JPH021486B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) 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, a switch device that combines magnetic shunt steel as a temperature detection element, a permanent magnet, an operating lever, a micro switch, etc. is widely used to control the end time of rice cooking. Such a switch device is 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 selected to be approximately equal to the temperature at which rice is cooked (generally around 130° C.). In addition, a permanent magnet is attached to the tip of an operating lever that is rotatable between two positions, and this operating lever is capable of attracting the permanent magnet to magnetic shunt steel in response to an external operation. While being rotated to the first position, it is rotated back to the second position in response to the permanent magnet being released from attraction as the magnetic shunt steel loses its magnetism. The micro switch is turned on when the control lever is rotated to the first position and turned off when the control lever is rotated to the second position, and in the on state, the rice cooking heater is turned on. The configuration is such that an electric path is formed.

Therefore, in a rice cooker equipped with a switch device configured as described above, when the operation lever is rotated to the first position, the rotation state is changed due to the attraction between the permanent magnet and the magnetic shunt steel. At the same time, the micro switch 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 when the temperature (detected temperature) of the magnetic steel becomes higher than the rice cooking temperature and its magnetism disappears, the permanent magnet's attraction is released. Accordingly, the operating lever is rotated back to the second position and the micro switch is turned off, so that the rice cooking heater is cut off and the rice cooking operation is ended.

(Problems to be Solved by the Invention) In recent years, rice cookers have been developed that are capable of cooking rice porridge in addition to the above-mentioned normal rice cooking. It is seen as promising. By the way, when cooking rice porridge in this way, the output of the rice cooking heater is reduced before the inside of the pot reaches a boiling state, thereby preventing the cooking liquid in the pot from boiling rapidly. It is necessary to control it so that it does not boil over. Therefore, in order to perform such control,
It is necessary to detect a state in which the temperature of the rice to be cooked in the rice cooker reaches a predetermined temperature below the boiling point. However, in the conventional rice cooker, the temperature that can be detected by the switch device is 130, which corresponds to the Curie point temperature of magnetic shunt steel.
℃ only, it is impossible to control porridge cooking as described above. To deal with this, a temperature sensor for controlling porridge cooking may be provided separately from the switch device, but if such a configuration is adopted, magnetic shunt steel is used as the temperature detection element. Since two types of sensor and temperature sensor are required, not only is there a lot of wasted parts, but the structure is also complicated.

The present invention has been made in view of the above circumstances, and its purpose is to be able to automatically execute other controls including porridge cooking control in addition to normal rice cooking control with simple operations, and to control rice cooking at one temperature. To provide a rice cooker which is effective in simplifying the structure by simply providing a detection means.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a temperature detection means that detects the temperature of the rice to be cooked and outputs a temperature information signal according to the detected temperature, the energization state of the rice cooker heater for heating the pot, and the heat generation. A power supply control means for controlling the amount of power, a time information signal for timing, the temperature information signal, and a plurality of types of programs including heating patterns for normal rice cooking and heating patterns for porridge cooking stored in advance. Information processing means for controlling the supply control means to selectively obtain a plurality of types of heating patterns for heating the pot, and operation means for arbitrarily selecting the plurality of types of heating patterns. be.

(Function) The information processing means controls the energization state and calorific value of the rice cooking heater through the power supply control means, and also controls such control in a heating pattern for normal rice cooking and for porridge cooking. The heating pattern is executed based on a program corresponding to the heating pattern selected by the selection means. Therefore, in addition to normal rice cooking control, other controls including porridge cooking control can be easily performed. In addition, the temperature information signal necessary for each control as described above is output from the temperature detection means according to the temperature of the rice to be cooked, and contains many types of information, so it is different from the conventional one. This eliminates the need to provide two types of temperature detection elements.

(Example) First, in FIG. 3, 1 is a substantially cylindrical outer case, 2 is a bottom frame fitted to the lower part of the outer case 1, and 3
4 is a heat insulating material interposed between the outer case 1 and the inner case 3; 5 is an inner case disposed within the outer case 1;
is a pot detachably mounted inside the inner case 3. Further, 6 is a rice cooking heater disposed at the inner bottom of the inner case 3, 7 is a heat-retaining heater wrapped around the upper outer periphery of the inner case 3, 8 is a lid rotatably supported on the outer case 1, and 9 is a locking mechanism that holds the lid 8 in a locked state. Reference numeral 10 denotes a heat transfer cap which is provided in pressure contact with the outer bottom of the pot 5 by the force of a spring (not shown), and inside thereof there is a temperature detecting means, such as a thermistor 11, which is thermally conductive with the cap.
is installed. Therefore, this thermistor 11
is the temperature of the food to be cooked in the pot 5 that corresponds to this.
(hereinafter referred to as pot bottom temperature D), and a change in resistance value corresponding to the detected temperature is output as a temperature information signal Sd.

In addition, in Fig. 4, 12 is a clock device disposed on the outside of the outer case, which indicates the hours and minutes.
It consists of a display section 13 that digitally displays the information, and an operation section 14. The clock device 12 has a normal clock function and a timer function for a well-known timer switch, and each function can be selected and adjusted using the operating section 14.
This is done using each operation button 14a. Further, numeral 15 denotes a heating pattern selection device which is an operating means and is also disposed on the outside of the outer case 1. This device has a plurality of operating buttons 15a, and five types of heating, which will be described later, are controlled by these operating buttons 15a. Patterns, i.e., for "cooking rice porridge", for "scorching", for "cooking", for "double cooking", and "keep warm".
This is for selecting an arbitrary heating pattern among the various heating patterns used for heating, and outputs a pattern selection signal Sp that can specify the selected heating pattern. still,
Reference numeral 16 denotes a display device disposed on the outside of the outer case 1, which has, for example, four indicator lamps 16a, each of which indicates the current operating state by lighting. At this time, the display device 16 is adapted to display the operating states of "rice cooking", "double cooking", "uniform cooking", and "keep warm".

Next, the electrical configuration will be explained with reference to FIGS. 1 and 2. First, in FIG. 2 showing the outline of the electric circuit configuration, 17 is a bidirectional three-terminal thyristor (hereinafter simply referred to as thyristor), and a series circuit between this and the rice cooking heater 6 receives power from the plug 17a. It is connected. Further, the heat-retaining 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 heat-retaining heater 7 are energized in series, and each generates heat with a relatively small heat capacity. The pot 5 is heated with low heat, and when the thyristor 17 is turned on, only the rice cooking heater 6 is energized, which generates heat with a relatively large heat generation capacity, and the pot 5 is heated with high heat. Reference numeral 18 denotes a voltage regulator that constitutes the power supply control means 19 together with the thyristor 17, which is interposed in the current conduction path of the rice cooking heater 6, and reduces the amount of heat generated by suppressing the voltage between the terminals of the rice cooking heater 6. This is a configuration that allows adjustment. Note that the amount of heat generated by the rice cooking heater 6 does not necessarily have to be adjusted by the voltage regulator 18 as described above, and can also be adjusted by, for example, controlling the phase of the thyristor 17 or controlling the on/off duty ratio.

Thus, the voltage regulator 18, together with the thyristor 17 and the clock device 12, is controlled by a control circuit device 20, which is information processing means. As shown in FIG. 1, this control circuit device 20 is configured as a microcomputer including a storage section 21, a time control section 22, and an arithmetic processing section 23, and the storage section 21 includes a thyristor 17 and Five types of programs (described later) for controlling the voltage regulator 18 in a predetermined manner are stored corresponding to the five types of heating patterns. Further, the time control section 22 is provided to receive a 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 section 23 is provided to receive the temperature 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 section 23 as data inputs. reads the program corresponding to the input pattern selection signal Sp from the storage unit 21, controls the thyristor 17 and the voltage regulator 18 based on this read program, the temperature information signal Sd and the time information signal St, and performs the following operations. The heating pattern is configured to obtain a heating pattern corresponding to the program. In addition, the arithmetic processing unit 23
is adapted to also control the clock device 12.

Now, in the following, specific operations performed 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 8 as well as the effects of each heating pattern. In addition, FIG. 5A and FIGS. 6 to 8 show temperature characteristic curves whose horizontal and vertical axes correspond to time T and pan bottom temperature D (℃), respectively, and FIG. The vertical axis shows time T and output P of the rice cooking heater 6, respectively.
A temperature characteristic curve corresponding to (W) is shown.

()……Heating pattern for “cooking rice porridge” (5th
(See figure) A heating pattern for "rice porridge cooking" is selected by the heating pattern selection device 15, and a pattern selection signal by which the heating pattern can be specified is generated.
When Sp is output, the arithmetic processing unit 23 turns on the thyristor 17 and energizes only the rice cooking heater 6 based on the program from the storage unit 21. Therefore, when the pot 5 is heated over high heat, the bottom temperature D of the pot rises relatively rapidly, and the thermistor 11 detects this and outputs the change in its resistance value as a temperature information signal.
Output as SD. Then, when the temperature information signal Sd corresponding to the pot bottom temperature D=80° C. is output at time t ₁ , the arithmetic processing unit 23 operates the voltage regulator 18 in accordance with this to adjust the calorific value of the rice cooking heater 6. Reduce the temperature to about 100 watts and heat pot 5 over low heat. As a result, the pot bottom temperature D is raised relatively slowly. And the pot bottom temperature D is 98
When the temperature reaches °C (time t ₂ ), the arithmetic processing unit 23
A command is issued to the time control section 22 to output the time information signal St after 20 minutes have elapsed. this time
When the above-mentioned time information signal St is output at time t ₃ , which is 20 minutes after t ₂ , the arithmetic processing unit 23 that has received it cancels the operation of the voltage regulator 18 and simultaneously turns off the thyristor 17. The rice cooking heater 6 and the heat-retaining heater 7 are energized in series, and the pot 5 is further heated over a low heat, thereby shifting to an uneven operation. Due to the above-described actions, the rice stored in the pot 5 together with an appropriate amount of water can be cooked into porridge. In particular, during such "rice porridge cooking", the time t ₂ when the pot bottom temperature D reached 98℃
Since the pot 5 is heated at a low heat of about 100 watts from t3 to time _t3 , the cooking liquid in the pot 5 will not boil over due to excessive boiling.

()... Heating pattern for "double cooking" (see Fig. 6) The heating pattern for "double cooking" is selected by the heating pattern selection device 16, and the rice cooking can be specified by the heating pattern. When the pattern selection signal Sp, which is a start command signal, 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 the rice cooking heater 6 cooks the pot 5. Heat over high heat and bring the water in the pot 5 to a boil. During this boiling period, the bottom temperature D of the pot is maintained at approximately 100°C, but when the water in the pot 5 evaporates and is absorbed by the rice, resulting in a so-called dry-up state, the bottom temperature D of the pot rises rapidly. As a result, when the thermistor 11 outputs the temperature information signal Sd corresponding to the pot bottom temperature D=130°C (time t ₄ ), the arithmetic processing unit 23 turns off the thyristor 17 in response to this and shifts to uneven operation. At the same time,
A command is issued to the time control section 22 to output the time information signal St after 5 minutes have elapsed. When the above-mentioned time information signal St is output at time t ₅ , which is 5 minutes after this time t ₄ , the arithmetic processing unit 23 that has received it turns on the thyristor 17 for one minute, and then The medium pot 5 is reheated over high heat to perform so-called double cooking, and then the above-mentioned shading operation is performed. In other words, when a predetermined condition is established that 5 minutes have passed after the end of the rice cooking operation, the double cooking operation is controlled as described above, and as a result, the excess moisture in the cooked rice is removed. The food becomes delicious when it is blown away.

()...Heating pattern for "scorching" (see Figure 7) This heating pattern is almost the same as the heating pattern for "double cooking", and is selected by the heating pattern selection device 16 for "scorching". When a specific heating pattern is selected and a pattern selection signal Sp is output that makes it possible to identify the heating pattern, the ON period of the thyristor 17 during double cooking after time t ₅ is extended to 3 minutes. There are characteristics. Therefore, the time required for reheating the pot 5 over high heat is relatively long, thereby making it possible to brown the cooked rice.

()... Heating pattern for "cooked" rice (see Figure 8) This heating pattern is used when making cooked rice, as seasonings such as soy sauce are added to the pot 5, which tends to cause stickiness. This is to deal with the situation. That is, when the heating pattern selection device 15 selects a heating pattern for "cooking" and outputs a pattern selection signal Sp that can identify the heating pattern, the arithmetic processing unit 2
3 is based on the program from the storage unit 21,
Turning on the thyristor 7 is the same as in each heating pattern described above. After this, the pot 5 exhibits a dry-up state and the bottom temperature D of the pot rises rapidly, and the thermistor 11 indicates the bottom temperature D of the pot at time _t6 .
When the temperature information signal Sd corresponding to =110° C. is output, the arithmetic processing unit 23 turns off the thyristor 17 in response to this and shifts to uneven operation. As described above, a heating pattern suitable for cooked rice can be obtained in which the degree of increase in the pot bottom temperature D is suppressed to a low level, thereby making it difficult for the cooked rice to become scorched.

()... Heating pattern for "keep warm" This heating pattern is for keeping rice etc. warm, and the heating pattern for "keep warm" is selected by the heating pattern selection device 15. pattern selection signal that can identify
When Sp is output, the arithmetic processing unit 23 keeps the thyristor 17 in the off state based on the program from the storage unit 21. This will cause pot 5
A warming operation is performed in which the food is heated over low heat.

In addition, in the above embodiment, when a predetermined period of time has elapsed after the transition to the uneven operation during execution of "cooking rice porridge", "cooking", etc.
1 may be used to make a buzzer or the like sound.

As described above, in this embodiment, the thermistor 11 is provided to detect the temperature of the rice to be cooked through the pot 5, and the temperature information signal Sd from the thermistor 11 is provided.
The present invention is characterized in that a control circuit device 20 is provided which selectively controls other heating patterns, including a heating pattern for cooking rice porridge, etc., in addition to the heating pattern for normal rice cooking. As a result, not only regular rice cooking but also rice porridge cooking etc. can be easily performed. Further, since it is sufficient to simply provide the thermistor 11 to obtain the temperature information signal Sd necessary for such control, there is no need for wasted parts or complication of the structure as in the conventional structure. Moreover, the above temperature information signal
Since Sd is based on the resistance value, which is the easiest to handle as an electrical variable, 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, the temperature detected by the thermistor 11 corresponding to the temperature information signal Sd can be very easily detected. can be compensated. Therefore, it becomes possible to accurately control each heating pattern described above, and the added value of the rice cooker can be easily increased. Further, since a micro switch having a conventional mechanical contact point is not required to detect the temperature of the pot 5, there is no need for any inconvenience caused by wear of the contact point.

〔Effect of the invention〕

According to the present invention, as is clear from the above description, the temperature detection means detects the temperature of the rice to be cooked and outputs a temperature information signal according to the detected temperature, and the energization state of the rice cooker heater for heating the pot. and a power supply control means for controlling the amount of heat generated, a time information signal for timing, the temperature information signal, and a plurality of types of programs including a pre-stored heating pattern for normal rice cooking and a heating pattern for cooking porridge. Information processing means for controlling the power supply control means to selectively obtain a plurality of types of heating patterns for heating the pot, and operation means for arbitrarily selecting the plurality of types of heating patterns. Therefore, various controls including normal rice cooking control and porridge cooking control can be automatically executed with simple operations, and the structure can be simplified and each of the above controls can be made more accurate. It is.

[Brief explanation of drawings]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a block diagram of the electrical configuration, FIG. 2 is a schematic electrical circuit diagram, and FIG. 3 is a partially cutaway front view of the entire device. Figure 4 is a front view of the whole, Figure 5A is a temperature characteristic diagram to explain the effect, Figure 5B is an output characteristic diagram to explain the effect, and Figures 6 to 8 are temperature characteristics to explain the effect. It is a characteristic diagram. In the figure, 5 is a pot, 6 is a rice cooking heater, 7 is a heat retention heater, 11 is a thermistor (temperature detection means), 15 is a heating pattern selection device (operation means), 17 is a bidirectional three-terminal thyristor, and 18 is a voltage regulator. device, 1
9 is a power supply control means, 20 is a control circuit device (information processing means), 21 is a storage section, 22 is a time control section,
23 indicates an arithmetic processing section.

Claims (1)

[Claims] 1. A rice cooker heater for heating a rice cooking pot;
a temperature detection means that is provided to detect the temperature of the rice to be cooked and outputs a temperature information signal according to the detected temperature; a power supply control means that controls the energization state and calorific value of the rice cooking heater; It has a time control unit that generates a time information signal, and a plurality of types of programs including the time information signal, the temperature information signal, and pre-stored heating patterns for normal rice cooking and heating patterns for cooking porridge are based on the above-described program. It is characterized by comprising information processing means for selectively obtaining a plurality of types of heating patterns for heating the pot by controlling the power supply control means, and an operation means for arbitrarily selecting the plurality of types of heating patterns. A rice cooker.