JP5028821B2 - Microwave heating device - Google Patents

Description

  The present invention relates to a heating apparatus that heats an object to be heated with microwaves.

  The microwave oven, which is a typical microwave heating device, can directly heat food, which is a typical object to be heated, using microwaves, so it can be heated quickly and heated for a short time. It has become.

  Moreover, the general heating output of a microwave oven for home use is called a high frequency output and is often 500 W or 600 W, but in recent years, there are some which have increased to 700 W or 1000 W in order to heat faster. When the heating output is 1000 W, the input is 1400 W or more, and there is no room for a general household commercial power supply (1500 W in the 100V15A system), so it is difficult to increase the input further to increase the output. However, even if the input power is the same, if the heating efficiency is increased, the output can be increased, and the heating speed can be further increased. Further, if the heating efficiency is increased, the input can be lowered for the same output, thereby saving energy. Recently, in addition to increasing the heating speed by improving the heating efficiency, an energy saving viewpoint of how much power consumption can be suppressed has become important. As a method for increasing the heating efficiency, it is conceivable to match the impedance on the microwave generating means side with the impedance on the load side. In the case of a microwave oven, a magnetron is used as a typical microwave generation means, and if the impedance on the magnetron side and the impedance on the load side match, microwaves can be efficiently transmitted to the load side, whereas the matching state If it deviates from, it becomes difficult to transmit the microwave to the load side, and the microwave that is not transmitted is reflected to the magnetron side and used as heat loss of the magnetron. Therefore, when the alignment state is good, the heating efficiency for heating the food by the microwaves efficiently transmitted into the heating chamber is high, and when the alignment state is bad, the heating efficiency is low. While the impedance on the magnetron side hardly changes, the impedance on the load side is large depending on the state of the food (amount, material, position, etc.) and the direction of the means for stirring the microwave, such as a rotating antenna or a stirrer. Change. In order to adjust the impedance on the load side, there is one that controls the position of a component called a matching element in the waveguide (see, for example, Patent Document 1).

  Moreover, although heating efficiency is not mentioned, in order to adjust the heating distribution of food, there is one that changes the heating distribution by controlling the direction of a rotating antenna arranged below the food to a predetermined direction. (For example, refer to Patent Document 2).

From the above, it can be easily considered that the impedance on the load side is adjusted by controlling the direction of the rotating antenna by using the fact that the impedance on the load side greatly changes depending on the direction of the rotating antenna.
JP-A-6-215871 JP 2003-17239 A

  However, when controlling the position of the matching element in the waveguide as in the conventional patent document 1, first, the amount of microwaves transmitted from the waveguide into the heating chamber is controlled, and the heating distribution is controlled. It does not change. Therefore, in order to make the heating distribution uniform, a means for stirring microwaves such as a rotating antenna and a stirrer, or a turntable for rotating food is separately required.

  Further, since the matching element moves in the waveguide, there is a possibility that a strong electric field is generated between the movable portion of the matching element and the wall surface of the waveguide. In order to prevent a spark as described in Patent Document 1, It may be necessary to control the magnetron output to a low output. In this case, even if the heating efficiency is increased, the heating speed becomes slow because of the low output, and the time required for heating cannot be shortened.

  Moreover, when controlling direction of the rotation antenna 1 arrange | positioned under the food like conventional patent document 2 like FIGS. 7-9, the boundary surface with the waveguide 3 in the center of the heating chamber 2 bottom face The rotary antenna 1 includes a coupling portion 5 that penetrates the coupling hole 4 and a radiation portion 6 that is integrated above the coupling portion 5. With this configuration, the extracted microwave is radiated outward from the coupling hole 4 side along the lower surface of the radiating unit 6 because it is between the coupling unit 5 and the coupling hole 4, and the rotating antenna 1 is centered on the coupling unit 5. It is intended to make it uniform in the direction of rotation by being driven to rotate.

  Therefore, even if the coupling portion 5 is in the center of the bottom surface of the heating chamber 2, microwaves are not emitted vertically above the coupling portion 5, but the radiating portion 6 is connected from the connection position of the coupling portion 5 and the radiating portion 6. It is emitted after being bent horizontally along the shape of Therefore, as shown in FIG. 8, when the food 7 having a large load is arranged vertically on the coupling portion 5, the microwave hits a portion outside the center of the food 7 instead of the center of the bottom as indicated by arrows a and b. It will be. Which part of the food 7 is directly applied to the microwave varies depending on the size of the food as well as the shape of the radiating portion 6, and particularly when the food is lightly loaded, the shape of the food is small. As indicated by the arrows c and d, there is a case where the microwave is not directly applied to the food 8.

  If the microwave directly hits the food 8, the food 8 efficiently absorbs the microwave, so that the heating efficiency is increased. However, when the microwave does not directly hit the food 8, the microwave is reflected by the heating chamber 2 wall surface many times as indicated by arrows c and d in FIG. The loss in heating increases, and the heating efficiency decreases. Therefore, in such a conventional configuration, even if the impedance on the load side is adjusted by controlling the direction of the rotating antenna 1, if the food is a light load, the loss on the wall surface increases, and the heating efficiency does not increase unexpectedly. Does not lead to heating speed up.

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide a microwave heating apparatus having high heating efficiency by directly applying microwaves when food is lightly loaded.

In order to solve the above-described conventional problems, a microwave heating apparatus of the present invention includes a microwave generating means, a waveguide for transmitting microwaves, a heating chamber connected to the upper portion of the waveguide, A placing table disposed in the heating chamber for placing a heated object, a heated object storage space formed above the mounting table in the heating chamber, and a lower position than the mounting table in the heating chamber. An antenna space, and a rotating antenna that spans the waveguide and the antenna space in order to radiate microwaves in the waveguide into the heating chamber, and the rotating antenna includes the waveguide and the heating chamber. A coupling portion that passes through a coupling hole provided in a boundary surface with the bottom surface and has a vertical direction that coincides with either the center of the mounting table or the center of the bottom surface of the heated object storage space, and above the coupling portion When integrated into And a radiation unit having a portion having a strong microwave radiation directivity, and a driving means for rotationally driving the rotating antenna around the coupling part, and controlling the driving means to control the direction of the rotating antenna Control means, and a setting means by which a user can set the magnitude of the heating output, and when the control means is set to the maximum output by the setting means, for lightweight load placed in a particular position indicated by a mark on the mounting table varies, when the radiation directivity is strong site microwaves of the rotating antennas stop toward the light load, the microwave The direction of the rotating antenna is controlled so that the impedance on the generating means side and the impedance on the load side are matched.

Thereby, when the object to be heated is a light load and is arranged at a specific position different from the vertical direction of the coupling part, the object to be heated is not on the vertical part of the coupling part. When the designed and stopped part of the rotating antenna with high radiation directivity of microwaves is stopped toward a light load, the extracted microwaves are between the coupling part and the coupling hole. It is possible to directly touch the object to be heated without being obstructed by the connecting portion. Furthermore, since the impedance on the microwave generating means side and the impedance on the load side are matched in the direction of this rotating antenna, direct application of the microwave to the object to be heated and impedance matching can both be achieved. The efficiency can be increased and the heating speed can be increased. In particular, when the user sets the maximum output using the setting means, the user often sets the maximum output because he wants to heat it quickly with a large output. Satisfaction of the person is increased. Moreover, since the heating time of a light load tends to be shorter than that of a large load from the beginning, the effect of shortening the time can be realized by further shortening the short time. In addition, because the size of the light load is smaller than that of the large load, even if it is exposed to the same microwave distribution, heating unevenness inside the food does not easily occur, and it is easy to average due to heat conduction in the food. Even if the rotation of is refrained, uneven heating is less likely to be noticed. As described above, it is possible to provide a microwave heating apparatus having a very high heating efficiency with a simple configuration, while suppressing the heating unevenness at a maximum output and a light load.

  According to the microwave heating apparatus of the present invention, when the object to be heated is a light load and is arranged at a specific position different from the vertical direction of the coupling part, the heated object is not located vertically on the coupling part. By appropriately selecting and designing the shape of the part and limiting the direction of the rotating antenna, the microwaves drawn because it is between the coupling part and the coupling hole can interfere with the coupling part or the connection part between the coupling part and the radiation part. Without being applied, it can be applied directly to the object to be heated. Furthermore, since the impedance on the microwave generating means side and the impedance on the load side are matched in the direction of this rotating antenna, direct application of the microwave to the object to be heated and impedance matching can both be achieved. The efficiency can be increased and the heating speed can be increased.

A microwave heating apparatus according to a first aspect of the present invention includes a microwave generating means, a waveguide for transmitting microwaves, a heating chamber connected to an upper portion of the waveguide, and the object to be heated for placing an object to be heated. A mounting table disposed in the heating chamber; a heated object storage space formed above the mounting table in the heating chamber; an antenna space formed below the mounting table in the heating chamber; and the waveguide. In order to radiate microwaves in the tube into the heating chamber, the antenna has a rotating antenna that extends over the waveguide and the antenna space, and the rotating antenna is provided at a boundary surface between the waveguide and the bottom surface of the heating chamber. And a coupling portion whose vertical direction coincides with either the center of the mounting table or the center of the bottom surface of the object-to-be-heated object storage space, and is integrated above the coupling portion. Wave radiation directivity A radiating unit having a large portion, a driving unit that rotationally drives the rotating antenna around the coupling unit, a control unit that controls the direction of the rotating antenna by controlling the driving unit, and a user Setting means capable of setting the magnitude of the heating output, and when the maximum output is set by the setting means, the control means is marked with a mark on the mounting table different from the vertical of the coupling portion. for lightweight load placed in a particular position shown, wherein when the site is strong radiation directivity of the microwaves of the rotating antennas were stopped toward the light load, the impedance and the load side of the microwave generation means side The direction of the rotating antenna is controlled so as to match the impedance.

Thereby, when the object to be heated is a light load and is arranged at a specific position different from the vertical direction of the coupling part, the object to be heated is not on the vertical part of the coupling part. When the designed and stopped part of the rotating antenna with high radiation directivity of microwaves is stopped toward a light load, the extracted microwaves are between the coupling part and the coupling hole. It is possible to directly touch the object to be heated without being obstructed by the connecting portion. Furthermore, since the impedance on the microwave generating means side and the impedance on the load side are matched in the direction of this rotating antenna, direct application of the microwave to the object to be heated and impedance matching can both be achieved. The efficiency can be increased and the heating speed can be increased. In particular, when the user sets the maximum output using the setting means, the user often sets the maximum output because he wants to heat it quickly with a large output. Satisfaction of the person is increased. Moreover, since the heating time of a light load tends to be shorter than that of a large load from the beginning, the effect of shortening the time can be realized by further shortening the short time. In addition, because the size of the light load is smaller than that of the large load, even if it is exposed to the same microwave distribution, heating unevenness inside the food does not easily occur, and it is easy to average due to heat conduction in the food. Even if the rotation of is refrained, uneven heating is less likely to be noticed. As described above, it is possible to provide a microwave heating apparatus having a very high heating efficiency with a simple configuration, while suppressing the heating unevenness at a maximum output and a light load.

  In addition, since the specific position is a position indicated by a mark on the mounting table, when the user places a light load, if there is a mark on the mounting table, there is a high possibility that the user will unintentionally try to put it on the mark. Since it is high, by setting this position as a specific position, it is possible to easily apply a microwave directly to an object to be heated with a light load.

The microwave heating apparatus according to the second invention, in particular, in the first invention, is configured such that the control means controls the reciprocating motion in the vicinity of a portion where the microwave radiation directivity of the rotating antenna is strong toward a specific position. Yes.

  As a result, during the reciprocating motion of the rotating antenna, it is possible to radiate the microwave strongly from the rotating antenna toward the specific position, and the microwave is directly applied to the object to be heated with a light load placed at the specific position. It can be applied and heated efficiently.

In the microwave heating apparatus according to the third aspect of the invention, particularly in the first aspect of the invention, the control means controls the rotational speed to be slow in the vicinity of the portion where the microwave radiation directivity of the rotating antenna is strong toward the specific position. It is configured.

This can increase the proportion of time that the rotating antenna is facing a specific position compared to constant rotation, so it can increase the proportion of time that microwaves are strongly emitted from the rotating antenna toward the specific position, It is possible to increase the proportion of the time for efficiently applying the microwave directly to the object to be heated of a light load arranged at a specific position.

The microwave heating apparatus according to a fourth aspect of the present invention is the first aspect of the present invention, in particular, the control means is arranged such that the impedance on the microwave generation means side with respect to the light-weight load placed at a specific position until a predetermined time after the start of heating. The direction of the rotating antenna is controlled so that the impedance on the load side is matched.

  Thus, until a predetermined time after the start of heating, the microwave can be directly applied to the object to be heated having a light load disposed at the specific position, and the object can be efficiently heated.

The microwave heating apparatus of the fifth invention has temperature detection means for detecting the temperature of the object to be heated, particularly in the first invention, and the control means until the object to be heated reaches a predetermined temperature, The direction of the rotating antenna is controlled so that the impedance on the microwave generating means side and the impedance on the load side are matched with respect to the lightweight load arranged at a specific position.

  Accordingly, until the object to be heated reaches a predetermined temperature, the microwave can be directly applied to the object to be heated with a light load arranged at the specific position, and the object can be efficiently heated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

( Reference Example 1 )
1 and 2 are configuration diagrams of a microwave oven as a typical microwave heating apparatus as a reference example according to the present invention. FIG. 1 is a cross-sectional view seen from above, and FIG. 2 is a cross-sectional view seen from the front. is there.

  A magnetron 9 which is a typical microwave generation means, a waveguide 10 which transmits microwaves, a heating chamber 11 connected to the upper part of the waveguide 10, and a food 12 which is a typical object to be heated A mounting table 13 disposed in the heating chamber 11 for mounting, the inside of the heating chamber 11 is divided into upper and lower parts by the mounting table 13, and a heated object storage space 14 formed on the upper side, and formed on the lower side. In order to radiate the microwave in the waveguide 10 into the heating chamber 11, the antenna space 15 includes a rotating antenna 16 that extends over the waveguide 10 and the antenna space 15. And a coupling portion 18 penetrating through a coupling hole 17 provided on the bottom surface of the heating chamber 11 and a radiation portion 19 integrated above the coupling portion 18, and the rotary antenna 16 is driven to rotate around the coupling portion 18. This is a typical drive means A motor 20, and a control means 21 for controlling the orientation of the rotating antennas 16 by controlling the motor 20, and setting means 22 the user can set the size of the heating output.

  The coupling portion 18 and the radiating portion 19 of the rotating antenna 16 are both made of metal, and the radiating portion 19 is bent by bending portions 23 and 24 that are bent across the coupling portion 18 and the other side is bent. Since the gap between the bent portion 23, 24, 25 and the bottom surface of the heating chamber 11 is narrowed by the bent portions 23, 24, 25, it is difficult for microwaves to propagate in the bent portions 23, 24, 25 direction. , 24 and 25, microwaves are mainly transmitted in the direction of the open portion 26.

This is as if the upper surface of the radiating portion 19 and the bottom surface of the heating chamber 11 form an H surface, the vertical surfaces of the bent portions 23 and 24 form an E surface, and the vertical surface of the bent portion 25 ends. It seems to behave like a wave tube. Therefore, the microwave is radiated from the open part 26. In this embodiment, as is apparent from FIG. 1, the coupling portion 18 is disposed at a position shifted to the right from the center of the heating chamber 11, and the opening portion 26 of the rotating antenna 16 is stopped to the left. Thus, the microwave radiated from the opening portion 26 can be directed to the center of the mounting table 13 (a specific position different from the vertical position of the coupling portion 18).

  In this state, when a light load such as 200 g of milk full of a cup is disposed as the food 12 in the center of the mounting table 13, the microwave can be directly applied in the direction of the arrow e in FIG.

  Further, when a lightweight load is arranged at the center of the mounting table 13 and the rotating antenna 16 is stopped in the direction of FIG. 1, the impedance on the magnetron 9 side and the impedance on the load side are matched. Most foods heated in a microwave oven have a light load of 300 g or less. For example, if the impedance is matched with 200 g of milk in a cup, most foods can be efficiently heated. Incidentally, the current microwave oven is designed to determine the high frequency output from the temperature rise when warming 2 kg of water, and is designed to match 2 kg of water. Thus, current microwave ovens tend to be inefficient because they cannot match the light load. In other words, the present embodiment has an effect of increasing the heating speed with high efficiency in a light load that is often used in practice.

  In addition, when the user sets a maximum output that can be set by the setting unit 22, the control unit 21 controls the direction of the rotating antenna 16 to the direction shown in FIG. For example, when the output can be selected from 300 W, 500 W, and 1000 W, it is when 1000 W is set. Setting the maximum output by the user means that the user wants to heat quickly and quickly, rather than heating it well with low output, so it can be heated quickly to match the user's needs. . On the other hand, when the user is set to 300 W, it is understood that he wants to improve the performance rather than the speed, so it is desirable to control the rotating antenna 16 to be uniform without stopping it. Here, in order to rotate the rotating antenna 16 or stop in a predetermined direction, although not shown, a cam that is fitted with the motor 20 or a switch that is pushed in the middle of rotation by the cam is configured, for example, the moment when the switch is pushed. Since it corresponds to a predetermined direction, there is a method of stopping there. Of course, a stepping motor is generally used as the motor.

  The control means 21 is configured to control the rotating antenna 16 to stop until a predetermined time after the start of heating. For example, if the output is 1000 W, it is 2 minutes. When milk is taken out of the refrigerator and 200 cc is poured into a cup and heated in a microwave oven, it becomes sufficiently hot when heated at 1000 W for 2 minutes. When heating a light load, the heating time may be short, and if the rotating antenna 16 is kept stopped, there is a risk of uneven heating when there is a large load. From a certain amount of time), it is desired to rotate and make uniform for a large load.

  Of course, since the user may set the heating time, it is conceivable to control the direction of the rotating antenna 16 according to the set time.

  Furthermore, although the expression that the rotating antenna 16 is stopped is used, even if it is rotating only at the beginning or moving only for a moment in the middle, the object of the present invention is to some extent if it is stopped during most of the heating. Therefore, it is determined that such a configuration is also included in the present invention.

Or, more present embodiment 1, if the food 12 is placed in different specific position (center of the mounting table 13) and the upper vertical and coupling portion 18 lighter load, food 12 is on the vertical of the coupling portion 18 Since the shape of the radiating portion 19 is appropriately selected and designed as shown in FIG. 1 and the direction of the rotating antenna 16 is limited, the microwave extracted between the coupling portion 18 and the coupling hole 17 is It can be directly applied to the food 12 without being obstructed by the connecting portion 18 or the connecting portion between the connecting portion 18 and the radiating portion 19. Furthermore, since the impedance on the magnetron 9 side and the impedance on the load side are matched in the direction of the rotating antenna 16, it is possible to achieve both the direct application of the microwave to the food 12 and the impedance matching, thereby improving the heating efficiency. Can increase the speed of heating.

  In particular, when the user sets the maximum output by the setting means 22, there are many cases where the user wants to heat quickly with a large output, and at this time, the heating is actually speeded up to shorten the time. User satisfaction increases. Moreover, since the heating time of a light load tends to be shorter than that of a large load from the beginning, the effect of shortening the time can be realized by further shortening the short time. In addition, because the size of the light load is smaller than that of the large load, even if it is exposed to the same microwave distribution, heating unevenness inside the food does not easily occur, and it is easy to average due to heat conduction in the food. Even if the rotation of 16 is refrained, uneven heating is less likely to be noticed.

  As described above, it is possible to provide a microwave heating apparatus having a very high heating efficiency with a simple configuration, while suppressing the heating unevenness at a maximum output and a light load.

  In addition, since the specific position is configured in the center of the mounting table 13, when the user places a light load, the user unconsciously tries to place it in the middle. Therefore, the microwave can be easily set by setting this position as the specific position. Can be applied directly to the lightly loaded food 12.

  In addition, the control means 21 is configured to control the rotating antenna 16 so as to stop the portion (opening portion 26) where the microwave radiation directivity is strong toward a specific position (the center of the mounting table 13). As a result, while the rotating antenna 16 is stopped, microwaves can be strongly emitted from the rotating antenna 16 toward the specific position (the center of the mounting table 13), and the microwave is disposed at the specific position (the center of the mounting table 13). Microwaves can be applied directly to the light-weight food 12 that has been lightly loaded to efficiently heat the food.

  Further, the control means 21 determines the impedance on the magnetron 9 side with respect to a light load (for example, milk 200 g) disposed at a specific position (for example, 200 g of milk) until a predetermined time (for example, 2 minutes) after the start of heating. The direction of the rotating antenna is controlled so that the impedance on the load side is matched. Thereby, until a predetermined time (for example, 2 minutes) after the start of heating, microwaves are directly applied to a light load to be heated (for example, 200 g of milk) arranged at a specific position (the center of the mounting table 13). Can be heated.

( Reference Example 2 )
3 and 4 are configuration diagrams of the microwave oven, FIG. 3 is a sectional view seen from above, and FIG. 4 is a sectional view seen from the right.

A description will be given centering on differences from Reference Example 1 . Since the lower part of the heating chamber 27 is narrowed and made smaller, the mounting table 28 is arranged in front of the heating chamber 27. For this reason, the center of the mounting table 28 does not coincide with the center of the bottom surface of the heated object storage space 29. However, in this case, a circle 30 is drawn as a mark on the mounting table 28 at a position coinciding with the center of the bottom surface of the heated object storage space 29, and the user places food in the center of the circle 30. The rotating antenna 31 has a configuration in which the radiating portion 32 has a flat plate shape and has a punched hole 33, and transmits microwaves mainly in the direction of the punched hole 33. In this reference example , as is apparent from FIG. 3, the coupling portion 34 is disposed at a position shifted forward from the center of the heated object storage space 29, and the punched hole 33 of the rotating antenna 31 is directed rearward. Thus, the microwave radiated from the punched hole 33 can be directed to the center of the bottom surface of the object-to-be-heated storage space 29 (a specific position different from the vertical position of the coupling portion 34).

  In this state, when a light load such as 150 g of rice bowl full of rice is placed as the food 12 in the center of the mounting table 28, microwaves can be directly applied in the direction of the arrow f in FIG.

  Further, when the light load is arranged at the center of the bottom surface of the heated object storage space 29 and the punching hole 33 is facing backward, the impedance on the magnetron 9 side and the impedance on the load side are matched.

  In addition, when the user sets the maximum output that can be set by the setting unit 22, the control unit 21 reciprocates the rotation antenna 31 at a narrow angle with the punched hole 33 as the center. Compared to when the rotating antenna 31 is completely stopped, it can be expected to achieve uniform heating while maintaining high heating efficiency by reciprocating slightly.

  Further, it has temperature detecting means 35 for detecting the temperature of the food, and the control means 36 reciprocates the rotating antenna 31 at a narrow angle centering on the rearward direction until the food reaches a predetermined temperature. It is configured to exercise. For example, the maximum temperature of food reaches 70 ° C. If the maximum temperature is 70 ° C, most of the heating is considered complete, but in the unlikely event that the minimum temperature is too low, it may be unsatisfactory in the future. It is conceivable that the rotation antenna 31 can be made uniform by changing the direction of the rotating antenna 31.

  Alternatively, the temperature unevenness is determined by detecting the temperature at a plurality of locations in the food. For example, if the difference between the minimum temperature and the maximum temperature exceeds a threshold value, the direction of the rotating antenna 31 can be changed to heat the temperature unevenness. Conceivable. In this case, there is an effect that heating can be performed quickly if temperature unevenness does not occur, and uniform heating can be performed by changing the heating distribution so as to compensate for temperature unevenness.

As described above, according to this reference example , when the food is a light load and is arranged at a specific position (center of the bottom surface of the heated object storage space 29) that is different from the vertical on the coupling portion 34, the food is on the vertical of the coupling portion 34. Since the shape of the radiating portion 32 is appropriately selected and designed as shown in FIG. 3 and the direction of the rotating antenna 31 is limited, the microwave extracted between the coupling portion 34 and the coupling hole 17 can be obtained as follows. It is possible to directly hit the food without being obstructed by the coupling portion 34 or the connecting portion of the coupling portion 34 and the radiation portion 32.

  Furthermore, since the impedance on the magnetron 9 side and the impedance on the load side are matched in the direction of the rotating antenna 31, it is possible to achieve both the direct application of microwaves to food and the impedance matching, thereby increasing the heating efficiency. Can speed up the heating.

  Further, the specific position is configured at the center of the bottom surface of the heated object storage space 29. As a result, when the user places a light load, the user unconsciously tries to place it in the middle, but the middle is that the mounting table 28 is compared with the bottom surface of the heated object storage space 29 as in the present embodiment. If there is a difference in size, there is a possibility that the center of the bottom surface of the heated object storage space 29 may be reached. Can be hit.

Further, the control means 21 controls the reciprocating motion of the rotating antenna 31 in the vicinity where the microwave radiation directivity portion (the hole 33) faces the specific position (the bottom center of the heated object storage space 29). It is configured. As a result, during the reciprocating motion of the rotating antenna 31, microwaves can be radiated strongly from the rotating antenna 31 toward the specific position (the center of the bottom surface of the heated object storage space 29). Microwaves can be directly applied to the lightly loaded food (for example, 150 g of rice) disposed in the bottom center of the heated object storage space 29 for efficient heating.

  Moreover, it has the temperature detection means 35 which detects the temperature of a foodstuff, and the control means 21 is the light weight arrange | positioned in the specific position (bottom surface center of the to-be-heated object accommodation space 29) until a foodstuff reaches predetermined | prescribed temperature. The direction of the rotating antenna 31 is controlled so that the impedance on the magnetron 9 side and the impedance on the load side are matched with the food (for example, 150 g of rice) of the load. Thus, until the food reaches a predetermined temperature, the microwave is directly applied to the lightly loaded food (for example, 150 g of rice) placed at a specific position (center of the bottom surface of the heated object storage space 29). Can be heated.

( Embodiment 1 )
5 and 6 are configuration diagrams of the microwave oven, FIG. 5 is a cross-sectional view seen from above, and FIG. 6 is a cross-sectional view seen from the right.

The description will focus on the differences from Reference Example 1 and Reference Example 2 . The vertical direction of the coupling portion 38 of the rotating antenna 37 is configured to coincide with the center of the mounting table 39 and the center of the bottom surface of the heated object storage space 40. Instead, the specific position where the lightweight load is placed is behind the center of the mounting table 39, and an ellipse 41 is drawn as a mark. Further, the radiating portion 42 of the rotating antenna 37 has a notch 43 in a flat plate. When the notch 43 is turned rearward as shown in FIG. 5, a light load placed on an ellipse 41 as shown by an arrow g in FIG. The positional relationship is such that microwaves are emitted toward the bottom of the food 12.

  Further, when the light load is arranged on the ellipse 41 and the rotating antenna 37 is stopped in the direction of FIG. 5, the impedance on the magnetron 9 side and the impedance on the load side are matched.

  Further, the control means 21 is assumed to change the rotation speed of the rotating antenna 16 when the maximum output that can be set by the user by the setting means 22 is set, so that the rotation speed becomes slow in the vicinity of the direction of FIG. It is configured to control. Compared to when the rotating antenna 37 is completely stopped, other directions are also generated, so that uniform heating can be expected while maintaining high heating efficiency.

  As described above, according to the present embodiment, when the food is a light load and is arranged at a specific position (ellipse 41) different from the vertical position of the coupling portion 38, the food is not on the vertical position of the coupling portion 38. Thus, by appropriately selecting and designing the shape of the radiating portion 42 and limiting the direction of the rotating antenna 37, the microwave extracted between the coupling portion 38 and the coupling hole 17 can be coupled to the coupling portion 38 or the coupling portion. It can be applied directly to the food without being obstructed by the connecting portion between the portion 38 and the radiating portion 42. Furthermore, since the impedance on the magnetron 9 side and the impedance on the load side are matched in the direction of the rotating antenna 37, it is possible to achieve both the direct application of the microwave to the food and the impedance matching, thereby increasing the heating efficiency. Can speed up the heating.

  Further, the specific position is configured in advance at a position (ellipse 41) indicated by a mark on the mounting table. As a result, when a user places a light load, if there is a mark on the mounting table, there is a high possibility that the user will unintentionally place the mark on the mounting table. Can be directly applied to an object to be heated with a light load.

  In addition, the control means is configured to control the rotation speed to be slow in the vicinity where the portion (cut 43) having a strong microwave radiation directivity of the rotating antenna faces the specific position (ellipse 41). As a result, it is possible to increase the proportion of the time during which the rotating antenna faces the specific position (ellipse 41) as compared with the constant rotation, and thus strongly radiate microwaves from the rotating antenna 37 toward the specific position (ellipse 41). The ratio of time can be increased, and the ratio of the time for efficiently applying microwaves directly to the food with a light load placed at the specific position (ellipse 41) can be increased.

  Although three embodiments have been described above, the shape of the rotating antenna is not limited to the configuration shown in the embodiments. It is also possible to combine them with each other. The idea is that the vertical direction of the coupling part is generally different from the specific position where the load is placed, and the rotating antenna performs a different operation from the other output settings at the maximum output that can be set, and a light load (for example, 200 g of milk full of a cup) ) May be used as long as the heating speed is increased when the microwave is directly applied when heated at a specific position, rather than when heated at the coupling portion.

  As described above, according to the present invention, since microwaves from a rotating antenna can be used to efficiently heat and match a lightweight load disposed at a specific position, as a cooking utensil using microwaves Microwave ovens, microwave ovens, heating and thawing devices for various dielectric materials, semiconductor devices using microwaves, heating devices in industrial fields such as drying devices, ceramic heating, sintering or biochemical reactions Applicable to.

The cross-sectional block diagram which looked at the microwave heating apparatus of the reference example 1 of this invention from the top Cross-sectional configuration diagram of the microwave heating device viewed from the front The cross-sectional block diagram which looked at the microwave heating apparatus of the reference example 2 of this invention from the top Cross-sectional configuration diagram of the microwave heating device viewed from the right 1 is a cross-sectional configuration diagram of a microwave heating apparatus according to a first embodiment of the present invention as viewed from above. Cross-sectional configuration diagram of the microwave heating device viewed from the right Cross-sectional configuration diagram of a conventional microwave heating device viewed from above Cross-sectional configuration diagram of the microwave heating device viewed from the right Cross-sectional configuration diagram of the microwave heating device viewed from the right

9 Magnetron (microwave generation means)
10 Waveguide 11, 27 Heating chamber 12 Food (object to be heated)
13, 28, 39 Mounting table 14, 29, 40 Heated object storage space 15 Antenna space 16, 31, 37 Rotating antenna 17 Coupling hole 18, 34, 38 Coupling unit 19, 32, 42 Radiation unit 20 Motor (driving means)
21, 36 Control means 22 Setting means 30 yen (mark)
35 Temperature detection means 41 Ellipse (mark)

Claims (5)

Microwave generation means;
A waveguide for transmitting microwaves;
A heating chamber connected to the top of the waveguide;
A mounting table disposed in the heating chamber for mounting an object to be heated;
A heated object storage space formed above the mounting table in the heating chamber;
An antenna space formed below the mounting table in the heating chamber;
A rotating antenna that spans the waveguide and the antenna space to radiate microwaves in the waveguide into the heating chamber;
The rotating antenna passes through a coupling hole provided in a boundary surface between the waveguide and the heating chamber bottom surface, and is perpendicular to either the center of the mounting table or the center of the bottom surface of the heated object storage space. A coupling portion having the same direction, and a radiation portion integrated with the coupling portion and having a portion having a strong microwave radiation directivity;
Driving means for rotationally driving the rotating antenna around the coupling portion;
Control means for controlling the direction of the rotating antenna by controlling the driving means;
Having a setting means by which the user can set the magnitude of the heating output,
Wherein, when setting the maximum output by the setting means, for the light-weight load placed in a particular position with vertical upper represented by different indicia on the mounting table of the coupling portion, wherein Controlling the direction of the rotating antenna so that the impedance on the microwave generating means side and the impedance on the load side are matched when a portion of the rotating antenna with a strong radiation directivity of microwaves is stopped toward the lightweight load Microwave heating device configured. 2. The microwave heating apparatus according to claim 1, wherein the control means is configured to control the reciprocating motion of a portion of the rotating antenna having a strong microwave radiation directivity in the vicinity of a specific position. 2. The microwave heating apparatus according to claim 1, wherein the control means is configured to control the rotation speed to be slow in the vicinity of a portion where the microwave radiation directivity of the rotating antenna is strong toward a specific position. The control means is configured to control the direction of the rotating antenna so that the impedance on the microwave generating means side and the impedance on the load side are matched with respect to the lightweight load disposed at a specific position until a predetermined time after the start of heating. The microwave heating apparatus according to claim 1. It has a temperature detecting means for detecting the temperature of the object to be heated, and the control means has an impedance on the microwave generating means side with respect to the light load placed at a specific position until the object to be heated reaches a predetermined temperature. The microwave heating apparatus according to claim 1, wherein the direction of the rotating antenna is controlled so that the impedance on the load side is matched with the load.

Images