JPH08322714A - Cooker - Google Patents

Abstract

PURPOSE: To improve safety of a rice-cooker to troubles of an electricity feeding controlling means by providing in multiplicity the electricity feeding controlling means for shutting energizing of electricity to a heating means by using a pot switch, a pot temp. sensor and a temp. fuse. CONSTITUTION: When a pot 4 is not stored in an inner frame 2, a pot switch 26 outputs a signal of absence of a pot to stop feeding of a high frequency electric current and to stop heating. When rice cooking and temp. keeping are performed and the detecting temp. of a pot temp. sensor 23 or a lid temp. sensor 52 reaches at least 120 deg.C being a first specified temp., feeding of the high frequency electric current is stopped and heating of the pot 4 is checked. In addition, in the case when a microcomputor and temp. sensors 23, 52 become out of order, energizing of electricity is kept as it is. However, even in the worst case, when the temp. reaches at least 129 deg.C being a second specified temp., temp. fuses 21 and 22 are worked and a circuit for feeding an electric source to an induction heating means and heaters 20 and 51 is shut down. Therefore, there exists no possibility of returning of this circuit again and heating of the pot 4 is completely checked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooker such as a rice cooker having improved safety.

[0002]

2. Description of the Related Art In a cooker such as a rice cooker equipped with a heating means, a temperature which normally shuts off energization to the heating means when the temperature control means for controlling the on / off of the heating means fails during cooking. A safety device such as a fuse is provided. This thermal fuse, the final safety device, is provided in series with the heating means. The temperature control means includes a control component such as an electromagnetic relay or a thyristor that detects the temperature of the container or the container storage portion of the cooker main body in which this container is stored, and that turns on and off the heating means based on the detected temperature information. . When these control parts are broken, the heating means remains energized, the temperature of the main body rises abnormally, and in order to prevent the risk of melting or igniting the main body, etc. The device is equipped with. However, if this safety device also fails, there is no power supply control means that shuts off the power to the heating means, the container continues to be heated, and there is a risk that the plastic parts such as the main body will melt as described above. come.

In fact, in the conventional cooker, only one temperature fuse is provided for one heating means, and this one temperature fuse fails, and the heating means is supplied with power. If the supply circuit is always short-circuited, the heating means may remain energized when the temperature control means fails.

[0004]

As described above, in the conventional cooking device, there are few safety devices for cutting off the power supply to the heating means when the temperature rises abnormally. The means may remain energized, and further improvement in safety has been desired.

The present invention is intended to solve such problems, and an object of the present invention is to provide a cooker with improved safety against failure of the power supply control means of the heating means.

[0006]

In order to achieve the above-mentioned object, a cooking device of the present invention comprises a container for containing an object to be cooked, a container accommodating portion for removably accommodating the container, and heating for heating the container. Means, container detecting means for detecting the presence / absence of a container in the container accommodating portion, and first power supply control means for cutting off the power supply to the heating means while the container detecting means detects the absence of the container, A temperature detecting means for detecting the temperature of the container, a second power supply control means for cutting off the power supply to the heating means while the temperature detecting means detects a predetermined temperature or more exceeding 100 ° C., the container or the container The temperature of the housing or the vicinity of the heating means or the temperature of the lid provided above the container is the second
And a third power supply control means for cutting off the power supply to the heating means when the temperature exceeds a predetermined temperature higher than the temperature at which the power supply to the heating means is cut off. The means includes two or more means, and cannot energize after the energization to the heating means is cut off. The total of the first power feeding control means, the second power feeding control means and the third power feeding control means. It is equipped with four or more safety devices.

[0007]

In the cooker of the present invention, when the container is not accommodated in the container accommodating portion, the container detecting means detects this and the first power supply control means cuts off the power supply to the heating means. At the time of cooking, the container containing the food to be cooked is housed in the container housing portion, and the heating means is energized to heat the container. At this time, the temperature detecting means detects the temperature of the container, and when the detected temperature exceeds a predetermined temperature exceeding 100 ° C., the second power feeding control means cuts off the power supply to the heating means. If the second power supply control means fails, the heating means remains energized, and the temperature of the container may rise above the predetermined temperature to further rise. Alternatively, when the temperature of the lid portion above the container becomes equal to or higher than a predetermined temperature higher than the predetermined temperature in the second power supply control means, the third power supply control means cuts off the power supply to the heating means. afterwards,
The energization cannot be restored and the heating means is not energized again. Further, there are two or more third power supply control means, and even if one third power supply control means fails, if the other third power supply control means is normal, when the abnormal temperature rises as described above. The power supply to the heating means will be cut off.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the cooker according to the present invention will be described below with reference to FIGS. The cooker of this embodiment is a rice cooker. In FIG. 1, which is an overall cross-sectional view, 1 is a rice cooker main body which is a cooker main body, and this is an inner frame 2 which is a bottomed cylindrical container accommodating portion with an open upper surface, and the inner frame 2 inside And the outer frame 3 provided in the. The inner frame 2 and the outer frame 3 are made of plastic. Reference numeral 4 denotes a pot which is a container for containing rice and water to be cooked therein. The pot 4 is formed of an aluminum material as a main body and has a bottomed cylindrical shape with an open top. It is removably housed inside. Also,
On the outer surface of the pot 4, at the bottom and at the bottom of the side,
A heat generating layer 5 made of a magnetic metal material for heating the is provided.

An induction coil 1 for inductively heating the heat generating layer 5 is located on the outer surface of the inner frame 2 at a bottom portion and a lower portion of a side surface thereof with a predetermined distance from the heat generating layer 5 of the pot 4.
1 and 12 are provided. These induction coils 11 and 12 which are components of the heating means are covered from the outside by a coil cover 13 made of plastic and fixed to the inner frame 2.
Outside the coil base 13, a plurality of ferrite cores 14 are provided orthogonal to the winding direction of the induction coils 11 and 12. Further, a magnetic shield 15 made of an aluminum material for preventing leakage of magnetic flux is provided facing the outer surfaces of the induction coils 11, 12.

On the upper part of the outer surface of the inner frame 2, a body heater 20 such as a cord heater is provided as a heating means for keeping the inner frame 2 warm. Also, the inner frame 2
Two thermal fuses 21 and 22 as third energization control means are attached to the outer surface of the. These thermal fuses 21 and 22 are of non-reset type and operate at 129 ° C. to blow. And one temperature fuse 21
Is located near the induction coil 11 on the bottom surface of the inner frame 2, and the other thermal fuse 22 is located above the side surface of the inner frame 2. Further, a pan temperature sensor 23 having a heat-sensing part composed of a negative characteristic thermistor is provided above the center of the coil cover 13 as a pan temperature detecting means for detecting the outer surface temperature of the pan 4 so as to be vertically movable. There is. The pot temperature sensor 23 is biased upward by a spring 24 which is an elastic member, penetrates the bottom of the inner frame 2 and projects upward, and contacts the bottom of the pot 4.

A switch lever 25 fixed to the pan temperature sensor 23 penetrates the coil cover 13 and projects downward. Below the coil cover 13, a pan switch 26 is provided as container detecting means for detecting the presence or absence of the pan 4 in the inner frame 2. The pan switch 26 has an opening / closing element 27 that is operated by the switch lever 25.
That is, if the pan 4 is not housed in the inner frame 2, the switch lever 25, which is pushed by the spring 24 and moved up together with the pan temperature sensor 23, lifts the opening / closing member 27 to lift the pan switch.
26 contacts are closed and no pot signal is output. On the other hand, when the pan 4 is housed in the inner frame 2, the pan 4 pushes down the pan temperature sensor 23 and the switch lever 25, and the opening / closing member 27 also lowers in conjunction with this, so that the contact point of the pan switch 26 is changed. It opens, and the pot present signal is output.

A control board 30 is provided in the lower portion of the cooker body 1. The control board 30 includes an inverter circuit for supplying a high frequency current to the induction coils 11 and 12. On the other hand, a heating substrate 32 is arranged in a storage chamber 31 formed in the rear part of the cooker body 1.
A switching element 33 for controlling the supply of high frequency current to the induction coils 11 and 12 is mounted on the heating substrate 32. A radiator 34 is attached to the switching element 33. Further, an exhaust port 35 is provided above the rear surface of the outer frame 3 so as to face the inside of the storage chamber 31, and the outer frame 3
An intake port 36 is provided at the lower back and bottom of the.

Reference numeral 41 is a lid that covers the upper opening of the pot 4 so as to be openable and closable. The lid 41 includes an outer lid 42 and the outer lid 42.
An outer lid cover 43 provided along the outer periphery of the lower side of the
And a heat dissipation plate 44 made of an aluminum member that is attached to the lower side of the pan 4 to form a space. It is detachably locked via a lid retainer 47. Reference numeral 48 denotes an annular lid packing sandwiched and held between the outer lid cover 43 and the heat dissipation plate 44, and when the lid body 41 is closed, the lower end of the lid packing 48 is a flange portion on the upper surface of the pan 4. Stick to. A clamp button 49 is provided on the front side of the lid body 41, and by pushing and operating the clamp button 49, the lid body 41 can be opened around a hinge 50 provided on the rear side of the lid body 41 as a rotation center. . On the other hand, on the upper surface of the heat radiating plate 44 forming the lower surface of the lid 41, a lid heater 51 such as a cord heater is provided as a heating means for heating the heat radiating plate 44 during rice cooking and heat retention. Further, on the upper surface of the heat radiating plate 44, as a lid temperature detecting means for detecting the temperature of the heat radiating plate 44, a lid temperature sensor including a negative characteristic thermistor is provided.
52 are provided. The lid heater 51 constitutes a parallel circuit with the body heater 20 of the inner frame 2. In addition, 53 is a steam port for discharging steam from the pan 4 to the outside, and 54 and 55 are operation panels provided on the upper portion of the outer lid 42 and the front surface of the outer frame 3, respectively.

Next, the circuit configuration of the rice cooker will be described with reference to FIG. In the figure, reference numeral 61 denotes a microcomputer, which is well known, and in addition to a control device 62 and an arithmetic device 63 which constitute a microprocessor, a time measuring device 64 including various counters and a memory including ROM and RAM. The device 65 is provided. Microcomputer 61
An input device 66 including an A / D converter is connected to the input side of the pan temperature sensor 23 through the input device 66.
The lid temperature sensor 52 and the pan switch 26 are connected to an operation switch 67 which is an operation means provided on the operation panels 54 and 55. On the other hand, the microcomputer 61
An output device 71 is connected to the output side of, and an induction heating means 72 for electromagnetically heating the pot 4 and a triac for controlling the on / off of the body heater 20 and the lid heater 51 at the same time through the output device 71. Heater drive means 73 having switch means
Etc. are connected. In addition to these, the output device 71 has L
A display drive means 75 for controlling the display of the display means 74 composed of a CD or an LED is connected, and a buzzer 76 for notifying the end of cooking rice is provided.
The buzzer drive means 77 for controlling the ringing of the motor is connected, and the motor drive means 79 for driving the cooling fan motor 78 not shown in FIG. 1 is connected.

The microcomputer 61 uses, as input information, the operation signal of the operation switch 67 for starting rice cooking and heat retention, the temperature data from the pan temperature sensor 23 and the lid temperature sensor 52, and the signal from the pan switch 28. In addition to this input information, based on time information from the timekeeping device 64, etc., according to a control sequence set in the ROM of the storage device 65 in advance, the induction heating means 72, the body heater 20 and the lid heater
51, display means 74, buzzer 76 and cooling fan motor 78 are controlled. Reference numeral 81 is a power failure backup means connected to the output device 71.
An auxiliary power source is supplied to 61 through the microcomputer driving means 82, and the contents stored in the storage device 65 and the operation of the clock device 64 are retained.

The induction heating means 72 is provided with a high frequency current adjusting means 83 for supplying a predetermined high frequency current based on the output signal from the microcomputer 61. When a high-frequency current is supplied to the induction coils 11 and 12, an alternating magnetic field is generated in the induction coils 11 and 12, and an eddy current is generated in the heating layer 5 of the pan 4 in the magnetic field. When the electric current is converted into Joule heat, the heat generating layer 5 generates heat to heat the pot 4.

As a software function of the microcomputer 61, the induction heating means 72 including the induction coils 11 and 12, the body heater 20 and the lid heater 51 are operated while the panless signal is output from the pan switch 26. When the temperature detected by the first power supply control means for shutting off the power supply to the pan and the pot temperature sensor 23 or the lid temperature sensor 52 exceeds the normal boiling temperature of 100 ° C, that is, a first predetermined temperature, for example, 120 ° C or higher. In addition, the induction heating means 72, the body heater 20, and the lid heater 51 have a second power supply control means for cutting off the power supply. The first
The predetermined temperature of is a high temperature that cannot be reached during normal rice cooking. In the rice cooker, the timing when the water disappears further after boiling and is dried up is detected as the time of cooking, and at the time of dry up, the temperature detected by the temperature sensor 23 slightly exceeds the boiling temperature. In consideration of this, for example, 120 ° C. is set as the first predetermined temperature as described above. In addition, even if it is not a rice cooker, in a normal cooker, the temperature of the pan is almost the boiling temperature.
Since 100 ° C. is often used as the maximum temperature, the first predetermined temperature may be set to a temperature higher than 100 ° C.

The both temperature fuses 21, 22 which are the third power supply control means are connected in series with each other, and in the circuit for supplying power to the high frequency current generator of the induction heating means 72 and the heater 20. , 51 connected in series in the circuit that supplies power. Therefore, one of the temperature fuses 21 and 22 is the first of the second power feeding control means.
If the temperature exceeds the second predetermined temperature (for example, 129 ° C.) higher than the predetermined temperature, the induction heating means 72, the body heater 20 and the lid heater 51 will be de-energized, and
It is impossible to restore the power supply after the power supply is cut off. The second predetermined temperature is set higher than the first predetermined temperature because the temperature fuses 21 and 22 are erroneously operated even though the microcomputer 61 and the temperature sensors 23 and 51 are normal. This is to ensure that nothing happens. Multiple thermal fuses 2
The operating temperatures of 1, 22 or the second predetermined temperature may all be the same.

As described above, the safety device for the heating means includes the first power feeding control means, the second power feeding control means, and the second power feeding control means.
There are a total of four third power supply control means.

Next, the operation of the above configuration will be described. As described above, when the pan 4 is not housed in the inner frame 2, the pan switch 26 outputs a pan-less signal. During that time, the supply of the high frequency current is stopped and the heating is blocked. The body heater 20 and the lid heater 51 are also not energized. Thus, during normal use, safety is ensured when the pan 4 is not housed in the inner frame 2. That is,
When the pan 4 is not provided, the body heater 1 and the lid heater 51 do not unnecessarily heat the rice cooker body 1. Along with this, high-frequency current is generated in the induction coil 1 without the pan 4.
If it is supplied to 1 and 12, there is a risk that the control circuit will be destroyed due to overload, but this can be prevented.

At the time of cooking rice, a pan 4 containing rice and water
Is housed in the inner frame 2 and the induction coils 11, 12 are energized with a high frequency current to heat the pot 4. This heating is controlled based on the temperature and time detected by the temperature sensors 23 and 52,
The steps of hot water cooking, boiling heating, boiling detection, continuous boiling heating, cooking detection, and spotting are sequentially performed to cook rice. After completion of this rice cooking, the process proceeds to the heat retention process.

A pan temperature sensor is used for this rice cooking and heat retention.
23 or when the temperature detected by the lid temperature sensor 52 exceeds the first predetermined temperature of 120 ° C., the supply of high frequency current is stopped,
The heating of the pan 4 is blocked. Body heater 20 and lid heater 51
Is not energized. This prevents excessive temperature rise during normal use.

If the microcomputer or the temperature sensors 23, 52 forming the second power feeding control means fails, the induction coils 11, 12 and the heaters 20, 51 remain energized, and the pot 4, etc. The temperature may exceed the first predetermined temperature and further increase. However, in the worst case, the temperature of the thermal fuses 21 and 22 is the second predetermined temperature.
When the temperature becomes 129 ° C. or higher, the thermal fuses 21 and 22 operate to cut off the circuit for supplying power to the induction heating means 72 and the heaters 20 and 51. After that, this circuit never returns again, and the heating of the pan 4 is completely blocked.

Since the two thermal fuses 21 and 22 are connected in series and provided, one of the thermal fuses 21 and 22 is provided.
Even if the unit fails and is always short-circuited, the other temperature fuses 22 and 21 are activated when the temperature rises abnormally,
Energization to the induction heating means 72 and the heaters 20 and 51 is surely cut off. Therefore, the safety is improved, and the rice cooker body 1
It is possible to prevent danger such as melting of plastic parts.

Further, as described above, the thermal fuses 21 and 22 are
Even before the operation, the safety is ensured by the first power supply control means for preventing the heating when the pan 4 is not present and the second power supply control means for stopping the heating of the pan 4 when the temperature rises abnormally. . Therefore, even if both the thermal fuses 21 and 22 are out of order, overheating is prevented if the second power feeding control means is normal. Further, when the thermal fuses 21 and 22 are activated, they must be replaced after that, but when the heating is stopped by the second power feeding control means, there is no problem in the subsequent normal use. In this way, the safety is reliably ensured by the multiple safety devices.

Next, a second embodiment of the cooker according to the present invention will be described with reference to FIGS. 3 and 4. In addition,
The cooker of this embodiment is also a rice cooker. In FIG. 3, which is an overall cross-sectional view, 101 is a rice cooker body which is a cooker body, and the rice cooker body 101 is an outer frame 102 and an outer frame 102.
And an inner frame 103 forming a container accommodating portion provided therein. The inner frame 103 includes an upper inner frame member 104 and a lower inner frame member 105.
The bottom support plate 106 is fixed to the lower side of the lower inner frame member 105 and is supported on the bottom portion of the outer frame 102 by the support 107.
The upper portion of the upper inner frame member 104 is supported on the upper portion of the outer frame 102 by a frame spacer 108. Reference numeral 109 denotes a pot, which is a container. The pot 109 is formed into a bottomed cylindrical shape with an open top, and contains rice, which is the food to be cooked, and water therein. Further, a flange-shaped handle portion 110 protruding horizontally outward is formed on the uppermost portion of the outer side surface of the pot 109. The handle 110 may be formed around the entire circumference of the pot 109 or may be formed partially. Also, the pot 109
Although it is detachably accommodated in the inner frame 103, the handle portion 110 of the pan 109 is positioned on the frame spacer 108 in this accommodated state.

An opening 111 is formed in the center of the lower inner frame member 105. Further, a rice cooking heater 112, which is an electric heater such as a sheathed heater, which is a main heating means for radiatively heating the pan 109, is provided on the upper peripheral portion of the lower inner frame member 105. The rice cooking heater 112 is supported by a heater support 113. The heater support 113 penetrates the lower inner frame member 105 and is supported by the lower support plate 106.

Reference numeral 116 denotes a heater plate serving as a heat transfer member. The heater plate 116 is formed in a substantially annular shape, and is positioned above the rice cooking heater 112 at a lower portion inside the inner frame 103 while maintaining a predetermined distance. The pot 109 is placed on top. The heater plate 116 is supported from below by a plurality of heater plate support rods 117 on the inner peripheral portion thereof, and these heater plate support rods 117 are supported.
Are supported by the heater plate supporter 118 supported by the supporter 107 or the lower support plate 106. Also,
A gap 119 is formed between the outer periphery of the heater plate 116 and the inner side surface of the inner frame 103, and via this gap 119,
The radiant heat of the rice cooking heater 112 is supplied to the side surface of the pan 109 inside the inner frame 103.

Further, on the upper portion of the outer surface of the upper inner frame member 104, a body heater 121 such as a cord heater is provided as a heating means for keeping the inner frame 102 warm.
Two thermal fuses 122 as a third energization control means,
123 are arranged side by side.

On the upper side of the heater plate support 118, a pan temperature sensor 124 as a temperature detecting means for detecting the outer surface temperature of the pan 109 is supported so as to be vertically movable. The pan temperature sensor 124 is biased upward by a spring 125 and protrudes above the heater plate 116 to
It is elastically in contact with the central part of the outer bottom surface of 109. A switch lever 126 is fixed to the pan temperature sensor 124. On the other hand, below the heater plate support 118, a pan switch 127 is provided as container detection means. The pan switch 127 has an opening / closing member 128 operated by the switch lever 126, and outputs a pan-less signal and a pan-existing signal in the same manner as the pan switch 26 of the first embodiment. is there.

Further, a cord reel 131 for winding a power cord is provided on the lower outer side of the outer frame 102.
A power supply board 132 and a display board 133 are provided between the side surfaces of the outer frame 102 and the inner frame 103. The power supply board 132 includes a heater driving unit and the like. On the other hand, the display substrate 133 provided on the front surface of the outer frame 102 is provided with an operation switch, displays time and travel display, and the display unit 134 shows this display to the user.

Reference numeral 141 denotes a lid body that opens and closes the top opening of the rice cooker body 101. The lid body 141 includes an outer lid 142 and an outer lid 142.
The heatsink 143 fixed to the lower side of the heatsink 143 and the inner lid 14 that is detachably locked to the bottom of the heatsink 143 via studs 144.
It consists of 5. The inner lid 145 closes the top opening of the pan 109 so that it can be opened and closed. And the heat sink 14
On the upper surface, which is the back surface of 3, the lid heater 146 composed of a cord heater or the like is used as a heating means for heating the heat dissipation plate 143.
Is provided. The lid heater 146 electrically forms a parallel circuit with the body heater 121.

By the way, the pot 109 is mainly made of an AC4CH aluminum material which is excellent in thermal conductivity and corrosion resistance. And when manufacturing Pan 109,
The inner surface of 109 is roughened by blasting with alumina powder or the like, and then coated with a paint mainly containing FEP resin and then dried (about 15 minutes at 200 ° C.) to form a primer layer. Next, on the surface of the primer layer, a water level line is printed at a predetermined position by pad printing or the like with a paint mainly composed of an FEP resin having a different color. Next, a paint mainly composed of transparent PFA resin is applied and dried (at 380 ° C. for about 20 minutes) to form a coating layer mainly composed of fluorine-based plastic on the inner surface of the pot 109. On the other hand, the outer surface of the pot 109 is blasted with alumina powder or the like to roughen the surface of the aluminum material 16 and then coated with a paint mainly containing silicone resin and containing PTFE resin, etc., and baked (at 360 ° C). After about 15 minutes), a coating layer mainly composed of silicone resin-based plastic is formed with a film thickness of 10 to 40 μm.

The pan 109 has a side surface shape whose diameter gradually increases from the lower part to the upper part of the pan 109, and the lower part of the outer surface of the pan 109 has a smaller inclination with respect to the horizontal plane. The central portion of the outer bottom surface of the pan 109 that contacts the pan temperature sensor 124 is located above the outermost peripheral portion 109a of the bottom surface of the pan 109 that contacts the heater plate 116. The difference in height is preferably 1.5 to 3.0 mm.

The heater plate 116 is the rice cooking heater 11
In order to absorb the radiant heat from 2 and to improve the heat conductivity to the pan 109, an aluminum material is used as a material. At the same time, in order to improve heat resistance and appearance, and to improve absorption of radiant heat from the rice cooking heater 112, the heater plate 116 is provided with a black alumite coating containing nickel oxide by secondary electrolysis. It is formed with a thickness of 4 μm or more.

As shown in detail in FIG. 4, the heater plate 116 has a vertical cylindrical bent portion 116a at the innermost peripheral portion, and a horizontal portion 116b is formed radially outward from the upper edge of the bent portion 116a. It is bent. In addition, the bent portion 11 extends from the outer peripheral edge of the horizontal portion 116b.
6c rises, and an inclined portion 116d that descends radially outward from the upper edge of the bent portion 116c is formed. Further, an inclined portion 116f that rises radially outward from the outer peripheral edge of the inclined portion 116d via the bent portion 116e is formed. Further, the bent portion 116g is bent downward from the outer peripheral edge of the inclined portion 116f. The horizontal portion 116b at the inner peripheral portion is a place where the heater plate support rod 117 comes into contact, and serves to stabilize the support of the heater plate 116. Also,
The heater plate 116 and the heater plate support rod 117 are fixed by caulking, but the bent portion 116a at the center of the heater plate 116 is for caulking.
The heater plate 116 has a pan 109 at its inclined portion 116f.
It comes into contact with the inclined portion of the outer bottom surface outer peripheral portion 109a. The inclined portion 116f forming the contact portion with the pan 109 ends at a position where the gap with the pan 109 does not become too wide inward in the radial direction, and the inclined portion 116d on the inner peripheral side of the inclined portion 116f is Pot 10
The gap with 9 is narrowed. In addition, rice cooker 112
Is arranged near the contact portion between the heater plate 116 and the pan 109 in order to improve the heat transfer efficiency between the heater plate 116 and the pan 109.

The inner frame 103 is made of an aluminum material having a high efficiency of reflecting the radiant heat from the rice cooking heater 112. Along with this, the surface treatment of the inner frame 103 is performed only by degreasing without alumite treatment so as to increase the reflection efficiency, or by forming a thin alumite coating of 4 μm or less to improve the reflection efficiency of the alumite coating. The structure is designed to prevent the deterioration as much as possible.

In the rice cooker of the second embodiment, as in the case of the first embodiment, the electric power to the heaters 112, 121 and 146 is cut off while the pan-less signal is output from the pan switch 127. And a second power supply control means for shutting off the power supply to the heaters 112, 121, 146 when the temperature detected by the pan temperature sensor 124 is a first predetermined temperature, for example, 120 ° C. or higher. Is provided as a function of the microcomputer. The both thermal fuses 122 and 123, which are the third power supply control means, are connected in series with each other and are connected in series with the circuit that supplies power to the heaters 112, 121 and 146. Thermal fuse 122, 12
3 is a non-reset type, and the operating temperature is 129 ° C, for example.

Next, the operation of the above configuration will be described. As in the first embodiment, the pot 10 is placed in the inner frame 103.
When 9 is not accommodated, the pan switch 127 outputs a pan-less signal, while the heaters 112, 121,
146 is not energized. At the time of cooking rice, the pot 109 containing rice and water is housed in the inner frame 103, and the heaters 112, 121, 1
The pot 109 etc. are heated by energizing 46. The operation control of the rice cooking heating or the warming heating is also performed by adjusting the heating amount by turning on and off the rice cooking heater 112, the body heater 121 and the lid heater 146 according to the temperature of the pan 109 detected by the pan temperature sensor 124. To do.

A pan temperature sensor is used for this rice cooking and heat retention.
When the temperature detected by 124 becomes 120 ° C. or higher, which is the first predetermined temperature, the energization of the heaters 112, 121, 146 is cut off.
Further, when the microcomputer or the temperature sensor 124, which constitutes the second power feeding control means, fails, the heater 11
2, 121, 146 may remain energized, and the temperature of the pan 109 or the like may exceed the first predetermined temperature and further increase. However, the temperature of the thermal fuses 122 and 123 is the second
When the temperature rises above 129 ° C., which is the predetermined temperature, the temperature fuses 122 and 123 are operated to interrupt the power supply to the heaters 112, 121 and 146, and thereafter the power supply cannot be restored. Further, since the two temperature fuses 122 and 123 are connected in series and provided, even if one of the temperature fuses 122 and 123 fails and is always short-circuited, the other temperature fuses 122 and 123 will have an abnormal temperature rise. The fuses 123 and 122 are activated to surely cut off the power supply to the heaters 112, 121 and 146.

As in the second embodiment, the rice heating heater 112, which is an electric heater, is used as the main heating means for cooking rice, and a rice cooker using the induction heating means 72 as in the first embodiment is used. In contrast, when the pan switch 127 fails, the rice cooker heater 112 heats the pan even without the pan 109, so that the second power feeding control means and the two third power feeding elements including the temperature fuses 122 and 123 are used. The effect of the control means becomes more effective.

By the way, in the conventional rice cooker, the heater plate for transmitting the heat of the rice cooking heater to the pot placed on the top is formed in a substantially horizontal flat plate shape. Therefore, when used for a long time, due to factors such as the load on the pan, the entire heater plate may be greatly deformed, or the heater plate may be locally deformed, resulting in normal contact between the heater plate and the pan. This has hindered the cooking performance such as uneven heating of the pot and impaired the appearance of the product. Further, when foreign matter such as rice grains falls on the heater plate, the foreign matter may be present between the heater plate and the pan. In this state, a predetermined amount of heat is not given to the pan from the heater plate, and cooking performance is impaired. Further, in the conventional rice cooker, the heating is insufficient where the pan is not in contact with the heater plate, particularly the peripheral portion of the pan.

On the other hand, in the rice cooker of the second embodiment, since the heater plate 116 is provided with the bent portions 116c, 116e, 116g, the strength of the heater plate 116 is increased.
Even if used for a long time, the load of the pan 109 or the rice cooker 11
It is possible to prevent the heater plate 116 from being deformed due to the influence of heat from 2. That is, the heater plate 116
Even if the
The c and 116g suppress downward deformation, and the bent portion 116e having a concave shape on the upper surface side suppresses upward deformation. By preventing the heater plate 116 from being deformed in this way, it is possible to prevent the appearance from being deteriorated and prevent the regular contact between the heater plate 116 and the pan 109 from being hindered. Therefore, the cooking performance is stable without causing uneven heating of the pan 109.

Although the pan 109 contacts the inclined portion 116f of the heater plate 116, even if foreign matter 150 such as rice grains falls on the inclined portion 116f, the foreign matter 150 is still caused by the inclination of the inclined portion 116f itself. , Gather or flow toward the lower bend 116e. This will prevent the foreign matter 150 from
You can prevent it from interfering with the regular contact between 116 and pot 119,
Heat exchange between the heater plate 116 and the pan 119 can be normally performed. Therefore, deterioration of cooking performance can be prevented and a highly reliable rice cooker can be provided.

Further, as described above, the heater plate 116
In order to prevent the deformation of the heater plate 116, a downward bent portion 116g is formed on the outermost peripheral portion of the heater plate 116. Therefore, at this bent portion 116g, the gap between the heater plate 116 and the pan 109 is wide. The radiant heat from the heater 112 is supplied to the outer surface of the pot 109 through the gap 119 between the outer periphery of the heater plate 116 and the inner surface of the inner frame 103, and is absorbed there, so that the outer peripheral portion of the pot 109 is heated. Is promoted and the insufficient heating can be prevented. As a result, the pan 109 can be heated uniformly and a rice cooker with stable cooking performance can be provided.

The present invention is not limited to the above embodiment, and various modifications can be made. For example,
The position for providing the third power supply control means such as a temperature fuse is not limited to that of the above-described embodiment, but may be provided so that the temperature of the container can be directly detected, or the lid portion above the container, that is, the lid body. It may be provided in the. Further, the number of the third power feeding control means composed of a temperature fuse or the like is not limited to two as in the above embodiment, and three or more may be provided. Even when three or more units are provided, all the third power feeding control units are connected in series with each other and are inserted in series in the circuit that supplies power to the heating unit. Furthermore, although the rice cooker has been described as an example in the above-described embodiment, the present invention is naturally applicable to cookers other than the rice cooker.

[0047]

According to the present invention, the first power supply control means for cutting off the power supply to the heating means when there is no container in the container housing portion, and the temperature of the container exceeding a predetermined temperature exceeding 100 ° C. are detected. In addition to the second power supply control means for shutting off the power supply to the heating means during the operation, the temperature of the container, the container accommodating portion, the vicinity of the heating means, or the lid above the container is the second power supply control means. Is provided with two or more third power supply control means that cut off the power supply to the heating means when the temperature exceeds a predetermined temperature higher than the temperature at which the power supply to the heating means is cut off and cannot restore the power supply thereafter. The safety when no container is provided is ensured by the first power supply control means, the second power supply control means prevents an excessive temperature rise, and the temperature is further abnormal due to a failure of the second power supply control means. Part of the third power feeding control means Even if there is a failure, the power supply to the heating means is cut off by another third power supply control means, and therefore the safety is improved.

[Brief description of drawings]

FIG. 1 is an overall sectional view showing a first embodiment of a cooking device according to the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the same.

FIG. 3 is an overall sectional view showing a second embodiment of the cooker according to the present invention.

FIG. 4 is an enlarged view of a part of the pan and the heater plate shown in FIG.

[Explanation of symbols] 2 Inner frame (container housing) 4 Pan (container) 21, 22 Temperature fuse (third power supply control means) 23 Pan temperature sensor (temperature detection means) 26 Pan switch (container detection means) 41 Lid Body (lid) 61 Microcomputer (first power supply control means, second
Power supply control means) 72 induction heating means (heating means) 103 inner frame (container housing) 109 pan (container) 112 rice cooking heater (heating means) 122, 123 temperature fuse (third power supply control means) 124 pan temperature sensor (Temperature detection means) 127 Pan switch (Container detection means) 141 Lid body (lid part)

Claims (1)

[Claims] 1. A container for containing an object to be cooked, a container housing portion for detachably housing the container, a heating means for heating the container, and a container detecting means for detecting the presence or absence of the container in the container housing portion. The first power supply control means for cutting off the power supply to the heating means while the container detection means detects the absence of the container, the temperature detection means for detecting the temperature of the container, and the temperature detection means for detecting the temperature of 100 ° C. Second power supply control means for shutting off the power supply to the heating means while detecting a temperature higher than or equal to a predetermined temperature, and the temperature of the container or the container accommodating portion, the heating means vicinity portion, or the lid portion provided above the container. And a third power supply control means for cutting off the power supply to the heating means when the temperature exceeds a predetermined temperature higher than the temperature at which the second power supply control means cuts off the power supply to the heating means. 2 or more power supply control means In addition, the power supply cannot be restored after the power supply to the heating means is cut off, and there are a total of four or more safety devices including the first power supply control means, the second power supply control means, and the third power supply control means. Cooker characterized by having.