WO2008032898A1

WO2008032898A1 - Cooking apparatus

Info

Publication number: WO2008032898A1
Application number: PCT/KR2006/005287
Authority: WO
Inventors: Keun-Jae Hwang
Original assignee: Lg Electronics, Inc.
Priority date: 2006-09-12
Filing date: 2006-12-07
Publication date: 2008-03-20
Also published as: EP2064492A4; RU2009113626A; CN101512231B; KR20080024022A; EP2064492A1; RU2424471C2; EP2064492B1; CN101512231A; MX2009002671A

Abstract

In order to provide a cooking apparatus capable of preventing heat generated from a cooking cavity from being transferred to the outside of a door or to a handle, the present invention discloses a cooking apparatus, comprising: a cooking cavity; and, a door opening and closing the cooking cavity and including a front plate, a door frame located at the rear of the front plate to block microwaves and a middle plate located between the front plate and the door frame to block heat transferred from the cooking cavity to the front plate.

Description

COOKING APPARATUS

Technical Field

[1] The present invention relates in general to a cooking apparatus, more specifically, to a cooking apparatus provided with a middle plate for blocking heat transfer from a cooking cavity to the outside of a door or to a handle. Background Art

[2] Korean Patent Application Laid-Open No. 2005-0083504 discloses a typical example of a cooking apparatus that has major components inclusive of a magnetron, a high voltage transformer, a high voltage capacitor, and a cooling fan provided at one side of a cooking cavity. Korean Patent Application Laid-Open No. 2006-0037003 discloses a cooking apparatus that has major components inclusive of a magnetron, a high voltage transformer, and a high voltage capacitor installed at the upper side of a cooking cavity and accommodates a convection heater assembly at the rear wall of the cooking cavity. Korean Utility Model Application Laid-Open No. 1999-0010444 discloses a cooking apparatus that has major components inclusive of a magnetron, a high voltage transformer, and a cooling fan and an operating panel provided at the lower side of a cooking cavity.

[3] In addition, Korean Utility Model Application Laid-Open No. 1998-0016489 discloses a cooking apparatus, which has major components inclusive of a magnetron, a high voltage transformer and a cooling fan installed at a side wall of a cooking cavity and which is provided with a cooling flow path starting from the upper wall of the cooking cavity to a lateral side thereof.

[4] Korean Patent Application Laid-Open No. 1998-0053939 discloses a door of a microwave oven used as a typical example of cooking apparatuses, in which the door is provided with a door frame for blocking microwaves and a choke cover surrounding the door frame.

[5] Korean Patent Application Laid-Open No. 1995-0003729 discloses a cooking apparatus that has a cooking flow path starting from a lateral side of a cooking cavity, going via the bottom side of the cooking cavity, to the door.

[6] Korean Patent Application Laid-Open No. 2004-0108050 discloses an example of an operating panel for use in a cooking apparatus, in which the operating panel is provided with a glass-touch keyboard using static electricity. Disclosure of Invention Technical Problem

[7] It is an object of the present invention to provide a cooking apparatus capable of preventing heat generated from a cooking cavity from being transferred to the outside of a door or to a handle. [8] Another object of the present invention is to provide a cooking apparatus capable of cooling the inside of a door using air flow and a stagnant air layer. [9] Still another object of the present invention is to provide a cooking apparatus capable of cooling the inside of a door using air flow generated from the rear space of the cooking apparatus. [10] Still another object of the present invention is to provide a cooking apparatus provided with a door that is built for enabling a user to see the inside of a cooking cavity, and capable of blocking heat transfer to the outside of the door or to the handle. [11] Still another object of the present invention is to provide a cooking apparatus capable of preventing heat generated from a cooking cavity from being transferred to a control panel provided to a door. [12] Yet another object of the present invention is to provide a cooking apparatus, which forms a cooling flow path from a cooking cavity towards a door and which is capable of preventing foreign substances from getting inside the door through the cooling flow path.

Technical Solution [13] To achieve the above objects and advantages, there is provided a cooking apparatus, comprising: a cooking cavity; and, a door opening and closing the cooking cavity and including a front plate, a door frame located at the rear of the front plate to block microwaves and a middle plate located between the front plate and the door frame to block heat transferred from the cooking cavity to the front plate. [14] In another aspect of the present invention, the cooking apparatus comprises a flow path formed to pass by at least one of the outer surfaces of the cooking cavity, and the door is provided with an opening for communication with the flow path. [15] In another aspect of the present invention, the flow path is extended from the rear of the cooking cavity to the upper portion of the cooking cavity, and the opening is formed at the upper portion of the door to communicate with the flow path. [16] In another aspect of the present invention, the door is provided with a door flow path formed in a way that a flow coming out of the opening passes by at least one of the lateral surfaces of the middle plate. [17] In another aspect of the present invention, the door flow path is formed in a way that the flow coming out of the opening passes between the front plate and the middle plate. [18] In another aspect of the present invention, the door is provided with a bracket for guiding the flow coming out of the opening towards the at least one of the lateral surfaces of the middle plate.

[19] In another aspect of the present invention, the bracket is located over the middle plate.

[20] In another aspect of the present invention, the opening is provided with means for preventing foreign substances from getting inside the door.

[21] In another aspect of the present invention, there is provided a cooking apparatus, comprising: a cooking cavity; and, a door opening and closing the cooking cavity and including a door panel provided with an opening for enabling a user to see the inside of the cooking cavity; and a middle plate located on the opening of the door panel to block heat generated from the cooking cavity.

[22] In another aspect of the present invention, the middle plate is made of a material that enables a user to see the inside of the cooking cavity.

[23] In another aspect of the present invention, the door is provided with a front plate mounted on the door panel to cover at least the opening and made of a material for a user to be able to see the inside of the cooking cavity through the opening of the door panel, and a door frame mounted on the door panel to block microwaves from the cooking cavity and having a part made of a material for a user to be able to see the inside of the cooking cavity through the opening of the door panel.

[24] In another aspect of the present invention, the door includes a choke cover located at the rear of the door frame and provided with a first opening for passing a flow into the door, and a second opening formed to allow a user to see the inside of the cooking cavity.

[25] In another aspect of the present invention, the door is provided with a door flow path formed to pass by at least one of the lateral surfaces of the middle plate.

[26] In another aspect of the present invention, the door is provided with a front plate mounted on the door panel to cover at least the opening; and a door flow path formed to pass between the front plate and the middle plate.

[27] In another aspect of the present invention, the door is provided with a control panel located at the upper portion of the opening of the door panel.

[28] In another aspect of the present invention, there is provided a cooking apparatus comprising: a cooking cavity carrying out a cooking process using microwaves; a door opening and closing the cooking cavity and provided with a door frame blocking the microwaves; a flow path extended from the cooking cavity side to the door side for a flow to pass thereon; and a choke cover formed at the door and provided with a first opening communicating with the flow path of the cooking cavity side and preventing foreign substances from getting into the door, and a second opening formed to expose the door frame.

[29] In another aspect of the present invention, the cooking apparatus further comprises a door panel mounting the door frame and provided with an opening formed for the flow to pass therethrough.

[30] In another aspect of the present invention, the cooking apparatus further comprises a middle plate located on the opening and blocking heat generated from the cooking cavity.

[31] In another aspect of the present invention, the choke cover is formed in a way that the choke cover of the first opening side and the choke cover of the second opening side are separately made.

[32] In another aspect of the present invention, there is provided with a cooking apparatus, comprising: a cooking cavity carrying out a cooking process using microwaves; a door opening and closing the cooking cavity and provided with a door frame to block the microwaves; a flow path extended from the cooking cavity side to the door side for a flow to pass thereon; a door panel mounting the door frame and provided with an opening formed for the flow to pass therethrough; a middle plate located on the opening and blocking heat generated from the cooking cavity; and, a choke cover formed at the door and provided with a first opening communicating with the flow path of the cooking cavity side, and a second opening formed to expose the door frame; wherein the middle plate, the door frame, and the choke cover are mounted on the door panel for the flow to form a flow path of the door side passing from the first opening of the choke cover, via the upper portion of the door frame, through at least one of the lateral surfaces of the middle plate.

[33] Additional and/or other aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention. Brief Description of the Drawings

[34] The above aspects and features of the present invention will be more apparent by describing certain embodiments of the present invention with reference to the accompanying drawings, in which:

[35] FlG. 1 is an exploded schematic view of the main structure of a cooking apparatus according to the present invention;

[36] FlG. 2 schematically shows an example of the rear space of a cooking apparatus according to the present invention;

[37] FIGS. 3 and 4 schematically show other examples of the rear space of a cooking apparatus according to the present invention;

[38] FIGS. 5 and 6 schematically show a cooling flow path according to the present invention; and

[39] FIGS. 7 through 9 schematically show an example of a door according to the present invention.

Mode for the Invention

[40] The present invention will be described in detail herein below with reference to the accompanying drawings.

[41] FlG. 1 is an exploded schematic view of the main structure of a cooking apparatus in accordance with the present invention, showing a cooking cavity 100, a door 200, an upper space 300 located over the cooking cavity 100, a rear space 400 located at the rear of the cooking cavity 100, lateral spaces 500 located on both sides of the cooking cavity 100, and a lower space 600 located under the cooking cavity 100.

[42] The cooking cavity 100 is a space for cooking food, and is defined by an inner case

110. A heater 120 is provided at the upper portion of the inside of the cooking cavity 100, and a plate or a rack 130 is placed inside the cooking cavity 100. The inner case 110 includes an inlet (not shown) and an outlet 111 formed on the sides for forming an air flow path to remove heat and smell inside the cooking cavity 100. An example of the heater 120 is a sheath heater. The use of the plate 130 in replacement of a circular turn table brings change to width and length (depth) of the cooking cavity 100, the modification of which is restricted by the turn table. At one side of the cooking cavity 100 is provided a guide 140 for guiding the plate 130. In addition, at the front and rear sides of the cooking cavity 100 are provided a front frame 150 and a rear frame 160, respectively, and the front frame 150 has an opening 151 for forming a flow path between the upper space 300 and the door 200. The rear frame 160 also has an opening 161 formed at the upper side for communication with the rear space 400.

[43] The lower portion of the door 200 is hinged to the cooking cavity 100 so that the door 200 can open and close the cooking cavity 100. The door 200 is formed to cover the cooking cavity 100 and the upper space 200. The door 200 is composed of a handle 210, a front plate 220, an input sensing unit 230, a door panel 240, a control panel 250, a middle plate 260, a bracket 270, a door frame 280, and a choke cover 290.

[44] The handle 210 is a part that a user uses to open or close the door 200, and can be fixed to the front plate 220 by bolts (not shown). Desirably, the handle 210 has at least one channel (not shown) formed inside along its longitudinal direction in a manner that the channel is communicated with outside, so that the total weight can be reduced and the amount of heat transferred to the user from the cooking cavity 100 during cooking can be minimized.

[45] The front plate 220 is desirably made of a transparent glass for the user to be able to see the inside of the cooking cavity 100, and a display unit (not shown) including buttons may be attached or coated thereto, the buttons being used for the user to select a cooking course or for the indication of an operating status of the cooking apparatus. [46] The input sensing unit 230 is a part that recognizes which button is selected by the user. In the case that the input sensing unit 230 is located at the rear of the front plate 220 made of glass, it can be composed of a glass touch unit and serve as an electrostatic sensor. The glass touch unit can be attached to the front plate 220 using a tape. The input sensing unit 230 is located at the upper region of the door 200 facing the upper space 300 of the cooking cavity 100, and this structure ensures a broader cooking cavity and helps the user easily see the inside of the cooking cavity 100 without hindrance.

[47] The door panel 240 is a part that fixes other components 220, 250 and the like of the door 200, and has an opening 241 for the user to see the inside of the cooking cavity 100. Moreover, the door panel 240 has in its lower side an outlet (not shown) through which the flow traveling along a cooling flow path extended from a cooling fan 420 (to be described) to the door 200 via the upper space 300 is discharged.

[48] The control panel 250 is a part for controlling the overall operation of the cooking apparatus according to a user input. To this end, it cooperates with the input sensing unit 230 and a relay substrate 350 (to be described), and is fixed to the door panel 240 from the rear side of the input sensing unit 230. Desirably, the control panel 250 is provided with a light-emitting source such as an LED (light emitting diode), and irradiates the light emitted from the light-emitting source to the display unit (not shown).

[49] The middle plate 260 is a part fixed to the door panel 240, while being spaced out from the front plate 220 and the door frame 280, respectively. Its primary function is to block heat transfer from the cooking cavity 100 to the front frame 220 and the handle 210. Desirably, the middle plate 260 is installed at the door panel 240 so that a flow generated from the cooling fan 420 (to be described) enters the door 200 via the rear space 400 and the upper space 300 and then travels between the middle plate 260 and the front plate 220 under the guidance of a bracket 270 (to be described). Such a flow vents through the outlet (not shown) of the door panel 240.

[50] The bracket 270 is fixed to the door panel 240 from the rear side of the control panel 250. It serves to protect the input sensing unit 230 and the control panel 250, each including electronic components, against heat and microwaves from the cooking cavity 100 and against the flow by the cooling fan 420, and guides the flow to travel between the door panel 240 and the front plate 220.

[51] The door frame 280 is accommodated in the door panel 240, and serves to block leakage of microwaves to the outside of the cooking apparatus.

[52] The choke cover 290 is a cover for the door 200 located towards the cooking cavity

100, and has an opening 291 formed on its upper side in correspondence to the opening 151 of the front frame 150. The opening 291 is preferably composed of tiny holes in order to prevent food or foreign substances from getting into the door 200 while the door 200 is being open.

[53] The upper space 300 is a space over the cooking cavity 100 defined by an external case 310, and includes a heater 320, a waveguide 330, an insulating upper plate 340, and a relay substrate 350. Optionally, a lamp (not shown) for lightening the cooking cavity 100 may be provided as well.

[54] The external case 310 has a shape that encompasses the top and both sides of the cooking cavity 100 at a distance away, and is connected to the front frame 150 and the rear frame 160. If necessary, it may have an outlet 311 so that a flow having traveled around the cooking cavity 100 and the heating elements installed in the cooking apparatus can be vented to the outside.

[55] An example of the heater 320 is a halogen heater. Since such a heater 320 is influenced by microwaves, unlike the heater 120 formed of a sheath heater, the heater 320 is installed at the upper side of the inner case 110 so as to provide heat downwardly into the cooking cavity 100 from above.

[56] The waveguide 330 is extended from the rear space 400 to the upper space 300, and serves to provide microwaves generated from a magnetron (not shown) to the cooking cavity 100. To do this, at the upper surface of the cooking cavity 100 is provided a port 331 (see FlG. 2).

[57] The insulating upper plate 340 prevents heat generated by the heater 120 housed in the inner case 110 from transferring to the upper space 300, and has a shape that covers the upper portion of the cooking cavity 100 except for the heater 320 and the waveguide 330.

[58] The relay substrate 350 is mounted on the insulating upper plate 340 from one side of the upper space 300, and interworks with the control panel 250 to operate components inclusive of the magnetron (to be described) placed at the rear space 400.

[59] FlG. 2 schematically shows an example of the rear space of a cooking apparatus according to the present invention. Referring to FIGS. 1 and 2, the rear space 400 is a space behind the cooking cavity 100 defined by the cover 410, and includes a cooling fan 420, a convection heater assembly 430, and heating elements such as a magnetron 440, a high voltage transformer 450, and a high voltage capacitor 460, together building a component room of the cooking apparatus.

[60] The cover 410 is connected to the rear frame 160 or the outer case 310 so as to cover the upper space 300 and the rear space 400, and its lower portion is connected to a base 610. At the lower portion of the cover 410 or the base 610 is provided an inlet 411 for air inflow to the cooling fan 420.

[61] The cooling fan 420 is located at the lower portion of the rear space 400 along the width direction thereof, and includes flow-generating units 421 and 422 on both sides to cool the components installed at the upper side. As the rear space 400, the upper space 300 and the door 200 are built in a way to be communicated, the entire area of the cooking apparatus can be cooled by means of the cooling fan 420. In addition, the cooling fan 420 is provided with a partition wall 423 for preventing the flow generated by the cooling fan 420 from flowing back to the cooling fan 420. The partition wall 423 has openings 424 and 425 formed on both sides in a manner to make the flow go up to the upper portion of the rear space 400. At the space 426 between the flow- generating units 421 and 422 is provided a motor (not shown) for driving the flow- generating units 421 and 422.

[62] FIGS. 3 and 4 schematically show other application examples of the rear space of a cooking apparatus according to the present invention. Referring to FIGS. 1-4, the rear space is provided, in addition to the structure shown in FlG. 2, with a flow guide 441 for guiding air flow to the magnetron 440, and a flow guide 442 for guiding the air flow coming out of the magnetron 440 to the inlet 112 that is formed on the lateral face of the cooking cavity 100. This structure, especially the flow guide 442, makes it possible to guide the air flow generated from the cooling fan 420 into the cooking cavity 100 stably and efficiently, and to effectively cool the magnetron, one of core components.

[63] The convection heater assembly 430 includes a fan 431, a heater 432, an inner heater cover 433, an outer heater cover 434, and a motor 435. Desirably, a heat insulating material (not shown) is placed between the inner heater cover 433 and the outer heater cover 434. Such a convection heater assembly 430 must have the motor 435. Since the motor 435 is installed being protruded backwardly from the rear space 400, the rear space 400 must have a room that is deep enough at least to accommodate the motor 435. Based on the attention to this space, such a large volume component 440, 450, and/or 460 among the major components used in the operation of the cooking apparatus can be placed in the rear space 400. In this way, even though part of the cooking cavity 100 in the longitudinal direction is sacrificed, the cooking cavity 100 is expanded in the lateral and vertical directions. Also, by using a plate instead of a turntable, a cooking apparatus according to the present invention can change the height, width and depth of the cooking cavity 100. Also, by placing the cooling fan 420 at the lower portion of the rear space 400, a cooking apparatus according to the present invention can utilize the rear space 400 and can cool the heating elements 440, 450, and/or 460 as well. Also, by providing the cooling fan 420 at the lower portion of the rear space 400 and building the rear space 400, the upper space 300, the door 200, the cooking cavity 100, and the lateral spaces 500 to be communicated with one another, the whole part of a cooking apparatus according to the present invention can be effectively cooled by the cooling fan 420. Also, as the cooling fan 420 is installed along the width direction of the rear space 400, the heating elements such as the convection heater assembly 430, the magnetron 440, the high voltage transformer 450, and the high voltage capacitor 460, which are provided in the rear space 400, can be cooled effectively, the flow can be traveled to the upper space 300, the lateral spaces 500 and the cooking cavity 100 and be vented through an outlet 611 formed on the base at the lower portion of the cooking cavity 100. Also, by providing the partition wall 423 and the openings 424 and 425, a cooking apparatus according to the present invention can form the flow path and flow and cool the heating elements, effectively and selectively. Also, the rear frame 160 may further comprise an opening 162 for communicating the lateral space 500. The opening 162 enables a direct air flow from the rear space 400 to the lateral space 500 and creates air flow to both sides of the rear space 400, thereby promoting the cooling process and the air flow onto both sides of the rear space 400.

[64] The magnetron 440, the high voltage transformer 450, and the high voltage capacitor 460 are major components used in the operation of the cooking apparatus, each generating a lot of heat. The magnetron 440 is placed above the opening 424, while the high voltage transformer 450 and the high voltage capacitor 460 are placed above the opening 425. The arrangement of these heating elements can be changed.

[65] The lateral spaces 500 are spaces on both sides of the cooking cavity 100 defined by the outer case 100, and they desirably communicate with the upper space 300, the rear space 400, and the lower space 600, and also with the cooking cavity 100 through the inlet 112 and the outlet 111. The flow generated from the cooling fan 420 travels from the rear space 400, the upper space 300, the cooking cavity 100, the lateral spaces 500, and eventually to the lower space 600. At this time, the flow traveling the upper space 300 and heading to the lateral space 500 can guide the flow that came out of the cooking cavity 100 through the outlet 111 to the lower space 600.

[66] The lower space 600 is a space below the cooking cavity 100 defined by the base

610. The base 610 is connected to the front frame 150 and the rear frame 160 to support the cooking apparatus, and includes the outlet 611 so as to exhaust the flow originated from the cooling fan 420 and the smell and heat generated in the cooking cavity 100. Even though the lower space 600 is defined by the rear frame 160 from the rear side, the base 610 is connected to the cover 410 over the rear frame 160. Therefore, the base 610 also functions as a member for limiting the lower portion of the rear space 400. The location of the outlet 611 is not particularly limited, so it can be on the side of the outlet 111, or preferably at the center of the base 610 to give a sufficiently long flow path. Since hot air flow is vented through the outlet 611, the cooking apparatus should not be placed on a kitchen appliance that is sensitive to heat. To protect such a kitchen appliance from any damages due to overheated air, a plate (not shown) may be connected to the base 610 at a distance so that heat may be exhausted in the lateral directions.

[67] FIGS. 5 and 6 schematically show a cooling flow path according to the present invention. As shown in the drawings, flow generated from the rear space 400 travels to the lateral spaces 500 formed on both sides of the cooking cavity 100 via the upper space 300, while part of the flow comes out of the opening 151 and turns towards the door 200. Also, another part of the flow may turn towards the lateral spaces through the opening 162 formed in the rear frame 160. The flow coming to the upper space 400 cools the heater 320 and the relay substrate 350. Desirably, the relay substrate 350 is provided to the insulating upper plate 340 along the direction of the flow, so as to minimize the hindrance to the flow. The flow passing through the lateral spaces 500 turns towards the lower space 600, and is vented through the outlet 611 (refer to FlG. 1) formed at the center of the base 610. Even though there is no particular restriction to the location of the outlet 610, it is preferably located around the center of the base 610 because a sufficient amount of heat exchange is performed as the flow travels or circulates inside the cooking apparatus as long as possible. At this time, to protect a bottom surface where the cooking apparatus is placed, a protective plate 612 may be connected to the base 610 at a distance so that the flow may be exhausted in the lateral directions. In addition, the flow passing by the lateral spaces 500 guides the flow vented through the outlet 111 of the cooking cavity 100 to the lower space 600. Meanwhile, the air flow that comes through the opening 291 of the choke cover 290 travels between the front plate 220 and the middle plate 260 being guided by the bracket 270, and is vented through the outlet 242 formed in the bottom surface of the door panel 240. As such, the input sensing unit 230 (see FlG. 1) and the control panel 250 (see FlG. 1) covered by the bracket 270 can be protected from heat and air flow, one side of the middle plate 260 blocks heat through the air flow (Although the air flow is blocked by the bracket 270, the air flow serves to block heat transfer to the input sensing unit 230 and the control panel 240.), and the other side of the middle plate 260 blocks heat through a stagnant air layer. In result, heat generated from the cooking cavity 100 is blocked and not transferred to the outside of the door 200 or the handle 210 (see HG. 1).

[68] FIGS. 7 through 9 schematically show an example of a door according to the present invention, in which the door includes a front plate 220, an input sensing unit 230, a door panel 240, a control panel 250, a middle plate 260, a bracket 270, a door frame 280, and a choke cover 290. The front plate 220 has a button type display unit 221, and the display unit 221 and the input sensing unit 230 constitute an operating panel. The door frame 280 includes a door screen 281 and a choke unit 282 to block microwaves, and hinged to the cooking cavity side through a hinge H under the door screen 281. In addition, the front plate 220, the middle plate 260, and the door screen 281 are made of transparent materials such as glass or plastic, and the door panel 240 and the choke cover 290 have openings 241 and 292, so that a user may be able to see the inside of the cooking cavity. Moreover, light-emitting sources 251 and 252 such as LEDs are provided to the front side of the control panel 250 to illuminate the display unit 221. To this end, openings 231, 232 and 242 through which light beams can pass are formed at corresponding portions in the input sensing unit 230 and the door panel 240, respectively. The choke cover 290 also has an opening 291 through which air flow for cooling the door can travel. By separately forming the choke cover 290 on the side of the opening 291 from the choke cover 290 on the side of the opening 292, assembly efficiency of the door can be improved.

[69] The middle plate 260 is mounted on the opening 241 of the door panel 240 at the opposite side of the front plate 220. The door frame 280 is mounted on the door panel 240 at a predetermined distance away from the middle plate 260 at the opposite side of the front plate 220. The choke cover 290 is mounted on the door frame 240 to cover the choke unit 282 of the door frame 280, while the door screen 281 of the door frame 280 being exposed to the opening 292 of the choke cover 290. The door panel 240 is provided with fixing projections 243 for use in fixing the control panel 250 to the rear portions on both sides thereof and a fixing projection (not shown) for use in fixing the bracket 270 to encompass the rear portion and lower side of the control panel 250, and has the middle plate 260 installed at its lower opening 241, leaving a predetermined space. The opening 241 formed in the door panel 240 is provided with a plurality of assembly hooks 244a and 245a and support units 244b and 245b that are protruded backwardly, respectively. On the upper and lower sides of the opening 241 of the door panel 240, the support unit 244b is formed between a pair of assembly hooks 244a, Meanwhile, on the both sides of the opening 241 of the door panel 240, one assembly hook 245a is provided at the upper portion and one support unit 245b is provided along the side toward the lower corner of the side. In order for the assembly hooks 244a and 245a and the support units 244b and 245b to support the front and rear surfaces of the middle plate 260, the space between the assembly hooks 244a and 245a and the support units 244b and 245b is preferred to be equal to a thickness of the middle plate 260. Moreover, the assembly hooks 244a and 245a and the support units 244a and 245b are preferred to be partially formed on the circumference of the opening 241 of the door panel 240 to minimize a flow resistance when air flow come in and out the opening 241. Furthermore, at one side (or both sides) of the rear portion of the door panel 240 is provided a wire guide unit 246 for guiding a wire connected to the control panel 250. Also, at the lower side of the door panel 240 is provided an opening 247 used for wire-connecting to the cooking cavity side, an opening 248 used for inserting/ releasing a hinge H depending on the opening/closing of the door 200 and an outlet

242 through which air having passed through the door 200 is vented. [70] As explained so far, a cooking apparatus of the present invention is capable of preventing heat generated from a cooking cavity from being transferred to the outside of a door or to a handle. [71] Also, a cooking apparatus of the present invention is capable of cooling the inside of a door using air flow and a stagnant air layer. [72] Also, a cooking apparatus of the present invention is capable of cooling the inside of a door using air flow generated from the rear space of the cooking apparatus. [73] Also, a cooking apparatus of the present invention is provided with a door that is built for enabling a user to see the inside of a cooking cavity, and is capable of blocking heat transfer to the outside of the door or to the handle. [74] Also, a cooking apparatus of the present invention is capable of preventing the heat generated from a cooking cavity from being transferred to a control panel located at a door. [75] Also, a cooking apparatus of the present invention forms a cooling flow path from a cooking cavity towards a door and is capable of preventing foreign substances from getting inside the door through the cooling air flow path. [76] Although the preferred embodiment of the present invention has been described, it will be understood by those skilled in the art that the present invention should not be limited to the described preferred embodiment, but various changes and modifications can be made within the spirit and scope of the present invention as defined by the appended claims.

Claims

[I] A cooking apparatus, comprising: a cooking cavity; and, a door opening and closing the cooking cavity and including a front plate, a door frame located at the rear of the front plate to block microwaves and a middle plate located between the front plate and the door frame to block heat transferred from the cooking cavity to the front plate. [2] The cooking apparatus as set forth in claim 1, further comprising: a flow path formed to pass by at least one of the outer surfaces of the cooking cavity; and, wherein the door is provided with an opening communicating with the flow path. [3] The cooking apparatus as set forth in claim 2, wherein the flow path is extended from the rear of the cooking cavity to the upper portion of the cooking cavity, and the opening is formed at the upper portion of the door to communicate with the flow path. [4] The cooking apparatus as set forth in claim 2, wherein the door is provided with a door flow path formed in a way that a flow coming out of the opening passes by at least one of the lateral surfaces of the middle plate. [5] The cooking apparatus as set forth in claim 4, wherein the door flow path is formed in a way that the flow coming out of the opening passes between the front plate and the middle plate. [6] The cooking apparatus as set forth in claim 4, wherein the door is provided with a bracket for guiding the flow coming out of the opening towards the at least one of the lateral surfaces of the middle plate. [7] The cooking apparatus as set forth in claim 6, wherein the bracket is located over the middle plate. [8] The cooking apparatus as set forth in claim 2, wherein the opening is provided with means for preventing foreign substances from getting inside the door. [9] A cooking apparatus, comprising: a cooking cavity; and, a door opening and closing the cooking cavity and including a door panel provided with an opening for enabling a user to see the inside of the cooking cavity; and a middle plate located on the opening of the door panel to block heat generated from the cooking cavity. [10] The cooking apparatus as set forth in claim 9, wherein the middle plate is made of a material that enables a user to see the inside of the cooking cavity.

[II] The cooking apparatus as set forth in claim 10, wherein the door is provided with a front plate mounted on the door panel to cover at least the opening and made of a material for a user to be able to see the inside of the cooking cavity through the opening of the door panel, and a door frame mounted on the door panel to block microwaves from the cooking cavity and having a part made of a material for a user to be able to see the inside of the cooking cavity through the opening of the door panel.

[12] The cooking apparatus as set forth in claim 11, wherein the door includes a choke cover located at the rear of the door frame and provided with a first opening for passing a flow into the door, and a second opening formed to allow a user to see the inside of the cooking cavity.

[13] The cooking apparatus as set forth in claim 9, wherein the door is provided with a door flow path formed to pass by at least one of the lateral surfaces of the middle plate.

[14] The cooking apparatus as set forth in claim 9, wherein the door is provided with a front plate mounted on the door panel to cover at least the opening; and a door flow path formed to pass between the front plate and the middle plate.

[15] The cooking apparatus as set forth in claim 9, wherein the door is provided with a control panel located at the upper portion of the opening of the door panel.

[16] A cooking apparatus, comprising: a cooking cavity carrying out a cooking process using microwaves; a door opening and closing the cooking cavity and provided with a door frame blocking the microwaves; a flow path extended from the cooking cavity side to the door side for a flow to pass thereon; and a choke cover formed at the door and provided with a first opening communicating with the flow path of the cooking cavity side and preventing foreign substances from getting into the door, and a second opening formed to expose the door frame.

[17] The cooking apparatus as set forth in claim 16, further comprising: a door panel mounting the door frame and provided with an opening formed for the flow to pass therethrough.

[18] The cooking apparatus as set forth in claim 17, further comprising: a middle plate located on the opening and blocking heat generated from the cooking cavity.

[19] The cooking apparatus as set forth in claim 16, wherein the choke cover is formed in a way that the choke cover of the first opening side and the choke cover of the second opening side are separately made.

[20] A cooking apparatus, comprising: a cooking cavity carrying out a cooking process using microwaves; a door opening and closing the cooking cavity and provided with a door frame to block the microwaves; a flow path extended from the cooking cavity side to the door side for a flow to pass thereon; a door panel mounting the door frame and provided with an opening formed for the flow to pass therethrough; a middle plate located on the opening and blocking heat generated from the cooking cavity; and, a choke cover formed at the door and provided with a first opening communicating with the flow path of the cooking cavity side, and a second opening formed to expose the door frame; wherein the middle plate, the door frame, and the choke cover are mounted on the door panel for the flow to form a flow path of the door side passing from the first opening of the choke cover, via the upper portion of the door frame, through at least one of the lateral surfaces of the middle plate.