JPH01212512A - Rice cooker - Google Patents

Abstract

PURPOSE:To enable detection of a water level through simple control, by a method wherein a support device having an ultrasonic sensor and a position detecting part are mounted to the upper part of a body or the under surface of a cover, and the position detecting part and the ultrasonic sensor are connected to a control part mounted to the body or the inside of a cover. CONSTITUTION:After rice is placed in an inner port 3 and is washed, water is placed to contain the pot in a body 1. With a support device 4 rotated, the contact of the switch of a position detecting part 7 is closed, a control part 8 sends a signal to an ultrasonic sensor 6 to start clocking. By means of a signal from the control part 8, the piezoelectric element of the ultrasonic sensor 6 oscillates ultrasonic waves. From a time in which ultrasonics are reciprocated between the ultrasonic sensor 6 and a water surface, the position detecting part 7 determines the position of a water surface, and the control part 8 displays the level thereof on a display part 9. This display enables detection of the altitude of the level.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rice cooker that detects the water level of water and notifies the user of the water level.

2. Description of the Related Art Conventional rice cookers have a water level line engraved on the side of the inner pot to indicate the appropriate water level, and the user adjusts the amount of water by adjusting the water level to match the desired amount of rice to be cooked. There is also a device that measures the weight of the inner pot and reports the water level to improve the convenience of use. (For example, JP-A-59-2012
Problems to be Solved by the Invention In the conventional method using the engraved water level line, the water level line engraved on the inner side surface of the inner pot is viewed diagonally from above, which makes it difficult to see. . If you make the boundary between the engraved line and other surfaces clear in order to make it easier to see, the rice will become more sticky and difficult to clean, so it is necessary to connect the engraved line and other surfaces smoothly, and the border will not be clear. It was hard to see.

Also, since the inside of the inner pot was coated with fluororesin to prevent rice from sticking, it was not possible to color the water level line.Also, in the case of a device configured to measure the weight and notify the water level, there is no measuring means. There was a problem with the large-scale configuration.

Means for Solving the Problems The present invention has been made to solve the above problems, and includes a support device that moves the tip to approximately the center of the top surface of the inner pot, and a position detection section that detects the position of the support device. An ultrasonic sensor is installed above the pot, and the tip of the support device is equipped with an ultrasonic sensor that emits ultrasonic waves toward the inner bottom of the inner pot and receives reflected waves.1 Control unit that connects a position detection unit and an ultrasonic sensor inside the main body or lid. It has a section.

Operation With the above configuration, the support device and position detection unit provided above the inner pot move the ultrasonic sensor to the approximate center of the top surface of the inner pot, detect the position of the support device, and detect the position of the support device at the tip of the support device. The installed ultrasonic sensor emits ultrasonic waves toward the inner bottom of the inner pot and receives the reflected waves reflected from the water surface inside the inner pot.The position detection unit and the control unit connected to the ultrasonic sensor Upon receiving the output signal from the position detection section, the ultrasonic sensor transmits ultrasonic waves and measures the time it takes to receive the reflected waves to detect the water level.

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

FIG. 1 is a perspective view of a rice cooker according to an embodiment of the present invention, FIG. 2 is a front view of the same display section, and FIG. 3 is a perspective view of a rice cooker according to another embodiment. Fig. 4 is a block circuit diagram of an ultrasonic sensor configured to transmit and receive ultrasonic waves with a single element, and Fig. 5 is a block circuit diagram of an ultrasonic sensor configured with dedicated elements for transmitting and receiving ultrasonic waves. FIG. 3 is a constructed block circuit diagram.

In the figure, 1 is the main body, 2 is the lid, 3 is the inner pot, 4 is the support device, 5 is the fulcrum, 6 is the ultrasonic sensor, 6-1 is its transmitter (speaker), and 6-2 is the receiver ( Mike), 7
8 is a position detection unit, and 8 is a control unit (in Fig. 1, the main body 1 and the third
(In WA, it is provided inside the lid 2) 1.9 is the display section, 10
11 is an amplifier circuit, 11 is a filter circuit, and 12 is a waveform shaping circuit.

Its structure is such that a lid 2 is attached to the main body 1 so as to be openable and closable, and an inner pot 3 is housed in the main body 1 in a detachable manner. l
When i2 is closed, the upper opening of the inner pot 3 is closed. In FIG. 1, a support device 4 is provided at the upper end of the main body 1, and is manually rotated about a fulcrum 5 to move the inner pot 3 upward.

An ultrasonic sensor 6 using a piezoelectric element is attached to the opposite side of the support device 4.
When stored, the support device 4 and the position detection section 7 are in contact with each other and the switch contact is open. When the supporting device 4 is moved above the inner pot 3, the contact with the position sensing section 7 is released and the switch contact is closed. (In FIG. 3, the supporting device 4, the fulcrum 5, and the position detecting section 7 are provided on the lid 2 instead of the main body 1.) The position detecting section 7 is connected to the control section 8, and 1. Electric signals are transmitted to the control unit 8 by opening and closing the switch contacts.The control unit 8 includes an ultrasonic sensor 6 and a display unit 9.
is also connected, and the electric wire is ↑,? I can get over it.

I will explain one example of the above-mentioned compositional ability) Naru Honbei.

After the user puts rice in the inner pot 3 and washes the rice, pours water appropriately and stores it in the main body 1, and then rotates the support device 4.
・1・: The contact of the switch of the position detection unit 7 is closed and the control unit 8,
The electricity and signals sent to the controller 8 change and convert into ultrasonic waves,
Send a transmission signal to the sensor 611. Start timing at the same time. Control unit 8. The piezoelectric element of the ultrasonic sensor 6 is slightly vibrated by the half-wave signal, and an ultrasonic wave is emitted.

The emitted ultrasonic waves are transmitted through the air toward the bottom of the inner pot 3 and reach the water surface inside the inner pot 3. The propagation power, speed C, and density ρ9 product pc of sound waves differ greatly between air and water. general,
The bigger 4G is! Reflection occurs at the ultrasonic wave, and in this case, the ultrasonic wave is reflected from the water surface and returns to the ultrasonic sensor 6 as one reflected wave. At this time, the slight vibrations caused by the previous transmitted signal have subsided, and the pressure of this reflected wave causes the piezoelectric element of the ultrasonic sensor 6 to vibrate slightly and generate an electric signal. Control unit 8
This signal is amplified by an amplifier circuit 10, noise components outside the transmitted frequency band are cut by a filter circuit 11, and a waveform is shaped into a pulse by a waveform shaping circuit 12. Timing is terminated by inputting this pulse. The measured time t is the time during which the ultrasonic waves travel back and forth between the ultrasonic sensor 6 and the water surface, and the distance between the ultrasonic sensor 6 and the water surface can be calculated from the measured time t and the speed of sound C. That is, D=C-t xi/2. Because the distance between the ultrasonic sensor 6 and the bottom of the inner pot 3 is constant.

The position of the water surface can be determined from the distance. Control unit 8
This water level is displayed on the display section 9 as shown in FIG. The user can know the height of the water level from this display, and can increase or decrease the amount of water using a tap or the like.

The control section 8 repeats the water level detection operation and displays the display as long as the output of the position detection section 7 indicates that the support device 4 is above the inner pot 3, so that the user can adjust the water level correctly. As shown in FIG. 4, the ultrasonic sensor 6 has been described as having one element for transmitting and receiving, but as shown in FIG. 5, the transmitter 6-1. Even if the receiving element 6-2 and the receiving element 6-2 are constructed with separate elements, the same effect can be obtained.

Although the present invention uses the ultrasonic sensor 6 and the control unit 8 to detect the water level, the minimum configuration is required. It also has the same effect.

Effects of the Invention As described above, in the present invention, a support device and a position detection section are provided on the upper part of the main body or the lower surface of the lid, an ultrasonic sensor is provided on the support device, a control section is provided inside the main body or the lid, and the position detection section is provided on the control section. Since the detection part and the ultrasonic sensor are connected, the water level can be determined with simple operation, and the water level can be set accurately, which is highly effective in improving usability and rice cooking performance.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a rice cooker showing one embodiment of the present invention;
The figure is a front view of the display unit, Figure 3 is a perspective view of a rice cooker with another embodiment, and Figure 4 is an ultrasonic sensor configured to transmit and receive ultrasonic waves with one element. Block Circuit Diagram FIG. 5 is a block circuit diagram in which an ultrasonic sensor is composed of elements dedicated to transmitting and receiving ultrasonic waves, respectively. 1...Main body, 2...Lid, 3...Inner pot,
4... Support device, 6... Ultrasonic sensor, 7... Position detection section, 8... Control section.

Claims (4)

[Claims] (1), a main body (1), an inner pot (3) that is removably housed in the main body (1), and a lid (2) that covers the upper opening of the inner pot (3).
) and a heater that heats the inner pot (3) in close contact with the inner pot (3). A device (4) and a position detection unit (7) for detecting the position of the support device (4) are provided, and ultrasonic waves are emitted at the tip of the support device (4) toward the inner bottom surface of the inner pot (3). A rice cooker characterized in that it is provided with an ultrasonic sensor (6) for receiving and receiving information, and further has a position detection section (7) and an ultrasonic sensor (6) connected to a control section (8). (2) The rice cooker according to claim 1, wherein the ultrasonic sensor (6) is configured to transmit and receive ultrasonic waves with one element. (3) The rice cooker according to claim 1, characterized in that the ultrasonic sensor (6) is constructed with dedicated elements for transmitting and receiving ultrasonic waves, respectively. (4) The rice cooker according to claim 1, wherein the control section (8) is provided inside the main body (1) or the lid (2).