JP3395509B2 - Combined cooking device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined cooking device having two or more heating sections and a drive circuit section located above a second heating section. Things. [0002] In recent years, electromagnetic cookers have begun to spread in place of gas stoves as commonly used heating cookers, and their characteristics of cleanliness, comfort and safety have been evaluated. Was. It is also characterized by being easy to control because of its electrical configuration. In addition, a type of combined cooking device having a roaster function of storing a fish in a dedicated unit together with a gas stove and baking it with a heater or the like has also become widespread. [0003] A conventional composite cooking device will be described below with reference to FIG.
And FIG. FIG. 5 is a side sectional view of a conventional composite heating cooker. 101 is a heating coil, 103 is a printed wiring board, 104 is a transistor for inductively heating the heating coil 101, 105 is a radiation fin for cooling the transistor 104, 106 is a cooling fan for cooling the radiation fin 105, 107 is a wind tunnel frame, 108 is a filter frame,
Reference numeral 109 denotes a temperature sensor, 117 denotes an upper unit frame containing the above components, 102 denotes a heater, and 110 denotes a lower unit frame in which the heater 102 is built. Printed wiring board 103
Is provided with electronic components for driving the heating coil 101 and the heater 102. Next, a circuit configuration for heating the heating coil 101 and the heater will be described with reference to FIG. FIG. 6 is a circuit block diagram of a conventional composite cooking device. 111 is an inverter circuit that drives the heating coil 101 and incorporates the transistor 104, 112 is a first drive circuit that outputs a drive signal to the inverter circuit 111, and 113 is a heater 10
4, a heater drive circuit 114 for outputting a drive signal to the heater drive circuit, 115 an operation unit for operating the first and second drive circuits 112 and 114,
Reference numeral 115 denotes a microcomputer that controls the first and second drive circuits 112 and 114 and the cooling fan 106 based on the outputs of the operation unit 115 and the temperature sensor 109. [0005] A method of cooling the electronic components of the composite cooking device having the above-described configuration will be described. Cooling fan 106
Rotates when the inverter circuit 111 operates, and wind outside the main body is sent from the filter frame 108 to the radiation fins 105 to cool the transistor 104 and other electronic components. Even if the heater driving circuit 113 operates, the cooling fan 106
Rotates to block the heat rising from the heater frame 110 and cool the electronic components. In this manner, the temperature around the printed wiring board 103 is stabilized so that the performance of the electronic components does not change due to heat. In case of abnormality, that is, the filter frame 10
When the cooling fan 106 is not rotated or the cooling fan 106 does not rotate, the temperature around the printed wiring board 103 increases due to the heat of the radiation fins 105 or the heater 104. This is detected by the temperature sensor 109 and output to the microcomputer 116. The microcomputer 116 discriminates this and stops heating the currently operating heating unit so as not to increase the peripheral temperature of the printed wiring board 103. As described above, since the cooling fan 106 rotates regardless of the heating, the printed wiring board 103 is heated.
The electronic components wired above are cooled, and the heating can be stopped by the temperature sensor 109 even in the event of an abnormality, so that the performance of the electronic components is maintained and the safety and reliability are improved. [0007] However, in the above-described conventional combined heating cooker, when the heater is heated in a state where the cooling air is stopped, heat is transmitted through the lower unit frame and the upper unit frame, and the printing is performed. The peripheral temperature of the lower surface of the wiring board rises. However, since the temperature sensor is located on the upper surface of the printed wiring board, the heat rising from the lower unit frame is transmitted from the lower surface of the printed wiring board to the lead wires of the electronic components before the temperature sensor detects abnormal temperature, When the temperature was increased from the inside, the performance sometimes changed. In the conventional example, the temperature of the heater is 95 at the maximum.
Degrees, and when the cooling fan is stopped, the temperature around the printed wiring board becomes 95 degrees. The general heat-resistant temperature of an electrolytic capacitor, which is one of the electronic components, is 85 degrees, and it goes without saying that the performance of the electrolytic capacitor changes. Therefore,
Since electronic components having high heat resistance were used, the cost was high. Further, since the cooling fan is stopped immediately before the heater is reheated, the temperature around the printed wiring board may increase again due to the residual heat of the heater. Was stopped and heating could not be resumed. [0010] In order to solve the above-mentioned problems, the present invention provides a drive type heating section having electronic components, a printed wiring board for wiring electronic components and the like, and cooling the electronic components. A cooling fan, a temperature sensor that detects a peripheral temperature of the printed wiring board, an arithmetic processing unit that controls the electronic components and the like according to an output of the temperature sensor, and at least the printed wiring board, a cooling fan, a temperature sensor, And an upper unit frame for storing arithmetic processing means, and a lower unit frame having a heating element such as a heater and positioned below the temperature sensor, and provided with a vent hole below the temperature sensor,
The temperature sensor is connected via the vent when the cooling air stops.
To receive heat radiation directly from the lower unit frame.
The arithmetic processing unit is configured to drive the cooling fan when heating of the heating unit or the heater is started, and to heat the heating unit or the heater regardless of an output of the temperature sensor until a predetermined time has elapsed. Row
The temperature sensor detects high temperature after a predetermined time
Then, the heating of the heating unit or the heater is stopped , and the temperature sensor normally detects an abnormal temperature due to the cooling air.
Is not detected, but when the cooling air stops, the temperature sensor
Directly receives the heat radiation from the lower unit frame and detects abnormal temperatures.
Outgoing occurs early. In addition, when heating is stopped once and then restarted, heating is restarted regardless of the temperature of the temperature sensor for a predetermined time, and the cooling fan is rotated to discharge the heat to the outside of the main body and the surroundings of the printed wiring board. The temperature can be lowered, and the temperature sensor detects the high temperature by the heat stored in the printed wiring board, stops the heating, and eliminates the problem that the heating cannot be restarted. DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 is a temperature sensor.
A ventilation hole is provided in the lower part of
When stopped, heat from the lower unit frame through the ventilation holes
It is provided at a position where it directly receives radiation, and the arithmetic processing means comprises:
When the heating of the heating unit or the heater is started, the cooling fan is driven, and the output of the heater of the heating unit or the lower unit frame housed in the upper unit frame is controlled for a predetermined time without depending on the output of the temperature sensor. No, predetermined time
When the temperature sensor detects a high temperature after a lapse, the heating is performed.
By stopping the heating of the heat unit or the heater, normal
Temperature sensor does not detect abnormal temperature due to cooling air
However, when the cooling air stops, the temperature sensor
Heat radiation directly to detect abnormal temperatures early.
You. In addition, when heating is stopped once and then restarted, heating is restarted regardless of the temperature of the temperature sensor for a predetermined time, and the cooling fan is rotated to discharge the heat to the outside of the main body and the surroundings of the printed wiring board. The temperature can be reduced, and the problem that the temperature sensor detects the high temperature by the heat stored in the printed wiring board, the heating is stopped, and the heating cannot be restarted can be eliminated. (Embodiment 1) FIG. 1 is a side sectional view of a composite cooking device showing a first embodiment of the present invention. In FIG. 1, 1 is a heating coil, 3 is a printed wiring board, 4 is a transistor for driving the heating coil 1 by inverter, 5 is a radiating fin for radiating the transistor 4, 19 is an electronic component for heating, and 6 is a radiating fin 5 And a cooling fan for cooling the electronic components 19, 7 is a wind tunnel frame,
Reference numeral 8 denotes a filter frame, 9 denotes a temperature sensor, 10 denotes an upper unit frame containing the above components, 2 denotes a heater, 11 denotes a lower unit frame containing the heater 2, and 12 denotes a ventilation hole provided below the temperature sensor 9. is there. Next, a circuit configuration for heating the heating coil 1 and the heater will be described with reference to FIG. FIG. 2 is a circuit block diagram of the combined cooking device showing the first embodiment of the present invention. Reference numeral 13 denotes an inverter circuit that drives the heating coil 1 and incorporates the transistor 4, and 14 denotes an inverter circuit.
3, a first drive circuit for outputting a drive signal to the heater 3, a heater drive circuit 15 for driving the heater 2, a second drive circuit 16 for outputting a drive signal to the heater drive circuit, and a first and a second drive 17 An operation unit 18 for operating the circuits 14 and 16 includes first and second operation units based on the output of the operation unit 17 and the temperature sensor 9.
Is a microcomputer that controls the drive circuits 14 and 16 and the cooling fan 6. A method for cooling the electronic component 19 arranged on the printed wiring board 3 of the thus-configured combined cooking device will be described. Normally, the cooling fan 6 rotates when the inverter circuit 13 operates, and air outside the main body is blown from the filter frame 8 to the radiation fins 5 to cool the transistor 4 and other electronic components. Even when the heater drive circuit 15 operates, the cooling fan 6 rotates to prevent heat rising from the lower unit frame 11 and cool the electronic components. Thus, the temperature around the printed wiring board 3 is stabilized. In the event of an abnormality, that is, when the filter frame 8 is blocked
When does not rotate, the temperature around the printed wiring board 3 rises. Since the temperature sensor 9 is on the same printed wiring board 3 as the radiation fins 5, when the inverter circuit is operating, the temperature of the radiation fins 5 is directly received and detected.
When the heater 2 is operating, the heat increases the peripheral temperature of the printed wiring board 3 via the lower unit frame 11 and the upper unit frame 10. Since the temperature sensor 9 directly receives the heat of the lower unit frame 11 through the ventilation holes 12, the temperature sensor 9 can detect the heat more quickly than the lower surface temperature of the printed wiring board 3. The microcomputer 18 receives the detection information from the temperature sensor 9, determines that the temperature is abnormal, stops the heating of the currently operating heating unit, and does not increase the temperature around the printed wiring board 3. Regardless of the type of heating, the transistor 4 and the electronic component 19 provided on the radiation fin 5 are
In the event of an abnormality, heating is stopped by early detection of the temperature sensor to prevent an abnormal rise in the temperature of the electronic component. (Embodiment 2) FIG. 3 is a side sectional view of a combined cooking device showing a second embodiment of the present invention. In FIG. 3, 1 is a heating coil, 3 is a printed wiring board, 4 is a transistor for driving the heating coil 1 by an inverter, 5 is a radiating fin for radiating the transistor 4, 19 is an electronic component for heating, and 6 is a radiating fin 5 And a cooling fan for cooling the electronic components 19, 7 is a wind tunnel frame,
Reference numeral 8 denotes a filter frame, 9 denotes a temperature sensor, 10 denotes an upper unit frame containing the above components, 2 denotes a heater, 11 denotes a lower unit frame containing the heater 2, and 12 denotes a ventilation hole provided below the temperature sensor 9. is there. The temperature sensor 9 is provided on the printed wiring board 3 at a position surrounded by the cooling fan 6 and the wind tunnel frame 7 to detect the temperature. The circuit configuration for heating the heating coil 1 and the heater is the same as that in FIG. A method for cooling the electronic component 19 arranged on the printed wiring board 3 of the composite cooking device having the above-described configuration will be described. Normally, the cooling fan 6 rotates, the heat of the lower unit 11 through the heat radiation fins 5 or the ventilation holes 12 is cut off by the cooling air, and the temperature sensor 9 detects the ambient temperature outside the main body. When there is no cooling air, the radiation fins 5
Alternatively, heat from the lower unit 11 through the ventilation holes 12 increases the temperature of the space surrounded by the wind tunnel frame 7 and the printed wiring board 3. The temperature sensor 9 is provided at the position shown in FIG. 3 because the temperature rise gradient between the normal time and the abnormal time is large. Therefore, the microcomputer 18 inputs the detection output of the temperature sensor at predetermined time intervals. It can be detected earlier than the example. In the first and second embodiments, the temperature sensor 9 is provided on the printed wiring board 3, and the radiation fin 5 and the lower unit frame 1 are provided.
Although the heat from the first device can be directly received, the same effect can be obtained without providing the temperature sensor on the printed wiring board at a position where the heat can be directly received. (Embodiment 3) FIG. 4 is a flowchart of a microcomputer of a combined cooking device according to a third embodiment of the present invention. In step 1, the operation signal of the inverter circuit 13 or the heater drive circuit 15 is detected from the operation unit 17. When the operation signal is output, the process proceeds to step 2 where the inverter circuit 13
Alternatively, an operation signal is output to the heater drive circuit 15. Step 3 detects whether a timer described later has reached a predetermined time, and proceeds to step 4 when the timer count ends. Step 4 is to determine the detection input of the temperature sensor 9,
If the temperature sensor 9 (temperature around the printed wiring board 3) is abnormal, the process proceeds to step S5. Normally, the above steps are repeated. Then, in step 1, when a stop signal is detected from the operation unit 17, the process proceeds to step 6. Step 6 starts timer counting. Since the cooling fan 6 is stopped immediately after the heating of the printed wiring board 3 is stopped, the internal temperature rises to some extent. As a result, the temperature sensor 9 detects the temperature equal to or higher than the temperature, and thereafter, the inverter circuit 13 or the heater drive circuit 15 cannot start operating again until the temperature decreases. In order to prevent this, the timer is counted for a predetermined time in steps 6 and 3, and the temperature around the printed wiring board 3 is cooled by the cooling fan 6 during that time. If the cooling fan 6 does not rotate, or if the filter frame 8 continues to be clogged, step 3
When the timer count ends, the process proceeds to step 4. Therefore, in step 5, the inverter circuit 13 or the heater drive circuit 15 can be stopped, and the influence of heat of the electronic components can be prevented. As described above, when heating is started again, by performing heating without using the temperature sensor for a predetermined time, it is possible to prevent a problem that the heating operation cannot be started. In the first to third embodiments, the case where the upper unit accommodates an induction heating type heating device and an inverter circuit and the lower unit accommodates a resistance heating type heater has been described. Resistance heating (Nichrome wire heater,
The same effect can be obtained even if the heater housed in the lower unit is a heating element such as a gas burner. As described above, according to the first aspect of the present invention, the temperature sensor detects an abnormal temperature early and stops heating.
The heating can be continued even if the heating is restarted. This protects electronic components from abnormal temperatures.
In addition to this, it is possible to improve the cooking performance and eliminate the disadvantage that heating is not performed during reheating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view of a combined cooking device showing a first embodiment of the present invention. FIG. 2 is a circuit block diagram of the combined cooking device. FIG. 4 is a side cross-sectional view of a combined cooking device showing a second embodiment. FIG. 4 is a flowchart of the operation of the combined cooking device showing a third embodiment of the present invention. Side sectional view [FIG. 6] Same as above, circuit block diagram of combined cooking device [Description of symbols] 1 heating coil 2 heating element (heater) 3 printed wiring board 4 transistor (switching semiconductor) 5 radiating fin 6 cooling fan 7 wind tunnel frame Reference Signs List 8 filter frame 9 temperature sensor 10 upper unit frame 11 lower unit frame 12 vent hole 18 arithmetic processing means

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hirofumi Noma 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yuji Fujii 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-7-272847 (JP, A) JP-A-1-149395 (JP, A) JP-A-5-251165 (JP, A) JP-A-53-105053 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H05B 6/12 H05B 11/00

Claims (1)

(57) [Claim 1] A driving type heating unit having an electronic component,
A printed wiring board for wiring electronic components and the like; a cooling fan for cooling the electronic components; a temperature sensor for detecting a peripheral temperature of the printed wiring board; and controlling the electronic components and the like in accordance with an output of the temperature sensor. An arithmetic processing means, an upper unit frame accommodating at least the printed wiring board, the cooling fan, the temperature sensor, and the arithmetic processing means, and a lower unit frame having a heating element such as a heater and located below the temperature sensor. Providing a ventilation hole at the lower part of the temperature sensor,
The temperature sensor opens the ventilation hole when the cooling air stops.
Through which heat radiation from the lower unit frame is directly received
The arithmetic processing unit is configured to drive the cooling fan when the heating of the heating unit or the heater is started, and the heating unit or the heater without depending on the output of the temperature sensor until a predetermined time has elapsed. There <br/> line heating, the temperature sensor after lapse of a predetermined time has detected an elevated temperature
When notified, the combined heating cooker stops heating of the heating unit or the heater .