JP2010054057A - Cooking device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a user-friendly cooking device with higher safety, for carrying out ON and OFF of a power source by using one operation switch when carrying out power supply by a self-holding relay, improving operability, and closing a relay contact point during abnormality of a signal system carrying out driving of the relay contact point. <P>SOLUTION: An ac power supply 1, a heating part 3 to be a load, and a control part 5 are connected by an excitation type power supply relay 2, feeding to the control part 5 is carried out by using excitation of the power supply relay 2 and passing a current to both ends of a connection of the power supply relay 2 by a non-latch type switch 4, the power supply relay 2 is driven by a driving means 12 to compose self holding, and in a driving method, driving is carried out on the basis of a voltage obtained by charging a voltage of removing direct current components by a differential circuit 13 from a periodic pulse voltage of a rectangular wave or the like. Since a switch opening and closing detection means 8 detects opening and closing states of the switch 4, state transition to both of ON and OFF of a power supply is easily carried out by one switch 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooking device used in general homes, restaurants and offices.

Conventionally, this type of cooking device comprises a first relay contact for connecting an electric heating element (load) and an AC power source as a means for turning on the power, and a switch connected in parallel with the first relay contact. is doing. When the power is turned on, the control circuit is operated by supplying power to the control circuit by operating this switch, and then the first relay contact is closed and self-held by the operable control circuit. When the power is stopped, there is one that releases the holding of the first relay contact by operating a key switch provided in the control circuit (see, for example, Patent Document 1).
JP-A-4-3816

  However, in the conventional configuration, when the power is turned on, the switch connected in parallel to the relay contact is used to connect the power source to the electric heating element (load) and the control circuit, and when stopped, the power switch is released using the key switch provided in the control circuit. Therefore, it is necessary to connect and release the power source by using two switches properly, which has a problem of poor operability.

  Although not clearly shown in the conventional configuration, the relay contact of the drive means is generally maintained by operating the drive means such as a transistor using a DC voltage signal as an original signal and applying an excitation voltage to the excitation coil of the relay. It is realized by applying.

  Therefore, when these control circuits are mounted on a printed wiring board and are electrically connected by wiring of the printed wiring board, a driving signal system (driving means such as a transistor is operated using a DC voltage signal as an original signal). If a malfunction such as a malfunction or failure occurs in the printed wiring path near the source flow side of the signal system) Regardless of the operation, the relay contact is kept closed, and the power supply to the electric heating element is continued.

  The present invention solves the above-described conventional problems, and uses a configuration in which a connection between an AC power source and an electric heating element (load) is held by a relay contact and is self-held by a switching operation of the relay contact by a control operation of a control circuit. In this case, a single operation switch that the user needs to operate is used to improve operability, and a relay operation is performed without relaying a malfunction in the source of the signal system that drives the relay contact to the final stage of the relay drive. An object of the present invention is to provide a cooking device that is easy to use and safer by maintaining the contacts in an open state.

In order to solve the conventional problems, a heating cooker according to the present invention includes a heating unit, a control unit that controls the operation of the heating unit, and one end of the heating unit having one end of the control unit as a common potential. Connected to one end of the AC power source, a power relay connecting the other end of the heating unit and the other end of the AC power source via a connection end, the other end of the control unit and the other end of the AC power source, Connecting through a non-latching switch having a connection end, connecting the potential end on the heating unit side of the power relay and the other end of the control unit, the control unit is a drive means of the power relay, A switch open / close detecting means for detecting an open / closed state of the switch, the switch being connected and connected to the AC power supply by closing the connection end of the switch so that the operation power supply of the controller is generated And the power relay is The AC power source and the heating unit are connected by closing the connection end of the power supply relay by driving with the means, and the driving means applies a pulse voltage with a predetermined cycle and a predetermined amplitude, After the DC component is removed via the differentiation circuit consisting of the first capacitor, the power relay is driven based on the voltage stored in the charging circuit consisting of the second capacitor, and the switch is operated while the power relay is being driven. When the open / close detection means detects that the switch is closed for a first predetermined time or more and less than a second predetermined time, the power relay is opened or after the predetermined operation is completed, It is configured to be in an open state.

  As a result, the AC power supply and the heating part that is the load and the control part are connected by an excitation type power supply relay with the contact point as the connection end, and excitation of the power supply relay is performed at both ends of the connection end of the power supply relay by a non-latching switch. The power is supplied to the control unit and driven by the driving means to have a self-holding configuration, and the driving method is such that a periodic pulse voltage such as a rectangular wave is charged with a voltage obtained by removing a DC component with a differentiating circuit. Because the drive is based on the voltage obtained in this way, in the part before the differentiation circuit, a malfunction such as malfunction or failure in the printed wiring path of the drive signal system, or a problem such as adhesion of foreign matter occurs, and the DC voltage is When the output continues, the drive signal is not transmitted to the final stage of the drive means, and the connection of the power supply relay can be opened to disconnect the AC power supply from the heating unit and the control unit.

  In addition, since the switch open / close detection means can detect the open / closed state of the switch, in addition to the power supply of the initial control unit, it detects the closing of the switch while the power relay is operating (during operation), and stops the operation of the heating unit or the power relay Thus, it is possible to obtain a control timing for opening the power, and it is possible to shift both the power on and off with one switch.

  A single operation switch that the user needs to operate is used to improve operability, and the relay contact is open without transmitting a malfunction in the source of the signal system that drives the relay contact to the final stage of the relay drive. By maintaining the above, it is possible to provide a cooking device that is easy to use and safer.

  1st invention connects a heating part, the control part which controls operation | movement of the said heating part, and the end of the said heating part to the end of AC power supply by making one end of the said control part into a common electric potential, A power relay connecting the other end and the other end of the AC power supply via a connection end, and the other end of the control unit and the other end of the AC power supply via a non-latching switch having a connection end And connecting the potential end on the heating unit side of the power relay and the other end of the control unit, the control unit driving means for the power relay, and a switch open / close detection unit for detecting the open / closed state of the switch The switch is closed and connected to the AC power supply to generate an operation power supply for the control unit, and the power supply relay is connected to the drive means. Drive the connection end of the power relay The AC power supply and the heating unit are closed and the driving unit applies a pulse voltage having a predetermined period and a predetermined amplitude, and a DC component is obtained via a differential circuit including a resistor and a first capacitor. After the removal, the power relay is driven based on the voltage stored in the charging circuit composed of the second capacitor, and the switch open / close detecting means detects that the switch is closed while the power relay is being driven. When detecting for more than a time and less than a second predetermined time, the power relay is opened, or the power relay is opened after completing a predetermined operation.

Thereby, since a heating part and a control part obtain an operation | movement power supply by connecting with AC power supply, according to the drive command of a control part, a heating part can be operated and a to-be-heated material can be heated. The heating unit, control unit, and AC power supply are connected by closing the connection end of the excitation type power relay. Before closing the connection end of this power relay, the control unit and AC power supply must be closed first. By closing the connection end of the non-latching switch that is not held, power supply to the control unit is started, and when the control unit becomes operable, the control unit drives the power relay by the driving means, and the power relay Close the connection end of. At this time, even if the connection end of the switch is opened, the power supply relay is operating, so the connection between the control unit and the AC power supply is maintained. Since the control unit stops driving the power relay after completing a desired operation such as cooking of an object to be heated in the heating unit, the heating unit and the control unit can automatically disconnect the AC power source.

  For driving the power supply relay, a pulse voltage having a predetermined period and a predetermined amplitude is applied by the driving means, a direct current component is removed through a differentiation circuit composed of a resistor and a first capacitor, and then the second relay Based on the voltage stored in the charging circuit consisting of a capacitor, the transistor, etc., provided in the final drive stage is made conductive, so that a current flows through the excitation coil of the power relay, thereby closing the connection end of the power relay and The application of a pulse voltage with a predetermined period and a predetermined amplitude is stopped, the electric charge stored in the charging circuit is discharged, the conduction of the final stage transistor, etc. is interrupted, and the excitation of the exciting coil is stopped, thereby The connection end can be opened.

  In addition, if the control circuit is mounted on the printed wiring board and is electrically connected by the wiring of the printed wiring board, it should be connected to the printed wiring path upstream of the differential circuit of the drive signal system of the power relay. When a malfunction such as malfunction, failure, or adhesion of foreign matter occurs and the DC voltage continues to be output, the DC signal is not transmitted by the differentiation circuit, so that the transistors in the final stage are driven. Is stopped and the connection end of the power relay can be kept open. In addition, when the drive circuit is operated by programming such as a microcomputer, the frequency and duty ratio of the pulses output to the drive circuit are reduced below a specified level due to programming defects or microcomputer runaway. Even in such a case, since the voltage of the charging circuit can be prevented from reaching the driving voltage of the final stage transistor, the driving of the final stage transistor or the like is stopped, and the connection end of the power supply relay can be maintained in the open state. it can.

  In addition, since the switch open / close detection means is provided, even when the power relay is closed, it is possible to detect the closing of the connection end of the switch by a change in the detection voltage, and the power relay is driven after the first predetermined time or more and less than the second predetermined time. Since it stops, the power supply of the alternating current power supply to an apparatus can be stopped intentionally by the user. That is, both the open and closed states of the power relay can be operated by operating the switch. Thus, it is easy to use and can improve safety.

  In the second aspect of the invention, in particular, the drive means of the first aspect of the invention is a rectangular pulse waveform of a pulse voltage having a predetermined period. As a result, the square wave is a waveform that can be output relatively easily by turning on and off the transistor of the output terminal by a digital IC, such as a microcomputer, by internal programming, so that an increase in the number of components of the driving means can be suppressed. At the same time, even if a malfunction occurs in which the output terminal of the microcomputer is destroyed or the output of the output terminal is fixed to a DC voltage output state due to a program runaway, the differentiation circuit of the driving means converts the DC voltage component. Since the charge circuit is not charged, the driving of the power supply relay is stopped, and the connection between the heating unit and the AC power supply of the control unit can be cut off, and the safety can be further improved.

  According to a third aspect of the invention, in particular, the control unit of the first or second aspect of the invention has a notification unit, and when the switch opening / closing detection unit detects that the switch is closed for a second predetermined period or more, the notification is performed. In addition to notifying by means, the power relay is opened. As a result, if the connection end of the switch may remain in a closed state due to some trouble, the notification means notifies the user, and power supply from the AC power source to the heating unit can be stopped. It is possible to prompt the user to take appropriate measures such as repairing by contacting the user.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 and 2 are block diagrams of the heating cooker according to the first embodiment of the present invention, and FIG. 3 is an operation waveform of each part of the driving means of the heating cooker according to the first embodiment of the present invention (in a steady state). FIG. 4 is an operation waveform (at the start of operation) of each part of the driving means of the cooking device according to the first embodiment of the present invention. The difference between FIG. 1 and FIG. 2 is only the connection method of the second bypass means 7, and there is no difference in the operation.

  In FIG. 1, one end of an AC power source 1 is connected to a heating unit 3 via a contact that is a connection end of a power relay 2, and a connection of a non-latching switch 4 that closes the connection end only while being operated. It is also connected to the control unit 5 via a contact that is an end and a reverse blocking type first bypass means 6 such as a diode that bypasses current in the direction from the switch 4 to the control unit 5.

  Furthermore, the connection part between the power relay 2 and the heating part 3 includes a diode for bypassing current in the direction from the connection part between the power relay 2 and the heating part 3 to the connection part between the first bypass means 6 and the control part 5. The reverse blocking type second bypass means 7 is connected. The other end of the AC power source 1 is connected to the other end of the heating unit and the other end of the control unit.

  In addition, a switch open / close detection means 8 is connected to a connection portion between the switch 4 and the first bypass means 6 to monitor the open / closed state of the connection end of the switch 4.

  The control unit 5 includes a rectifier circuit 9 that rectifies the voltage of the AC power supply 1, a control power supply circuit 10 that generates an operating voltage from the output of the rectifier circuit 9, and a microcomputer 11 that operates with the power supply voltage generated by the control power supply circuit 10. Including a driving means 12 for driving the power relay 2 by excitation.

  The driving means 12 converts a rectangular pulse having a predetermined period and a predetermined amplitude output from the microcomputer 11 into a voltage from which a DC component has been removed by a differentiating circuit 13 including a first capacitor 13a and a resistor 13b, and this voltage is converted into a second voltage. The charging circuit 14 including the capacitor 14a holds, and the charged voltage causes the transistor 15 at the final stage to conduct so that a current flows through the exciting coil 2a of the power relay 2 to drive the power relay 2.

  In addition, the notification means 16 including a display element such as an LED or a buzzer performs notification and display according to the operation state of the control unit 5 to indicate the operation state of the device to the user.

  About the cooking-by-heating machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, when the user operates the switch 4, the AC power supply 1 and the control unit 5 are connected via the first bypass means 6, and the voltage rectified by the rectifier circuit 9 is applied to the control power supply circuit 10. A control power supply is generated.

  With this control power source, the microcomputer 11 starts its operation and, as shown in FIG. 4 (4a), to drive the power relay 2 to the driving means 12, the peak value is 5V with reference to 0V of the control power source, the period A rectangular wave of about 2 ms and a duty ratio of about 50% is output. Since the rectangular wave is a waveform that can be output relatively easily by turning on and off the transistor of the output terminal by programming inside the microcomputer 11, the increase in the number of components of the driving means is suppressed.

  When this rectangular wave is applied to the differentiating circuit 13, a voltage as shown in FIG. 4 (4c) in which the DC component of the rectangular wave is removed by the first capacitor 13a and the resistor 13b is generated in the resistor 13b. .

  This voltage is stored in the second capacitor 14a connected in the reversely blocked state by the diode, and increases as shown in FIG. 4 (4d). In this embodiment, when the voltage reaches about 2.5V, the transistor 15 Is made conductive, a current is passed through the exciting coil 2a, and the contact which is the connection end of the power supply relay 2 is closed.

  Further, the waveform of each part in FIG. 4 becomes stable as shown in FIG. At this time, the control unit 5 is connected to the AC power source 1 through the second bypass unit 7, and power is supplied from the AC power source 1 through the path of the power relay 2 and the second bypass unit 7.

  For this reason, even if the user stops the operation of the switch 4 at this time and the connection between the switch 4 and the AC power supply 1 in the path of the first bypass means 6 is lost, the control unit 5 continues to generate the operation power supply. In addition, other operating states can be maintained.

  The second bypass means 7 is configured such that the switch 4 is operated in a state where the power relay 2 is closed, the heating unit 3 is in operation and the load current is flowing, and the AC power source 1, the switch 4, and the heating unit 3 are routed. The load current of the heating unit 3 is prevented from flowing.

  Thereafter, when the user operates the switch 4 again for the first predetermined time or more and less than the second predetermined time, the switch open / close detection means 8 detects the closing of the connection end of the switch 4, and the microcomputer 11 detects the first predetermined time. By stopping the pulse output to the drive means 12 after a time, the drive of the power supply relay 2 is stopped, and the power supply from the AC power supply 1 to the heating unit 3 and the control unit 5 is stopped.

  The first bypass means shuts off the current to the switch open / close detection means 8 by the first bypass means 6 even when the power supply relay 2 is closed and the switch 4 is open. When closed, the voltage change occurs at the connection between the switch 4 and the first bypass means 6 so that the open / closed state of the switch 4 can be determined.

  Further, even if the user does not operate the switch 4, the heating operation in the heating unit 3 is completed, and after the desired operation is completed, the driving of the power supply relay 2 is automatically stopped, and the heating unit 3 and the control unit are controlled. By stopping the power supply from the AC power supply 1 to the unit 5, standby power consumption due to the user forgetting to cut can be suppressed.

  When the switch opening / closing detection means 8 detects the closing of the switch 4 continuously for the second predetermined time or more, it is considered that the switch 4 or the switch opening / closing detection means 8 has failed, and the heating unit 3 is in operation. If there is, the operation is stopped, and the notification means 16 notifies the user that the failure has occurred, the drive of the power relay 2 is also stopped, the connection end is opened, and the heating unit 3 and the control unit via the power relay 2 The power supply of the AC power supply 1 to 5 can be stopped, and the user can be encouraged to take appropriate measures such as contacting the manufacturer for repairs, and the safety of the equipment can be improved.

The driving means 12 is configured to maintain the conduction of the final stage transistor 15 with the voltage obtained as a result of passing through the differentiation circuit 13 and the charging circuit 14 starting from the rectangular pulse as described above. Also, signal abnormality in the previous stage, for example, a DC voltage state including 0V of drive pulse output due to runaway of the microcomputer 11, or the control unit 5 is arranged on the printed wiring board, and the printed wiring forms an electrical connection. In this case, in the DC voltage output state to the differential circuit 13 due to malfunction or failure in the printed wiring path upstream of the differential circuit of the drive signal system of the power supply relay or the adhering of foreign matter, the final stage transistor 15 Is not driven, and the connection end of the power supply relay 2 is kept open, further improving the safety of the device.

  In addition, when the second bypass means 7 is connected as shown in FIG. 2, when the power relay 2 is closed, the rectifier circuit 9 is full-wave rectified, and the operation efficiency of the control power circuit 10 is increased. Since the electrical duty of the parts is reduced, the components can be downsized.

  As described above, in this embodiment, the AC power source 1 is connected to the heating unit 3 serving as a load and the control unit 5 by the excitation type power relay 2 having a contact as a connection end. A non-latching switch 4 conducts both ends of the connection end of the power relay 2 to supply power to the control unit 5 and is driven by the driving means 12 to have a self-holding configuration. Is driven on the basis of the voltage obtained by charging the voltage obtained by removing the DC component in the differentiating circuit 13, so that the printed wiring of the drive signal system is provided in a portion preceding the differentiating circuit 13. When a malfunction such as malfunction or failure occurs in the path, or when a DC voltage is continuously output due to a problem such as adhesion of foreign matter, the drive signal is not transmitted to the transistor 15 at the final stage of the drive means 12 and the power supply Open the connection end of relay 2 AC power supply 1 and the heating unit 3 Te, cut off the connection of the control unit 5, it is possible to enhance the safety of the equipment.

  In addition, since the switch open / close detection means 8 can detect the open / closed state of the switch 4, in addition to the power supply of the initial control unit 5, it detects the closing of the switch 4 during driving of the power supply relay 2 and stops the operation of the heating unit 3. The control timing for opening the power supply relay 2 can be obtained, and it is possible to shift both the power-on and power-off states with a single switch 4, thereby improving the usability of the device.

  In this embodiment, only one heating unit is used. However, the same effect can be obtained even when a plurality of heating units are provided. If the current capacity at the connection end of the power relay is insufficient, the corresponding heating unit is used. It goes without saying that the same effect can be obtained by providing power relays and connecting one power relay to the control unit.

  As described above, the heating cooker according to the present invention has a resistance load, an induction heating unit, and a dielectric heating unit that use electric energy as a heating unit, and is a mode in which the user turns on / off the power. Therefore, it is effective for an electric cooker such as an oven microwave oven equipped with a sheath heater for a roaster, an IH cooking heater equipped with a radiant heater, a sheathed heater for an oven, or the like.

The block diagram of the heating cooker in Embodiment 1 of this invention The block diagram of the heating cooker in Embodiment 1 of this invention FIG. 6 is an operation waveform (steady state) of each part of the driving means of the heating cooker in the first embodiment of the present invention. FIG. 6 is an operation waveform (at the start of operation) of each part of the driving unit of the cooking device according to the first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC power supply 2 Power supply relay 3 Heating part 4 Switch 5 Control part 8 Switch opening / closing detection means 12 Drive means 13 Differentiation circuit 13a 1st capacitor | condenser 13b Resistance 14 Charging circuit 14a 2nd capacitor | condenser 16 Notification means

Claims (3)

A heating unit, a control unit that controls the operation of the heating unit, and one end of the heating unit is connected to one end of an AC power source using one end of the control unit as a common potential, and the other end of the heating unit and the AC power source A power relay that connects the other end of the AC power supply via a connection end; and the other end of the control unit and the other end of the AC power supply are connected via a non-latching switch having a connection end; A potential end on the heating unit side and the other end of the control unit are connected, and the control unit includes a driving unit for the power supply relay and a switch open / close detection unit for detecting an open / closed state of the switch. When the connection end is closed and the AC power supply is connected, the operation power supply of the control unit is generated, and the power supply relay is driven by the drive means to operate. Close the connection end of the relay and The power source and the heating unit are connected, and the driving unit applies a pulse voltage having a predetermined period and a predetermined amplitude, and after removing a DC component through a differential circuit including a resistor and a first capacitor, The power relay is driven based on a voltage stored in a charging circuit comprising a second capacitor, and the switch open / close detection means keeps the switch closed for a first predetermined time or more during the driving of the power relay. A cooking device that, when detected for less than a predetermined time, opens the power supply relay or opens the power supply relay after completing a predetermined operation. The cooking device according to claim 1, wherein the driving means has a rectangular pulse waveform of a pulse voltage having a predetermined period. The control unit includes a notification unit, and when the switch opening / closing detection unit detects that the switch opening / closing detection unit is in a closed state for a second predetermined period or longer, the control unit notifies the notification unit and opens the power relay. Or the heating cooker of 2.

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