JP2008293763A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect ground connection at a normal time when a heating cooker is not in ground fault. <P>SOLUTION: The heating cooker has an outer frame 2 of which at least a part is a conductor, a heating part 3 which is connected to a commercial power supply 1, a Y capacitor (circuit impedance) 4 of which both terminals are connected to the commercial power supply 1, a connection means 5 to ground the outer frame, a functional ground 6 which is a connecting means of the other terminal of the circuit impedance 4 to the outer frame or to the connection means 5 to ground the outer frame 2, and a first ground current detection means 7 to detect the current flowing to the connection means 5 to ground the outer frame 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooking device such as an induction cooking device or an electric fish cooking device.

  Hereinafter, an example of a conventional cooking device will be described with reference to FIG.

  FIG. 3 is a diagram showing a circuit configuration of a conventional cooking device. The commercial power source 1 is grounded on one side and connected to the cooking device. The heating cooker has an outer shell 2 made of metal, and the outer shell 2 is grounded. The commercial power source is connected to the heating unit 3 via the zero-phase current transformer 11 and further via the opening / closing means 8. When the cooking is started, the opening / closing means 8 is closed, and a commercial power source is applied to the heating unit to heat and cook.

In the heating cooker configured as described above, when a ground fault occurs such as when the heating unit 3 has poor insulation, it is detected that an unbalanced current has occurred in the zero-phase current transformer 11 and a ground fault has occurred. 8 is opened and the heating part 3 which is a ground fault part is cut off to prevent electric shock even if the outer shell 2 is not grounded.
JP 2000-19211 A

  However, the conventional configuration has a problem that it is difficult to detect the ground connection in a normal state where there is no ground fault.

  This invention solves the said conventional subject, and it aims at providing the heating cooker which can carry out a ground connection detection at the normal time which is not ground-faulted by an easy structure.

  In order to solve the above-described conventional problems, a heating cooker according to the present invention includes an outer shell which is at least partially a conductor, a heating unit connected to a commercial power source, and a circuit in which both terminals are connected to the commercial power source. A functional ground which is a connection means between the impedance, a connection means for grounding the outline, a connection terminal for grounding the outline or the outline of the other terminal of the circuit impedance, and a ground for grounding the outline The first ground current detection means for detecting the current flowing through the connection means.

  With this configuration, it is possible to provide a heating cooker that can detect the ground connection at the normal time when there is no ground fault.

  The cooking device of the present invention can detect the ground connection at the normal time when there is no ground fault.

  According to a first aspect of the present invention, there is provided an outer shell which is at least partially a conductor, a heating unit connected to a commercial power source, a circuit impedance connected to both terminals of the commercial power source, and a connection means for grounding the outer shell. A functional ground that is a connecting means between the other terminal of the circuit impedance and the outer shell or a connecting means for grounding the outer shell, and a first ground that detects a current flowing through the connecting means for grounding the outer shell With the configuration including the current detection means, it is possible to detect the ground connection at the normal time when there is no ground fault.

  According to a second aspect of the present invention, there is provided an outer shell, at least a part of which is a conductor, a heating unit connected to a commercial power source, a circuit impedance connected to both terminals of the commercial power source, and a connection means for grounding the outer shell. And a functional ground that is a connecting means between the other terminal of the circuit impedance and the outer shell or a connecting means for grounding the outer shell, and a second ground current detecting means that detects a current flowing through the functional ground. By adopting the configuration, it is possible to more easily detect the ground connection at the normal time when there is no ground fault.

  In the third aspect of the invention, in particular, in the first or second aspect of the invention, the circuit impedance is a Y capacitor, so that it is possible to detect the ground connection in a normal state where there is no ground fault with an easy configuration.

  According to a fourth aspect of the present invention, in particular, in any one of the first to third aspects, at least one heating unit is an induction heating method, so that an earth connection can be detected in a normal state where there is no ground fault with an easy configuration. can do.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, if the current detected by the earth current detection means (first or second earth current detection means) is equal to or less than the first predetermined value. For example, the safety of the user can be ensured by adopting a configuration in which heating of the heating unit is stopped.

  In particular, the sixth invention includes any one of the first to fourth inventions, comprising an informing means, wherein the current detected by the earth current detecting means (first or second earth current detecting means) is the first. By adopting a configuration in which notification is made if the value is less than or equal to a predetermined value, the user can be alerted to unsafety.

  In a seventh aspect of the invention, in particular, in the fifth or sixth aspect of the invention, at least one heating unit is an induction heating method, and the first predetermined value is changed according to the induction heating frequency with an easy configuration. It is possible to detect the ground connection at the normal time when there is no ground fault.

  According to an eighth aspect of the invention, in particular, in any one of the fifth to seventh aspects, the heating unit stops heating if the current detected by the first ground current detection means is equal to or greater than a second predetermined value. By doing so, the safety of the user can be secured more.

  In particular, the ninth aspect of the present invention is the configuration according to any one of the fifth to seventh aspects of the present invention, further comprising a notification unit that notifies if the current detected by the first ground current detection unit is equal to or greater than a second predetermined value. By doing so, the safety of the user can be further ensured.

  In a tenth aspect of the invention, in particular, in the eighth or ninth aspect of the invention, the at least one heating unit is an induction heating method, and the second predetermined value detected by the first ground current detection means depends on the induction heating frequency. By changing the configuration, the ground connection can be detected in a normal state where there is no ground fault, and the safety of the user can be further ensured.

  In an eleventh aspect of the invention, in particular, in any one of the first to tenth aspects of the invention, the safety of the user can be further ensured by providing an opening / closing means for disconnecting the electrical connection between the commercial power source and the heating unit. can do.

  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)
FIG. 1 is a circuit configuration diagram of a heating cooker according to the first embodiment of the present invention.

  In FIG. 1, a commercial power source 1 is a 200V commercial power source, which is a single-phase two-wire system in this embodiment. The outer shell 2 is made of metal and is grounded by a lead wire which is a connection means 5 for grounding the outer shell. The commercial power source 1 is connected to an induction heating type heating unit composed of an inverter and a heating coil (not shown), and heats the pan placed facing the heating coil. Further, a heating unit 3, which is a sheathed heater, is connected to the commercial power source 1 via an opening / closing means 8. At the start of cooking, the opening / closing means 8 is closed and the heating unit 3 is energized to perform heating cooking. A Y capacitor having a circuit impedance 4 is connected to the commercial power source 1 for noise reduction, and the other end of the Y capacitor is connected to the outside by a functional earth 6. The connection means 5 for grounding the outer shell is provided with a first earth current detection means 7 comprising a current transformer.

  Since the current flows through the connecting means 5 for grounding the outer shell when grounded by the above configuration, the second earth current detecting means including the current transformer can detect the current flowing. Therefore, it can confirm that it is earth | grounded.

  However, no current flows through the connection means 5 for grounding the outer shell when it is not grounded due to inadequate construction or the like. Therefore, a first predetermined value is provided between the current value in the case of being grounded defined by the circuit impedance and the voltage of the commercial power supply and 0, and if it is less than the first predetermined value, heating is stopped and the opening / closing means is opened. It is separated as open, and the user is informed of the lack of grounding by a not-shown notification means to prevent a risk of electric shock.

  Further, when the heating unit 3 leaks to the outer shell due to poor insulation or the like, a leak current flows to the connecting means 5 for grounding the outer shell. When the current flowing through the connecting means 5 for grounding the outer shell is larger than the second predetermined value smaller than the leak current, the heating is stopped as the ground fault is abnormal, the opening / closing means is opened, and the notification is not shown. This means that the user is informed of the danger of grounding by means and prevents electric shock and fire hazard.

(Embodiment 2)
FIG. 2 is a circuit configuration diagram of the heating cooker according to the second embodiment of the present invention.

  In FIG. 2, the commercial power source 1 is a 200V commercial power source, and is a single-phase two-wire system in this embodiment. The outer shell 2 is made of metal and is grounded by a lead wire which is a connection means 5 for grounding the outer shell. The commercial power source 1 is connected to an induction heating type heating unit composed of an inverter and a heating coil (not shown), and heats the pan placed facing the heating coil. Further, a heating unit 3, which is a sheathed heater, is connected to the commercial power source 1 via an opening / closing means 8. At the start of cooking, the opening / closing means 8 is closed and the heating unit 3 is energized to perform heating cooking. A Y capacitor having a circuit impedance 4 is connected to the commercial power source 1 for noise reduction, and the other end of the Y capacitor is connected to a connection means 5 for grounding the outer shell by a functional earth 6. The functional earth 6 is provided with first earth current detecting means 7 comprising a current transformer.

  Since the current flows to the functional earth 6 when grounded by the above configuration, the first earth current detecting means including the current transformer can detect the current flowing. Therefore, it can confirm that it is earth | grounded.

  However, no current flows through the functional earth 6 when the earth is not grounded due to inadequate construction. Therefore, a first predetermined value is provided between the current value in the case of being grounded defined by the circuit impedance and the voltage of the commercial power supply and 0, and if it is less than the first predetermined value, heating is stopped and the opening / closing means It is separated as open, and the user is informed of the lack of grounding by a not-shown notification means to prevent a risk of electric shock.

  In the first and second embodiments, the single-phase two-wire system is used, but it goes without saying that the effects of the present invention can be obtained by other power distribution methods such as a single-phase three-wire system.

  In addition, the induction heating type may change the induction heating frequency depending on the load. In that case, the circuit impedance from the induction heating type heating unit changes the current flowing to the functional earth depending on the frequency. For example, the circuit impedance is Y capacitor In this case, the impedance decreases as the frequency increases, and the current flowing to the functional earth through the Y capacitor increases in accordance with the frequency. Therefore, the first predetermined value and the second predetermined value are increased in accordance with the frequency. Even when the circuit impedance is composed of other parts, the first predetermined value or the second predetermined value is changed according to the frequency by checking the change of the current flowing through the functional ground according to the frequency used in advance. Even if is changed, the desired operation is performed by changing the frequency according to the frequency to prevent an electric shock or a fire hazard.

  As described above, the cooking device according to the present invention can be operated even if it is systemized, so that it can be applied to uses such as a commercial combined cooking device.

The circuit block diagram of the heating cooker in the 1st Embodiment of this invention The circuit block diagram of the heating cooker in the 2nd Embodiment of this invention Circuit diagram of a conventional cooking device

Explanation of symbols

1 Commercial Power Supply 2 Outer 3 Heating Unit 4 Y Capacitor (Circuit Impedance)
5 Connection means for grounding the outer shell 6 Functional earth 7 First earth current detection means 8 Opening and closing means 9 Second earth current detection means

Claims (11)

At least a part of an outer shell made of a conductor, a heating unit connected to a commercial power source, a circuit impedance connected to both terminals of the commercial power source, a connection means for grounding the outer shell, and a circuit impedance A functional earth which is a connecting means between another terminal and the outer shell or a connecting means for grounding the outer shell; and a first earth current detecting means for detecting a current flowing through the connecting means for grounding the outer shell. A cooking device characterized by that. At least a part of an outer shell made of a conductor, a heating unit connected to a commercial power source, a circuit impedance connected to both terminals of the commercial power source, a connection means for grounding the outer shell, and a circuit impedance A functional ground which is a connecting means between another terminal and the outer shell or a connecting means for grounding the outer shell, and a second ground current detecting means which detects a current flowing through the functional ground. Cooking cooker. The cooking device according to claim 1 or 2, wherein the circuit impedance is a Y capacitor. The cooking device according to any one of claims 1 to 3, wherein at least one heating unit is an induction heating method. 5. The heating unit according to claim 1, wherein heating of the heating unit is stopped when the current detected by the ground current detection unit (first or second ground current detection unit) is equal to or less than a first predetermined value. 6. Cooking cooker. 5. The apparatus according to claim 1, further comprising: a notification unit that reports if the current detected by the ground current detection unit (first or second ground current detection unit) is equal to or less than a first predetermined value. Cooking cooker. The cooking device according to claim 5 or 6, wherein the at least one heating unit is an induction heating method, and the first predetermined value is changed according to the induction heating frequency. The cooking device according to any one of claims 5 to 7, wherein heating of the heating unit is stopped if the current detected by the first earth current detection means is equal to or greater than a second predetermined value. The heating cooker according to any one of claims 5 to 7, further comprising an informing means for informing if the current detected by the first earth current detecting means is equal to or greater than a second predetermined value. The heating according to claim 8 or 9, wherein the at least one heating unit is an induction heating method, and the second predetermined value detected by the first earth current detection means is changed according to the induction heating frequency. Cooking device. The cooking device according to any one of claims 1 to 10, further comprising opening / closing means for disconnecting electrical connection between the commercial power source and the heating unit.

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