JP2005106362A - High-frequency cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-frequency cooker uniformizing temperature of a food placing table approximately, and capable of suppressing an uneven cooking finish state. <P>SOLUTION: This high-frequency heating cooker is provided with a magnetron supplying a microwave to inside of a heating chamber and heating food by the microwave, the food placing table capable of being stored inside the heating chamber and having a heating member which absorbs the microwave and generates heat, and a control part for controlling driving of the magnetron. The control part performs a preheating process and a cooking process when roasting of the food is performed by using the food placing table, drives the magnetron by high output in the first half of the preheating process, and drives the magnetron by reducing output of the magnetron in the second half. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a high-frequency heating cooker.

  Conventionally, it has been well known that food is cooked using a food table provided with a heat generating member that generates heat by absorbing microwaves.

In addition, in the preheating process, first, in the preheating process, only the food mounting table is stored in the heating chamber, the food mounting table is heated and preheated, and then the food is placed on the food mounting table and the food is placed on the food mounting table. It is cooked over a dark surface. (For example, see Patent Document 1)
JP 2003-222340 A

  However, in the heating member of the food mounting table, microwaves are not uniformly distributed in the heating chamber, and unevenness in heating output occurs. Along with this, also in the heat generating member, a high temperature portion and a low temperature portion are generated depending on the location, and so-called heating unevenness in which the temperature distribution is not uniform has occurred.

  For this reason, for example, when fried eggs are cooked, there are places that are baked well and those that are half-life, and the finish is not so good.

  The present invention has been made to solve such problems.

  The high-frequency cooking device of the present invention includes a heating chamber that can store food, a magnetron that supplies microwaves to the heating chamber to microwave-heat the food, and can be stored in the heating chamber. A food placing table having a heat generating member that absorbs and generates heat; and a control unit that controls driving of the magnetron, and the control unit preheats when the food is baked using the food placing table. In the preheating process, the magnetron is driven at a high output in the preheating process, and the output of the magnetron is lowered and driven in the preheating process.

  According to the present invention, the temperature of the food mounting table becomes substantially uniform, and uneven cooking finish can be suppressed.

  Hereinafter, a microwave oven according to an embodiment of the present invention will be described with reference to the drawings.

  In FIG. 1, 1 is a microwave oven body, 2 is an exterior, 3 is a door that can be opened vertically with the lower part as a pivot, 4 is a handshake provided on the door 3, and 5 is an operation unit for inputting a start operation and cooking conditions. The operation unit 5 includes a key input unit 6 and a display unit for displaying input contents.

  In FIG. 2, 7 is a heating chamber provided in the exterior 2, 8 is a magnetron that oscillates microwaves, supplies microwaves into the heating chamber 7, and 9 is a waveguide that propagates microwaves oscillated by the magnetron 8. A tube 10 is rotatably disposed at the bottom of the heating chamber 7, and a rotating antenna that radiates and diffuses microwaves in the waveguide 9 into the heating chamber. 11 has a rotating shaft connected to the rotating antenna 10. An antenna motor 12 for rotating the antenna 10 is a ceramic bottom plate that partitions the bottom of the heating chamber 7 in which the rotary antenna 10 is arranged and can be placed with food.

13 is a rail provided so that a food tray can be stored in the heating chamber 7, a food tray placed on the rail 13 and stored in the heating chamber 7, and 16 a heating chamber 7. It is an infrared sensor that detects the food temperature inside. As shown in FIG. 3, the food placing tray 14 includes a food placing portion 15, a side wall portion 16, a frame portion 17 that extends in the horizontal direction and is placed on the rail 13, and a food placing portion. And a heat generation layer 18 corresponding to a heat generation member that generates heat by absorbing microwaves, and is placed on the food placement tray 14 by heat generated by the heat generation layer 18. The food is burnt and cooked.

FIG. 4 schematically shows the electrical configuration of the microwave oven according to the present embodiment. 19 is an external commercial power source, 20 is a power switch, 21 is a rectifier bridge for rectifying an AC voltage, 22 is a choke coil for noise removal, and 23 is a DC power source by smoothing the pulsating current rectified by the rectifier bridge 21. 24 is a switching element made of IGBT, 25 is a flywheel diode connected in parallel between the collector and emitter of the switching element 24, 26 is a resonant capacitor connected in parallel to the flywheel diode 25, and 27 is a high-frequency transformer. is there.

  The high-frequency transformer 27 has a primary winding 28 connected between a connection point between the choke coil 22 and the smoothing capacitor 23 and a connection point between the switching element 24 and the resonance capacitor 26, and the voltage of the primary winding 28. It consists of a secondary winding 29 that boosts and outputs, and a heater winding 31.

  The smoothing capacitor 23, the switching element 24, the flywheel diode 25, the resonant capacitor 26, and the primary winding 28 constitute an inverter circuit that converts a commercial AC power source to a high frequency power source.

  Reference numeral 31 denotes a high voltage capacitor, and 32 denotes a high voltage diode. The high voltage capacitor 31 and the high voltage diode 32 are connected in series to constitute a half-wave voltage doubler rectifier circuit. This half-wave voltage doubler rectifier circuit is connected in parallel to the secondary winding 29 of the high-frequency transformer 27 and supplies the magnetron 8 with a half-wave rectified high voltage to drive the magnetron. 33 is a cathode of the magnetron 8 connected to the heater winding 30, and 34 is an anode of the magnetron 8 connected to the secondary winding 29.

  35 is an oven thermistor that detects the temperature in the heating chamber 7, 36 is an upper heater that radiates and heats from the top surface of the heating chamber 7, and 37 is air in the heating chamber for heating food from the rear surface of the heating chamber 7 by circulating hot air. A back heater for heating, an interior lamp for illuminating the inside of the heating chamber, a current transformer for detecting a current flowing into the magnetron, and a control circuit for generally controlling the operation of the microwave oven 1. The control circuit 40 includes a microcomputer.

  In this configuration, the operation of a cooking course using a food placing tray, for example, a fried egg course will be described. In this cooking course, a course in which the food placing tray 14 is first preheated and then food is placed and cooking is performed will be described.

  First, in step S1, heating conditions are input from the key input unit 6 of the operation unit 5. For example, the temperature of the food placing tray 14 is set to 200 °. Then, only the food placing tray 14 is accommodated in the heating chamber 7 without placing food, and the door 3 is closed. In step S2, it is determined whether or not the start button operation of the key input unit 6 has been performed. If it is determined that the operation has been performed in step S2, the process proceeds to step S3 to start the heating operation. In step S3, the infrared sensor 16 detects the initial temperature of the food placing tray. In step S4, the preheating time T is set according to the initial temperature detected in step S3.

  In step S5, the magnetron 8 is driven at a high output. In step S6, it is determined whether half of the set preheating time T has elapsed. Until the time T / 2 elapses, the high output driving in step S5 is continued. If it is determined in step S6 that the time has elapsed, the process proceeds to step S7, where the output of the magnetron 8 is reduced to a medium output and heating is continued. In step S8, it is determined whether the preheating time T has elapsed. Until this preheating time T elapses, step S7 is continued.

  If it is determined in step S8 that the preheating time T has elapsed, the process proceeds to step S9, heating is stopped, preheating is notified by a buzzer or the like (not shown), and the food is placed on the food placing tray 14 for the user. Encourage you to. In step S10, it is determined whether the door 3 has been opened or closed, that is, whether the door 3 is opened, food is placed on the food placing tray 14, and the door 3 is closed again. In step S11, after the determination in step S10, it is determined whether or not the start button of the key input unit 6 has been operated. If it is determined that the operation has been performed, the process proceeds to step S12, and a cooking program such as a cooking operation, that is, a high output drive of the magnetron 8 for 2 minutes is executed. In step S13, it is determined whether or not the cooking operation in step S12 has been completed. The cooking operation in step S12 continues until it is determined that the step has been completed. If it is determined in step S13 that the cooking operation has been completed, the process proceeds to step S14, the heating operation is stopped, the cooking end notification is given, the user is notified of the end of cooking, and the cooking operation is ended.

  In the above-described steps, steps S3 to S9 indicate a preheating process, and steps S12 to S13 indicate a cooking process.

  Note that the preheating time T set in step S4 is set in consideration of lowering the output of the magnetron 8 on the way.

  With this operation, as shown in FIG. 6, the temperature of the food placing tray 14 rises at the initial stage of heating, but the entire heating layer 18 does not rise uniformly and increases in a state where the temperature rise value is uneven. To do. Thereafter, when a time T / 2 that is half of the set preheating time T has elapsed, the output of the magnetron 8 is reduced to a medium output and heating is continued. At this time, the temperature rise value of the food-loading tray 14 becomes gentle, but heat is transferred from the high temperature portion to the low temperature portion, and the temperature rise in the heat generating layer 18 is substantially reduced. For example, when fried eggs are cooked, as in the past, some of them are baked well, while others can be finished in a half-life state.

It is an external view of the microwave oven which is one Example of this invention. It is AA sectional drawing in FIG. It is an external view of the food mounting tray. It is a control block diagram of the microwave oven of the present invention. It is an operation | movement flowchart of the control circuit for preheating the food mounting tray of this invention, and performing cooking heating after that. It is a figure which shows the relationship between preheating time and the temperature of the magnetron output or the food mounting tray.

Explanation of symbols

7 Heating chamber 8 Magnetron 14 Tray for food placement 18 Heating layer

Claims (1)

A heating chamber that can store food, a magnetron that supplies microwaves to the heating chamber to microwave-heat the food, and a heating member that can be stored in the heating chamber and generates heat by absorbing the microwave A food placing table, and a control unit that controls driving of the magnetron, and the control unit performs a preheating step and a cooking step when baking the food using the food placing table. In the preheating process, the first half drives the magnetron at a high output, and the second half drives the magnetron by reducing the output of the magnetron.