JP4654735B2 - Induction heating device - Google Patents

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 temperature of the top plate is abnormally high, or, or blocked cooling passages, such as air inlet, a cooling fan is not operating inverter structure When the temperature of an electronic component such as a switching element or resonance capacitor that is abnormally high is detected and the energized power to the heating coil is suppressed, the power that is energized to the heating coil is set. The power does not match, and the user has a problem that the power that is actually energized is not known and the usability is deteriorated.

  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.

To achieve the above object, the induction heating apparatus of the present invention includes an insulating plate for placing the object to be heated which has a light transmitting property with part or all, provided under the insulating plate, the object to be heated A heating coil that heats the heating coil, an input power detection means that detects energization power to the heating coil, and a light emitting means that is arranged in the vicinity of the magnetic flux generated by the heating coil and that responds to a signal from the input power detection means the brightness was variable display means for displaying the light of the light emitting means as a figure through the light transmitting portion of the insulating plate, and an output control means for controlling the energization of the heating coil, energization of the heating coil Power setting means for setting power, and the display means 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 a predetermined range to a predetermined range, Within a predetermined time , The luminance of the light emitting means is obtained by a structure for displaying by varying the brightness so that the maximum luminance.

  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.

When the difference between the set power and the power applied to the heating coil is large, the display means determines and displays the luminance according to the power supplied to the heating coil. When the electric power and the electric power supplied to the heating coil coincide with each other or within a predetermined range, the luminance of the light emitting means is greatly changed (for example, light emission at the maximum luminance) within a predetermined time (for example, 2 seconds). Therefore, the user can recognize that the desired power is obtained, and the usability is improved.

  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.

When the difference between the set power and the power applied to the heating coil is large, the display means determines and displays the luminance according to the power supplied to the heating coil. When the electric power and the electric power supplied to the heating coil coincide with each other or within a predetermined range, the luminance of the light emitting means is greatly changed (for example, light emission at the maximum luminance) within a predetermined time (for example, 2 seconds). Therefore, the user can recognize that the desired power is obtained, and the usability is improved.

The first invention, an insulating plate for placing the object to be heated which has a light transmitting property with part or all, provided under the insulating plate, a heating coil for heating the object to be heated, the heating coil An input power detection means for detecting the power supplied to the heater and a magnetic flux generated by the heating coil are arranged in the vicinity of the magnetic flux, and the brightness of the light emission means is varied according to a signal from the input power detection means. Display means for displaying light as a figure through a light-transmitting portion of the insulating plate, output control means for controlling energization to the heating coil, power setting means for setting energization power to the heating coil, The display means includes the light emitting means within a predetermined time from a time point when the difference between the set power and the power by the input power detecting means shifts from a state not within the predetermined range to a predetermined range. Is the maximum brightness It becomes as those configured to display by varying the brightness. 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 way as the user can visually feel the feeling of firepower 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 the 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 the size of the power circuit for driving the light source Can be planned.

When the difference between the set power and the power applied to the heating coil is large, the display means determines and displays the luminance according to the power supplied to the heating coil. When the electric power and the electric power supplied to the heating coil coincide with each other or within a predetermined range, the luminance of the light emitting means is greatly changed (for example, light emission at the maximum luminance) within a predetermined time (for example, 2 seconds). Therefore, the user can recognize that the desired power is obtained, and the usability is improved.

According to a second aspect of the present invention, in the first aspect of the invention, the first aspect further includes abnormality detection means for detecting that the temperature of the insulating plate and the temperature of each part constituting the output control means are equal to or higher than a predetermined value. When the energization is stopped or the output power is suppressed by the output of the abnormality detection means, the brightness of the light emission means determined according to the set power and the brightness of the light emission means determined according to the power of the input power detection means When the display means has a difference of more than a predetermined value , the display means alternately displays the brightness of the light emitting means, so that the temperature of the insulating plate and the temperature of each part constituting the output control means can be 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.

A third invention is, in particular, in the first or second aspect, the display unit, when changing the Brightness, by gradually increasing or decreasing constitutes the output of the light emission means can recognize an abnormal state At the same time, the luminance of the light emitting means does not change greatly during normal use, and the display is not flashy, which is not cumbersome and improves usability.

  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 the present embodiment, the heating coil 2 is formed by winding a litz copper wire, which is a bundle of 50 strands having a diameter of about 0.3 mm, in a donut shape for 25 turns, and has 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 performing, the user by abnormalities of what Laka, recognizes that it is impossible to obtain the desired power, further, it is possible to 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), etc. 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

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 (3)

Detecting an insulating plate for placing the object to be heated to a part or the whole was a light transmitting property, provided under the insulating plate, a heating coil for heating the object to be heated, the energization power to the heating coil And an input power detection means that is arranged in the vicinity of the magnetic flux generated by the heating coil , varies the brightness of the light emission means in accordance with a signal from the input power detection means, and transmits the light of the light emission means to the insulating plate. display means for displaying a figure through the light transmitting portion, and an output control means for controlling the energization of the heating coil, and a power setting means for setting the energization power to the heating coil, the display means Means that the luminance of the light emitting means is the maximum luminance within a predetermined time from the time when the difference between the set power and the power by the input power detecting means is not within the predetermined range. bright in such a way that Induction heating device for a variable and displays constituting. 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 When 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 display means alternately displays the light emission. The induction heating apparatus according to claim 1, wherein the display is performed according to the brightness of the means. Display means, in the case of changing the Brightness, induction heating apparatus according to claim 1 or 2 was gradually increased or decreased constitutes the output of the light emission means.