JPH10110955A - Microwave heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cope with uneven heating pattern generated when a foodstuff is heated and cooked by a microwave heating device. SOLUTION: There are provided inside and outside a heating chamber 1, means for generating atomized water from either water or alkaline ion water, an atomizing amount adjusting means, atomized water temperature control means, a non-contact temperature sensor for sensing a temperature state of a heated foodstuff F, a turn-table rotary position sensing means for taking an orientation of the foodstuff placed on the turn-table 2, and means for sucking residual water droplets at the extremity end of a nozzle in a spot atomizing device 4 and the like. A temperature of the heated foodstuff F is detected under a state in which the heated foodstuff F is heated to a certain degree with a micro-wave, an appropriate infection amount of atomized water is calculated in reference to information about sensing of a heating degree or a position of a low temperature part caused by irregular heating and sensing of a degree of low temperature or the like, the atomized water is atomized in a spot-like manner against the low temperature part of irregular heating, and a portion of the foodstuff to which atomized water having a higher lost coefficient of induction member than that of the foodstuff is applied is more rapidly heated than that of other portions with a subsequent microwave heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave heating device represented by a microwave oven, and more particularly to a microwave heating device having a function of spraying atomized water onto a food to be heated in order to reduce uneven heating of the food to be heated. The present invention relates to a wave heating device.

[0002]

2. Description of the Related Art In the case of heating and cooking by irradiating microwaves to a food to be heated using a microwave oven of this kind, the conventional method of heating the food to be heated is not uniform, that is, the so-called uneven heating is almost impossible. However, it is known that the unevenness of the heating generated when performing the microwave heating mainly includes the following three types of factors. That is, (1) a microwave oven emits microwaves generated by a magnetron into a heating chamber via a waveguide so as to irradiate microwaves to a heated food material accommodated in the heating chamber. Although the heating chamber is formed, the heating chamber is generally formed in a rectangular parallelepiped shape, and since the food to be heated is placed at the center of the heating chamber, the heating chamber is placed at a position deviated to one corner of the heating chamber. It is difficult to irradiate microwaves evenly to the food to be heated from the tube, and (2) the food to be heated is in a wide variety of forms. Thin ingredients, tall ingredients,
Some foods have shapes that are difficult to irradiate microwaves evenly, such as foods with some depressions, and (3)
It is conceivable that the dielectric loss coefficient specific to the food material is partially different in most of the food materials to be heated.

[0003] Regarding the factors mentioned in the above (1), conventionally, the inner wall of the microwave oven, that is, the wall shape of the heating chamber has been devised, so that the heating target placed at the center of the heating chamber has basically been devised. Although the food is designed to irradiate the microwaves evenly, it is difficult to obtain a completely uniform irradiation in all directions from the perspective of the food with a microwave oven with a rectangular parallelepiped inner wall. is there.

[0004] Regarding the factors mentioned in (2), in the case of foodstuffs having an elongated projection shape, microwaves are often concentrated as antennas due to their sharp shapes, and other foodstuffs are used. Is more likely to be in an overheated state. Also, assuming that the food is placed in the center area of the heating chamber as described above, the food is designed to be irradiated with microwaves as evenly as possible. In the ingredients that reach the shape,
It is difficult to irradiate microwaves on the same level as the food portion located near the center of the floor of the heating room.

Regarding the factors mentioned in (3), the dielectric loss coefficient of water at room temperature is the largest, but varies greatly depending on the type of food. Therefore, for example, in the case of cattle or pork meat mass, when the lean part and the fat part are significantly separated, the dielectric loss coefficient is greatly different in both parts, and microwaves are equally generated. Even if it is irradiated, a difference occurs in the heating temperature. Further, when many kinds of foodstuffs are mixed in a single container such as a lunch box, even if each foodstuff is irradiated with the same amount of microwaves, the finished temperature at the time of completion of cooking is different.

Conventionally, the following various countermeasures have been taken for such factors. In other words, it is formed into a shape with a slight uneven surface on the wall surface of the heating chamber and delicately adjusts the microwave reflection direction.A rotating disk called a stirrer plate is installed at the microwave outlet of the waveguide, Microwave irradiation direction is gradually changed. Heating is performed by forming projections called stubs partially on the top plate or the side wall of the heating chamber, and placing the non-heating food on the microwave irradiation direction. One that intentionally distorts the room in the room, one that gradually changes the microwave irradiation direction by configuring the stub to be movable linearly or rotationally, and one that specializes the microwave exit opening of the waveguide. By changing the radiation direction of the microwave at the microwave outlet by forming it into a shape, a turntable for placing non-heated food is provided on the bottom of the heating chamber, and microwave irradiation Even if there is no uniformity, the food itself is rotated to prevent uneven heating by rotating the turntable, and the non-heated food is three-dimensional as it moves not only in rotation but also in the vertical direction. Irradiation mode such as changing the irradiation intensity of microwaves with the passage of time or providing an irradiation pause period, and using non-heating time periods with low irradiation intensity or pause periods By taking measures such as reducing the temperature difference between the parts that were strongly heated and the parts that were weakly heated by the heat conduction in the food, etc., we were able to reduce the uneven heating caused by microwave irradiation. I was planning.

[0007]

However, the above-mentioned configurations for reducing the occurrence of uneven heating of non-heated foodstuffs have the following problems. However, when any foodstuff is actually heated by microwave irradiation, At present, however, it is not possible to take measures according to the heating condition of foods.

In other words, the above-mentioned countermeasures for uneven heating are to add a mechanical structure for suppressing uneven heating, wherein the food material to be heated is placed at the center of the heating chamber, and any part of the food material is not used. If the conditions required for unheated foods are ideally set, such as a uniform dielectric loss coefficient and an ideal dome shape, uneven heating is minimized. It is possible to However, in fact, it goes without saying that it is not a satisfactory recommendation for uneven heating because, of course, non-heated foodstuffs have various shapes, and the dielectric loss coefficient may be partially different. Met.

In addition, since the measures against uneven heating described in (1) above impart exercise to non-heated foods or add strength to microwaves, even if any non-heated foods are targeted, It can be said that the effect of reducing the uneven heating is more excellent than the countermeasure of the above. However, in recent high-power microwave ovens, the cooking time has been significantly reduced as compared with the conventional microwave ovens, and the rotation speed of the turntable has not yet been sufficient. Cooking is completed. For this reason, the uneven irradiation of the microwave has a large effect on the heating of the non-heated food, and there is a great possibility that the cooking will be completed before the amount of heat can be evenly dispersed by heat conduction in the food.

In view of the above, unlike the above-described heating method using microwaves and the constitution of the heating chamber, the uneven heating is reduced by attaching atomized water to the non-heating food. The thing is, for example,
Japanese Patent Application Laid-open No. 206798/1990 discloses a “high-frequency heating device” and Japanese Utility Model Application Laid-Open No. 1-9802 discloses a “microwave heating cooker”.

[0011] In the apparatus provided with the means for applying the atomized water to the non-heated food, the atomized water generated outside the microwave oven is placed on the airflow generated by a fan provided in the heating chamber and heated. Atomizing water is attached to the whole food by blowing it out into the room. According to this configuration, there is an advantage that the non-heated food can be humidified, and partial overheating of the food can be suppressed.

However, in the case of a mixed food in which a variety of food materials are mixed and the dielectric loss coefficients are variously different in individual portions of the food material, one portion of the food material is unchanged without any change. Irradiation with microwaves at this condition will cause considerable heating unevenness. Further, there is also a problem that the heating unevenness under such conditions cannot be expected at all unless the heating is actually performed to some extent, that is, the state of the heating unevenness cannot be known unless cooking is performed.

The applicant of the present invention discloses a means for adjusting the humidity of the heating chamber by adsorbing with an adsorbent such as silica gel in "Cooking Apparatus with Temper Apparatus and Temper Method" in Japanese Patent Application No. 8-017385. It discloses a technical means of regenerating water by heating with a heater and discharging the water to a heating chamber. However, although it is possible to arbitrarily control the humidity environment of the heating chamber by this means, it is not possible to reduce uneven heating of the food F by this.

[0014]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has a heating chamber for accommodating a food to be heated, and a heating chamber for heating the food to be heated. A configuration including microwave generating means for introducing microwaves, and spot spraying means for spraying atomized water toward a partial region of the food to be heated when microwaves are introduced into the heating chamber by the microwave generating means. During microwave heating, atomizing water that maximizes the dielectric loss coefficient is sprayed on a part of the food to be heated, thereby increasing the efficiency of microwave absorption in the sprayed area and active heating unevenness. This is to correct the problem.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments in which the present invention is applied to a microwave oven will be described in detail with reference to the drawings. FIG. 1 shows an outline of a basic configuration of a microwave oven according to the present embodiment. In the microwave oven shown in this figure, a turntable 2 is provided at a central portion on a bottom plate 1a of a rectangular parallelepiped heating chamber 1 provided in an outer shell of a not-shown microwave oven main body. The waveguide opening 3 of the microwave generating means faces the ceiling plate of the heating chamber 1 not shown. The microwave generating means includes a magnetron and a waveguide (both not shown) provided outside the heating chamber 1, and the microwave generated by the magnetron passes through the waveguide from the opening 3. It is led into the heating chamber 1.

The microwave introduced into the heating chamber 1 is repeatedly reflected by the side wall 1b of the heating chamber 1, the turntable 2, and the food F to be heated, as indicated by a rough broken line a in FIG. The food F on the turntable 2 is heated by the standing wave generated by superimposing the microwave radiated from the waveguide opening 3.

A spot sprayer 4 is provided on the side wall 1b of the heating chamber 1.
Of the nozzle 4a (see FIG. 7). The spray port 5 may be installed on the ceiling plate other than the side wall 1 b of the heating chamber 1, and the installation site may be any one or more of the side wall 1 b or the ceiling plate. The nozzle 4a for determining the spray direction is attached at an angle aimed at a partial area of the food F to be heated.
W indicates an atomized water spray path which is sprayed from the spray port 5 toward a partial region of the food F to be heated.

A part of the heated food F to which the atomized water is sprayed refers to a predetermined area where heating unevenness is likely to occur. In a microwave oven that potentially causes unevenness, the nozzle 4a is installed so that the atomized water is properly sprayed on a surface where heating unevenness is likely to occur when viewed from the food F to be heated. Further, even in the case where the turntable 2 is provided as in the present embodiment, the partial region of the food F is the same as that without the turntable 2.

The spot sprayer 4 comprises a water tank 6 containing tap water or alkaline ionized water, which will be described later, and a water supply pipe 7.
The operation is controlled by a command signal p sent from a central control unit 8 comprising a microcomputer. That is, when a start button (not shown) is turned on, a signal q for operating the microwave generation means is sent from the central control unit 8, and the microwave is introduced into the heating chamber 1. At the same time, the command signal p is sent from the central control unit 8 to the spot sprayer 4, and the atomized water is sprayed from the nozzle 4a toward a partial area of the food F to be heated. Also,
Information r such as the amount of remaining water in the water tank 6 is monitored by the central control unit 8.

Reference numeral 9 denotes a non-contact temperature sensor for detecting the surface temperature of the food F to be heated, which includes a light receiving portion 9a facing the heating chamber 1 at a predetermined angle, a detection signal amplification circuit, a detection temperature correction circuit, and the like. And a detection signal processing circuit 9b. Note that a Fresnel lens is generally used for the light receiving unit 9a, and the detection range is limited to a predetermined surface angle by this lens. A is a visual field on the heated food F detected by the light receiving unit 9a, and B is an infrared heat ray radiated from the surface-part of the heated food F included in the visual field A. Further, s is a surface temperature signal of the food F to be heated, which is detected by the temperature sensor 9 and sent to the central control unit 8. Further, t is a drive control signal and a rotation position detection signal from the central control unit 8 for the rotation of the turntable 2.

FIG. 2 shows the food to be heated F in the present embodiment.
In principle shows partial heating. In this embodiment, first, as shown in FIG. 2 (A), half of the heating time necessary for the content of the food F to be heated is spent, and first, a certain amount of the food F is heated by microwave heating. Is heated. Next, as shown in FIG. 2 (B), the temperature sensor 9 detects a heating unevenness which is inevitably generated, that is, a portion which is lower in temperature than other portions due to the entire heating degree and the heating unevenness.

Then, as shown in FIG. 2 (C), atomized water is spot-sprayed partially on a part which is underheated more than other parts due to uneven heating, and thereafter, FIG. As shown in ()), the remaining half of the required heating time is heated by microwaves. At this time, the microwaves act strongly on the food parts to which the atomized water subjected to the spraying treatment by the spot sprayer 4 adheres, especially since the dielectric loss coefficient becomes large.
Thereby, the temperature of the part where the atomized water is applied rises faster than that of the part where the atomized water is not applied, so that the uneven heating can be effectively reduced.

FIG. 3 shows a schematic processing flow during heating and cooking including partial heating of the food F to be heated. First, after heating and cooking are started, microwave heating is performed for half the predetermined heating time by the food F (steps # 1 and # 2). Next, the surface temperature of the food material F is measured by the temperature sensor 9 as a value of 1
Detection is performed while storing the memory for the circumference (step # 3). Further, it is determined based on a predetermined standard whether or not the heating unevenness has occurred in the food material F, and the insufficient heating portion is searched for from the next round of the turntable 2 (steps # 4 and # 5).

Then, when the under-heated portion enters the aim of the nozzle 4a, the rotation of the turntable 2 is slowed down or stopped, so that the spraying process is easily performed accurately (step # 6,
# 7). Next, the food is heated to the same temperature as the surface temperature of the food F by the amount of the atomized water to be sprayed, and sprayed on the underheated portion of the food F
(Step # 8). Finally, the rotation of the turntable 2 is returned to the normal speed, the other half of the microwave heating time is corrected to an appropriate time from the surface temperature of the food F and the amount of atomized water spray, and microwave heating is performed for the remaining time ( Step # 9, Step # 10). In FIG. 3, the TT in step # 9 is shown with the turntable 2 omitted.

Hereinafter, the configurations, functions and operations of the respective components such as the spot sprayer 4 and the non-contact temperature sensor 9 will be described more specifically.

According to the configuration in which the spot sprayer 4 is provided, the atomized water is heated during the heating by the microwave.
Is sprayed on some areas. That is, in general, a microwave oven radiates microwaves to the heating chamber 1 from one or two points, but is placed at the center of the chamber with the inner wall of the heating chamber 1 formed in a rectangular parallelepiped shape as a reflection surface. The heated food F in various forms is heated, but it is very difficult to apply uniform heating over the entire food, and therefore, uneven heating occurs more or less. When the heat capacity of the food F is large, the heating time naturally increases, but as the heating time increases, the temperature difference due to uneven heating increases.

In the present embodiment, the temperature difference is reduced by performing atomized water spraying by the spot sprayer 4. In this case, the water is considered to have a larger dielectric loss coefficient in microwaves than the general food F to be heated, but the degree of heating of this water (atomized water) is delayed due to uneven heating generated during heating. By spraying on the food material portion, the sprayed portion can more easily absorb microwaves after the spraying, so that uneven heating can be actively corrected.

As means for generating atomized water in the spot sprayer 4, as shown in FIG. 4A, water supplied from a water tank 6 is heated by a steam generator 4b to generate steam, and 4a. In this configuration, high-temperature steam is obtained by the steam generator 4b, but it is known that the high-temperature steam has a low dielectric loss coefficient with respect to microwaves, and the high-temperature steam is atomized from the nozzle 4a to a partial region of the food F to be heated. This is effective when water is sprayed to finely correct uneven heating.

Further, as shown in FIG.
Is guided to a shallow tray (not shown), and is scattered by hitting the water surface with ultrasonic waves by a vibration actuator 4c to form atomized water. In this case, since the low-temperature water is miniaturized and scattered, the low-temperature water can be sprayed on the food F while maintaining a high dielectric loss coefficient with respect to microwaves. Therefore, it is effective in efficiently correcting uneven heating.

Further, as shown in FIG. 4 (C), there is a type in which water is scattered by a compressed gas supplied from a compressed gas supply source 4d. As the compressed gas supply source 4d, a pressure vessel such as a cylinder for compressing a gas and storing it in a liquefied state, or a cylinder filled with a compressed gas is separately prepared, and the cylinder is incorporated in advance. thing,
Alternatively, a means for collecting the surrounding air with an electric pump or the like to generate compressed air can be used.

Further, a compressed gas output control means is provided, and a water passage is formed immediately before the nozzle 4a so as to join the water in the water tank 6, and water for atomization is sucked up by the pressure accompanying the discharge of the compressed gas. 1 together to form atomized water.

FIG. 4 (C) shows the most vigorous spray form among the three shown in FIGS. 4 (A) to 4 (C), and it is desired to limit the point of partial heating due to uneven heating to a small value. Is effective. Also, turntable 2 can be used together,
When performing high-capacity microwave heating, it is necessary to perform spraying of a predetermined amount of water in an extremely short time, but this is also an effective means.

Since the amount of water required for the atomized water is extremely small compared to the capacity of the food F to be heated, it does not affect the heating of the main food. The heat is immediately taken away by the atomized water, and the effect is that only that part cools down.

Further, when atomizing water having a temperature different from the current surface temperature is sprayed on the food material F, the following problems may be caused at each of a low temperature and a high temperature. In other words, when the atomized water is at a low temperature, the portion underheated due to the non-uniform heating due to the atomized water has a lower temperature. Conversely, when the temperature is high, the food F reaches the target cooking completion temperature early due to the effect of the atomization water temperature, and when the heating is completed, the food F is insufficiently heated. In this case, the atomized water remains as it is, resulting in a watery finish, which may impair the taste and color. Thus, by approximating the temperature of the food F and the temperature of the atomized water, the above-mentioned concerns can be resolved.

However, the microwave irradiation energy is too large to heat the amount of water (about several cc) required for the atomized water. For this reason, it is necessary to control the heating amount of the atomizing water by another means to make it an appropriate temperature. The heating of the atomized water is performed before the atomization. However, as described above, the temperature is approximated to the surface temperature of the portion of the food F to be heated which has been insufficiently heated due to the uneven heating, and is cooled. It is desirable not to do so and to avoid unnecessary heating.

As shown in FIG. 5, for example, the atomizing water heating means is constituted by a heater 10 arranged around a water supply pipe 7 between the water tank 6 and the spot sprayer 4.
Heating the water inside by the heater 10 makes it possible to vaporize and generate atomized water. By appropriately heating the temperature of the atomized water by the heater 10 in this way, it is possible to prevent the food F from being cooled by spraying the atomized water onto the food F.

Although not shown, a part of the water supply pipe 7 up to the spot sprayer 4 is exposed to the heating chamber 1 instead of the simple heating method using the heater 10 shown in FIG.
May be configured so that part of the microwave irradiation for heating the water supply system also reaches a part of the exposed water supply system. Since liquid water is supplied to this exposed portion, it is desirable to form a stagnation in the portion that is most strongly irradiated so as to stably irradiate the microwaves and to prevent a continuous water flow. However, in a configuration in which a part of the water supply pipe 7 from the water tank 6 to the spot sprayer 4 is exposed to the heating chamber 1, the efficiency is relatively reduced.

Therefore, as a more efficient means for heating atomized water, as shown in FIG. 6, a tray 11 to which a required amount of water in a water tank 6 is supplied is provided on a wall 1a or 1a of the heating chamber 1.
b, an opening 1c is provided on the wall of the heating chamber so that a part of the tray 11 is irradiated with microwaves, and a necessary amount of water is extracted from the water tank 6 to the tray 11,
One in which water in the tray 11 is heated and vaporized by microwaves extending from the opening 1c to the water surface. In this case, since microwave irradiation for heating the food is used, there is also an advantage that the means for preheating the atomized water can be configured at a relatively low cost.

In this configuration, the tray 11 can hold a small amount of water enough to supply the spot sprayer 4 one or two times to be microwave-heated. Is generated, and preheating is performed on the tray 11 until the atomization water spraying process is performed to suppress the unevenness.

In this case, the amount of heating for preheating the atomized water is very small compared to the amount of heating for heating the foodstuff F. Therefore, in order to adjust the temperature to the desired suitable temperature and heat it, it is necessary to perform micro heating in multiple stages. A mechanism that can adjust the amount of waves applied to the tray is required. This adjusting mechanism partially changes the shape of the microwave irradiation surface of the tray 11 to be irradiated with microwaves so that the degree of microwave irradiation can be appropriately changed. And a method in which two plates having a plurality of slits are relatively slid to change the slit opening area.

Specifically, as shown in FIG.
c may be provided with an opening and closing mechanism. In this opening opening / closing mechanism, the opening 1c is constituted by a plurality of slit-shaped windows, and a plurality of shielding plates 12 having substantially the same width as the slit width are slidably disposed along the opening 1c. , The slit width is variable. This makes it possible to finely adjust the degree of heating with higher accuracy.

With respect to the slit width, if the microwave is preheated with a heating capacity of 100%, it may boil immediately due to a small amount, so that it is more than one wavelength of the microwave even in the fully opened state. For example, by making the wavelength to be a quarter wavelength when fully opened and adjusting it in a plurality of stages until fully closed, it is possible to produce an appropriate temperature of the preliminary water for atomizing water.

The non-contact temperature sensor 9 is provided in the heating chamber 1 for the purpose of making the above-mentioned atomized water temperature equal to the surface temperature of the food F, and detects the food surface temperature in a non-contact manner. Is what you do. That is, while heating the food F to be heated by the microwave, the temperature sensor 9 determines the degree of heating and which portion has uneven heating.
By detecting the food material surface temperature, a relatively low temperature portion due to uneven heating is detected, and atomization water spraying is performed.

As the non-contact temperature sensor 9, there is a bolometer type thermistor temperature sensor. This bolometer-type thermistor temperature sensor is composed of two or more thermistors, one of which is a black thermistor (detection side) and efficiently absorbs radiant infrared heat rays by a concave mirror, a Fresnel lens, or the like. The other (correction side) that does not affect the reception of radiant infrared heat rays is a structure such as a silver thermistor or a shielding plate coated with silver paint, and has a structure that cannot directly receive infrared rays emitted from the detected object. The purpose is to measure the ambient temperature or to correct the fluctuation of the ambient temperature. Both are in direct contact or indirectly through a thin printed circuit board.

The detection side thermistor occupies most of the detection amount in the ambient temperature, and the amount that changes by receiving infrared light is very subtle. That is, if the detection side and the correction side are installed at different positions, different ambient temperatures are detected, and the detection result becomes completely unreliable. Therefore, it is desirable that the relative positional relationship between the two be as close as possible. It is also desirable to adopt a structure that does not easily cause a change in ambient temperature, such as blocking airflow.

Further, if the shape of the thermistor itself becomes small, it can cope with an instantaneous change in the temperature of the object to be detected. However, the amount of received light decreases, and it is easily affected by disturbances such as electrical noise and subtle changes in the surrounding environment. Become. As described above, the bolometer-type thermistor temperature sensor has considerable technical problems in installation and the like, but has an advantage that it can be configured at the lowest cost.

Another non-contact temperature sensor 9 is a thermopile. In other words, when performing microwave heating, in order to concentrate the microwaves dispersed in one direction from one waveguide so as to wrap around one food material F from around, the microwaves are appropriately reflected on the inner wall of the heating chamber 1. Need to be done. However, while microwaves diverge concentrically, the inner wall of the heating chamber 1 is formed of a rectangular parallelepiped wall, so that the above-described standing wave is concentrated near the center of the heating chamber. Is impossible and uneven heating is inevitable.
Therefore, what is needed is information on the current heating progress status and the location where uneven heating has occurred. As this information collecting means, a thermopile capable of grasping the absolute surface temperature in a non-contact manner is suitable. Although the thermopile is expensive, it has a high response speed and is very suitable for grasping the situation of the food F rotating on the turntable 2.

As another temperature sensor 9, a chopper type pyroelectric sensor can be mentioned. The pyroelectric sensor reacts to a change in the amount of infrared heat ray radiation to be received, and cannot detect the absolute surface temperature of the food material F by itself. For this reason, a shielding plate capable of grasping the surface temperature is disposed in front of the pyroelectric sensor, and the pyroelectric sensor is periodically shielded by the shielding plate. Is detected in a non-contact manner. This periodic shielding mechanism is called a chopper. Although the detection accuracy is lower than that of the aforementioned thermopile, it is advantageous in that it is relatively inexpensive.

The aim detected by the non-contact temperature sensor 9 is made as equal as possible to the aim of the spot sprayer 4, that is, the optical axis which is the target of the temperature sensor 9 is
By setting the position close to the target, it is possible to accurately control the temperature and amount of atomized water emitted from the spot sprayer 4 in accordance with the situation detected by the temperature sensor 9.
Specifically, if the portion detected by the temperature sensor 9 is a portion that requires heating correction, the same portion can be subjected to the atomization water spraying process.

In order to properly perform the atomized water spraying process, the heating condition of the food F to be heated is grasped by the temperature sensor 9, and the area detected by the temperature sensor 9 and the spray area of the spot sprayer 4 are as large as possible. If the distance from the center of the turntable 12 to the temperature sensor 9 or the distance to the nozzle 4a of the spot sprayer 4 is the same, the light receiving surface angle of the temperature sensor 9 and the spray of the nozzle 4a are equal. By making the radiation surface angle the same, the area on each food material surface becomes equal.

Thus, the temperature sensor 9 or the nozzle 4a
Even if the distance from the food to the food F is short or fast, the temperature detection region and the atomized water spray region are almost similar. The surface temperature detected by the temperature sensor 9 is the average temperature of the area divided by the predetermined plane angle, and by adjusting the spray area of the spot sprayer 4 to cope with the result according to the result, the uneven heating is achieved. Can deal only with the place where the underheating is actually detected.

In this embodiment, when the food F is placed on the turntable 2 and heated, the spot sprayer 4
The target of the temperature sensor 9 is a relative positional relationship that becomes an approximate position when rotated by a predetermined angle around the rotation axis of the turntable 2. The time required for the turntable 2 to rotate by this predetermined angle is the time required for the temperature sensor 9 to detect a low-temperature portion due to uneven heating, calculate the amount of atomized water spray corresponding to the corrected temperature difference, and perform the spraying process. Becomes

That is, the predetermined angle means that the temperature sensor 9 detects the surface temperature of the food material F, determines whether or not a part of the food material F needs to be spot-sprayed. Performs temperature control of the atomized water, calculates the amount of atomized water spray according to the surface temperature, and corresponds to a series of times until the timing until a part of the food F comes to the front of the spray nozzle is adjusted. And turntable 2
Must be greater than or equal to the angle of rotation. If the temperature is small, the timing of the spraying process is delayed, and spraying may be performed on a location shifted from the location where the temperature is detected, thereby further generating uneven heating.

When the turntable 2 is used in combination with the spot sprayer 4 as described above, the temperature sensor 9 for detecting a low-temperature portion of the uneven heating and the spot sprayer 4 for partial heating are used.
However, even if it is not installed extremely close to the structure, if the heating chamber side surface 1b is at the same elevation angle from the turntable 2, the condition seen from the food F by rotating the turntable 2 can be made equal.

The means for judging whether or not it is necessary to perform the spraying process by the spot sprayer 4 is as follows.
, And saves them in the memory of the central control unit 8, and extracts the highest temperature point, the lowest temperature point, and the place where the lowest temperature is detected from the surface temperature data collected in one round, If the difference between the highest temperature and the lowest temperature is equal to or higher than the predetermined temperature, the spraying process is performed by the spot sprayer 4 in a procedure described later, and if it is less than 1, the surface temperature of the food F is detected again by one rotation. It waits until the place where the lowest temperature is detected in the next round rotates in front of the nozzle 4a for performing the spraying process by the spot sprayer 4, and performs the spraying process at the time of the front.

If the atomization water spraying process is performed frequently, there is a possibility that the food material F becomes watery or the taste and freshness are impaired. Therefore, it is desirable to perform the above-mentioned processing only when heating unevenness occurs remarkably, and as a reference of the degree of “prominence”, it is assumed that the maximum temperature and the minimum temperature are equal to or more than a predetermined temperature difference. By this, the spraying process is performed at a minimum, and the amount of the atomized water adhered to the food material F is heated by the microwave heating thereafter, prior to the food material heating, and the atomized water itself is heated.
When the heating is completed, the atomized water is vaporized and acts on the food heating as heat, and finally, the atomized water does not remain in a state attached to the food F.

Here, by using a temperature difference from the average temperature for one round instead of comparing with the maximum temperature point, erroneous processing in detecting an abnormal maximum temperature due to a measurement disturbance can be reduced. That is, when determining the temperature difference based on the maximum temperature, if an electrical or thermal disturbance element occurs temporarily during the temperature detection process, and based on the data that happens to be obtained as the maximum temperature, Even if there is no heating unevenness, the spraying process by the spot sprayer 4 may be performed, which may cause extra heating unevenness. Therefore, the average temperature is used as the reference data as a means for reducing the specific gravity of the erroneous detection.

Further, if the same spraying process is performed regardless of the state of the food F to be heated, it is difficult to delicately deal with the state of the food F to be heated. Therefore, it has a function of changing the spray amount of the atomized water, and adjusts the spray amount of the atomized water according to the temperature difference between the reference temperature and the minimum temperature. When the temperature difference is small, the amount of spray is reduced, and delicate follow-up heating by microwave is promoted. By making the amount of atomized water spray variable according to the temperature difference, a delicate partial heating process can be performed according to the degree of uneven heating generated by microwave heating.

By the way, although it is possible to determine to what extent heating unevenness is likely to occur due to the housing structure of the microwave heating range, it is possible to know the dielectric loss coefficient of the food F actually heated. Depending on factors such as shape and weight, the location and degree of occurrence of uneven heating vary. Therefore, the food material F is heated by actually irradiating microwaves to some extent, and spray processing by the spot sprayer 4 is performed according to the actually generated uneven heating. After the spraying treatment, the atomized water adhered to the food F is further concentratedly heated by microwave heating to suppress uneven heating, so that this heating time is also required. Therefore,
Since a uniform heating time is required before and after the spraying process, it is desirable to perform the spraying process by the spot sprayer 4 at half the time of the entire heating time.

That is, the spraying process by the spot sprayer 4 is performed by grasping the spot of the heating unevenness to be performed each time, so that the microwave heating is performed to such an extent that the heating unevenness can be understood before the spraying process is performed. Need to be kept.

For example, in the case of a microwave oven in which an arbitrary menu can be selected before cooking, when a menu is selected, an appropriate heating time is set in advance based on advance information such as the type, amount, and heating preference of the food F to be heated. Have been. Therefore, in the present embodiment, the heating state of the food F to be heated is determined by the temperature sensor 9.
The detection is performed when a half of the appropriate heating time set as the provisional value has elapsed, and at that time, the spraying process by the spot sprayer 4 is performed.

The insufficient heating caused by the uneven heating due to the spray treatment is locally heated for the remaining half of the heating time, and finally the aim is to compensate for the uneven heating. However, even if there is uneven heating, if the degree of heating has already progressed from a predetermined heating state, spraying is not performed and overheating is prevented when cooking is completed. That is, in order to achieve the target value of the final surface temperature at the time of completion of heating, the surface temperature at this point is compared with a predetermined temperature, and if the temperature is achieved, spraying here may cause overheating. For this reason, this process is not performed, and spraying is performed only when the process is not achieved, thereby promoting partial heating. In this case, the central control unit 8 is provided with a nonvolatile memory having table data that can be extracted in advance for the type, capacity, weight, and target temperature of the food F, and a predetermined temperature is extracted based on the table data.

When half of the proper heating time has elapsed, the remaining half of the heating time is left as it is, and if heating is further performed, finally, when cooking is completed, whether heating is insufficient or overheating is determined.
From the surface temperature at that time, the heating time of the other half is finely adjusted. As a means for this estimation, it is used as a standard whether or not the target temperature at the completion of heating of the food F is higher than the target temperature if the surface temperature rise gradient during the half cooking time is continued as it is.

That is, in the first half of the microwave heating until the spraying process is performed, the heat capacity of the foodstuff F is temporarily calculated from the time and the temperature rise, and the second half of the microwave heating is performed at the same heating pace. Then, the surface temperature when the final heating is completed is estimated and calculated, and if it exceeds the target value, the spraying process is stopped.

Next, if the spraying process is performed only because the heating unevenness has occurred, there is a possibility that the heating process may be overheated when the heating is completed. Provide. As a result, the risk of failure of overheating that cannot be reversed can be reduced as much as possible, rather than the somewhat uneven heating unevenness.

If the appropriate heating time is set based on the information grasped before heating among the kind, shape, weight, etc. of the food to be heated F and the target temperature at the time of completion of heating, microwave heating is performed. Basically, the food F should be finished to the target temperature, but the pre-input information indicates that the food F
Many cases do not match with. This is because, in a microwave oven, generally, the menu of the proper heating time for the information such as the type, shape, and weight of the food F to be heated is managed, and the data by the menu management actually tries to heat. This is because even if it is similar to the food F, it cannot be said that it is the same. Furthermore, the probability that the shape is different from the one assumed in the menu is higher. Therefore, it can be said that the menu management method is merely a guide.

Then, by calculating the degree of heating and the rate of temperature rise per unit time by the temperature sensor 9 during the heating, fine adjustment of the heating time as much as possible to the condition of the food F actually heated is possible. In this manner, insufficient heating and overheating can be prevented.

Specifically, the necessity of performing the spraying process by the spot sprayer 4 and the information such as the spray amount, the appropriate atomizing water temperature, and the spray position are based on the detection of the food material surface temperature by the temperature sensor 9 before the spraying process. If the surface angle area to be detected by the temperature sensor 9 and the food surface partial area to be sprayed are shifted, the detection result cannot directly correspond to the spraying processing. In order to perform accurate processing, it is necessary to make the distance to the food material F equal and make the detection surface angle and the spray radiation angle equal.

Further, if a deviation occurs in the rotation direction of the turntable 2, a problem occurs. That is, the temperature sensor 9
When the relative positional relationship between the nozzle 4a and the nozzle 4a of the spot sprayer 4 is different, the presence or absence of uneven heating and the location that needs to be dealt with are detected according to the surface temperature of the food F detected by the temperature sensor 9, and the location is accurately determined. When the turntable comes two turns to the front of the spray nozzle, spray processing must be performed.

Therefore, the central control unit 8 is provided with means for detecting the rotational position of the turntable 2 to accurately manage whether or not the surface to be detected has come in front of the spray nozzle. In order to further increase the rotational alignment accuracy, when the surface to be detected approaches the front of the spray nozzle (when the surface enters the range of the turntable 2 which has been increased or decreased by a predetermined numerical value of the minimum resolution for position detection), the turntable 2 The rotation of the turntable is stopped at the time when the rotation speed of the nozzle is lowered or when the turntable is rotated two times when the nozzle enters the front of the nozzle, so that the displacement caused by the rotation during the time required for spraying is eliminated.

Further, there is a state where the atomized water that has not adhered to the food material F due to the spraying process is temporarily floating in the heating chamber 1. That is, if the spraying process is performed during microwave heating,
Since water is concentrated at the tip of the spray nozzle, the atomized water sometimes floats in the heating chamber 1 and does not adhere to the food material F. Microwaves are concentrated at the end of 4a, and the atomized water receives extra heating at the end of the nozzle.

At this time, if the detection process of the temperature sensor 9 for grasping the condition of the food F is performed, the temperature of the floating atomized water other than the actual surface temperature of the food F may be erroneously detected.
Therefore, the temperature sensor 9 may erroneously detect the temperature of the aggregate of the atomized water having a certain degree of heat, and thus the period during which the atomized water may be floating, that is, the period during which the spot sprayer 4 is performed. In addition, the non-contact temperature detection is not performed for one second after the processing from the viewpoint that reliability is poor.

In general, a microwave oven is provided with a heating chamber 1 in order to prevent the heating chamber 1 from being obstructed by the steam generated by heating the food material F or causing a problem of dew condensation.
However, when performing the spraying process, there is a case where the atomized water does not travel straight from the nozzle 4a due to the supply of the air current. In such a case, if the spray is shifted to a portion other than the portion to be sprayed, uneven heating is further increased, and the temperature difference between the high-temperature portion and the low-temperature portion increases.

Therefore, in this embodiment, the spot sprayer 4
During the period of the spot sprayer 4 and one second before and after, the direction of the air flow supplied to the heating chamber 1 is directed to the wall surface of the heating chamber 1 distant from the food material F so that the target point can be sprayed accurately. The direction is variable so that the turbulence of the spray of the atomized water due to the air flow is reduced.

FIG. 7 shows the configuration of the nozzle 4 a of the spot sprayer 4. FIG. 7A shows a state during atomization of water spray, and shows that the nozzle 4a does not project from the wall surface of the heating chamber. FIG. 7 (B) shows a state after atomization water spraying. First, immediately after the spraying, water remaining in the pipe of the nozzle 4a at the time when the spraying is ended is hung as a residual water droplet x at the tip of the nozzle 4a by the action of surface tension. It shows the state where it was turned on. FIG. 7C shows a state in which the residual water droplet x is sucked and removed by the negative pressure m from inside the nozzle 4a.

After spraying the atomized water from the nozzle 4a of the spot sprayer 4, a water droplet m as shown in FIG. 7B tends to remain at the tip of the nozzle 4a. If microwave heating is further continued while the residual water droplet m is left as it is, the residual water droplet m itself is heated by the subsequent microwave heating, and the nozzle 4a may become hot. In addition, when the next spraying process is performed, the overheated high-heat atomized water is sprayed on the food F, which makes it difficult to make the temperature equal to the food surface temperature.

Therefore, immediately after spraying the atomized water from the nozzle 4a, the water droplet m remaining at the tip of the nozzle 4a is sucked from the inside of the nozzle 4a as shown in FIG. Other than the above, the state where there is no moisture at the tip of the nozzle 4a is always maintained. By doing so, the remaining water droplet m is heated by the subsequent microwave heating, the nozzle 4a becomes hot, and when the next spraying process is performed, the atomized water is too hot and the food surface temperature becomes too high. It will not be difficult to make it equal to.

For example, there is an existing microwave oven, and the temperature sensor 9 and the nozzle 4a of the spot sprayer 4 are added as additional specifications.
When such a component is additionally installed on the wall surface of the heating chamber, a part of the food F placed in the center of the bottom surface may protrude into the heating chamber 1 for the purpose. In addition, since it is necessary to narrow the radiation surface angle to an acute angle in a spot, the nozzle 4a necessarily has a thin and protruding shape. Therefore, if the nozzle 4a protrudes from the wall surface of the heating chamber, there is a possibility that the distribution of the heating chamber of the microwave is disturbed by using the tip of the nozzle 4a as an antenna, and the microwave is concentrated to generate a discharge. In this case, Further, uneven heating will be enhanced.

Therefore, in order to realize an ideal microwave distribution in the rectangular parallelepiped heating chamber 1, as shown in FIG. 7A, the nozzle 4a is formed to have a pointed tip and the heating chamber 1 By providing an arrangement that can perform the ideal microwave distribution, the function of the stub that is generally applied is
It is preferable that the nozzle 4a is also used.

Further, it is difficult to devise the shape or arrangement of the temperature sensor 9, which has many optically limited installation conditions. Therefore, the nozzle 4 is designed to reduce the disturbance of the microwave distribution caused by the presence of the temperature sensor 9.
Determine the position and shape of a. However, if the tip of the nozzle 4a is shared as a stub in this manner, a strong restriction is imposed on the position condition, and it may be difficult to spray the atomized water to an accurate point of the food F.

The heating chamber 1 has a temperature sensor 9 and a nozzle 4
If the protrusions such as “a” protrude, for example, if the nozzle 4a is exposed to the heating chamber 1, the fragments of the food material F and the splash of the oil in the previous cooking adhere to the tip of the nozzle 4a, and In addition, another foodstuff F may be subjected to a spraying process together with the previous contamination, which is not desirable in terms of sanitation.

Therefore, the nozzle 4a does not project from the wall surface of the heating chamber 1, and the tip of the nozzle is made substantially flush with the wall surface. In addition, by using a structure in which a small hole is formed in the wall surface as the spray port 5, when microwave heating is performed, the presence of the nozzle 4a disturbs the distribution of the microwave heating chamber 1 as an antenna and may cause discharge. Disappears. However, when the structure of the nozzle 4a of the spot sprayer 4 is set to be substantially flush with the wall surface of the heating chamber, the spray port 5 formed by the small holes is blocked by scattering of oil or food fragments generated by heating the food F. However, if a situation occurs in which the hole diameter is further reduced, normal spraying becomes difficult thereafter.

Therefore, as shown by the imaginary line in FIG.
A shutter mechanism that can be opened and closed on the wall surface is provided in the spray port 5 composed of a small hole, and the shutter 1 is used only when spray processing is performed.
3 shall be opened and normally closed. Accordingly, it is possible to prevent the spray port 5 from being closed or the hole diameter to be further reduced by splashing of oil or food F fragments generated by heating the food F.

When the spraying process is performed during the microwave heating, since the water is concentrated at the tip of the nozzle 4a, the microwave concentrates at the point of time before the nozzle 4a before adhering to the food F, and the nozzle 4a Since the atomized water receives extra heating before, the microwave irradiation is temporarily stopped during the spraying process and for 1 second before and after the atomizing process. Resume wave heating. If the atomization water is heated during the spraying process when it does not adhere to the food material F, the surface temperature of the food material F is detected and the atomization water is appropriately warmed to the same temperature. It is meaningless to have been.

Before atomizing the water to be used for atomizing water atomization, in the water tank 4, alkali ion water is generated by physically excess electrons by electrolysis and supplied to the step of generating atomized water. be able to. The water quality of alkaline ionized water containing this ion source is expected to increase its conductivity compared to pure water and to be able to expect effective heating with microwaves. It has been confirmed under the influence of temperature and salinity.

Further, in the spraying process, the atomized water sprayed on the food F is efficiently microwave-heated, and alkali ion water is used as the atomizing water with the aim of effecting partial heating of the low-temperature portion due to uneven heating. I do. in this way,
By spraying the alkaline ionized water onto the foodstuff F, the fibrous foodstuff F swells and softens the fiber cells, the lipid foodstuff F suppresses peroxidation, and the pigment cells in the foodstuff F suppresses pigment degeneration. An effect such as suppression of bacterial survival can be expected.

By the way, when the electrolysis treatment is performed in the water tank 4, the spot sprayer 4 may not be able to be performed at a required timing due to a large amount of water, and the water tank 4 is inevitably not used for the time being. If all of the water inside is converted into alkaline ionized water, the ion molecules may return to a stable original state over time, and the processing itself may be wasted. Therefore, it can be said that it is more convenient to take a step of electrolyzing only a necessary amount of the atomized water immediately before the water is atomized.

[0088]

As described above, according to the first aspect of the present invention,
When the microwave is introduced into the heating chamber by the microwave generating means, the atomizing water is sprayed toward a partial area of the food to be heated by the spot spraying means. In addition, by spraying atomized water having a maximum dielectric loss coefficient on a part of the food to be heated, the efficiency of microwave absorption at the sprayed portion can be increased, and the uneven heating can be actively corrected. .

According to the second aspect, the condition of the uneven heating actually generated by heating the food to be heated to some extent is confirmed by the non-contact temperature sensor, and then the water temperature is insufficiently heated due to the uneven heating of the heated food. It is possible to perform the optimal atomization water spray without approximating the surface temperature of the heated portion, without cooling, and without unnecessary heating.

According to the third aspect, since the spray area by the spot spray means is set to be equal to the detection area of the temperature sensor, the spray from the spot spray means depends on the condition detected by the temperature sensor. The temperature of the atomized water to be sprayed and the spray amount can be controlled accurately. Therefore, it is possible to cope only with the place where it is actually detected that the heating is insufficient due to the uneven heating.

According to the fourth aspect, the spot spraying means is installed at a position displaced from the temperature sensor by an angle corresponding to a series of times required for the operation of the temperature sensor around the turntable. It can be applied to a microwave oven having a table.

According to the fifth aspect, a memory for sequentially updating and storing the surface detection temperature data of the food to be heated from a partial area on the food to be heated which is currently detected every turntable turn, and Since the configuration is such that the operation of the spot spraying unit is controlled based on the difference between the surface temperature data of the food to be heated and the temperature data calculated in advance based on the temperature data in the memory, uneven heating may occur. It is possible to perform the atomization water spraying process only when the spraying occurs significantly, and it is possible to avoid the possibility of impairing the taste of the foodstuff due to the frequent spraying process.

According to the present invention, the food material to be heated at the time when the rotation sensor detects the rotation position of the turntable, at the time when the temperature is detected by the temperature sensor based on the data detected by the rotation detection means, and during the atomizing water spraying process. The atomizing water spraying process timing is adjusted so that the directions of the spraying nozzles are the same, so that even if there is a shift in the rotation direction of the turntable, the surface to be detected for foodstuffs is in front of the spray nozzle. It is possible to accurately manage whether or not it has come, and adjust the rotation speed of the turntable to eliminate a shift due to rotational movement during the time required for spraying.

According to the seventh aspect, since the spot spraying means is provided with the water drop collecting means for sucking and collecting the water drop remaining at the nozzle tip immediately after the spraying process, the water drop remaining after the atomized water spray by the spot spraying means is provided. Can be reliably removed, and the effect of the residual water droplets on the nozzle and the generation of overheated atomized water in the next spraying process can be prevented.

According to the eighth aspect, since the nozzle of the spot spraying means is provided so as not to protrude into the heating chamber from the spray port formed facing the heating chamber, the presence of the nozzle when microwave heating is performed. As an antenna, it is possible to prevent inconvenience such as disturbing the distribution of the microwave heating chamber.

In short, according to the present invention, an appropriate location and an appropriate amount of treatment are determined according to the food situation, and the treatment for uneven heating has become much more realistic than before.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an internal basic configuration of a microwave oven according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view showing the principle of partial heating in order.

FIG. 3 is a flowchart showing an outline of a processing flow during heating cooking;

FIG. 4 is a block diagram illustrating various aspects of means for generating atomized water in a spot sprayer.

FIG. 5 is a schematic view showing an example of atomized water heating means.

FIG. 6 is a schematic diagram showing another example of the atomized water heating means.

FIG. 7 is an enlarged sectional view of a main part showing the operation of the nozzle of the spot sprayer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating room 1a Heating room bottom plate 1b Heating room side wall 1c Opening 2 Turntable 3 Waveguide opening 4 Spot sprayer 4a Nozzle 5 Spray port 6 Water tank 7 Water supply pipe 8 Central control unit 9 Non-contact temperature sensor F Heated food material

Claims (8)

[Claims] 1. A microwave heating apparatus comprising: a heating chamber for accommodating a food to be heated; and microwave generating means for introducing a microwave for heating the food to be heated into the heating chamber. A microwave heating device, comprising: spot spraying means for spraying atomized water toward a partial region of the food to be heated when microwaves are introduced into the heating chamber. 2. A non-contact type temperature sensor for measuring a partial surface temperature of a food to be heated is provided in a heating chamber, while a spot spraying means includes a water heating means for preheating water, and a water heating means. 2. A micro water generating means according to claim 1, further comprising water temperature control means for adjusting the water temperature so as to approximate the water heating temperature by the temperature sensor to the partial surface temperature of the food to be heated measured by the temperature sensor. Wave heating device. 3. The microwave heating apparatus according to claim 2, wherein a spray area by the spot spray means is set to be equal to a detection area of the temperature sensor. 4. A turntable for mounting a food to be heated, which is rotationally driven when microwaves are introduced into the heating chamber by the microwave generation means, is provided on the bottom surface of the heating chamber.
4. The microwave heating apparatus according to claim 2, wherein the spot spraying unit is disposed at a position displaced from the temperature sensor by an angle corresponding to a series of times required for operation of the temperature sensor around the turntable. . 5. A memory for sequentially updating and storing the surface detection temperature data of the food to be heated from a partial area on the food to be currently detected every turn of the turntable, and a memory for detecting the temperature of the currently detected food to be heated. 5. The apparatus according to claim 4, further comprising: a first spray control unit configured to control an operation of the spot spray unit based on a difference between the surface temperature data of the food material and the temperature data previously calculated based on the temperature data in the memory. Microwave heating equipment. 6. The direction of the heated food at the time of detection by the temperature sensor based on the detection data of the rotation detecting means for detecting the rotation position of the turntable and the rotation detecting means and the time of the atomization water spraying process is equal. The microwave heating apparatus according to claim 4 or 5, further comprising a second spray control means for adjusting the timing of the atomization water spray processing. 7. The microwave heating apparatus according to claim 1, wherein the spot spraying unit includes a water droplet collecting unit that suctions and collects a water droplet remaining at a nozzle tip immediately after the spraying process. 8. The microwave heating apparatus according to claim 1, wherein the spot spraying means is provided so that the nozzle does not project into the heating chamber from a spray port formed facing the heating chamber. .