COOKING APPLIANCE

A cooking appliance including a heater that is movable vertically in a cooking chamber is proposed. The cooking appliance includes a casing having a cooking chamber therein, a door rotatably provided at one portion of the casing and opening and closing the cooking chamber, a moving assembly installed to move vertically and provided with a heater; and a food detection system that detects whether the moving assembly is in contact with food inside the cooking chamber. With the cooking appliance, there is an advantage in that cooking efficiency is improved and malfunction or damage to parts is prevented.

TECHNICAL FIELD

The present disclosure relates generally to a cooking appliance including a heater vertically movable in a cooking chamber.

BACKGROUND ART

A cooking appliance is provided to cook food accommodated therein by using heat of a heater provided as a heating source.

Generally, the cooking appliance includes a main body including a cooking chamber that is a space accommodating food therein, at least one heater provided in the main body, and a door rotatably coupled to the main body and closing and opening a front surface of the cooking chamber.

Recently, in order to increase the effectiveness of the cooking appliance, a steam generator as in Korean Patent Application Publication No. 10-2018-0126237 may be added to the cooking appliance.

Furthermore, in the food thawing device disclosed in U.S. Pat. No. 4,303,820, a pair of flat electrodes defining a food thawing zone is provided, and one of the pair of flat electrodes is provided to be movable for insertion of a frozen food rod. In addition, a relatively low wattage power supply device provides even energy distribution across the food load for smooth heating (thawing).

In the apparatus and method for reheating a package of refrigerated or frozen food disclosed in U.S. Pat. No. 8,258,440, the apparatus and method for reheating a package of refrigerated or frozen food are disclosed. In addition, the heating mechanism is in conductive heat transfer contact with the food package, and heats food to a reheat temperature, and is operated for a reheat time for reheating the food package, and then is maintained at the reheat temperature if desired.

However, a link-type elevating system has been disclosed in the conventional cooking appliance, but due to the structure such as the heater descending by its own weight for thawing food, ascending and descending of the heater are not precisely performed, and a crash prevention with respect to food in the cooking appliance or original position control of the heater is insufficient. Therefore, there is a risk of leakage of electromagnetic waves in the cooking appliance and occurrence of safety accidents and failure due to product damage

SUMMARY OF THE DISCLOSURE

Technical Problem

Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to provide a cooking appliance with a heater moving vertically intentionally in the cooking chamber.

Furthermore, another objective of the present disclosure is to provide a cooking appliance configured to efficiently shield electromagnetic waves through perimeter of a heater system that is raised and lowered.

Another objective of the present disclosure is to provide a cooking appliance capable of accurately detecting an original position of a heater that is raised and lowered in a cooking chamber.

Another object of the present disclosure is to provide a cooking apparatus that stops a moving assembly or a heater descending inside of a cooking chamber when it collides with food.

Problem Solving

In order to achieve the above objectives, according to the present disclosure, a cooking appliance according to the present disclosure includes a heater moving vertically inside a cooking chamber. Therefore, cooking is possible with the heater moving closer to food.

In the present disclosure, a detection function is provided for detecting whether a moving assembly or a heater interferes with food inside a cooking chamber. That is, the function is to detect whether the moving assembly or the heater is coming into contact with food, containers (plates, etc.) placed on the floor, or shelves when descending inside the cooking chamber.

In the present disclosure, when the heater or the moving assembly moving vertically inside the cooking chamber interferes with food or the like, the movement of the heater or the moving assembly is stopped. That is, when the moving assembly comes into contact with an object inside the cooking chamber, the moving assembly is stopped. The object inside the cooking chamber may be an object such as a container (plate) or shelf as well as a food.

In the present disclosure, a flexible coupling is used for power transmission for vertical movement of a heater.

In the present disclosure, the cooking appliance may include: a casing in which the cooking chamber is provided; a door rotatably provided at one portion of the casing and opening and closing the cooking chamber; a moving assembly provided to be vertically movable inside the cooking chamber and including the heater; and a food detection system provided at one portion of the casing and detecting whether the moving assembly interferes with food inside the cooking chamber.

The food detection system may include a moving control means restraining the moving assembly to move vertically and a protection switch switched on/off by the moving control means.

The moving control means comprises: a motor generating rotation power; a lead screw provided at one portion of the motor and rotated in conjunction with rotation generated by the motor; a lead nut fastened to the lead screw by screwing; and a connection coupling for connecting one end of the lead screw to a motor shaft.

The connection coupling may be a flexible coupling.

The protection switch may be installed to be spaced apart from one end of the lead screw by a predetermined distance.

A protection lever is provided between the protection switch and the lead screw to selectively press a protection button of the protection switch by being restrained by the lead screw.

A distance between one end of the lead screw and the protection switch or the protection lever may be smaller than an extendable length of the connection coupling.

The protection lever is formed to be elastic due to its own material or shape.

The protection lever may have a shape that is bent more than once.

The moving assembly may be stopped when the protection button of the protection switch is pressed and turned on.

The moving assembly stops descending and rises again when the protection button of the protection switch is pressed and turned on.

The moving assembly stops descending when the protection button of the protection switch is pressed and turned on, and then rises after a predetermined time.

When the protection button of the protection switch is pressed and turned on, a message or a signal is displayed or transmitted to the outside to inform the food contact.

When the moving assembly interferes with the food inside the cooking chamber, the lead nut stops moving even if the lead screw rotates.

Advantageous Effect

The cooking appliance according to the present disclosure has the following effects.

First, the cooking appliance according to the present disclosure is configured to allow the heater to move vertically inside the cooking chamber. Therefore, food is cooked with the heater moving closer to the food in the cooking chamber, so that it is possible to minimize heat loss and reduce a cooking time of food.

Second, in the present disclosure, the flexible connection coupling is provided between the motor and the lead screw. Therefore, it is possible to reduce power loss due to a concentricity error between the motor shaft and the lead screw and to facilitate transmission of rotation power.

Third, in the present disclosure, the guide members are provided to guide the vertical movement of the moving assembly. In other words, the plurality of roller-type guide members is provided to control the vertical movement of the moving assembly. Therefore, when the moving assembly with the heater moves vertically, it is possible to prevent interference of the heater housing, the protection cover, and the fixed frame and prevent damage to parts thereof and occurrence of noise.

Fourth, in the present disclosure, the insulating member is provided in the moving assembly and shields the gap between the moving assembly and the casing of the cooking appliance. Therefore, it is possible to prevent the leakage of electromagnetic waves through the gap between the moving assembly and the casing.

Fifth, in the present disclosure, the edge of the insulating member provided in the moving assembly is overlapped with the upper plate providing the upper surface of the cooking chamber. Therefore, when the moving assembly is raised and located at the original position thereof in the cooking chamber, it is possible to prevent the leakage of electromagnetic waves in the cooking chamber to the outside space.

Sixth, in the present disclosure, the food detection system is provided to detect whether or not the moving assembly interferes with the food when the moving assembly is descending. Therefore, when the food and the moving assembly come into contact with each other, the moving assembly stops descending, so that it is possible to prevent damage to the food and the parts thereof.

Seventh, in the present disclosure, the original position detection means is provided to detect whether or not the moving assembly or the heater is located at the upper end of the cooking chamber, which is the original position thereof. Therefore, since the original position of the heater is accurately detected, collision or damage of the part (moving assembly) due to the over-rotation of the motor is prevented.

Eighth, in the present disclosure, microwave is operated only when the moving assembly moving vertically in the cooking chamber is returned to the upper end of the cooking chamber. Therefore, the electromagnetic wave leakage through the gap between the moving assembly and the upper surface of the cooking chamber is shielded.

Ninth, in the present disclosure, a resonance chamber is provided for applying an electromagnetic wave to a shielding means or for offsetting the electromagnetic wave. That is, the resonance chamber for applying an electromagnetic wave to the insulating member or the protection cover or offsetting the electromagnetic wave is provided. Therefore, electromagnetic waves leaking to the outside may be effectively shielded.

Tenth, in the present disclosure, the flexible coupling is used as the connection coupling for transmitting power of the motor, and an interval between the lead screw and the protection lever for turning on the protection switch is installed to have a size smaller than that of the connection coupling. Therefore, even when the moving assembly is lowered, the connection coupling may be prevented from being damaged even when the moving assembly is in contact with food.

DETAILED DESCRIPTION OF THE DISCLOSURE

Hereinafter, a cooking appliance according to the present disclosure will be described in detail with reference to accompanying drawings. The cooking appliance according to the present disclosure may be food cookers of various shapes such as a microwave, an electric oven, etc.

FIG.1is a perspective view showing the cooking appliance according to an embodiment of the present disclosure. In other words, inFIG.1, to describe the cooking appliance according to the present disclosure, a main structure inside the cooking appliance with removing an outer cover will be shown as the perspective view.

As shown in the drawing, the cooking appliance according to the present disclosure includes a casing10in which a cooking chamber12is provided, and a door20provided at one portion of the casing10and opening and closing the cooking chamber12.

The casing10serves as a main body of the cooking appliance, and may be shaped in a rectangular box as shown in the drawing, and be preferably open at a front portion thereof so as to put in and take out food.

As described above, when the front portion of the casing10is open, the door20is provided for shielding the cooking chamber when cooking food, and the door20may be rotatably provided on a hinge so as to be able to open and close.

In the present disclosure, as shown in the drawing, the case in which the door20is rotatably provided on the hinge at a lower end is illustrated.

A front frame14is provided at a front surface of the casing10and provides the appearance of the front portion of the casing10, and various display parts (not shown) or deco panels may be provided thereto.

A support plate30may be provided in the cooking chamber12to support food or a container, and the support plate30may be rotatably provided.

A movable heater system100may be provided above the casing10as shown in the drawing. The movable heater system100is a system allowing a heater to move vertically in the cooking chamber12.

The heater may be provided above the casing10and emit heat, and at least two heaters may be provided. In other words, the movable heater system100may include the heater and the heater may move vertically in the cooking chamber12, and the heater may be additionally provided in the casing10in addition to the movable heater system100.

In addition, the cooking appliance according to the present disclosure may include a function of detecting whether or not the heater of the movable heater system100comes into contact with food in the cooking chamber12or is spaced apart from the food at a predetermined distance and a function of detecting recovery of the heater of the movable heater system100to the original location thereof.

The movable heater system100as described above and various functions thereof will be described below.

FIGS.2to14are views showing the structure of the movable heater system100. In other words,FIGS.2and3are a perspective view and an exploded-perspective view showing the structure of the movable heater system100.FIGS.4to7are a plane view, a front view, a side view, and a front sectional view of the movable heater system100. Furthermore,FIG.8is a perspective view showing the structure of the movable heater system100with the inner heater lowered.FIGS.9to11are a plane view, a front view, and a side view showing the movable heater system100shown inFIG.8.FIGS.12to14are exploded-perspective views showing a fixed assembly, a moving assembly, and a link assembly that constitute the movable heater system100.

As shown in the drawings, the movable heater system100includes a heater210emitting heat, and the heater210may be provided to be vertically movable in the cooking chamber12.

Furthermore, the casing10or the movable heater system100may have a function of detecting whether the heater210comes into contact with food inside the cooking chamber12or is spaced apart from the food at a predetermined distance and a function of detecting recovery of the heater210to the original position of the heater.

Here, the object, such as a contact detection or a detection of a certain distance separation is exemplified as food, but it may also be applied to contact with a container (a plate or the like) placed on a floor or shelf inside the cooking chamber, in addition to food.

The movable heater system100may include a moving assembly200to which the heater210is mounted and protected, a fixed assembly300provided at one portion of the casing10and controlling a vertical movement of the moving assembly200, and a link assembly400provided at one portion of the moving assembly200and movably connecting the moving assembly200to the fixed assembly300.

The moving assembly200is separably provided from the casing10to be movable inside the cooking chamber12, and surrounds at least side portion of the heater210so that it is preferable that heat of the heater210is concentrated downward and is prevented from emitting sideways.

The fixed assembly300is securely provided above the casing10and supports the moving assembly200so that the moving assembly200moves in a vertical direction while being supported by an upper surface of the casing10.

Therefore, the fixed assembly300includes a moving control means500, and the moving control means500restrains the moving assembly200so that the moving assembly200vertically moves by control of the link assembly400.

The link assembly400may be provided above, etc. the moving assembly200, and includes at least one link, thereby guiding the moving assembly200so that the moving assembly200moves vertically while being connected to the fixed assembly300.

Upper and lower ends of the link assembly400may be rotatably connected to the fixed assembly300and the moving assembly200, respectively.

The fixed assembly300may include an upper plate310providing an upper surface of the cooking chamber12, a protection cover320provided at the upper plate310and blocking electromagnetic waves via a gap between the moving assembly200and the fixed assembly300, and a fixed frame330provided above the upper plate310and supporting the moving control means500.

The upper plate310is shaped in a rectangular plate having a predetermined thickness and provides the upper surface of the cooking chamber12. In addition, a center portion of the upper plate310is vertically perforated and provides a path through which the moving assembly200moves vertically.

The fixed frame330may be provided to be spaced apart from the protection cover320.

More specifically, the protection cover320may also have a rectangular shape like the upper plate310, and a hole vertically perforated may be formed in a center portion of the protection cover320like the upper plate310and may have a rectangular frame shape. Therefore, the moving assembly200may move vertically via the center holes of the upper plate310and the protection cover320.

Then, the fixed frame330may have a rectangular shape smaller than the hole formed in the center portion of the protection cover320. Therefore, a predetermined gap is formed between the fixed frame330and the protection cover320, and it is preferable that a heater housing220of the moving assembly200is accommodated in the gap and moves vertically.

The fixed frame330may be securely provided above the upper plate310, and therefore, a fixed guide340may be provided between the upper plate310and the fixed frame330.

As shown in the drawing, the fixed guide340may have a shape of ‘∩’ (when which is seen from the front side). Therefore, an upper end of the fixed guide340may be coupled to the fixed frame330, and a lower end thereof may be fixed to the upper plate310or the protection cover320.

Specifically, the fixed guide340may include a frame coupling part342coupled to the fixed frame330, and an upper coupling part344fixed to the upper plate310or the protection cover320. In the present disclosure, the case in which the upper coupling part344, i.e., the lower end of the fixed guide340is fastened to the upper surface of the upper plate310is illustrated.

A plurality of fixed guides340may be provided and, in the present disclosure, the case in which two fixed guides340are provided at an upper portion of the upper plate310to be spaced apart from each other forward and rearward at a predetermined gap and supports the fixed frame330is illustrated.

The fixed assembly300may include a sliding rail350slidingly supporting a moving bracket560, a lead nut530, or the like, and the moving bracket560and the lead nut530will be described below.

Specifically, the sliding rail350is provided at an upper surface of the fixed frame330to have a predetermined transversal length, and the moving bracket560or the lead nut530, which will be described below, may be provided on the sliding rail350to be movable left and right.

The moving control means500may be provided above the fixed frame330.

The moving control means500may include a motor510generating rotating power, a lead screw520provided at one portion of the motor510and rotated in conjunction with rotation generated by the motor510, the lead nut530fastened to the lead screw520by screwing, and a connection coupling540for connecting one end of the lead screw520to a motor shaft.

The motor510may generate rotation power, and a stepping motor may be used as the motor510so as to perform precise rotation control. The stepping motor may perform the supply of forward and reverse rotation movements in response to a rotation angle by pulse control.

For example, a stepping motor used as the motor510may be used to have a speed of 154.2 RPM (revolutions per minute) and a pulse input may be 154.2×200 pulses per minute (1 pulse=1.8° rotation, 1 rotation=200 pulses).

As shown in the drawings, the lead screw520may be a fine cylinder of a predetermined length, of which an outer surface is formed in a male screw and, herein, the lead screw520may be fastened with the lead nut530having a female screw corresponding to the male screw of the lead screw520. Therefore, when the lead screw520is rotated by the power of the motor510, the lead nut530moves left and right along the lead screw520. As described above, the lead screw520and the lead nut530serves to change the forward/reverse rotation movements into a linear movement.

A connection coupling540may be provided between the motor510and the lead screw520, and the connection coupling430may connect one end of the lead screw520to the motor shaft. As shown in the drawings, the connection coupling540may be provided at a right end of the lead screw520and the motor shaft protruding leftward from the motor510.

The connection coupling540is used to reduce power loss due to a concentricity error between the shaft of the motor510and the shaft of the lead screw520and to make rotation smooth, and it is preferable that flexible coupling is used as the connection coupling. In other words, as the connection coupling540, MST-type or MSTS-type flexible coupling may be used.

The motor510may be provided at a fixed bracket550securely mounted to the fixed assembly300, and the lead nut530may be mounted to the moving bracket560movably installed to the fixed assembly300.

Specifically, the fixed frame330may be provided above the upper plate310to be spaced apart therefrom by the fixed guides340. A predetermined gap may be provided between the fixed frame330and the protection cover320, thereby providing a moving path of the heater housing220.

Furthermore, both of the fixed bracket550and the moving bracket560are provided above the fixed frame330of the fixed assembly300. As shown in the drawings, the fixed bracket550is securely mounted to the upper surface of the fixed frame330, and the moving bracket560is movably provided to move closer to or away from the fixed bracket550above the fixed frame330.

As described above, the sliding rail350is securely installed to the fixed frame330, and a sliding member352may be slidingly provided at the sliding rail350and support the moving bracket560.

As shown in the drawings, the sliding member352having a rectangular plate shape is provided at an upper portion of the sliding rail350to be slidable left and right, and the moving bracket560is fixed on an upper surface of the sliding member352and is movable left and right.

The motor510is mounted to the fixed bracket550and the lead nut530is mounted to the moving bracket560. Therefore, when the lead screw520is rotated in response to rotation of the motor510mounted to the fixed bracket550, the lead nut530moves left and right, and eventually, the moving bracket560moves left and right along the sliding rail350.

Link upper ends of the link assembly400is rotatably installed to the fixed bracket550and the moving bracket560. In other words, when the left and right upper ends of the ‘X’-shaped link provided in the link assembly400are respectively connected to the fixed bracket550and the moving bracket560, left and right movement of the moving bracket560allows the left and right upper ends of the ‘X’-shaped link to move closer to or away from each other, so that the moving assembly200fixed to a lower end of the link assembly400moves up and down.

A protection bracket360and a position bracket380may be provided on the fixed frame330of the fixed assembly300.

As shown in the drawings, the protection bracket360may be provided on an upper surface of a left end of the fixed frame330, and a protection switch370may be installed thereto, and the protection switch370has a detection function for protecting the parts from interference (contact) of the heater210and food.

The protection switch370may include a microswitch and may be installed to be turned on/off by the moving control means500.

The protection switch370constitutes a food detection system375to be described below with the moving control means500.

The protection switch370may be spaced apart from one end of the lead screw520by a predetermined distance. That is, as illustrated, the left end of the lead screw520and the protection switch370may be installed to be spaced apart from each other by a predetermined distance.

The protection bracket360may further include a protection lever372. That is, as illustrated, the protection lever372may be provided between the protection switch370and the lead screw520. The protection lever372is forced by the lead screw520to selectively press a protection button370aof the protection switch370.

Therefore, when the left end of the lead screw520moves to the left and pushes the protection lever372to the left, the protection lever372presses the protection button370aof the protection switch370to be turned on.

As shown in the drawings, the position bracket380may be provided at an upper surface of a right end of the fixed frame330, and a the position switch390, etc. may be installed thereto, and the position switch390allows the moving assembly200to be recovered to the original location thereof or detects that the moving assembly200is located at the original location.

The protection cover320includes a plurality of guide members322guiding vertical movement of the moving assembly200. As shown in the drawings, four guide members322may be respectively provided at four corners of the protection cover320of the rectangular frame shape, and the guide members322serve to support the heater housing220to prevent the heater housing220from interfering with the protection cover320when the heater housing220to be described below passes through the gap between the fixed frame330and the protection cover320.

The moving assembly200may include the heater housing220and an insulating member230, the heater housing220covering and protecting the heater210and the insulating member230being provided at one end of the heater housing220and blocking heat or electromagnetic waves.

The heater housing220may have a rectangular box shape as shown in the drawings, and a bottom surface thereof may have at least one hole, which is formed by being vertically perforated, so as to allow the passage of heat of the heater210.

The heater housing220may move up and down by passing through the gap between the fixed frame330and the protection cover320. Therefore, the heater housing220has the rectangular box shape with an open upper portion, and has a predetermined thickness. Thicknesses of the four lateral surfaces of the heater housing220are preferably formed smaller than the size of the gap between the fixed frame330and the protection cover320.

The heater housing220may have guide grooves222selectively storing the fixed guide340. In other words, as shown in the drawings, the guide grooves222are formed in the left and right lateral surfaces of the heater housing220by being depressed downward from upper ends of the surfaces at a predetermined length. The frame coupling part342of the fixed guide340is stored in the guide grooves222when the moving assembly200is raised.

The insulating member230is preferably formed to have a rectangular frame shape as shown in the drawings, and lateral ends thereof are preferably formed to protrude outward than lateral ends of the heater housing220. The exterior size of the insulating member230is formed larger than the lateral size of the heater housing220, so that the insulating member230may serve to shield electromagnetic waves from leaking through the gap between the fixed frame330and the protection cover320when the moving assembly200is raised.

A seating groove232may be formed on an upper surface of the insulating member230by being depressed downward and on which a lower end of the heater housing220is seated.

The heater210is stored and fixed inside the heater housing220.

The heater210may have a left-right or front-rear long shape and a plurality of heaters may be preferably provided in an inner lower end of the heater housing220.

Heater brackets212are provided at opposite ends of each heater210and guide mounting of each heater210or power supply of each heater210.

A pair of support ends240having a symmetrical shape may be provided at left and right portions of a lower inner end of the heater housing220, and the support ends240may support the plurality of heaters210.

Meanwhile, the support ends240may support the lower end of the link assembly400. In other words, upper ends of the support ends240may be coupled to the lower end of the link assembly400. Therefore, the moving assembly200may move up and down while being fixed to the lower end of the link assembly400.

A heater cover250may be provided above the heaters210to cover upper portions of the heaters210, and the heater cover250may have the shape corresponding to the number or the shape of the heaters210.

The link assembly400has a structure including at least one link, and preferably, the upper end thereof is rotatably connected to the fixed assembly300and the lower end thereof is rotatably connected to the moving assembly200.

The link assembly400may include a pair of front links410and420and a pair of the rear links430and440that are spaced apart from each other forward and rearward at a predetermined distance, and a link frame450may be provided at lower ends of the front links410and420and the rear links430and440, the link frame340being coupled to the moving assembly200.

In addition, at least one of left and right ends of each of the front links410and420and the rear links430and440may be preferably installed to movable while being coupled to the link frame450.

Specifically, the pair of front links410and420may be configured such that a front first link410and a front second link420formed in a ‘X’-shape may be coupled to cross each other to be rotatable on the center, and the pair of rear links430and440may be configured such that a rear first link430and a rear second link440formed in a ‘X’-shape may be coupled to cross each other to be rotatable on the center.

The lower ends of the front first link410and the rear first link430, which are installed to be spaced apart from each other forward and rearward by the predetermined distance, may be connected to each other by a connection link460, and the lower ends of the front second link420and the rear second link440may be connected to each other by the connection link460.

At least one of the left and right lower ends of the front links410and420and at least one of the left and right lower ends of the rear links430and440may be movably installed while being coupled to the link frame450. According to the present disclosure, as shown in the drawings, the case in which the lower ends of the front first link410and the rear first link430are installed to be movable left and right of the link frame450is illustrated.

Therefore, first link protrusion holes452may be preferably formed at a left half portion of the link frame450, and the first link protrusion hole452may accommodate lower end shafts of the front first link410and the rear first link430and guide transverse movement thereof.

The link frame450may include a position member470, etc., and the position member470may detect the recovery of the moving assembly200to the original position thereof. The position member470may be formed to protrude upward from an upper surface of the link frame450by a predetermined height, and an upper end of the position member470may selectively interfere with the position switch390.

An original position detection means and a contact detection means may be provided at one portion of the fixed assembly300, and the original position detection means detects the original position of the moving assembly200and the contact detection means detects whether or not a lower end of the moving assembly200touches the food inside the cooking chamber12.

The original position detection means detects whether or not upward movement of the moving assembly200in the cooking chamber12is completed, and may include the position switch390, etc.

The contact detection means detects whether or not the lower end of the moving assembly200with the heaters210touches the food, and may include the protection switch370, etc.

FIGS.15to25are views showing an example of each part constituting the movable heater system100in detail.

First,FIG.15is an exploded-perspective view showing the upper plate310, the protection cover320, and the fixed frame330that constitute the fixed assembly300.

As shown in the drawing, the upper plate310has a rectangular plate shape, and an upper hole312of a rectangular hole with a predetermined size is formed by being vertically perforated therein. The upper hole312serves as a path through which the moving assembly200reciprocates up and down. Therefore, the inner size of the upper hole312is preferably formed larger than the outer size of the heater housing220.

The upper plate310may include a plurality of choke pieces314. In other words, as shown in the drawing, the plurality of choke pieces314may extend upward on an inner circumferential surface of the upper plate310having the rectangular frame shape, the plurality of choke pieces being perpendicularly bent upward.

Specifically, the plurality of upward protruding choke pieces314may be formed on edges of the upper hole312formed at the center portion of the upper plate310, and the plurality of choke pieces314serves to block leakage of electromagnetic waves inside the cooking chamber12.

Between the plurality of choke pieces314, a gap hole314ahaving a “U” shape (when viewed from the side or the front and rear) is formed. That is, the plurality of choke pieces314are installed at equal intervals, and between the plurality of choke pieces314, the gap hole314ais formed with a predetermined size to function as an electromagnetic wave extinction.

A choke groove314bmay be further formed in the choke piece314. As illustrated, the choke groove314bhas a shape recessed from a side surface of the choke piece314to one side. That is, as shown, the choke groove314brecessed to a predetermined depth is formed outside the central portion of the choke piece314.

The choke groove314b, together with the gap hole314a, may prevent electromagnetic waves inside the cooking chamber12from leaking to the outside. Specifically, when microwave is used in the cooking chamber12, the electromagnetic waves generated in the cooking chamber12may leak to the outside through a gap between the upper plate310and the moving assembly200. In this case, an electromagnetic wave that leaks to the outside through the gap between the upper plate310and the moving assembly200passes through the gap hole314aor passes through the choke groove314b, so that the wavelength of the electromagnetic wave is dispersed and extinct.

Preferably, the protection cover320may have a rectangular frame shape corresponding to the upper plate310, and the size of an exterior edge may be preferably formed in size smaller than an exterior edge of the upper plate310.

As shown in the drawing, a protection hole325may be formed in the center portion of the protection cover320by being vertically perforated, the protection hole312corresponding to the upper hole312, thereby allowing the vertical movement of the heater housing220.

As shown in the drawing, preferably, the protection cover320may be formed to be stepped so that the height of an inner edge is higher than the height of an outer edge.

Specifically, the protection cover320may include a protection stepped part324, a protection lower end part326, and a protection upper end part328. The protection stepped part324may be formed to have sections of ‘┌’ and ‘┐’ shapes (when the protection stepped part is seen from the left and right or the front and rear), the protection lower end part326may extend to be perpendicularly bent sideways from a lower end of the protection stepped part324, and the protection upper end part328may extend to be perpendicularly bent to the upper side from an inner edge of the protection stepped part324.

The choke pieces314of the upper plate310may be accommodated under the protection stepped part324.

As shown in the drawing, the fixed frame330may be formed to have a section of ‘∩’-shape (the fixed frame is seen from the side). Therefore, the fixed frame330may include a horizontal end332of a flat plate shape having a predetermined thickness, and vertical ends334extending by being perpendicularly bent downward from front and rear ends of the horizontal end332.

A pair of link passing holes336may be formed in the horizontal end332by being vertically perforated. Preferably, the pair of link passing holes336may be formed to have predetermined transverse lengths, and here, the link assembly400may serve as a passage through which the link passes. In other words, the link passing holes336may be installed such that the front links410and420and the rear links430and440pass through vertically or allow the front links410and420and the rear links430and440to pass therethrough.

FIG.16is a perspective view showing the structure of the guide members322.

As shown in the drawing, the guide members322may include a roller322a, a roller shaft332b, a roller support part322c, and a roller fixation end322d. The roller322amay be selectively brought into contact with the outer surface of the heater housing220, the roller shaft332bmay be a rotary center of the roller322a, the roller support part322cmay rotatably support the roller322aor the roller shaft332b, and the roller fixation end322dmay extend to be perpendicularly bent from a lower end of the roller support part322cand tightly fixed to the protection cover320.

The roller322amay be shaped in a cylindrical shape or a canister shape, and a material thereof may be an elastic material such as rubber. In addition, the roller322amay be rotatably connected to the roller shaft332b, or the roller322aand the roller shaft332bmay be fixed to each other. When the roller322aand the roller shaft332bare fixed to each other or provided to be integrated with each other, the roller shaft332bshould be connected to an upper end of the roller support part322c.

The roller support part322cmay be shaped in a flat plate having a predetermined thickness as shown in the drawing, or may have a bent shape.

The roller fixation end322dis provided by extending from the roller support part322c, and the roller fixation end322dmay be bent so as to be perpendicular to the roller support part322cor inclined at a predetermined angle against the roller support part322c.

The roller fixation end322dmay be preferably securely mounted to an upper surface of the protection stepped part324of the protection cover320. Therefore, an end (inner end) of the roller322ama protrudes partially into the inside space of the protection hole325of the protection cover320, thereby being brought into contact with the outer surface of the heater housing220passing through the gap between the protection cover320and the fixed frame330.

FIGS.17and18are an exploded-perspective view and a front view showing the moving control means500.

As shown in the drawing, the lead screw520of the moving control means500may have the transversally long shape, and a screw thread may be preferably formed in the outer circumferential surface thereof. In addition, an insertion protrusion522may protrude rightward from a right end of the lead screw520, and the insertion protrusion522may be fitted into a center groove of the connection coupling540.

The lead nut530may have a nut part532, a nut fixation part534, etc., and the nut part532may have a canister shape so that the lead screw520passes therethrough, and the nut fixation part534may extending perpendicularly to the nut part532and fix the nut part532to the moving bracket560.

A female screw may be formed on an inner circumferential surface of the nut part532of the lead nut530, the female screw corresponding to the male screw formed on the outer circumferential surface of the lead screw520and, preferably, the lead screw520and the lead nut530may be coupled to each other by screwing.

As described above, the connection coupling540may be configured of flexible coupling, and may have a predetermined transverse elasticity or a predetermined amount of transverse length change thereof (reduction and tension of length) may be performed.

The use of the connection coupling540reduces power loss due to a concentricity error between the motor510and the lead screw520and transmits rotation smoothly.

The motor510generates the rotation power as described above and supplies the rotation power to the lead screw520. Preferably, the motor shaft (not shown) of the motor510may be inserted into and fixed to the center groove of the right end of the connection coupling540.

FIG.19is a perspective view showing the structure of the fixed bracket550. As shown in the drawing, the fixed bracket550may include a motor seating end552, a motor fixation end554, and a link fastening end556, and the motor seating end552may be formed to have a flat surface in an upper surface thereof to support the motor510, so that the motor510is securely seated thereon, the motor fixation end554may extend from the motor seating end552to be perpendicular to the upper side and support a lateral surface of the motor510, and the link fastening end556may extend upward from each of front and rear ends of the motor seating end552and rotatably support the upper ends of the front links410and420and the rear links430and440.

Fixing fastening ends558may be formed on each of left and right ends of on the motor seating end552, and the fixing fastening ends558may allow the fixed bracket550to be securely mounted to the upper surface of the fixed frame330by fastening tools such as a bolt, etc. As shown in the drawing, the fixing fastening ends558may be formed to have the position lower than the height of the motor seating end552.

As shown in the drawing, the motor fixation end554may be formed into a vertical surface, and a motor hole554amay be formed in the motor fixation end554by being perforated transversally. The motor hole554amay have a diameter of a predetermined size, and the motor shaft (not shown) of the motor510or the connection coupling540may be accommodated in the motor hole554ato passes through transversally.

A pair of link fastening ends556may have right upper link shafts557, and the right upper link shafts557may protrude forward and rearward from the pair of link fastening ends557to support the upper ends of the front first link410and the rear first link430so that the upper ends of the front first link410and the rear first link430may be rotatably connected to the right upper link shafts557.

In addition, a reinforcement part556amay be formed on a front or rear surface of the pair of link fastening ends556by protruding forward or rearward and may serve to reinforce the rigidity.

FIG.20is a perspective view showing a structure of the moving bracket560. As shown in the drawing, the moving bracket560may have a square or rectangular section at a lower surface thereof and, preferably, the moving bracket560may be closely fixed to the upper surface of the sliding member352.

As shown in the drawing, a nut support end562may protrude rightward from a right surface of the moving bracket560. The nut support end562may support the lead nut530so that the lead nut530may be seated and fixed thereon, and as shown in the drawing, the nut support end562may have at least a shape corresponding to a shape of a lower end of the lead nut530so as to support the lower portion of the lead nut530.

A screw groove564may be formed at the center portion of the moving bracket560, the screw groove564being depressed downward while passing through transversally. Preferably, the screw groove564may be formed larger than an outer diameter of the lead screw520, and the lead screw520may be accommodated therein.

Left upper link shafts566may protrude forward and rearward on a front surface and a rear surface of the moving bracket560. The left upper link shafts566may be a portion where the link upper end of the link assembly400may be rotatably connected thereto together with the right upper link shafts557. In other words, it may be preferable that the upper ends of the front second link420and the rear second link440is rotatably connected to the pair of left upper link shafts566, respectively.

Furthermore, a reinforcement part566amay protrude forward and rearward from the front surface and the rear surface of the moving bracket560together with the reinforcement part556aformed on the link fastening end556.

FIG.21is a front perspective view showing a structure of the protection bracket360.

As shown in the drawing, the protection bracket360may include a protection support part362and a protection fixation end364, and the protection support part362may have predetermined vertical size and thickness, and the protection fixation end364may be perpendicularly bent from a lower end of the protection support part362and closely fixed to the upper surface of the fixed frame330.

Furthermore, the protection switch370may be installed at the protection support part362to interfere with the lead screw520and detect whether or not the moving assembly200is brought into contact with the food. To this end, a protection installation end366may be provided at the protection support part362to support the protection switch370.

In the embodiment, as shown in the drawing, the case in which the protection installation end366extends rearward from a rear surface of the protection support part362to support the protection switch370is illustrated.

FIG.22is a front perspective view showing a structure of the position bracket380.

As shown in the drawing, the position bracket380may include a position support part382and a position fixation end384, and the position support part382may have a predetermined vertical size and thickness, and the position fixation end384may be perpendicularly bent from a lower end of the position support part382and closely fixed to the upper surface of the fixed frame330.

Furthermore, the position support part382may include the position switch390, etc., and the position switch may interference with the position member470and detect whether or not the moving assembly200is recovered to the original position thereof. To this end, a position installation end386may be provided at the position support part382to support the position switch390.

In the embodiment, as shown in the drawing, the case in which the position installation end386extends rearward from the rear surface of the protection support part362and supports the position switch390, etc. is illustrated.

Meanwhile, the position bracket380may be coupled to the fixed bracket550and, to this end, a bracket coupling end388may be formed at a left end of the position bracket380to be perpendicular to the position support part382.

FIG.23is an exploded-perspective view showing a structure of the heater housing220and the insulating member230.

As shown in the drawing, the heater housing220may have a rectangular box shape with an open upper portion, and a heater net224may be formed at a bottom surface of the heater housing220.

As shown in the drawing, the heater net224may preferably have a net shape with a plurality of vertical through holes. The structure described above is for efficiently transmitting the radiant heat of the heater210provided in the heater housing220to the lower space through the bottom surface of the heater housing220.

As shown in the drawing, the insulating member230may have an insulation hole234vertically perforated therein so as to have a rectangular frame shape, and when the moving assembly200is recovered to an upper end of the cooking chamber12as the original position, the insulating member230shields the gap between the protection cover320and the fixed frame330to prevent outward leakage of electromagnetic waves, etc.

A size of the insulating member230may be preferably formed larger than an inner diameter of the upper hole312and the protection hole325. In other words, a left-right and front-rear exterior size of the rectangular insulating member230may be formed larger than a front-rear and left-right size of the inner diameter of each of the upper hole312and the protection hole325, and when the moving assembly200is recovered to the original position at the upper end of the cooking chamber12, it is preferable that the insulating member230and the upper plate310are partially overlapped with each other so that the electromagnetic waves in the cooking chamber12are prevented from leaking outward.

FIG.24is a perspective view showing a structure of the support ends240of the moving assembly200.

As shown in the drawing, the pair of support ends240may be installed to be transversally symmetrical to each other, and it is preferable that the pair of support ends240supports the plurality of heaters210and allows the moving assembly200to be coupled to the lower end of the link assembly400.

Therefore, each of the support ends240may include a bottom support part242, a heater seating part244, and a link connection part246, and the bottom support part242may be closely fixed to an upper surface of the bottom surface of the heater housing220, the heater seating part244may protrude upward from one end of the bottom support part242and support the heater210, and the link connection part246may extend by being perpendicularly bent from another end of the bottom support part242upward.

The link connection part246may be formed in size larger than a vertical height of the heater seating part244as shown in the drawing, and a lower end of the link frame450of the link assembly400may be closely fixed on an upper end of the link connection part246.

The heater seating part244may have grooves depressed downward to allow the heaters210to pass through the grooves or to support the heaters210, and the heater brackets212may be fixed to the grooves.

FIG.25is an exploded-perspective view showing a main structure of the link assembly400.

As shown in the drawings, the front first link410and the front second link420may rotatably cross to each other into a ‘X’-shape on the center portions thereof, and the rear first link430and the rear second link440may rotatably cross to each other into a ‘X’-shape on the center portions thereof.

Therefore, a link center shaft412and a link center hole422may be respectively formed at the center portions of the front first link410and the front second link420, and the link center shaft412and the link center hole422may have shapes corresponding and be rotatably coupled to each other. As shown in the drawing, in the present disclosure, the case in which the link center shaft412is formed in the front first link410and the link center hole422is formed in the front second link420is illustrated. In other words, the link center shaft412may protrude forward or rearward from a center portion of the front surface or the rear surface of the front first link410, and the link center hole422may be formed on the center portion of the front second link420by being perforated forward and rearward, so that the link center shaft412of the front first link410may be rotatably installed by being inserted into the link center hole422of the front second link420.

Likewise, the link center shaft412and the link center hole422may be respectively formed in the center portions of the rear first link430and the rear second link440, and the link center shaft412and the link center hole422may have the shapes corresponding to each other and be rotatably coupled to each other. As shown in the drawing, in the present disclosure, the case in which the link center shaft412is formed in the rear first link430and the link center hole422is formed in the rear second link440is illustrated.

First link holes414may be respectively formed in upper ends of the front first link410and the rear first link430by being perforated forward and rearward, and the right upper link shafts557of the fixed bracket550may be rotatably inserted into and coupled to the first link holes414.

Second link holes424may be respectively formed in upper ends of the front second link420and the rear second link440by being perforated forward and rearward, and the left upper link shafts566of the moving bracket560may be rotatably inserted into and coupled to into the second link holes424.

First link protrusions416may protrude forward or rearward from lower ends of the front first link410and the rear first link430, and the first link protrusions416may be connected to the link frame450.

Second link protrusions426may protrude forward or rearward from lower ends of the front second link420and the rear second link440, and the second link protrusions426may be connected to the link frame450.

The link frame450may include a bottom part454, link connection ends456, etc., as shown in the drawing, and the bottom part454may consist of a flat plate having a predetermined thickness, and the link connection ends456may extend by being perpendicularly bent upward from a front end and a rear end of the bottom part454.

The lower ends of the front first link410and the rear first link430and the lower ends of the front second link420and the rear second link440may be rotatably coupled to the link connection ends456, respectively.

As shown in the drawing, the first link protrusion holes452may be formed in left half parts of the link connection ends456by being perforated forward and rearward, the first link protrusions416formed in the lower ends of the front first link410and the rear first link430may be accommodated therein.

s shown in the drawing, preferably, the first link protrusion holes452may be formed to have predetermined transverse lengths, and preferably, the first link protrusions416may be transversally movable while being accommodated in the first link protrusion holes452.

First link protrusion grooves452amay be respectively formed by being depressed downward from left and right ends of each of the first link protrusion holes452. The first link protrusion grooves452amaintains a situation in which the moving assembly200moves vertically and then is temporarily stopped, and serves as a portion where the first link protrusions416temporarily stay.

As shown in the drawing, second link protrusion holes458may be formed in right half portions of the link connection ends456by being perforated forward and rearward, and the second link protrusions426formed in the lower ends of the front second link420and the rear second link440may be accommodated therein.

According to the above structure, the second link protrusions426maintain the state of being accommodated in the second link protrusion holes458, and the first link protrusions416are transversally rotatable while being accommodated in the first link protrusion holes452, so that the lower ends of the front first link410and the rear first link430may move closer to or away from the lower ends of the front second link420and the rear second link440and thus the link connection ends456may move vertically.

Meanwhile, it is preferable that the height at which the heater210descends inside the cooking chamber may be arbitrarily set. That is, the height at which the heater210descends inside the cooking chamber or the height at which the heater210is positioned at the time of cooking in the cooking chamber may be set by the user or the designer. That is, it is preferable that the descending height of the heater210, which descends inside the cooking chamber due to the rotation (forward or reverse rotation) of the motor510, or the moving assembly200on which the heater210is installed, may be set by the user or the like.

In addition, the height at which the heater210or the moving assembly200descends inside the cooking chamber may be set to 2 or more. That is, the height at which the heater210or the moving assembly200descends is set in advance, and the user may automatically lower the heater210or the moving assembly200to a predetermined height by selecting the set position, thereby performing cooking.

FIGS.26and27show a state in which the link assembly400moves up and down by rotation of the motor510. That is,FIG.26is a perspective view illustrating a coupling state of the link assembly400and the moving control means500, andFIG.27illustrates a state in which the heater210is positioned at a specific height in the cooking chamber.FIG.27(a)is a front view showing a state of the link assembly400when the heater210and the moving assembly200are positioned at an upper end of the cooking chamber, andFIG.27(b)is a front view showing a state of the link assembly400when the heater210and the moving assembly200are lowered at a first position in the cooking chamber, andFIG.27(c)is a front view illustrating a state of the link assembly400when the heater210and the moving assembly200are lowered at a second position in the cooking chamber.

As shown inFIG.27, when the link assembly400is operated by the rotation of the motor510, the moving assembly200coupled to the link frame450of the link assembly400moves vertically in the cooking chamber, and as a result, the heater210moves up and down inside the cooking chamber and reaches a specific position to perform cooking.

For example,FIG.27(a)shows a state in which upper and lower ends of each link are close to each other, which may indicate a state in which the heater210and the moving assembly200are located at the original upper end portion inside the cooking chamber. That is, the height at which the heater210and the moving assembly200descend to the inside of the cooking chamber may be 0 mm.

FIG.27(b)shows a state in which the heater210and the moving assembly200reach the first position set by a designer or a user. That is, the height at which the heater210and the moving assembly200descend into the cooking chamber may be 46 mm. As described above, when the heater210descends inside the cooking chamber, the heater210may become closer to the food and the cooking efficiency may be improved.

FIG.27(c)shows a state in which the heater210and the moving assembly200reach the second position set by the designer or the user. That is, the height at which the heater210and the moving assembly200descend into the cooking chamber may be 92 mm. Of course, the descending height should be set to a smaller size than the height of the inside of the cooking chamber. Accordingly, when the heater210descends inside the cooking chamber, the heater210may become closer to the food and the cooking efficiency may be improved.

When cooking is performed by reaching the predetermined height, the heater210and the moving assembly200are raised to the upper end of the cooking chamber to be placed in the original position, and in this case, the original position of the heater210or the moving assembly200may be detected by an original position detection means.

FIGS.28and29show the configuration and the installation state of the original position detection means for detecting whether the heater210or the moving assembly200is positioned at the original position. That is,FIG.28is a partial cross-sectional view illustrating a state in which the original position detection means is installed at one side of the casing10, andFIG.29is a partially enlarged view illustrating the configuration and an operation state of the original position detection means.

As shown in these figures, the movable heater system100may be provided with an original position detection means395for detecting whether the heater210is positioned at the original position.

The original position detection means395may comprise: a position switch390provided at one side of the movable heater system100; a position lever394for selectively pressing a position button392of the position switch390; and a position member470for selectively pushing the position lever394according to the vertical movement of the heater210.

As described above, the position switch390may be installed in the position bracket380, and the position lever394may also be installed in the position bracket380. Of course, although the position lever394may be installed at another portion other than the position bracket380, the present disclosure illustrates a case in which the position lever394is installed at the position bracket380together with position switch390vertically.

As described above, the position member470may be installed at the link assembly400. That is, the position member470may be installed to protrude upward from the upper surface of the link frame450by a predetermined height to selectively interfere with the position switch390. Of course, the position member470may also be installed in the moving assembly200other than the link frame450.

The position lever394may be formed to have elasticity due to its own material or shape. That is, the position lever394is formed to have a predetermined length, and may have elasticity or may be made of an elastic material so that bending may occur by the shape of the position lever394having a predetermined length.

In addition, the position lever394may have a shape that is bent more than once as shown.

Specifically, the position lever394includes: a contact end394afor directly or indirectly pressing the position button392of the position switch390; an interference part394bin which one end of the position member470is selectively in contact; a connection part394cprovided between the contact end394aand the interference part394b; a fixed part394dfixedly mounted to the position bracket380; and a coupling part394econnecting the fixed part394dand the interference part394b.

The contact end394ais formed at the end of the position lever394(right end inFIG.29), and presses the position button392provided in the position switch390or a guide lever392b, which will be described below, upward (inFIGS.28and29).

As illustrated, the fixed part394dmay have a circular ring shape, and may be fixedly installed on the position bracket380.

The coupling part394eprotrudes from one side (right downward inFIG.29) from the fixed part394d, and the right end thereof (inFIG.29) is integrally connected to the interference part394b.

The interference part394bis horizontally installed as shown in a portion that is selectively in direct contact with the upper end of the position member470. This is to be movable upward by the upper end of the position member470.

The connection part394cfurther extends to the right from the right end of the interference part394band is preferably bent at a predetermined angle with respect to the interference part394b. That is, as shown inFIG.29, the right end of the connection part394cis positioned above the left end (inFIG.29).

As shown inFIG.29, the contact end394amay be integrally formed at an end (right end ofFIG.29) of the connection part394c, and may be formed to be horizontal to easily push the position button392or the guide lever392b.

The position switch390may be a micro switch. Accordingly, the position switch390may include one or more terminals392aand the position button392. The position button392is generally called an actuator, and is a mechanism for opening and closing the switch by receiving external force directly or indirectly to operate the switch and transferring the operation therein.

The position switch390may further include the guide lever392binstalled to have elasticity and being in direct contact with the position button392. The guide lever392bmay be formed to have a predetermined length, and may be made of a metal material or the like to have elasticity.

When the guide lever392bis provided in the position switch390as described above, the contact end394aof the position lever394may press the guide lever392bwithout directly pressing the position button392.

Meanwhile, when the position switch390does not include the guide lever392b, the position lever394may directly press the position button392. When the position switch390includes the guide lever392b, the position lever394presses the guide lever392bso that the position button392is pressed by the guide lever392b.

The moving assembly200and the heater210described above may move vertically inside the cooking chamber by the rotation of the motor510constituting the moving control means500.

The movement of the moving assembly200and the heater210may be configured to be stopped when the position button392of the position switch390is pressed. That is, when the moving assembly200and the heater210, which have descended into the cooking chamber are raised, the moving assembly200or the position member470, which is installed in the link assembly400, also ascends.

Accordingly, when the position member470presses the position lever394upward, the position lever394or the guide lever392bpushes the position button392upward so that the position switch390is turned on. When the position switch390is turned on, the upward movement of the moving assembly200and the heater210may be stopped.

Of course, even when the position switch390is turned on, the upward movement of the moving assembly200may be set to be further maintained for a predetermined time. That is, the motor510may be set to be stopped after being further operated for a predetermined time even after the position button392of the position switch390is pressed and turned on. This is to prevent leakage of microwaves by effectively blocking a gap between the moving assembly200and the upper surface of the cooking chamber.

Specifically, the cooking appliance according to the present disclosure is configured to enable cooking by a microwave wave, and the microwave is preferably set to be operated only when the moving assembly200and the heater210are accurately returned to the original position and the position switch390is turned on. That is, in order to operate the microwave in the cooking appliance according to the present disclosure, it is preferable that the moving assembly200or the heater210is in its original position.

This is because the microwave inside the cooking chamber is prevented from leaking to the outside. In a state in which the moving assembly200is lowered into the cooking chamber, microwaves are leaked to the outside through a gap between the moving assembly200and the upper plate310that is an upper surface of the cooking chamber.

Therefore, in the cooking apparatus according to the present disclosure, the microwave may be set to operate when the moving assembly200reaches the upper end of the inside of the cooking chamber and the upper plate310and the insulating member230of the moving assembly200come into contact with each other to shield the gap between the moving assembly200and the upper plate310.

Furthermore, even when the position button392is pressed and the position switch390is turned on, the moving assembly200may be set to move upward by a predetermined distance, and this is also to completely shield the gap between the upper plate310and the moving assembly200.

For example, when the gap (G) between the lower surface of the upper plate310and the upper surface of the insulating member230of the moving assembly200reaches 0.5 mm, the position switch390is set to be turned on and the motor510is additionally set to be further rotated by 29° even after the position switch390is turned on. In this case, the lower surface of the upper plate310and the upper surface of the insulating member230of the moving assembly200are completely in close contact with each other to prevent the leakage of microwave through the gap (G).

More specifically, with reference to the drawingFIG.29, when the moving assembly200and the heater210are lowered inside the cooking chamber12, the contact end394a, which is an end of the position lever394, is located at a point ‘A’.

When the upper end of the position member470pushes the interference part394bof the position lever394upward according to the ascending of the moving assembly200and the heater210, the contact end394aof the position lever394reaches the point ‘B’ and presses the position button392so that the position switch390is turned on.

In this state, when the gap (G) between the lower surface of the upper plate310and the upper surface of the insulating member230reaches 0.5 mm, and the motor510is additionally rotated by 29°, the upper end of the position member470further pushes the interference part394bof the position lever394by a predetermined height upward, such that the gap (G) between the upper plate310and the insulating member230becomes almost zero (0).

When the guide lever392bis provided, the contact end394aof the position lever394directly presses the position button392through the guide lever392binstead of directly pressing the position button392.

Meanwhile, in the present disclosure, a shielding structure is added for shielding electromagnetic waves leaking from the cooking chamber inside the cooking appliance to the outside. That is, when the microwave is operated in the cooking appliance according to the present disclosure, an electromagnetic wave is generated, and the electromagnetic wave may leak to the outside through a gap around the moving assembly200. Therefore, a shielding structure for shielding the leakage of the electromagnetic wave is required.

FIGS.30and31illustrate a configuration of the shielding means260for preventing electromagnetic wave leakage through a gap between the casing10and the moving assembly200.FIG.30is a cut-away perspective view illustrating a configuration of the movable heater system100, andFIG.31is a partial cross-sectional view illustrating a configuration of the shielding means260for shielding electromagnetic wave leakage.

As shown in the drawings, when the heater210is located at an upper end portion of the cooking chamber, the shielding means260may be provided for shielding electromagnetic waves inside the cooking chamber from leaking to the outside, and the shielding means260may include the insulating member230and the protection cover320described above.

The shielding means260functions to prevent electromagnetic wave leakage through the gap between the casing10and the moving assembly200when the heater210and the moving assembly200are positioned in its original location.

As described above, the insulating member230may be provided at a lower end of the moving assembly200and may be installed such that an outer edge thereof protrudes further outward than the moving assembly200.

As described above, the protection cover320may be provided in the casing10to surround the moving assembly200from the side.

The insulating member230and the protection cover320may have a structure in which a predetermined portion thereof vertically overlaps. That is, when the moving assembly200and the heater210are positioned in its original location, the insulating member230and the protection cover320are preferably partially overlapped with each other. This is to prevent electromagnetic waves in the cooking chamber from leaking due to the overlap between the insulating member230and the protection cover320.

The shielding means260may be provided with resonance chambers262,264for trapping or offsetting the electromagnetic waves. That is, the insulating member230or the protection cover320may be provided with resonance chambers262,264for trapping or offsetting electromagnetic waves, and the resonance chambers262,264may be formed on both the insulating member230and the protection cover320.

In the present disclosure, the resonance chambers262,264are formed on both the insulating member230and the protection cover320. That is, as illustrated, a first resonance chamber262is formed in the insulating member230, and a second resonance chamber264is formed in the protection cover320.

The first resonance chamber262and the second resonance chamber264may be formed in a passage of electromagnetic waves passing through a gap around the moving assembly200, and may be formed to have a space of a predetermined size as illustrated.

In addition, when the moving assembly200and the heater210are raised (in the original position), it is preferable that the insulating member230and the upper plate310overlap or be in contact with each other, and at least the insulating member230and the upper plate310are controlled to operate in a state in which the insulating member230and the upper plate310are close to each other to shield the electromagnetic wave leakage. That is, it is preferable that the microwave is operated only when the upper surface of the insulating member230at the lower end of the moving assembly200is in contact with the lower surface of the upper plate310as the moving assembly200rises, or the microwave is controlled to operate in a state where at least the insulating member230and the upper plate310are close to each other to shield the electromagnetic wave leakage.

The contact or proximity control of the insulating member230and the upper plate310may be performed by an original position detection means395for detecting whether the heater210is positioned at the original position. Therefore, it is preferable that the microwave is operated only when the contact or proximity of the insulating member230and the upper plate310is confirmed by the original position detection means395.

FIG.32illustrates a configuration of a food detection system375constituting the cooking appliance according to the present disclosure.

The food detection system375may be provided in the casing10to detect whether the moving assembly200interferes with food inside the cooking chamber12.

The food detection system375may include the moving control means500and the protection switch370described above. That is, the food detection system375may include the moving control means500for restraining the moving assembly200to move vertically, and the protection switch370turned on/off by the moving control means500.

As illustrated, the protection switch370and the protection lever372are mounted on the protection bracket360, and the protection lever372is preferably positioned between the protection switch370and the lead screw520.

Although not shown in detail, an additional guide lever374such as the guide lever392bof the position switch390may be further provided in the protection switch370to directly contact the protection button370a.

As described above, the protection switch370may be installed to be spaced apart from one end (left end ofFIG.32) of the lead screw520by a predetermined distance.

The distance between one end (the left end ofFIG.32) of the lead screw520and the protection switch370or the protection lever372may be smaller than the extendable distance of the connection coupling540.

Specifically, in the present disclosure, since the protection lever372is installed between the protection switch370and the lead screw520, the distance (L) between the protection lever372and the left end of the lead screw520is preferably smaller than the length of the connection coupling540formed by the flexible coupling extending in the left and right directions.

This is to allow the protection switch370to be turned on before the connection coupling540is damaged when the lower end of the moving assembly200is interfered (contact) with the food and the connection coupling540is extended.

For example, when the extension length of the connection coupling540, that is, the limit of the tensile change of the elastic limit of the connection coupling540is 2.5 mm, the distance (L) between the protection lever372and the left end of the lead screw520may preferably be about 1.7 mm. This is because the distance (L) between the left end of the lead screw520and the protection lever372is sufficiently smaller than the elastic limit of the tensile change of the connection coupling540, so that there is no risk of damage.

The protection switch370and the protection lever372may have the same configuration as the position switch390and the position lever394described above.

Accordingly, the protection switch370may include the protection button370aand one or more terminals370b. The protection button370ais also referred to as an actuator, and is a mechanism for opening and closing the switch by receiving external force directly or indirectly to operate the switch and transferring the operation therein.

The protection lever372may have elasticity like the position lever394and may be installed to directly contact the protection button370a. That is, the protection lever372may be formed to have elasticity due to its own material or shape, and the lower end of the protection lever372may be installed to directly contact and push the protection button370a.

In addition, the protection lever372may also have a shape bent one or more times like the position lever394.

The food and cooking apparatus may be prevented from being damaged by the food detection system375.

When the protection button370aof the protection switch370is pressed and turned on, the moving assembly200may be set to stop descending and raise again. Of course, when the protection button370aof the protection switch370is pressed and turned on, the moving assembly200may be set to stop descending and rise after a predetermined time elapses.

In addition, when the protection button370a of the protection switch370is pressed and turned on, a message or a signal for informing the food contact may be displayed or transmitted to the outside.

When the moving assembly200descends inside the cooking chamber12and is in interference with the food inside the cooking chamber12, the lead nut530is stopped when the lead screw520is rotated. Therefore, since the moving assembly200cannot continue moving downward, the lead screw520continuously moves to the left by the rotation of the motor510, thereby turning on the protection switch370.

Hereinbelow, the operation of the cooking appliance according to the present disclosure having the above-described structure will be described with reference to the accompanying drawings.

First, as shown inFIG.1, before cooking starts with the movable heater system100installed at the upper surface of the casing10, as shown inFIGS.2to7, the moving assembly200of the movable heater system100may be located at the upper end of the cooking chamber12.

Therefore, at this time, since the moving assembly200is raised to the upper side, the first link protrusions416of the front first link410and the rear first link430may be located at left ends of the first link protrusion holes452of the link frame450.

In this state, when the lead nut530moves gradually rightward in response to rotation (forward rotation) of the motor510, the upper ends of the front first link410and the front second link420and the upper ends of the rear first link430and the rear second link440may move closer to each other, so that the moving assembly200may moves to the lower space in the cooking chamber12.

Meanwhile, when the moving assembly200crashes with the food in the cooking chamber12while being lowered in the cooking chamber12, the moving assembly200can no longer be lowered, so that the lead nut530may be restrained. As described above, when the motor510continues forward rotation and movement of the lead nut530stops, tension is generated in the connection coupling540in response to rotation of the lead screw520, and the left end of the lead screw520may stretch leftward.

When the left end of the lead screw520moves leftward by a predetermined distance, the protection switch370installed adjacent to the lead screw520is operated so that the rotation of the motor510stops. By the above-described process, a damage to the parts such as the connection coupling540in addition to the food in the cooking chamber12is prevented.

Specifically, when the moving assembly200descends inside the cooking chamber12and collides with the food inside the cooking chamber12so that the moving assembly200may no longer descend, the lead nut530may no longer move left and right because it is mounted on the fixed bracket560.

However, even at this time, since the motor510continues to rotate forward, the lead screw520moves to the left (seeFIG.32), and the left end of the lead screw520pushes the protection lever372to the left. When the lead screw520pushes the protection lever372to the left, the lower end of the protection lever372presses the protection button370aof the protection switch370, so that the protection switch370is turned on.

When the protection switch370is turned on, the forward rotation of the motor510is stopped so that the descending of the moving assembly200is stopped.

Thereafter, the motor510may perform an immediate reverse rotation, such that the moving assembly200may ascend, or the moving assembly200may ascend after a predetermined time elapses. A reverse rotation time point of the motor510may be changed by setting.

In addition, when the protection switch370is turned on and the forward rotation of the motor510is stopped, a message or signal is displayed or transmitted to the outside for the user to recognize the food contact.

The movable heater system100with the moving assembly200moving downward below the upper plate310and lowered into the inside space of the cooking chamber12is shown inFIGS.8to11.

At this time, the first link protrusions416of the front first link410and the rear first link430may be located at the right ends of the first link protrusion holes452of the link frame450.

When the moving assembly200is lowered inside the cooking chamber12, the heaters210may move closer to the food inside the cooking chamber12so that cooking of the food can be performed more rapidly.

When the cooking is completed in the above-described state, the moving assembly200may be raised and be recovered to the original position thereof. For raising of the moving assembly200, the motor510should be controlled to perform reverse rotation, and when the lead nut530is moves gradually leftward by the reverse rotation of the motor510, the upper ends of the front first link410and the front second link420the upper ends of the rear first link430and the rear second link440may move away from each other so that the moving assembly200may move upward of the cooking chamber12and be recovered to the original position.

The position member470, the position switch390, etc. may detect whether or not the moving assembly200is raised and recovered to the original position thereof. when the gap between the insulating member230of the moving assembly200and the upper plate310is less than or equal to a preset gap, the upper end of the position member470provided in the moving assembly200may operate the position switch390so that the motor510may be controlled to stop.

By the control, a crash between or damages to the upper plate310and the insulating member230can be prevented and leakage of electromagnetic waves via the gap between the upper plate310and the insulating member230can be prevented.

Furthermore, only when the moving assembly200is recovered to the original position thereof by the position switch390, use of electromagnetic waves of the cooking appliance is controlled to be possible. Therefore, when the moving assembly200is lowered downward into the cooking chamber12, since the use of electromagnetic waves of the cooking appliance is blocked, so that the leakage of electromagnetic waves is prevented.

Specifically, as described above, only when the moving assembly200reaches the upper end of the cooking chamber and the upper plate310and the insulating member230of the moving assembly200are in contact with each other, the microwave is controlled to operate.

In addition, when the gap (G) between the lower surface of the upper plate310and the upper surface of the insulating member230of the moving assembly200reaches 0.5 mm, the position switch390is turned on, and the motor510is additionally rotated (about) 29° even after the position switch390is turned on, so that the lower surface of the upper plate310and the upper surface of the insulating member230of the moving assembly200are completely in close contact, so that the microwave operation may be set only in this case.

In the present disclosure, a path through which an electromagnetic wave leaks during the microwave operation is shown by arrows inFIGS.30and31. That is, the electromagnetic waves inside the cooking chamber12flow through the gap between the upper plate310and the insulating member230, are primarily offset in the first resonance chamber262, and then move upward through the gap between the choke piece314and the moving assembly200. In this process, electromagnetic waves flow through the choke groove314bof the choke piece314or the gap hole314aand are dispersed or secondly offset by interference with each other, and then flow into the second resonance chamber264of the protection cover320and are thirdly offset. Then, they may flow upward through the gap between the protection upper end part328of the protection cover320and the heater housing220of the moving assembly200.

Such electromagnetic waves inside the cooking chamber12pass through the gap between the upper plate310and the insulating member230, the gap between the heater housing220of the moving assembly200and the insulating member230and the protection cover320, and the first resonance chamber262and the second resonance chamber264, etc., they almost disappear, thus preventing leakage to the outside of the cooking appliance.

The scope of the present disclosure is not limited to the above illustrated embodiment, and those skilled in the art will appreciate that various modifications, additions and substitutions based on the present disclosure are possible, without departing from the scope and spirit of the present disclosure.

For example, in the above embodiment, the protection lever372is installed between the protection switch370and the lead screw520, so that the protection lever372directly presses the protection button370aof the protection switch370, but the lead screw520may be configured to directly press the protection button370aof the protection switch370.