JPH0421994B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic heating cooker equipped with a sensor.

Conventional technology In recent years, due to remarkable advances in semiconductor technology in various heating devices such as electric ovens, microwave ovens, and gas ovens, automatic heating cookers that memorize the control temperature and heating time in the heating chamber and automatically control heating are now available. has developed.

A conventional heating device of this type will be explained. FIG. 5 is a diagram showing the relationship between the temperature inside the heating chamber and the heating time of a conventional automatic heating device. When food is placed in the heating chamber and cooking begins, a timer in the control unit measures the time (referred to as t ₁ ) until the temperature in the heating chamber reaches the detected temperature, and when it reaches the detected temperature, A ₁ + k ₁ t ₁ ( A ₁ , k ₁
is a constant) and determine this as the total cooking time.
After reaching the control temperature, maintain the control temperature and A ₁ +
k ₁ t Cooking was finished ₁ hour after the start of cooking.

According to this method, when the rise time of the internal temperature to the control temperature is short, t ₁ k ₁ is also small and the overall cooking time can be shortened, and conversely, when t ₁ is long, the cooking time is also long. Therefore, even if the temperature rise speed in the heating chamber changes due to fluctuations in the input voltage or the environment in which it is used, the finished product of the food can be kept uniform to a certain extent.

Problems to be solved by the invention However, in such an automatic heating device,
The ability to raise the internal temperature of food and the ability to properly brown the surface of the food is required, but the following problems have been encountered.

(1) If the temperature rise time in the heating chamber is short (when the input voltage exceeds the rating or when the room temperature is high), k ₁ t ₁ will be short, but in this case, the browning will be good, but the internal temperature will be low. It often happens. This is because the controlled temperature is reached quickly, resulting in good browning, but the overall cooking time is short and the cooking ends before the heat penetrates into the food.

(2) If the rise time of the temperature inside the heating chamber is long (when the input voltage is lower than the rating or when the room temperature is low), k ₁ t ₁ will be longer, but in this case, the internal temperature will be high enough, but the browning will be too high. There are many.
This is because k ₁ t ₁ becomes longer and the time from reaching the control temperature to the end of cooking is longer, resulting in excessive browning.

(3) After reaching the control temperature, the temperature inside the heating chamber is maintained at the control temperature by intermittent operation of the heater, but the efficiency of the heater is poor and the cooking time becomes longer.

The present invention solves the above-mentioned drawbacks and provides an automatic heating cooker that does not affect the finished food even when input voltage, environment, and load change.

Means for Solving the Problems In order to solve the above-mentioned problems, the automatic heating device of the present invention provides a first heating chamber installed at the top of the heating chamber when the temperature inside the heating chamber detected by the temperature sensor reaches the control temperature. heater and a second heater installed at the bottom of the heating chamber.
The output ratio of the heaters is changed from 2:1 to 1:2.

Effect By being able to change the output ratio of the two heaters mentioned above, the time it takes for the temperature in the heating chamber to reach the control temperature can be adjusted to increase the internal temperature of the food and increase the browning of the food. The output should be distributed (2:1 distribution), and after the temperature in the heating chamber reaches the control temperature, the output should be distributed (1:2 distribution) between the upper and lower heaters, which mainly increases the internal temperature of the food. is possible. With such a control sequence, even if the temperature in the heating chamber rises quickly and the overall cooking time is short, once the temperature in the heating chamber reaches the control temperature, the heater power is used only to increase the internal temperature of the food. Because the internal temperature is high, the food will be well browned, and even if the heating chamber is slow to rise and the overall cooking time is long, the output distribution will not cause much browning once the control temperature is reached. So it won't get too burnt.

Furthermore, with this control, there is no need to maintain the temperature in the heating chamber at a controlled temperature by intermittent heating, so power can be used more efficiently and the overall cooking time can be shortened compared to conventional methods. It is.

Embodiment Hereinafter, an embodiment of the present invention will be described based on the drawings.

FIG. 1 is a side sectional view of an automatic heating cooker according to an embodiment of the present invention, and FIG. 2 is a top sectional view of the same device. 1 is a heating chamber in which the food to be heated 2 is placed and cooked; 3a is an upper heater installed on the upper surface of the heating chamber 1 to heat the food to be heated 2 from above; 3b
is a lower heater installed on the lower surface of the heating chamber 1 to heat the object to be heated 2 from below; 4 is a temperature sensor that detects the temperature inside the heating chamber; 5 is an upper heater 3a;
This is a control device that controls the output combination and cooking time of the lower heater 3b.

FIG. 3 shows an electric circuit of an automatic heating cooker according to an embodiment of the present invention. Electric power from the commercial power source 6 is supplied to the heaters 3a and 3b via a temperature switch 7 for adjusting the temperature of the heating chamber 1 and a heater changeover switch 9 for switching energization to the upper heater 3a and lower heater 3b. .

A microcomputer 11 that controls automatic control of the heating cooker receives instructions from a keyboard 13 input via an interface 12, temperature information in the heating chamber input from a temperature sensor 4 via an A/D converter 14, and the microcomputer. The first relay 8 and the second relay 10 are driven based on the time from the start of cooking counted inside the relay 11, and the corresponding temperature control switch 7 and heater changeover switch 9 are opened and closed. By doing so, the temperature in the heating chamber can be kept constant, or the time cycle of energizing the upper heater 3a and the lower heater 3b can be changed (for example, energizing the upper heater 3a for 10 seconds: the lower heater for 10 seconds repeatedly, the upper heater for 5 seconds: the lower heater). heater 15
(change to seconds) You can change the output distribution of the top, bottom, and heater.

FIG. 4 shows temporal changes in the temperature in the heating chamber of the automatic cooking device according to an embodiment of the present invention and the output state of the heater. When the food 2 is placed in the heating chamber 1 and cooking begins, the microcomputer 11 counts the time, and when the temperature inside the heating chamber detected by the temperature sensor reaches a predetermined detected temperature, the time t ₂ from the start of cooking is determined. is multiplied by a predetermined constant k ₂ and added to the predetermined constant A ₂ to determine the total cooking time (A ₂ +k ₂ t ₂ ) and stored in the storage section of the microcomputer 11. From the start of cooking until the temperature in the heating chamber reaches the predetermined control temperature, the output distribution of the upper and lower heaters is _P1 (upper heater:
Food is heated with 800W (lower heater: 400W). This output distribution of P ₁ is a well-balanced distribution that increases the internal temperature of the food and reduces browning. When the temperature in the heating chamber reaches the control temperature, the microcomputer 11
Adjust the output distribution of the lower heater to P ₂ (upper heater: 400W,
Lower heater: 800W). This power distribution of P ₂ mainly works only to increase the internal temperature of the food, and has a small distribution that works to brown the food. The device continues heating with the output distribution of P ₂ and finishes cooking when the total memorized cooking time A ₂ +k ₂ t ₂ has elapsed.

According to this cooking sequence, when the temperature in the heating chamber rises quickly (when the input voltage exceeds the rating, when the room temperature is high, when the load is low, etc.), the total cooking time is shortened, so there is no chance of overcooking. Furthermore, the internal temperature can be raised sufficiently because the heating time using the output distribution of P ₂ can be secured for a certain amount of time or more depending on how the constant A ₂ is determined. In addition, if the heating chamber temperature rises slowly (such as when the input voltage is low, the room temperature is low, or the load is high), the total cooking time becomes longer and the internal temperature of the food can be raised sufficiently, and the control temperature After reaching , the output distribution is changed to P ₂ , so it won't get too burnt. Furthermore, unlike conventional control, the heater is not turned on and off, so the output of the heater can be consumed efficiently and the cooking time can be shortened.

As described above, according to one embodiment of the present invention, after the temperature inside the heating chamber reaches the control temperature, the output distribution of the upper and lower heaters is changed, and the output distribution is changed to mainly work to raise the internal temperature of the food. Since the food is not exposed to much heat, it is now possible to cook food without any difference in the finished product even if there are fluctuations in the input voltage, environment, or load.

Effects of the Invention As described above, the automatic heating cooker of the present invention raises the temperature when the temperature inside the heating chamber reaches a predetermined control temperature.
The configuration changes the output distribution of the lower heater from 2:1 to 1:2, so even if there is a difference in the speed of temperature rise in the heating chamber due to input voltage fluctuations, environmental fluctuations, load fluctuations, etc. It does not affect the finished product and has more stable performance. Additionally, since temperature control is not performed by intermittent heating, the efficiency of the heater can be increased, making it possible to shorten cooking time.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of an automatic heating cooker according to an embodiment of the present invention, FIG. 2 is a top sectional view of the device, FIG. 3 is an electric circuit diagram of the device, and FIG. 4 is a control of the device. Sequence diagram, FIG. 5 is a control sequence diagram of a conventional automatic heating cooker. 1... Heating chamber, 3a... Upper heater, 3b...
... lower heater, 4 ... temperature sensor, 5 ... control device.

Claims (1)

[Claims] 1. A heating chamber in which an object to be heated is placed, a first heater installed in the upper part of the heating chamber to heat the food from above, and a first heater installed in the lower part of the heating chamber to heat the food from the lower part. A second heater, a control unit that controls power supply to the first heater and the second heater, and a temperature sensor that detects the temperature inside the heating chamber, the temperature inside the heating chamber being adjusted to a predetermined control temperature. An automatic cooking device characterized in that the ratio of the outputs of the first heater and the second heater is changed from 2:1 to 1:2 when the temperature reaches the desired temperature. 2. The automatic heating cooker according to claim 1, wherein the total heating time is changed depending on the time required for the temperature in the heating chamber to reach a predetermined detected temperature.