JP2002048347A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave oven to perform proper heating cooking by preventing the occurrence of unevenness in heating due to a kind and the shape of a substance to be heated. SOLUTION: The microwave over 1 comprises a heating chamber 2 to contain a food 12; a rotatable turn table 13 on which the food 12 is placed and which is supported on a rotary shaft 8, an output variable type drive motor 6 for rotationally driving the turn table 13 through the rotary shaft 8; and a magnetron 3 to generate an electromagnetic wave for heating the food 12. An output of the magnetic wave generated from the magnetron 3 by a mode selected from a plurality of previously registered modes is decided. A control device 5 is provided to variably control the rotation speed of the drive motor 6 according to the output of an electromagnetic wave.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven, and more particularly to a microwave oven that heats food placed on a rotating turntable by electromagnetic waves from a magnetron.

[0002]

2. Description of the Related Art Conventionally, in a cooking device such as a microwave oven, a food is placed on a rotating turntable in order to eliminate uneven heating of the food which is a problem during heating and to make the distribution of heating uniform. What is heated by heating is common. That is, the food placed near the center of the turntable changes its direction only with little change in its position to absorb electromagnetic waves from various directions, while the food placed at a position away from the center of the turntable Performs a circular motion at a constant rotational speed about the rotation axis of the turntable, absorbs electromagnetic waves at various positions, and is heated.

However, in such a microwave oven, if the shape of the food to be heated is approximately the same size as the turntable tray, or if the shape of the microwave oven is such as a rectangular parallelepiped or the like having many angular portions, electromagnetic waves are not generated. It is easy to concentrate on the outer peripheral portion or the angular portion of the food, and it is difficult to obtain sufficient heating uniformity due to uneven distribution of heating. Also,
In the thawing of frozen foods, the degree of electromagnetic wave absorption differs between the frozen part and the part that has thawed and melted,
Heating of the molten portion containing a large amount of liquid moisture is promoted, and uniform thawing cannot be performed. Furthermore, when the output pattern of the electromagnetic wave at the time of heating has an ON / OFF duty, a portion that is easily heated strongly by the food in synchronization with the output of the electromagnetic wave appears remarkably. Could be

Therefore, as a technique for improving the uniformity of the heating of foods, the output of electromagnetic waves is adjusted to the rotation speed of a turntable as disclosed in Japanese Patent Application Laid-Open No. H8-100924.
JP-A-6-147489, which controls the rotation of a turntable or a turn stirrer in a chaotic manner, or JP-A-8-138856, which controls the height and rotation of a turntable. -1003
Japanese Patent Application Laid-Open No. 93-93 discloses a method of controlling the rotation of a turntable by inverter control, and a method of controlling the rotation only when the food is liquid, as disclosed in Japanese Patent Application Laid-Open No. 8-124672.

[0005]

However, in the case where the output of the electromagnetic wave is adjusted to the rotation speed of the turntable, the heating condition is stabilized by changing the output of the electromagnetic wave to obtain uniform heating. In this case, the time required for heating tends to be long,
Since there is no particular difference in the rotation of the turntable from the conventional one, it is difficult to ensure sufficient uniformity of heating.

In order to control the rotation of the turntable in a chaotic manner, the control mechanism is very complicated, and the drive motor for rotating the turntable must be a synchronous motor which is generally widely used. Therefore, there is a problem that the cost is unavoidable and cannot be applied to heating applications other than thawing.

In the case of changing the height and the rotation speed of the turntable, the height of the turntable is changed in the heating chamber.
Optimum depending on the size, shape or place of the same food even if the drive mechanism is large and the effective heating volume of the heating chamber of the microwave oven is limited, the number of movable parts is complicated and the control is complicated. Because of the different heating sequences, it is virtually impossible to achieve an appropriate heating sequence that covers all ingredients.

In this case, since the electromagnetic wave easily hits a portion where heating progresses slowly, even if the rotation speed of the turntable is arbitrarily changed during the heating operation, the portion where the heating unevenness actually occurs changes in real time. In addition, since it varies depending on the type of food, heating is not always performed while correcting the heating distribution, and it has been difficult to improve non-uniformity of heating.

Further, in the case where the rotation speed of the turntable is variably controlled by inverter control, since the rotation speed is changed in synchronization with the ON / OFF cycle of the output of the electromagnetic wave, heating is accelerated depending on the shape of the food. There is a possibility that the bias of the distribution between the part to be performed and the part that is not is rather remarkable. Therefore, it has been difficult to ensure sufficient heating uniformity for the heated food.

In addition, even if the rotation speed of the turntable is variably controlled only when the food is liquid, there is no great effect on the heating efficiency, and in particular, a uniform heating distribution can be obtained when thawing or heating solid food. There was a problem that can not be.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a microwave oven capable of preventing uneven heating due to the type and shape of an object to be heated and performing appropriate cooking. I do.

[0012]

In order to achieve the above object, the present invention provides a heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotating shaft, In a microwave oven equipped with a variable output drive motor for rotatingly driving the turntable via the rotary shaft and a magnetron for generating an electromagnetic wave for heating the food, a plurality of modes registered in advance are provided. A control device for variably controlling the rotation speed of the drive motor according to the mode selected from the above.

[0013] The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food And a magnetron that generates an electromagnetic wave, the output of the electromagnetic wave generated from the magnetron is determined by a mode selected from a plurality of modes registered in advance, and the output of the electromagnetic wave A control device for variably controlling the rotation speed of the drive motor according to

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food In a microwave oven provided with a magnetron that generates electromagnetic waves, the rotation speed of a plurality of different motors according to a mode selected from a plurality of modes registered in advance, and the number of rotations or rotation time associated with each rotation speed During the heating operation, a specific rotation speed is sequentially selected from the plurality of rotation speeds, and the drive motor is drive-controlled until the number of rotations or the rotation time corresponding to the rotation speed is reached. A control device is provided.

[0015] The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food In a microwave oven provided with a magnetron that generates electromagnetic waves, a heating time is set according to a mode selected from a plurality of modes registered in advance, and a plurality of times associated with a plurality of predetermined time zones are set. And a controller for controlling the drive motor by selecting a drive time corresponding to the heating time from the drive motor rotation speed.

In the microwave oven according to the present invention, the plurality of modes are at least one of a kind, a shape, and a weight of the food.

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food In a microwave oven provided with a magnetron that generates electromagnetic waves, a state detecting unit that detects a state of the heated food, and based on a detection result of the state detecting unit, variably controls a rotation speed of the drive motor during a heating operation. A control device is provided.

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food In a microwave oven provided with a magnetron that generates electromagnetic waves, a temperature detecting means for detecting the temperature of the heated food, and based on a detection result of the temperature detecting means, variably controls a rotation speed of the drive motor during a heating operation. A control device is provided.

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food In a microwave oven provided with a magnetron for generating electromagnetic waves, a position detecting means for detecting the position of the heated food, and variably controlling a rotation speed of the drive motor during a heating operation based on a detection result of the position detecting means. A control device is provided.

The microwave oven according to the present invention is characterized in that the rotational speed of the drive motor is changed stepwise every time a predetermined time elapses.

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food And a magnetron that generates an electromagnetic wave, the output of the electromagnetic wave emitted from the magnetron is intermittently switched at a predetermined cycle, and during the period when there is no output, the drive motor is not driven. A control device for stopping rotation or changing the rotation speed is provided.

In this case, the stop time of the output of the electromagnetic wave is changed by selecting or calculating the rotation speed of the turntable from a registered value based on a known stop time, and changing the rotation speed at the time of the next output of the electromagnetic wave. If the position of the table is controlled to match the position of the turntable when the output of the electromagnetic wave is stopped, the uniformity of heating can be improved.

The present invention also provides a heating chamber for containing food,
A rotatable turntable on which the food is placed and supported by a rotating shaft, a variable output drive motor for rotating the turntable via the rotating shaft, and a heater for heating the food And a magnetron that generates an electromagnetic wave, the output of the electromagnetic wave emitted from the magnetron is intermittently switched at a predetermined cycle, and during the period when the output is present, the drive motor A control device for changing the rotation speed is provided.

According to the above configuration, the output of the magnetron and the rotation speed of the turntable are appropriately changed during the heating operation in accordance with the type, shape or weight of the food, or the temperature of the food, on the turntable. Food can be heated.

Further, the microwave oven according to the present invention includes a rotation operation section for setting the rotation speed of the drive motor by a rotation operation, and determines the rotation speed of the rotation operation section and the set rotation speed of the drive motor. It is characterized in that it is made to correspond. According to this, the rotation speed of the drive motor can be set quickly and intuitively by the rotation operation of the rotation operation unit.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <First Embodiment> A first embodiment of the present invention
An embodiment will be described with reference to the drawings. Figure 1
1 is a schematic sectional view of a microwave oven according to the present embodiment.
In FIG. 1, 1 is a microwave oven main body, 2 is a heating chamber for accommodating food 12, 3 is a magnetron that oscillates an electromagnetic wave for heating, and 4 is a waveguide for guiding the electromagnetic wave oscillated from the magnetron 3 into the heating chamber 2. The tube 5 is a control unit for controlling the heating operation.

Reference numeral 6 denotes a drive motor composed of a synchronous motor. The motor shaft 6a has a first shaft having a relatively small outer diameter.
The gear 9 is inserted through the center of rotation. Reference numeral 13 denotes a turntable on which the food 12 to be heated is placed. The turntable 13 is detachably fixed to a turntable support 14 supported at the upper end of the shaft 8 inserted through the rotation center of the second gear 10. Reference numeral 19 denotes a roller unit provided on the periphery of the turntable support unit 14.

The meshing teeth of the first gear 9 mesh with the meshing teeth of the second gear 10 having an inner diameter larger than that of the first gear 9, and the rotation of the drive motor 6 is controlled by the motor shaft 6a and the first gear 9. Is transmitted to the shaft 8 via the second gears 9 and 10, and the turntable support portion 14 is rotated by the roller portion 19 with the rotation of the shaft 8, so that the turntable 1 is rotated.
3 is designed to rotate.

The lower end of the shaft 8 is supported by weight detecting means 7 which also serves as a bearing. Reference numeral 11 denotes a fan for cooling the magnetron 3 and blowing air into the heating chamber 2. Reference numeral 20 denotes an operation panel provided on the exterior of the microwave oven main body.
As shown in the figure, the weight detection means 7 and the operation panel 20 are connected to the input side of the control unit 5, and the magnetron 3, the drive motor 6 and the fan 11 are connected to one output side.

The drive motor 6 is generally a synchronous motor and is driven at a commercial frequency (50 Hz or 60 Hz) in many cases. In the following embodiment, the rotation of the turntable 13 used at the commercial frequency is usually performed. In order to maintain the speed, the rotation speed of the drive motor 6 is changed according to the gear ratio of the first and second gears 9 and 10 so that the same rotation speed can be obtained. The drive motor 6 is not limited to a synchronous motor, and may be another means that satisfies the conditions for implementing the present invention, such as an induction motor. The control unit 5 converts an AC voltage input at a commercial frequency into a DC voltage once, then converts it into an arbitrary frequency, and then supplies the DC voltage to the drive motor 6 to drive it.

FIG. 2 is an enlarged view of the operation panel 20.
A display unit 22 formed of a liquid crystal or the like is formed at a substantially center in the shape of a rectangular window, and a rotation operation unit 21 for inputting by rotating a knob is provided below the display unit 22. A start button 23 is provided.

Thus, the user places the food on the turntable 13 (FIG. 1) in the heating chamber 2 (FIG. 1) and operates the rotary operation unit 21 to display the food on the display unit 22. After selecting a desired one from the heating menu and the type of food, the heating operation can be started by pressing the start button 23.

The information set on the operation panel 20 is input to the control unit 5 (FIG. 1). Based on the input, the operation unit 5 causes the food 12 (FIG. 1) on the turntable 13 (FIG. 1) to follow an arbitrary heating sequence. The operations of the magnetron 3 (FIG. 1) and the drive motor 6 (FIG. 1) are controlled so as to perform the heating cooking of FIG.

The usage of the microwave oven configured as described above will be described. Here, it is assumed that the type of food to be cooked and the cooking menu are classified in advance into liquids with a high water content, thawing, heating, and the like with as few categories as possible.

FIG. 3 is a top view of an example of a case where the food 12 selected to have a size close to the area of the turntable 13 is heated by a microwave oven. The hatched portions in the figure indicate locations where heating is excessive. When the turntable 13 is rotated while the drive motor 6 is fixed at a constant rotation speed at a normal commercial frequency, as shown in FIG. 3A, overheated portions are concentrically spaced apart in a strip shape. There are more than one.

On the other hand, the type and menu of the food 12 are selected from the operation panel 20, and the drive motor 6 is rotated at a rotation speed corresponding to the type and menu of the food 12 determined by the control unit 5 based on the input. Turntable 1
In the case where heating was performed on No. 3, excessive heating was suppressed as shown in FIG.

FIG. 4 is a comparison diagram of the finished state after heating when frozen minced meat as the food 12 is thawed while being rotated on the turntable 13. The X mark in the figure is an undecompressed portion, and the portion indicated by a dot is a portion which has not been discolored but has a high temperature. When the turntable 13 was rotated with the drive motor 6 fixed at a constant rotational speed at a normal commercial frequency, undecompressed portions were conspicuous on both sides as shown in FIG.

On the other hand, when the thawing menu is selected from the operation panel 20 and heating is performed on the turntable 13 while rotating the drive motor 6 at a rotation speed corresponding to the thawing menu determined by the control unit 5 based on this input. As a result, as shown in FIG. 4B, the undecompressed portion was reduced by about 20%.

FIG. 5 shows an example of the relationship between the rotation speed of the drive motor and the heating time depending on the type of food. The type of food 12 selected by the user on the operation panel 20 and the weight detection means 7 Based on the detected weight of the food 12, the rotation speed and the heating time of the drive motor 6 are determined by the control unit 5.
As the heating progresses while rotating 2, the food 1
A highly uniform heating operation according to the two types and weights can be realized.

In addition to the type and weight of the food 12,
Since the ideal heating conditions also differ in the strict sense depending on the shape of the food, in this case, the food 1 is changed from several pre-registered shapes (for example, a cylinder or a rectangular parallelepiped).
If a shape close to the shape 2 can be selected from the operation panel 20, a highly uniform heating operation according to the shape of the food 12 can be realized.

FIG. 6 shows an example of the relationship between the output of electromagnetic waves during heating depending on the type of food and the rotational speed of the drive motor. In this diagram only, there is a substantially proportional relationship between the two. Holds. In this case, the output of the electromagnetic wave generated from the magnetron 3 is determined according to the type of the food 12 selected by the operation panel 20, and the control unit 5 variably controls the rotation speed of the drive motor 6 according to the output of the electromagnetic wave. Has become.

Thus, the food 12 is heated while being rotated on the turntable 13 by the output of the electromagnetic wave determined by the type of the food 12 and the rotation speed of the drive motor 6 based on the output. Control becomes possible. Therefore, the uniformity of heating is improved. Further, the weight and shape of the food 12 may also be input to the control unit 5 as information for determining the heating condition.

FIG. 7 shows an example of a change in the rotation speed of the drive motor 6 when the food is heated. When the type of the food 12 is selected by the operation panel 20, a heating sequence registered corresponding to the food 12 is called and executed. In the example of FIG. 7, after heating the food 12 on the turntable 13 for L rotations at a specific Y rotation speed for a predetermined time ty from the start of the heating, the specific time different from the predetermined time tx, Y An operation of performing M rotation heating at the rotation speed X is periodically repeated until the heating is completed.

As a result, the food 12 is heated on the turntable 13 whose rotation speed fluctuates periodically. Therefore, the position of the portion where the electromagnetic wave applied to the food 12 is easily absorbed, that is, the position of the strongly heated portion of the food 12 is shifted by the rotation of the turntable 13, so that the uneven heating of the food 12 is prevented, and the uniform heating is achieved. The performance is improved.

FIG. 8 shows an example of the relationship between the food heating time and the rotation speed of the drive motor during heating. When the user directly inputs the heating time from the operation panel 20, or when the heating time is determined by detecting the weight of the food 12, when the heating is started, the set heating time (t
A, tB, or tC) is determined within any of the pre-registered time zones (0 to t1, t1 to t2, t2 to t3,...), And in the case of the heating time tA, The rotation speed of the drive motor 6 is determined as the rotation speed A, the rotation speed B for the heating time tB, and the rotation speed C for the heating time tC.

In this way, when the heating time is relatively short, the turntable 13 is rotated at a high rotation speed to heat the food 12 with priority on heating, and when the heating time is long, the rotation speed is reduced at a low rotation speed. By rotating the turntable 13, heating of the inside of the food 12 is promoted, and uneven heating can be reduced.

FIG. 9 shows an example of the relationship between the drive motor, the rotation speed, and the cooking time for each cooking menu. In accordance with menus that can be selected by the user from the operation panel 20, heating sequences for cooking various types of foods 12 are registered in the control unit 5, and the user can select an appropriate one from these menus. Thus, the food 12 can be easily cooked.

However, it is difficult to ensure sufficient uniformity of heating of the food 12 only by selecting the cooking menu. Therefore, the rotational speed of the drive motor 6 is reduced in advance as shown in menu A in FIG.
The heating characteristics are changed by changing the rotation speed of the drive motor 6 stepwise or by periodically changing the rotation speed of the drive motor 6 as shown in a menu C, thereby improving the uniformity of heating.

In this case, for example, in the heating and cooking of food such as sponge cake and meat loaf, a change in the state of the food due to heating is detected by using temperature detecting means, water vapor amount detecting means, weight detecting means, etc. as means for detecting the state of the food. Detects and changes the rotation speed of the turntable 13 when there is a state change, or calls a heating time known in advance by experiment from a menu already selected by the user, and changes the rotation speed of the turntable 13. The same effect can be obtained even if the control is performed to change.

FIG. 10 is a schematic diagram showing the relationship between the rotation speed of the drive motor and the heating time. In particular, for the food 12 requiring a long heating time, the same position is always irradiated with the same output electromagnetic wave during rotation while the rotation speed of the turntable 13 is kept constant. And the quality of heating may be reduced.

Therefore, as shown in FIG. 10, the food 12 is rotated on the turntable 13 at a specific rotation speed r1 for a certain time t1, and then the food 12 is rotated for a certain time t2.
Change the rotation speed to r2 different from that of turntable 13
Heat while rotating above.

By performing such heating, the food 12 requiring a relatively long cooking time is heated in combination with the heating characteristics, and can be uniformly heated due to the difference in heat conduction and heating characteristics. In this embodiment, the case where the rotation speed of the drive motor 6 is periodically changed by setting the rotation speed and the heating time of the drive motor 6 to two specific values has been described. However, the present invention is not limited to this. It is also possible to perform heating in a more complicated pattern.

FIG. 11 shows an example of the relationship between the drive motor and the heating time when the magnetron is operated intermittently. In the case of heating while reducing the heating output by intermittent operation in high-frequency heating, depending on the rotation speed, there is a possibility that the uniformity of heating may be significantly reduced due to synchronization at a place where local heating of food is likely to occur depending on the output ratio.

Therefore, as shown in FIG. 11, while the heating operation is being continued and the output of the magnetron 3 is OFF, the rotation of the turntable 13 is stopped to locally heat the food 12 at a specific position. Can be prevented. Also, in the actual intermittent operation, even if the output of the magnetron 3 is turned on, there is a time lag of about 2 seconds until the electromagnetic wave is guided into the inside of the heating chamber 2, so that the magnetron 3 is turned on for about 2 seconds after the output is turned on. The same effect can be obtained by rotating the table 13 with a delay.

Once the drive motor 6 is stopped, it is not known which direction the turntable 13 will rotate in the next operation. Therefore, by locking the rotation direction while the drive motor 6 is stopped, During the operation, the turntable 13 can be surely rotated in the same direction as before the stop. When the rotation cycle of the drive motor 6 is the same as the ON / OFF cycle of the output of the magnetron 6, it is apparent that the above-described locking in the rotation direction is not necessary.

FIG. 12 shows another example of the relationship between the drive motor and the heating time when the magnetron is operated intermittently. In the above embodiment, while the output of the magnetron 3 is stopped, the turntable 13 is also stopped in synchronism therewith. In this embodiment, while the output is stopped, the turntable 13 is stopped from a previously known stop time. The rotation speed is selected or calculated from the registered value and changed so that the position of the turntable 13 during the next operation matches the position of the turntable 13 when the output of the magnetron 3 is stopped. .

In this case, even when the heating is stopped, the food 12 is rotated, so that the air in the heating chamber 2 is agitated, so that heat conduction or radiation or radiation of heat from the food is performed. The heating characteristics may also change. In addition, the output is turned ON / O by the intermittent operation of the magnetron 3.
When the ratio of the FF period is 80% or more, even if the rotation speed of the drive motor 6 is changed when the output of the magnetron 3 is turned off, the operation period at the changed rotation speed is short, and the food 12 is turned on. 13 or jump out of the turntable 13. Therefore, it is preferable to set the ratio to, for example, 70% or less and change the rotation speed when the output of the magnetron 3 is turned off.

In actual intermittent operation, the magnetron 3
Even if the output of the magnetron 3 is turned on, there is a time lag of about 2 seconds until the high frequency is guided into the inside of the heating chamber 2, so that the turntable 13 is turned on for about 2 seconds after the output of the magnetron 3 is turned on.
The same effect can be obtained by changing the rotation speed of the lens and returning it to the original position. Further, as in the third embodiment described later, when the shape and the position of the food are specified, the turntable 13 is turned off while the output of the magnetron 3 is stopped.
It is expected that the same effect can be obtained by rotating by 180 °.

FIG. 13 is a diagram showing an example of a method for changing the rotation speed of the drive motor. Generally, a synchronous motor having a commercial frequency as a basic frequency is used as the drive motor 6 for rotating the turntable 13. Therefore, when the frequency supplied to the drive motor 6 before and after the change of the rotation speed is different from the commercial frequency, if the rotation speed is suddenly changed, the drive motor 6 may lock and stop rotating.

Therefore, as shown in FIG. 13, when changing the rotation speed of the drive motor 6, a time lag of Δt is provided, and during that period, the drive motor 6 is once driven at the commercial frequency and the rotation speed Y0 is changed. After that, the supply frequency is changed to increase the rotation speed to Y (FIG. 13A),
By lowering the rotation speed (see FIG. 13B), the rotation speed can be arbitrarily changed while the normal rotation of the turntable 13 is maintained.

The time lag Δt is equal to the turntable 13
The rotation speed of the drive motor 6 can be sufficiently normally changed by providing only about 2 seconds, for example, so long as the rotation cycle is not disturbed.

FIG. 14 is a diagram showing an example of a method for changing the rotation speed of the drive motor. Generally, a synchronous motor having a commercial frequency as a basic frequency is used as the drive motor 6 for rotating the turntable 13 of the microwave oven.
Therefore, when the frequency supplied to the drive motor 6 before and after the change of the rotation speed is different from the commercial frequency, if the rotation speed is suddenly changed, the drive motor 6 may lock and stop rotating. Further, if the rotation speed is suddenly changed, the food 12 placed on the turntable 13 may move, jump out of the turntable 13, or spill liquid such as a beverage from the container.

Therefore, as shown in FIG. 14, when the rotation speed of the drive motor 6 is changed from Y to Y ′ ″, a time lag of Δt is provided, and the time lag is gradually increased from the initial rotation speed Y at intervals of Δt. The rotation speed can be changed smoothly by changing the rotation speed to Y ′, Y ″, Y ″ ′. If the desired rotation speed to be changed is closer to the rotation speed at the commercial frequency than the rotation speed before the change, the drive motor 6 is turned off once.
By providing an interval of Δt and starting the drive motor 6 at the commercial frequency to gradually change the rotation speed,
The same effects as above can be obtained.

<Second Embodiment> A second embodiment of the present invention will be described with reference to the drawings. FIG. 15 shows an example in which the rotation speed of the drive motor during heating is changed depending on the heating state of the food. When the food 12A is selected by the operation panel 20, the rotation speed A of the drive motor 6 at the start of heating is set, and the food 1 is displayed on the turntable 13 rotated at the rotation speed A by operating the start button 23.
2A heating is started. After a lapse of time t 'from the start of heating, when the state detecting means (not shown) detects that the state of the food 12A has changed, the rotation speed of the drive motor 6 is changed to a rotation speed A' smaller than A. The food 1 on the turntable 13 rotated at the rotation speed A '.
2A heating is continued.

On the other hand, when the food 12B is selected by the operation panel 20, the rotation speed B of the drive motor 6 at the start of heating is set.
The heating of the food 12B is started on the turntable 13 rotated by. After a lapse of time t from the start of heating, the food 12
When the change in the state of B is detected by the state detecting means (not shown), the rotation speed of the drive motor 6 is changed to a rotation speed B 'higher than B, and the drive motor 6 is rotated at this rotation speed B'. Heating of the food 12B on the turntable 13 is continued.

For example, when popcorn is produced by heating grain corn, the turntable 13 is slower than usual at the start of heating.
Is rotated, and when the state detecting means detects that the grain cone has begun to pop, the rotation speed can be increased to uniformly and uniformly pop. Also, in the heating sequence that performs from thawing to heating such as cooking frozen pizza, from the start of heating to the end of thawing, it is driven at a predetermined rotation speed suitable for thawing, and by heating at a different rotation speed at the same time as the end of thawing, Excessive heating of the surface is prevented, and heat can be delivered to the inside of the food, so that the quality of heating is improved.

As the state detecting means for detecting the heating state of the food 12, for example, a change in the vibration of the turntable 13 on which the food 12 is being heated is detected, or a specific state associated with a change in the overheating state of the food 12 is detected. Means for detecting a sound (for example, popcorn popping sound) or detecting a temperature change (for example, a temperature change of the food at the time of changing from thawing to heating) due to a change in the overheating state of the food 12 and the like.

In particular, as a means for changing the rotation speed of the drive motor 6 according to a change in the temperature of the food 12, an infrared sensor, which is generally a non-contact type temperature detecting means, can be suitably used. This is to detect the intensity (amount) of infrared rays emitted from the food 12 being heated and convert it to the temperature of the food 12.

For example, as shown in FIG. 16, after the heating is started, the food 12 is heated by rotating the turntable 13 at a predetermined rotation speed Y0, and after a lapse of time t, the temperature of the food 12 is previously determined by an infrared sensor. Registered temperature T
Is reached as described above, the rotation speed of the turntable 13 is changed to Y1 larger than Y0. The heating further proceeds, and at time t ′, the temperature T ′ of the food 12 is increased.
When (T ′> T) is detected, the turntable 13 is set to Y
The food 12 on the turntable 13 is heated by rotating at Y2 larger than 1.

As a result, the food 1 is placed on the turntable 13 whose rotational speed varies according to the temperature of the food 12 being heated.
2 is heated. Therefore, the position of the portion where the electromagnetic wave applied to the food 12 is easily absorbed, that is, the position of the strongly heated portion of the food 12 is shifted by the rotation of the turntable 13, so that the uneven heating of the food 12 is prevented, and the uniform heating is achieved. The performance is improved.

<Third Embodiment> A third embodiment of the present invention will be described with reference to the drawings. FIG. 17 is a schematic sectional view of the microwave oven according to the present embodiment. 17, members common to those of the microwave oven according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 17, the microwave oven main body 1 outside the heating chamber 2 is provided with a horizontal position detecting means 15A on the upper surface and a vertical position detecting means 15B on the side surface, as shown in FIG. Food 1
2, the rough shape and its position are detected.

The usage of the microwave oven configured as described above will be described. Here, it is assumed that the type of food to be cooked and the cooking menu are classified in advance into liquids with a high water content, thawing, heating, and the like with as few categories as possible.

FIGS. 19 and 20 are top views showing the position of the food placed on the turntable. The user
In using the microwave oven, the user does not particularly care where the food 12 is placed on the turntable 13, and therefore, the food 12 is often placed at an arbitrary position on the turntable 13 at random.

In this case, when the food 12 has a relatively small shape (food A) as shown in FIG.
It is placed at various positions from near the center (FIG. 19A) on the turntable 13 to the periphery (FIG. 19B), while the food 12 has a relatively large shape as shown in FIG. In the case of food B), the position of the food on the turntable 13 is limited, and even if the food is placed near the periphery as shown in FIG.

When the food 12 is placed on the turntable 13 and the type or menu of the food 12 is selected from the operation panel 20, the turntable 13 is preliminarily rotated once, during which time the horizontal position detecting means 15A and the vertical position detection are performed. Means 1
The rough shape and the position of the food 12 are detected by 5B. Then, based on the result, the control unit 5 performs the operation shown in FIG.
A heating sequence as shown in FIG. 8 is set. And
When the start button 23 is pressed, heating is started according to the set heating sequence.

For example, when the food 12 is a potato and heating is performed at the position shown in FIG. 19A, the rotation speed of the drive motor 6 is changed at a constant cycle as shown in the food A and the position a in FIG. By doing so, the food 12 could be uniformly heated on the turntable 13 without unevenness.

On the other hand, when heating is performed at the position shown in FIG. 19B, the food 12 is small, and the rotation of the turntable 13 causes the food 1 to be spread over a wide area in the heating chamber 2.
2 can be rotated, so that the food 12 can be heated evenly and uniformly without rotating the drive motor 6 only at a certain rotation speed as shown in the food A and the position b in FIG.

On the other hand, when the food 12 is frozen minced meat and heating is performed at the position shown in FIG. 20A, the drive motor 6 is driven at a constant rotation speed as shown in the food B and the position a in FIG.
By simply rotating, there was no local heating and the unthawed portion was small.

On the other hand, when heating is performed at the position shown in FIG. 20B, the turntable 13 is driven at a constant rotation speed.
In the heating by the rotation of, a small amount of local heating occurred in the angular portion, and there were many unthawed portions as a whole, and the thawing performance was lower than that in the position of FIG. 20A regardless of the rotation speed. Therefore, by changing the rotation speed of the drive motor 6 during the thawing as in the food B and the position b in FIG. 18, the unthawed portion is reduced, and the thawing performance is greatly improved.

Therefore, by judging the size and position of the food 12 and appropriately controlling the rotation speed of the turntable 13, it is possible to ensure substantially uniform heating performance regardless of the place where the food 12 is placed. Can be. It is also possible to determine the type of heating operation after detecting the food shape and to prompt the user for a place suitable for heating based on the registered data.

<Fourth Embodiment> A fourth embodiment of the present invention will be described with reference to the drawings. FIG. 21 is a schematic enlarged view of the operation panel of the microwave oven according to the present embodiment. In this figure, members common to those of the microwave oven according to the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the microwave oven according to the present embodiment, when it is desired to rotate the turntable 13 at a rotation speed desired by the user, the user rotates the rotation operation section 21 of the operation panel 20 shown in FIG. The rotation speed of the table 13 (FIG. 1) can be set.

At this time, the rotation speed of the turntable 13 is displayed on the display unit 22 by numerical values and indicators, and the user operates the rotary operation unit 21 while checking the numerical values and the like. By doing so, it is possible to set an arbitrary rotation speed. In addition, various means can be considered such as changing the rotation speed using a button or a touch panel instead of the rotation operation unit 21.

FIG. 22 is a diagram showing an example of the relationship between the rotation speed of the rotation operation unit and the rotation speed of the drive motor set thereby. When the rotation speed of the turntable 13 is directly displayed on the display unit 22 as described above, as shown in FIG.
The actual rotation speed of the turntable 13 can be intuitively sensed, and fine adjustment of the rotation speed is possible.

In this case, since the rotation radius of the rotary operation unit 21 is considerably smaller than that of the turntable 13, the operation speed of the rotary operation unit 21 is reduced by lowering the rotation speed of the turntable 13 from the rotation speed of the rotary operation unit 21. The sense can be reflected on the setting of the rotation speed of the turntable 13. As a result, a sensible deviation between the rotation operation of the rotation operation unit 21 and the rotation speed of the turntable 13 set thereby is eliminated, and the desired rotation speed of the turntable 13 can be sensibly and promptly increased. Can be set.

In each of the above embodiments, the turntable 1
Although the case where the rotation of 3 is performed via the turntable support portion 14 to which the roller 19 is attached has been described, the same effect can be obtained even when the turntable 13 directly fixed to the shaft rotates directly. Needless to say. In addition, the microwave oven that introduces the electromagnetic wave generated by the magnetron 3 into the heating chamber 2 from the side has been described as an example, but the direction in which the electromagnetic wave is supplied may be upward, downward, or any other direction.

[0088]

As described above, according to the present invention, during the heating operation, the output of the magnetron and the rotation speed of the turntable are appropriately changed according to the type, shape or weight of the food or the state of the temperature of the food. Thus, an easy-to-use microwave oven capable of heating food on a turntable can be provided. Therefore, the food can be cooked evenly and uniformly irrespective of the type of the food and the like, so that the heating quality can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a microwave oven according to a first embodiment of the present invention.

FIG. 2 is a schematic enlarged view of an operation panel.

3A and 3B are diagrams illustrating an example of a finished state after cooking when a food placed on a turntable is heated, and FIG. 3A illustrates a state in which the rotation speed of a drive motor is rated at a normal commercial frequency. In the case of the rotation speed, (b) shows the case of the rotation speed corresponding to the type of food.

4A and 4B are diagrams illustrating an example of a finished state after cooking when frozen minced meat placed on a turntable is heated, and FIG. 4A is a diagram illustrating a state in which the rotation speed of a drive motor is a normal commercial frequency. (B)
Shows the case where the rotation speed is corresponding to the thawing according to the present invention.

FIG. 5 is a diagram illustrating an example of a relationship between a rotation speed of a drive motor and a heating time during heating depending on a type of food.

FIG. 6 is a diagram illustrating an example of a relationship between an output of an electromagnetic wave and a rotation speed of a drive motor at the time of heating depending on a type of food.

FIG. 7 is a diagram illustrating an example of a change in the rotation speed of a drive motor when food is heated.

FIG. 8 is a diagram illustrating an example of a relationship between a food heating time and a rotation speed of a drive motor during heating.

FIG. 9 is a diagram illustrating an example of a relationship between a drive motor, a rotation speed, and a cooking time for each cooking menu.

FIG. 10 is a diagram illustrating an example of a relationship between a rotation speed of a drive motor and a heating time.

FIG. 11 is a diagram illustrating an example of a relationship between a drive motor and a heating time when a magnetron is operated intermittently.

FIG. 12 is a diagram illustrating another example of the relationship between the drive motor and the heating time when the magnetron is operated intermittently.

FIG. 13 is a diagram illustrating an example of a method of changing a rotation speed of a drive motor.

FIG. 14 is a diagram showing another example of a method of changing the rotation speed of the drive motor.

FIG. 15 is a diagram relating to the operation control of the microwave oven according to the second embodiment of the present invention, showing an example in which the rotation speed of the drive motor is changed by changing the heating state of the food being heated. is there.

FIG. 16 is a diagram illustrating an example of a case where the rotation speed of a drive motor is changed according to a temperature change of a food item being heated.

FIG. 17 is a schematic sectional view of a microwave oven according to a third embodiment of the present invention.

FIG. 18 is a top view showing the position of a relatively small food placed on the turntable.

FIG. 19 is a top view showing a position of a relatively large food placed on the turntable.

FIG. 20 is a diagram illustrating an example of a relationship between a rotation speed and a heating time at the time of heating depending on a shape and a position of a food.

FIG. 21 is a schematic enlarged view of a display panel of a microwave oven according to a fourth embodiment of the present invention.

FIG. 22 is a diagram illustrating an example of a relationship between a rotation speed of a rotation operation unit and a rotation speed of a drive motor set thereby.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Microwave oven main body 2 Heating room 3 Magnetron 4 Waveguide 5 Control part 6 Drive motor 7 Weight detection part 8 Shaft 9 First gear 10 Second gear 11 Fan 12, 12A, 12B Foodstuff 13 Turntable 14 Turntable support 15A Horizontal position detecting means 15B Vertical position detecting means 19 Roller unit 20 Operation panel 21 Rotation operation unit 22 Display unit 23 Start button

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K086 AA01 CA01 CA04 CA20 CB03 CB04 CB05 CB06 CB15 CC04 CC06 CD08 3K090 LA07 MA01 3L086 AA01 BA10 BB06 BF07 CA02 CA04 CA16 CB05 CB20 CC06 DA12 DA29

Claims (13)

[Claims] 1. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotating shaft, and a rotary table for rotating the turntable via the rotating shaft. In a microwave oven having a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, the rotation speed of the drive motor is varied according to a mode selected from a plurality of modes registered in advance. A microwave oven provided with a control device for controlling. 2. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven provided with a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, the output of the electromagnetic wave generated from the magnetron in a mode selected from a plurality of modes registered in advance. A microwave oven, wherein the microwave oven is provided with a control device that is variably controlled according to an output of the electromagnetic wave. 3. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven having a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, a plurality of different rotation speeds of the motor depending on a mode selected from a plurality of modes registered in advance, The number of rotations or rotation time associated with each rotation speed is set, and during the heating operation, a specific rotation speed is sequentially selected from the plurality of rotation speeds, and the rotation corresponding to the rotation speed is selected. A microwave oven provided with a control device for controlling the drive of the drive motor until the number of times or the rotation time is reached. 4. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven having a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, the heating time is set according to a mode selected from a plurality of modes registered in advance. Yes,
A microwave oven comprising: a control device for selecting a drive time corresponding to the heating time from a plurality of drive motor rotation speeds associated with a plurality of predetermined time zones to drive and control the drive motor. 5. The method according to claim 1, wherein the plurality of modes include a type of the food,
The microwave oven according to any one of claims 1 to 4, wherein the microwave oven has at least one of a shape and a weight. 6. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven provided with a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, a state detection unit that detects a state of the heated food, and heating based on a detection result of the state detection unit. And a control device for variably controlling the rotation speed of the drive motor during operation. 7. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven equipped with a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, temperature detection means for detecting the temperature of the heated food, and heating based on the detection result of the temperature detection means And a control device for variably controlling the rotation speed of the drive motor during operation. 8. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotating shaft, and a rotary table for rotating the turntable via the rotating shaft. In a microwave oven provided with a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, a position detection unit that detects a position of the heated food, and heating is performed based on a detection result of the position detection unit. And a control device for variably controlling the rotation speed of the drive motor during operation. 9. The microwave oven according to claim 1, wherein the rotation speed of the drive motor is changed stepwise every time a predetermined time elapses. 10. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotating shaft, and a rotary table for rotating the turntable via the rotating shaft. In a microwave oven having a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, the output of the electromagnetic wave emitted from the magnetron is switched intermittently at a predetermined cycle. Yes,
A microwave oven provided with a control device for stopping the rotation of the drive motor or changing the rotation speed during a period when the output is not present. 11. The stop period of the output of the electromagnetic wave is changed by selecting or calculating the rotation speed of the turntable from a registered value from a stop time known in advance,
11. The microwave oven according to claim 10, wherein the position of the turntable when the next electromagnetic wave is output is matched with the position of the turntable when the output of the electromagnetic wave is stopped. 12. A heating chamber for accommodating food, a rotatable turntable on which the food is placed and supported by a rotary shaft, and a rotary table for rotating the turntable via the rotary shaft. In a microwave oven having a variable output drive motor and a magnetron that generates an electromagnetic wave for heating the food, the output of the electromagnetic wave emitted from the magnetron is switched intermittently at a predetermined cycle. Yes,
A microwave oven provided with a control device for changing a rotation speed of the drive motor during a period when the output is present. 13. A rotary operation unit for setting a rotation speed of the drive motor by a rotation operation, wherein a rotation speed of the rotation operation unit is set to correspond to a set rotation speed of the drive motor. Claims 1 to 12
The microwave oven according to any one of the above.