KR20000075155A - Microwave oven having a heater - Google Patents

Abstract

PURPOSE: A microwave oven is provided to uniformly heat food stuff by preventing a radiant heat of a heater from being directly transferred to the food in a convection mode. CONSTITUTION: A microwave oven comprises a main body(120) having a cooking chamber(101) and a rear plate(122) with a plurality of vent holes(123); a high frequency generator for generating a high frequency and radiating the high frequency into the cooking chamber; a heater assembly having a heater(139) installed to be rotatable between a horizontal position facing an upper plate(124) of the cooking chamber and a vertical position facing the rear plate of the cooking chamber, and a member for rotating the heater; a convection fan assembly(141) installed in the rear of the rear plate of the cooking chamber and which generates convection current to the air within the cooking chamber via the vent holes formed at the rear plate; and a radiant heat shutoff member(150) for preventing the radiant heat of the heater from being transferred to the food stuff loaded in the cooking chamber when the heater is at a vertical position.

Description

Microwave oven having a heater {Microwave oven having a heater}

The present invention relates to a microwave oven having a combined grill mode and a convection mode heater, and more particularly, to an improved microwave oven capable of uniformly heating food by preventing radiant heat of the heater from being directly transmitted to the food in the convection mode.

A microwave oven is a device for cooking food using microwaves generated from a magnetron. The principle is that food is cooked from the inside by heating water molecules contained in the food. Such microwave ovens are widely used because of their high thermal efficiency, rapid cooking, and low loss of nutrients.

Recently, in addition to these basic functions, by using a separate heater to cook using the heat generated by the heater, a microwave oven is provided that can compensate for the disadvantages of cooking using high frequency and provide a variety of cooking functions to the user have. As described above, in a microwave oven having a heater, a method of cooking food using a heater includes a grill mode and a convection mode.

In the grill mode, since the radiant heat is directly transmitted to the food by heating the food by the radiant heat of the heater, the food is heated from the surface to the inside to brown the surface. The convection mode generates convection in the air inside the cooking chamber and heats the food by the air warmed by the radiant heat of the heater to transfer the heat energy to the food.

To this end, a microwave oven of a type having a grill mode heater and a convection mode heater separately, and a type of microwave using a single heater in both a grill mode and a convection mode have been provided.

5 is a cross-sectional view illustrating an example of a microwave oven in which a grill heater and a convection heater are separately installed, and FIG. 6 is a cross-sectional view illustrating an example of a microwave oven having a grill mode and a convection mode combined heater.

First, in the microwave oven in which the grill heater and the convection heater are separately installed, as shown in FIG. 5, the grill heater 22 is installed above the cooking chamber 12 in a horizontal state, and the cooking chamber 12 is disposed in the microwave oven. A convection heater 24 and a convection fan assembly 26 are installed at the rear side of the rear plate 13 of the inner body 11 to be formed. The convection fan assembly 26 has a motor 27, a convection fan 28, and a motor cooling fan 29. In addition, a heat insulating plate 19 for blocking heat generated from the convection heater 24 from being transferred to the motor 27 is provided on the rear plate 13 so that the convection fan 28 and the motor cooling fan 29 are positioned. It is installed. And, the back panel 18 is fixed to the back plate 13 so as to surround the convection fan assembly 26. A plurality of intake holes 14 and exhaust holes 15 are formed in the rear plate 13 to allow air to enter and exit between the cooking chamber 12 and the rear space 16 of the rear plate 13.

In the grill mode, electric power is applied to the grill heater 22, heat generated by the grill heater 22 is transferred to the food F by radiation, and the food F is heated. In the convection mode, electric power is applied to the convection heater 24 to generate heat to the convection heater 24, and the convection fan 28 of the convection fan assembly 26 is driven. Air inside the cooking chamber 12 is sucked into the space 16 between the rear plate 13 and the heat insulating plate 19 through the intake hole 14 of the rear plate 13 by the driving of the convection pan 28. The sucked air is heated by the heat of the convection heater 24, and the heated hot air is discharged to the cooking chamber 12 through the exhaust hole 15 of the rear plate 13. As described above, the food is heated by transferring heat energy of the convection heater 24 to the food F in the process of circulating the cooking chamber 12 and the rear plate rear space 16.

However, since the grill heater 22 and the convection heater 24 are separately installed, the microwave oven has a disadvantage in that the number of parts is increased and the size of the insulation plate 19 is increased, thereby increasing the manufacturing cost. In addition, since the space for installing the convection heater 24 is required, there is a disadvantage in that the total volume of the microwave is increased.

Therefore, recently, as shown in FIG. 6, a microwave oven that performs cooking in a grill mode and a convection mode using a single combined heater 22 ′ has been widely used. In the microwave oven of this type, the rear plate 13 'of the inner body 11' in which the grill mode and convection mode combined heater 22 'forms a horizontal position above the cooking chamber 12' and the cooking chamber 12 'is formed. It is rotatably installed between the vertical positions opposite to. This heater 22 'is rotated by a heater rotating mechanism (not shown). On the rear side of the back plate 13 ', a convection fan assembly 26' and a back panel 18 'are mounted. A plurality of intake holes 14 'and exhaust holes 15' are formed in the rear plate 13 'to allow air to enter and exit between the cooking chamber 12' and the rear space 16 'of the rear plate 13'. It is. Moreover, the heat insulation board 19 'is provided along the periphery of the back plate 13'. Here, since the heater 22 'is installed inside the cooking chamber 12', the distance between the heater 22 'and the motor 27' of the convection fan assembly 26 'is large so that the size of the insulation plate 19' is increased. Is smaller than the case of FIG. 5 in which the convection heater is separately installed.

In the grill mode, the heater 22 'is located at a horizontal position above the cooking chamber 12'. At this time, the convection fan assembly 26 'is not driven, and heat generated from the heater 22' is directly transmitted to the food F through radiation. In the convection mode, the heater 22 'is rotated by the rotating mechanism and positioned in a vertical position opposite to the rear plate 13'. In this case, the convection pan assembly 26 'is driven, and the air inside the cooking chamber 12' is circulated between the cooking chamber 12 'and the rear space 16' by the convection pan 28 ', and the heater ( 22 ') heat energy to the food (F) to heat the food (F).

However, in the microwave oven using the combined heater 22 'as described above, the heater 22' is positioned perpendicular to the rear side of the cooking chamber 12 'in the convection mode. That is, since the distance between the heater 22 'and the food F becomes close, and no member is provided between the heater 22' and the food F, the radiant heat of the heater 22 'is reduced even in the convection mode. The phenomenon is delivered directly to the food (F). Accordingly, in the convection mode, the food F is not uniformly heated, and the cooking speed is changed according to the portion, and the portion where the radiant heat is directly transmitted is excessively cooked and burned. In addition, there is a high possibility that the user's hand may be injured by the heater 22 'when the cooking is completed and the user takes out the food.

The present invention has been made in view of the above, it is possible to block the transfer of radiant heat of the heater directly to the food in the convection mode while using a grill and convection combined heater to achieve a uniform heating of food The purpose is to provide a stove.

1 is an exploded perspective view of a microwave oven according to an embodiment of the present invention.

Figure 2 is a bottom perspective view showing a radiant heat shield plate and a heater which is the main part of the present invention.

Figure 3 is a side cross-sectional view showing an operating state in the grill mode of the microwave oven according to an embodiment of the present invention.

Figure 4 is a side cross-sectional view showing an operating state in the convection mode of the microwave oven according to an embodiment of the present invention.

Figure 5 is a side cross-sectional view showing an example of a conventional microwave oven having a grill heater and a convection heater separately.

Figure 6 is a side cross-sectional view showing an example of a conventional microwave oven having a grill mode and a convection mode combined heater.

Explanation of symbols on the main parts of the drawings

101; Cooking chamber 112; Outer body

114; Door 116; Operation panel

118; Back panel 120; Inner body

122; Backplane 123; Aeration

124; Top plate 126; Right side plate

132; Magnetron 139; heater

141; Convection fan assembly 142; Convection fan

143; Convection motor 150; Radiant heat shield

152; Coupling member 154; Intake

156; Vent

The above object has a cooking chamber for cooking food, the back plate forming the cooking chamber body formed with a plurality of ventilation holes; A high frequency generator for generating a high frequency wave to irradiate the inside of the cooking chamber; A heater assembly having a heater rotatably provided between a horizontal position above the cooking chamber and a vertical position opposite the rear plate, and a rotating mechanism for rotating the heater; A convection fan assembly installed at a rear side of the rear plate and configured to generate convection to air in the cooking chamber through an air vent of the rear plate; And when the heater is in a vertical position, it is achieved by the microwave oven according to the present invention comprising a radiation heat shield for blocking the heat transfer of the heater directly to the food placed inside the cooking chamber.

The radiant heat shield is provided with a radiant heat shield plate having a plurality of intake and exhaust holes facing the back plate with the heater therebetween when the heater is in the vertical position and passing air flowing by the convection fan assembly; It includes a plurality of coupling members for coupling the radiant heat shield plate to the heater to be rotated with the heater. The plurality of intake holes are formed in the center portion of the radiation shield, and the plurality of exhaust holes are formed along the outer circumference of the radiation shield. The coupling member is a ring-shaped member fixed to the radiation shielding plate and open at one side thereof so that one side of the heater is fitted therein.

According to this, since the radiant heat of the heater is directly prevented from being transmitted to the food by the radiant heat blocking plate when cooking in the convection mode, the food is cooked only by the heat of the air flowing by the convection pan assembly. Therefore, the food is cooked uniformly throughout.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

A microwave oven according to an embodiment of the present invention is shown in FIG. 1.

As shown, the microwave oven is composed of various electrical components installed between the inner body 120 and the outer body 112 and the inner and outer bodies 120 and 112. The inner body 120 is partitioned into the cooking chamber 101 and the electric compartment 102 by its right side plate 126. The upper plate 124 of the inner body 120 is installed only on the upper side of the cooking chamber 101. The door 114 is attached to the front surface of the cooking chamber 101, and the operation panel 116 is attached to the front surface of the electric compartment 102.

The convection fan assembly 141 and the back panel 118 are mounted on the rear side of the back plate 122 of the inner body 120, respectively. In addition, the circumference of the rear plate 122 is provided with a heat insulating plate 119 having a 'ㅁ' shape. In addition, a plurality of vent holes 123 are formed to allow air to enter and exit between the cooking chamber 101 and the rear space 103 of the rear plate 122. The convection fan assembly 141 includes a convection fan 142 causing convection between the cooking chamber 101 and the rear plate rear space 103, a convection motor 143 for driving the convection fan 142, and a convection motor 143. ) And a bracket 145 for fixing the motor cooling fan 144 coaxially with the convection fan 142 and the motor 143 to the back panel 118.

The electrical equipment room 102 generates a high frequency and supplies a high frequency component to be supplied to the cooking chamber 101, that is, a magnetron 132 for generating a high frequency, a high voltage transformer 134 for driving the magnetron 132, and a high voltage diode 135. ), A high-pressure condenser 136, a waveguide for guiding the high frequency generated from the magnetron 132 to the cooking chamber 101, and a cooling fan 137 for cooling the components inside the electrical chamber 102 are installed. It is.

The lower side of the cooking chamber 101 is provided with a rotating plate 138 on which food F is placed, and a drive motor 146 for driving the rotating plate, and a heater assembly is provided above the cooking chamber 101. . The heater assembly is composed of a heater 139, a rotating mechanism (not shown) for rotating the heater 139, and a radiation shield plate 150. The heater 139 is rotatably provided between a horizontal position facing the top plate 124 of the cooking chamber 101 and a vertical position facing the rear plate 122 of the cooking chamber 101. The heater rotating mechanism rotates the heater 139 between the horizontal position and the vertical position according to the cooking mode, and can be manually operated or automatically operated. The detailed structure of the heater rotating mechanism is beyond the scope of the present invention, and can be easily implemented from US Patent No. 5,793,023 or US Patent No. 5,534,681 to the present applicant, and thus, detailed descriptions of the illustration and operation will be given herein. Omit.

The radiation shield 150 is coupled to the upper side of the heater 139 through a plurality of coupling members 152, as shown in more detail in FIG. The coupling member 152 is a ring-shaped member having one side fixed to the inner surface of the radiation shielding plate 150 opened, and the heater 139 is fitted through the opening to be coupled. The radiation shield plate 150 has a plurality of intake holes 154 formed in the center portion thereof, and a plurality of exhaust holes 156 formed along its outer circumference.

When the heater 150 is positioned in the horizontal position, the radiation shield plate 150 is positioned between the heater 139 and the top plate 124 of the inner body 120. In this case, the radiant heat shield plate 150 reflects the radiant heat of the heater 139 downward.

When the heater 139 is rotated and positioned in a vertical position, the radiant heat shield plate 150 faces the rear plate 122 of the inner body 120 with the heater 139 interposed therebetween. The air circulated by the convection fan assembly 141 enters and exits between the cooking chamber 101 and the rear plate rear space 103 through the intake hole 154 and the exhaust hole 156 of the radiant heat shield plate 150.

The operation in the grill mode and the convection mode of the microwave oven according to an embodiment of the present invention having the above configuration is as follows.

When cooking in the grill mode, the heater 139 is positioned in a horizontal position above the cooking chamber 101 as shown in FIG. 3, and the radiant heat blocking plate 150 is the top plate 124 and the heater 139 of the cooking chamber 101. Is located between. Therefore, when the heater 139 is operated to generate heat from the heater 139, the radiant heat generated by the heater 139 is transferred to the food F placed in the rotary plate 138 below the food F. Heated. In the grill mode as described above, the surface of the food F is browned by radiant heat.

In cooking in the convection mode, the heater 139 is placed in a vertical position opposite to the back plate 122 of the inner body 120 as in FIG. 4. In this case, the radiation shield plate 150 is opposed to the rear plate 122 with the heater 139 therebetween. In the convection mode, the convection fan 142 of the convection fan assembly 141 is activated with the operation of the heater 139. According to the operation of the convection pan 142, the air inside the cooking chamber 101 passes through the rear plate rear space 103 through the intake hole 154 of the radiant heat shield plate 150 and the vent hole 123 of the back plate 122. After being introduced into and then discharged into the cooking chamber 101 through the vent hole 123 of the rear plate 122 and the exhaust hole 156 of the radiation shielding plate 150, it is circulated as indicated by the arrow. Air is heated by the heater 139 when passing between the radiant heat shield plate 150 and the back plate 122, the heated hot air transfers its heat energy from the cooking chamber 101 to the food (F) to food (F) )). On the other hand, the radiant heat generated by the heater 139 is not transmitted to the cooking chamber 101 by the radiant heat blocking plate 150 is reflected to the back plate 122 side. Therefore, radiant heat of the heater 139 is not directly transmitted to the food F of the cooking chamber 101, but heats the air around the heater 139. As a result, the food F is heated evenly as a whole because it is heated only by thermal energy due to air convection.

The grill mode or the convection mode as described above may be performed alone, or may be performed together with high frequency heating by driving the magnetron 132.

According to the present invention as described above, since the radiant heat blocking plate coupled to the heater blocks the radiant heat of the heater directly transmitted to the food when the convection mode cooking, the heater of the same heater as in the conventional grill and convection combined heater is installed. The effect of radiant heat is eliminated. Therefore, even in a microwave oven in which a grill and a convection combined heater are installed, there is an advantage in that food may be uniformly cooked as a whole when cooking in a convection mode. In addition, even when the user takes out food after the cooking is completed, the user's hand does not directly touch the heater, thereby preventing the user's hand from being injured by the heater. In addition, since the radiant heat of the heater radiated upward is also reflected downward by the radiant heat shielding plate when cooking in the grill mode, the cooking efficiency in the grill mode can be further improved.

In the above, the present invention has been illustrated and described with respect to certain preferred embodiments. However, the present invention is not limited only to the above-described embodiments, and those skilled in the art to which the present invention pertains can variously change without departing from the gist of the technical idea of the present invention described in the claims below. Could be done.

Claims (4)

It has a cooking chamber for cooking food, the back plate to form the cooking chamber body formed with a plurality of ventilation holes; A high frequency generator for generating a high frequency wave to irradiate the inside of the cooking chamber; A heater assembly having a heater rotatably provided between a horizontal position above the cooking chamber and a vertical position opposite the rear plate, and a rotating mechanism for rotating the heater; A convection fan assembly installed at a rear side of the rear plate to generate convection to air in the cooking chamber through an air vent of the rear plate; And And means for blocking the radiant heat of the heater from being directly transmitted to the food placed inside the cooking chamber when the heater is in the vertical position. The method of claim 1, wherein the radiant heat blocking means A radiation shielding plate having a plurality of intake and exhaust holes facing the back plate with the heater therebetween when the heater is in a vertical position and allowing air to flow through the convection fan assembly; And a plurality of coupling members for coupling the radiant heat shield plate to the heater such that the radiant heat shield plate rotates together with the heater. The microwave oven according to claim 2, wherein the plurality of intake holes are formed at the center of the radiation shielding plate, and the plurality of exhaust holes are formed along the outer circumference of the radiation shielding plate. 3. The microwave oven according to claim 2, wherein the coupling member is a ring-shaped member fixed to the radiation shielding plate and open at one side thereof so that one side of the heater is fitted therein.