JPS6359916A - Rice cooker - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object 1-1 of the Invention] (Field of Application of Industry-1) The present invention relates to a rice cooker in which a pot is heated by a rice-cooking heater to perform a rice-cooking operation.

(Prior art) In conventional rice cookers, in order to control the end time of rice cooking,
Switch devices that combine magnetic shunt steel, permanent magnets, operating levers, microswitches, etc. as temperature detection elements are widely used, and such switch devices are generally constructed as follows.

In other words, a heat-sensitive cap is provided that presses against the outer bottom of the rice-cooking pot when it is installed in a predetermined position. Inside this heat-sensitive cap, magnetic shunt steel, which loses its magnetism at a certain Curie point temperature, conducts heat. The temperature of the rice to be cooked is detected as the temperature of the pot using the magnetic shunt steel. At this time, the Curie point temperature of the magnetic shunt steel is -
It is selected to be approximately equal to the L temperature (generally around 130° C.). In addition, a permanent magnet is attached to the tip of the operating lever, which is rotatable between three positions. It is rotated to the first position, and is rotated back to the second position in response to the release of attraction of the permanent magnet as the magnetic shunt steel loses its magnetism. The microswitch is turned on when the operating lever is moved to the first position and turned off when it is rotated to the second position, and in the on state, the rice cooking heater is turned on. The structure is such that an electric path is formed.

Therefore, in a rice cooker equipped with a switch device having the configuration described in 1-1, when the operating lever is rotated to the first position, the rotating state is such that the permanent magnet and the magnetic shunt steel are attracted to each other. At the same time, the microswitch is turned on, and in response, the rice cooking operation by the rice cooking heater is started. After this, as the rice cooking continues, the inside of the pot exhibits a so-called dry-up state, and the temperature (detected temperature) of the magnetic steel becomes higher than the temperature used for cooking rice, and its magnetism disappears, causing permanent damage. As the attraction of the magnet is released, the operating lever is rotated back to the second position and the microswitch is turned off, so that the rice cooking heater is cut off and the rice cooking operation is ended.

In addition, this rice cooker has a so-called double-cooking function that allows you to reheat the pot for a short time after the rice has been cooked, thereby removing excess water from the rice and making it more delicious. is becoming popular, and such rice cookers are equipped with a double-cooking timer that starts operating when the microswitch is turned off, and the double-cooking operation is controlled by the output of this timer. It is composed of

(Problem to be solved by the invention) Thermal conductivity between the outer bottom of the pot and the heat-sensitive cap is 1.112.
The thermal conductivity between the heat-sensitive cap and the magnetic shunt steel varies to some extent due to the processing accuracy and assembly accuracy of each of these parts, so the actual temperature of the pot and the temperature detected by the magnetic shunt steel may differ. It is inevitable that errors will occur between the two. On the other hand, since the Curie point temperature of magnetic shunt steel is constant, the temperature of the pot when the magnetic shunt steel loses its magnetism, that is, the temperature of the pot when rice cooking is terminated by the switch device, is the temperature of the pot when the rice cooking operation is terminated by the switch device. It will vary depending on the device. Therefore, as a result,
In the conventional rice cooker, there is a possibility that control of the end time of the rice cooking operation may be inaccurate.

One possible way to deal with these problems is to provide an adjustment mechanism to adjust the thermal conductivity of the magnetic shunt steel, but it is actually extremely difficult to provide such an adjustment mechanism. be.

For this reason, in the past, a predetermined tolerance temperature range was set for the operating temperature of the switch device (the temperature at which magnetic shunt steel loses its magnetism), and when the rice cooker was manufactured, the operating temperature of the switch device was set to the above tolerance temperature range. Quality control is carried out to ensure that the width is within the range.

In other words, in the conventional rice cooker, the actual situation is that the control of the end time of the rice cooking operation is relatively loose, and this point has been an unresolved problem.

Furthermore, in the near future, it is expected that rice cookers configured to always perform the above-mentioned double heating during normal rice cooking operations will become mainstream. However, when a rice cooker is actually used, in addition to the normal cooking as described above, it is also used to cook rice for seasoned rice. The following problems arise. In other words, when cooking rice for takikomi rice, seasonings such as soy sauce are added to the pot and tend to burn when the rice is cooked, so it is not recommended to heat the rice by cooking it twice. It is. For this reason, if the configuration is such that double-cooking and heating are always performed as described above, there will be a problem in that the cooked rice will be extremely burnt when cooking for rice that has been left over. In addition, as a means to suppress the amount of scorching on cooked rice, lowering the operating temperature of the switch device (the end temperature of the rice cooking operation) may be considered, but in conventional rice cookers, as mentioned above, the switch device Since the operating temperature of the device is a constant temperature that depends on the Curie point temperature of the magnetic shunt steel, it is impossible to suppress the amount of scorching by the above-mentioned means.

The present invention has been made in view of the above circumstances, and its 1-1 purpose is to control the end timing of the rice cooking operation by +1-11 precisely.
To provide a rice cooker that has effects such as being able to cook rice deliciously by double-cooking and heating, and also being able to cook rice for cooked rice while suppressing and controlling the occurrence of burnt rice. It is on offer.

[Structure of the Invention] (Means for Solving Problems) The present invention provides a rice cooking heater for heating a pot, and a rice cooker that detects the temperature of the rice to be cooked and outputs temperature information (= sign) according to the detected temperature. If each temperature detection means is provided, when the temperature indicated by the temperature information signal reaches a predetermined temperature 17 during the rice cooking operation by the rice cooking heater, the rice cooking heater is switched to a power-off state, and then the predetermined conditions are set. A double-cooking heating pattern for re-energizing the rice-cooking heater when the above-mentioned temperature information signal reaches a predetermined eddy current during the rice-cooking operation using the rice-cooking heater. 1.1) A control means is installed (J, the control means is configured to have a memory section i' that stores a large number of cooking/drinking heating patterns for switching to the power-off state and thereafter maintaining the power-off state in -1-). , the rice cooking operation according to the double-cooking heating pattern and the rice cooking operation according to the boiling/drinking heating pattern can be selectively executed.

(Function) The temperature information signal used to control the end time J' of the rice cooking operation is not a fixed signal, as it changes according to the temperature of the rice to be cooked detected by the temperature detection means. ,
Even if the thermal conductivity between the cooked rice and the temperature detection means varies, the temperature detected by the temperature detection means can be easily compensated for. Therefore, it becomes possible to accurately control the end timing of the rice cooking operation. In addition, the control means is
The rice cooking operation is based on a double-cooking heating pattern in which the rice cooking heater is switched to a power-off state based on the temperature information signal, and then the rice cooking heater is reenergized when a predetermined condition is satisfied17, and the rice cooking operation is performed based on the temperature information signal. Since the rice cooking heater is configured to switch to a power-off state and then selectively perform the rice cooking operation according to the cooking and drinking heating pattern without re-energizing as described in -1-, the rice can be cooked deliciously by twice-cooking and heating. 1- Not only can it be cooked, but there is no risk of increasing the amount of browned rice when making cooked rice. In particular, when cooking rice for the first time, the temperature detected by the 9-stage eddy-electric detection sensor can be easily compensated for as described above, so it is possible to suppress burning by cutting off the rice heater for 7 hours earlier. Planning also becomes +tJ ability.

(Example) First, in FIG. 3, 1 is a substantially cylindrical outer case, 2 is a bottom frame fitted in the lower part of the outer case 1, 3 is an inner case disposed inside the outer case 1, and 4 are outer case 1 and inner case 3
A heat insulating key 5 interposed therebetween is a pot detachably installed within the inner case 3. Further, 6 is a rice cooking heater disposed on the inner bottom of the inner case 3, 7 is a heat-retaining heater wrapped around a part of the outer periphery of the inner case 3, and 8 is rotatably supported on the outer case 1 = 9 = The held lid 9 is a locking mechanism that holds the lid 8 in a locked state. Reference numeral 10 denotes a heat transfer cap that is provided so as to be pressed against the outer bottom of the pot 5 by the spring force of a spring (not shown), and a thermistor 11, for example, which serves as a lower stage for detecting temperature in a heat transfer manner, is disposed inside the cap. ing. Therefore, this thermistor 11 detects the temperature of the rice to be cooked as the bottom temperature of the corresponding pot 5 (hereinafter referred to as pot bottom temperature &p), and has a resistance value corresponding to the detected temperature. The temperature information signal Sd is output as a temperature information signal Sd.

Further, in FIG. 4, reference numeral 12 denotes a clock device disposed on the outside of the outer case, which consists of a display section 13 that digitally displays "hours" and "minutes" and an operation section 14. Incidentally, since the time = 1 device 1f12 has a normal clock function and a timer function for a well-known timer switch, selection and adjustment of each function is performed by each operation button 14a of the operation section 14. There is. Furthermore, 15 is also an outside game 1
This is a heating pattern selection device which is an operation means disposed on the outside of the porridge, and has, for example, three operation buttons 15a, and these operation buttons 15a can be used to select a heating pattern for porridge cooking, a heating pattern for double cooking, and a heating pattern for double cooking, which will be described later. Any heating pattern for cooked rice can be selected. At this time, the heating pattern selection device 15 sends a pattern selection signal S that can specify the selected heating pattern.
Output p.

Note that 16 is a display device disposed on the outside of the outer case 1, which has, for example, four display lamps 16a, each of which indicates the current operating state by lighting. At this time,
The display device 16 is "cooking rice".

The operating states of "double cooking", "uniform cooking", and "keep warm" are displayed.

Next, the electrical configuration will be explained according to FIGS. 1 and 2. First, in Figure 2 showing the outline of the electric circuit configuration, 17
is a bidirectional three-terminal cyrisk (hereinafter referred to as q% cyrisk), and a series circuit between this and the rice cooking heater 6 is connected to receive power from the plug 17a. Further, the warming heater 7 is connected in parallel with the thyristor 17, so when the thyristor 17 is turned off, the rice cooking heater 6 and the warming heater 7 are energized in series, and the rice cooking heater 6 is substantially cut off. Then, the pot 5 is heated over low heat. Further, when the thyristor 17 is turned on, only the rice cooking heater 6 is energized, which generates heat at a relatively high output and heats the pot 5 over high heat. 18
is a voltage regulating device that constitutes the power supply control means 19 between the thyristor 17 and the thyristor 17, which is interposed in the energizing path of the rice cooking heater 6, and controls the output amount by suppressing the voltage between the terminals of the rice cooking heater 6. Note that the output amount of the rice cooking heater 6 does not necessarily have to be adjusted by the voltage regulator 18 as shown in L, but can also be adjusted by, for example, phase control or on/off duty ratio control of the thyristor 17. It is.

Therefore, the voltage regulator 1B has the thyristor 1
7 and the clock device 12, it is controlled by a control circuit device 20 serving as a control means. As shown in FIG. 1, this control circuit device 2o is configured as a microcomputer including a storage section 211, a time control section 22, and an arithmetic processing section 23.
Three types of programs for controlling the thyristor 17 and the voltage regulator 1B in a predetermined manner (this will be described later)
are stored corresponding to the three types of heating patterns. Further, the time control section 22 is provided to receive the clock pulse Pc from the oscillator 24, and outputs a time information signal St for timing based on a command from the arithmetic processing section 23. The arithmetic processing unit 23 is provided to receive the temperature/reaction information signal Sd from the thermistor 11, the pattern selection signal Sp from the heating pattern selection device 15, and the time information signal St from the time control unit 23 as data input, respectively. A program corresponding to the manually input pattern selection signal Sp is read out from the storage unit 21, and the thyristor 17 and voltage adjustment device 18 are adjusted based on the read program, the temperature information signal S d ·l, and the time information signal St. The heating pattern is controlled to obtain a heating pattern corresponding to the program. Further, the arithmetic processing section 23 also controls the clock device 12.

Now, in the following, specific operations executed by the arithmetic processing section 23 based on the program read from the storage section 21 will be explained with reference to FIGS. 5 to 7 as well as the effects of each heating pattern. In addition, Fig. 5 (A), Fig. 6
7 and 7 show temperature characteristic curves corresponding to time T and pot bottom temperature D('C) on the horizontal and vertical axes, respectively, and in FIG. 5(B), time T is shown on the horizontal and vertical axes, respectively. and a temperature characteristic curve corresponding to the output P (W) of the rice cooking heater 6.

(I)... Heating pattern for cooking porridge (see Fig. 5) When a heating pattern for cooking porridge is selected by the heating pattern selection device 15, and a pattern selection signal Sp is output that can identify the heating pattern. , arithmetic processing section 23
Based on the program from the storage unit 21, the thyristor 17 is turned on to energize only the rice cooking heater 6. Therefore, the pot 5 is heated over high heat and the bottom temperature of the pot rises relatively rapidly, and the thermistor 11 detecting this, outputs the change in its resistance value as a temperature information signal Sd. Then, at time tl, when the temperature information signal Sd corresponding to the pot bottom temperature D-80° C. (7) Heat the pot 5 over low heat. As a result, the temperature at the bottom of the pot is lowered relatively slowly by 1-5 degrees.2) The temperature at the bottom of the pot reaches 98℃. When the time reaches (time t2), the arithmetic processing unit 23 causes the time control unit 22 to
A command is issued to output the time information signal St after 0 minutes have elapsed.

When the above-mentioned time information signal St is output at time t3, which is 20 minutes after time t2, the operation processing unit 23 that has received it cancels the operation of the voltage regulator 18 and simultaneously turns off the thyristor 17. Then, the rice cooker 6 and the heat-retaining heater 7 are energized in series, and the pot 5 is further heated over low heat. + Due to the action described in 1-1 below, the rice stored in the pot 5 can be cooked into porridge with a suitable amount of water.Especially, during such ``cooking'', the temperature at the bottom of the pot is low. Since the pot 5 was heated over a low heat of 100 watts from time t2 to time t3, the cooking liquid in the pot 5 would not boil over due to excessive boiling. It is.

(II) Heating pattern for double-cooking (see Fig. 6) A heating pattern for "double-cooking" is selected by the heating pattern selection device 16, and a rice-cooking start command signal that allows identification of the heating pattern is issued. Barrel pattern selection signal S
When p is output, the arithmetic processing unit 23 turns on the thyristor 17 to start the rice cooking operation based on the program from the storage unit 21, and then heats the pot 5 with high heat using the rice cooker heater 6 to cook the pot. Boil the water in 5. During this boiling period, the bottom temperature of the pot is maintained at about 100°C, but the water in the pot 5 evaporates. When it is absorbed by the rice and accelerates the so-called dry-up state, the temperature at the bottom of the pot rises rapidly.

As a result, the temperature at the bottom of the pan from No. 11 to D-130
When the temperature information signal Sd corresponding to °C is output (time t
4) In response, the arithmetic processing unit 23
At the same time, a command is issued to the time control section to output the time information signal St to the 5 minute diameter - 16 - = connection to the 22.

At time t5, which is 5 minutes after time t4, when the time information signal St mentioned above is output, the arithmetic processing unit 23 that has received it turns on the thyristor 17 for one minute, and then turns on the thyristor 17 for one minute. During the period, the pot 5 is heated to +1 over high heat to perform so-called double cooking, and after that, the above-mentioned steaming operation is performed.

In other words, when the predetermined condition that 5 minutes have passed after the end of the rice cooking operation 1' control is satisfied, the above two-sided cooking operation control is performed. This removes excess water from the cooked rice, making it more delicious.

(m)... Heating pattern for cooked rice (see Figure 7) This heating pattern is used when making cooked rice using the pot 5.
This is a solution to the problem that seasonings such as soy sauce are added to the inside of the container, which tends to cause it to burn. That is, when the heating pattern selection device 15 selects a heating pattern for cooked rice and outputs a pattern selection signal Sp capable of specifying the heating pattern, the arithmetic processing unit 23
is the thyristor 1 based on the program in the storage unit 21.
7 is turned on in the same way as each heating pattern described above.

After this, the pot 5 exhibits a dry-up state and the bottom temperature of the pot rises rapidly, and when the thermistor 11 outputs a temperature information signal Sd corresponding to the pot bottom temperature JiD=110° C. at time t6, the arithmetic processing section 23 corresponds to the thyristor 1.
7 is held in the OFF state to shift to uneven operation.

In this way, the degree of increase in the temperature at the bottom of the pot is suppressed to a low level, and the rice is controlled so as not to be heated on two sides, thereby making it difficult for the rice that has been cooked to become scorched. A heating pattern suitable for cooking rice can be obtained.

In the first embodiment, the time control unit may be configured to sound a buzzer or the like by means of 11 when a predetermined period of time has elapsed after the shift to the uneven operation.

1. As described above, this embodiment is provided with a thermometer 11 that detects the temperature of the rice to be cooked through the pot 5, and also creates a heating pattern for cooking rice porridge, The present invention is characterized by the provision of a control circuit device 20 that selectively controls the heating pattern for double-cooked rice and the heating pattern for cooked rice. At this time, since the temperature information signal Sd is based on a resistance value that is easiest to handle as an electrical modification, it can be easily corrected. As a result, even if the thermal conductivities between the pot 5 and the heat-sensitive cap 10 and between the heat-sensitive cap 10 and the thermistor 11 vary during manufacturing,
” The temperature detected by the thermistor 11 corresponding to the two-legged temperature information signal can be compensated very easily. Therefore,
Not only the end timing of the rice cooking operation can be controlled, but also the rice cooking operations for cooking porridge and cooked rice as described in the embodiments can be accurately controlled. Further, since a microswitch having a conventional mechanical contact point is not required to detect the temperature of the pot 5, problems such as shortened lifespan due to wear of the contact point are not caused. Moreover, the control circuit device 20 has two heating patterns: one for double-cooking, in which the rice heater 6 is re-energized after one large rice-cooking operation, and one for rice-cooking, in which the rice-cooking heater 6 is not re-energized as described above after the rice-cooking operation is finished. Since the rice heating pattern is configured to selectively execute the heating pattern for rice, the rice can be cooked deliciously by double cooking and heating, and there is no possibility that the amount of burnt rice will increase when making cooked rice.

In particular, in this embodiment, when the heating pattern for cooked rice is selected, the rice cooking operation is ended at a temperature lower than normal, so that the amount of charring can be further suppressed.

[Effects of the Invention] As is clear from the description below, according to the present invention, a temperature detection means for detecting the temperature of cooked rice and outputting a temperature information signal according to the detected temperature is provided, and a rice cooking heater is provided. 2. Switching the rice cooking heater to a power-off state when the temperature indicated by the temperature information signal reaches a predetermined temperature during the rice cooking operation, and then re-energizing the rice cooking heater when a predetermined condition is satisfied. When the temperature indicated by the temperature information signal reaches a predetermined temperature in the rice cooking operation based on the boiler heat pattern and the rice cooking operation using the rice cooking heater, the rice cooking heater is switched to a power-off state, and then the power is cut off. The configuration allows for selective heating of the rice-cooking station that maintains the state and rice-cooking operation by <turn, so it is possible to more accurately control the end time of the rice-cooking operation and improve reliability over the service life. ,
In addition, by double-cooking and heating, the rice can be cooked deliciously, and even when rice is cooked for seasoned rice, the amount of burnt rice can be suppressed, which is an excellent effect.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention.
The figure is a schematic diagram of the electrical configuration, Figure 2 is a schematic electrical circuit diagram, Figure 3 is a partially cutaway front view of the whole, Figure 4 is a front view of the whole, and Figure 5 (A ) is a temperature characteristic diagram for explaining the action, FIG. 5(B) is an output characteristic diagram for explaining the action, and FIGS. 6 and 7 are temperature characteristic diagrams for explaining the action. In the figure, 5 is a pot, 6 is a rice cooking heater, 7 is a heat retention heater, and 11
15 is a thermistor (temperature detection means), 15 is a heating pattern selection device, 17 is a bidirectional three-terminal thyrisk, 18 is a voltage regulator, 19 is a power supply control means, 20 is a control circuit device (control means), and 21 is a memory. part, 22 is a time control part, 2
3 indicates an arithmetic processing section. Applicant: Toshiba Corporation -': 22 -

Claims (1)

[Claims] 1. A rice-cooking heater for heating a rice-cooking pot, a temperature detection means provided to detect the temperature of the rice to be cooked and outputting a temperature information signal according to the detected temperature, and a rice-cooking operation by the rice-cooking heater. For double cooking, when the temperature indicated by the temperature information signal reaches a predetermined temperature, the rice cooker is switched to a power-off state, and when a predetermined condition is satisfied thereafter, the rice cooker is energized again. When the temperature indicated by the temperature information signal reaches a predetermined temperature during the rice cooking operation using the heating pattern and the rice cooking heater, the rice cooking heater is switched to a power-off state, and the power-off state is maintained thereafter. A control means having a storage unit storing heating patterns, and the control means is configured to be able to selectively execute a rice cooking operation according to the heating pattern for double-cooking and a rice cooking operation according to the heating pattern for cooked rice. A rice cooker characterized by: