Patent Description:
A door covering a front opening of a heating chamber of a cooker is at least partially made of a transparent member such as glass. This allows a user to visually check an inside of the heating chamber (see, for example, Patent Literature <NUM>).

Patent Literature <NUM> discloses a cooker including a door having an upper-side door frame and a lower-side door frame. Each of the upper-side door frame and the lower-side door frame includes an outer barrier, an inner barrier, and a cutout. The outer barrier faces the inner barrier with an inside space interposed therebetween. The cutout supports the outer barrier and the inner barrier from above and below, and communicates the outside with a space in the door.

<CIT> discloses a cooker with outlet openings which correspond with inlet openings on a door to enable an air flow to enter the door (cf.

<CIT>, <CIT> and <CIT> are further examples of prior art related with the application.

A cooker disclosed in Patent Literature <NUM> intends to improve performance of suppressing occurrence of fogging, that is, dew condensation in a space between an outer barrier and an inner barrier. Specifically, a cooker disclosed in Patent Literature <NUM> has a water-preventing wall disposed in an inner side of the cutout provided in a lower-side door frame and being close to the space. This water-preventing wall has a height higher than a thickness of the outer barrier.

The present disclosure provides technology for further suppressing occurrence of fogging in a space in a door of a cooker.

The present invention is defined by the independent claim. Further embodiments of the present invention are described in the dependent claims.

The cooker of the present disclosure can suppress occurrence of fogging in a space in the door.

Hereinafter, the exemplary embodiment is described in detail with reference to drawings. However, a more detailed description than necessary may be omitted. For example, a detailed description of already-known matter, or repeated description of substantially the same configurations may be omitted.

The attached drawings and the following description are provided for a person skilled in the art to sufficiently understand the present disclosure, but are not intended to limit the subject matter described in claims.

<FIG> show an appearance of cooker <NUM> in accordance with one exemplary embodiment of the present disclosure. <FIG> is a front perspective view of cooker <NUM> in a state in which door <NUM> is closed. <FIG> is a front perspective view of cooker <NUM> in a state in which door <NUM> and operation panel <NUM> are removed.

In <FIG>, the front side of each drawing corresponds to the front of cooker <NUM>. In other words, a door <NUM> side and a front opening 3b side of cooker <NUM> are defined as the front, and a side opposite to the front (a deep side in <FIG>) is defined as the rear. The left side and the right side in <FIG> are defined as the left side and the right side of cooker <NUM>, respectively.

As shown in <FIG>, cooker <NUM> includes housing <NUM>, heating chamber <NUM>, door <NUM>, machine chamber <NUM>, and operation panel <NUM>. Heating chamber <NUM> is disposed in housing <NUM>. Door <NUM> covers front opening 3b that is a front surface of housing <NUM> and is surrounded by front frame 3a. Machine chamber <NUM> is disposed in housing <NUM> and is adjacent to the right side of heating chamber <NUM>. Operation panel <NUM> is disposed on the front surface of machine chamber <NUM>.

Machine chamber <NUM> includes a microwave oscillator for generating microwaves. In this exemplary embodiment, the microwave oscillator is, for example, magnetron <NUM>.

Heating chamber <NUM> has a microwave radiation port (not shown) for radiating microwaves generated by magnetron <NUM> into heating chamber <NUM>. A heating target (food) placed in heating chamber <NUM> is heated by microwaves radiated from the microwave radiation port.

Inside of housing <NUM> and at the rear of a rear wall of heating chamber <NUM>, a convection heater unit (not shown) is disposed. The convection heater unit includes a convection heater and a circulation fan.

For heating by the convection heater unit, a suction hole and a discharge hole (both are not shown) are formed on the rear wall of heating chamber <NUM>. When the circulation fan is driven to rotate, air in heating chamber <NUM> is sucked through the suction hole. The air is heated by the convection heater, and is returned to heating chamber <NUM> through the discharge hole. Thus, the heating target is uniformly heated. On the front lower part of housing <NUM>, a suction port (not shown) for sucking outside air into housing <NUM> is provided.

Magnetron <NUM> and the convection heater unit are heating devices of cooker <NUM>.

Door <NUM> includes a horizontal rotation axis disposed below the front surface of housing <NUM>, and is attached so as to cover front opening 3b of housing <NUM>. Door <NUM> has handle 7a attached to the front upper part of door <NUM> by attachment part 7aa (see <FIG>). When handle 7a is pulled to rotate door <NUM> around the rotation axis, front opening 3b is opened. When door <NUM> is lifted with handle 7a and is rotated until door <NUM> is in a vertical state, front opening 3b is closed.

Operation panel <NUM> includes a display and an operation part. The display is, for example, a liquid crystal screen for displaying a menu screen and the like. The operation part includes, for example, push buttons or a dial, and receives instructions from a user to cooker <NUM>.

Machine chamber <NUM> includes fan <NUM>, magnetron <NUM>, a convection heater unit, a control board (not shown), and the like. Fan <NUM> sends cooling air for cooling magnetron <NUM>, the convection heater unit, a control board, and the like. The control board has the controller, an inverter circuit, and the like.

The controller includes a microprocessor and a semiconductor memory. The controller is connected to operation panel <NUM>, fan <NUM>, the convection heater unit, the inverter circuit, and the like. The controller receives instructions input through the operation part of operation panel <NUM>, and controls the display of operation panel <NUM>, fan <NUM>, the convection heater unit, the inverter circuit, and the like. The inverter circuit drives magnetron <NUM>.

Cooker <NUM> includes door arm attachment hole <NUM>, door arm <NUM>, hinge attachment hole <NUM>, and hinge <NUM>.

Door arm <NUM> includes first door arm 19a and second door arm 19b, is linked to door <NUM>, and regulates an opening degree of door <NUM>. Hinge <NUM> includes first hinge 24a and second hinge 24b having a common horizontal rotation axis, and links door <NUM> to housing <NUM> rotatably.

Door arm attachment hole <NUM> includes first door arm attachment hole 17a and second door arm attachment hole 17b. Hinge attachment hole <NUM> includes first hinge attachment hole 22a and second hinge attachment hole 22b. In this exemplary embodiment, door arm attachment hole <NUM> and hinge attachment hole <NUM> correspond to housing-side attachment holes.

First hinge attachment hole 22a is provided in a part of front frame 3a below front opening 3b at the right side. To first hinge attachment hole 22a, first hinge 24a is attached. First door arm attachment hole 17a is provided in a lower right part of front frame 3a and above first hinge attachment hole 22a.

The front end of first door arm 19a is attached to the rear surface at the right end of door <NUM>, and is rotatable around the horizontal rotation axis. First door arm 19a is supported by a guide roller (not shown) disposed inside housing <NUM> at the rear of first door arm attachment hole 17a. The rear end of first door arm 19a is linked to the inside of housing <NUM> at the rear of the guide roller through a spring (not shown).

Second hinge attachment hole 22b is provided in a part of front frame 3a below front opening 3b at the left side. To second hinge attachment hole 22b, second hinge 24b is attached. Second door arm attachment hole 17b is provided in a lower left part of front frame 3a and above second hinge attachment hole 22b.

The front end of second door arm 19b is attached to the rear surface at the left end of door <NUM>, and is rotatable around the horizontal rotation axis. Second door arm 19b is supported by a guide roller (not shown) disposed inside housing <NUM> at the rear of second door arm attachment hole 17b. The rear end of second door arm 19b is linked to the inside of housing <NUM> at the rear of the guide roller through a spring (not shown).

<FIG> show a configuration of door <NUM> of cooker <NUM> in accordance with this exemplary embodiment. <FIG> is a perspective view of door <NUM>. <FIG> is an exploded perspective view of door <NUM>.

As shown in <FIG>, door <NUM> includes handle 7a, member 7b, member 7c, member 7d, member 7e, outer screen 8a, and inner screen 8b. Members 7b, 7c, 7d, and 7e constitute outer frame of door <NUM>. Outer screen 8a and inner screen 8b are made of transparent glass, and cover an opening, surrounded by outer frames of door <NUM>, in the middle of door <NUM>.

Outer screen 8a is attached to attachment part 8c of member 7b. Inner screen 8b is attached to a rear side of member 7d. Space <NUM> in door <NUM> (see <FIG>) is defined by outer screen 8a, inner screen 8b, and the outer frame of door <NUM>.

Radio wave leakage prevention plate 7f is a metal plate disposed in space <NUM>. Radio wave leakage prevention plate 7f prevents radio waves from leaking to the outside of heating chamber <NUM> through door <NUM>. Radio wave leakage prevention plate 7f includes a large number of punching holes (not shown) provided in the middle of radio wave leakage prevention plate 7f facing front opening 3b.

A user can visually check the inside of heating chamber <NUM> from the front of cooker <NUM> through the punching hole, outer screen 8a, and inner screen 8b.

<FIG> is a rear view of member 7e constituting door <NUM>. As shown in <FIG>, member 7e includes door arm attachment hole <NUM> and hinge attachment hole <NUM> provided in the rear surface.

Door arm attachment hole <NUM> includes first door arm attachment hole 18a and second door arm attachment hole 18b. Hinge attachment hole <NUM> includes first hinge attachment hole 23a and second hinge attachment hole 23b. In this exemplary embodiment, door arm attachment hole <NUM> and hinge attachment hole <NUM> correspond to door-side attachment holes.

First hinge attachment hole 23a and second hinge attachment hole 23b are provided in the rear lower part of member 7e at the left end and the right end, respectively, in <FIG> (at the right end and left, respectively, in <FIG>). First door arm attachment hole 18a and second door arm attachment hole 18b are provided above first hinge attachment hole 23a and second hinge attachment hole 23b, respectively. In <FIG>, first door arm 19a and first hinge 24a are not shown.

When front opening 3b is covered with door <NUM>, first door arm attachment hole 17a faces first door arm attachment hole 18a, and second door arm attachment hole 17b faces second door arm attachment hole 18b. First hinge attachment hole 22a faces first hinge attachment hole 23a, and second hinge attachment hole 22b faces second hinge attachment hole 23b.

First door arm attachment hole 17a and first hinge attachment hole 22a communicate with machine chamber <NUM>. Therefore, air sent from fan <NUM> flows toward the outside of housing <NUM> though first door arm attachment hole 17a and first hinge attachment hole 22a. When door <NUM> covers front opening 3b, the air reaches to door <NUM>.

<FIG> is a rear view of member 7b constituting door <NUM>. Air intake port <NUM> is provided in the rear lower part of member 7b at the left end of <FIG> (the right end in <FIG>). The air flowing out to the outside of housing <NUM> is supplied to space <NUM> in door <NUM> through air intake port <NUM>. Thus, the water vapor that is present in space <NUM> in door <NUM> can be exhausted to the outside.

Air intake port <NUM> is provided in the vicinity of first door arm attachment hole 18a and first hinge attachment hole 23a, but is not provided in the vicinity of second door arm attachment hole 18b and second hinge attachment hole 23b.

<FIG> is a perspective view of door <NUM> as viewed obliquely from below in a state in which outer screen 8a is removed. <FIG> is a partially expanded view of a vicinity of an exhaust port of <FIG>.

As shown in <FIG>, door <NUM> includes vent hole <NUM> and exhaust port <NUM>. Vent hole <NUM> is provided in a part of member 7c defining the upper end of space <NUM> in door <NUM>. Exhaust port <NUM> is provided in a part of member 7b positioned above vent hole <NUM>. Vent hole <NUM> and exhaust port <NUM> are openings for exhausting air flowing upward and water vapor in space <NUM> to the outside of door <NUM>.

Vent hole <NUM> includes first vent hole 26a and second vent hole 26b. Exhaust port <NUM> includes first exhaust port 27a and second exhaust port 27b. First vent hole 26a and first exhaust port 27a are provided in the upper right part of door <NUM>. Second vent hole 26b and second exhaust port 27b are provided in the upper left part of door <NUM>.

As described above, air sent from fan <NUM> (see <FIG>) is sent to the outside of housing <NUM> through first door arm attachment hole 17a and first hinge attachment hole 22a (see <FIG>). The air is supplied to space <NUM> in door <NUM> through first door arm attachment hole 18a and first hinge attachment hole 23a of door <NUM> (see <FIG>), and air intake port <NUM> (see <FIG>).

<FIG> is a view schematically showing a flow of air in space <NUM> inside door <NUM>. As shown in <FIG>, the air supplied to space <NUM> generates an upward air flow in the entire area of the space <NUM>.

Air intake port <NUM> is provided only in the right side (the left side in <FIG>) of the lower part of door <NUM>. Therefore, as shown by arrows in <FIG>, mainly two air flows are generated in space <NUM>. A first flow is an air flow from air intake port <NUM> to first exhaust port 27a positioned above air intake port <NUM>. A second flow is an air flow from air intake port <NUM> to second exhaust port 27b positioned obliquely above air intake port <NUM>.

When the temperature of space <NUM> is low, few air flows are generated in the lower left part of space <NUM>. When cooker <NUM> is operated and the air in space <NUM> is heated, an air flow upward from the lower left part in space <NUM> is generated. Thus, an air flow from air intake port <NUM> to the lower left part of space <NUM> is generated. As a result, water vapor that is present in the entire part of space <NUM> can be efficiently exhausted to the outside of door <NUM>.

In this exemplary embodiment, air is supplied to the inside of space <NUM> for efficiently exhausting water vapor in space <NUM> rather than for cooling outer screen 8a of door <NUM>. Therefore, it is sufficient to provide air intake port <NUM> only in a part of the lower part of space <NUM>, and it is not necessary to provide air intake port <NUM> over the entire part of the lower part of space <NUM>.

The outer periphery of space <NUM>, excluding air intake port <NUM> and exhaust port <NUM>, may be sealed. Thus, even if a user spills liquid in the vicinity of door <NUM> or boils water in the vicinity of cooker <NUM>, it is possible to suppress entering of foreign matter such as liquid or water vapor into space <NUM>. If most of the outer periphery of space <NUM> is sealed, occurrence of dew condensation in space <NUM> can be suppressed.

In this exemplary embodiment, air intake port <NUM> is provided in the lower part of door <NUM>, and exhaust port <NUM> is provided below attachment part 7aa of handle 7a. This can suppress entering of foreign matter such as liquid and water vapor from air intake port <NUM> or exhaust port <NUM>.

Air intake port <NUM> and exhaust port <NUM> are provided in not the entire part but only a part of the upper part or the lower part of door <NUM>. This can suppress entering of foreign matter from intake port <NUM> or exhaust port <NUM>.

Hereinafter, operations and actions of cooker <NUM> configured as mentioned above are described.

A user places a heating target in heating chamber <NUM>, closes door <NUM>, operates operation panel <NUM> to set heating conditions such as heating time and a heating temperature. A controller (not shown) of cooker <NUM> controls magnetron <NUM> or the like so that the heating target is heated under the set heating conditions.

While magnetron <NUM> works, fan <NUM> is driven, air is sent toward magnetron <NUM>, a control board, or the like. The air from fan <NUM> is supplied to space <NUM> in door <NUM> through hinge attachment hole <NUM> and door arm attachment hole <NUM> of housing <NUM>, hinge attachment hole <NUM> and door arm attachment hole <NUM> of door <NUM>, and air intake port <NUM>. The air supplied to space <NUM> is exhausted to the outside, together with water vapor that is present in space <NUM>, through exhaust port <NUM> provided in the upper part of door <NUM>.

Thus, water vapor that is present in space <NUM> can be efficiently exhausted to the outside. As a result, occurrence of dew condensation in space <NUM> can be suppressed. Even if dew condensation temporarily occurs in space <NUM>, water vapor can be quickly exhausted to the outside to remove dew condensation.

According to this exemplary embodiment, water vapor can be exhausted more efficiently than a case where water vapor in space <NUM> is exhausted only by natural convection through air intake port <NUM> and exhaust port <NUM> provided in space <NUM>. Therefore, occurrence of dew condensation in space <NUM> can be suppressed more effectively.

A more moderate air flow can be generated than a case where air is sent into space <NUM> by a special-purpose fan or the like provided in the vicinity of space <NUM>. Therefore, it is possible to suppress excessively cooling of door <NUM> to affect heating in heating chamber <NUM>.

This exemplary embodiment uses, as a fan for sending air to space <NUM>, fan <NUM> for cooling electronic components such as magnetron <NUM> and a control board. Thus, occurrence of dew condensation in space <NUM> can be suppressed without adding a special-purpose fan or the like. As a result, an increase of the manufacturing cost of cooker <NUM> can be suppressed.

In this exemplary embodiment, as an air passage through which air is sent from machine chamber <NUM> to door <NUM>, a housing-side attachment hole and a door-side attachment hole are used. Thus, air can be supplied into space <NUM> without adding a special-purpose air passage. As a result, an increase in the manufacturing cost of cooker <NUM> can be suppressed.

As mentioned above, in this exemplary embodiment, a cooker includes a housing, a heating chamber, a door, at least one heating device, a control board, a machine chamber, and a fan.

The heating chamber is disposed inside the housing and has a front opening. The door covers the front opening. The control board is connected to the at least one heating device. The machine chamber is disposed inside the housing and includes the controller. The fan is housed in the machine chamber and sends air toward the machine chamber.

The door has an outer frame, two members covering an opening surrounded by the outer frame, and an air intake port and an exhaust port provided in the outer frame. The air intake port is provided in the lower part of the door and close to the machine chamber.

Thus, water vapor that is present in a space in the door can be exhausted efficiently. As a result, occurrence of dew condensation in the space can be suppressed. During heating, the progress of cooking in the heating chamber can be always checked visually through a screen disposed in the door.

In this exemplary embodiment, the exhaust port is provided in a part of the upper part of the door. Thus, together with heated air, water vapor that is present in the space in the door can be efficiently exhausted. As a result, occurrence of fogging in the space in the door can be effectively suppressed.

In this exemplary embodiment, the door has a handle attached to the upper part of the door by an attachment part. The exhaust port is provided below the attachment part of the handle. Thus, entering of foreign matter such as liquid and water vapor from the exhaust port to a space in the door can be suppressed.

According to the invention, the cooker further includes a door arm linking the door to the housing. The door has a door-side attachment hole to which the front end of the door arm is attached. The housing has a housing-side attachment hole to which the rear end of the door arm is attached. The machine chamber communicates with the inside of the door defined by the outer frame and the two members through the housing-side attachment hole, the air intake port, and the door-side attachment hole.

This configuration does not require a special-purpose air passage for supplying the air sent from the fan to the space in the door. As a result, an increase in manufacturing cost of the cooker can be suppressed.

The above exemplary embodiment is an example of the technology in accordance with the present disclosure, and the technology in accordance with the present disclosure is not limited to the above exemplary embodiment. The technology in accordance with the exemplary embodiment includes modified examples with modifications, substitutions, additions, omissions, and the like, applied to the above-described exemplary embodiment.

Hereinafter, a modified example of the above exemplary embodiment is described below.

The cooker of the above exemplary embodiment includes a microwave and a convection heater unit as a heating device. However, the cooker of the present disclosure is not limited to this configuration.

The cooker of the present disclosure may further include, as a heating device, a radiation heater disposed on the ceiling of heating chamber <NUM> in housing <NUM> and radiation-heating a heating target from above. The cooker of the present disclosure may further include, as a heating device, a steam generator disposed in machine chamber <NUM> and heating the heating target by supplying heating chamber <NUM> with high temperature steam. The cooker of the present disclosure may include at least one of the plurality of heating devices.

In cooker <NUM> of the above-mentioned exemplary embodiment, machine chamber <NUM> is disposed at the right side with respect to heating chamber <NUM>. However, machine chamber <NUM> may be disposed at the left side with respect to heating chamber <NUM>. In this case, air intake port <NUM> is disposed at the left side of door <NUM>.

Claim 1:
A cooker (<NUM>) comprising:
a housing (<NUM>);
a heating chamber (<NUM>) disposed inside the housing (<NUM>), and having a front opening (3b);
a door (<NUM>) covering the front opening (3b);
at least one heating device (<NUM>);
a control board including a controller connected to the at least one heating device (<NUM>);
a machine chamber (<NUM>) disposed inside the housing (<NUM>), and housing the controller; and
a fan (<NUM>) housed in the machine chamber (<NUM>) and sending air toward the machine chamber (<NUM>),
wherein the door (<NUM>) includes an outer frame (7b, 7c, 7d, 7e), two members (8a, 8b) covering an opening surrounded by the outer frame (7b, 7c, 7d, 7e), an air intake port (<NUM>) and an exhaust port (<NUM>) each provided in the outer frame (7b, 7c, 7d, 7e),
the air intake port (<NUM>) is provided in a lower part of the door (<NUM>) and close to the machine chamber (<NUM>),
the cooker (<NUM>) further comprises a door arm (19a) linking the door (<NUM>) to the housing (<NUM>),
the door (<NUM>) has a door-side attachment hole (18a, 23a) to which a front end of the door arm (19a) is attached,
the housing (<NUM>) has a housing-side attachment hole (17a, 22a) to which a rear end of the door arm (19a) is attached, and
the machine chamber (<NUM>) communicates with an inside of the door (<NUM>) defined by the outer frame (7b, 7c, 7d, 7e) and the two members (8a, 8b) through the housing-side attachment hole (17a, 22a), the air intake port (<NUM>), and the door-side attachment hole (18a, 23a).