KR200451186Y1 - Safety apparatus for heating cooker - Google Patents

Abstract

The present invention relates to a safety device for a heating cooker, and more particularly, to a safety device for a heating cooker to quickly cut off power for heating when abnormal overheating is caused in the heating cooker.

The safety device of the heating cooker according to the present invention includes a heating part for supplying heat to the inner pot of the cooking device, a rectifying part for rectifying a commercial AC voltage and supplying a DC voltage, and a voltage corresponding to the temperature or temperature of the inner pot of the cooking device. A temperature sensing unit for detecting a value, a switching element for supplying or interrupting a DC voltage from the rectifying unit, and a control signal for supplying and interrupting a DC voltage are generated and applied to the switching element, thereby providing general cooking. The microcomputer performs the process, and a blocking unit which blocks the control signal applied from the microcomputer to the switching element according to the sensed temperature or the magnitude of the voltage value, and cuts off the supply of the DC voltage to the heating unit, and interlocks with the operation of the blocking unit. Including a reset unit for initializing the microcomputer to the standby state, the protection of the microcomputer and the elements such as the heating unit can be quickly performed. All.

Description

SAFETY APPARATUS FOR HEATING COOKER}

The present invention relates to a safety device for a heating cooker, and more particularly, to a safety device for a heating cooker to quickly cut off power for heating when abnormal overheating is caused in the heating cooker.

A general heating cooking apparatus includes a main body, a cooking container mounted on the inside of the main body to hold food, and a cooking heater (or induction coil) mounted on the lower part of the cooking container or inside the main body to cook food contained in the cooking container. Consists of

Such a cooking appliance is a home appliance that cooks food by heating the food at a predetermined level or more by containing the food contained therein, and in the present specification, a current flows in coils formed at predetermined intervals in a main body portion on which the cooking vessel is seated. Due to the magnetic field generated according to the present invention, an induction heating cooking apparatus of a method in which an eddy current is generated in a cooking vessel made of a magnetic material to heat the cooking vessel will be described.

In one embodiment of the induction heating cooker, the electric pressure cooker (or electric pressure thermal cooker) is programmed to proceed the cooking process to the specified control temperature in the cooking algorithm, the reading by reading the sensor temperature value located in the rice cooker in the microcomputer Each process of the algorithm is controlled to cook.

In addition, the electric pressure cooker has a pressure holding valve (for example, a pressure valve) for maintaining a constant pressure during cooking and a steam discharge valve (for example, a solenoid valve) for discharging steam after cooking.

Therefore, in order to cook rice in a short time due to the nature of the pressure cooker requires a high output (calorie of heat of IH heat source), so it is accompanied by risk factors such as high voltage, high current, high heat, high pressure pressure. In order to secure customers' safety from these risks, the electric pressure cooker has been installed with more than 10 safety devices (including appliances and electric safety devices).

1 is a block diagram of a safety device of an induction heating cooker according to the prior art.

As shown in FIG. 1, the safety device 1 of an induction heating cooking device includes a power supply unit 11 that receives and supplies an external power source (commercial AC power supply), and a rectifying unit 12 rectifying and smoothing the external power source to a DC voltage. ), A fuse 13 for blocking the application of the external power supply to the power supply 11, and a resonator 20 configured to perform heating by receiving the resonance voltage generated by the switching operation of the DC voltage by the switching element 30. ), The IGBT driver and the oscillator 14 generating and applying a driving pulse for controlling the switching operation (on / off) of the switching element 30, and the on / off according to the driving pulses from the IGBT driver and the oscillator 14. The switching device 30 is configured to perform a switching operation of the DC voltage by turning off, and the induction heating command is transmitted to the IGBT driver and the oscillator 14, and the MICOM unit 40 is configured to induce heating.

The power supply unit 11 receives a commercial AC power from the outside and applies it to the rectifier 12. In addition, the rectifier 12 is a device for rectifying and smoothing a commercial AC power supply with a DC voltage, and may include a rectifying circuit having a diode bridge type and a smoothing circuit including a capacitor.

The fuse 13 is attached to, for example, the inner pot, so that an external power source is normally applied to the power supply unit 11, but when abnormal overheating occurs, the internal circuit is short-circuited and the entire external power source is an electric pressure cooker. Supply to is cut off.

In addition, the IGBT driver and the oscillator 14 apply a driving pulse of a pre-stored form (that is, a waveform having a pre-stored duty ratio) according to the induction heating command from the MICOM unit 40 to the switching element 30. In addition, the IGBT driver and the oscillator 14 maintain or vary the duty ratio of the driving pulses according to the cooking process, and apply the driving pulses to the switching element 30.

The switching element 30 is an IGBT element that is turned on / off by a signal (for example, a driving pulse, etc.) applied through the gate terminal. The switching element 30 uses a gate terminal and an emitter to stabilize the driving pulse flowing into the gate terminal. A resistor (R) is installed between the terminals to stabilize the bias.

However, such a conventional safety device is a protective measure when the microcomputer is in a normal condition, and the microcomputer malfunctions due to unexpected internal and external disturbances (for example, noise component, instantaneous power failure, misuse of the customer, etc.). It was difficult to respond safely and accurately except for the method of shutting off the power by a fuse.

As described above, even if the application of the external power is blocked by the fuse of the final stage that detects the abnormal overheating, even if safety is ensured, a part of the induction heating cooker is sometimes lost (mechanical deformation).

Accordingly, an object of the present invention is to provide a safety device for a heating cooker that can protect a microcomputer and a heating unit (heater, IH coil, etc.) from internal and external factors.

In addition, an object of the present invention is to provide a safety device for a heating cooker, such that when abnormal overheating due to internal and external factors occurs, the power supply to the heating unit is quickly and reliably shut off.

In addition, an object of the present invention is to provide a safety device for a heating cooker that can quickly display the initialization of the microcomputer due to internal and external factors to the user.

The safety device of the heating cooker according to the present invention includes a heating part for supplying heat to the inner pot of the cooking device, a rectifying part for rectifying commercial AC voltage and supplying a DC voltage, and a voltage corresponding to the temperature or temperature of the inner pot of the cooking device. A temperature sensing unit for sensing a value, a switching element for supplying or interrupting a DC voltage from the rectifying unit, and a control signal for supplying and interrupting the DC voltage are generated and applied to the switching element, thereby providing general cooking. The microcomputer performs the process, and a blocking unit which blocks the control signal applied from the microcomputer to the switching element according to the sensed temperature or the magnitude of the voltage value, and cuts off the supply of the DC voltage to the heating unit, and interlocks with the operation of the blocking unit. Including a reset unit for initializing the microcomputer to the standby state, protection of the microcomputer and the heating unit and the like is performed quickly. The.

In addition, the reset unit includes a reset circuit unit for generating a reset signal and applying it to the microcomputer, and a forced reset unit operated by the breaker unit to cause the reset circuit unit to generate a reset signal, and the safety device corresponds to driving of the breaker unit or initialization of the microcomputer. It is provided with a display unit for visually or audibly notifying the notification message, the initialization operation for the microcomputer and the information accordingly to promptly inform the user.

In addition, when the sensed temperature or voltage value is equal to or greater than the first reference value, the cut-off unit may generate an output signal from the microcomputer to the switching element by an abnormal temperature comparison unit that generates an output signal and an output signal of the abnormal temperature comparison unit. An output breaker for bypassing the control signal is bypassed, and a latch circuit portion for holding the output signal between the abnormal temperature comparator and the output breaker to quickly and accurately determine the occurrence of the abnormal state.

In addition, the reset unit operates by obtaining an output signal from the latch circuit unit.

The safety device also includes a voltage dividing unit for dividing the temperature or voltage value from the temperature sensing unit and applying it to the cut-off unit.

In addition, the heating unit is a resonant circuit, the microcomputer includes a switching control unit for generating a control signal, which is a driving pulse for the on / off operation of the switching element, and applying it to the switching element, and the microcomputer controls the switching control unit so that the switching element is driven. By applying a resonant voltage to the heating unit by switching the DC voltage according to the control signal which is a pulse, the present invention can be applied to the induction heating cooking apparatus.

In addition, the heating unit is a hot plate, the microcomputer generates a control signal for the on / off operation of the switching element so that the switching element is supplied to and cut off the DC voltage to the heating unit according to the control signal, the present invention is a hot plate type heating cooker Can be applied to

Accordingly, the present invention protects devices such as microcomputers and heating units from internal and external factors, thereby ensuring the safety of users and products.

In addition, the present invention has an effect that the power to the heating unit is quickly and reliably cut off when abnormal overheating occurs due to internal and external factors.

In addition, the present invention has an effect of promptly displaying the initialization of the microcomputer due to internal and external factors to the user, so that the user can be quickly notified and repaired.

In addition, the present invention has the effect of preventing the overheating phenomenon or to cope quickly, to ensure the safety of the user from the safety hazards (control element damage, thermal changes of the structure, electric shock, etc.).

Hereinafter, the present invention is described in detail based on the embodiments of the present invention and the accompanying drawings.

In the present specification, as an embodiment of a heating cooker, an electric pressure cooker (or an electric pressure heat cooker) is described.

Electric pressure cooker is a cooking utensil for cooking food that is hard to be boiled at normal pressure in a short time by raising the pressure in the pot by heating the pot in a closed space by a heater or IH coil.

In general, electric pressure cooker is the inner pot is accommodated in the body, cooked food is accommodated in the inner pot is cooked, the outer lid and inner pot lid is installed to open and close the inner pot to cover the body and the inner pot to open and close, the inner pot is Cooking is performed while being heated by various IH coils or heaters (hot plates) built into the main body.

2 is a block diagram of a first embodiment of a safety device of a heating cooker according to the present invention.

As shown in FIG. 2, the safety device of the heating cooker includes a power supply unit 11 for receiving and supplying a commercial AC power supply, a rectifier 12 rectifying and smoothing the commercial AC power with a DC voltage, and a switching device 30. Resonator 20, which is a heating unit that receives the resonance voltage by the DC voltage switching operation, and generates and applies a driving pulse for controlling the switching operation (on / off) of the switching element 30. To the IGBT driver and the oscillator 14, the switching element 30 to switch the DC voltage on and off according to the driving pulses from the IGBT driver and the oscillator 14, and the IGBT driver and the oscillator 14. By sending an induction heating command, the MICOM unit 50 for induction heating, a temperature sensor 52 for detecting a temperature value corresponding to the temperature or temperature of the inner pot of the induction heating cooking apparatus, and the detected inner pot Corresponding to temperature or temperature The abnormal temperature comparison unit 54 for comparing the voltage value with the first reference value and generating an output signal according thereto, the latch circuit unit 56 for holding the output signal of the abnormal temperature comparison unit 54, and the output signal. An output interrupter 58 for interrupting the drive pulse from the IGBT driver and the oscillator 14 to the switching element 30, a forced reset unit 62 for operating the reset circuit unit 64 in accordance with the output signal, and a forced reset unit It consists of a reset circuit section 64 operated by 62 to initialize the MICOM section 50. The first embodiment relates to a cooking appliance according to an induction heating method in a heating cooking appliance.

Here, the power supply unit 11 is applied from the outside as a commercial AC power supply to the rectifier 12. In addition, the rectifier 12 is a device for rectifying and smoothing a commercial AC power supply with a DC voltage, and may include a rectifying circuit having a diode bridge type and a smoothing circuit including a capacitor. Of course, the DC voltage through the power supply unit 11 and the rectifying unit 12 is supplied not only to the resonator unit 20, but also to other component elements requiring a DC voltage, and the supply is provided to those skilled in the art. It is just an easy technique.

In addition, the IGBT driver and the oscillator 14 apply a driving pulse of a pre-stored form (that is, a waveform having a pre-stored duty ratio) according to the induction heating command from the MICOM unit 40 to the switching element 30. In addition, the IGBT driver and the oscillator 14 maintain or vary the duty ratio (that is, the ratio between the HIGH signal section and the LOW signal section) of the driving pulses applied according to the progress of the cooking process, and switch the driving pulses accordingly. To the device 30.

The resonator 20, which is a heating unit, performs a cooking function by a method in which an eddy current flows when the magnetic force line generated by the working coil 21 passes through the inner pot, thereby heating the pot itself. That is, when a current is applied to the working coil 21, the inner pot (or oven), which is a magnetic material, is heated by induction heating, and cooking within the inner pot is performed. Therefore, in the case of an induction heating cooker, when a high frequency voltage having a predetermined magnitude is applied to the working coil 21 to generate magnetic lines, strong heat is generated in the inner pot. The resonator 20 corresponds to a resonant circuit composed of the wicking coil 21 and the capacitor C.

The switching element 30 uses an IGBT element that is turned on / off by a signal (for example, a driving pulse) applied through the gate terminal.

The MICOM unit 50 receives the cooking or cooking command from the user, generates an induction heating command according to a cooking algorithm corresponding thereto, and applies the cooking command to the IGBT driver and the oscillator 14. The MICOM unit 50 controls and performs the entire cooking process. The MICOM unit 50 may be configured together with the IGBT driver and the oscillator 14 or may be separately configured, or may be collectively referred to as the MICOM unit.

In addition, the temperature detector 52 detects a voltage value corresponding to the temperature or temperature of the inner pot of the induction heating cooker. Induction heating cooker (including IH electric pressure cooker), in addition to the resonator 20 formed near the bottom or bottom of the inner pot, and includes a separate heater (upper, side) sensor (temperature input) to detect these heat sources It detects the internal temperature and outputs a voltage value in proportion to the temperature and receives the input from the MICOM unit 50 to perform the cooking process. Since the heating influence through the resonator 20 is greater than that of other heaters, the MICOM unit 50 performs the entire cooking process on the basis of the inner pot temperature (lower or bottom temperature of the inner pot) corresponding to the resonator 20. In the present invention, the temperature sensing unit 52 is also a serious problem because the abnormal heating in the resonator 20, the thermostat (TH) located on the bottom of the inner pot is heated by the resonator 20 It should be recognized to include. In addition, although omitted in FIG. 2, the voltage value corresponding to the temperature or the temperature by the temperature sensing unit 52 is applied to the MICOM unit 50, and the MICOM unit 50 uses the temperature information in the cooking process.

In addition, the temperature sensing unit 52 includes a voltage dividing resistor unit consisting of resistors R1 and R2, so that the temperature in the temperature sensing unit 52 or the voltage value corresponding to the temperature is reduced by the partial pressure ratio to compare the abnormal temperature. To be applied to the section 54, and a cutoff section (abnormal temperature comparison section 54, latch circuit section 56, output cutout section 58) and reset section (forced reset section 62, reset circuit section 64). To be protected. The supply resistance Vcc is applied to the voltage dividing resistor so that voltages from the supply potential Vcc and the thermostat TH are applied to the abnormal temperature comparison unit 54.

In addition, the blocking unit (the abnormal temperature comparing unit 54, the latch circuit unit 56, and the output blocking unit 58) may include a voltage value (or a divided voltage value) corresponding to the temperature or the temperature detected by the temperature sensing unit 52. In accordance with the magnitude of?), When abnormal overheating occurs (or abnormal high temperature close to abnormal overheating occurs), the driving pulse from the IGBT driver and the oscillator 14 to the switching element 30 is bypassed. The blocking unit protects the switching element 30, which is an IGBT (high frequency switching element) for controlling the resonator 20, which is a heat source of the induction heating cooker, or blocks overheating of the resonator 20.

In addition, the abnormal temperature comparator 54 is applied with the temperature or voltage value from the temperature sensor 52 divided by an inverting terminal, and the voltage magnitude (or abnormal overheating) occurs when abnormal overheating occurs with the non-inverting terminal. It includes a comparator (CP1) (OP AMP) to which the reference potential (Vref1) corresponding to a predetermined magnitude lower than that of the case is applied. The reference potential Vref1 is a potential indicating the temperature of the inner pot or a voltage value corresponding to the temperature when abnormal overheating occurs. The abnormal temperature comparison unit 54 generates an output signal when the temperature or voltage is equal to or higher than the reference potential Vref1.

The diode D1 blocks the input of the latch circuit section 56 to the non-inverting terminal from being applied to the output terminal of the abnormal temperature comparison section 54.

The latch circuit 56 receives the output signal from the diode D1 and the output of the comparator CP2 as a non-inverting terminal, and the inverting terminal has a reference potential Vref2 when abnormal overheating occurs (or abnormal overheating occurs). It is a value corresponding to the voltage level of a certain magnitude lower than that when it occurs, or the output of the abnormal temperature comparison unit 54 at this time. The output of the comparator CP2 is connected to the non-inverting terminal through the diode D2. The latch circuit section 56 applies the output signal to the output interrupting section 58 while maintaining the output signal from the abnormal comparison circuit section 54.

In addition, the output blocking unit 58 is turned on / off by the output signal from the latch circuit unit 56. The output terminal from the latch circuit portion 56 is applied to the base terminal of the transistor Q1 of the output interrupter 58, the emitter terminal is grounded, and the collector terminal is the IGBT driver and the oscillator 14 and the switching element 30. ) Is connected between. Accordingly, the output blocking unit 58 is turned on by the output signal from the latch circuit unit 56 to bypass the driving pulses of the IGBT driving unit and the oscillating unit 14 to block the input of the driving pulse to the switching element 30. do. As a result, the application of the DC voltage to the driver 20 is blocked.

In addition, the reset section (forced reset section 62, reset circuit section 64) operates on the output signal from the interruption section so that the MICOM section 50 is initialized to the standby state. In general, the MICOM unit 50 has a function for resetting, and by the initialization to the standby state, the MICOM unit 50 corresponds to the termination of the induction heating command to the IGBT driver and the oscillation unit 14, The heating cooker is supplied with an external power source, and does not operate any function related to cooking. Such an initialization may be caused by various overheating elements such as the resonator 20, the switching element 30, and the MICOM unit 50 of the induction heating cooker when the abnormal overheat occurs. Cooking is not performed so that the user's protection and other elements can be protected.

The forced reset part 62 of the reset part has a transistor having an emitter terminal grounded, a base terminal connected to a blocking part (exactly, an output terminal of the latch circuit part 56), and a collector terminal connected to the reset circuit part 64 ( Q2). The forced reset section 62 is turned on by the output signal from the latch circuit section 56, and causes the reset circuit section 64 to operate.

The reset circuit section 64 operates by the ON operation of the forced reset section 62 to generate a reset signal and apply the reset signal to the MICOM section 50 so that the MICOM section 50 is initialized to the standby state.

In addition, the induction heating cooking apparatus performs an input unit 72 for obtaining an input such as a menu selection from a user, a display of a cookable menu, a display of a menu selected by the user, a display of a current state of the induction heating cooker, and the like. The display part 74 is provided. The MICOM unit 50 acquires a user input from the input unit 72, performs a control corresponding to the same, and allows the display unit 74 to perform the above-described display.

In particular, when the MICOM unit 50 receives the reset signal from the reset unit or is initialized by the reset signal, the MICOM unit 50 displays such a state through the display unit 74, so that the user has a problem such as abnormal overheating. It is to inform that the MICOM unit 50 has been initialized. Here, the display unit 74 is provided with display means or alarm means for visually or audibly displaying the initialization state of the MICOM unit 50.

3 is a process graph in which an operation by the safety device of FIG. 2 is performed.

The process of operating the safety device of the induction heating cooking appliance according to the present invention is described.

First, the MICOM unit 50 performs a standby process in a state where power is applied. When the cooking command is received through the input unit 72 during this waiting process, an induction heating command according to the cooking algorithm corresponding thereto is generated and applied to the IGBT driver and the oscillator 14. According to the induction heating command, the IGBT driver and the oscillator 14 supply the driving pulse to the gate terminal of the switching element 30, and the switching element 30 is turned on during the HIGH signal period of the driving pulse, thereby switching element. Current is conducted between the collector terminal and the emitter terminal of (30). During this HIGH signal period, current flows through the coil 21 of the resonator 20, so that electromagnetic energy is accumulated in the coil 21, and a part of the accumulated electromagnetic energy is used for induction heating of the inner pot.

Next, during the LOW signal period of the drive pulse, the switching element 30 is turned off so that no current flows between the collector terminal and the emitter terminal. On the other hand, the electromagnetic energy accumulated in the coil 21 charges the capacitor C, thereby raising the voltage of the collector terminal of the switching element 30. Subsequently, when the electromagnetic energy accumulated in the coil 21 is exhausted, the current flow from the coil 21 to the capacitor C ends, and at this point, the voltage charged in the capacitor C (for example, at most 1,100 V). ) Is the maximum. In particular, the charging voltage increases in proportion to the magnitude of the DC voltage from the rectifier 12 and the width of the HIGH signal section of the driving pulse. At this point, the electric energy charged in the capacitor C is discharged, and a current flows through the coil 21 in the reverse direction, whereby electromagnetic energy is accumulated in the coil 21, and a part of the accumulated electromagnetic energy is cooked. Induction heating of the instrument. The discharge of the capacitor C lowers the voltage at the collector terminal of the switching element 30. When the resonance of the coil 21 and the capacitor C occurs, and the voltage of the collector terminal of the switching element 30 drops to 0 V, the IGBT driver and the oscillator 14 apply the driving pulse to the switching element 30 again. Thus, induction heating is made continuously.

Through this process, a soaking process, a primary heating process, a secondary heating process, and a moxibustion process are performed, and the normal cooking process represents a control temperature and a temperature distribution of the inner pot as a normal heating pattern (solid line graph). During the progress of the normal heating pattern, the temperature is distributed below the critical temperature T1, which is the inner pot temperature when abnormal overheating occurs.

However, if the temperature of the inner pot is equal to or higher than the threshold temperature T1 in any process, such as an abnormal heating pattern (dotted graph) during the cooking process, the cut-off portion may have a temperature value corresponding to the temperature or temperature from the temperature sensing unit 52. By performing the blocking operation by the size, the driving pulses from the IGBT driver and the oscillator 14 are blocked by the bypass. In addition, the reset unit operates by the output signal of the interrupting unit, and the MICOM unit 50 is initialized, and the reset control is performed so that the control temperature is controlled like the temperature of the standby state. By this control, the temperature of the inner pot is gradually lowered, and this process is clearly shown as the abnormal heating pattern is gradually lowered by the reset control. However, due to the accumulated energy in the resonator 20, the temperature does not immediately drop even after the reset control is performed, but the temperature rises for a predetermined time, and when the accumulated energy is consumed, the temperature gradually decreases.

The MICOM unit 50 continuously maintains the initialization state, and may display the initialization state or the occurrence of abnormal overheating through the display unit 74. By this display, the user may recognize a failure of the induction heating cooker, and the repair of the induction heating cooker may be performed through a service center or the like.

Figure 4 is a block diagram of a second embodiment of a safety device of a heating cooking appliance according to the present invention. The safety device of the heating cooking apparatus includes a power supply unit 11 for receiving and supplying a commercial AC power supply, a rectifying unit 12 for rectifying and smoothing the commercial AC power with a DC voltage, and a switching operation by a relay 31. The MICOM unit which controls the overall cooking process by generating and applying a heater (hot plate) 22, which is a heating unit for receiving heating, and a driving pulse for controlling the switching operation (on / off) of the relay 31 ( 51, the temperature sensing section 52, the abnormal temperature comparing section 54, the latch circuit section 56, and the drive pulse from the MICOM section 51 to the transistor Q3 and the relay 31 in accordance with the output signal. An output interrupter 58 for interrupting the circuit, a forced reset part 62, a reset circuit part 64 operated by the forced reset part 62 to initialize the MICOM part 51, an input part 72, and a display part. It consists of 74. The second embodiment relates to a cooking appliance according to a heater type or a hot plate type heating type among heating cookers.

Here, the power supply unit 11 is applied from the outside as a commercial AC power supply to the rectifier 12. In addition, the rectifier 12 is a device for rectifying and smoothing a commercial AC power supply with a DC voltage, and may include a rectifying circuit having a diode bridge type and a smoothing circuit including a capacitor. Of course, the DC voltage through the power supply unit 11 and the rectifying unit 12 is supplied not only to the heater 22, which is a heating unit, but also to other components that require a DC voltage, and this supply is familiar to the technical field to which the present invention belongs. It's just an easy technique for people.

The heater 22, which is a heating unit, receives a DC voltage from the rectifying unit 12, but is supplied and cut off by the relay 31, which is a switching element, to perform a heat generation operation accordingly. The heater 22 may be centrally formed on the bottom of the inner pot, but may include side heaters and upper heaters separately.

The relay 31, which is a switching element, receives the supply voltage Vcc through the resistor R3, the diode D3 is connected in parallel, and the capacitor C1 is connected to one end of the relay 31. In addition, the relay 31 is connected to the collector terminal of the transistor Q3, the MICOM unit 51 and the output blocking unit 58 are connected to the base terminal of the transistor Q3, and the emitter terminal of the transistor Q3. Is grounded. In the present invention, the relay 31 and the transistor Q3 may be collectively referred to as a switching element. In addition, the relay 31 is replaceable with an element such as a triac, and the like, and the switching element includes an element having such a switching function.

Basically, the MICOM unit 51 applies a control signal such as a driving pulse to the transistor Q3, and when the HIGH signal is applied, the transistor Q3 is turned on, and the relay 31 operates so that the DC voltage is applied. It is applied to the heater 22, and a heat generation operation is performed. On the contrary, when the LOW signal is applied, the transistor Q3 is turned off, the relay 31 is turned off, and the heat generation operation is stopped.

The functions of the power supply unit 11, the rectifying unit 12, the heater 22, the relay 31 as a switching element, the transistor Q3, and the MICOM unit 51 described above are the operations of a general hot plate type heating cooker. Corresponds to.

The safety device according to the present invention is additionally provided with the blocking unit and the reset unit described above with reference to FIGS. 2 and 3 to perform a corresponding operation effect.

The temperature sensing unit 52 of the blocking unit is located on the bottom of the inner pot, and performs the same function as the temperature sensing unit 52 corresponding to FIG. 2. In addition, the abnormal temperature comparison section 54 and the latch circuit section 56 also perform the same function as described above, except that the output blocking section 58 is provided between the MICOM section 51 and the transistor Q3 which is a switching element. Connected to block the driving pulses from the MICOM unit 51 to the transistor Q3 and the relay 31 in accordance with the output signal from the latch circuit unit 56. Since the output blocking unit 58 forcibly blocks the operation of the control signal from the MICOM unit 51 from being performed, it may be connected between the transistor Q3 and the relay 31.

In addition, the forced reset unit 62 and the reset circuit unit 64 initialize the MICOM unit 51 to the standby state in conjunction with the operation of the breaker, as shown in FIGS. To be protected.

The interruption and reset operations of the power supply are known to the user visually or audibly through the display unit 74.

The safety device of the heating cooker of FIG. 4 described above basically performs cooking by a hot plate, and may be applied to, for example, an electric pressure thermal cooker, and when such an abnormality occurs as illustrated in FIG. It blocks the operation and resets the micom.

In the above, the present invention has been described in detail based on the embodiments of the present invention and the accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, the scope of the present invention will be limited only by the contents described in the utility model registration claims described below.

1 is a block diagram of a safety device of an induction heating cooker according to the prior art.

2 is a block diagram of a first embodiment of a safety device of a heating cooker according to the present invention.

3 is a process graph in which an operation by the safety device of FIG. 2 is performed.

Figure 4 is a block diagram of a second embodiment of a safety device of a heating cooking appliance according to the present invention.

Claims (7)

A heating unit configured to supply heat to the inner pot in which the cooking object is accommodated; A rectifier for rectifying the commercial AC voltage and supplying a DC voltage; A temperature sensor detecting a voltage value corresponding to the temperature or temperature of the inner pot of the cooking appliance; A switching element for causing a DC voltage from the rectifying portion to be supplied or cut off to the heating portion; A microcomputer generating a control signal for supplying and blocking a DC voltage and applying the same to a switching device to perform an overall cooking process; A blocking unit which blocks a control signal applied from the microcomputer to the switching element according to the sensed temperature or the magnitude of the voltage value from the temperature sensing unit, and cuts off the supply of the DC voltage to the heating unit; And a reset unit for initializing the microcomputer to the standby state in association with the operation of the blocking unit. The method of claim 1, The reset section includes a reset circuit section for generating a reset signal and applying it to the microcomputer, and a forced reset section operated by the shutoff section to cause the reset circuit section to generate a reset signal. Safety device for a heating cooker characterized in that it comprises a display for visually or audibly notifying the message. The method of claim 1, If the detected temperature or voltage value is equal to or greater than the first reference value, the cut-off unit controls the control signal from the microcomputer to the switching element by an abnormal temperature comparison unit generating an output signal and an output signal of the abnormal temperature comparison unit. And a latch circuit unit for holding an output signal between the abnormal temperature comparing unit and the output blocking unit. The method of claim 3, And the reset unit operates by obtaining an output signal from the latch circuit unit. The method of claim 1, The safety device is a safety device of a heating cooker comprising a voltage divider for dividing the temperature or voltage value from the temperature sensing unit to apply to the cut-off unit. The method according to any one of claims 1 to 5, The heating part is a resonant circuit, The microcomputer includes a switching control unit which generates a control signal which is a driving pulse for the on / off operation of the switching element and applies it to the switching element. Safety device for a heating cooker, characterized in that for switching to apply a resonant voltage to the heating unit. The method according to any one of claims 1 to 5, The heating part is a hot plate, The microcomputer generates a control signal for the on / off operation of the switching device, so that the switching device supplies and cuts the DC voltage to the heating unit according to the control signal.

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