JP2013026170A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a user-friendly induction heating cooker in which the position of a pot can be always detected without being affected by the contamination of a plate or the like.SOLUTION: The induction heating cooker comprises a top plate on which a pot is mounted, a heating coil 5 provided below the top plate, an inverter circuit 304 which supplies a high frequency current to the heating coil 5, a plurality of pot detection coils 310 provided below the top plate, an inverter circuit 309 for pot detection which supplies a high frequency current to the pot detection coils 310, a coil current detection circuit 312 which detects a current flowing through the pot detection coils 310, and a control means 307 for controlling the inverter circuit 304 so as to adjust the power for heating the pot according to the output from the coil current detection circuit 312.

Description

  The present invention relates to an induction heating cooker that efficiently detects misalignment of a pan.

  Conventionally, in this type of induction heating cooker, in order to efficiently heat the pan, a circular mark indicating the position where the pan is placed on the top surface of the top plate is shown.

  However, the top plate on which the pan is placed is only printed on the flat surface of glass or ceramic to indicate the mounting position of the pan, so it is unconscious when putting ingredients in the pan or mixing. There is a problem that the position of the pan shifts.

  Therefore, as shown in Patent Document 1, an inductive coil (heating coil) consisting of an inner coil and an outer coil that are concentrically independent is provided, and an inner coil current detecting means and an outer coil detecting means for detecting a current flowing through each coil. Based on the output from the current detection means, the pan bottom judgment means can judge the material of the pan and the size of the pan, and the position deviation judgment means can determine the position of the pan relative to the inner coil and the outer coil. Can be determined. And there exists what controls the electricity supply with respect to an inner coil and an outer coil according to the magnitude | size and position shift of the judged pan.

  Moreover, as shown in patent document 2, there exists what detects a position shift and a shape of a pan by providing several optical sensors.

JP 2004-127721 A JP 2010-108796 A

  In the above prior art, the induction heating cooker shown in Patent Document 1 confirms how much area the pan occupies in each of the inner coil and the outer coil, and when there is no pan in more than half of the coil, The supply of power to the coil is stopped. For example, when the placement position of the pan is shifted and the pan is in a state less than half of the area of the outer coil, the power to the outer coil is stopped and the pan is heated only by the inner coil. Therefore, even if the cook notices a pan shift during cooking and corrects the pan position, the power supply to the outer coil is stopped, so the current cannot be detected by the outer coil current detection means, so the power to the outer coil cannot be detected. There is a problem that power cannot be supplied.

  In addition, the induction heating cooker shown in Patent Document 2 has a problem that the position and shape of the pan cannot be accurately detected when the light transmission window becomes dirty due to dirt.

  The present invention has been made to solve the above-described problem, and includes a top plate on which a pan is placed, a heating coil provided below the top plate, and an inverter that supplies high-frequency current to the heating coil. A circuit, a plurality of pan detection coils provided below the top plate, a pan detection inverter circuit for supplying a high frequency current to the pan detection coil, and a coil current detection circuit for detecting a current flowing through the pan detection coil And control means for controlling the inverter circuit so as to adjust the electric power for heating the pan in accordance with the output of the coil current detection circuit.

  The induction heating cooker of the present invention can always detect the position of the pan without being affected by dirt on the top plate, and can provide an easy-to-use induction heating cooker.

The perspective view of the state which incorporated the induction heating cooking appliance of one Example in the system kitchen. The perspective view of the induction heating cooking appliance of one Example. The top view of the heating coil of the induction heating cooking appliance of one Example. The block diagram explaining the structure of the induction heating cooking appliance of one Example.

  Hereinafter, an induction heating cooker according to an embodiment of the present invention will be described with reference to FIGS.

  In FIG. 1 and FIG. 2, the top plate 2 is arrange | positioned horizontally at the main body 1 upper surface of the induction heating cooking appliance. The top plate 2 is made of crystallized glass with high heat resistance, and a cooking container such as a magnetic pan such as iron or a non-magnetic pan such as aluminum (not shown) is placed thereon. A top plate frame 3 is provided around the top plate 2, and a sealing material (not shown) is filled between the top plate 2 and the top plate frame 3 so as to be fixed around the top plate 2. Thus, the water overflowing on the top plate 2 has a watertight structure so as not to leak into the main body 1. The top plate frame 3 is fixed to the main body 1. When the main body 1 is installed in the system kitchen 13, the main body 1 is dropped from the upper surface of the system kitchen 13 and incorporated, and the main plate 1 is suspended by the top plate frame 3. Installed.

  In addition, heating coils 5 are disposed in the front side right, left side, and rear center inside the main body 1 below the top plate 2, and a magnetic material such as iron placed on the top plate 2 or aluminum or the like. Induction heating a non-magnetic pot. The front left and right heating coils 5 have a heating output (heating power) of up to 3 kW for cooking that requires a relatively large heating power, such as fried foods and fried foods. The diameter of the heating coil 5 is approximately 200 mm so that it can be heated. Further, the heating coil 5 disposed on the center rear side of the top plate 2 is used for cooking which does not require much work during cooking such as heat insulation, stewed cooking, cooking rice cooking, etc. and has relatively low heating power. It has a heating output (thermal power) of 6 kW.

  On the top surface of the top plate 2 on which the pan is placed, a pan position display unit 4 is displayed so that the pan can be placed at the same position as the heating coil 5 provided below the top plate. The user can efficiently heat the pan by placing the pan in accordance with the pan position display unit 4.

  An upper surface operation unit 12 is provided along the side of the top plate 2 on the near side of the upper surface, and the upper surface operation unit 12 is provided with an upper surface operation key 12a and an upper surface display unit 12b (FIG. 2). The upper surface operation key 12a is provided with a key for turning on / off energization of each heating coil 5, a key for setting heating power, a key for setting an energization timer value, a menu key for setting automatic cooking, and the like. And the upper surface display part 12b displays the energization state of each heating coil 5, and the setting content of a thermal power in an easy-to-understand manner.

  An intake port 8 opened upward is provided on the right side of the rear portion of the main body 1, and a cooling air sucked from the intake port 8 is sucked into the main body 1 by a fan (not shown) provided in the main body 1. It cools by flowing in the control board (not shown), the heating coil 5, etc. which were provided. An exhaust port 9 for exhausting cooling air that has cooled the inside of the main body 1 is provided on the left side of the rear portion of the main body 1.

  A grill heating means 6 is provided on the left side of the front surface of the main body 1. 7 is a door of the grill heating means 6, and a handle 7a is provided. In addition, a tray (not shown) that can be taken in and out is housed inside the grill heating means 6.

  Reference numeral 10 denotes an openable / retractable front operation unit which mainly operates the grill heating means 6 and is provided on the right side of the front surface of the main body 1 so as to be located next to the grill heating means 6 in this embodiment. Further, when the front operation unit 10 is closed, the locking device (not shown) is released by pushing the upper part to the main body 1 side, and the upper part of the front operation unit 10 is provided with a spring and a control device (not shown). )), When it is closed, it is housed in the main body 1 by pushing the upper part toward the main body 1 and held by the locking device. ing. 1 shows a state where the front operation unit 10 is open, and FIG. 2 shows a state where the front operation unit 10 is closed.

  The front operation key 10a of the front operation unit 10 performs operations such as turning on / off the sheathed heater 302 (FIG. 4) of the grill heating means 6, and the contents operated by the front operation key 10a are indicated to the user by the front display unit 10b. Easy to understand. A power off / on switch 11 is provided on the front surface of the main body 1 to turn on / off the main power of the main body 1.

  FIG. 3 is a top view of the heating coil of the induction heating cooker in the present embodiment. As shown in FIG. 3, the heating coil 5 includes an inner heating coil 5a and an outer heating coil 5b. Reference numeral 310 denotes a pan detection coil, which is provided in the heating coil 5 at a plurality of locations. In the present embodiment, the pan detection coils 310 are provided at a total of five locations, one at the center of the heating coil 5 and four between the inner heating coil 5a and the outer heating coil 5b.

  The pan detection coil 310 detects the presence or absence of a pan as a heated object and the material of the pan. Unlike the heating coil 5, the pan detection coil 310 does not need to heat the pan, so that the necessary power source may be an extremely small high-frequency current. Then, a high-frequency magnetic field is generated and a current flowing through the pan detection coil 310 is detected in a magnetically coupled state with the pan to detect whether the pan is placed above the pan detection coil 310, and the material of the pan Is also detected.

  FIG. 4 is a block diagram illustrating a circuit configuration of the induction heating cooker according to the first embodiment. In FIG. 4, 301 is an AC power source, which is a commercial power source that supplies power to the induction heating cooker. Reference numeral 302 denotes a sheathed heater that heats an object to be heated placed inside the grill heating means 6. A heater control circuit 303 controls energization of the sheathed heater 302. An inverter circuit 304 supplies high-frequency power to the heating coil 5 so as to obtain a heating output in accordance with a control signal from a control unit 307 described later. Reference numeral 311 denotes a temperature detector that detects the temperature of the lower surface of the top plate 2 and detects the temperature of the pan that is the object to be heated via the top plate 2. Reference numeral 308 denotes filter means equipped with a filter circuit, which suppresses noise generated from each inverter circuit 304 and prevents noise noise from leaking to the commercial power supply 301. Reference numeral 310 denotes the aforementioned pan detection coil. Reference numeral 309 denotes a pan detection inverter circuit that supplies a high-frequency current to the pan detection coil 310 in accordance with a control signal from the control means 307 described later. Reference numeral 312 denotes a coil current detection circuit which detects a current flowing through the pan detection coil 310. Reference numeral 313 denotes an input current detection circuit that detects a current flowing from the commercial power supply 301. The number of the pan detection coils 310, the coil current detection circuits 312 and the pan detection inverter circuit 309 is provided as necessary.

  A control unit 307 is configured by a microcomputer and outputs a display signal to the front display unit 10b and the upper display unit 12b in accordance with input of an operation signal from the front operation key 10a and the upper operation key 12a. Control signals are also output to the heater control circuit 303 that controls the energization of the sheathed heater 302, the inverter circuit 304 that controls the energization of the heating coil 5, and the pan detection inverter circuit 309 that controls the energization of the pan detection coil 310. Further, according to the detection value from the coil current detection circuit 312, it is determined whether the pan is placed above the pan detection coil 310 and what is the material of the pan.

  The operation of the induction cooking device configured as described above will be described. The pan containing the food is placed on the top plate 2, the upper surface operation unit 12 is operated to set a desired heating power, and the energization start key is operated to start energization. The control means 307 first drives the pan detection inverter circuit 309 to supply power to the pan detection coil 310, and in accordance with the detection value detected by the coil current detection circuit 312, the material of the pan that is to be heated, Alternatively, it is confirmed whether the pan is properly placed on the placement pan position display unit 4.

  Then, after confirming that the pan is properly placed, the frequency and power of the power source applied to the heating coil 5 are determined so as to perform the optimum heating according to the material of the pan, and the inverter circuit 304 is Control and supply electric power to the heating coil 5 to start heating the pan.

  During heating, a slight high frequency current is applied to the pan detection coil 310 to confirm the position information of the pan, and even at one of the four pan detection coils 310 provided between the inner heating coil 5a and the outer heating coil 5b. If it is determined that there is no pan, a notification sound or display informs the cook that the pan has shifted.

  Moreover, only the pan detection coil 310 provided in the center part of the heating coil 5 detects a pan, and the four pan detection coils 310 provided between the inner side heating coil 5a and the outer side heating coil 5b do not detect a pan. There is. In such a case, it is determined that the placed pan has a small diameter, and there is a pan in one of the four pan detection coils 310 provided between the inner heating coil 5a and the outer heating coil 5b during the heating. If it is determined, inform the cook that the pan has shifted. Moreover, when it is detected that there is no pan in all the pan detection coils 310, the control means 307 stops the supply of electric power to the heating coil 5 and notifies the cook.

  Further, during the heating, the pan detection inverter circuit 309 is driven to supply power to the pan detection coil 310 and the detection is continued by the coil current detection circuit 312. Therefore, even if it is determined that there is no pan, Resume heating when placed in the proper location.

  A plurality of installation locations for the pan detection coil 310 may be provided outside the center of the heating coil 5 and the outer periphery of the heating coil 5. In addition, by designing so that a large current can flow through the pan detection coil 310, a high frequency high current may be passed through the pan detection coil 310 that has been determined to have a pan to heat the pan.

  According to the above-described embodiment, the position of the pan can always be detected without being affected by dirt on the top plate, and an easy-to-use induction heating cooker can be provided.

2 Top plate 5 Heating coil 304 Inverter circuit 307 Control means 309 Pot detection inverter circuit 310 Pot detection coil 312 Coil current detection circuit

Claims (1)

  A top plate on which the pan is placed, a heating coil provided below the top plate, an inverter circuit for supplying a high-frequency current to the heating coil, and a plurality of pan detection coils provided below the top plate; , A pan detection inverter circuit for supplying a high frequency current to the pan detection coil, a coil current detection circuit for detecting a current flowing in the pan detection coil, and an electric power for heating the pan in accordance with an output of the coil current detection circuit And an induction heating cooker comprising: control means for controlling the inverter circuit so as to adjust the frequency.