JPH0137926B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric jar rice cooker used in general households that incorporates a timer that allows the rice cooking start time to be set.

Structure of conventional example and its problems In recent years, in electric jar rice cookers used in general households that have both heat retention and rice cooking functions, the rice cooking process is controlled by a microcomputer according to a certain program, and the thermal power, etc. It has been proposed that the rice be cooked while being adjusted.

Hereinafter, the conventional microcomputer-equipped jar rice cooker mentioned above will be explained with reference to the drawings.

FIG. 1 shows an electric circuit diagram of the microcomputer-equipped jar rice cooker. In Figure 1,
1 is a power plug, 2 is a power switch, 3 is a temperature fuse, 4 is a capacitor for noise reduction, 5 is a lid heater, 6 is a lower heater, and 7 is a side heater.
8 is a relay switch for controlling the power of the lower heater 16; 9 is for detecting the start of rice cooking and the completion of rice cooking;
The rice cooking switch 10 is operated by a heat-sensitive element placed in contact with the bottom of the pot, and 10 is a power semiconductor for controlling the series circuit of each heater during warming and the power of the lower heater and side heater during cooking.

11 is a microcomputer that stores a rice cooking program, 12 is a Zener diode that creates a constant voltage power supply for the microcomputer 11, and 13
1 is a relay coil, 14 is an output section for operation display, etc., 1
5 is a temperature input section from a heat sensitive element in contact with the bottom of the pot. 16, 17, 18 are transistors, 1
9, 20 and 21 are diodes, 22 and 24 are resistors, and 23 and 25 are capacitors, respectively.

The operation of the jar rice cooker configured as above will be explained below. First, when cooking rice, plug the power plug 1 into the power source, turn on the power switch 2, and then turn on the rice cooking switch 9. At this time, the contacts of the rice cooker switch 9 are 9a, 9
c is connected.

Further, the capacitor 23 is charged through the diode 19 and the resistor 22. This power supply energizes the drive control section including the microcomputer 11 and starts operation. The output of the microcomputer 11 is amplified by the transistor 16 and turns on the power semiconductor 10. Similarly, the relay coil 13 is driven by the transistor 17, the contact of the relay switch 8 is turned to the 8b side, and the lower heater 6 is energized.

In the initial stage of rice cooking, the temperature input section 15 detects the pot temperature and energizes the lower heater 6 and the side heater 7 to keep the pot temperature constant, thereby forming a submergence process. After a certain period of time has elapsed, the lower heater 6 and side heater 7 are fully energized. During this time, the amount of rice cooked is detected by detecting how the pot temperature rises. When the pot temperature exceeds a predetermined temperature, the lower heater 6 and the side heater 7 are turned on. Side heater 7
Controls the energization of the fire and adjusts the firepower. After this, the heat-sensitive element placed at the bottom of the pot detects the completion of rice cooking and the process continues until the switch 9 is switched to the 9b side.

Next, a description will be given of the warming operation when the rice cooking switch 9 is switched from the 9a side to the 9b side. When the switch is turned on to the 9b side, a half-wave current of the power supply flows through the resistor 24 and the diode 20 to the transistor 18 as a base current. In the base circuit, half-wave current is smoothed by capacitor 25,
The collector output of the transistor 18 becomes a DC signal, which is input to the microcomputer 11 to perform a heat-retaining operation. In this case, temperature input section 1
Depending on the pot temperature from 5, the power semiconductor 10 is turned on and off, and the lid heater 5, lower heater 6 and side heater 7 are turned on and off.
The series circuit is energized to perform heat retention control operation. Note that each operation mode is displayed on the display section 14.
This is done by emitting light from LEDs, etc.

However, in the circuit configuration as described above, the control circuit and the heater and contact circuits are connected in a complicated manner, so that when a timer is provided, the connection cannot be easily made. This is because if a timer is installed in the power supply path and, for example, switch 2 is used as a contact point of the timer, the power will be turned on after the time set by the timer has elapsed.
In that case, regardless of whether the rice cooking switch 9 is turned on or not, the power is turned on after the set time of the timer has elapsed. Therefore, if the user forgets to turn on the rice cooking switch and sets the timer, the rice will simply keep warm after the timer set time has elapsed, causing the problem that the rice will not cook. It is.

Furthermore, if the rice cooking switch is turned on and rice cooking is started after the timer set time has elapsed, the rice cooking program of the microcomputer is provided with a submersion process, so the submergence process is always performed. Soaking can be done by keeping water and rice in a pot for several hours, but this also has the disadvantage that the rice cooking time is lengthened because the soaking process is always performed.

Purpose of the Invention In view of the above-mentioned conventional drawbacks, the present invention provides a specific circuit configuration in which a timer is added to a jar rice cooker equipped with a drive control circuit including a microcomputer, and changes the soaking process by changing the set time of the timer. The purpose of this study is to provide a concrete method for achieving this goal.

Structure of the Invention In order to achieve the above object, the jar rice cooker with a timer of the present invention includes a main body, a lid provided on the top surface of the main body so as to be openable and closable, and a pot detachably housed in the main body. a lower heater provided on the inner bottom of the main body; a side heater provided on the inner surface of the main body;
a lid heater provided on the lower surface of the lid, a temperature sensing element that senses the temperature of the pot, a heater drive control section comprising a microcomputer and a power control means;
The common contact of the timer switch is connected to the common contact of the rice cooker switch, and the two contacts of the timer switch are connected to the power supply and the power terminal of the heater drive control section, respectively, and one contact of the timer switch is connected to the power supply terminal of the heater drive control section. is connected to the coil of the timer motor, and a switch linked to the dial of the timer inputs an input signal corresponding to the set time of the timer to the microcomputer, and is configured to switch the soaking time at the initial stage of rice cooking into at least two stages. This is what I did.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an electric circuit diagram of a jar rice cooker with a timer according to an embodiment of the present invention. In Fig. 2, 31 is a power plug, 32 is a power switch, 33 is a temperature fuse,
34 is a capacitor for noise reduction, 35 is a lid heater provided on the lower surface of the lid, 36 is a lower heater provided on the inner bottom of the main body, and 37 is a side heater provided on the inner side of the main body.

38 is a timer motor, 39 is a timer switch, 40 is a rice cooking switch for starting and detecting the completion of rice cooking, 41 is a relay switch, and 42 is a relay coil. 43 is a power semiconductor for controlling the heater, 44 is a switch linked to a timer dial, and is input to the microcomputer 46 via a self-holding circuit 45. 47 is an output display section, 4
Reference numeral 8 denotes a temperature input section consisting of a heat-sensitive element in contact with the pot. 49, 50, 51 are transistors, 5
2, 53, 54 are diodes, 55 is a Zener diode for constant voltage power supply, 56, 58 are resistors, 5
7 and 59 are capacitors, and 60 is a display lamp.

The operation of the circuit configuration of the jar rice cooker with timer configured as described above will be explained below.

First, when the timer is at the zero time point, the timer switch 39 is connected to 39c-39b-39d, and when the rice cooking switch 40 is turned on to set the rice cooking mode and the contacts 40a to 40c are connected, the microcomputer 46 The power supply of the drive control circuit including the resistor 56, the diode 52, the capacitor 57, the Zener diode 55, and the resistor 5
8. It is made by capacitor 59 etc., and according to the rice cooking program, relay 41 and power semiconductor 4
3 and energizes the lower heater 36 and side heater 37 to start cooking rice.

Thereafter, a heating process using small power for submersion, automatic rice cooking amount determination, etc. are performed using a signal from the temperature input section 48, and each power control means performs on/off control. When rice cooking is finished, the rice cooking switch 40 switches to 4.
The connection is switched to 0c-40b, and the heating operation is started after the additional cooking process and the uneven cooking process.

Next, when the timer is set, the switches 44 linked to the timer dial are set to 44a-44c.
is connected. At this time, if the rice cooking switch 40 is in the warming mode, the timer motor 38 is not energized, and therefore the indicator lamp 60 connected to both ends of the coil of the timer motor 38 is not lit either.

On the other hand, turn on the rice cooking switch 40 and
When -40c is connected, the timer motor 38 is connected to the power source through the lid heater 35 and lower heater 36, which have relatively low impedance, and the timer is operated and the timer set indicator lamp 60 is also lit. Also, contact 3 of timer switch 39
9b, 39d, etc. are separated, power is not supplied to the control circuit, only the microcomputer 46 operates, and the problem that the program progresses without permission occurs.

Furthermore, a switch 44 provided in conjunction with the timer dial provides an input signal to the microcomputer 46 according to the set time of the timer, and depending on the set time of the timer, the water soaking time at the initial stage of rice cooking can be changed to at least two stages. It is configured to switch to

3 and 4 show the specific structure of the switch 44 portion.

In FIG. 3, 80 is a switch case, 81 is a conductor with a notch attached to the switch case, 82 is a contact, 83 is a timer knob, and 84 is a conductor provided to be in contact with the contact 82. 85 is a contact electrically connected to the conductive part 84, and 86 is a hole into which the timer shaft and knob fit. In FIG. 4, reference numeral 87 indicates a timer shaft, and reference numeral 88 indicates a main body of the timer.

The switch 44 includes contacts 82 and 85, and a conductive part 8.
1 and 84, when the setting angle of the timer is within 90 degrees, it is off because the conductive part 81 is cut out, and when it is 90 degrees or more, it is on.

The situation at this time is shown by a characteristic line 89 in FIG. FIG. 6 shows a specific configuration of the self-holding circuit 45, and 90 is a switch that operates in conjunction with the rice cooking switch 40, and is closed in the rice cooking mode. 91 is
NPN transistor, 92 is a bypass capacitor for preventing malfunction, 93 is PNP transistor, 9
4 is a battery.

When the switch 44 is turned on by turning the timer 90 degrees or more, the transistor 91 is turned on.
The transistor 93 is also turned on, the output of the self-holding circuit becomes high level, and this signal is input to the microcomputer 46. Also, this retention
When the rice cooking is finished, the switch 90 is opened in conjunction with the rice cooking switch 40, so that the rice cooking switch 90 is released.

On the other hand, the setting angle for the 12-hour timer is 90°C.
When the timer is set within the following three hours, there is no output from the switch 44, and therefore the self-holding circuit 4
Since there is no output from step 5, the microcomputer 46 increases the time for the soaking process at the initial stage of rice cooking to around 20 minutes, and when the rice is cooked for more than 3 hours, the output from the switch 44 is generated, and the time for the soaking process is set longer than this. It becomes possible to operate so as to keep it short.

In addition, since the amount of rice to be cooked is automatically determined based on the rising gradient of the pot temperature during rice cooking, it is necessary to initialize the pot temperature, and the soaking time is not set to zero.

Effects of the Invention As described above, by connecting the timer contacts as in the present invention, if the timer operation and timer set display are limited to when the rice cooking switch is turned on, the user can start the rice cooking operation after the timer setting time has elapsed. In addition to being able to reliably perform this process, the rice cooking is also controlled by a microcomputer, making it possible to cook fluffy and delicious rice.

Furthermore, since it is equipped with a timer, it is easier to use and has the advantage that the soaking process time is automatically adjusted according to the time set on the timer, so there is no need to waste time.

[Brief explanation of drawings]

Figure 1 is an electric circuit diagram of a conventional jar rice cooker using a microcomputer, Figure 2 is an electric circuit diagram of a jar rice cooker with a timer according to an embodiment of the present invention, and Figure 3 is an embodiment of the present invention. Fig. 4 is a cross-sectional view showing the structure of the switch part, Fig. 5 is a characteristic diagram showing the operating status of the switch,
FIG. 6 is a circuit diagram showing a specific configuration of the self-holding circuit in the rice cooker.

Claims (1)

[Claims] 1 a main body, a lid provided on the top surface of the main body so as to be openable and closable, and a pot removably housed in the main body;
a lower heater provided on the inner bottom of the main body, a side heater provided on the inner surface of the main body, a lid heater provided on the lower surface of the lid, a temperature sensing element for sensing the temperature of the pot, a microcomputer, and It is equipped with a heater drive control unit consisting of power control means and a timer motor, and the common contact of the timer switch is connected to the common contact of the rice cooking switch, and the two contacts of the timer switch are connected to the power supply terminal and the power supply terminal of the heater drive control unit, respectively. Furthermore, one contact of the timer switch is connected to the coil of the timer, and the switch linked to the dial of the timer inputs an input signal corresponding to the set time of the timer to the microcomputer, and calculates the soaking time at the initial stage of rice cooking. A jar rice cooker with a timer configured to switch between at least two stages.