JP2019216014A - Heating cooker - Google Patents

Abstract

To detect a defect of an adjustment deviation of a door switch having a plurality of generation rates of the defect in all the lifetime.SOLUTION: A heating cooker comprises: a plurality of heating means of heating a heated material; input means 12 of selecting the heating means; a door switch 10 that controls a selection of each heating means and is operated in association with an open and close of a door of controlling an electric conduction to each heating means; switching means 9 of controlling an electric conduction to each heating means; controlling means 2 of controlling the electric conduction by controlling the switching means 9 to select each heating means; and current detection means 8 of detecting an electric conduction current at the operation of each heating means. The control means 2 tries to perform the electric conduction by changing the selected heating means to the other alternate heating means when detecting a detection value of a near zero in the current detection means 8 after the starting of heating of the heated heating material, and stops the heating as a defect of the door switch 10 in the case where there is no change in the detection value of the current detection means 8.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cooking device, and more particularly, to a cooking device suitable for detecting an adjustment failure of a door switch of the cooking device.

  2. Description of the Related Art A heating cooker such as a high-frequency heating cooker is provided with many safety devices to prevent microwaves oscillated from a magnetron from leaking from a main body when an object to be heated is heated.

  Particularly, as a structure for preventing microwave leakage from a gap between a closed door and a main body during heating, a shield structure for attenuating microwaves leaking from the gap is provided on the door side.

  In addition, when the door is opened during heating, the structure that stops the transmission of the magnetron early and safely before the microwave leaks beyond the ability of the shield structure provided on the door side, drives the magnetron when the door is opened A mechanism for shutting off the power supply is provided so as to operate in conjunction with a door opening / closing mechanism.

  One of the mechanisms for shutting off the power supply for driving the magnetron is to open a power supply line when a door is opened by a door switch that opens and closes contacts in a structural manner in conjunction with opening and closing of the door. One is to close the contacts when the door is opened with a monitor switch that operates in the opposite direction to the opening and closing of the contacts of the door switch when the door is opened and closed. In this case, the power supply line is opened by short-circuiting the power supply line and blowing the current fuse in series with the power supply. One is a control door switch that opens and closes in a structurally interlocked manner with the opening and closing of the door. When the door is opened, the opening of the control door switch is detected, and the control unit turns off the power opening / closing means that controls the operation of the magnetron. Alternatively, it is opened to open the power supply line.

  On the other hand, there is known a technique of detecting a current at the time of heating to detect a failure of a functional component of the cooking device, and judging that a power relay is not operating when no current flows. Such a technique is described in, for example, Japanese Patent Application Laid-Open No. 2-56891 (Patent Document 1).

JP-A-2-56891

  It is very difficult to adjust the operation timing of each of the above-described switches that operate in conjunction with the opening and closing of the door. On the other hand, when the door is opened, if there is a large margin in the timing of starting the opening operation of the door switch, there is a problem that the gap between the doors becomes large before the door switch is operated, and microwave leakage becomes large.

  In a heating cooker, it is necessary to adjust a door switch so as not to cause the above-described problem due to thermal expansion while minimizing radio wave leakage.

  The width of the adjustment of each of the switches described above is very small, and in the lifetime use of the product, there are many problems caused by the adjustment deviation during use due to the failure of the switches and the electronic components described above.

  The high-frequency heating device disclosed in Patent Literature 1 detects a current during heating, and determines that the power relay is not operating when no current flows.

  In the high-frequency heating device disclosed in Patent Document 1, the influence of the thermal expansion of the door and the main body described above is not considered. For this reason, there is a problem that the failure mode in which the object to be heated is not heated due to the misalignment of the door switch during heating is not considered.

  The present invention has been made to solve the above problems, and includes a plurality of heating means for heating an object to be heated, an opening / closing means for controlling energization to the heating means, and controlling the opening / closing means. Control means for selecting the heating means to control energization, a door switch operable to control energization to the heating means in conjunction with opening and closing of a door, and an energizing current supplied to the heating means. Current detection means for detecting, the control means, when the detected value of the current detection means after the start of heating of the object to be heated is a value which does not correspond to the operation of the heating means, the selected heating means Is changed to another alternative heating means, an attempt is made to energize, and if the value detected by the current detection means maintains a value not corresponding to the operation of the heating means, it is determined that the door switch is defective.

  Alternatively, a plurality of heating means for heating the object to be heated, an input means for selecting the heating means, a door switch for controlling energization of the heating means and operating in conjunction with opening and closing of a door, Opening and closing means for controlling the energization of the control means for controlling the energization by selecting the heating means by controlling the opening and closing means, and a current detection means for detecting an energizing current when the heating means is operated, The control means, when the detection value of the current detection means detects substantially zero after the start of heating of the object to be heated, changes the selected heating means to another alternative heating means and attempts to energize, If there is no change in the detection value of the current detection means, the heating is stopped as a malfunction of the door switch.

  ADVANTAGE OF THE INVENTION According to this invention, the misalignment of the door switch which has a high incidence of malfunctions during the lifetime use of the cooking device can be detected.

External view of a microwave oven according to an embodiment of the present invention Main circuit block diagram of the present invention Explanatory drawing of a circuit showing a main part of the present invention

  An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a diagram showing an overall external view. A microwave oven 14 as a heating cooker according to the present invention includes a housing 16 surrounding an upper surface, a lower surface, a back surface, a right side surface and a left side surface, and a door 15 covering a front surface. The interior surrounded by the housing 16 and the door 15 forms a heating chamber 17 so that the object to be heated can be placed on the plate 18 and cooked. The door 15 is configured to be openable and closable so that an object to be heated can be taken in and out of the heating chamber 17. The microwave heating means 4 is provided below the plate 18. Although not shown in FIG. 1, an oven heating means 5, a steam heating means 6, and a grill heating means 7 are provided in the heating chamber 17 (or in the vicinity of the heating chamber in the housing).

  FIG. 2 is a control block diagram for controlling the microwave oven 14.

  1 is a commercial power supply.

  Reference numeral 2 denotes a control unit, which uses a microcomputer to control various heating units and each opening / closing unit for heating the object to be heated by acquiring data from various input units and operating according to a program.

  Reference numeral 3 denotes a power supply unit which generates power to be supplied to the control unit 2 by supplying power from the commercial power supply 1. Reference numeral 3a denotes an opening / closing means. The opening / closing means 3a closes (short-circuits) a COM contact and an NC contact of the door switch 10 to be described later.

  Reference numeral 4 denotes microwave heating means. The microwave heating means 4 is a magnetron and a high-voltage power supply (inverter circuit) for generating and supplying power for the magnetron, and is a heating means for heating an object to be heated by microwaves.

  Reference numeral 5 denotes an oven heating means. Examples of the oven heating means 5 include a type in which heaters are provided above and below a heating chamber, and a hot air type in which hot air is sent into a heating chamber to heat an object to be heated. It is a heating means composed of two heaters for heating the air and heating the object to be heated. The number of heaters described here is not limited to two. One or two or more may be used.

  6 is a steam heating means, the figure shows a heater embedded in the boiler and a thermo for preventing abnormal heating of the boiler, and the steam heating means 6 instantaneously supplies the supplied water by the boiler heated to a high temperature by the heater. This is heating means for generating steam and blowing out the expanded steam into the heating chamber to heat the object to be heated.

  Reference numeral 7 denotes a grill heating means, and the grill heating means 6 is a heating means provided on the ceiling of the heating chamber to heat the object to be heated from above.

  Reference numeral 8 denotes a current detecting means. The current detecting means 8 comprises a current transformer, detects a current when various heating means are operating, and inputs the detected current to the control means 2. The current detecting means 8 detects a current of several amperes flowing through various heating means. As the detection value, for example, when the microwave heating means 4 is energized, the maximum heating is 13 A, when the two heaters of the oven heating means 5 are simultaneously energized, 12 A, and the steam heating means 6 is energized. When the power is supplied to the grill heating means 7, it is 10A. When the control means 2 is operated in a standby state without power supply to each heating means, it is 20 mA. Is shown.

  Reference numeral 9 denotes an opening / closing means. The opening / closing means 9 controls the supply of electric power to each heating means in accordance with the output from the control means 2. The opening / closing means 9b to 9f include one end side of various heating means and a door switch described later. The opening / closing means 9a connects the other end (common line) of the various heating means to the other end of the commercial power supply 1 and connects the heating means to the other end of the commercial power supply 1. Power. When an inverter power supply is used as the power supply of the microwave heating means 4, the opening / closing means 9b may be included in the inverter power supply.

  A door switch 10 switches to the NO terminal side when the door 15 is closed, and switches to the NC terminal side when the door 15 is open. The COM terminal of the door switch 10 is connected to the commercial power supply 1 via the current detecting means 8, the NC terminal is connected to the power supply means 3, and the NO terminals are connected to the opening / closing means 9b to 9f, respectively. When the door 15 is closed, the contact of the COM terminal and the contact of the NO terminal are closed, and the contact of the NO terminal is closed. Indicates that the contact of the COM terminal and the NC terminal are closed.

  In a heating cooker provided with an oven function heating means, it is necessary to adjust the door 15 and the main body to a range in which the door switch 10 does not operate even when the door 15 and the main body thermally expand in the opening direction during heating. is there.

  In FIG. 3, reference numeral 11 denotes a control door switch. The control door switch 11 opens and closes in a structurally interlocked manner with the opening and closing of the door for the control means 2 to detect the opening and closing of the door 15. And it is provided independently of the door switch 10.

  Reference numeral 12 denotes an input means. The input means 12 has input keys for selecting a menu to be heated, selecting a heating means, setting a heating time and a heating temperature, and starting and canceling heating.

  Reference numeral 13 denotes a display. The display 13 displays information input by the input unit 12 under the control of the control unit 2, an operation state during heating, and a failure state of the circuit.

  Returning to FIG. 2, reference numeral 14 denotes a current fuse. The current fuse 14 is provided on the side of the commercial power supply 1 and cuts off when a malfunction occurs in the circuit and an abnormal current flows, thereby cutting off the power supply.

  Although not shown, when the door 15 is opened and the contact is not opened due to the failure of the door switch 10, the power supply is short-circuited to blow the current fuse 14 in series with the power supply, thereby cutting the power supply. A monitor switch for opening the line is provided.

  Regarding the three switches described above that operate by opening and closing the door 15, the door switch 10 and the monitor switch are structurally provided so as to operate in conjunction with the opening and closing of the door. The monitor switch is provided so as to operate in conjunction with opening and closing of the door independently of the monitor switch.

  Thus, one side of the commercial power supply 1 is connected to the microwave heating means 4, the oven heating means 5, the steam heating means 6 and the grill heating means 7 via the fuse 14 and the opening / closing means 9a, and the other side of the commercial power supply 1 Is connected to the microwave heating means 4, the oven heating means 5, the steam heating means 6, and the grill heating means 7 via COM contacts, NO contacts and opening / closing means 9b to 9f.

With such a configuration, the control means 2 controls the conduction / interruption of the opening / closing means 9b to 9f to thereby control each of the microwave heating means 4, the oven heating means 5, the steam heating means 6, and the grill heating means 7. When the control door switch 11 detects the open state of the door 15, the control means 2 sets the opening / closing means 9 to the cutoff state, whereby the microwave heating means 4, the oven heating means 5. The current supply to all of the steam heating means 6 and the grill heating means 7 can be cut off. On the other hand, when the control door switch 11 detects the closed state of the door 15, the control means 2 brings the opening / closing means 9 into a conductive state.

  Here, the detection accuracy of the door switch 10 is different from that of the control door switch 11, and when the opening degree of the door 15 further increases after the door switch 10 detects the open state of the door 15, 11 detects that the door 15 is open.

  Next, the operation will be described.

  When the object to be heated is heated by the microwave heating means 4, a malfunction occurs in the adjustment of the operation timing of the door switch 10, and the COM contact of the door switch 10 operates to the NC contact side, and the microwave heating means The operation up to the detection of a defective part when power cannot be supplied to the power supply 4 will be described below.

  To start heating, after the object to be heated is put into the heating chamber 17 and the door 15 is closed, the microwave heating means 4 is selected from the input means 12 and the start of heating is input.

  When the door 15 is opened when the object to be heated is put into the heating chamber, the COM contact of the door switch 10 is connected to the NC contact side, and the power supply means 3 is connected to the commercial power supply 1. The power supply unit 3 which has been supplied with electric power from the commercial power supply 1 generates electric power to be used by the control unit 2 or the like and starts supplying the electric power. The control means 2 supplied with the electric power operates the opening / closing means 3a to close (short-circuit) between the COM contact and the NC contact of the door switch 10 in a circuit manner, so that the power supply is not affected by the operation of the door switch 10. The means 3 can be supplied with electric power from the commercial power supply 1.

  When receiving the input of the start of heating, the control means 2 controls the opening / closing means 9a and 9b to supply electric power to the microwave heating means 4 to start heating. When the microwave heating means 4 starts heating, the current detecting means 8 detects a current value of about 13 A and inputs it to the control means 2.

  After the start of heating, even if an adjustment misalignment (fault) occurs in the door switch 10, the control means 2 does not detect the opening of the door 15 because the control door switch 11 detects the closing of the door 15. It is determined that heating is continuing.

  Since the COM contact of the door switch 10 moved to the NC contact side due to the misalignment of the door switch 10, power supply to the microwave heating means 4 was interrupted, and the current detection value by the current detection means 8 changed from 13A to almost zero. Thus, the control means 2 detects that the heating has stopped.

  When the control means 2 recognizes that the current is zero during heating by the input from the current detection means 8, the opening and closing of the microwave heating means 4 is temporarily performed to confirm the malfunction of the door switch 10 due to the adjustment deviation. The opening / closing means 9 is controlled in order to control the means 9b to cut off the current supply and to supply the current to the other heating means instead.

  Here, the input from the current detecting means 8 is detected by operating the opening / closing means 9c or 9d to supply power to the oven heating means 5 as an alternative heating means.

  In this case, since the COM contact of the door switch 10 is operating to the NC contact side due to the misalignment of the door switch 10, even if power is supplied to the oven heating means 5, the detection value of the current detection means 8 is 2 when normal. When the heaters are energized at the same time, 12A is detected (6A when one heater is energized), but the input becomes almost zero. Therefore, the control means 2 causes a malfunction of the adjustment of the door switch 10. Then, the heating is interrupted and the display means 13 displays the contents of the defect.

  Next, a case where the microwave heating means 4 breaks down as a defective portion will be described.

  The operation of the control means 2 is the same as that described above until the input from the current detecting means 8 is detected by controlling the opening / closing means 9c or 9d to supply electric power to the oven heating means 5 as an alternative heating means.

  When power is supplied to the oven heating means 5, the input from the current detection means 8 detects 10A corresponding to the power consumption of the heater used in the oven heating means 5 because the door switch 10 is normal. Based on the detected current value, the control unit 2 determines that the door switch 10 has no defect, determines the defective portion as the microwave heating unit 4, interrupts the heating, and displays the content of the defect on the display unit 13.

  When controlling the alternative heating means, in consideration of the influence on the object to be heated and the handling of the user, short-time energization is performed for about one second so that the object to be heated and the heating chamber are not heated. Further, the microwave heating means 4 is not used as an alternative heating means such as the oven heating means 5 when heating related to a heater is performed. This is because if a metal container is used during heating, there is a risk that sparks will occur in the container. Instead of the oven heating means 5, a grill heating means 7 or a steam heating means 6 is used.

  In the above, the description has been given of the occurrence of a defect during heating. However, even when there is a defect and heating is started, the defect can be detected by the same control.

  According to the above-described embodiment, it is possible to detect an adjustment misalignment of the door switch, which has a high rate of occurrence of troubles during the lifetime use of the heating cooker.

DESCRIPTION OF SYMBOLS 1 ... Commercial power supply 2 ... Control means 4 ... Microwave heating means 5 ... Oven heating means 8 ... Current detection means 9 ... Opening / closing means 10 ... Door switch 12 ... Input means 13. Display means 15 Door

Claims (5)

A plurality of heating means for heating the object to be heated,
Control means for controlling the energization by selecting the heating means by controlling the opening and closing means and the opening and closing means for controlling the energization to the heating means,
A door switch that operates to control the energization of the heating means in conjunction with opening and closing of the door;
Current detection means for detecting a current supplied to the heating means,
The control means includes
If the detected value of the current detection means is not a value corresponding to the operation of the heating means after the heating of the object to be heated is started, the selected heating means is changed to another alternative heating means and an attempt is made to energize. ,
When the detected value of the current detecting means maintains a value which does not correspond to the operation of the heating means, it is determined that the door switch is defective.   2. The cooking device according to claim 1, wherein the value that does not correspond to the operation of the heating unit is a small current value sufficient for the operation of the control unit.   2. The cooking device according to claim 1, wherein when the detection value of the current detection unit changes to a value corresponding to the operation of the heating unit, it is determined that the heating unit is defective.   2. The cooking device according to claim 1, further comprising a control door switch for detecting opening and closing of the door, wherein the control means controls the switch based on a detection result of the control door switch.   The heating cooker according to any one of claims 1 to 4, wherein the plurality of heating units are at least two of a microwave heating unit, an oven heating unit, a steam heating unit, and a grill heating unit.

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