JPH11113738A - Water level detector of rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically and precisely execute water level detection during a rice cooking process by providing a sensor fixing part projecting inward for the handle of an inner pot and fixing an ultrasonic sensor facing under the inner pot. SOLUTION: The handle 7 is obtained by vertically matching a handle upper member 7a and a handle lower member 7b and forming a necessary free space 8 inside. The member 7a is extended inward beyond the upper surface of the collar 9 of the inner pot 3, bent in an L-shape to form a sensor fixing part 13 to fix the ultrasonic sensor 15 inside of it. A secondary coil 17 to be electromagnetically combined with a primary coil 16 on the side of a rice cooker main body is fixed to the space 8 to induce the mains-power on the side of the primary coil by a necessary voltage ratio. In addition, the driving circuit 18 of the sensor 15 and a received data transmission circuit 19 transmitting received data from the sensor 15 to outside are provided. The output terminal of the circuit 19 is connected with the receiving circuit 24 inside of the rice cooker main body through a hole 23 provided at the member 7b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level detecting device for a rice cooker.

[0002]

2. Description of the Related Art In a rice cooker such as a rice cooker, an ultrasonic sensor has been used to detect the amount of water required for rice cooking, and a method of converting the time required for ultrasonic waves to be reflected on the water surface and returned to a water level has been conventionally used. Known (see, for example,
4622).

In the above-mentioned publication, a sensor arm is attached to a shoulder portion of a rice cooker body so as to be rotatable in a horizontal direction, and an ultrasonic sensor is attached to a tip of the sensor arm to detect a water level. The sensor arm is rotated so that its tip faces the upper part of the inner pot. Also,
As another example, the sensor arm is mounted on the lower surface of the lid peripheral part of the rice cooker body so that it can be raised and lowered, and when detecting the water level, the lid is opened and raised, and the sensor arm is protruded horizontally and its tip is placed on the upper part of the inner pot. I'm facing.

[0004]

In the conventional water level detecting device as described above, each time the water level is detected, the user must manually operate the sensor arm so as to take a predetermined posture. However, there is a problem that a detection error easily occurs because the position and the posture of the sensor arm are not constant.

Therefore, an object of the present invention is to provide a water level detecting device which does not require any operation by a user, automatically detects a water level during a normal rice cooking process, and has high detection accuracy. And

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a rice cooker in which an inner pot is detachably housed in a rice cooker body, and a lid for covering the inner pot is attached to the rice cooker body. In the water level detection device of the vessel, a handle attached to the inner pot is provided with a sensor attachment part protruding inward of the inner pot, and a transmission / reception combined type ultrasonic sensor is attached to the sensor attachment part downward of the inner pot. As a power supply for driving the ultrasonic sensor, a battery is built in the handle, or a secondary coil is electromagnetically coupled to a primary coil of the rice cooker main body, and receives data from the ultrasonic sensor. A reception data transmission circuit for transmitting the signal to the rice cooker main body is built in the handle.

The handle has a handle upper member and a handle lower member which sandwich the collar of the upper edge of the inner hook from above and below, and projects the upper handle member inwardly of the inner hook over the above collar. Can be adopted.

A mounting hole penetrating inward and outward is provided below the brim of the upper edge of the inner hook, and a sensor mounting portion provided on the inner side of the handle passes through the mounting hole and protrudes inward of the inner hook. The configuration, wherein the angle of the ultrasonic wave transmitted from the ultrasonic sensor with respect to the water surface is 75 degrees or more, a receiving circuit opposed to the received data transmitting circuit is provided in the rice cooker main body, and a signal between both circuits is provided. A configuration in which transmission is performed by an optical signal can be employed.

In the water level detecting device having the above structure, when the inner pot is housed in the rice cooker body and the ultrasonic sensor is driven at the time of cooking rice, the ultrasonic sensor of the sensor mounting portion protruding inward of the inner pot is used to detect the inner pot. Ultrasonic waves are emitted toward the bottom.

The water in the inner pot may be filled before being stored in the rice cooker main body, but after storing, the water may be poured while transmitting ultrasonic waves. In each case, the ultrasonic wave reflected from the water surface is received, the received data is transmitted to the rice cooker main body via the reception data transmission circuit, and the water level is displayed on the rice cooker main body side.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The rice cooker according to the first embodiment shown in FIGS. 1 to 3 includes a rice cooker main body 1 and a lid 2 attached thereto.
And an inner pot 3 which is detachably housed in the rice cooker main body 1. The rice cooker main body 1 is provided with a water level detection button 4, a rice cook start button 5, various operation buttons, and a display unit 6 such as a liquid crystal display.

A pair of handles 7 made of synthetic resin are mounted on both left and right sides of the inner pot 3. As shown in FIG. 3 (a), the handle 7 is formed such that a handle upper member 7a and a handle lower member 7b are vertically aligned so that a required space 8 is provided therein. The lower handle 7b is provided with a mounting portion 11 along the lower surface of the collar 9 of the inner hook 3, and fixes the mounting portion 11 to the collar 9 with screws 12 inserted from the upper surface of the collar 9. The handle upper member 7a extends inward of the inner hook 3 beyond the upper surface of the collar 9, bends into an L shape inside the inner hook 3, and applies the bent end to the inner surface of the inner hook 3, thereby detecting the sensor. An attachment portion 13 is formed.

The upper handle 7a and the lower handle 7b are integrated at the upper and lower mating surfaces by bonding or forced fitting. When the handle 7 is attached as described above, the inner pot 3
The upper surface of the collar 9 and the upper surface of the handle upper member 7a are shown in FIG.
Since a step a shown in (b) occurs, in order to eliminate the step a, an upper edge member 14 made of a synthetic resin having the same thickness and a U-shaped cross section is attached to the collar 9 between the two handles 7. (See FIG. 1).

An ultrasonic sensor 15 is mounted inside the sensor mounting section 13. The ultrasonic sensor 15 is attached downward with a predetermined inclination angle such that the angle θ (see FIG. 2) of the ultrasonic wave transmitted from the ultrasonic sensor 15 with respect to the water surface becomes an angle of 75 degrees or more. If this angle is less than 75 degrees, the detection accuracy will decrease.

A secondary coil 17 that is electromagnetically coupled to the primary coil 16 of the rice cooker main body 1 is mounted in a space 8 inside the handle 7, and a commercial power supply of the primary coil 16 is connected to the secondary coil 17. The side is induced at a required voltage ratio. Further, in the space 8, a drive circuit 18 for the ultrasonic sensor 15 and a reception data transmission circuit 19 for transmitting reception data from the ultrasonic sensor 15 to the outside are provided.
These circuits 18 and 19 are connected to the output side of the secondary coil 17 so that power can be obtained. The two lead wires 21 and 22 of the ultrasonic sensor 15 are connected to a drive circuit 18 and a reception data transmission circuit 19, respectively.

The output end of the reception data transmission circuit 19 faces a hole 23 provided in the lower handle 7b, and a reception circuit 24 is provided inside the rice cooker main body 1 below the hole 23. Can be Signal transmission between the two is performed by optical transmission using infrared rays or the like.

The reception data transmission circuit 19 converts a time from transmission of an ultrasonic wave to reception of a reflected wave into a distance based on a signal input from the ultrasonic sensor 15, and converts the conversion result into a digital signal. It includes a conversion means for performing conversion, further performing electro-optical conversion, and transmitting as an optical signal.

The signal received by the receiving circuit 24 is
It is processed by the microcomputer in the rice cooker main body 1 and is displayed on the display unit 6 as a numerical value representing the water level.

The first embodiment is as described above.
When using this rice cooker, white rice ground with water is put into the inner pot 3 together with a small amount of water, the inner pot 3 is stored in the rice cooker main body 1, and the water level detection button 4 is operated. When the handle 7 of the inner pot 3 is fitted into the fitting portion 25 formed on the shoulder of the rice cooker main body 1, power is supplied to the drive circuit 18 and the reception data transmission circuit 19 by electromagnetic coupling between the primary coil 16 and the secondary coil 17. The ultrasonic waves are supplied and transmitted from the ultrasonic sensor 15 toward the inner pot 3. The user supplies water until the water level displayed on the display unit 6 rises to a value required for the amount of white rice at that time and the cooked state, and stops the water supply when the predetermined water level is reached.

Thereafter, the user closes the lid 2 and starts the rice cooking start button 5
To enter the rice cooking process. The packing 26 of the lid 2 is shown in FIG.
As shown in (1), the upper surface of the handle 7 and the upper surface of the upper edge member 14 flush with the upper surface are brought into contact with each other to achieve sealing.

Next, in the second embodiment shown in FIGS. 4 (a) and 4 (b), a sensor mounting portion 13 is provided on the inner surface of the handle 7 so as to protrude inward and is provided below the collar 9 of the inner hook 3. The sensor mounting portion 13 is provided in a mounting hole 27 penetrating inside and outside.
Is inserted. The ultrasonic sensor 15 is mounted in the same manner as described above inside the sensor mounting portion 13 protruding into the inner pot 3.

An engaging groove 28 is provided on the upper surface of the handle upper member 7a constituting the handle 7 and the engaging groove 28 is
The screw 29 screwed from the lower surface of the handle upper member 7a is pressed against the lower surface of the collar 9 and the engagement groove 28 is engaged with the upper surface of the collar 9 by the reaction force to fix the screw. ing. The packing 26 of the lid 2 is in contact with the upper surface of the collar 9 exposed from the engagement groove 28.

The other constructions and operations are the same as those of the first embodiment.

In each of the above embodiments, the voltage induced on the secondary coil 17 side by the electromagnetic coupling between the primary coil 16 and the secondary coil 17 is used as the power source for the drive circuit 18 and the like. These power supplies may be used.

[0025]

As described above, according to the present invention, the ultrasonic sensor is attached to the sensor attachment portion provided on the handle of the inner pot so as to protrude inward of the inner pot. There is the convenience that it is possible to know the water level without increasing the normal rice cooking procedure just by storing it in the rice cooker main body. In addition, since the position of the ultrasonic sensor and the position with respect to the inner pot are not changed, the water level can be detected with high accuracy.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a first embodiment.

FIG. 2 is a partially omitted sectional view of the above.

3A is an enlarged sectional view taken along line XX of FIG. 1; FIG. 3B is an enlarged sectional view taken along line YY of FIG. 1;

FIG. 4A is a partial cross-sectional view of the second embodiment, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rice cooker main body 2 Lid 3 Inner pot 4 Water level detection button 5 Rice cooking start button 6 Display part 7 Handle 7a Upper handle member 7b Lower handle member 8 Empty space 9 Collar 11 Mounting portion 12 Screw 13 Sensor mounting portion 14 Upper edge member 15 Ultra Sound wave sensor 16 Primary coil 17 Secondary coil 18 Drive circuit 19 Received data transmission circuit 21, 22 Lead wire 23 Hole 24 Receiving circuit 25 Fitting part 26 Packing 27 Mounting hole 28 Engagement groove 29 Screw

Claims (5)

[Claims] 1. An inner pot is detachably stored in a rice cooker body,
In a rice cooker water level detecting device in which a lid covering the inner pot is attached to the rice cooker main body, a handle attached to the inner pot is provided with a sensor attaching portion protruding inward of the inner pot, and the sensor attaching portion is provided on the sensor attaching portion. A transmission / reception type ultrasonic sensor is attached to the lower part of the inner pot, and as a power source for driving the ultrasonic sensor, a battery is built in the handle or electromagnetically coupled to a primary coil of the rice cooker main body. A water level detection device for a rice cooker, wherein a built-in secondary coil and a reception data transmission circuit for transmitting reception data from the ultrasonic sensor to the rice cooker main body side are incorporated in the handle. 2. The handle has a handle upper member and a handle lower member which sandwich the collar of the upper edge of the inner hook from above and below, and projects the upper handle member inward of the inner hook over the collar. 2. The sensor mounting part according to claim 1, wherein
The water level detection device for a rice cooker according to claim 1. 3. A mounting hole penetrating inward and outward below the flange of the upper edge of the inner pot, and a sensor mounting portion provided on an inner portion of the handle is passed through the mounting hole to protrude inward of the inner pot. The water level detecting device for a rice cooker according to claim 1, wherein: 4. The water level detecting device for a rice cooker according to claim 1, wherein an angle of the ultrasonic wave transmitted from the ultrasonic sensor to a water surface is 75 degrees or more. 5. The rice cooker main body is provided with a receiving circuit facing the received data transmitting circuit, and a signal between the two circuits is transmitted by an optical signal. Rice cooker water level detection device.