KR100207071B1 - Control method of heater for microwave oven - Google Patents

Abstract

The present invention relates to a heater driving control method of a microwave oven, when a convection function and a grill function are input in a microwave oven that does not include a temperature sensor for detecting an internal temperature of a cooking chamber, the heater 20 after initial driving of the heater 20. The initial driving time determination step (S20) of determining whether the initial setting time of approximately 10 minutes has elapsed, and the overheating of the inside of the cooking chamber 11 can be prevented when the initial driving time of the heater 20 has passed approximately 10 minutes. The controller 100 controls the heater driver 130 to stop driving the heater 20 so that the heater driving stop step S22 and the heater driving stop step S22 cause the controller 20 to stop driving. Heater stop time of the heater 20 as a result of the determination of the heater stop time determination step (S24) and the heater stop time determination step (S24) to determine whether the 100 has passed approximately 1 minute, which is the heater stop time of the heater 20 After approximately one minute has elapsed, place it on the tray (17). The heater 20 controls the heater driving unit 130 so as to heat the food again, and the heater 20 according to the heater re-operation step S26 and the heater re-drive step S26. After re-driven), if the heater re-drive time of the heater 20 has not elapsed approximately 4 minutes, the flow returns to the heater re-drive step S26 and if the heater re-drive new time of the heater 20 has passed approximately 4 minutes. The heater repeating operation determination step (S30) is repeated to repeat the operation to return to the heater driving stop step (S22) until the end of cooking time.

Description

Heater drive control method of microwave oven

The present invention relates to a method for controlling the heater operation of a microwave oven. In particular, in a microwave oven which is not equipped with a temperature sensor for sensing the internal temperature of the cooking chamber, the operation of the heater is stopped until the cooking end time is reached after the initial driving of the heater. The present invention relates to a heater driving method of a microwave oven capable of preventing overheating inside a cooking chamber by repeatedly performing driving again.

In general, the microwave oven is a cooker using the principle that the food in the metal casing generates heat by its own molecular motion using electromagnetic waves of approximately 2450 MHz. In such a microwave, radio waves of about 2450 MHz are oscillated in the magnetron and induced into the case, and the molecules constituting the food are charged with + and-by the induced high frequency. At this time, one side of the molecule is charged with-on the + side of the electric field due to radio waves, and the other side of the molecule is charged with + on the-side of the electric field. However, since the polarity of the electric field changes 2.45 billion times per second due to high frequency radio waves, food molecules are severely collided with each other, causing frictional heat to heat the food. The microwave oven also has a function of cooking using convective heat and radiant heat generated by the heater by mounting a heater inside the cooking chamber.

1 is a longitudinal sectional view of such a conventional microwave oven. As shown in FIG. 1, the microwave oven according to the prior art includes a cooking chamber 11 in which food is stored and cooked, and an electrical component chamber 14 in which electrical parts for irradiating high frequency radio waves to the cooking chamber 11 are installed. A door (not shown) is provided on the front of the cabinet 10 and the cooking chamber 11. A magnetron 15 for generating high frequency radio waves and a high voltage transformer 13 for supplying a high voltage to the magnetron 15 are provided inside the electrical equipment compartment 14, and the magnetron 15 is located behind the electrical equipment compartment 14. A cooling fan 16 for cooling the overpressure transformer 13 is installed.

In addition, a heater 12 for cooking food using heat is provided above the cooking chamber 11, and a terminal portion 12a for receiving electric power is formed at the right end of the heater 12. A fixing device is installed in the terminal part 12a to change the heater 12 to a horizontal position or a vertical position, and the heater 12 is changed to a horizontal position or a vertical position to perform various cooking. In addition, a tray 17 on which food is placed is provided below the cooking chamber 11, and the tray 17 is rotated by the driving of the motor 18 provided at the bottom of the cooking chamber 11.

An operation of the microwave oven according to the related art having such a configuration will be described. First, when the user turns on the cooking start key provided on the operation panel installed in the front of the cabinet 10 and selects a desired cooking type, the magnetron 15 and the heater 12 are driven simultaneously or individually according to the cooking type. . That is, when general cooking is selected by the user, the magnetron 15 is driven to irradiate high frequency radio waves to the cooking chamber 11 to cook the food stored in the tray 17, and the user draws or convections. When the selection is made, cooking is performed by heating the food with the heater heat by driving the heater 12. As described above, in the microwave oven according to the related art, the magnetron 15 and the heater 12 are driven to cook food placed on the tray 17 according to the cooking type selected by the user.

However, when the microwave oven according to the related art does not have a temperature sensor inside the cooking chamber 11, when the internal temperature of the cooking chamber 11 rises above the reference temperature, the overheating of the cooking chamber 11 and the heater 12 may occur. The driving stop time of the heater 12 for preventing excessive driving could not be determined. Accordingly, when cooking the food by the heater heat of the heater 12, as the cooking is performed by continuously driving the heater 12 until the end of cooking, the interior and the door of the cooking chamber 11 are overheated, so that the user may open the door. If the door is touched or opened immediately after the end of cooking, the hot air in the cooking chamber 11 is directly applied to the user, causing discomfort or severe burns.

Accordingly, the present invention has been made to solve the above problems, an object of the present invention is to provide a convection function and a grill function input by the user in a microwave oven that does not have a temperature sensor for sensing the temperature inside the cooking chamber In this case, the heater driving control method of the microwave oven is provided to prevent the overheating of the inside of the cooking chamber by repeatedly operating the heater until the end time of cooking until the end of cooking time is reached. Is in.

1 is a longitudinal sectional view showing the configuration of a conventional microwave oven.

Figure 2 is a longitudinal cross-sectional view showing the configuration of a microwave oven applied to the present invention.

3 is a control block diagram of a microwave oven applied to the present invention.

4 is a flowchart illustrating a heater driving control method of a microwave oven according to the present invention.

* Explanation of symbols for main parts of the drawings

10 cabinet 11 cooking chamber

12, 20: heater 12a, 20a: terminal portion

13: high voltage transformer 14: electrical equipment room

15: magnetron 16: cooling fan

17 tray 18 motor

100: control unit 110: input power unit

120: display unit 130: key operation unit

140: magnetron driving unit 150: heater driving unit

The object of the present invention as described above is a heater installed on the upper side of the cooking chamber, a heater driving unit for driving the heater, a key operation unit for receiving the desired cooking type and cooking time from the user, and controls the driving and driving stop of the heater The controller may be configured to heat the food placed in the tray of the cooking chamber by continuously driving the heater according to the cooking time input through the key manipulation unit without the temperature sensor detecting the internal temperature of the cooking chamber. In the microwave heater control method of the microwave oven, when the convection function and the grill function is input through the key input unit, the time counted from the initial driving time of the heater is approximately 10 minutes, which is the initial driving time of the heater. An initial driving time determining step of determining whether the controller has passed; The control unit may prevent the overheating of the inside of the cooking chamber when the time counted from the initial driving time of the heater passes about 10 minutes, the initial driving time of the heater, as a result of the determination of the initial driving time determining step. A heater driving stop step of driving and stopping the heater by controlling a driving unit; In the case where the heater is stopped by the heater driving stop step, the heater stop time judging step of determining whether the time counted from the time when the control unit stops driving the heater has passed about 1 minute, the heater stop time of the heater ; As a result of the determination of the heater stop time determining step, the control unit may reheat the food placed on the tray when the time counted from the time when the heater is stopped is driven after approximately 1 minute has elapsed. A heater re-driving step of controlling the heater driving unit to re-drive the heater; And determining whether the counted time from the time of restarting the heater according to the heater restarting step has passed about 4 minutes, which is the heater restarting time of the heater, and not passing approximately 4 minutes of heater restarting time of the heater. If not, after about 4 minutes of returning to the heater restarting step of restarting the heater, the operation of returning to the heater driving stop step is completed. This is accomplished by a heater repeating drive determination step that repeats until time is reached.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a longitudinal sectional view showing the configuration of a microwave oven applied to the present invention, and FIG. 3 is a control block diagram of the microwave oven applied to the present invention.

As shown in FIG. 2 and FIG. 3, the microwave oven applied to the present invention is provided with a cooking chamber 11 in which food is stored and cooked, and an electrical equipment chamber 14 in which electrical parts for irradiating high frequency to the cooking chamber 11 are installed. The outer case (10b) coupled to the inner case (10a) forming the cabinet 10, the inner case (10a) forming the cooking chamber 11, the outer surface of the cabinet (10b) combined with the inner case (10a) And a heater 20 rotatably installed above the cooking chamber 11 and a tray 17 installed below the cooking chamber 11 to place food therein.

A magnetron 15 for irradiating high frequency and a high voltage transformer 13 for supplying a high voltage to the magnetron 15 are provided inside the electrical equipment compartment 14, and the magnetron 15 is located behind the electrical equipment compartment 14. ) And a cooling fan (not shown) for cooling the high voltage transformer 13 is installed.

A terminal portion 20a for receiving electric power is formed at the right end of the heater 20, and a fixed terminal is installed at the terminal portion 20a to maintain the heater 20 in a horizontal position or a vertical position. . One end is coupled to the terminal portion 20a, and the shaft 21 having the other end extended out of the outer case 10a is installed, and the heater 20 is horizontally positioned at the other end of the shaft 21 from the outside. Or the position change knob 22 for changing to a vertical position is provided.

The shaft 21 has a cross shape (+) to reinforce the distortion when changing the vertical position and the horizontal position of the heater 20, the handle 22 is supplied with power to the heater 20 It is made of plastic material to prevent the conduction of heat during heat generation.

3 is a control block diagram of a microwave oven applied to the present invention. As shown in Figure 3, after the initial drive of the heater 20, the control unit 100 for controlling the operation of repeating the driving stop and re-drive of the heater 20 until the end of cooking time, and An input power supply unit 110 for supplying power to each unit, a key operation unit 130 for receiving a desired cooking type and cooking time from a user, a display unit 120 for displaying the operation state and cooking type of the current microwave oven; And a magnetron driver 140 driving the magnetron 15 under the control of the controller 100, and a heater driver 150 driving the heater 20 under the control of the controller 100.

The control unit 100 receives the cooking type selected by the user through the key operation unit 130 to selectively drive the magnetron 15 and the heater 20. For example, when the convection function or the grill function is selected, the controller 100 controls the heater driving unit 150 to drive the heater 20. Accordingly, the heater 20 receives heat and generates heat, and the food placed on the tray 17 is heated by the heater heat.

As such, when cooking is started by driving the heater 20, the controller 100 stops driving and restarts the heater 20 before a cooking end time input by the user through the key input unit 130. Will be performed repeatedly. That is, the controller 100 drives the heater 20 as an example of the heater stop time by controlling the heater driving unit 150 when 10 minutes have elapsed after the heater 20 is driven as an example. After stopping, for example, the heater restarting time of the heater 20 is repeatedly performed for 4 minutes.

The heater driving control method of the microwave oven according to the present invention having the above configuration will be described in detail with reference to FIG.

4 is a flowchart showing a heater driving control method of a microwave oven according to the present invention. First, when power is applied to the microwave oven in step S10, in step S11, a user opens a door installed in front of the cooking chamber 11, places food in the tray 17, closes the door, and then closes the key. The desired cooking type and cooking time are input through the operation unit 130. At this time, if the cooking type selected by the user drives the heater 20 to heat and cook the food by the heater heat and selects the black or convection function, the process proceeds to step S14.

Subsequently, in step S14, the control unit 100 determines whether the operation is on, that is, the operation start signal is input from the key input 130 as the user selects the cooking start key of the key operation unit 130. Determine if it is.

If the operation start signal is not input from the key operation unit 130 as a result of the determination in step S14, the process returns to step S10 to wait for the user to select a cooking start key. On the other hand, when the operation start signal is input from the key input unit 130 as a result of the determination in step S14, in step S16, the control unit 100 can cook the food placed on the tray 17 in the heater. The heater 150 is driven by controlling the driver 150.

Accordingly, the heater 20 is driven by receiving electric power through the terminal portion 20a of the end portion, and the heater 20 generates heat.

Subsequently, in step S18, the control unit 100 determines whether the cooking end time has been reached. The control unit 100 counts the time counted from the initial driving time of the heater 20. It is determined that the cooking end time is reached if the cooking time input through the match with the cooking end time is matched.

If the time counted from the initial driving time of the heater 20 reaches the cooking end time as a result of the determination in step S18, the process proceeds to step S32 to stop heating of the food placed on the tray 17. Done. On the contrary, if the time counted from the initial driving time of the heater 20 does not reach the end of cooking time as a result of the determination in step S18, the controller 100 may initialize the heater 20 in step S20. It is determined whether the time counted from the driving time has elapsed 10 minutes as an example of the initial driving time (A minutes). Here, the initial set time (A minute) is a time required to raise the food to heat enough to heat the food because the internal temperature of the cooking chamber 11 is maintained at room temperature, the heater (for about 10 minutes) 20, the inner temperature of the cooking chamber 11 is within a reference temperature so that the inside of the cooking chamber 11 is not overheated.

Subsequently, when the time counted from the initial driving time of the heater 20 does not pass the initial driving time (A minute) as a result of the determination of step S20, step S16 so that the heater 20 can be restarted. On the other hand, when the time counted from the initial driving time of the heater 20 has passed the initial driving time (A minute) as a result of the determination in step S20, the control unit 20 at step S22 The heater driving unit 150 is controlled to stop the driving of the heater 20. The heater 20 is cut off from the power supplied to the terminal unit 20a so that heat generation is stopped.

Subsequently, in step S24, the controller 100 determines whether the counted time elapses from the time at which the heater 20 is driven to stop has passed the heater stop time (B minutes). Here, the heater stop time (B minutes) is determined according to the cooking time input by the user in step S12 so as to prevent overheating of the inside of the cooking chamber 11 due to continuous driving of the heater 20. The heater 20 is stopped for approximately one minute.

As a result of the determination in step S24, when the time counted from the time at which the heater 20 is driven is stopped does not pass approximately one minute, which is the heater stop time (B minutes), the heater 20 may be driven to stop. While returning to step S22, when the time counted from the time when the heater 20 is stopped driving is approximately 1 minute, which is the heater stop time (B minute), as a result of the determination in step S24, step S26. In this case, the controller 100 controls the heater driving unit 150 to reheat the food placed on the tray 17 to re-drive the heater 20.

Subsequently, in step S28, the controller 100 determines whether the time counted from the initial driving time of the heater 20 reaches the end of cooking time.

As a result of the determination in step S28, when the time counted from the initial driving time of the heater 20 reaches the cooking end time, the process proceeds to step S32 so that heating of the food placed on the tray 17 can be stopped. do. On the contrary, when the time counted from the initial driving time of the heater 20 does not reach the end time of cooking as a result of the determination in step S28, the controller 100 restarts the heater 20 in step S30. It is determined whether the time counted from the time of driving has passed the heater re-drive time (C minutes). Here, the heater re-drive time (C minutes) is determined according to the cooking time input by the user in step S12 so as to reheat the heater 20 to heat the food placed in the tray 17. The heater 20 is restarted for 4 minutes.

As a result of the determination in step S30, if the time counted from the time when the heater 20 is restarted does not pass approximately 4 minutes, which is the heater restarting time (C minutes), the heater 20 may be restarted. While returning to step S26, when the counted time from the time when the heater 20 is restarted passes about 4 minutes as the heater restarting time (C minutes), the cooking chamber is returned to step S26. (11) The flow returns to step S22 to prevent overheating inside.

Subsequently, steps S22, S24, S26, S28 and S30 are repeatedly performed until the time counted from the initial driving time of the heater 20 reaches the cooking end time.

On the other hand, when the time counted from the initial driving time of the heater 20 reaches the cooking end time as a result of the determination in step S18, or counted from the initial driving time of the heater 20 as a result of the determination in step S28. When the time has reached the end of cooking time, in step 32, the control unit 100 controls the heater driving unit 150 to stop driving the heater 20 to heat the food placed on the tray 17. It stops and ends cooking.

As described above, in the present invention, when the heater is heated to perform the convection function and the grill function, since the heater is initially driven for approximately 10 minutes, it takes about 10 minutes to rise to the extent that the food can be heated. Until the cooking end time entered by the user is reached, the heater is stopped for approximately one minute and the heater is restarted for approximately four minutes to prevent overheating inside the cooking compartment, thereby preventing the user from touching the door. In addition, hot air is directly applied to the user when the door is opened immediately after the end of cooking, and thus, the user may feel uncomfortable or burned, thereby improving the safety of the user and improving the reliability of the product.

Claims (1)

A heater 20 installed above the cooking chamber 11, a heater driver 150 driving the heater 20, a key operation unit 130 for receiving a desired cooking type and cooking time from a user, and the heater And a control unit 100 for controlling driving and stopping of the driving unit 20, and not having a temperature sensor for sensing the internal temperature of the cooking chamber 11, according to the cooking time input through the key operation unit 130. In the heater driving control method of the microwave oven to drive the heater 20 continuously to heat the food placed on the tray 17 of the cooking chamber 11, the key input unit 130 through the convection function If the grill function is input, the control unit 100 determines whether the time counted from the initial driving time of the heater 20 has passed the initial driving time of about 10 minutes, which is the initial driving time of the heater 20 (S20); As a result of the determination of the initial driving time determining step (S20), when the time counted from the initial driving time of the heater 20 passes about 10 minutes, which is the initial driving time of the heater 20, the inside of the cooking chamber 11 A heater driving stop step (S22) of controlling the heater driving unit 130 to stop driving the heater 20 so as to prevent overheating; When the heater 20 is driven to stop by the heater driving stop step (S22), the time counted from the time when the controller 100 stops driving the heater 20 is the heater stop of the heater 20. A heater stop time determining step (S24) for determining whether approximately 1 minute has elapsed; As a result of the determination of the heater stop time determining step (S24), when the time counted from the time at which the heater 20 is stopped is driven, the heater stop time of the heater 20 passes about 1 minute, A heater re-driven step (S26) of controlling the heater driving unit 130 to re-drive the heater 20 so as to heat the placed food again; And determining whether the time counted from the time when the heater 20 is restarted according to the heater restarting step (S26) has passed about 4 minutes, that is, the heater restarting time of the heater 20. If the heater restart time of about 4 minutes has not elapsed, the process returns to the heater restarting step (S26) of restarting the heater 20, while the heater restart driving time of the heater 20 is approximately 4 minutes. After the elapse of the heater operation stop step (S22) is characterized in that it comprises a heater repeating drive determination step (S30) to repeat until the cooking end time input through the key operation unit 130 is reached. Heater drive control method of the microwave oven.