JP7795412B2 - microwave oven - Google Patents

Description

The present invention relates to a microwave oven.

Recent microwave ovens are capable of automatically heating food placed in the heating chamber according to a set menu, and the number of menu options available is increasing. If all menu options were printed on the exterior of the microwave oven and a display unit was provided to show the selected menu, in order to select one of several options, this would improve usability for the user, but would detract from the microwave oven's design.

Patent Document 1 discloses a microwave oven with a menu guide that can be stored in the exterior. In this microwave oven, for example, by displaying multiple menus on the menu guide and providing a display unit on the exterior that can display the multiple menus individually, usability can be improved without compromising the design.

Japanese Utility Model Application Publication No. 59-65313

In this type of microwave oven, the space between the exterior body and the heating chamber serves as a placement area for electrical components, and it is preferable to ensure ventilation in this placement area and improve the cooling of the electrical components. However, the microwave oven in Patent Document 1 does not give any consideration to the cooling of the electrical components placed in the placement area.

The objective of the present invention is to provide a microwave oven that can improve the cooling performance of electrical components placed inside the exterior without compromising design and usability.

One aspect of the present invention provides a microwave oven comprising: an exterior; a heating chamber provided within the exterior for heating food using microwaves; a placement section formed between the exterior and the heating chamber and in which electrical components are placed; a menu board attached to the exterior so as to allow movement between a use position in which a predetermined number of menus are displayed and in which the plurality of menus are exposed from the exterior and a non-use position in which the plurality of menus are concealed by the exterior; a display section capable of selectively displaying the plurality of menus; and an operation section capable of changing the menu displayed on the display section and selecting one of the plurality of menus; the exterior has an air intake hole for drawing air from outside the placement section into the interior; and the menu board has a vent hole that communicates with the air intake hole when in the non-use position.

A menu board is attached to the exterior body so that it can be moved between a use position where multiple menus are exposed and a non-use position where they are covered. By operating the operation unit to match the menu displayed on the display unit with the desired menu, a predetermined automatic heating process can be performed. This improves usability for users while preventing the microwave's design from being compromised compared to when multiple menus are all printed on the surface of the exterior body. The exterior body also has an intake hole for drawing air from outside the storage area into the interior, and the menu board has an air vent that connects to the storage area between the heating chamber and the exterior body when in the non-use position, thereby improving the cooling of electrical components placed within the storage area. This prevents the microwave oven (controller) from malfunctioning due to an excessive rise in temperature within the storage area.

A door is attached to the exterior body so as to be able to open and close, covering the opening of the heating chamber. The menu board is located on the bottom side of the exterior body, and the ventilation hole is located at the end of the menu board closest to the door. In other words, the ventilation hole is located in a part of the menu board where there are no components that would obstruct ventilation under normal usage conditions. This ensures good ventilation inside and outside the area where it is placed.

The electrical components include a fan for drawing air from outside the placement section into the interior and discharging the air inside the placement section to the outside. An exhaust hole is provided in the placement section downstream of the airflow from the fan for discharging the air inside the placement section to the outside. The electrical components include a power supply board, inverter, and microwave source arranged in this order from the intake hole to the exhaust hole. A fan is provided that draws air through the intake hole provided downstream of the air hole and discharges it through the exhaust hole. This ensures forced air cooling of the electrical components in the placement section between the heating chamber and the exterior body, more specifically the power supply board, inverter, and microwave source.

The vent hole and the intake hole pass through in directions that intersect with each other. This prevents electrical component failure (short circuit) caused by thin, linear objects entering the placement section from outside the exterior body through the vent hole and intake hole.

The menu board displays a two-dimensional code for referencing heating settings for menus other than the multiple menus. This allows users to read the two-dimensional code using a communication device such as a mobile phone or personal computer and refer to a dedicated website, which may enable them to heat food at the optimal settings even for menus not displayed on the menu board. This improves user convenience.

The microwave oven of the present invention can improve the cooling performance of electrical components placed inside the exterior without compromising design or usability.

1 is a perspective view showing a microwave oven according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of the microwave oven of FIG. 1 cut at the center in the front-to-rear direction. 2 is a cross-sectional view of the microwave oven of FIG. 1 cut at the center in the width direction. FIG. 2 is a front view of the microwave oven of FIG. 1; FIG. 5 is an exploded perspective view of the microwave oven of FIG. 4 as seen from below. FIG. 6 is a plan view of the menu board of FIG. 5 . FIG. 6 is an exploded perspective view of the microwave oven of FIG. 5 .

The following describes an embodiment of the present invention with reference to the drawings.

Figures 1 to 3 show a microwave oven 1 according to an embodiment of the present invention. The X direction in the drawings is the front-to-rear direction of the microwave oven 1, with the direction indicated by the arrow being the rear side and the direction opposite the arrow being the front side. The Y direction is the width direction of the microwave oven 1, with the direction indicated by the arrow being the left side and the direction opposite the arrow being the right side. The Z direction is the height direction of the microwave oven 1, with the direction indicated by the arrow being the top side and the direction opposite the arrow being the bottom side.

Referring to Figures 1 to 3, the microwave oven 1 comprises a microwave body 10 having a heating chamber 21, and a door 32 attached to the microwave body 10 so as to be able to open and close. The microwave oven 1 also comprises a magnetron 40 and heater 41 for heating the food in the heating chamber 21, an infrared sensor (first sensor) 42 and a thermistor (second sensor) 43 for detecting temperature, and a control unit 45.

Referring to Figures 4 to 6, the front of the microwave body 10 is provided with three operation units 50-52 and an LCD panel (display unit) 54, and a menu board 56 is attached to the exterior bottom surface of the microwave body 10. By operating the operation units 50 and 51, the number displayed on the LCD panel 54 is changed to match the number 58 corresponding to the menu 57 displayed on the menu board 56. This causes the control unit 45 to control the magnetron 40 and heater 41 based on the temperatures detected by the infrared sensor 42 and thermistor 43, respectively, and perform the heating process specified for the selected menu 57.

Referring to Figures 1 to 3, the microwave oven 1 of this embodiment includes a dedicated plate 60 and container 65 that are detachably placed in the heating chamber 21, and the food to be heated can be placed not only directly on the bottom wall 22 of the heating chamber 21, but also in the dedicated container 65.

The microwave body 10, door 32, menu board 56, plate 60, and container 65 will be described in detail below.

Referring to Figures 1 to 3, the microwave oven body 10 comprises an exterior body 11 and a heating chamber 21 provided within the exterior body 11. The volume of the heating chamber 21 is smaller than the volume of the exterior body 11, and the space between the exterior body 11 and the heating chamber 21 forms a mounting section 30 in which electrical components such as a magnetron 40 are disposed.

The exterior body 11 is defined by a bottom wall 12, a top wall 13, a pair of side walls 14, a rear wall 15, and a front wall 16. These walls 12 to 16 are all made of metal plates that are microwave reflectors.

Referring to Figures 5 and 7, the bottom wall 12 is cylindrical and includes a generally rectangular bottom portion 12a extending along the XY plane, a cylindrical outer peripheral portion 12b rising from the outer periphery of the bottom portion 12a, and a flange portion 12c provided at the upper end of the outer peripheral portion 12b. Referring to Figures 1 to 3, the top wall 13 is made of a rectangular plate extending along the XY plane and faces the bottom portion 12a in the height direction. The pair of side walls 14 are each made of rectangular plate members extending along the XZ plane and face each other in the width direction. In this embodiment, the top wall 13 and the pair of side walls 14 are formed integrally by press working. The rear wall 15 is made of a rectangular plate member extending along the YZ plane with a central portion bulging rearward. The front wall 16 is made of a rectangular frame member extending along the YZ plane and with a central opening. These walls 12 to 16 are connected by screws.

The heating chamber 21 is defined by a bottom wall 22, a top wall 23, a pair of side walls 24, a rear wall 25, and a door 32, all of which are rectangular plates. Of these, the bottom wall 22 is made of a material that is transparent to microwaves, such as ceramic, glass, or resin, and is attached to the upper end of a metal cover 27, which acts as a microwave reflector. The top wall 23, the pair of side walls 24, and the rear wall 25 are all made of metal plates that also act as microwave reflectors. The door 32 will be described in more detail below.

The bottom wall 22 extends along the XY plane and is connected to the upper end of the outer periphery 12b of the bottom wall 12 via a cover 27 by screws. The space between this cover 27 and the bottom 12a of the exterior body 11 forms the electrical component placement section 30. The top wall 23 is disposed facing the upper side of the bottom wall 22 in the height direction and extends along the XY plane. The pair of side walls 24 both extend along the XZ plane and face each other in the width direction. The lower ends of the pair of side walls 24 are continuous with the cover 27, and the upper ends of the pair of side walls 24 are continuous with the top wall 23. The front ends of the cover 27, the top wall 23, and the pair of side walls 24 are continuous with the front wall 16 of the exterior body 11, defining the opening 26 of the heating chamber 21. The rear wall 25 extends along the YZ plane and is continuous with the rear ends of the cover 27, the top wall 23, and the pair of side walls 24.

Referring to Figures 1 and 2, each of the pair of side walls 24 is provided with guide rails 28, 29 for positioning the plate 60. The guide rails 28, 29 are formed by pressing a portion of the side wall 24 to bulge toward the widthwise center of the heating chamber 21, and are provided so as to extend in the front-to-rear direction. Of these, the upper guide rail 28 is provided in an area above the center of the overall height of the heating chamber 21, and is disposed at the same height position on each of the pair of side walls 24. The lower guide rails 29 are provided in an area below the center of the overall height of the heating chamber 21, and are disposed at the same height position on each of the pair of side walls 24.

Referring to Figures 1 and 3, the door 32 is attached to the front side of the exterior body 11 and releasably closes the opening 26 of the heating chamber 21. The door 32 can rotate around a rotation axis (not shown) extending in the width direction between an open position shown in Figure 1 and a closed position shown in Figure 3. The door 32 includes a frame 33 made of opaque resin that is transparent to microwaves, and a window 34 through which the interior of the heating chamber 21 can be seen. A reflective layer 35 made of punched metal with a large number of holes, for example, 1 mm in diameter, that can reflect microwaves and ensure visibility is provided on the inside of the window 34. However, the door 32 may also be configured to rotate horizontally around a rotation axis that extends in the height direction.

Referring to Figures 2 and 3, the range body 10 further includes a magnetron 40, a heater 41, an infrared sensor 42, a thermistor 43, and a control unit 45.

The magnetron 40 is a microwave source that outputs microwaves and is located at the end of a metal duct (waveguide) 40a. The magnetron 40 and duct 40a are located within the mounting section 30, and the end of the duct 40a opposite the magnetron 40 is connected to the cover 27. A motor-rotatable antenna 40b is located within the cover 27, positioned at the center of the bottom wall 22 in the width and front-to-back directions. The microwaves output by the magnetron 40 are guided into the cover 27 by the duct 40a and output from the bottom wall 22 into the heating chamber 21 via the antenna 40b, heating the food. The area of the bottom wall 22 designated by the symbol 40c constitutes the microwave transmission area, i.e., the output section that outputs microwaves into the heating chamber 12.

The heater 41 is disposed adjacent to the heating chamber 21 side of the top wall 23 so as to be located above the upper guide rail 28, and heats the food inside the heating chamber 21 by radiant heat. In this embodiment, a pair of heaters 41 are disposed at a distance in the front-to-rear direction, and each extends in the width direction. However, only one heater 41 may be provided, positioned centrally in the front-to-rear direction, or three or more heaters may be provided. The heaters 41 may also be disposed at a distance in the width direction and extend in the front-to-rear direction. A heater may also be disposed below the bottom wall 22.

The infrared sensor 42 is a thermopile type equipped with an infrared detection element that detects the temperature of the food being cooked inside the heating chamber 21. Referring to Figure 2, the infrared sensor 42 is positioned in a recessed groove outside the heating chamber 21 formed by the upper guide rail 28 on the right side wall 24. The infrared sensor 42 is attached so as to face the inside of the heating chamber 21 through a through-hole provided in the center of the upper guide rail 28 in the front-to-rear direction.

Referring to Figures 2 and 3, the thermistor 43 comprises a main body (not shown) located above the top wall 23, outside the heating chamber 21, and a detection unit 43a that penetrates the top wall 23 and is located inside the heating chamber 21, and detects the temperature inside the heating chamber 21. More specifically, the detection unit 43a is located at a corner of the heating chamber 21 defined by the top wall 23, rear wall 25, and right-hand side wall 24 in Figure 2. A guard protrusion that is positioned in front of the thermistor 43 and protrudes in a roughly quadrangular pyramid shape toward the left-hand side wall 24 is formed on the right-hand side wall 24 by pressing.

The control unit 45 consists of, for example, a single microcomputer and is electrically connected to the magnetron 40, heater 41, infrared sensor 42, thermistor 43, etc. Based on the detection results of the infrared sensor 42 and thermistor 43, the control unit 45 controls the magnetron 40 and heater 41 to heat the food in the heating chamber 21 (heating process).

The heating process performed by the control unit 45 includes microwave heating mode (range cooking), heater heating mode (grill cooking), and combined heating mode (combined cooking). In microwave heating mode, only the magnetron 40 is operated until heating is complete based on the detection results of the infrared sensor 42 and thermistor 43. In heater heating mode, only the heater 41 is operated until heating is complete based on the detection results of the thermistor 43. In combined heating mode, both the magnetron 40 and heater 41 are operated based on the detection results of the infrared sensor 42 and thermistor 43.

Next, we will explain the dedicated plate 60 and container 65 used in the microwave oven 1.

Referring to Figures 1 and 2, the plate 60 is rectangular when viewed from above and includes a saucer-shaped main body 60a and a flange portion 60b consisting of a rectangular frame attached to the upper end of the main body 60a and extending along the XY plane. Resin cushioning members 61 are attached to both sides of the flange portion 60b in the width direction. The plate 60 configured in this manner is detachably positioned within the heating chamber 21 by being placed on a pair of upper guide rails 28 or a pair of lower guide rails 29. The plate 60 is made of a material that is transparent to microwaves, such as ceramic, glass, or resin, and can be used in all of the microwave heating mode, heater heating mode, and combined heating mode.

A pair of hanging rails 62 for attaching a container 65 are provided on the surface of the plate 60 facing the bottom wall 22. The hanging rails 62 have an L-shaped cross section and can detachably support the container 65.

Referring to Figures 1 and 2, the container 65 is a cylindrical container with a bottom, including a circular bottom wall 65a and a conical side wall 65b, and is made of a microwave-transparent material such as ceramic, glass, or resin, just like the plate 60. An outer flange 65c is formed at the top end of the container 65, and is supported by the suspension rail 62. Attached to the underside of the flange 65c is an annular buffer member 66 made of a flexible material (e.g., silicone rubber) that prevents direct interference between the suspension rail 62 and the container 65.

Next, we will explain in more detail the heating process performed by the control unit 45.

The control unit 45 executes one of the following functions shown in Figure 4: "Oven," "Grill," "Microwave," "Automatic," "Register," "Float Register," and "Defrost" according to a pre-stored program.

"Microwave," "Float," and "Defrost" are performed in microwave heating mode. Specifically, "Microwave" and "Defrost" are performed with the food placed on a designated plate on the bottom wall 22 of the heating chamber 21, and the food is heated by microwaves generated by the magnetron 40. "Float" is performed with the food contained in a container 65 placed in the heating chamber 21 via the plate 60, and the food is heated by microwaves generated by the magnetron 40.

The "oven" and "grill" modes are operated in heater heating mode. Specifically, the "oven" and "grill" modes are operated with the food placed on a designated tray on the bottom wall 22, or with the food placed on the plate 60 inside the heating chamber 21, and the food is heated by radiant heat from the heater 41.

"Regis-grilling" is performed in the combined heating mode. Specifically, "Regis-grilling" is performed with the food placed on a designated plate on the bottom wall 22, and the food is heated using microwaves from the magnetron 40 and radiant heat from the heater 41. For example, the magnetron 40 is activated, and microwave heating is used to cook the food to the center. After a preset microwave heating time or a microwave heating time set by the user has elapsed, the magnetron 40 is stopped. Next, the heater 41 is activated, and the surface of the food is browned by heater heating. After a preset heater heating time or a heater heating time set by the user has elapsed, the heater 41 is stopped.

In "Automatic," one of the multiple menus 57 shown in FIG. 6 is selected and performed in a specified heating mode. Specifically, the multiple menus 57 include menus performed in microwave heating mode (e.g., "1. Warm refrigerated rice"), menus performed in heater heating mode (e.g., "10. Toast (inside out)"), and menus performed in combined heating mode (e.g., "7. Deep-fried food 'Sacred'"). "Automatic" is performed with the food placed on a specified plate on the bottom wall 22, and the food is heated in either microwave heating mode, heater heating mode, or combined heating mode specified by the menu 57.

Next, we will explain the configuration for selecting one of multiple heating modes and the configuration for selecting one of multiple menus.

Referring to Figure 4, the door 32 has three operating units 50-52 and one LCD panel 54 below the window 34. The operating units 50-52 and the LCD panel 54 are electrically connected to the control unit 45, and the control unit 45 detects operation of the operating units 50-52 and changes the display on the LCD panel 54. In addition, a menu board 56 is attached to the outer bottom surface of the microwave body 10.

The operation unit 50 is provided for selecting one of several heating modes: "Oven," "Grill," "Microwave," "Auto," "Regis-Grill," "Float-Grill," and "Defrost," and in this embodiment is configured as a rotary switch. LEDs 50a are located on the operation unit 50 side that indicate each heating mode. Operation of the operation unit 50 is detected by the control unit 45, which changes which LEDs 50a are lit depending on the rotation direction and rotation angle range of the operation unit 50. A lit LED 50a indicates a selected heating mode, and an unlit LED 50a indicates a non-selected heating mode.

The operation unit 51 is provided for setting the details of the heating mode selected by the operation unit 50 and for starting the heating mode, and in this embodiment is configured as a rotary push switch. Specifically, in heating modes other than "automatic," the heating time and input power (heating temperature) displayed on the LCD panel 54 can be changed by rotating the operation unit 51. In "automatic," the number in the numeric display unit 54a (described below) on the LCD panel 54 can be changed by rotating the operation unit 51, allowing one of multiple menus 57 shown in FIG. 6 to be selected. The operation unit 51 can be pushed to confirm the detailed settings of the heating mode and to execute the set heating mode. The operation of the operation unit 51 is detected by the control unit 45, which then changes the display on the LCD panel 54, changes the heating mode setting, and starts heating in the set heating mode (menu 57 numbered 58 that matches the number set in the numeric display unit 54a).

Operation unit 52 is provided to cancel (cancel) settings made by operating operation units 50 and 51, and in this embodiment is configured as a push switch. Operation of operation unit 52 is detected by control unit 45, which then cancels the change to the heating mode setting and stops the heating mode that has been executed.

The LCD panel 54 has a numeric display section 54a capable of displaying three-digit numbers. The LCD panel 54 can also display letters, arrows, and other characters in addition to numbers. The display on the LCD panel 54 is changed by the control section 45, which detects operation of the operation sections 50-52. The LCD panel 54 may be a segment display type or a dot matrix display type, as long as it can display two or more digits. By displaying a number 58 on the numeric display section 54a, the corresponding menu 57 is indirectly displayed. In other words, the numeric display section 54a is a specific display area that can selectively and individually display multiple menus 57. A specific display area is a display section that displays a menu 57 using the same segments or dots, depending on the menu 57.

Referring to Figures 4 to 6, the menu board 56 is slidably positioned on the outer bottom surface of the microwave body 10. As can be seen most clearly in Figure 6, the top surface of the menu board 56 lists menu items 57 that can be heated in the "automatic" heating mode. The multiple menu items 57 include "Reheat refrigerated rice," "Reheat frozen rice," "Drinks," ... and "Deodorization." Next to each menu item 57 is listed a number 58 corresponding to "1," "2," "3," ... "36." The number 58 is different for each menu item 57.

The heating mode is set to "automatic" by rotating the operation unit 50, and the desired menu 57 and the corresponding number 58 are displayed in the number section 54a of the LCD panel 54 by rotating the operation unit 51. When the operation unit 51 is pushed in this state, the control unit 45 detects this operation and activates the magnetron 40 or heater 41 according to a preset program to heat the food.

A two-dimensional code, QR Code (registered trademark) 59, is printed on one corner of the menu board 56 that is located on the rear side when attached to the microwave body 10. QR Code 59 is a two-dimensional code for accessing a dedicated website via a network such as the Internet using a communication device such as a mobile phone or personal computer. For example, by reading QR Code 59 with a mobile phone and accessing the dedicated website via the network, it is possible to check the heating settings for menus other than the multiple menus 57 printed on menu board 56. If a menu can be heated using the same settings as one of the multiple menus 57, a number 58 corresponding to that menu 57 is displayed on the dedicated website. Furthermore, if the heating setting is different from any of the multiple menus 57, an appropriate heating mode other than "automatic," the heating time, input power, etc., is displayed.

Next, we will explain the configuration of the menu board 56 in more detail.

5 and 7, the menu board 56 is removably attached to the guide rails 17a of a pair of pedestals 17 attached to both sides of the bottom wall 12. By pulling out the menu board 56 from the unused position shown in FIG. 3, the multiple menus 57 can be exposed from the exterior body 11 (used position). In this embodiment, the menu board 56 is configured to be removable as shown in FIG. 5, but it may also be configured to be non-removable. Furthermore, in this embodiment, the menu board 56 is attached slidably, but it may also be attached rotatably. In other words, the menu board 56 only needs to be attached to the exterior body 11 so as to be movable between the used position in which the multiple menus 57 are exposed from the exterior body 11 (see FIG. 5 as an example), and the unused position in which the multiple menus 57 are covered by the exterior body 11 (see FIG. 3).

When in the unused position, the menu board 56 is located below the bottom wall 12, which is the bottom of the microwave body 10. A pair of bases 17 are made of resin and are each located outside the outer periphery 12b of the bottom wall 12 and connected to the bottom wall 12 with screws. A front cover 18, which is located below the door 32, is attached to the front side of the bottom wall 12. Referring to Figures 4 and 5, the front cover 18 is made of resin and has a cutout 18a that corresponds to the shape of the menu board 56 when viewed from the front.

Referring to Figures 5 to 7, the menu board 56 comprises a board body 56a on which multiple menus 57 and numbers 58 are printed, and a handle 56d that is located below the front cover 18 when attached to the microwave body 10.

When attached to the microwave oven body 10, the board body 56a is plate-shaped and extends along the XY plane. When attached, the majority of the rear portion of the board body 56a overlaps the underside of the bottom portion 12a of the bottom wall 12. Meanwhile, the front portion of the board body 56a covers the gap 31 between the outer periphery 12b of the bottom wall 12 and the front cover 18. The board body 56a has a shape that corresponds to the uneven shape of the bottom wall 12, and a notch 56b corresponding to the raised portion 12d of the bottom wall 12 is formed on the left side in Figure 5. Referring to Figure 6, elastic pieces 56c that elastically press against the outer surface of the bottom wall 12 are provided on both widthwise sides of the menu board 56.

Referring to Figure 5, the grip portion 56d is connected to the front end of the board body 56a and is gripped when inserting or removing the menu board 56. Specifically, the grip portion 56d includes a rising portion 56e connected to the front end of the board body 56a, a protruding portion 56f connected to the upper end of the rising portion 56e, and a hook 56g connected to the tip of the protruding portion 56f.

When attached to the range body 10, the rising portion 56e extends along the YZ plane and faces the outer periphery 12b of the bottom wall 12 at a distance to the front. The protruding portion 56f protrudes from the rising portion 56e in the opposite direction to the board body 56a, extends along the XY plane, and covers part of the gap 31. The hook piece 56g protrudes downward from the tip of the protruding portion 56f and is located flush with the front surface of the front cover 18.

The menu board 56 configured in this manner is provided with ventilation holes 56h that communicate with the interior of the placement section 30 of the microwave body 10 when in the non-use position shown in Figure 3 and ensure ventilation within the placement section 30. The ventilation holes 56h are provided at intervals in the width direction in the portion of the board body 56a that covers the gap 31 and in the protruding portion 56f of the gripping portion 56d. In other words, multiple ventilation holes 56h are provided in the front end of the menu board 56 that protrudes forward from the outer periphery 12b of the bottom wall 12 and is located below the door 32. Each ventilation hole 56h is oval in shape, penetrating in the height direction and extending in the width direction.

Referring to Figures 5 and 7, the exterior body 11 of the range body 10 is provided with an intake hole 68 for drawing air from outside the placement section 30 into the interior, and an exhaust hole 69 for expelling air from inside the placement section 30 to the outside. Additionally, the electrical components of a fan 70, a power supply board 75, an inverter 78, and a magnetron 40 are located within the placement section 30 between the bottom 12a of the exterior body 11 and the cover 27 of the heating chamber 21.

A plurality of air intake holes 68 are provided on the outer periphery 12b of the bottom wall 12, in a portion (front side) facing the front cover 18, and on the bottom 12a of the bottom wall 12. As will be described in detail later, the front side of the outer periphery 12b is the portion of the mounting section 30 located upstream of the airflow caused by the fan 70 and downstream of the air vent 56h. The bottom 12a is the portion that is close to and faces the installation surface of the microwave oven 1.

The air intake holes 68 in the outer periphery 12b are oval shapes that penetrate the outer periphery 12b in the front-to-rear direction and extend in the width direction, and are arranged at intervals in both the width and height directions to form a matrix. In this way, the air intake holes 68 penetrate in the front-to-rear direction at the front of the exterior body 11, while the air vent 56h penetrates in the height direction further forward than the air intake hole 68. In other words, the air vent 56h in the menu board 56 and the air intake hole 68 in the bottom wall 12 penetrate in directions that intersect with each other.

The air intake holes 68 in the bottom 12a are circular and penetrate the bottom 12a in the height direction, and are spaced apart in the width direction and the front-to-rear direction to form a matrix. No air intake holes 68 are provided in the portion of the bottom 12a that corresponds to the board case 76, which will be described in detail later. As mentioned above, because the bottom 12a is close to and faces the installation surface, the air intake holes 68 in the bottom 12a have inferior air intake capacity compared to the air intake holes 68 in the outer periphery 12b.

A plurality of exhaust holes 69 are provided in the bottom 12a and outer periphery 12b of the bottom wall 12, except for the portion located on the front side. Specifically, a plurality of oval exhaust holes 69 are provided in a matrix pattern in the portions located on both widthwise sides and the rear side of the outer periphery 12b of the bottom wall 12. Furthermore, a plurality of oval exhaust holes 69 are provided in a matrix pattern in the side wall 14 and rear wall 15 on the left side in Figure 7. No exhaust holes 69 are provided in the side wall 14 located on the right side in Figure 7.

As shown most clearly in Figure 7, the fan 70 is located in the rear right corner of the placement section 30, drawing air from outside the placement section 30 into the interior and expelling air from inside the placement section 30 to the exterior. In this embodiment, the fan 70 is a sirocco fan housed in a fan case 71. The fan case 71 comprises a case body 72 with an opening at the bottom and a cover 73 that covers the opening of the case body 72. An air intake 73a is provided on the surface of the cover 73 facing the front power supply board 75. The air outlet 72a of the fan case 71 is provided in the case body 72 and opens to face the left side in Figure 7.

The power supply board 75 is located inside the placement section 30, on the inside (front side in the front-to-back direction) of the intake hole 68, and is housed in a board case 76. The board case 76 is trough-shaped, with the air vent 76a opening rearward so that it faces the fan case 71.

The inverter 78 is located adjacent to the left side of the fan 70 within the mounting section 30 and is housed in an inverter case 79. The inverter case 79 comprises a case body 80 with an opening at the bottom and a cover 81 that covers the opening of the case body 80. The case body 80 is trough-shaped, with an intake port 80a at one end facing the outlet 72a of the fan case 71 and an outlet 80b at the other end opening to the left of the mounting section 30 in Figure 7, facing the front.

The magnetron 40 is located in front of the air outlet 80b of the inverter case 79. In Figure 7, the magnetron 40 is located on the left side and in the center in the front-to-rear direction, and to the right of this is a duct 40a, which extends to the center in the width direction.

The interior of the storage section 30 configured in this manner is partitioned by the circuit board case 76, fan case 71, and inverter case 79. Therefore, when the fan 70 is operated, air from outside the range body 10 flows into the storage section 30 primarily through the vent hole 56h and the intake hole 68 in the outer periphery 12b of the bottom wall 12, because the intake hole 68 in the bottom portion 12a of the bottom wall 12 has poor intake capacity. Within the storage section 30, air flows through the circuit board case 76 to the right in FIG. 7 and is drawn into the fan 70 in the fan case 71 through the intake port 73a. The air discharged by the fan 70 travels from the fan case 71 through the inverter case 79 to the magnetron 40 and is discharged into the storage section 30 from the left side in FIG. 7. The air is then exhausted from the interior of the storage section 30 to the outside through the exhaust holes 69 in the bottom wall 12, left side wall 14, and rear wall 15.

As described above, the fan 70 draws air into the storage section 30 primarily from the lower front of the range body 10, where it flows to the right in Figure 7, before being drawn in by the fan 70 and expelled to the left. In other words, the fan 70 creates a clockwise airflow in Figure 7 within the storage section 30, with the power supply board 75, inverter 78, and magnetron 40 arranged in that order from the intake hole 68. This ensures good ventilation within the storage section 30, ensuring reliable forced cooling of the electrical components placed inside.

The microwave oven 1 configured in this way has the following features:

A menu board 56 is attached to the exterior body 11 so that it can be moved between a use position, in which multiple menus 57 and their corresponding numbers 58 are exposed from the exterior body 11, and a non-use position, in which multiple menus 57 and their corresponding numbers 58 are concealed by the exterior body 11. Furthermore, a predetermined automatic heating process can be executed by operating the operation unit 51 to match the number displayed on the numeric display unit 54a of the LCD panel 54 with the desired menu 57 and its corresponding number 58. This improves the usability of the microwave oven 1 for users while preventing impairment of the design of the microwave oven 1 compared to when multiple menus 57 and numbers 58 are all printed on the surface of the exterior body 11. Furthermore, the exterior body 11 is provided with an intake hole 68 for drawing air outside the placement section 30 into the interior, and the menu board 56 is provided with an air vent 56h that connects to the placement section 30 between the heating chamber 21 and the exterior body 11 when in the non-use position, thereby improving the cooling of electrical components placed within the placement section 30. This prevents malfunction of the microwave oven 1 (controller 45) caused by an excessive rise in temperature inside the placement section 30.

The menu board 56 is located on the bottom side of the exterior body 11, and the ventilation hole 56h is located at the end of the menu board 56 facing the door 32. In other words, the ventilation hole 56h is located in a part of the menu board 56 where there are no components that would obstruct ventilation under normal usage conditions. This ensures ventilation inside and outside the placement section 30.

A fan 70 is provided that draws in air through an intake hole 68 located downstream of the ventilation hole 56h and expels it through an exhaust hole 69. This ensures forced air cooling of the electrical components in the arrangement section 30 between the heating chamber 21 and the exterior body 11, more specifically the power supply board 75, inverter 78, and magnetron 40.

The ventilation hole 56h and the intake hole 68 penetrate in directions that intersect with each other. This prevents electrical component failure (short circuit) caused by thin, linear objects entering the placement section 30 from outside the exterior body 11 through the ventilation hole 56h and the intake hole 68.

Menu board 56 displays a QR code 59 for referencing heating settings for menus other than the multiple menus 57. This allows users to read QR code 59 using a communication device such as a mobile phone or personal computer and refer to a dedicated homepage, which may enable them to heat food at the optimal settings even for menus not displayed on menu board 56. This improves user convenience.

Note that the present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

For example, the menu board 56 may be slidably arranged on the inner surface (top surface) of the bottom wall 12, or on the top wall 13 or side wall 14 of the exterior body 11.

Alphabet (English letters) may be displayed next to the menu 57 on the menu board 56 instead of numbers (numeric characters) 58, and the LCD panel 54 may also be provided with an English letter display section instead of the numeric display section 54a. Also, the menu board 56 may display only the menu 57 without alphanumeric characters, and menus corresponding to specific display areas on the LCD panel 54 may be selectively and individually displayed in text.

The operation unit 51 and LCD panel 54 may be provided on the front wall 16 of the exterior body 11.

The output section 40c of the magnetron 40 may be located on the rear wall 25 or on one of the pair of side walls 24, as long as it is between the bottom wall 22 of the heating chamber 21 and the upper guide rail 28.

The microwave oven 1 may not have a heater 41 and may be capable of operating only in microwave heating mode.

REFERENCE SIGNS LIST 1 microwave oven 10 microwave oven body 11 exterior body 12 bottom wall 12a bottom portion 12b outer periphery 12c flange portion 12d raised portion 13 top wall 14 side wall 15 rear wall 16 front wall 17 base 17a guide rail 18 front cover 18a cutout portion 21 heating chamber 22 bottom wall 23 top wall 24 side wall 25 rear wall 26 opening 27 cover 28 upper guide rail 29 lower guide rail 30 placement portion 31 gap portion 32 door 33 frame 34 window 35 reflective layer 40 magnetron 40a duct 40b antenna 40c output portion 41 heater 42 infrared sensor 43 thermistor 43a detection portion 45 Control unit 50 Operation unit 50a LED
51 Operation unit 52 Operation unit 54 Liquid crystal panel (display unit)
54a Number display section (display area)
56 Menu board 56a Board body 56b Notch 56c Elastic piece 56d Grip 56e Standing part 56f Protrusion 56g Hook 56h Ventilation hole 57 Menu 58 Number 59 QR code (two-dimensional code)
60 Plate 60a Main body 60b Flange portion 61 Cushioning member 62 Hanging rail 65 Container 65a Bottom wall portion 65b Side wall portion 65c Flange portion 66 Cushioning member 68 Air intake hole 69 Exhaust hole 70 Fan 71 Fan case 72 Case main body 72a Air outlet 73 Cover 73a Air intake port 75 Power supply board 76 Board case 76a Vent 78 Inverter 79 Inverter case 80 Case main body 80a Intake port 80b Air outlet 81 Cover

Claims (5)

An exterior body;
a heating chamber provided in the exterior body for heating food by microwaves;
an arrangement portion formed between the exterior body and the heating chamber, in which an electric component is arranged;
a menu board on which a predetermined number of menus are displayed, the menu board being attached to the exterior body so as to be movable between a use position in which the plurality of menus are exposed from the exterior body and a non-use position in which the plurality of menus are covered by the exterior body;
a display unit capable of selectively displaying the plurality of menus;
an operation unit that is capable of changing the menu displayed on the display unit and that is used to select one of the plurality of menus,
the exterior body is provided with an air intake hole for drawing air outside the placement section into the interior,
The microwave oven, wherein the menu board is provided with a vent hole that communicates with the intake hole when the microwave oven is in the non-use position. a door attached to the exterior body so as to be openable and closable, and configured to close an opening of the heating chamber;
The menu board is disposed on the bottom side of the exterior body,
The air vent is disposed at the end of the menu board on the door side.
2. The microwave oven according to claim 1. the electrical component includes a fan for drawing air outside the placement unit into the interior and discharging air inside the placement unit to the exterior;
an exhaust hole for discharging air from the arrangement section to the outside is provided on a downstream side of the airflow generated by the fan in the arrangement section;
The electrical components include a power supply board, an inverter, and a microwave source, which are arranged in this order from the intake hole to the exhaust hole.
3. The microwave oven according to claim 1 or 2. The microwave oven of claim 1 or 2, wherein the vent hole and the intake hole extend in directions that intersect with each other. The microwave oven of claim 1 or 2, wherein the menu board displays a two-dimensional code for referencing heating settings for menus other than the plurality of menus.