JPH0998884A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically feed a quantity of water corresponding to the rice quantity in a pot. SOLUTION: The weight of a pot 5 is detected by a weight sensor 10, the weight of the rice in the pot 5 is obtained from the detected weight, and the water quantity suitable for the rice quantity is set. The solenoid valve 21 of a water feed tank 20 is opened, and the water in the water feed tank 20 is fed into the pot 5. When the weight sensor 10 detects the weight added with the water quantity to be fed to the first detected weight, the solenoid valve 21 is closed to stop the water feed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker capable of automatically supplying an amount of water according to the amount of rice contained in a pot.

[0002]

[Problems to be Solved by the Invention] In a rice cooker for business use,
It is convenient because it automatically performs washing from rice to cooking rice.
It is large and non-portable, and of course cannot be used for domestic purposes. On the other hand, a tabletop rice cooker used at home is small and convenient to carry, but the work of storing rice and the amount of water in the pot according to the amount of rice must be done manually, especially the amount of rice. If you put the right amount of water in the pan and make a wrong measurement, you will not be able to cook delicious rice.

The present invention has been made in view of the above circumstances, and its purpose is to be convenient to carry and to automatically supply an appropriate amount of water according to the amount of rice contained in a pan without excess or deficiency. To provide a rice cooker.

[0004]

To achieve the above object, the present invention comprises a main body having an upper lid, a pan provided in the main body, and heating means for heating the pan. In the rice cooker, a weight sensor for detecting the weight of the pot is provided, and a water tank is provided on the lid, and the weight sensor detects the weight of the pot containing the washed rice, and the detected weight is It is characterized in that a suitable amount of water is supplied from the water supply tank into the pot.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will now be described with reference to FIGS.
A description will be given based on FIG. In FIG. 1 showing the overall structure of a tabletop rice cooker for home use, an inner container 2 is arranged in a main body 1, and a lid 3 for opening and closing the inner container 2 is provided with a spindle 4.
It is provided so as to be openable and closable. The pot 5 is detachably stored in the inner container 2. This pot 5
The lid plate 6 for opening and closing the upper opening is detachably attached to the protrusion 3a at the center of the lower surface of the lid 3, and the upper opening of the pan 5 is opened and closed as the lid 6 is opened and closed.

A pedestal 7 that supports the bottom surface of the inner container 2 is provided in the main body 1. A heating coil 8 as a heating means is mounted on the pedestal 7, and the heating coil 8 is supplied with a high frequency current by an inverter device 9 to heat the pot 5 by induction heating (actually, the pot 5 is Fever).

A weight sensor 10 for detecting the weight of the pan 5 is provided on the inner bottom of the inner container 2. The weight sensor 10 includes an inner container 2 as shown in FIG.
A flat plate-shaped sensor base 12 supported movably up and down via a shaft 11, a compression coil spring 13 provided between the inner container 2 and the sensor base 12 for urging the sensor base 12 upward, and a shaft 11 And a detection coil 15 arranged in the inner container 2.

In the weight sensor 10 having such a configuration, when the pan 5 is housed in the inner container 2, the sensor base 12 receives the weight of the pan 5, and the compression coil spring 13 is provided in an amount corresponding to the weight of the pan 5.
Since it moves down while compressing, the distance between the ferrite 14 and the detection coil 15 changes, and the output voltage of the detection coil 15 changes. Since the output voltage of the detection coil 15 at this time has a value according to the distance between the ferrite 14 and the detection coil 15, the weight of the pan 5 can be detected by the output voltage. Further, on the back surface of the sensor base 12, a rice cooking control temperature sensor 16 for detecting the bottom temperature of the pan 5 via the sensor base 12 is provided.

On the other hand, a tank chamber 17 is formed in the lid 3, and an opening on the upper surface of the tank chamber 17 is formed on the lid 3 by a shaft 1.
A cover 19 rotatably and rotatably supported by 8 is opened and closed. Further, in the tank chamber 17, a water supply tank 20 that stores the water for cooking rice to be supplied into the pan 5 is detachably stored. This water tank 20
Is formed of, for example, transparent plastic, and the water supply port 2
0a, a vent hole 20b, and a water injection port (not shown) for injecting water, and the water injection port is closed by a removable cap. Further, the water supply port 20a is provided with an electromagnetic valve 21 as an opening / closing device for opening and closing the water supply port 20a. The ventilation holes 20b are provided for injecting air into and out of the water supply tank 20 as water is injected into the water supply tank 20 and water is supplied from the water supply tank 20 to the pan 5 described later.

As described above, the water supply tank 20 includes the cover 1
Since the water tank 20 is detachably arranged in the tank room 17 which is opened and closed by 9, if the water tank 20 is removed from the tank room 17 and taken to the place where the water tap of the kitchen is installed, Well, you don't have to carry the entire rice cooker.

Here, the water supply tank 20 has a tank chamber 17
When the lid 3 is opened, it is installed so that the vent hole 20a is located on the side opposite to the support shaft 4 of the lid 3, so that when the lid 3 is opened, the water in the water supply tank 20 flows from the vent hole 20b. It is made so as not to leak out. A hole 6a is formed in the cover plate 6 so that the water supply port 20a of the water supply tank 20 arranged in the tank chamber 17 faces the pot 5 through the hole 6a. Therefore, when the electromagnetic valve 21 opens the water supply port 20a, the water in the water supply tank 20 is supplied into the pan 5. At this time, since the water supply tank 20 is provided in the lid 3 existing above the pan 5, the water is supplied into the pan 5 by a drop, so that the water supply pump is not required and the structure is simple. Becomes

On the lower surface side of the lid 3, a heater 22 for heat retention is provided.
The heat-retaining heater 22 is also used as a heater for heating the water for cooking rice in the water supply tank 20. A temperature sensor 23 for keeping warm is arranged on the lower surface of the lid 3 to detect the temperature in the vicinity of the heater 22 for keeping warm. A water temperature control temperature sensor 24 for detecting the water temperature is arranged. An ultraviolet lamp 25 is attached to the lower surface of the cover 19 as a sterilizing device. The ultraviolet lamp 25 is always on and irradiates the water in the water supply tank 20 with ultraviolet rays to sterilize it.

On the other hand, the operation portion 2 is provided on the front surface of the main body 1.
6 is provided, and various key switches (not shown) are arranged on the operation unit 26. Further, on the back side of the operation unit 26, a control device 27 mainly composed of a microcomputer is arranged, and this control device 27 includes
Signals from the various key switches, the weight sensor 10, and the temperature sensors 16, 23, 24 are input. Then, the control device 27 controls the inverter device 9, the solenoid valve 21, the heat retention heater 22 and the like based on these input signals and a preset program.

The solenoid valve 21 on the side of the water supply tank 20, the temperature sensor 24 for controlling the water temperature, and the controller 27 on the side of the main body 1 are connected via a detachable connection terminal (not shown).
When taking out the water supply tank 20 from the tank chamber 17, the connection terminal is pulled out.

In order to explain the control contents of the control device 27, first, the control of the rice cooking operation will be described. The rice cooking operation is started when the key switch for starting rice cooking is operated. This rice-cooking operation is usually performed with a pan 5 as shown in FIG.
Put the rice in water in water, heat the water to a predetermined temperature and maintain it for a predetermined time, "Hitashi" process, "boil rice" process to heat water to boil rice, cooked rice at high temperature It consists of a "Murashi" process in which the rice is maintained for a predetermined time as it is, and is configured to automatically start the heat retention operation after the rice cooking operation is completed.

In each step of the above rice cooking operation, the control device 27 controls the heating of the pan 5 by the heating coil 8 via the inverter device 9 based on the output signal from the rice cooking control temperature sensor 16. To be executed. That is,
The control device 27 executes the “hot” stroke by continuing the state in which the temperature sensor 16 detects the predetermined hot water temperature for a predetermined time, and then switches the heating coil 8 from the low output state until then to the strong output state. The "cooking" process is performed by setting the heating coil 8 to a strong output until the temperature detected by the temperature sensor 16 rises sharply from a constant state (water boiling state) (so-called dry-up of water in the pot 5). Then, the “muramura” process is performed by continuing the state in which the temperature sensor 16 controls the heating coil 8 so as to maintain a predetermined high temperature for a certain period of time.

After the end of the "Murashi" stroke, the control device 27 stops the output of the heating coil 8 and maintains the temperature detected by the temperature control sensor 23 for a predetermined temperature (about 70 ° C.). The warming operation is executed by controlling the warming heater 22 as described above. During this heat retention, the control device 27 intermittently supplies a small amount of water to the pot 5 by energizing the solenoid valve 21 for a short time every 30 minutes, for example, after 1 hour has elapsed since the heat retention operation was started. By intermittently supplying a small amount of water into the pan 5, the rice is prevented from drying due to heating during heat retention.

When the reheating key switch is operated during the heat retention, the control device 27 energizes the solenoid valve 21 for a short time to supply a small amount of water into the pot 5 and the heat retention sensor 23. The heat-retaining heater 22 is set to a strong output state so as to be in a state of detecting a predetermined high temperature. Here, the term "reheating" means that the heat-retaining temperature is too low as a temperature at which the rice is deliciously eaten, so that the rice is heated to the same temperature as when the rice is cooked. Then, the drying of the rice by the reheating is prevented by the water supplied in a small amount.

Now, when the fully automatic rice cooking key switch is operated, the controller 27 is configured to supply the pot 5 with water in an amount corresponding to the amount of rice contained in the pot 5. There is. When this fully automatic rice cooking is performed, washed rice is commercially available. Therefore, it is preferable to use the commercially available washed rice (hereinafter, simply washed rice).

That is, a desired amount of washed rice is put in the pan 5 and placed in the inner container 2, and the lid 3 is closed. At this time, water is stored in the water supply tank 20, and the water is suitable for hot rice by controlling the heater 22 for keeping warm based on the temperature detected by the temperature sensor 24 for controlling water temperature. It is assumed that the temperature is maintained at the specified temperature (heating temperature of the hitoshi stroke).

When the lid 3 is closed, the control device 27 causes the weight sensor 10 to detect the weight of the pan 5. In this case, pan 5
Since the weight of the single body is previously stored as data in a memory (not shown), the control device 27 subtracts the weight of the single pot 5 from the weight detected by the weight sensor 10 to detect the weight of only washed rice.

In a memory (not shown), the weight of washed rice and the amount (weight) corresponding to the amount of washed rice are stored as a table, and the controller 27 obtains the amount of water corresponding to the weight of washed rice from the memory. , Add to the washed rice weight. After that, the control device 27 energizes the solenoid valve 21 to open it. Then, the water in the water supply tank 20 is supplied into the pan 5, and the weight detected by the weight sensor 10 increases as the water supply progresses, so that the detected weight is equal to the sum of the washed rice weight and the water amount. When this happens, the solenoid valve 21 is turned off and water supply is stopped. As described above, the amount of water corresponding to the amount of washed rice stored in the pot 5 is supplied to the pot 5 in just enough amount. After this water supply, the control device 27 shifts to the control of the rice cooking operation.

Then, when shifting to the rice cooking operation, first, the "hot water" process is executed, but the water supplied from the water supply tank 20 into the pan 5 is preheated to the hot water temperature,
Since the water temperature is constant regardless of changes in temperature,
In some cases, there is no risk of changing the soaking temperature or soaking time. Therefore, the water absorption rate of rice in the "Hitashi" process becomes almost constant, and delicious rice can be cooked at all times.

On the other hand, the control device 27 has a calendar function and a rice cooking reservation function. The rice cooking reservation function is a function that, when the rice cooking end time is set by operating the reservation key switch, the rice cooking operation is executed so that the rice cooking is completed at that time.

When this rice cooking reservation is made, the controller 27
Is configured to perform the water supply operation into the pot 5 described above at a time point before the time when the rice is cooked (for example, one hour) before the rice is cooked. Therefore, in the reserved rice cooking, unlike the case where the pot 5 is housed in the inner container 2 and the water supply operation is performed at the same time, the water absorption rate becomes too large due to the rice being soaked in water for a long time. There is no fear.

If it is desired to complete the cooking of rice as soon as possible after the pan 5 is stored in the inner container 2, the key switch for cooking rice is operated for a short time. Then, the control device 27
After determining the amount of water according to the weight of washed rice in the pan 5, the minimum necessary amount of water that can wash the rice in the pot 5 is determined from the weight of washed rice, and the amount of water is supplied from the water supply tank 20. Then, during the "Hitashi" stroke, the output of the heat retention heater 22 is increased to bring the water in the water supply tank 20 to a high temperature, and at the end of the "Hitashi" stroke, the remaining amount of water is supplied into the pan 5. As described above, since the water heated to the high temperature in the water supply tank 20 is supplied into the pot 5 during the "Hitashi" stroke, the temperature of the water in the subsequent "cooking" stroke rises faster, and as a result, It can cook rice in a short time.

By supplying the necessary amount of water to the pan 5 separately in two times as described above, even if the water in the water supply tank 20 is not preheated to the hot water temperature, the hot water temperature is increased. Because the amount of water that needs to be heated up is small,
The time required for the "Hitashi" process is shortened and rice can be cooked for a short time.

To cook rice more rapidly, the key switch for rapid rice cooking is operated. Then, the control device 27
Sets the heater 22 for heat retention to a high output state, and
The water in 0 is heated to high temperature. Meanwhile, the washed rice is put in the pan 5 and stored in the inner container 2. As a result, the high-temperature water in the water supply tank 20 is supplied into the pot 5, so that the control device 27 thereafter omits the "hot water" process and immediately executes the "cooking" process. Therefore, rapid rice cooking is possible.

By the way, the hardness of the cooked rice is usually, softened, firmed, etc., depending on the user. In addition, there are various types of rice washing, such as domestic rice, Japonica rice (US rice, Australian rice), Indica rice (Thailand rice), etc. To cook delicious rice, the amount of water can be changed depending on the type of rice. preferable.

In this embodiment, the hardness of the cooked rice can be set to three levels of normal, soft and firm by the key switch, and the type of rice to be cooked can be set. There is. Then, the control device 27 is configured to correct the water supply amount according to the hardness of the selected rice and the type of rice.

Here, the relationship between the capacity of rice and the capacity of water relating to the hardness of rice and the relationship between the capacity of rice and the capacity of water relating to the type of rice are shown in FIGS. 4 and 5. In addition, rice 1
The cup is usually 150 g and one cup of water is 200 g.

Since the relation between the weight of rice and the amount of water (weight) stored in the memory is the case of cooking rice of ordinary hardness with domestic rice, it is used as a correction for the set hardness of rice. Is the same as the normal amount of water that is set according to the weight of rice when set to normal, and assuming that the amount of water in this case is 1, the amount of water is 1.2 times the amount of normal soft water , If it is hard, correct it to 0.8 times the amount of water. Also, when the type of rice used is domestic rice, it is the same as the amount of water set according to the weight of the rice. 1.2 times more water than rice,
When set to Indica rice, correct the amount of water to 1.5 times.

When the hardness of rice and the type of rice are set in this way, the amount of water is corrected accordingly, so that the rice of desired hardness can be automatically cooked and the rice can be cooked according to the type of rice. It can supply the optimum amount of water and can cook delicious rice in any case.

FIG. 6 shows another embodiment of the present invention.
The same parts as those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. That is, in this embodiment, the water supply tank 2
0 is fixed in the lid 3, and the cover 1 of the above-mentioned embodiment is
The portion corresponding to 9 is also integrated with the lid 3. And
A water injection pipe 20c is projectingly provided on a portion of the upper portion of the water supply tank 20 on the support shaft 4 side of the lid 3, and the water injection pipe 20c is attached to and detached from a hose 28 connected to a tap (not shown) of the water supply. It is adapted to be connected via a joint 29. Also,
A pair of joint members 29a, 29 constituting the removable pipe joint 29
A water purifier 30 accommodating activated carbon, a hollow fiber membrane or the like is provided on the joint member 29b on the hose 28 side of b.

In this embodiment having such a structure, tap water can be supplied into the water supply tank 20 by the hose 28, so that it is not necessary to take the water supply tank 20 out of the lid 3 and carry it to the sink with a tap. Water tank 2
Water supply to 0 can be performed easily. Further, since the tap water is purified by the water purifier 30, it is possible to cook delicious rice with the purified water from which the red rust and the chlorine odor contained in the tap water have been removed.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following expansions and modifications are possible. The heating means for heating the pan 5 may be a heater. The weight sensor is composed of a pair of electrode plates whose facing distance is changed according to the weight of the pan 5, and is configured to detect the weight based on a change in capacitance between the electrode plates and a device using other strain gauges. You may.

The rice is not limited to commercially available rice, but rice washed by the user may be used. To measure the amount of water supplied to the pan 5, for example, a water absorption tank 20 is provided with a measuring chamber, and the measuring chamber is configured to be filled with water once to supply water. You may make it measure the amount of water supply to 5.

[0038]

As described above, according to the present invention, the following effects can be obtained. According to the first aspect of the invention, it is convenient to carry and the amount of water according to the amount of rice stored in the pan can be automatically supplied. Further, since the lid is provided with a water supply tank for supplying water to the pot, water can be supplied by a drop, which simplifies the water supply configuration from the water supply tank to the pot.

According to the second aspect of the invention, since the rice is soaked in water heated to a constant temperature, it is possible to make the water absorption rate of the rice constant during dipping. According to the invention of claim 3,
Initially, a small amount of water is supplied to the pot for hot water, so
The water can be heated to a temperature suitable for hot water in a short time and can contribute to cooking rice for a short time. In the invention described in claim 4, the water remaining in the water supply tank can be sterilized. Claim 5
In the invention described, only the water supply tank can be carried to the faucet of the tap water for water injection. According to the invention of claim 6, it is possible to cook rice of desired hardness. According to the invention of claim 7, it is possible to supply water in an amount corresponding to the type of rice.

In the eighth aspect of the invention, the rice does not absorb a large amount of water before the rice cooking is started. In the invention according to claim 9, it is possible to prevent the rice from drying during the heat retention.
According to the tenth aspect of the invention, when the rice that has been kept warm is reheated, it can be prevented from drying.

[Brief description of drawings]

FIG. 1 is a longitudinal side view showing one embodiment of the present invention.

FIG. 2 is a sectional view of the weight sensor.

[Figure 3] Graph showing changes in pot temperature during rice cooking operation

FIG. 4 is a diagram showing the relationship between the amount of rice and the amount of water relating to the hardness of cooked rice.

FIG. 5 is a diagram showing the relationship between the amount of rice and the amount of water relating to rice types.

FIG. 6 is a diagram corresponding to FIG. 1, showing another embodiment of the present invention.

[Explanation of symbols]

In the figure, 1 is a main body, 3 is a lid, 5 is a pan, 8 is a heating coil (heating means), 10 is a weight sensor, 20 is a water tank, 21
Is an electromagnetic valve, 22 is a heater for heat retention, and 25 is an ultraviolet lamp (sterilizer).

Claims (10)

[Claims] 1. A rice cooker comprising a main body having an upper lid, a pan provided in the main body, and heating means for heating the pan, wherein a weight sensor for detecting the weight of the pan is provided. Along with this, a water supply tank is provided on the lid, the weight sensor detects the weight of the pot containing the washed rice, and the amount of water corresponding to the detected weight is supplied from the water supply tank into the pot. Rice cooker with a structure. 2. The rice cooker according to claim 1, wherein a heater for heating water in the water supply tank is provided, and the water heated to the hot water temperature of rice is supplied into the pan by the heater. 3. The water supply from the water supply tank into the pot is performed by initially supplying an amount of water that can soak the rice in the pot with water, and supplying the remaining amount of water after completion of dipping. The rice cooker according to claim 1. 4. The rice cooker according to claim 1, further comprising a sterilizer for sterilizing water in the water supply tank. 5. The rice cooker according to claim 1, wherein the water supply tank is removable. 6. The rice cooker according to claim 1, wherein the amount of water supplied to the pan is corrected according to the set hardness of the rice after cooking. 7. The rice cooker according to claim 1, wherein the amount of water supplied to the pot is configured to be corrected according to the set type of rice. 8. The rice cooker according to claim 1, further comprising a reservation function when the rice is cooked, and the water supply to the pot is performed before the time when the reserved rice is cooked by the time required to cook the rice. vessel. 9. The rice cooker according to claim 1, wherein a small amount of water is intermittently supplied during the heat retention after the rice is cooked. 10. The rice cooker according to claim 1, wherein a small amount of water is supplied when heating to a temperature higher than the heat retention temperature during heat retention.