JP2005044646A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker in which suppression of power consumption of the whole constituting circuit and noise reduction of an equipment are carried out. <P>SOLUTION: This cooker is provided with a power switch 12 which is installed on the way of power supply path and which divides a heater coil 14 and the power supply, a series connection body of a relay 21 and a capacitor 23 installed between the power supply path of power supply side than the power switch 12, an operation means 19 to operate heating setting, and a control means 16 to control the action of the heater coil 14 based on signals from the operation means 19. The relay 21 opens or closes by directly detecting driving signals from the operation means 19 without passing through the control means 16. By means of this, power consumption of the capacitor 23 to use for high frequency noise suppression at the relay 21 as for the power consumption of all the circuit except the high frequency noise suppression circuit of the power switch 12 can be suppressed, and the noise reduction of the equipment can be carried out. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heating cooker that has a high-frequency noise source such as an inverter and requires a filtering circuit that leaks from a power line to the outside of the device.

Conventionally, as this kind of heating cooker, power is supplied to the high frequency power source necessary for heating immediately before performing the heating operation, and the power consumption of the device is suppressed by not supplying power to the high frequency power source when heating is not performed. What can be done is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-260540

  However, in the conventional configuration, although consideration is given to the high frequency power source, power is consumed in the DC power source and the electronic control circuit, and although not shown, the high frequency noise connected in parallel to the commercial AC power source Even the suppression capacitor consumed power.

  An object of the present invention is to provide a cooking device that suppresses power consumption of the entire constituent circuit including reduction of power consumption of a capacitor for suppressing high-frequency noise, and reduces noise of the device. It is.

  In order to achieve the above object, a heating cooker according to the present invention is provided in the middle of a power supply path between a heating switch and a first switch for dividing the power source, and between the power supply path on the power source side from the first switch. The second switch and the capacitor connected in series, the operating means for operating the heating setting of the heating means, and the control means for controlling the operation of the heating means based on a signal from the operating means, The switch opens and closes by directly detecting the drive signal from the operation means without going through the control means.

  As a result, the power consumption of all circuits except the high-frequency noise suppression circuit can be suppressed by the first switch, the power consumption of the capacitor for suppressing the high-frequency noise can be suppressed by the second switch, and noise from the device can be supplied by the power supply. Propagation from the path to the outside can be prevented, and the noise of the device can be reduced.

  As described above, according to the heating cooker of the present invention, it is possible to suppress the power consumption of the entire constituent circuit including the power consumption reduction of the noise suppressing capacitor and reduce the noise of the device.

  The invention according to claim 1 includes: a heating unit; a power supply path for supplying power to the heating unit; a first switch provided in the middle of the power supply path; The second switch and the capacitor connected in series between the power supply paths on the power source side, the operating means for operating the heating setting of the heating means, and the operation of the heating means based on the signal from the operating means Control means, and the second switch is a heating cooker that opens and closes by directly detecting the drive signal from the operation means without going through the control means, so that the first switch has a high frequency. The power consumption of all the circuits except the noise suppression circuit can be suppressed by the second switch, and the noise from the equipment can be propagated from the power supply path to the outside. Prevention, it is possible to perform noise reduction of the apparatus.

  According to a second aspect of the present invention, there is provided an opening / closing detecting means for detecting opening / closing of the second switch, and the operating means has a contact point of the second switch opened by the opening / closing detecting means while driving the heating means. When the heating cooker according to claim 1 is stopped, the second switch is opened during the heating operation in which the high frequency noise is expected to be increased. When the suppression capacitor is disconnected, the high frequency noise leaking from the power supply path to the commercial AC power supply can be reduced by stopping the heating operation.

  According to a third aspect of the present invention, there is provided storage means for holding information regardless of whether power is supplied or not, and the storage means is configured so that the operation means opens or closes the second switch from open to closed or from closed to open. The cooking according to claim 1 or 2, wherein a power phase when changing is stored, and the operating means switches a plurality of types of power phases when changing the open / close state of the second switch based on information from the storage means. By using this device, the voltage at both ends when the second switch is open or closed can be reduced on average regardless of whether or not power is supplied to the control means, and the reliability of the switch contact welding can be improved. . In addition, the second switch has a plurality of power supply phase timings during opening and closing operations, and these are periodically driven each time they are opened or closed, reducing the inrush current and arc to the desired level on average. it can. Since the previous power phase timing is stored in the sequential storage means, even if the power is not supplied to the control means due to the opening of the first switch or a power failure in the middle, the periodic driving of the power phase is performed next time. This is also continued when the second switch is driven.

  The invention according to claim 4 is the heating cooker according to any one of claims 1 to 3, wherein the second switch is opened or closed according to the energization state of the heating means. During the heating operation, the second switch is closed and a capacitor for suppressing high-frequency noise is connected to reduce high-frequency noise leaking from the power supply path to the commercial AC power supply. Standby power can be saved by disconnecting the capacitor for suppressing high-frequency noise. Moreover, the power consumption required for driving the second switch can be saved by reducing the chance of closing the second switch.

  The invention according to claim 5 is the heating cooker according to any one of claims 1 to 4, wherein the second switch is opened from the closed state after the first switch is opened from the closed state. As a result, the high-frequency noise suppression capacitor is connected between the power supply paths unless the first switch is opened, so that the noise reduction action by the high-frequency noise suppression capacitor can be stably obtained, and the first If the switch is opened, the power supply is cut off so that no noise is generated. Thereafter, the second switch is opened as appropriate, thereby eliminating the standby power generated by the capacitor for suppressing high frequency noise. it can.

  The invention according to claim 6 is the heating cooker according to any one of claims 1 to 5, wherein the second switch is closed from open to closed after the first switch is closed from open. Thus, after both the first and second switches are open, it is possible to prevent standby power from being generated by the high-frequency noise suppressing capacitor unless the first switch is closed.

  The invention according to claim 7 is the heating cooker according to any one of claims 1 to 6, wherein a discharge resistor is connected to both ends of the capacitor, whereby the first switch is open and the second When the switch is closed and the input terminal is disconnected from the commercial AC power supply, the charge stored in the capacitor for high frequency noise suppression can be discharged, thus preventing electric shock from touching the input terminal. In addition, it is possible to prevent an electric shock by touching the substrate during repair work such as substrate replacement.

  Embodiments of the present invention will be described below with reference to the drawings.

  In this embodiment, an induction heating cooker having an induction heating coil for heating a heated pan or the like with a high-frequency magnetic field is shown as a heating cooker.

  As shown in the figure, the commercial AC power supply 11 supplies power to a heating coil 14 that is a heating means via input terminals 10a and 10b that are power supply paths. The heating coil 14 has one or a plurality. The input terminal 10a is connected to the power switch 12 and the power phase detection circuit 17 which are first switches that can be easily operated by the user via the filter circuit 20, and a commercial AC is connected to the load side contact of the power switch 12 A high frequency power source 13 that converts the power source 11 into a direct current to generate a high frequency power source, a direct current power source 15 constituted by an insulating transformer, and a power switch open / close detection circuit 18 are connected. A high frequency power supply 13 and a DC power supply 15 are connected to the input terminal 10 b via a filter circuit 20, and a commercial AC power supply 11 is supplied to the high frequency power supply 13 and the DC power supply 15 via a filter circuit 20 and a power switch 12. It is the composition which becomes. The power switch 12 is provided in the middle of the power supply path, and separates the heating coil 14 and the commercial AC power supply 11.

  Further, between the power supply path 12 and the power supply path on the commercial AC power supply 11 side, a series connection body of the contact of the relay 21 which is the second switch and the capacitor 23 for suppressing high frequency noise is connected. Further, the discharge resistor 24 is connected in parallel to the capacitor 23. Moreover, the relay opening / closing detection means 25 of the relay 21 and the non-volatile storage means 26 which memorize | stores the power supply phase when changing the opening / closing state of the relay 21 are provided. That is, the storage means 26 holds information regardless of whether or not power is supplied, and stores the power phase when the relay 21 that is the second switch is changed from open to closed or from open to closed. To do.

  Further, a DC power supply 15 is connected to the load side contact of the power switch 12, and an operation means 19 for operating the heating setting of the heating coil 14 and a control means for controlling the operation of the heating coil 14 based on a signal from the operation means 19. 16 receives power supply from the DC power supply 15. The operation means 19 receives signals from the power phase detection circuit 17, the power switch open / close detection means 18 and the relay open / close detection means 25, and outputs a signal to the relay 21 in accordance with the signal contents. That is, the relay 21 opens and closes by directly detecting the drive signal from the operation means 19 without using the control means 16. The operation means 19 inputs / outputs signals to / from the storage means 26 and switches a plurality of types of power supply phases when changing the open / close state of the relay 21 based on information from the storage means 26. On the other hand, the control means 16 outputs a signal to the high frequency power supply 13 and a fan motor (not shown) for cooling the high frequency power supply 13 and the heating coil 14 as well as the heating coil 14 in accordance with a signal from the operation means 19. .

  Next, the operation | movement is demonstrated about the heating cooker of a present Example.

  Even if the commercial AC power supply 11 is connected to the input terminals 10a and 10b, the DC power supply 15, the control means 16 and the operation means 19 are not supplied with power. By closing the power switch 12, power is supplied to the DC power supply 15, and the control means 16 and the operation means 19 start operating with an output of about 5 V from the DC power supply 15. When the operation starts, the operation means 19 communicates with the control means 16 and controls the operation of the subsequent devices based on the input signals from the power switch open / close detection means 18 and the relay open / close detection means 25.

  When heating start is selected by operating a heating switch (not shown) built in the operating means 19, the operating means 19 inputs signals from the power phase detection circuit 17 and the power switch open / close detection circuit 18, and the power switch 12 In the closed state, a signal is output to the relay 21 and the relay 21 is closed. The drive signal of the relay 21 is directly transmitted to the relay 21 without passing through the control means 16 so that the relay 21 is driven. The operation means 19 detects the open state of the relay 21 from the relay open / close detection means 25, and then transmits a close state signal of the relay 21 and a heating start signal to the control means 16. After receiving the signal, the control means 16 starts supplying a high-frequency current to the heating coil 14, that is, starts a heating operation. When the heating operation is started, the control means 16 operates the fan motor to cool the high frequency power supply 13 and the heating coil 14.

  The relay 21 is closed after the power switch 12 is closed and before the above-described heating operation, and suppresses noise propagating from the high-frequency power source by the filter circuit 20 formed by the capacitor 23 and the common mode coil 22. To do. The power supply phase when the relay 21 is closed is set in advance in a plurality of stages (eight stages here) in the operation means 19, and every time the relay 21 is closed from open as shown in FIG. Periodic switching is performed in the order of e → b → f → c → g → d → h. The storage means 26 sequentially stores the latest power supply phase timing (any one of a to h in FIG. 2) when the relay 21 is closed, and power is not supplied to the operation means 19 when the power switch 12 is opened. Even if it becomes a state, the above-described periodic switching operation of the power supply phase continues. For example, even if the operation means 19 turns off the power when the power phase f is reached, the next relay 21 is closed from the timing c. If the storage means 26 does not hold the phase, the operating means 19 is initialized, so that the timing returns to a every time the power is turned off, and the power supply phase cannot be switched periodically.

  Next, when the power switch 12 is opened from the closed state, the power supply to the high frequency power supply 13 is stopped, and the half wave of the commercial AC power supply 11 is supplied to the DC power supply 15 via the relay 21. The operating means 19 recognizes the opening of the power switch 12 by the input from the power switch open / close detecting means 18, and after the power switch 12 is opened, the relay 21 is opened from the closed state, and after the relay 21 is opened, the relay is opened. The power supply to the capacitor 23, the discharge resistor 24, and the DC power supply 15 is stopped, and the power consumption when the power switch 12 is opened is suppressed.

  Here, the power supply phase when the relay 21 is opened from the closed state is the same as the above-described power supply phase control when the relay 21 is opened to closed, a → e → b → f → c → g → d shown in FIG. → The switching is performed periodically in the order of h, and the storage means 26 also stores the latest power supply phase timing (any one of a to h in FIG. 2) sequentially when the relay 21 is opened, Even if the power switch 12 is opened, the relay 21 is opened, or a power failure occurs, the operation means 19 is not supplied with power, so that the periodic switching operation of the power phase continues.

  In addition, when the relay 21 is opened during the heating operation and a signal is input from the relay open / close detection unit 25 to the operation unit 19, the operation unit 19 transmits a heating operation stop signal to the control unit 16 and stops the heating operation. While the operation means 19 detects the opening of the relay 21 from the relay open / close detection means 25, the heating operation by the heating switch cannot be performed.

  As described above, according to the present embodiment, the power switch 12 as the first switch is provided in the middle of the power supply path for supplying the power current or voltage to the high frequency power supply 13, and the power switch 12 is located on the power supply side with respect to the power switch 12. Since the series connection body of the relay 21 that is the second switch and the capacitor 23 for suppressing high frequency noise is connected between the power supply paths having different polarities, the heating operation by the heating coil 14 is performed by opening the power switch 12. It can be stopped reliably. Further, by connecting a series connection body of the capacitor 23 and the relay 21 between the power supply paths immediately after the power switch 12 is closed and disconnecting immediately after the power switch 12 is opened, only when necessary at the time of driving a high frequency power source, etc. Noise can be suppressed by the filter circuit 20 including the common mode coil 22 and the capacitor 23, and the power consumption can be reduced by disconnecting the filter circuit 20 when the power switch 12 is opened.

  In the case of a device having a plurality of heating coils 14, a cooking device capable of reducing the number of parts can be obtained by driving the second switch 21 with the operation means 19.

  In addition, by directly controlling the opening and closing of the relay 21 by the operation means 19 without using the control means 16, when there are a plurality of control means 16, the photo is compared with the case where the relay 21 is driven by the control means 16. The number of parts such as triac can be reduced. Further, in the case where the relay 21 is driven by only one of the plurality of control means 16 without using parts such as a phototriac, when the control means 16 for driving the relay 21 fails, the remaining control means 16 may be operated, so that the heating operation may occur when the relay 21 is open. However, when the operation unit 19 is driven, if the operation unit 19 breaks down, the heating operation of all the control units 16 is impossible. Therefore, the heating operation is not performed when the relay 21 is in the open state, and high-frequency noise generated by the heating operation can be minimized.

  Further, when the relay 21 is closed from open to closed, regardless of whether or not power is supplied to the operation means 19, the power supply phase at the time of changing the contact state is periodically switched so as to average the inrush current and arc. The life of the relay 21 that is the second switch can be prevented from decreasing. In this embodiment, the relay 21 is closed in conjunction with the closing of the power switch 12, and the closing of the relay 21 is normally performed after the operation means 19 is once initialized. Without holding the power supply phase information to the power supply, the periodic switching operation of the power supply phase is virtually impossible, and the effect on the high reliability of the relay 21 is great.

  Furthermore, when the relay 21 is opened from the closed state, similarly to the above-described open to closed state, a plurality of types of power supply phases at the time of changing the contact state are periodically switched regardless of the presence or absence of power supply to the operation means 19. Thus, the arc can be suppressed on average, and the life of the relay 21 as the second switch can be prevented from being reduced.

  When the operation means 19 detects the opening of the relay 21 from the relay open / close detection means 25, the operation means 19 transmits a heating operation stop signal to the control means 16, stops the heating operation, and relay open / close detection means. Since the heating operation cannot be performed by the heating switch while the relay 21 detects the opening of the relay 21 from 25, the high frequency noise generated by the heating operation can be minimized.

  Further, by switching the relay 21 from the closed state to the open state after the power switch 12 is opened from the closed state, the capacitor 23 is connected between the power lines unless the power switch 12 is opened. If the reduction action is stably obtained and the power switch 12 is opened, the power supply is cut off so that no noise is generated. Thereafter, the relay 21 is appropriately opened to generate standby power by the capacitor 23. Can be eliminated.

  In addition, by switching the relay 21 from the open state to the closed state after the power switch 12 is closed from the open state, after the power switch 12 and the relay 21 are both opened, unless the power switch 12 is closed, the capacitor It is possible to prevent the standby power from being generated due to 23.

  Further, since the discharge resistor 24 is connected to both ends of the capacitor 23, the charge accumulated in the capacitor 23 when the input terminal is disconnected from the power source when the power switch 12 is open and the relay 21 is closed. Therefore, it is possible to prevent an electric shock by touching the input terminal.

  Further, in this embodiment, after the power switch 12 as the first switch is changed from open to closed, the relay 21 as the second switch is changed from open to closed, and after the power switch 12 is changed from closed to open. The relay 21 has been described as being open from the closed state, but the operation according to the energization state of the heating coil 14 of the relay 21, that is, closing during the heating operation and opening during the heating stop, the noise as required. In addition, the power consumption required for driving the relay 21 can be suppressed by reducing the chance of closing the relay 21.

The circuit block diagram of the heating cooker in the Example of this invention Timing diagram showing the drive timing of the relay in the same cooking device

Explanation of symbols

10 Input terminal (power supply path)
11 Commercial AC power supply 12 Power switch (first switch)
13 High frequency power supply 15 DC power supply 16 Control means 19 Operating means 21 Relay (second switch)
23 Capacitor for suppressing high frequency noise 24 Discharge resistance

Claims (7)

A heating means, a power supply path for supplying power to the heating means, a first switch provided in the middle of the power supply path and separating the heating means and the power supply, and provided between the power supply paths on the power supply side from the first switch The second switch and the capacitor connected in series, the operating means for operating the heating setting of the heating means, and the control means for controlling the operation of the heating means based on a signal from the operating means, The switch is a heating cooker that opens and closes by directly detecting the drive signal from the operation means without going through the control means. Opening / closing detection means for detecting opening / closing of the second switch is provided, and when the operating means detects that the contact of the second switch is open by the opening / closing detection means during driving of the heating means, heating of the heating means is performed. The cooking device according to claim 1, wherein the operation is stopped. Storage means for holding information regardless of whether power is supplied or not, and the storage means stores a power supply phase when the operation means changes the open / close state of the second switch from open to closed or from closed to open; The cooking device according to claim 1, wherein the operation means switches a plurality of types of power supply phases when changing the open / closed state of the second switch based on information from the storage means. The cooking device according to any one of claims 1 to 3, wherein the second switch is opened or closed according to an energized state of the heating means. The cooking device according to any one of claims 1 to 4, wherein the second switch is opened from the closed state after the first switch is opened from the closed state. The cooking device according to any one of claims 1 to 5, wherein after the first switch is changed from open to closed, the second switch is changed from open to closed. The cooking device according to any one of claims 1 to 6, wherein a discharge resistor is connected to both ends of the capacitor.

Images