JPH0345216A - Rice boiler with weight sensor - Google Patents

Abstract

PURPOSE:To eliminate erroneous weight measurement upon the closure of a lid and improve the accuracy of weight measurement by detecting the weight of an inner kettle with a weight sensor, using an open/close sensor for detecting the opening or closing of the lid and making the output of the weight sensor invalid with a control part upon the closure of the lid. CONSTITUTION:When placed in a body 1 with the lid 5 thereof open, the inner kettle 8 comes in contact with a rice boiling heater 4 and the weight of the inner kettle 8 acts on a weight detecting part 3 via the heater 4. In this case, the switch 10 of an open/close sensor 5 is closed, and a control part 11 makes the output of a weight sensor 2 valid. weight resulting from the deduction of the weight of the inner kettle 8 from the aforesaid output is detected as the weight of a boiled article. Then, when the lid 5 is closed, an inner lid 7 presses the inner kettle 8, and the weight detecting part 3 is subjected to other weights than the inner kettle 9 and the boiled article. Before the contact of the inner lid 7 with the inner kettle 8, however, the switch 10 of the open/close sensor 9 opens. when the aforesaid switch 10 opens, the control part 11 judges that the output of the weight sensor 2 is invalid. It follows, therefore, that erroneous weight detection due to the closure of the lid 5 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rice cooker equipped with a weight sensor that detects the amount of rice to be cooked and controls the rice cooking.

Conventional Technology As an example of a conventional rice cooker with a weight sensor of this type, the weight of the inner pot and the rice to be cooked in the inner pot is applied to a compression spring on the bottom frame, and is compressed proportionally, and the electrode plate on the bottom frame is compressed. It moves downward by the displacement of the spring, and the capacitance of the electrode plate changes, which is converted into a frequency change through the oscillation circuit and input to the microcontroller.
There are devices that control the rice cooking by determining the amount of rice to be cooked by comparing it with data set in advance in a microcomputer. (For example, Japanese Unexamined Patent Publication No. 59-201.24) Another example is a weight sensor that detects the weight of the inner pot as a voltage change, and a weight detection section (inner pot measuring section) that transmits the weight of the inner pot to the weight sensor. ) and a lid opening/closing sensor (link mechanism) that moves the weight detection unit up and down in conjunction with the opening and closing of the lid.
It has a rice cooking control section, etc. When the lid is opened, the weight detection section is pushed up to measure the amount of rice, determine whether the amount of water is appropriate, and display it, and when the lid is closed, the weight detection section is lowered and the rice cooking control begins. There is something I tried to do. (For example, JP-A-60-150
720 Publication) Problems to be Solved by the Invention In the device that detects the weight by changing the capacitance of the electrode plate, the weight including the main body and the inner pot is detected to measure the weight of the rice to be cooked. Therefore, the total weight becomes large, and minute changes in weight within the inner pot cannot be detected with high accuracy. For example, if the main body weighs 2700 g and the inner pot weighs 300 g, the weight will always be 30 g.
A load of 00 g is applied.

In this configuration, the Log load change in the inner pot is 0.3% (1
There was a problem in that it was only a change in the weight sensor output (0/300040.3%) and was difficult to detect.

On the other hand, the device that detects the weight of the inner pot as a voltage change has a structure that only detects the weight of the inner pot, so it is difficult to detect the weight of the inner pot as a voltage change.
10 g load change is 3% (10/300043%)
The amount of change is 10 times that of the above example, which is advantageous in terms of accuracy. This weight sensor changes depending on the weight (
The displacement amount is converted into an electrical signal, and the larger the amount of displacement, the more accurately it can be converted into an electrical signal. For example, 1kg
A displacement of 10 mm can be converted into an electrical signal more accurately and easily than a displacement of 1 mm. However, with this configuration, if the position of the inner pot changes greatly due to the weight, the lid may not close, or even if it is closed, the distance between the lid and the inner pot will become small. The lid is raised so that a large amount of displacement can be obtained, and when the lid is closed, it returns to its normal position.

However, it has a complicated structure, resulting in problems such as the rice cooker itself becoming large, and the lid being difficult to open and close because the force used to open the lid lifts the inner pot.

Means for Solving the Problems The present invention has been made to solve the above problems.1 A weight sensor having a weight detection section is provided inside the main body,
A rice cooking heater is attached to the weight detection section, the inner pot is brought into contact with the rice cooking heater, an opening/closing sensor is provided to detect opening/closing of the lid covering the opening of the inner pot, and the weight sensor and the opening/closing sensor are connected to the control section. When the lid is closed, the inner pot and the lid come into contact with each other and the correct load cannot be applied to the weight sensor, so the controller is designed to control the output of the weight sensor at this time.

Function: With the above structure, the weight sensor detects the weight of the inner pot via the rice cooking heater and the weight detection section only when the lid is opened.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a rice cooker with a weight sensor according to an embodiment of the present invention, FIG. 2 is a state diagram of the open/close sensor when the lid is open, and FIG. 3 is a state diagram of the open/close sensor when the lid is closed.

Its configuration includes a weight sensor 2 inside the main body 1.

A rice cooking heater 4 is attached to the weight detection section 3 of the weight sensor 2. A lid 5 is provided on the main body 1 so as to be openable and closable, and an inner lid 7 is attached to the lid 5 via an elastic bushing 6. An inner pot 8 is removably housed in the main body.

When the lid 5 is closed, the inner lid 7 and the upper end of the inner pot 8 come into contact. The bush 6 is deformed by this contact, and has the effect of strongly pressing the inner lid 7 against the inner pot 8 due to its elasticity. An opening/closing sensor 9 is attached near the attachment of the lid 5 to the main body 1, and the switch IO is configured to close when the lid 5 is opened. The main body 1 is also provided with a control section 11 for controlling rice cooking, and a weight sensor 2 and an opening/closing sensor 9 are connected thereto.

The operation of this embodiment having the above configuration will be explained.

When the inner pot 8 is stored in the main body 1 with the lid 5 open, the inner pot 8 comes into contact with the rice cooking heater 4, and the weight of the inner pot 8 is applied to the weight detection part 3 via the rice cooking heater 4. At this time, the switch 10 of the opening/closing sensor 9 is closed, and the control section 11 enables the output of the weight sensor 2, and detects the weight obtained by subtracting the weight of 8 inner pots from this output as the weight of the rice to be cooked. Next, when the lid 5 is closed, the inner lid 7 pushes the inner pot 8, so the weight of the object other than the inner pot 8 and the rice to be cooked is added to the weight detection section 3, but the lid 7 opens and closes before the inner lid 7 comes into contact with the inner pot 8. Switch 10 of sensor-9 opens. The control unit 11 is configured to invalidate the output of the weight sensor 2 when the switch 10 of the opening/closing sensor 9 is opened, so that it is possible to prevent an incorrect weight from being detected due to the lid 5 being closed.

In this embodiment, the switch 10 is attached to the main body 1 as the opening/closing sensor 9, but any sensor may be used as long as it can detect the opening/closing of the lid 5, and even if it is provided on the lid 5, the same effect can be obtained.

Effects of the Invention According to the present invention, the weight of the inner pot is detected by a weight sensor, the opening/closing sensor detects the opening/closing of the lid, and the control section disables the output of the weight sensor when the lid is closed. Because of this, there is no need for a complicated mechanism, there is no need to accidentally measure the weight when the lid is closed, the weight detection accuracy is high, the lid is not heavy to open and close, and the rice cooker itself can be made compact, etc., which has great effects. It is.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a rice cooker with a weight sensor showing an embodiment of the present invention, Fig. 2 is a state diagram of the open/close sensor when the lid is open, and Fig. 3 is a state diagram of the open/close sensor when the lid is closed. FIG. 1...Main body, 2...Weight sensor 3...
・Weight detection unit, 4... Rice cooking heater 5... Lid, 8... Inner pot, 9... Open/close sensor,
11...control unit.

Claims (1)

[Claims] A weight sensor (2) is provided inside the main body (1), and a rice cooking heater (4) is connected to the weight detection part (3) of the weight sensor (2).
), and the inner pot (8) that accommodates the rice to be cooked is attached to the main body (1).
), the inner pot (8) comes into contact with the top surface of the rice cooking heater (4), and the weight of the inner pot (8) is detected by the weight detection part (
3), and the upper opening of the inner pot (8) is connected to the lid (
5), in which a portion of the lid (5) is in contact with the inner pot (8), is equipped with an opening/closing sensor (9) for detecting opening/closing of the lid (5);
The weight sensor (2) and the open/close sensor (9) are connected to the control unit (11) that controls rice cooking, and the control unit (11) switches the weight sensor (2) when the open/close sensor (9) indicates “lid closed”. ) is disabled.