JP3106666B2 - rice cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker provided with a water supply device for automatically supplying water to a pot containing rice.

[0002]

2. Description of the Related Art As a conventional rice cooker of this type, for example, one having a structure disclosed in Japanese Patent Application Laid-Open No. 2-215413 is known.

That is, as shown in FIG. 8, a pot 1 for storing rice and a rice cooker body provided with a heater 2 for heating the pot 1 are arranged at an upper part of a cabinet, and a rice bin 3 is placed at a lower part of the cabinet. I have arranged. A rice weighing device 4 is arranged at the rice delivery outlet of the rice bin 3, and a predetermined amount of rice is sent out to the rice polishing machine 5 by the rice weighing device 4. The rice polished by the rice polisher 5 reaches the rice cooker main body arranged at the upper part of the cabinet via the transfer pipe 6, and the rice is sent into the pot 1 of the rice cooker main body.

[0004] Tap water is supplied through a water supply valve 12 to a water tank 7 provided side by side with the rice cooker main body. In addition, water tank 7
The water stored in the pan 1 is supplied into the pan 1 from a water supply nozzle 10 above the pan 1 by a pump 8. Reference numeral 11 denotes control means for controlling operations of the heater 2, the rice metering device 4, the rice polishing machine 5, the pump 8, and the water supply valve 12.

[0005] The control means 11 first measures the amount of rice set by the user with the rice measuring device 4, for example, 4 rice, and sends it to the rice polishing machine 5. The rice polishing machine 5 removes bran on the surface of rice in the same manner as for washing rice. The rice from which the rice bran has been removed by the rice polishing machine 5 is sent into the pot 1 via the transfer pipe 6. Next, the water supply valve 12 is opened to store water in the water tank 7.
The time point when the water supply valve 12 is closed is the time point when the amount of water according to the amount of rice in the pot 1 is stored in the water tank 7. The water stored in the water tank 7 is supplied to the pot 1 by operating the pump 8, and after the water is supplied, the power supply to the heater 2 is started to perform the pre-cooking and the rice cooking process.

[0006]

However, in the above-mentioned conventional structure, tap water is simply stored in the water tank 7 and the cold water is supplied into the pot 1, so that the pre-cooking process executed after the water supply is performed. There was a problem that the time required was long. That is, in the pre-cooking step, the temperature in the pot 1 is maintained at the pre-cooking temperature (about 45 to 65 ° C.) in order to promote water absorption of rice. Once supplied, it took time for the temperature in the pot 1 to reach the pre-cooking temperature, and the pre-cooking time was lengthened.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to reduce the time of the pre-cooking step, shorten the time from pre-cooking to the end of rice cooking, and execute the pre-cooking step at an optimum pre-cooking temperature.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a pot heating means for heating a pot, a rice quantity detecting means for detecting the quantity of rice in the pot, and a water tank for storing water. And a water supply device for supplying water from the water tank to the pan, a water supply heating means for heating water supplied from the water supply device to the pan, and control contents of water supply, pre-cooking, and rice cooking processes. The process storage means, and a control means for controlling the pot heating means, the water supply device, the feed water heating means according to the control content of the process storage means, the control means,
The water supply device before the start of the pre-cooked step operates the feedwater heater means supplies hot water to the pan, the hot water
Temperature in the pot from the pre-cooking temperature when rice and rice are mixed
Is in order to prevent the greatly reduced, high feed water temperature of the hot water the water supplied into the pot when the detection rice of the rice quantity detecting means is larger
That's a comb .

[0009]

According to the above construction, the temperature of the water supplied to the pot is raised by the feed water heating means to form hot water, and the temperature in the pot is increased by the hot water. in, with less time for raising the temperature to a temperature cooked before the temperature in the pot, by when there are rice large amount in the pot to supply hot water with increased water temperature, in pot Even if the amount of rice is large and the temperature of the supplied hot water is large, the temperature in the pot after the hot water is supplied does not fall significantly below the pre-cooking temperature.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

First, the overall configuration of the rice cooker according to the present embodiment is shown in FIG.
This will be described below. In the figure, reference numeral 13 denotes a rice cooker main body, in which a pot storage portion 15 for storing a pot 14 is provided. The pot housing 15 has a lower portion formed by a protective frame 16 made of a nonmagnetic material, for example, a heat-resistant synthetic resin, and an upper portion formed by a cylindrical side member 17 made of a metal plate. An openable and closable lid 18 is disposed on the upper portion of the pot 14, and the inner lid 20 is heated by a lid heater 19 disposed inside the lid 18. Further, a donut-shaped first heating coil 21 is arranged outside the protection frame 16 so that the bottom of the pot 14 is induction-heated,
A side heater 22 is attached to the side member 17 to heat the side of the pan 14.

A removable water tank 26 is provided in front of the rice cooker body 13, and an outlet 27 is provided below the water tank 26. The outlet 27 is connected to an inlet of a pump 28 driven by a motor 29. Pump 28
A water supply pipe 30 is connected to the outlet of the water supply pipe, and a switching valve 31 is disposed in the middle of the water supply pipe 30. The flow of water is switched to the ladle outlet 33 side channel facing the.
A water purifier 34 is attached to the inflow port 32 of the water tank 26 to purify water from the inflow port 32. A heating element 35 made of a magnetic material is disposed on the inner bottom of the water tank 26, and the heating element 35 is induction-heated by a second heating coil 36 disposed below the water tank 26.

The second heating coil 36 and the first heating coil 21 are supplied with a high-frequency current from the inverter circuit 25 to generate a high-frequency magnetic field. In particular, the magnetic flux from the first heating coil 21 leaks downward. To prevent
A ferrite rod 37 is disposed below the first heating coil 21. The pan temperature sensor 23 is located in the pan storage unit 15 through a through hole 24 provided in the protection frame 16,
To detect the temperature in the pot 14. Reference numeral 38 denotes a feed water temperature sensor 38 for detecting the temperature of feed water supplied from the water tank 26, which is attached to the water supply pipe 30 on the outlet side of the pump 28.

Next, the circuit configuration of the rice cooker will be described with reference to FIG. In the figure, a power switch 39 is connected between an AC power supply 40 and a full-wave rectifier 41. The waveform rectified by the full-wave rectifier 41 is the choke coil 4
2. It is supplied to the smoothing capacitor 43. The smoothing capacitor 43 smoothes the full-wave rectified waveform to make it DC, and supplies the DC to the inverter circuit 25. The choke coil suppresses the high-frequency current from the inverter circuit from leaking to the AC power supply. The inverter circuit 25 includes a resonance capacitor 44, a transistor 45 as a switching element, and a diode 46 connected in parallel with the transistor 45.

Resonant capacitor 44 of inverter circuit 25
In parallel with the first heating coil 21 and the second heating coil 36
And the first and second heating coils 21 and 36
Is switched by the first relay contact 47. The energization of the lid heater 19 and the side heater 22 is controlled by opening and closing the second relay contact 48. The first and second relay contacts 47 and 48 are connected to relay driving means 49.
Is driven to open and close. Motor 2 for driving pump 28
9 is driven by the motor driving means 50 and the switching valve 31
Is driven by the switching valve driving means 51.

The control means 52 is constituted by a microcomputer or the like, and inputs signals of various detection means.
The pan temperature detecting means 53 converts the value detected by the pan temperature sensor 23 into an electric signal, and outputs the detected temperature in the pan 14 as an electric signal. The feedwater temperature detecting means 54 is provided by the feedwater temperature sensor 3.
8 is converted into an electric signal, and the detected feedwater temperature is output as an electric signal.

The rice amount detecting means 55 detects the amount of rice in the pot 14, and an example thereof is shown in FIG. In the figure, 56
Is a moving member that comes into and out of the pot storage portion through the through-hole 24 of the protective frame 16, the pot temperature sensor 23 is arranged on the upper surface of the moving member 56, and is configured to be in contact with the bottom of the pot 14.
The moving member 56 is always moved upward by the spring 57, that is, the pan 1
4 is urged to the bottom side, and is always in contact with the bottom of the pan 14. The lower end portion 58 of the moving member 56 contacts the left side of the rotating member 60 that rotates about the shaft 59, and the protrusion 61 on the right end side of the rotating member 60 contacts the distortion measuring member 62.

The rice amount detecting means having the above structure receives the weight of the rice in the pot 14 and the pot 14 by the moving member 56, and the received force is distorted through the lower end 58, the rotating member 60, and the protrusion 61. It is added to the quantity measuring device 62. Therefore, as the amount of rice in the pot 14 increases, the distortion amount of the distortion measuring device 62 increases, and the distortion amount of the distortion measuring device 62 is measured.
The amount of rice in the pot 14 is detected.

The water supply amount detecting means 63, which is another detecting means, detects the amount of water supplied into the pot 14, and an example thereof is shown in FIG. In the figure, reference numeral 64 denotes a first electrode plate disposed on the inner bottom of the water tank 26, and the first electrode plate 64 is a heating element 35 which is induction-heated by a second heating coil 36.
You may also be used. In addition, a second electrode plate 65 extending in the up-down direction is also provided on the inner side surface of the water tank 26. The first electrode plate 64, the second electrode plate 65, and both electrode plates 6
A capacitor is formed by the water and air dielectric between 4,65. A second electrode plate 65 constituting a capacitor is connected to an inverting input terminal of a voltage comparator 66 having good saturation characteristics,
The voltage comparator 66 is connected with other resistors to form an astable multivibrator. A waveform shaping circuit 67 is connected to the output side of the astable multivibrator, and the waveform shaping circuit 67 shapes the output waveform of the astable multivibrator into a rectangular wave and outputs it to the counter 68. The counter 68 counts the rectangular waves from the waveform shaping circuit 67. The reset terminal R of the counter 68 has a clock pulse generator 69.
Is connected, and the count data is reset by a signal output from the clock pulse generating means 69 at regular intervals.

The operation of the water amount detecting means will be described. When the water in the water tank 26 is supplied into the pot 14 by the pump 28, the water level in the water tank 26 decreases. Therefore, the dielectric constant of the dielectric of the capacitor changes (the ratio of water to air changes), and the capacitance of the capacitor changes. Accordingly, the oscillation frequency of the astable multivibrator changes, and the count number counted by the counter 68 within a certain period of the clock pulse generating means 69 changes. Therefore, this counter 6
The water level in the water tank 26 can be detected based on the count number of 8, and the amount of water supplied to the pot 14 can be detected.

Returning to FIG. 1, the description will be continued. In addition to the various detection means described above, the control means 52 inputs the process storage means 70. The process storage means 70 stores the control contents of various processes such as rice amount detection, water supply, pre-cooking, and rice cooking.
The process storage means 70 is a process control means 71 in the control means 52.
Output to The process control means 71 is a pan heating control means 72,
The operation control of the water supply heating means 73 and the water supply amount heating means 74 is performed, and the control according to various control contents of the process storage means 70 is performed.

The pan heating means 72 controls the operation of the relay driving means 49 and the oscillation circuit 75. The oscillating circuit 75 controls a switch driving means 76 for driving the transistor 45 on and off, and sets a predetermined oscillating frequency (for example, 2
At 0 kHz), the transistor 45 is turned on and off, and a high-frequency current having a predetermined frequency is supplied to the inverter circuit 25. The relay driving means 49 switches the first contact 47 to the contact NC side, supplies the high frequency current of the inverter circuit 25 to the first heating coil 21, and heats the pan 14. Further, the pan heating control means 72 inputs the temperature detected by the pan temperature detecting means 53, controls the operation of the oscillation circuit 75 by the control command temperature from the process control means 71, and controls the heating operation of the first heating coil 21. I do.

The feed water heating control means 73 controls the operation of the motor control means 76 and the switching valve control means 77 in addition to the oscillation circuit 75 and the relay driving means 49. Motor control means 76
Controls the operation of the motor 29 via the motor driving means 50, and can operate and stop the pump 28. The switching valve control means 97 operates the switching valve 31 via the switching valve driving means 51 to switch the flow path. Further, the first relay driving means 49 is operated to change the first contact 47 to the contact NO.
Side, and the high-frequency current of the inverter circuit 25 is supplied to the second heating coil 36 to heat the water in the water tank 26. The feed water heating control means 73 is provided by the feed water temperature determining means 7.
8 and the feedwater temperature detecting means 54 are inputted. The feed water temperature determining means 54 determines the feed water temperature according to the rice quantity from the rice quantity detecting means 55, and uses the determined feed water temperature as the feed water heating control means 7.
3 and the feedwater heating control means 73 compares the detected temperature of the feedwater temperature detection means 54 with the determined feedwater temperature, and operates and stops the oscillation circuit 76.

The water supply amount control means 94 is provided with a water supply amount detection means 79.
And the water supply amount detecting means 68, and the motor control means 7
6 and the operation of the switching valve control means 77. The water supply amount determining means 79 determines the water supply amount according to the rice amount detected by the rice amount detection means 55 and outputs the water amount to the water supply amount control means 74. The water supply amount control means 74 compares the water supply amount detected by the water supply amount detection means 63 with the determined water supply amount, and the motor control means 76 controls the operation period of the motor 29. In addition, the water supply amount control means 74
In order to supply the water in the water tank 26 into the pan 14, the flow path of the switching valve 31 is switched by the switching valve control means 77 so that the water is supplied from the water tank 26 into the pan 14.

Next, the control contents of the control means will be described with reference to FIGS.
This will be described below. First, in step 80 of FIG.
The rice quantity m is input from the rice quantity detection means 55. When it is determined that the input rice quantity m is less than 2 (step 81), in step 82, the hot water supply temperature T1 to be supplied into the pot 14 is set to 52 ° C. Rice quantity m is 2 in step 81
If so, it is determined in step 83 whether or not the rice quantity m is between 2 and 4 inclusive. Rice quantity m is more than 2 go 4
If not, the feedwater temperature T1 is set to 54 ° C. in step 84. In the same manner as described above, in step 85, if the rice amount m is 4 or more and less than 6 sets, the water supply temperature T1 is set to 56 ° C. in step 86, and the rice amount m is 6 or more and less than 8 sets in step 87. In step 88, the water supply temperature T1 is set to 58 ° C., and if it is determined in step 87 that the rice quantity m is equal to or greater than 8, the water supply temperature T1 is set to 6 in step 89.
Set to 0 ° C.

As described above, the water supply temperature T1 of the hot water supplied into the pot 14 is set according to the rice amount m. Therefore, when the rice amount m is large and the heat absorbed by the rice is large, the pot 14 The temperature of the hot water to be supplied is raised to prevent the temperature in the pot 14 from dropping significantly below the pre-cooking temperature, for example, 50 ° C., in a state where the hot water and the rice are mixed.

Next, at step 90, a water supply amount Q of hot water supplied into the pot 14 is calculated. The water supply amount Q is determined by the rice amount m detected by the rice amount detection means 55. Specifically, the water supply amount Q is determined by an operation of Q = m * a + b (a and b are constants). . In step 91, the detected feed water temperature T of the feed water temperature detecting means 54 is input, and in step 92, the detected feed water temperature T is set to the feed water temperature T set by the rice quantity m.
It is determined whether or not 1 has been exceeded. If the detected water supply temperature T has not reached the set water supply temperature T1, the flow path of the switching valve 31 is switched to the water tank 26 side in step 93, the first contact 47 is switched to the NO side, and the motor 2
9 and the inverter circuit 25 are driven.

Then, the motor 29 drives the pump 28, and the water in the water tank 26 is sent again into the water tank 26 through the water outlet 27, the water supply pipe 30, the switching valve 31, and the inlet 32. Perform the operation. On the other hand, since the high-frequency current of the inverter circuit 25 is supplied to the second heating coil 36 via the first contact 47, the second heating coil 36 heats the heating element 35 at the bottom of the water tank 26,
The water temperature in the water tank 26 is raised. Since the water in the water tank 26 is circulating during the heating period by the heating element 35, the temperature distribution of the water in the water tank 26 becomes uniform, the temperature difference between the upper part and the lower part is reduced, and Can be supplied into the pan 14.

If it is determined in step 92 that the detected feedwater temperature T has exceeded the set feedwater temperature T1, step 93 shown in FIG. 6 is executed. In step 93, the flow path of the switching valve 31 is switched to the pot 14 side, and the inverter circuit 25
And the motor 29 is turned off. At step 94, a predetermined time,
For example, a delay time of 3 seconds is provided to wait for the water surface in the water tank 26 to stabilize. With this delay time, the water tank 26
Since the inside water surface is stabilized, the amount of water in the water tank 26 can be accurately detected, and when the water supply amount detecting means 63 is configured as shown in FIG. 4, the detection accuracy can be greatly increased.

After the lapse of the delay time, the water supply amount Q detected by the water supply amount detection means 63 is input in step 95, and the motor 29 is driven. Therefore, the water tank 26
The hot water inside is supplied to the pot 14 through the water outlet 27, the pump 28, the switching valve 31, and the water outlet 33. This supply of hot water is performed until the detected water supply amount Q exceeds the water supply amount Q1 calculated in step 90 in step 96. When the supply of hot water is completed, the motor 29 is stopped in step 97, the operation of the pump 28 is stopped, and the first contact 47 is switched to the NC side so that the first heating coil 21 can be energized. As described above, since the supply of hot water into the pot 14 is a water supply amount according to the rice amount m, the rice is cooked deliciously with water suitable for the rice amount.

Next, at step 98, the pan temperature detecting means 5
3 is inputted. In step 99, it is determined whether or not the input detected pot temperature T 'has exceeded the pre-cooking temperature, for example, 50 ° C. If the temperature exceeds the pre-cooking temperature, the oscillating operation of the inverter circuit 25 is stopped in step 100, so that the high-frequency current of the inverter circuit 25 does not flow through the first heating coil 21 via the first contact 47. If the detected temperature T 'is lower than the pre-cooking temperature, the inverter circuit 25 is operated in step 101 to supply a high-frequency current to the first heating coil 21 to inductively heat the bottom of the pot 14. Then, the above operation is executed until the pre-cooking time elapses (step 102).

When the pre-cooking step is completed, the process proceeds to the rice-cooking step. First, in step 103, the inverter circuit 25 is operated to supply a high-frequency current to the first heating coil 21 and close the second contact 48 so that the The voltage of the power supply 40 is applied to the lid heater 19 and the side heater 22. Therefore, pot 1
4 has its bottom portion induction-heated by a first heating coil 21;
The side of the pot 14 is a side heater 22 and the inner lid 20 is a lid heater 1.
At 9 each is heated. In step 104, the detected pan temperature T 'of the pan temperature detecting means 53 is inputted, and in step 105
Then, the detected pan temperature T ′ is the cooking end temperature, for example, 12
If it is determined that the temperature has exceeded 0 ° C., the operation of the inverter circuit 25 is stopped in step 106, and the heating operation by the first heating coil 21 ends (end of the rice cooking process).

When the rice cooking process is completed, a warming process is performed. That is, in step 107, the pan temperature detecting means 53
If it is determined in step 108 that the input detection pot temperature T 'has exceeded the heat retention temperature, for example, 80 ° C., the second contact 48 is opened in step 109,
The heating of the lid heater 19 and the side heater 22 is stopped. On the other hand, if it is determined in Step 108 that the detected pot temperature T 'is 80 ° C. or less, the second contact 48 is closed in Step 110 and the lid heater 19 and the side heater 22 are closed. The heater 22 is heated. As described above, in the heat retaining step, heating and stopping of the lid heater 19 and the side heater 22 are repeated to maintain the heat retaining temperature.

As described above, in this embodiment, the amount of rice is detected by using the distortion amount measuring device 62 shown in FIG. 6, but as the rice amount detecting means, the amount of rice cooked by the user is input from the input unit. The rice amount may be detected from the input unit, and the rice amount may be detected from the input unit. Alternatively, the rice amount in the pan may be physically detected or input by the user so that the rice amount in the pan can be recognized. good.

The water supply amount detecting means has the structure shown in FIG. 4. In addition, the driving time of the motor 29 for driving the pump 28 is measured, and the water is supplied into the pot based on the measured time. The amount of water supply can also be detected. In addition, if the water supply capacity per unit time of the pump 28 is constant, the amount of water sent from the pump 28 during the time the pump 28 is driven, that is, the amount of supplied water, can be detected. Further, the water supply amount detecting means is not limited to the above two examples, but may be any as long as it can physically detect the water supply amount.

The means for heating the pan 14 is not limited to the first heating coil 21.
A gas combustor may be used. In short, any gas combustor can be used as long as the pot 14 can be heated.

Further, the second heating coil 36 is used as a water supply heating means to heat the water in the detachable water tank 26. For example, as shown in FIG. A heater 111 is wound around the outer periphery of
The structure which heats the water which passes through the inside of the water supply winding 30 may be sufficient, and what is necessary is just the structure which heats the water supplied into the pot 14.

[0038]

As is apparent from the above embodiment, the present invention uses hot water as the water supplied to the pot by the hot water supply means, and raises the temperature in the hot pot with the hot water. In the cooking process, it takes only one hour to raise the temperature in the pot to the pre-cooking temperature, thereby shortening the time of the pre-cooking process, and reducing uneven water absorption of rice in the pre-cooking process. Not only can cooking unevenness be reduced, but the water supply temperature to the pot is determined according to the amount of rice in the pot, so even when the amount of rice in the pot is large, the temperature in the pot after hot water is Without significantly lowering the cooking temperature,
Therefore, it is possible to minimize the length of the pre-cooking process time due to the influence of the amount of rice.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a rice cooker according to one embodiment of the present invention.

FIG. 2 is a sectional view of the rice cooker.

FIG. 3 is a sectional view showing an example of the rice quantity detecting means.

FIG. 4 is a block diagram showing an example of the water supply amount detecting means.

FIG. 5 is a flowchart showing control contents of the control means.

FIG. 6 is a flowchart showing control contents of the control means.

FIG. 7 is a sectional view of a main part of a rice cooker according to another embodiment of the present invention.

FIG. 8 is a sectional view of a conventional rice cooker.

[Explanation of symbols]

 14 pan 21 first heating coil (pan heating means) 26 water tank 28 pump (water supply device) 36 second heating coil (water supply heating means) 52 control means 53 pan temperature detecting means 54 water supply temperature detecting means 55 rice quantity Detection means 63 Water supply amount detection means 70 Process storage means 78 Water supply temperature determination means 79 Water supply amount determination means

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) A47J 27/00 109

Claims (1)

(57) [Claims] 1. A pot heating means for heating a pot, a rice quantity detecting means for detecting an amount of rice in the pot, a water tank for storing water, and a water supply for supplying water from the water tank to the pot. An apparatus, a water supply heating means for heating water supplied to the pot from the water supply apparatus, a water supply, a pre-cooking, a step storage means for storing control contents of a rice cooking process, and a control content of the step storage means. Therefore, the pan heating means, water supply device, control means for controlling the feed water heating means, the control means,
The water supply device before the start of the pre-cooked step operates the feedwater heater means supplies hot water to the pan, the hot water
Temperature in the pot from the pre-cooking temperature when rice and rice are mixed
Is in order to prevent the greatly reduced, high feed water temperature of the hot water the water supplied into the pot when the detection rice of the rice quantity detecting means is larger
A rice cooker that can be used.