JP2006286499A - Induction heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To clarify a mounting place of a heating object while suppressing increase of the number of components and component volumes, and to make display of a current-carrying power state. <P>SOLUTION: The display of the mounting place of the heating object and the current-carrying power to a heating coil 2 are detected by an input power detection means 7. A display means 4 makes a light emitting means 6 emit light with luminance according to the input power by the input power detection means 7, and thereby indicates the mounting place of the heating object or which is the mounting place in process of carrying a current thereto when there are a plurality of mounting places. A user recognizes the current-carrying power state to the heating coil 2 by the indication. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an induction heating apparatus used in general homes, restaurants, offices, factories and the like.

  A conventional induction heating apparatus will be described by taking an induction heating cooker as an example. By using a multi-stage light emitting means having multi-stage light emission luminance and irradiating the liquid crystal display element with light emission luminance corresponding to the input power, it is possible to easily identify the thermal power during heating visually. It is disclosed (for example, see Patent Document 1).

  In addition, a light guide is arranged around the heating coil, light from the light source is emitted through the light guide, and the pan is formed with the light depending on whether the heating coil is energized. The thing which makes it easy to understand the mounting place etc. of a to-be-heated body, such as, is disclosed (for example, refer patent document 2).

In addition, an operation unit for setting the level of heating power is provided, and a light emitter is arranged around the entire circumference of the heating coil or a part of the periphery of the heating coil. Has been disclosed in which the level of heating power, the setting state, the heating state, the heating power, and the like during heating is recognized more easily (see, for example, Patent Document 3).
JP-A-7-94267 JP 2001-326064 A JP 2003-234167 A

  However, when the liquid crystal display element is irradiated with the light emission luminance corresponding to the input power by using the multi-stage light emitting means having the multi-level light emission luminance in the conventional configuration, the liquid crystal display element is irradiated according to the power. Since the emitted light intensity changes, when the input power is small, the visibility of the liquid crystal display element deteriorates and the usability deteriorates. Further, if the luminance when the input power is small is increased in order to ensure visibility, the difference from the case where the input power is large becomes small, and the input power becomes difficult to recognize. Furthermore, when the place where the liquid crystal display element is disposed is provided at a position away from the heating coil, it is difficult to recognize that heating is being performed. In addition, a light source, a light guide unit, and a drive circuit, which are light-emitting means constituting the multi-stage light-emitting means for irradiating the liquid crystal display element, are required, and the drive power supply circuit for the light source is increased.

  In addition, the light guide disposed around the heating coil is easy to understand the place where the heated object such as a pan is placed, and it is easy to recognize that it is being heated. There was a problem that it was impossible to recognize the size of the flame and get a feeling of firepower.

  In addition, those that change the emission color or luminance of the light emitter in multiple steps according to the set heating power level can recognize the thermal feeling and setting state, but depending on the material, for example, the difference in the material of the pot, If excessive voltage may be applied to the switching elements and resonant capacitors that make up the inverter, and excessive voltage is applied to the switching elements and resonant capacitors that make up the inverter with a pan that is smaller than the diameter of the heating coil, for example, If there is something, or if you do not want to heat it, such as a spoon or knife, the heated object that can not be heated with the power set by or abnormal, for example, if the pan is not placed, there is less food in the pan If the top plate temperature is abnormally high, or if the cooling passage such as the air intake is blocked or the cooling fan does not work, When the temperature of electronic components such as switching elements and resonant capacitors that are formed is abnormally high, and the power applied to the heating coil is suppressed, the power applied to the heating coil is set. Therefore, the user has a problem that the user does not know the power that is actually energized and the usability becomes worse.

  SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and by placing the object to be heated on the display of the placement location and the display of the energization state of the heating coil together with an integrally configured display means, the object to be heated is mounted. When there are multiple installation locations or multiple installation locations, it indicates which installation location is being energized, and the user can recognize the state of the energized power to the heating coil, making induction heating more convenient to use. An object is to provide an apparatus.

  In order to achieve the above object, an induction heating apparatus according to the present invention is provided with an insulating plate in which a part or all of the object to be heated is made light transmissive, and provided below the insulating plate to heat the object to be heated. A heating coil, a display means arranged in the vicinity of the magnetic flux generated by the heating coil and displaying the light of the light emitting means as a figure through the light-transmitting portion of the insulating plate, and an output for controlling the energization of the heating coil The control means and the input power detection means for detecting the energization power to the heating coil are provided, and the light emission means is configured to display the variable luminance based on the signal from the input power detection means.

  As a result, the place where the object to be heated is placed is clarified, and the user can recognize the state of the energized power to the heating coil.

  The induction heating device of the present invention makes it possible to clarify the place where the object to be heated is placed, and to bring about the same effect as visually obtaining a feeling of thermal power depending on the size of the flame of the gas burner. In addition, the number of wiring for transmitting display signals, the number of light emitting means as light sources, the number of light guide members for making light from the light sources into a figure of a desired shape, etc., and a power supply circuit for driving the light sources The cost can be reduced by reducing the size of the device.

  A first invention includes an insulating plate in which part or all of a body to be heated is made light-transmitting, a heating coil that is provided below the insulating plate and that heats the body to be heated, and the heating coil Display means for displaying the light of the light emitting means as a figure through the light-transmitting portion of the insulating plate, output control means for controlling energization to the heating coil, and Input power detecting means for detecting the energization power to the heating coil, and the light emitting means is configured to display with variable luminance based on a signal from the input power detecting means. As a result, the heating coil is energized by the output control means to inductively heat the object to be heated placed on the insulating plate, and the figure formed by the light generated from the light emitting means is made transparent to the insulating plate. The heating coil is energized to the user, and the heated part near the magnetic flux generated by the heating coil, that is, the position where the heated object is to be placed Can be recognized accurately. Furthermore, since the brightness of the figure formed by the light generated from the light emitting means displayed through the light-transmitting part of the insulating plate changes according to the energization power of the heating coil, the flame of the gas burner The user can obtain a feeling of firepower according to the brightness of the figure in the same manner as the feeling of firepower is visually obtained according to the size. At this time, a part or all of the figure formed by the light generated from the light emitting means is displayed by sharing the position where the object to be heated is placed and the energized power state of the heating coil. Reduce the number of wires for signal transmission, the number of light emitting means to be a light source, the number of light guide members to make the light from the light source into a figure of the desired shape, etc., and downsizing the power circuit for driving the light source Can be planned.

  In particular, the second invention includes, in the first invention, power setting means for setting the energization power to the heating coil, and the difference between the set power and the power by the input power detection means is not within a predetermined range. When the brightness of the light-emitting means is changed and displayed within a predetermined time from the time when it shifts to a predetermined range, when the difference between the set power and the power applied to the heating coil is large. The light emitting means determines and displays the luminance according to the power applied to the heating coil, and the set power and the power supplied to the heating coil match or fall within a predetermined range. In this case, the light emitting means greatly changes the luminance (for example, light emission at the maximum luminance) within a predetermined time (for example, for 2 seconds), so that the user can recognize that the desired power is obtained and the usability is improved.

  The third invention, in particular, in the first or second invention, further comprises an abnormality detection means for detecting that the temperature of the insulating plate and the temperature of each part constituting the output control means is equal to or higher than a predetermined value. When the control means stops energization or suppresses the output power by the output of the abnormality detection means, the light emission determined according to the brightness of the light emission means determined according to the set power and the power of the input power detection means When there is a difference between the brightness of the means and a predetermined value or more, the brightness of each light emitting means is displayed alternately so that the temperature of the insulating plate and the temperature of each part constituting the output control means are changed. It is high, and it is possible to recognize both the energized power state to the heating coil and the set power when the energized power to the heating coil is stopped or suppressed. Furthermore, when a heated object that is dangerous when heated, such as a spoon or knife, is detected, or when a heated object that cannot be heated with the power set according to the material and shape is heated, Both of the set power can be recognized.

  In a fourth aspect of the invention, in particular, in any one of the first to third aspects of the invention, when the light emitting means changes the luminance, size, shape, or emission color, the luminance, size, shape, or the light emitting means, or By adopting a configuration that gradually increases or decreases the emission color, abnormal states can be recognized, and the luminance of the light emitting means does not change greatly during normal use, so the display does not become flashy, so it is not cumbersome and improves usability. .

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, an adjustment unit that adjusts the luminance of the light emitting unit and a storage unit that stores the luminance set by the adjustment unit are provided. The storage means for storing the brightness is a nonvolatile storage element (for example, EEPROM), and the brightness value corresponding to the set input level is stored by a key operation by the setting means. As a result, the brightness of the light emitting means can be adjusted, so that the light can be emitted with an appropriate brightness according to the brightness of the lighting of the room in use, and the adjustment according to the convenience of the user is possible. . Furthermore, since it can adjust according to the light transmittance of an insulating plate, it can adjust at the time of shipment according to the difference in the light transmittance of the insulating plate by the difference between models, without impairing design property.

  According to a sixth aspect of the invention, in particular, in any one of the first to fifth aspects, the size or shape of the figure can be changed according to the display of the portion heated by the heating coil and the output of the input power detection stage. With this configuration, the user can easily check the place where the heated body is placed while energizing the heating coil and heating the heated body, and further recognize the state of the energized power to the heating coil. can do. At this time, since the shape or size of the graphic displayed by the display means is different depending on the energization power of the heating coil, the user is as in the case where the size of the flame of the gas burner changes according to the heating power. Can get a sense of firepower.

  According to a seventh invention, in any one of the first to fifth inventions, the emission color of the light emitting means is varied in accordance with the display of the portion heated by the heating coil and the output of the input power detection stage. By adopting a switching configuration, the user can easily confirm the placement location of the heated body while the heated body is heated by energizing the heating coil, and further recognize the state of the energized power to the heating coil. can do. At this time, since the color of the graphic displayed by the display means is different according to the energization power to the heating coil, it is possible to identify different states of the energization power. In addition, since the figures to be displayed are the same, it is not necessary to increase the number of parts such as the light emitting means constituting the display means, the light source thereof, and the light guide member forming the figure, and the size of the induction heating apparatus is increased. High cost can be suppressed.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking an induction heating cooker as an example. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a top view, a schematic cross-sectional view, and a block diagram showing the configuration of the induction heating apparatus according to the first embodiment of the present invention. As shown in FIG. 1, an output control means for controlling energization to the heating coil 2 and the heating coil 2 and the insulating plate 1 made of crystallized glass having a thickness of about 4 mm provided above the heating coil 2. 5 is formed in the vicinity of the magnetic flux generated by the heating coil 2 below the insulating plate 1 by the display means 4 having the light emitting means 6 so that the user can know the position of the heating coil 2. Displayed via the board 1.

  In this embodiment, the heating coil 2 is formed by winding 50 litz copper wires each having a diameter of about 0.3 mm in a donut shape for 25 turns and having an outer diameter of about 180 mm and an inner diameter of about 50 mm. The shape is about 3 mm thick.

  The light emitting means 6 includes a plurality of LEDs serving as the light source and a light guide for forming the light emitted by the LEDs into a desired figure (in this embodiment, an annular shape whose inner diameter is larger than the outer diameter of the heating coil 2). It is made of a photo resin and is provided in the vicinity where induction heating is possible by the magnetic flux generated by the heating coil 2, and the plurality of LEDs are electrically connected to form a series circuit. Therefore, at least two wiring lead wires for transmitting the driving signal to the light emitting means 6 are sufficient.

  In this embodiment, the output control means 5 is realized by a microcomputer (hereinafter referred to as a microcomputer), and the display means 4 has a drive frequency of the light emitting means 6 of about 100 Hz and a drive time by a PWM (pulse width modulation) function of the microcomputer. The ratio can be varied in 256 steps, and by setting the driving time ratio of the light emitting means 6 to 100%, light can be emitted with the maximum luminance.

  Further, a thermistor 3 a that is a temperature detection element is disposed on the back surface of the insulating plate 1 near the center of the heating coil 2, and the temperature detecting means 3 detects the temperature of the insulating plate 1.

  The input power detection means 7 detects input power, and in this embodiment, the voltage of the commercial power source to be connected, a switching element (not shown) constituting the output control means 5 and a smoothing circuit (see FIG. The input power is detected by detecting an input current to an inverter circuit (not shown) including (not shown). The output control means 5 performs feedback control so that the power detected by the input power detection means 7 becomes the power corresponding to the power level set and input by the setting means (power setting means) 8.

  The setting means 8 inputs a power setting level for energizing the heating coil 2 by the output control means 5, and is an on / off key switch for starting or stopping heating, and an up key switch and a down key for increasing or decreasing the power setting level for energization. Consists of switches.

  About the induction heating cooking appliance comprised as mentioned above, the operation | movement is demonstrated. When the heating on / off key switch of the setting unit 8 is pressed, the heating set power level is set to 1000 W and is input to the output control unit 5. The output control unit 5 starts energization of the heating coil 2 and the input power detection unit. The feedback control is performed so that the power detected by 7 becomes 1000 W. The output control means 5 starts driving current to the heating coil 2 and then reaches the set power of 1000 W until the power is gradually increased so that the drive frequency or drive time of the switching elements constituting the output control means 5 is increased. Change the ratio. In addition, when the output control means 5 starts energizing the heating coil 2, the display means 4 shows the portion heated by the heating coil 2 in a bright annular shape by the light emitted by the light emitting means 6, and the user is able to cover the object such as a pot. It is possible to easily identify the place where the heating body (not shown) is placed. At this time, the display means 4 changes the drive time ratio by PWM in accordance with the power detected by the input power detection means 7 for the luminance of the light emitted from the light emitting means 6. FIG. 2 shows the drive time ratio of the input power and the display means 4 by PWM. As shown in FIG. 2, the light emission luminance of the light emitting means 6 becomes a luminance with a time drive ratio of 32% immediately after the start of heating, and is 60% when the power detected by the input power detection means 7 is 1000 W. The brightness is gradually increased until the power reaches 1000 W immediately after the start of heating. Further, when the heating on / off key switch is pressed during heating and the heating coil 2 is de-energized, the display unit 4 stops driving the light emitting unit 6.

  FIG. 3 is a timing chart showing the luminance from the start of heating until reaching the set power. As shown in FIG. 3, the display unit 4 sets the driving time ratio of the light emitting unit 6 to 100% for 2 seconds from the time when the power detected by the input power detection unit 7 reaches 1000 W. Part 9 of the luminance change process is a state in which the light emitting means 6 emits light at the maximum luminance. In this way, when the set power is reached, the brightness is greatly changed, thereby allowing the user to recognize that the set power has been reached and improving the usability of the user.

  FIG. 4 is a timing chart showing the luminance when the set power and the input power do not match. When the object to be heated is induction-heated by energizing the heating coil 2, the heat of the object to be heated is transmitted to the thermistor 3a via the insulating plate 1, whereby the temperature detecting means 3 controls the temperature of the insulating plate 1. Detect. When the temperature of the insulating plate 1 is about 200 degrees by an abnormality detection means (not shown) while the heating coil 2 is energized with 2000 W of power, the output control means 5 sets the energization power to 1000 W. Further, when the temperature of the insulating plate 1 reaches about 250 degrees, energization to the heating coil 2 is stopped. In this case, as shown in FIG. 4, the display means 4 displays the light emitting means 6 with the brightness at the input power of 1000 W detected by the input power detection means 7 in the part 11 of the luminance change process, When the light emission means 6 is displayed with the luminance corresponding to the electric power set and input by the setting means 8 in the part 10 of the luminance change process, and when each luminance is changed, a part of the luminance change process is displayed. 12, the brightness is changed little by little. In this way, display with brightness according to the input power by the input power detection means 7 and display with brightness at the power level set and input by the setting means 8 are alternately performed, and the change to each brightness is little by little. By doing so, the user can recognize that the desired power cannot be obtained due to some abnormality, and can recognize the actual power. In addition, the luminance change is gradually increased or decreased step by step in order to prevent visual glare from alternately displaying different luminances. In addition, what is necessary is just to determine arbitrarily the step of this staircase in the category which does not produce inconvenience.

  In addition, by displaying the figure formed by the light generated from the light emitting means 6 in common with the position where the object to be heated is placed and the state of the energized power to the heating coil 2, the display signal is transmitted. The number of wirings (in this embodiment, the minimum of two), the number of LEDs included in the light emitting means 6 serving as the light source, and the number of light guide members for forming the light from the LEDs serving as the light source into a desired shape The power supply circuit for driving the light source can be reduced in size.

  In the present embodiment, the display of the portion heated by the heating coil 2 and the display of the power detected by the input power detection means 7 are shared, and the difference between lighting and blinking is provided for display. However, there is a difference in the light emission luminance of the light emitting means 6, or the emission color is changed, or the figure generated by the light emitting means 6 is different in size and shape (for example, depending on the energization power of the heating coil 2). When the power is low, the front half of the figure in this embodiment is lit, and when the power is high, the back half is lit and displayed in an annular shape). It goes without saying that the same effect can be obtained by adjusting the difference within a possible category.

  In addition, it has a storage means for storing the brightness, is constituted by a non-volatile storage element (for example, EEPROM), and is operated by a key operation (for example, an up key down key for adjusting power without providing a dedicated key by the setting means 8) The current luminance may be adjusted while being displayed in real time, and the luminance value may be stored when a desired luminance corresponding to the set input level is obtained. As a result, the luminance of the light emitting means can be adjusted, so that light can be emitted with an appropriate luminance according to the brightness of the lighting in the room in use.

  Further, in this embodiment, the induction heating device of a single heating unit is described. However, if the induction heating device has a plurality of heating units and can individually heat different objects to be heated, each heating coil It goes without saying that by providing each light emitting means in the vicinity of, it becomes clear which heating coil is energized and which heating coil is energized, which improves usability.

  The induction heating device according to the present invention makes it possible to clarify the range where induction heating can be performed on the object to be heated or the mounting position of the object to be heated, and to recognize the state of the energized power to the heating coil. Because it is possible to suppress the increase in the number or volume, it can also be applied to a desktop type IH cooker using induction heating, or a combined type electric heating cooker that combines multiple induction heating units with a fish roaster or an electric heater. Is possible.

Schematic diagram and block diagram of induction heating apparatus in Embodiment 1 of the present invention The figure which shows the drive time ratio of the input electric power or setting electric power of the induction heating apparatus in Embodiment 1 of this invention, and a light emission means Timing chart showing the luminance from the start of heating of the induction heating device to the set power in Embodiment 1 of the present invention Timing chart showing the luminance when the set power and the input power of the induction heating device in Embodiment 1 of the present invention do not match

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulation board 2 Heating coil 3 Temperature detection means 4 Display means 5 Output control means 6 Light emission means 7 Input power detection means 8 Setting means (power setting means)

Claims (7)

A part or all of the insulating plate on which the object to be heated is placed is made light transmissive, a heating coil provided below the insulating plate for heating the object to be heated, and a magnetic flux generated by the heating coil Display means arranged in the vicinity and displaying the light of the light emitting means as a figure through the light-transmitting portion of the insulating plate, output control means for controlling energization to the heating coil, and energization power to the heating coil The induction heating apparatus is configured to display the display unit by varying the luminance based on a signal from the input power detection unit. A power setting means for setting the energization power to the heating coil is provided, and a predetermined time from the time when the difference between the set power and the power by the input power detection means shifts from a state not within the predetermined range to a predetermined range. The induction heating apparatus according to claim 1, wherein the brightness of the light emitting means is varied and displayed. It comprises an abnormality detection means for detecting that the temperature of the insulating plate and the temperature of each part constituting the output control means is equal to or higher than a predetermined value, and the output control means stops energization or output power by the output of the abnormality detection means If there is a difference between the brightness of the light emitting means according to the set power and the brightness of the light emitting means according to the power detected by the input power detecting means, the brightness of the light emitting means alternately. The induction heating device according to claim 1, wherein the induction heating device is configured to display by: The induction heating apparatus according to any one of claims 1 to 3, wherein the light emitting means is configured to gradually increase or decrease the output of the light emitting means when the luminance, size, shape, or emission color is changed. The induction heating apparatus according to any one of claims 1 to 4, further comprising: an adjusting unit that adjusts the luminance, size, shape, or emission color of the light emitting unit; and a storage unit that stores the luminance set by the adjusting unit. The induction heating apparatus according to any one of claims 1 to 5, wherein the light emitting means is configured to display the figure with a variable size or shape. The induction heating apparatus according to any one of claims 1 to 5, wherein the light emitting means is configured to display the light emission color in a variable manner.