 39 in the direction of the door 31b. Considering that the weight is heavy, the size is basically large, and there is a tendency that the central part of a large item tends to be difficult to heat only by heat conduction. In this case, heating with microwaves is considered to be easy to heat to the central part. Therefore, by making the rotating waveguide 39 stop in the direction of the door and increasing the amount of microwaves reaching the upper side of the heating plate, it is possible to efficiently heat a large object to the center.

When it is judged that the weight of the object to be heated is light, it is considered that the size is basically small, and there is a tendency for small objects to be heated to the central part even by heat conduction, so the amount of winding is small. Can. Therefore, what is necessary is just to perform grilling function efficiently, without making the rotating waveguide 39 stop facing the direction of a door.

When increasing the amount of winding, it is not necessary to stop the rotating waveguide 39 from the beginning to the end. The operation of rotating after stopping for a predetermined time may be repeated. At this time, consider changing the stop time according to the weight of the object to be heated. The heavier the weight, the longer the stop time, and the lighter the weight, the shorter the stop time, so that the amount of winding can be controlled in multiple levels according to the weight of the object to be heated.

In addition, as a safety measure in the case where a plate other than the heating plate 402 is misused even though the menu of “thawing and grilling function” is selected, a misuse determination unit may be provided. In this case, when the misuse determination unit determines that the heating disk 402 has been misused, the control unit 411 preferably continues the rotation without stopping the rotating waveguide 39 .

Normally, when using a normal heating pan 402, the control part 411 can stop the rotating waveguide 39 toward the door, and can make microwaves reach|attain on the heating pan and be efficiently absorbed by food. In addition, since the microwave absorber 406 that absorbs microwaves is provided on the lower surface of the heating plate, all the microwaves in the heating chamber can be safely consumed.

In the case of not using the regular heating plate 402, it is considered that, for example, the food is only placed on the mounting table without the heating plate 402, or a metal plate different from the heating plate 402 is placed, or both the heating plate 402 and the food are forgotten. Putting it in and starting it completely under no-load conditions can cause misuse. In particular, if a metal plate different from the heating plate 402 is placed, there is no portion capable of absorbing microwaves on the lower surface of the metal plate, and there is no portion capable of absorbing microwaves at all under a no-load condition. At this time, the electric field in the heating chamber 34 becomes strong, but if the rotating waveguide 39 is further stopped, the strong electric field may be locally concentrated. Therefore, when it is determined that the heating disk 402 is misused, the rotary waveguide 39 is continuously rotated without stopping, thereby preventing local concentration of a strong electric field.

In addition, when it is judged to be misused, it is considered to reduce or stop the output of the microwave. As a specific misuse judgment unit, a switch may be pressed by the heating disk 402 when the heating disk 402 is mounted in the heating chamber 34 . A switch is arranged at the attachment position of the end portion of the heating plate 402, and if the switch is not pressed, it can be judged as misuse that the regular heating plate 402 is not used.

As another misuse determination unit, a temperature detection unit that detects the temperature of at least one of the heating pan 402 or the object to be heated may be provided. When a temperature different from the predetermined temperature is detected, it can be judged as misuse that the regular hot plate 402 is not used.

In addition, as another misuse determination unit, a weight detection unit that detects the weight of at least one of the heating pan 402 or the object to be heated may be provided. When a weight different from the predetermined weight is detected, it can be judged as misuse that the regular hot plate 402 is not used.

Although this invention was demonstrated with reference to the specific embodiment in detail, it is clear for those skilled in the art that various changes and correction can be added without deviating from the mind and range of this invention.

Industrial availability

Since the present invention can continuously heat from thawing, it can be used in microwave heating devices such as microwave ovens.

Label description

31: microwave oven (microwave heating device); 31a: main body; 31b: door; 31c: operation part; 32: magnetron (microwave generator); 33: waveguide; 34: heating chamber; 35: mounting table; 37: Power supply part; 38: Front surface opening; 39: Rotary waveguide (directional power supply part); 41: Motor; 42: Bottom surface of heating chamber (mounting table); 58: Opening part; 60: Metal plate; 61: Inner glass ( glass); 62: outer glass; 90: rotating waveguide; 91: rotating waveguide; 92: opening part; 93: opening part; 400: tray support part; 402: heating plate (tray); 402a: surrounding part; 402b : Groove; 402c: Plate; 403: Pan support for upper layer; 404: Pan support for middle layer; 405: Pan support for lower layer; 406: Microwave absorber; 411: Control unit; 412: Circulation fan unit accommodation; 420: Rear wall protrusion.

Claims (11)

1. A microwave heating cooker, which has: A heating chamber, the opening of the front surface of the heating chamber is provided with a glass door, and the heating chamber accommodates the object to be heated; a microwave-permeable mounting table, the mounting table constituting the bottom surface of the heating chamber; a tray, the tray is detachably attached to the heating chamber, and the tray places the object to be heated; a tray support part, the tray support part is arranged in the heating chamber and supports the tray; microwave generation unit; a waveguide that transmits the microwaves from the microwave generating part to the heating chamber; a directional power supply part having directivity, which supplies the microwave from the waveguide to the heating chamber; a drive unit, the drive unit drives the directional power supply unit to rotate; a control unit, the control unit controls the driving unit so that when the object to be heated is in a frozen state, the directional power supply unit is concentrated in the direction of the door, thereby using the inside of the glass as main transmission path, and make the upper end of the glass installed on the door be located above the tray holder, thereby supplying the microwave to the space above the tray; and The power supply unit is formed below the mounting table and accommodates the directional power supply unit. 2. The microwave heating cooker according to claim 1, wherein: The tray is a heating plate provided with a microwave absorber on the lower surface. 3. The microwave heating cooker according to claim 1, wherein: The control unit stops the directional power feeding unit at a position where the directional power feeding unit faces the door. 4. The microwave heating cooker according to claim 1, wherein: The control unit swings the directional power feeding unit near a position where the directional power feeding unit faces the door. 5. The microwave heating cooker according to claim 1, wherein: The control unit may rotate the directional power feeding unit while decelerating the directional power feeding unit in the vicinity of the direction of the door during microwave heating. 6. The microwave heating cooker according to claim 1, wherein: The microwave heating cooker further includes a temperature detection unit for detecting the temperature of the object to be heated, The control unit determines whether the object to be heated is frozen based on the output of the temperature detection unit, and controls the driving unit so that the direction The directional power supply unit is directed toward the door in a concentrated manner, and when it is determined that the object to be heated is not in a frozen state, the driving unit is controlled so that the directional power supply unit is directed in a direction other than the door. This controls the amount of microwaves supplied to the space above and below the tray. 7. The microwave heating cooker according to claim 1, wherein: The microwave heating cooker further includes a weight detection unit for detecting the weight of the object to be heated, The control unit controls the drive unit based on the weight of the object to be heated to change the direction of the directional power feeding unit and control the supply amount of microwaves to the space above and below the tray. 8. The microwave heating cooker according to claim 1, wherein: The microwave heating cooker further includes a misuse judgment unit for judging misuse of the tray, When the misuse of the tray is determined by the misuse determination unit, the control unit rotates the directional power supply unit. 9. The microwave heating cooker according to claim 8, wherein: The misuse judgment unit has a switch that is pressed by the tray when the tray is attached to the heating chamber, and judges that the tray is not used as misuse when the switch is not pressed. 10. The microwave heating cooker according to claim 8, wherein: The misuse determination unit has a temperature detection unit that detects the temperature of at least one of the tray or the object to be heated, and determines that the tray is not used when a temperature different from a predetermined temperature is detected. Misuse. 11. The microwave heating cooker according to claim 8, wherein: The misuse determination unit has a weight detection unit that detects the weight of at least one of the tray or the object to be heated, and determines that the tray is not used when a weight different from a predetermined weight is detected. Misuse.

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