JPH0552732B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to cooking appliances such as rice cookers, boilers, ovens, etc., for cooking foods to be heated in general households.

BACKGROUND ART In a conventional cooker of this type, a microcomputer 1 and peripheral circuits are employed, as in the example of a rice cooker shown in FIGS. 4 and 5. The microcomputer 1 shown here is CPU, ROM,
It is a so-called one-chip microcomputer consisting of RAM, input/output ports, etc. 2 is a first temperature sensor attached to the center of the bottom of the bottomed cylindrical pot 3; 4 is a second temperature sensor attached to the lid 5 that closes the opening of the bottomed cylindrical pot 3; The first temperature sensor 2 and the second temperature sensor 4 are connected to an input port of the microcomputer 1 via A/D converters 6 and 7. As a result, the temperature signals from the first temperature sensor 2 and the second temperature sensor 4 are converted into binary codes and read into the microcomputer 1. Reference numeral 8 denotes a start switch, and an input is made to the microcomputer 1 to determine whether or not the start switch 8 has been pressed. Reference numeral 9 denotes an AC power source, and a series circuit of a heater 10 and a relay contact 11 for heating food such as ice and water stored in the pot 3 is connected to the AC power source 9, and an output port of the microcomputer 1 is connected to the AC power source 9. The signal from transistor 12
The relay contacts 11 are opened and closed by passing current through the relay coil 13 through the relay coil 13. 14 is a DC power supply for operating the circuit described above.

In a cooker configured in this way (a rice cooker is shown here), when food to be heated such as rice or water is placed in the pot 3 and the start switch 8 is pressed,
Start energizing the heater 10, and with the signals from the first temperature sensor 2 and the second temperature sensor 4,
According to a sequence stored in the microcomputer 1, the heater 10 is repeatedly energized and de-energized to complete the cooking. and,
If the first temperature sensor 2 or the second temperature sensor 4 is disconnected, the heater 10 is not energized even if the start switch 8 is pressed.

In addition, some cookers use a liquid crystal display or light emitting diode to show the cooking process, but if the temperature sensor is disconnected, the heater will not be energized and the liquid crystal display will It was configured so that it did not display any information using light emitting diodes or light emitting diodes.

Problems to be Solved by the Invention However, in such a conventional configuration, it is difficult to determine whether the microcomputer or peripheral circuit is damaged and the circuit does not operate, or whether the temperature sensor is disconnected. I couldn't do it. In addition, because temperature sensors are often connected to circuits with connectors, simple disconnection of the connector often occurs, and even in this case, it is impossible to determine whether it is a circuit failure, and if there are multiple temperature sensors. As a result, simple connector disconnections and contact failures occur more frequently, which takes time to analyze defects in processes and in the market.As a result, costs increase due to increased man-hours and repair times increase, resulting in problems for users. There was a problem that caused trouble.

The present invention solves these problems,
Detects disconnection in each of multiple temperature sensors,
It is an object of the present invention to provide a cooking appliance that can immediately distinguish between circuit failures and improve serviceability by displaying each of them.

Means for Solving the Problems In order to solve the above problems, the cooker of the present invention includes a heater that heats the food to be heated, and a plurality of temperature sensors that directly or indirectly detect the temperature of the food to be heated. a sensor, and a plurality of disconnection detection means for detecting disconnection of each of the plurality of temperature sensors;
The apparatus includes a plurality of disconnection display means for displaying the disconnection of each of the plurality of temperature sensors based on the outputs of the plurality of disconnection detection means.

Effects According to the above configuration, it is possible to detect each disconnection of a plurality of temperature sensors and display each disconnection, so it is possible to immediately determine that the circuit itself is malfunctioning, and as a result, the connector in the process Insertion failures and disconnection of temperature sensors can be detected immediately, allowing for quick and smooth failure analysis. Furthermore, even if the temperature sensor is disconnected or the temperature sensor connector is disconnected while the user is using it, this can be easily detected.
It becomes possible to shorten the repair period and improve serviceability. With such a simple configuration, it is possible to provide a cooking appliance that can efficiently perform failure analysis in the process and improve serviceability.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 3. Note that in FIGS. 1 to 3, the same parts as in FIGS. 4 and 5 shown in the conventional example are given the same numbers, and the explanation thereof will be omitted.

Fig. 1 shows a liquid crystal display element (hereinafter referred to as LCD) of a rice cooker in an embodiment of the present invention, 15 is the LCD, and Fig. 1a shows the display when the LCD 15 is fully lit; Figure 1 b shows the display when the first temperature sensor 2 of the LCD 15 is disconnected, and Figure 1 c shows the display when the first temperature sensor 2 of the LCD 15 is disconnected.
The display when the second temperature sensor 4 of the LCD 15 is disconnected is shown.

FIG. 2 shows a circuit diagram of a rice cooker according to an embodiment of the present invention, which is composed of a microcomputer 1 and peripheral circuits. The A/D converters 6 and 7 are composed of comparators and resistors, and input temperature data from the first temperature sensor 2 and the second temperature sensor 4 to the microcomputer 1. The LCD 15 is connected to the output port of the microcomputer 1.

Next, the operation of the rice cooker configured as above will be explained. Figure 3 shows the contents of microcomputer 1.
This is a flowchart of the program stored in the ROM, and its operation will be explained according to the steps of the program shown in this flowchart.

First, in step 1, the temperature of the first temperature sensor 2 is measured, in step 2, the temperature of the second temperature sensor 4 is measured and stored, and in step 3, the temperature of the second temperature sensor 4 is measured and stored.
It is determined whether or not the first temperature sensor 2 is disconnected. If not, the process proceeds to step 4, where it is determined whether the second temperature sensor 4 is disconnected. If it is not disconnected, Proceed to step 5, and determine whether the rice cooking is finished.
If the rice has been finished, in step 6 the rice is cooked according to the rice cooking sequence stored in the ROM, and the process returns to step 1. If it is determined in step 5 that the rice cooking has been completed, the rice is kept warm in accordance with the warming sequence stored in the ROM in step 7, and the process returns to step 1. If it is determined in step 3 that the first temperature sensor 2 is disconnected, only "sensor 1" is displayed on the LCD 15 in step 8, and then the process proceeds to step 9, where the power to the heater 10 is stopped, and the process proceeds to step 1. return. Furthermore, if it is determined in step 4 that the second temperature sensor 4 is disconnected, the process proceeds to step 10.
Display only "sensor 2" on LCD 15 and proceed to step 9.

In this way, each disconnection of a plurality of temperature sensors is detected and each disconnection is displayed individually, so it can be quickly determined that it is a circuit failure.

Effects of the Invention As described above, according to the present invention, each disconnection of a plurality of temperature sensors is detected and each disconnection is displayed, so that it can be immediately determined whether the circuit itself is malfunctioning. As a result, failures such as incorrect connector insertion or disconnection of temperature sensors during the process can be detected immediately, allowing failure analysis to be carried out quickly and smoothly. Furthermore, even if the temperature sensor is disconnected or the temperature sensor connector is disconnected during use, the user can easily tell, which shortens the repair time and improves serviceability. It is something that can be done.

[Brief explanation of the drawing]

Figures 1a, b, and c are front views of the liquid crystal display of a rice cooker showing an embodiment of the present invention, Figure 2 is a circuit diagram of the rice cooker, and Figure 3 is an example of a program for the rice cooker. FIG. 4 is a circuit diagram of a conventional rice cooker, and FIG. 5 is a cutaway side view of the rice cooker. 1...Microcomputer, 2...First temperature sensor, 4...Second temperature sensor, 6,7
... A/D converter, 10 ... heater, 15 ... liquid crystal display element.

Claims (1)

[Claims] 1. A heater that heats the food to be heated, a plurality of temperature sensors that directly or indirectly detects the temperature of the food to be heated, and a plurality of disconnection detection means that detects disconnection of each of the plurality of temperature sensors;
A cooking appliance comprising a plurality of disconnection display means for displaying disconnection of each of the plurality of temperature sensors based on the outputs of the plurality of disconnection detection means.