JP2007149415A - Heating cooker using power supply switch having no locking mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker having a power supply switch always turning off without a locking mechanism which cuts off power supply route to a heating portion, even if a contact of power supply switch becomes locked by incorrect operation and controls to secure safety. <P>SOLUTION: When a contact of a latch relay 3 is closed, even if a contact of the power supply switch 2 continues a closed state, an opening retaining means holds the contact of the latch relay 3 in open state, when the contact of the latch relay 3 is open, even if the contact of the power supply switch 2 continues a closed state, a compulsory turning off means 6 cuts off power supply to a closed winding drive means 4 and controls so as not to hold the latch relay 3 in closed state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electric cooker used for general households and business use, and in particular, the power supply to the control circuit of the device continues even after the power switch is turned off to perform necessary control such as high temperature notification / display. The present invention relates to a heating cooker using a power switch that does not have a lock mechanism that has a function of cutting off power supply to a control unit and reducing standby power when control becomes unnecessary.

  Conventionally, even after the contact of the power switch that supplies power to the heating unit is opened, the power supply to the control unit is continued, the top plate temperature is monitored to indicate whether the temperature is high, the device outline or the inside When the temperature of the motor is monitored and the fan motor for cooling is driven to prevent performance deterioration due to the temperature rise of internal electronic components due to the remaining heat of the heating unit, display, notification, or cooling of the equipment is no longer necessary Discloses a cooking device according to Conventional Example 1 in which power supply to a control unit is cut off in order to reduce standby power (see, for example, Patent Document 1).

  Hereinafter, the cooking device of Conventional Example 1 will be described with reference to FIG. FIG. 2 includes a heating unit 31, and a heated object such as a pan is placed on the heating unit 31 for cooking. One input terminal of the heating unit 31 is connected to the commercial power supply 34 via the power switch 32, and the other input terminal is connected to the commercial power supply 34 via the fuse 33.

  A full-wave rectifier circuit including a rectifier 35d, a rectifier 35e, a rectifier 35f, and a rectifier 35g is connected to the input terminal of the heating unit 31, and a positive electrode output terminal between the rectifier 35d and the rectifier 35f and a negative electrode output terminal. Between a connection point of a rectifier 35e and a rectifier 35g, a heating coil 31a, a capacitor such as a resonance capacitor and a smoothing capacitor, a circuit block 31b including a diode and a switching element, and an insulated gate bipolar transistor 31c (hereinafter referred to as IGBT). ) Etc. are connected.

  The output terminal of the control unit 36 is connected to the gate and emitter of the IGBT 31c, and the common potential of the control unit 36 is the same as the emitter of the IGBT 31c, the anode of the rectifier 35e, and the anode of the rectifier 35g. Further, the control unit 36 includes a microcomputer, an input means 36a for the user to input a control command, a temperature detection means 36b for detecting the temperature of the outer or inner portion of the cooker, and the operating state or temperature of the device to the user. An informing means 36c for informing is provided.

  A power supply circuit 37 having a switching power supply 37a for supplying a smoothed DC voltage for control to the control unit 36 is provided. The common potential of the power supply circuit 37 is the same as the common potential of the control unit 36. The other input terminal of the circuit 37 is connected to a rectifier 38 comprising a rectifier 38a and a rectifier 38b and a cathode side of the rectifier 39. The anode of the rectifier 38 a is connected to the load side terminal of the power switch 32, the anode of the rectifier 38 b is connected to the power source side terminal of the fuse 33, and the anode side of the rectifier 39 is connected to one contact of the control power relay 40. The other contact of the control power relay 40 is connected to the power supply side terminal of the power switch 32. The control terminal of the control power supply relay 40 is connected to the control unit 36.

  The operation of the electric cooker configured as described above will be described.

  When the power switch 32 is closed, the commercial power supply 34 → the power switch 32 → the rectifier 38a → the power supply circuit 37 input terminal → the power supply circuit 37 common potential → the rectifier 35g → the fuse 33 → the path of the commercial power supply 34 (hereinafter referred to as the first power supply path 41). ), A half-wave direct current is supplied to the power supply circuit 37, and a commercial power supply 34 → rectifier 38b → power supply circuit 37 input terminal → power supply circuit 37 common potential → rectifier 35e → power switch 32 → commercial power supply 34 path (also this) The half-wave direct current is supplied to the power supply circuit 26 through the first power supply path 41 hereinafter. Full-wave rectified direct current is input to the power supply circuit 37 through the first power supply path including the power switch 32 and the rectifier 38a and the first power supply path including the power switch 32 and the rectifier 38b.

  Further, by closing the control power supply relay 40, the commercial power supply 34 → the control power supply relay 40 → the rectifying means 39 → the power supply circuit 37 input terminal → the power supply circuit 37 common potential → the rectifier 35g → the fuse 33 → the path of the commercial power supply 34 (hereinafter referred to as “the power supply 34”). 2) (referred to as the second power supply path 42), the half-wave direct current can be supplied to the power supply circuit 37 in the same manner as the first power supply path. Is supplied with power.

  The control unit 36 performs opening / closing control of the contact of the control power relay 40 constituting the second power path 42.

  When a heating command is input to the input unit 36a, the control unit 36 outputs a drive signal to the gate terminal of the IGBT 31c inside the heating unit 31, and generates a high-frequency magnetic field by flowing a high-frequency current through the heating coil 31a. Although not specifically shown in the figure, an object to be heated such as a pan placed on the heating coil 31a is heated.

  The temperature detection means 36b monitors the temperature of the top plate on which the equipment shell, pan, etc. are placed, the temperature of the IGBT 31c, etc., and the control means 36 stops driving the IGBT 31c or determines the drive time based on this information. It is possible to suppress the output of the heating unit 31 by performing control, or to perform abnormal temperature notification or temperature display by the notification means 36c.

  When the cooking by the heating unit 31 is finished and the power switch 32 is opened, the power supply to the heating unit 31 is cut off, but the power supply to the control means 36 is made through the second power supply path 42. In addition, the driving of the IGBT 31c can be stopped and the display notification by the notification means 36c can be changed to the display notification corresponding to the power switch off.

  At this time, if the temperature of the top plate on which the object to be heated such as a pan measured by the temperature detection means 36b or the temperature of the IGBT 31c is higher than about 65 ° C. or there is no control command from the user continuously for a predetermined time. If it is necessary to confirm this, the control power supply relay 40 is continuously driven to supply DC power to the control unit 25 so that it can be operated. Drives the fan motor.

  Thus, the control unit 36 can continuously notify the user that the top plate temperature is hot by the notification unit 36c, or drives the cooling fan motor until the temperature of the IGBT 31c drops below a predetermined temperature. Finally, the control power relay 40 can be shut off, and the power supply to the power circuit 27 can be shut off.

  Since the fuse 33 is not included in the first power supply path that ends at one end of the commercial power supply 34 → the rectifier 38 b → the power supply circuit 37 → the rectifier 35 e → the power switch 32 → the other end of the commercial power supply 34, the fuse 33 Even if a failure occurs that melts 33, the control unit 37 becomes operable by closing the power switch 32, and a control operation such as notifying the failure state of the device by the notification means 37c can be performed.

  As described above, according to the conventional example 1, since the power supply switch 32 that directly supplies or cuts off the power to the heating unit 31 is provided, regardless of the failure or runaway of the microcomputer inside the control unit, The heating operation can be stopped reliably.

  On the other hand, in the conventional configuration, the power supply to the heating unit is cut off by the user mechanically opening the contact point of the power switch. In order to perform the protection operation, the power supply to the control unit is maintained.

  Therefore, since the power supply to the heating unit continues unless the user intentionally shuts off the contact point of the power switch, if the power switch is inadvertently forgotten to turn off, the device may run away due to external noise. .

  As a configuration for solving the problem, it is easy to use the power switch configuration of Conventional Example 2 (for example, see Patent Document 2).

  The configuration of the power switch of Conventional Example 2 will be described below with reference to FIG. FIG. 3 includes a heating unit 31 that is a power supply unit, and an object to be heated such as a pan is placed on the heating unit 31 for cooking. The power switch 51 includes an interlocking switch contact 51a and a switch contact 51b, and the first relay 52 includes a first relay drive winding 52a and a first relay contact 52b. The second relay 53 includes a second relay drive winding 53a and a second relay contact 53b, and includes a control unit 54.

  The operation of the electric cooker configured as described above will be described.

  When the switch contact 51a is closed, a current flows through the first relay drive winding 52a, the first relay contact 52b is closed, and power is supplied to the control means 54 and the heating unit 31. When power is supplied to the control means 54, the second relay drive winding 53a is driven, so that the second relay contact 53b changes from open to closed, the operation of the power switch 51 is stopped, and the switch contact 51a is opened. Even so, the first relay contact 52b continues to be closed.

  Thereafter, when the power switch 51 is operated to close the switch contact 51b, the control means 54 stops driving the second relay drive winding 53a, so that the first relay contact 52b changes its state from closed to open.

  However, when a situation occurs in which the switch contact 51a of the power switch 51 continues to be closed due to foreign matter adhering to the power switch 51, the first relay contact 52b continues to be closed and power is supplied to the heating unit 31. Therefore, even if the power switch 51 is operated, the power supply to the heating unit 31 cannot be cut off.

Further, since the control means 54 drives the second relay 53 and holds the drive of the first relay drive winding 52a, when the control means 54 runs away due to external noise, the control means 54 sends a signal from the power switch 51. And the operation of the first relay 52 is continued, so that the heating operation cannot be stopped by the power switch 51 even when the heating unit 31 as the power supply unit is performing the heating operation. there is a possibility.
Japanese Patent No. 3460614 JP-A-8-322145

  However, in the configuration of the power switch of the conventional example 1, after the user operates the power switch to turn off the cooker and then the cooling of the electronic components is not necessary, all control power is shut off. However, if the user forgets to turn off the cooker, the control power supply cannot be cut off.

  Further, as in the conventional example 2, the relay for turning on / off the power supply to the power supply unit, the power switch for driving the relay when operated with the power off at all times, and the relay in conjunction with the operation of the power switch In the configuration including the control means for driving, the control means continues to drive the relay, for example, when a foreign substance adheres to the sliding portion of the power switch and the contact of the power switch continues to be on. When the switch cannot be operated, or when the opening / closing of the power switch cannot be recognized, there is a problem that even if the user operates the power switch, the power to the heating unit that is the power supply unit cannot be cut off.

  The present invention solves the above-described problem. For example, when the user forgets to turn off the power switch or when the user presses the power switch for a long time, the power to the closed winding drive circuit is shut off. An object of the present invention is to provide a cooking device using a power switch that does not have a lock mechanism that can be surely shifted to an off state.

  In order to solve the conventional problem, a cooking device using a power switch that does not have a lock mechanism according to the present invention includes a power switch that does not have a lock mechanism, a latch relay that includes a latching mechanism, and the latch. A heating unit that can supply power when the relay contact is closed, contact detection means for detecting the contact state of the latch relay, closed winding drive means for closing the contact of the latch relay, and a contact of the latch relay An open-winding drive means that opens, an open-holding means that keeps the contact of the latch relay in an open state, and detects that the contact of the latch relay is in a closed state, and cuts off the power supply to the closed-winding drive means Forcibly off means, and when the contact of the latch relay is closed, the contact of the power switch is closed and the contact of the latch relay is changed to open. When the contact of the latch relay is in the closed state, the open holding means holds the contact of the latch relay in the open state, and when the contact of the latch relay is open, the contact of the power switch is closed and the contact of the latch relay is If the contact of the power switch continues to be closed after changing to the closed state, the forced-off means shuts off the power supply to the closed winding drive means and does not keep the latch relay contact in the closed state. Is to do.

  As a result, when the cooking device is on, even if the user operates the power switch and changes the state to off, the contact of the latch relay is held in the open state by the open holding means. Thus, since the state is not changed to ON, an operation different from the case where the user operates the power switch to change the state to ON when the state is OFF can be realized.

  Further, when the state of the heating cooker is off, the forced-off means is a drive circuit that closes the contact of the latch relay even if the user continuously operates after operating the power switch to change the state to on. Since the power supply to the closed winding drive circuit is cut off, the contact of the latch relay can be opened at any time, and the open winding drive means for cutting off the power supply to the load such as a heater can be reliably performed.

  As a result, even if the user forgets to turn off the power switch or presses the power switch for a long time, the power to the closed-winding drive circuit is shut off to ensure the transition to the off state. Can do.

  The cooking device using the power switch that does not have the lock mechanism of the present invention is a closed winding drive circuit even when the user forgets to turn off the power switch or when the user presses the power switch for a long time. It is possible to realize a sure transition to the off state by shutting off the power to the.

  According to a first aspect of the present invention, there is provided a power switch that does not have a lock mechanism, a latch relay that includes a latching mechanism, a heating unit that can supply power when the contact of the latch relay is closed, and a contact state of the latch relay. Contact detection means for detecting; closed winding drive means for closing the contact of the latch relay; open winding drive means for opening the contact of the latch relay; and open holding means for holding the contact of the latch relay in an open state; Forcibly turning off the power supply to the closed winding drive means by detecting that the contact of the latch relay is closed, and when the contact of the latch relay is closed, the contact of the power switch If the contact of the switch continues to be closed after the latch relay contact is changed to open, the open holding means holds the latch relay contact in the open state. In addition, when the contact of the power supply switch is closed and the contact of the power supply switch is continuously closed after the contact of the power supply switch is closed and the contact of the power supply switch is closed, Performs control so that the power supply to the closed winding drive means is cut off and the contact of the latch relay is not held in the closed state.

  With this configuration, for example, even when the user forgets to turn off the power switch or when the user presses the power switch for a long time, the power to the closed-winding drive circuit is cut off, so the power switch is turned off. It is possible to move reliably.

  In the second aspect of the invention, particularly when the forced-off means of the first aspect of the invention is continued after the contact of the latch relay is changed from open to closed, and the contact of the power switch is kept closed for a predetermined time, the open winding drive is performed. The power switch is kept pressed by contact welding of the power switch, misoperation of the user, biting of foreign matter, etc. by performing a forced off operation that changes the contact of the latch relay to the open state by operating the means. However, the equipment can be shut down safely.

  In the third invention, in particular, when the power switch of the first invention or the second invention is closed only when the contact of the latch relay is open, that is, when the power of the device is off, By adopting a configuration in which power is supplied to the closed winding driving means, standby power for closing the contact of the latch relay can be reduced.

  According to a fourth aspect of the invention, in particular, when the contact of the latch relay according to any one of the first to third aspects is closed, power is supplied to the open winding drive means, and the contact of the power switch is closed. After detecting the change from open to open, the latch relay contact is opened to cut off the power supply to the open winding drive means, so that the latch relay contact is open, that is, the device power is off. In standby mode, unnecessary standby power consumed by a circuit for opening contacts can be reduced.

  In the fifth aspect of the invention, in particular, the open-winding drive means of any one of the first to fourth aspects of the invention is configured such that the power supply is made by closing either the contact of the latch relay or the contact of the power switch. This reduces the standby power for opening the contacts that are not necessary when the latch relay contacts are open, that is, when the power supply of the device is off, and power is supplied to the open winding drive means. By supplying power to the open holding means, even if the contact of the power switch continues even after the contact of the latch relay changes from closed to open, and the contact of the power switch continues to be closed, It is possible to reliably keep the latch relay contact in the open state.

  In the sixth invention, in particular, the forced-off means of any one of the first to fifth inventions after the power supply to the closed-winding drive means is interrupted after the contact of the latch relay is changed from open to closed. Even if the contact of the latch relay changes from closed to open, if the contact of the power switch continues to be closed, power is not supplied to the closed winding means and the interruption is continued. By adopting a configuration that enables power supply to the closed-winding drive means at the time of opening, the contact of the power switch continues to be closed when the device is off, and the latch relay contact is temporarily closed. Even in this state, the open winding drive means that shuts off the power supply to the closed winding drive circuit and opens the contact of the latch relay is prioritized and can operate reliably.

  In particular, the seventh aspect of the invention includes the heating unit of any one of the first to fifth aspects of the invention, including a control unit capable of measuring time, the contact of the latch relay is kept closed for a predetermined time, and the heating operation If the setting to change the mode to the heating state (such as a timer) is not made, the control means performs control to open the contact of the latch relay, so that the user turns on the power of the device. Even if the power switch is inadvertently left unattended and left unattended, the latch relay contacts can be opened after a predetermined period of time, thereby preventing erroneous operation and malfunction and ensuring safety.

  In particular, the eighth invention includes a high-current relay that supplies / cuts off electric power to the heating unit of claim 1, and the contact of the high-current relay opens and closes in conjunction with the contact of the latch relay. As a result, a low-power latch relay can be used, so there is little drive power, and a compact, low-cost power switch with low contact current capacity can be used. The response speed of the power switch when turning on the power can be increased.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, this invention is not limited by the form of this invention.

(Embodiment 1)
FIG. 1 shows a circuit configuration of a heating cooker using a power switch that does not have a locking mechanism in the first embodiment of the present invention.

  In FIG. 1, the contact point of the power switch 2 connected to the commercial power source 1 is normally in a normally open state, and the contact point is closed only when pressed by the user. The latch relay 3 includes a latch relay contact 3a, a closed winding 3b, and an open winding 3c.

  A closed winding driving means 4, a first switching element 5, a forced-off means 6, and a timing means 7 are provided. The timing means 7 is provided in the forced-off means 6, and when the contact of the power switch 2 is closed, the forced-off means 6 is provided. The forced-off means 6 starts measuring the time during which the contact of the power switch 2 is closed by the time measuring means 7. The forced off means 6 turns on the first switching element 5 and supplies power to the closed winding drive means 4. The closed winding driving means 4 to which power is supplied closes the latch relay contact 3 a by causing a current to flow through the closed winding 3 b constituting the latch relay 3.

  A contact detection means 8, a main power contact driving means 9, and a main power relay 10 are provided. The main power relay 10 is composed of a main power contact 10a and a main power winding 10b. The main power contact 10a is energized and driven by the main power contact driving means 9 provided, and the main power contact 10a opens and closes in conjunction with the latch relay contact 3a. Further, the contact detection means 8 transmits information that the latch relay contact 3 a is changed to the closed state to the forced-off means 6.

  When the forced-off means 6 receives information from the contact detection means 8 that the latch relay contact 3a is in a closed state, the forced-off means 6 turns off the first switching element 5 and cuts off the power supply to the closed winding drive means 4.

  The inverter (heating unit) 11 includes a switching element 11a and a rectifying element 11b as components, and is connected to a load side terminal of the main power contact 10a to supply a high-frequency current to the induction heating coil 12, thereby The pan 13 placed on the heating coil 12 is heated.

  The control unit 14 includes an operation unit 14a, a display unit 14b, a temperature detection unit 14c, a cooling unit 14d, a timer unit 14e, and the like. The operation unit 14a allows the user to control the thermal power and timer operation output from the inverter 11. Setting is possible, and the setting contents are displayed on the display unit 14b. Further, when the temperature of the outer shell and components of the cooking device is detected by the temperature detection unit 14c and the temperature needs to be cooled, the cooling unit 14d such as a fan motor is driven, and the timer unit 14e It is discriminated that the operation has been continued for a predetermined time or more in a state where is turned on.

  An open-winding drive means 17, a first rectifier element 18a, and a second rectifier element 18b are provided. When the contact of the power switch 2 is closed, power is supplied to the open-winding drive means 17 by the first rectifier element 18a, and the latch When the relay contact 3a is closed, electric power is supplied to the open winding drive means 17 by the second rectifying element 18b. When power is supplied to the open-winding drive means 17, the open-winding drive means 17 drives the open-winding 3c and opens the latch relay contact 3a by a signal from the forced-off means 6 or the control means 14.

  The open holding means 19 detects that the latch relay contact 3a is closed by the contact detection means 8, and outputs a signal to the forced-off means 6 and the open winding drive means 17, and the contact of the power switch 2 is closed. After the latch relay contact 3a is opened, the output operation of the forced-off means 6 and the open winding drive means 17 is continued until the contact of the power switch 2 is opened.

  The first power supply circuit 20, the second power supply circuit 21, and the control power supply relay 22 are provided. When the latch relay contact 3 a is closed, power is supplied from the first power supply circuit 20 to the control unit 14. Drive. The second power supply circuit 21 supplies power to the control unit 14 from the control power supply relay 22, and can continue to supply power to the control unit 14 even after the latch relay 3 is turned off, thereby detecting temperature, cooling, and displaying. The standby power can be reduced by turning off the control power relay 22 when notification is no longer necessary.

  The forced-off means 6 measures the time during which the contact of the power switch 2 is closed by the time measuring means 7, and if the contact of the power switch 2 is closed even after a predetermined time has elapsed, the device has failed or has been used. The first switching element 5 is turned off, the power supply to the closed winding drive means 4 is cut off, a drive signal is output to the open winding drive means 17, and the open winding drive means 17 Opens the latch relay contact 3a.

  The control unit 14 includes a timer unit 14e, and if it is not operated even after a predetermined time has passed, it is determined that the user has forgotten to turn off the power, and the control unit 14 issues a power-off command to the open winding drive unit 17, The open winding drive means 17 opens the latch relay contact 3a.

  The operation and action of the circuit configuration of the cooking device using the power switch that does not have the lock mechanism configured as described above will be described below.

  First, when the user operates the power switch 2 in the power-off state, the contact of the power switch 2 is closed and power is supplied to the forced-off means 6, the open winding drive means 17, and the open holding means 19. The forced-off means 6 to which power is supplied recognizes from the signals from the contact detecting means 8 and the open holding means 19 that the power switch 2 has been operated while the latch relay contact 3a is open, and the first switching element 5 is turned on to start supplying power to the closed winding drive means 4 and measuring the time during which the contact of the power switch 2 is closed by the time measuring means 7. The closed winding driving means 4 supplied with power drives the closed winding 3b of the latch relay 3 to close the latch relay contact 3a. The contact detection means 8 detects that the latch relay contact 3a is closed, transmits contact information to the forced-off means 6 and the open state holding means 19, and drives the main power relay winding 10b to drive the main power relay contact. Close 10a.

  When the forced-off means 6 recognizes a signal indicating that the latch relay contact 3 a transmitted from the contact detection means 8 is in a closed state, the forced-off means 6 turns off the first switching element 5 and cuts off the power supply to the closed winding drive means 4. Thus, the operation of the open winding drive means 17 is ensured.

  Further, when the latch relay contact 3a is closed, power can be supplied to the open winding drive means 17 and the open holding means 19 via the second rectifying element 18b and the latch relay 3, and therefore the contact of the power switch 2 Even if is opened, the open winding driving means 17 and the open holding means 19 continue to operate.

  In the present embodiment, the forced-off means 6 is configured to supply power only when the contact of the power switch 2 is closed. However, like the control means 14, the forced-off means 6 continues when the cooker is in the power-on state. Even if power is supplied, the operation of the present invention is not particularly different, and substantially the same effect can be obtained. However, by supplying power only when the power switch 2 is closed, the energization time is reduced, noise and the like. This reduces the chance of malfunction of the electronic circuit.

  The time measuring means 7 measures the time during which the contact of the power switch 2 is closed after the contact of the power switch 2 is closed and power is supplied to the closed winding drive means 4, and the latch relay contact 3 a is detected from the contact detection means 8. Even if the signal indicating that it is in the closed state is not received, it is determined that the contact of the power switch 2 is abnormal when the contact of the power switch 2 is normally closed for about 2 seconds, for example. . When the power switch 2 is abnormal, the forced-off means 6 turns off the first switching element 5 to cut off the power supply to the closed-winding drive means 4 and transmits a forced-open drive signal to the open-winding drive means 17. The open winding driving means 17 drives the open winding 3c based on the signal regardless of the state of the latch relay contact 3a to turn off the latch relay 3.

  The contact detection means 8 detects the opening and closing of the latch relay contact 3a and drives the main power supply winding 10b by the main power supply winding drive means 9 so that the latch relay contact 3a and the main power supply relay contact 10a are interlocked. The contact information signal of the latch relay contact 3a is output to the forced-off means 7, the open winding drive means 17, and the open holding means 19.

  When the main power supply relay contact 10a is closed, power can be supplied to the inverter 11, the switching element 11a constituting the inverter 11 is turned on and off, and the DC voltage rectified by the rectifying element 11b is converted into an AC voltage, thereby heating the coil. The load 13 such as a pan is heated by applying a high frequency current to the heating coil 12 by biasing to 12.

  The control means 14 has a function of controlling the inverter 11, and the user inputs the thermal power and the timer time to the operation unit 14a, and the setting contents are shown to the user by the display notification unit 14b. The temperature detection unit 14c measures the electronic components and outline temperature inside the cooking device, and outputs information to the operation unit 14a. The operation unit 14a operates the cooling unit 14d as necessary.

  When the timer unit 14e determines that the state in which the device is not operated and is not operated in a state where the power source of the device is turned on continues for a predetermined time or longer, the control unit 14 causes the open winding drive unit 17 to operate. Drive to turn off the device.

  Further, the first power supply 20 supplies power to the control means 14 when the latch relay contact 3a is closed, and the control means 14 notifies the user that the device is in the ON state by the display notification unit 14b.

  After the power is supplied to the operation unit 14a, when the user inputs the start of heating to the operation unit 14a, the control unit 14 drives the auxiliary power relay 22 to supply power to the control means 14 by the second power source 21. Is possible.

  After the power supply from the first power supply 20 to the control means 14 is interrupted, that is, after the latch relay 3 is turned off and the device is turned off, the second power supply 21 is continuously displayed by the control means 14. In the case where it is necessary to cool by detecting the temperature of the device or the temperature of the device, power is supplied to the control means 14.

  Further, the control means 14 can operate the open winding drive means 17 to turn off the latch relay 3, and the timer part 14e detects that the heating stop state continues or there is no input to the operation part for a predetermined time, The device can be turned off by operating the open winding driving means 17 and turning off the main power contact driving means 9.

  Even if the operation of the power switch 2 is continued and the contact is kept closed when the power source of the device is turned on, that is, when the latch relay 3 is turned on, the open holding means 19 and the open winding drive means. When the power is supplied to 17 and the open holding means 19 continues the off state of the device, the operation of the power switch 2 is continued when the latch relay 3 is off and the contact is kept closed. The off means 6 once drives the closed winding drive means 4 and then shuts off the power supply to the closed winding drive means 4 by the first switch element 5. Since the device can be turned off, the device can be reliably changed to the power-off state.

  Further, the forced-off means 19 is configured to output an operation command to the open-winding drive means 17 so that the latch relay 3 can be turned off, so that the power switch 2 can be continuously operated when the power of the device is turned off. Even if the closed state continues, the open winding driving means 17 is operated to turn off the latch relay 3, and the device can be reliably changed to the power-off state (claim 2).

  Further, the power switch 2 is connected in series with the closed winding driving means 4 and the first switching element 5, and when the contact of the power switch 2 changes from open to closed when the latch relay contact 3a is open, the first switch 2 is provided. When the switching element 5 is turned on and power is supplied to the closed-winding drive means 4, it is not necessary to always supply power to the open-winding drive means 4 when the power supply of the device is in the off state. Power consumption can be reduced (claim 3).

  Further, the latch relay contact 3a is connected in series with the open winding driving means 17 and the second rectifying element 18b, and when the latch relay contact 3a is closed, power supply to the open winding driving means 17 is enabled. The latch relay 3 can be turned off in accordance with a signal from the control means 14 or the forced-off means 6 (Claim 4).

  Further, the power switch 2 is connected in series with the open winding driving means 17 and the first rectifying element 18a, the power switch 2 is operated, the latch relay 3a is turned off, and the open winding driving means 17 via the latch relay contact 3a. Even when the power supply to is interrupted, power is supplied to the open winding drive means 17 via the contact of the power switch 2, and when the operation of the power switch 2 ends and the contact changes from closed to open, the winding is opened. Since the power supply to the line driving means 17 is cut off, the latch relay 3 can be reliably turned off, and the power consumed by the open winding driving means 17 when the power is turned off can be reduced. (Claim 5).

  The forced-off means 6 detects that the contact of the power switch 2 has changed from open to closed, and receives a signal from the contact detection means 8 that the latch relay contact 3a has changed from open to closed. Even if the latch relay contact 3a is opened after the switching element 5 is turned off, the first switching element 5 is kept off until the contact of the power switch 2 changes from closed to open. When the power switch 2 is continuously pressed in the power-off state and once changed to the power-on state and then returned to the power-off state, the device is configured not to change into the power-on state, thereby ensuring the safety of the device. (Claim 6).

  Further, the control means 14 includes a timer unit 14e capable of measuring time, the device maintains the power-on state for a predetermined time, and the user's operation is performed without performing the heating operation, the display notification operation, and the cooling operation. If it is detected that there is no power, the open winding drive means 17 is operated to change the power supply of the device to the OFF state, so that the user inadvertently forgets to turn off the power switch while leaving the device on. Even when notified by an erroneous operation, the power of the device can be turned off when a predetermined time has elapsed, and safety can be ensured by preventing erroneous operation and malfunction (claim 7).

  The latch relay 3 includes a large current relay 10 that supplies power to the heating unit 11, and the on / off operation of the large current relay 10 is linked with the on / off operation of the latch relay 3, thereby reducing the drive power required for the on / off operation. Since the power switch 2 for supplying power to the closed-winding drive means 5 and the open-winding drive means 17 can be used with a small contact capacity, it is possible to achieve downsizing and cost reduction. At the same time, since the power consumed by the closed-winding drive circuit 4 is small when the power supply of the device is turned on, the power supply quickly rises and drives the closed-winding, so that the response of the power switch 2 can be accelerated. ).

  In the first embodiment, the forced-off means 6 includes the time measuring means 7. However, the time measuring means 7 does not need to be a semiconductor having a possibility of runaway like a microcomputer, and is about 2 seconds. If it is possible to discriminate the time, it is desirable to configure the circuit with a low possibility of runaway although it cannot be accurately timed like an analog circuit.

  In the first embodiment, the main power contact driving means 9 is configured to be supplied with power when the latch relay 3 is turned on as a component of the contact detecting means 8, but the first power supply circuit 20 and the second power supply are provided. It goes without saying that the same effect can be obtained even if power is supplied from the circuit 21.

  As described above, the cooking device using the power switch without the lock mechanism according to the present invention realizes a reliable transition to the off state by shutting off the power supply to the closed winding drive circuit. Therefore, it can also be applied to applications such as a control system including a power switch that does not have a lock mechanism.

The block diagram of the heating cooker using the power switch which does not have the lock mechanism in Embodiment 1 of this invention. Block diagram of a heating cooker in Conventional Example 1 Block diagram of heating cooker in Conventional Example 2

Explanation of symbols

1 Commercial power supply 2 Power switch 3 Latch relay
4 Closed-winding drive means 6 Forced-off means 7 Timekeeping means 8 Contact detection means 9 Main power contact driving means 10 Main power relay 11 Heating part 12 Heating coil 13 Pot (object to be heated)
14 Control means 17 Open winding drive means 19 Open holding means 20 First power supply 21 Second power supply 22 Control power supply relay

Claims (8)

A power switch having no locking mechanism, a latch relay having a latching mechanism, a heating unit to which electric power is supplied when a contact of the latch relay is closed, a contact detection means for detecting a contact state of the latch relay, Closed winding drive means for closing the contact of the latch relay, open winding drive means for opening the contact of the latch relay, open holding means for keeping the contact of the latch relay open, and the contact of the latch relay closed Forcibly turning off the power supply to the closed winding drive means by detecting the state, and when the latch relay contact is closed, the power switch contact is closed and the latch relay contact is closed. When the switch contact is continuously closed after the switch changes from closed to open, the open holding means holds the latch relay contact in the open state, When the contact of the latch relay is open, the contact of the power switch is closed and the contact of the latch relay is changed from open to closed, and then the contact of the power switch is continuously closed. Is a heating cooker using a power switch that does not have a lock mechanism for performing control to shut off the power supply to the closed winding drive means and keep the contact of the latch relay in a closed state. The forced-off means includes a timing means, and when the contact of the power switch continues to be in the closed state even after the contact of the latch relay changes from open to closed, the forced-off means 2. The power switch having no lock mechanism according to claim 1, wherein the power supply to the closed winding driving means is cut off and the open winding driving means is operated to change the contact of the latch relay to the open state. There was a heating cooker. 3. When the contact of the latch relay is open, when the contact of the power switch is changed from open to closed, the power switch does not have the lock mechanism according to claim 1 or 2 for supplying electric power to the closed winding driving means. A cooking device that uses a power switch. The heating cooker using the power switch which does not have the lock mechanism according to any one of claims 1 to 3, wherein the contact of the latch relay supplies electric power to the open winding drive means in the closed state. When power is supplied to the open winding drive means, the contact of the power switch is changed from open to closed and the contact of the latch relay is opened. Then, when the power switch is changed from closed to open, the open winding drive means The heating cooker using the power switch which does not have the lock mechanism of any one of Claims 1-4 by which the electric power supply to is interrupted | blocked. If the contact of the power switch continues to be closed even after the contact of the latch relay is opened, the forced-off means continues to cut off the power to the closed winding drive means until the power switch contact is opened from the closed state. The heating cooker using the power switch which does not have the lock mechanism of any one of Claims 1-5. A control means capable of controlling the heating unit and measuring time is provided, and the control means is set so that the contact of the latch relay is kept closed for a predetermined time, the cooking device is not operated, and the state is changed. Heat cooking using a power switch that does not have a lock mechanism according to any one of claims 1 to 6, wherein control is performed to open a contact of the latch relay when the heating is not started (no heating is started by a timer). vessel. A power switch that does not have a lock mechanism according to any one of claims 1 to 7, further comprising a large current relay that supplies electric power to the heating unit, and the contact of the large current relay is interlocked with the contact of the latch relay. The cooking device used.