JPS6046799B2 - microwave oven - Google Patents

Description

[Detailed description of the invention] The present invention relates to a microwave oven with a rice cooking function.

Conventional microwave ovens have cooking functions such as defrosting, reheating, and stewing, but none have a rice cooking function.

However, some research has been carried out, "Cooking Science" Volume 5 No. 4 (
Although it was reported in the November 1971 issue of the Culinary Science Study Group), it had not actually been commercialized. The present invention has been made in view of these points, and provides a microwave oven equipped with a rice-cooking-specific control means that executes a highly marketable rice-cooking sequence.

According to the above research report, the rice cooking sequence is I.
・・1 conflict IKW strong output, ■・ ・ ・ O for 30 minutes
Heating control was in place with zero output of W and strong output of IKW for one minute.

According to this method, there are disadvantages in that it takes a long time to cook rice and the microwave output is large. After repeated experiments, the first
As shown in the results shown in the figure, we have found an optimal rice cooking sequence for microwave ovens that is also suitable for home microwave ovens. That is, delicious rice can be cooked in a short time and at low output using the following rice cooking sequence. "Microwave rice cooking sequence" I First high heat heating (strong output of 500 to 600 W) Tl time■ Low heat heating (low output of 180 to 300 W) T.

Time■ Second high heat heating (strong output of 500-600W)
T3 hours ■ Unevenness (0 output of OW) T.

Optimal rice cooking can be achieved by carrying out a series of heating steps 1 to 3 for more than an hour.

This rice cooking sequence can be explained theoretically as follows. Bring to a boil in the first heating step I, and then proceed to the second heating step ■
The rice is converted to β-α. In the next third heating step (2), water is removed from the rice, and in the fourth and final heating step (2), ``uniformity'' is carried out. What can be seen from Figure 1 is that better results are obtained with 4-step control than with 3-step control, as in sample number 5, and that it is better to heat with high heat rather than low heat at first, and overall The rice cooking sequence example seen in sample number 5 was extracted as a rice cooking sequence for microwave ovens.

In addition, in the experiment shown in Figure 1, 1 cup of rice was 200cc, 175
The amount of cold water used was 1.3 times that of rice.

By the way, in the above-mentioned microwave rice cooking sequence, the second heating step (3) is performed using low heat heating, and as is already known, there are the following methods for setting low heat.

One is a magnetron continuous oscillation method in which the magnetron is continuously oscillated and the oscillation intensity itself is reduced to a low output by changing the capacitance of a high-voltage capacitor.The other is to drive the magnetron in intermittent oscillation without changing the oscillation intensity, resulting in a low average output. It is a magnetron intermittent method. Therefore, an experiment was conducted to compare the quality of rice cooking when the magnetron was set to low heat with continuous oscillation and when it was set to low heat with intermittent oscillation.

This is shown in Figure 3. According to this diagram, the low heat should be
A case where both outputs of 00W and 250W are set is also considered. Based on the results of this experiment, the intermittent method received a better overall evaluation.

The reason for this is thought to be that intermittent oscillation has a stronger instantaneous output, which intensifies the convection of water in the rice cooking container and causes the rice to stand. Also, the output of 250W is better than the output of 200W. This 200W or 250W output is the same as the microwave output used for conventional stew cooking. Nao No. Figures 1 and 3 show the experimental results using 1 cup of rice at 200 cc and 260 cc of water, but the experimental results when using 2 or 3 cups of rice are as shown in Figure 4. From this result, it can be seen that only the heating time T1 of the first heating step 1 in the above rice cooking sequence can be increased depending on the number of cups. The reason is the first heating step 1, which is high heat heating.
This is thought to be a process for boiling water according to the amount of rice and water. Furthermore, in the same rice cooking sequence, I experimented with high heat heating at 600W output and low heat heating at 300W output. The results are shown in Figure 5, and the time required from the second heating step (■) to the fourth heating step (■) is T2 to T4.
The values of are the same as those of the experiments shown in FIGS. 1 to 4, but the time required for the first heating step 1 is shorter. In any case, the third heating step ■
The time T3 required for this is preferably 1 to 3 minutes, but if the timer error is taken into consideration, a value of 2 minutes is optimal. Next, a specific structure of a microwave oven that executes the above rice cooking sequence will be explained.

FIG. 6 is an external perspective view of a microwave oven which is an embodiment of the present invention. The operation panel 1 is provided with a first timer knob 2 provided for the one timer and a twelfth timer knob 3 provided for the three timer. 4 is a mode selection button to select each function of low, stew, and rice cooking; 5 is a high lamp that lights up when the first timer knob 2 is turned to set the cooking time; 6 is a mode selection button 4
7 is a low simmer lamp that lights up when the button for ``low'' or ``simmer'' modes is set, and 7 is a rice cooking lamp that lights up when the button for ``simmer rice'' mode is set.

FIG. 7 is an enlarged view of the main part of FIG. 6. The electric circuit shown in FIG. 8 is a circuit assembled in the microwave oven of the present invention, and 8 is a power plug which is inserted into an AClOOV power socket. 9 is the latch switch, 10 is the door safety switch,
When the door 11 of the microwave oven shown in FIG. 6 is opened using the door handle 12, both switches 9 and 10 are switched to the a contact side.
The open lamp 13 is turned on to illuminate the inside of the open refrigerator.

The user stores the food to be cooked in the bright open cabinet and closes the door 11. When closing the door 11, both switches 9 and 10 are switched to the b contact side. 14 is a timer reset by the first timer knob 2 shown in FIG. 6, and is used during general high-heat cooking.

After setting the first timer 14 to a desired time (maximum one batch cooking is possible since the cooking time is one batch), when the cook switch 16 is operated, the circuit shown by the thick line in FIG. 9 is activated. That is, turn the first timer knob 2 to set the first timer 1.
When the timer contacts 14a and 14b of 4 are closed,
A power supply is connected to the relay 17 through the timer contact 14b, and the relay contact 17a is closed, and a power supply is connected to the primary winding 18a of the high voltage transformer 18 through this and the timer contact 14a, which is composed of a magnetron or the like. The microwave generation circuit 19 is excited and high flame heating with an output of 500W is set. 20 is a blower motor for cooling the magnetron, and the open lamp 13 is connected to the power source via the b contact of the door safety switch 10.

The first timer 14 switches the other timer contact 14c to the B contact side according to the setting, connects the power supply itself, lights up the high-intensity lamp 5, and allows the user to perform general high-heat cooking. inform about something. 1st timer 1
4 finishes counting the set time, each of the timer contacts 14a, 14b, and 14c returns to its initial state, and the operation of the microwave generating circuit 19 and the like is stopped to finish cooking. A second timer 21 is reset by the second timer knob 3, and is set in conjunction with the mode selection button 4 for setting the above-mentioned "low,""boiling,""cooking" functions.

Now, set the desired cooking time on the second timer 21 using the second timer knob 3, and press “
If you operate the weak button, the thick line circuit in Figure 10 will work. At this time, the changeover switches 22 and 23 are set to the P1 contact side. According to this, a power source is connected to the primary winding 18a of the high voltage transformer 18 via the timer contact 21a of the second timer 21 and the disconnect switch 24, but the disconnect switch 24 is connected to the rotating shaft of the blower motor 20. The microwave generation circuit 19 is intermittently opened and closed by the rotation of a cam 25 that is rotationally driven by a speed reduction mechanism (not shown).
Since the power supply to the magnetron is controlled intermittently, the magnetron oscillates intermittently and has an average output of 200W. Furthermore, this intermittent switch 2
The interruption ratio of 4 is the ratio of closed 2:closed 3. Next, we will explain how to operate the ゜゜stewed゛ button. In this case, the thick line circuit in FIG. 11 will work. When the "゜Simmer" button is set, both the changeover switches 22 and 23 are set to the P2 contact, so the second timer 21 is connected to the power supply via the timer on/off switch 26. It opens and closes intermittently by the rotation of a cam 27 that is rotatably driven by a speed reduction mechanism (not shown) connected to the rotating shaft of the blower motor 20, and the on/off ratio is 1: closed: 4: open. Therefore, the second timer 21 rotates at a speed of 115 and switches to a timer with a maximum time measurement of 15 min. Correspondingly, the values around the second timer knob 3 are also switched to 15 min. The purpose of setting such a long timer is to use a low-output, low-heat method for heating stewed dishes over a sufficiently long period of time.
Next, a specific configuration for executing the above rice cooking sequence, which is the most characteristic feature of the present invention, will be explained. First, of the mode selection buttons 4 on the operation panel 1, press the "Cook Rice" button.Pour rice and 1.3 times as much water into a glass or ceramic container with a lid, and store it in the open refrigerator. After closing the door 11, turn the second timer knob 3 to the position corresponding to the amount of rice.As shown in FIG. 1 cup of rice for 175 da, 2 cups for 350 q, 525
The g is 3 cups. Although omitted in the above description, a rice cooking cam 28 as shown in FIG. 13 is assembled in the second timer 21 and rotates together with the second timer 21. This rice cooking cam 28 has a shape having a recess 28a formed by cutting out a part of a disc, and the actuator 30 of the rice cooking control switch 29 is brought into contact with the outer peripheral surface of the recess 28a.
This rice cooking control switch 29 is in an open state when the actuator 30 is located in the recess 28a of the rice cooking cam 28, and is set in a closed state when it is located in another high place 28b, 28b''. Now, when the second timer knob 3 is set to a position corresponding to the amount of rice, the rice cooking cam 28 rotates clockwise in Fig. 13, and the portion corresponding to the amount of rice controls the rice cooking. It is in contact with the actuator 30 of the switch 29.For convenience, the rice cooking cam 28 in FIG. When the timer 21 of 2 is set and the cook switch 16 is operated, the thick line circuit in Fig. 12 is activated and the rice cooking lamp lights up.
The second timer 21 starts operating.

Here, the changeover switches 22 and 23 are switched to the P3 contact side. According to this, the relay 17 is connected to the power source via the rice cooking control switch 29 which is in the closed state, and the relay contact 17a is closed to connect the primary winding 18a of the high voltage transformer 18.
Connect the power to the Therefore, the microwave generation circuit 19 is continuously supplied with power, and starts the first high-heat heating step 1 with an output of 500W. Here, in order to make the explanation more understandable, the time chart in FIG. 14 will be referred to. This shows the microwave output and required time for each heating step 1 to ① in the rice cooking sequence described above. Figure a shows the time chart for the amount of rice for 1 cup, diagram b for 2 cups, and diagram c for the amount of rice for 3 cups. It shows. Now, if the amount of rice is 1 cup, the first heating step 1 is started as a heating operation for 8 minutes at an output of 500 W in conjunction with the operation of the cook switch 16. The rice cooking cam 28, which is rotating back counterclockwise as the first heating step 1 progresses, brings its recess 28a to the actuator 30 after eight minutes have elapsed. Along with this, the rice cooking control switch 29 is switched to the open state, stopping the power supply to the relay 17, and therefore the power supply to the primary winding 18a of the high voltage transformer 18 is switched to the power supply path on the intermittent switch 24 side. As mentioned above, this on/off switch 24 is connected to a cam 25 that rotates in conjunction with the blower motor 20.
Since this is a switch that opens and closes with an intermittent ratio of 2/5, the microwave generating circuit 19 is driven intermittently and the second heating step (2) begins with low-heat heating with an average microwave output of 200 W. The second heating step (2) is performed in one batch. During this period, the rice-cooking cam 28 brings its recess 28a into contact with the actuator 30 while bringing the next high point 28b'' closer to it. Therefore, after one stroke, the actuator 30 moves the rice-cooking cam 28 to the high point 28b''.
is pressed, the rice cooking control switch 29 is switched to the closed state, and the third heating step (2) is performed. Third heating step■
is a period in which the second high heat heating is performed for a short time of 2 minutes.

Since the rice cooking control switch 29 is in the closed state, the relay 17 is activated again to close the relay contact 17a. Therefore, similarly to the first heating step, the microwave generating circuit 19 continuously oscillates the magnetron to perform the heating operation with a strong output of 500W. After two minutes, the second timer 21 completes its set time.

Along with this, the timer contacts 21a and 21b are respectively opened to stop power supply to the microwave generation circuit 19 and the like. However, if the heating process is repeated from the first heating process 1 to the third heating process (2). The heated rice should then be heated for at least 10 minutes.
In order to carry out the ゜muraji, the container and the container are left alone. By completing this "muraji" and completing the fourth heating step (2), delicious rice will be cooked as shown in the experimental results shown in Figures 1 to 5 above. As explained above, the feature of this rice cooking sequence is that even if the amount of rice changes, only the time required for the first heating step 1 needs to be changed, and this has resulted in a very simple structure for commercialization. I ended up being unable to make ends meet.

That is, the rice cooking cam 28 can perform rice cooking control corresponding to the amount of rice.

As shown in FIG. 13, the rice cooking cam 28 only needs to have a length on the high point 28b side that corresponds to the amount of rice. For example, if the portion of the rice cooking cam 28 where 3 cups is written is transferred to the actuator 30, the first heating step 1 is set as 1 rice cooker, and after that amount of time has elapsed, the recess 28a is transferred to the actuator 30. The process automatically moves on to the next second heating step (2). As described above, according to the present invention, rice can be cooked even in a household microwave oven, and delicious rice can be cooked. can offer a very high value microwave oven.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the experimental results of the rice cooking sequence for microwave ovens, Figure 2 is a diagram explaining the judgment criteria, and Figure 3 is the experimental results of the rice cooking sequence for microwave ovens tried by changing the oscillation method of the magnetron. Figure 4 is a diagram explaining the experimental results of a rice cooking sequence for microwave ovens tried by changing the amount of rice cooked. Figure 5 is a diagram explaining the experimental results of a rice cooking sequence for microwave ovens tried by changing the oscillation output of the magnetron. 6 is an external perspective view of the microwave oven of the present invention, FIG. 7 is an enlarged view of its main parts, FIG. 8 is an electric circuit diagram assembled in the microwave oven, and FIGS. 9 to 12 13 is an external perspective view of the rice cooking cam, and FIG. 14 is a time chart illustrating the rice cooking sequence according to the present invention. 28: Rice cooking cam.

Claims (1)

[Claims] 1. A microwave oven comprising a rice-cooking-specific control means that controls high-frequency output in the order of strong-weak-strong-zero. 2. A microwave oven that controls high-frequency output in the order of strong-weak-strong-zero, and is equipped with a dedicated control means for rice cooking that sets the weak output by intermittent high-frequency oscillation. 3. A microwave oven that controls high-frequency output in the order of strong-weak-strong-zero, and is equipped with a rice-cooking-specific control means that makes the heating time by the first strong output variable according to the amount of rice cooked.