JPH0676942A - Heating cooking unit - Google Patents

Abstract

PURPOSE:To provide constitution by which thawing can be carried out up to a frozen part nonexistent condition without boiling an object to be thawed when the thawing of fish meat and the like is carried out in a high-frequency heating cooking unit. CONSTITUTION:A heating cooking unit is composed of a heating chamber 1, a high frequency generator 4, a wave guide 8 to connect these to each other, a radio wave agitating blade 6 to agitate high frequency and a rotary loading stand 2 on which food is loaded, and a power supply port 5 of the wave guide 8 is arranged on the rear wall of the heating chamber 1, and the radio wave agitating blade 6 is arranged in the wave guide 8. In this constitution, in the case where the rotation axis of the rotary loading stand 2 and a rotation axis of the radio wave agitating blade are made to cross each other at an approximately right angle, since high frequency is radiated approximately symmetrically to the rotation axis of the rotary loading stand 2, when the rotary loading stand 2 is rotated, a difference in heating between the central part and the periphery of the rotary loading stand 2 is hardly caused, so that a food can be thawed uniformly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating device,
In particular, the present invention relates to a structure for increasing the uniformity of heating by high-frequency electromagnetic waves in the heating chamber to the extent that frozen fillets and frozen meat of seafood, which require the most uniform degree of heating, can be sufficiently satisfied.

[0002]

2. Description of the Prior Art As a means for thawing frozen foods, high-frequency heating is characterized by a short time and the like. On the other hand, the degree of high-frequency heating between iced state and thawed state is 1000. Since it is heated about twice as much, if it is thawed somewhere somewhere, it will be heated abnormally strongly and will boil, and the other part will still be in the state of ice, so the high frequency Satisfactory thawing performance cannot be obtained unless the heating uniformity is sufficiently improved.

Conventionally, many methods for uniformly heating an object to be heated in a heating chamber have been proposed. A stirring blade method for agitating high-frequency electromagnetic waves, a rotary mounting table method for rotating an object to be heated, and electromagnetic waves are radiated. Several methods such as rotating the antenna have been proposed. There is also a system that combines both of them and has both a stirring blade system and a rotary mounting system.

A typical example of this is Japanese Patent Publication No. 60-25875.
As shown in FIG. 3, a rotary mounting table is provided on the bottom surface of the heating chamber, and a stirring blade is arranged at the rear part of the heating chamber to uniformly heat the object to be heated in the heating chamber.

As shown in FIG. 9, a rotary mount 34 is provided on the bottom surface of the heating chamber 33. A metallic radio wave agitating blade 37 is provided on a hollow portion 36 of the heating chamber rear wall 35, and a heating chamber 33 is provided through a waveguide 39 provided on the heating chamber upper wall 38.
The electromagnetic wave radiated inside is stirred by the electromagnetic wave stirring blades 37, the rotary mounting table 34 is rotated, and the object 40 to be heated is rotatively moved to achieve uniform heating.

However, in this configuration, not all the high frequency electromagnetic waves radiated into the heating chamber 33 through the waveguide 39 are stirred by the radio wave stirring blade 37, so that the stirring effect is not sufficient, and Since the waveguide 39 is provided on the upper wall 38 of the heating chamber, the upper part of the load tends to be heated a lot, and normally, in an electric heating device-added heat cooker in which electric heating devices are provided above and below the heating chamber, The configuration of the upper heater is difficult because of the waveguide 39, and there is a problem that it is difficult to obtain a sufficient heater heating distribution.

Further, as shown in US Pat. No. 2,748,239, an opening for high frequency electromagnetic waves is provided in the rear wall of the heating chamber, and a wave stirring blade is provided in a waveguide connected to the opening to rotate the wave. Although the electric field of high frequency electromagnetic waves in the heating chamber is to be made uniform, there is a tendency that the rear part of the object to be heated such as food is heated strongly because the opening is provided behind the heating chamber. The same tendency does not change even if the high-frequency electromagnetic wave is stirred by the stirring blade, so that in the thawing that requires a high degree of high-frequency electromagnetic wave homogeneity, a part of it was boiled and part of it remained iced.

Further, in US Pat. No. 4,136,271, there is proposed a method in which an antenna for radiating high frequency electromagnetic waves and a radio wave stirring blade for stirring high frequency electromagnetic waves are arranged on the upper portion and a rotary mounting table is arranged on the bottom surface. Has been done. However, in this method, since the antenna and the radio wave stirring blade are close to each other, the stirring effect of the radio wave stirring blade is sufficient, but it is difficult to reach the central portion of the rotary mounting table because the electromagnetic wave supplying portion is at the top. It was difficult to balance the heating between the central portion and the outer peripheral portion of the rotary mounting table, and the outer peripheral portion inevitably had more heating, and as a result, uniform heating could not be achieved. When there is an electromagnetic wave supply part on the upper part, the electromagnetic wave from the upper part is once reflected on the side surface of the heating chamber and reaches the surface of the rotary mounting table, so that the size of the heating chamber and the position of the upper supply part are slightly changed. There was a drawback that the degree of heating near the surface of the rotary mounting table greatly changed. In addition, when milk or the like is put in a cup and warmed, the upper part is inevitably heated strongly.

In any of the methods, the homogeneity of the electromagnetic wave was not increased to the level where uniform thawing was possible.
Moreover, there was nonuniformity in general heating.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems. That is, it is an object of the present invention to provide a heating device capable of thawing fish meat in a high-frequency heating device when the fish meat is thawed without boiling the object to be thawed and without ice.

It is another object of the present invention to eliminate the disadvantages of uneven heating such that the upper part is hotter even when warming milk or the like, and the disadvantage that the corners are heated strongly when heating an object having a corner. To do.

It is another object of the present invention to provide a heating device which can be easily constructed even when a heater is provided in a heating cooker and which does not have uneven heating.

Another object of the present invention is to provide a heating device having a simple structure, excellent assemblability, excellent durability and reliability, and safe and robust even during abnormal use by a user.

[0014]

In order to achieve the above object, the heating cooker of the present invention has the following constitution.

A heating chamber for heating an object to be heated in the main body, a high frequency generator for generating high frequency electromagnetic waves, a waveguide for guiding the high frequency electromagnetic waves of the high frequency generator to the heating chamber, and the object to be heated. A rotation mounting table that supports and rotates with it, and a radio wave agitating blade that agitates high frequency electromagnetic waves in the heating chamber are provided, and the power feeding port of the waveguide is disposed on the side surface of the heating chamber and faces the power feeding port. The wave stirring blade is provided in the waveguide, and the distance between the peripheral edge of the opening of the power supply port and the outer circumference of the radio wave stirring blade is different depending on the position of the peripheral edge.

Further, the lower end of the opening peripheral portion of the power supply port is located above the rotary mounting table.

The rotation axis of the rotary mounting table and the rotation axis of the radio wave agitating blade intersect at a substantially right angle.

The number of revolutions of the radio wave stirring blade is different from that of the rotary mounting table.

Further, the power supply port is provided with a power supply port cover made of a low-loss dielectric material.

The power supply port cover is made of glass having a low dielectric loss. The outer peripheral end surface of the power feed port cover is covered with a frame body having elasticity with low dielectric loss, and the frame body is configured to project from the power feed port cover toward the heating chamber.

Further, the surface of the power supply port cover has a printing layer printed with low dielectric loss ink.

Further, the radio wave agitating blade is configured to rotate by a drive motor having a play in a rotation shaft portion, and the rotation shaft of the drive motor is fixed so as to be tilted slightly above the horizontal direction.

The waveguide has a radio wave agitation blade chamber for accommodating the radio wave agitation blade, and a convex portion is provided on a part of the radio wave agitation blade chamber wall which is a mounting portion of the drive motor.
A gap is formed between the drive motor and the stirring blade chamber.

Further, the waveguide and the radio wave stirring blade chamber are integrally formed, and the power feeding port is provided in the radio wave stirring blade chamber facing the side wall of the heating chamber.

The power supply port is provided on the rear wall of the heating chamber wall, and the power supply port is larger than the radio wave stirring blade.

Further, the portion of the radio wave agitating blade chamber facing the radio wave agitating blade is painted.

The radio wave agitation blade has a boss made of a low-loss dielectric material, and the boss is provided with a plurality of protrusions. The radio wave agitation blade has a wavelength of about 4 minutes of the high frequency electromagnetic wave. 1. A plurality of mounting holes of 1 or less are provided, and the projecting portion of the boss is inserted into and fixed to the mounting holes.

Further, the radio wave stirring blade and the boss are provided with a protrusion and a small hole for preventing the detachment.

The output shaft of the drive motor is made of a low-loss dielectric material and has a non-circular cross section. The boss has a convex portion and elasticity, and the output shaft of the drive motor is Has a slit substantially parallel to the drive motor, has a through hole having the same shape as the cross section of the output shaft of the drive motor, provides a recess near the tip of the output shaft of the drive motor, and fits the projection of the boss. It was configured.

The radio wave agitating blade has a plurality of stirrer blades having a substantially fan shape.

A second stirrer blade is provided at the tip of the stirrer blade of the radio wave stirring blade.

[0032]

According to the present invention, the electric wave agitating blade is arranged on the rotary mounting table and the side surface of the heating chamber, and the electric power feeding port is provided on the front surface of the electric wave agitating blade. The shape of the electric power feeding port is the tip of the electric wave agitating blade and the edge of the electric power feeding port. High-frequency electromagnetic waves are radiated vertically and horizontally by the radio wave agitating blades by making the shape different from each other, that is, a shape other than a circle such as a square, and by rotating the rotary mounting table, the uniformity of the heated object is dramatically improved. To do.

Even if the rotary mounting table is slightly displaced, it only hits below the power supply port. By making the rotation center of the rotary mounting table and the center line of the rotation center of the radio wave stirring blades substantially coincide with each other, the effect of the radio wave stirring blades on the object to be heated of the rotary mounting table is maximized.

The power supply port cover prevents food scraps and steam from entering the waveguide in the heating chamber, and the object to be heated is not deformed by hitting the radio wave stirring blade.

Further, since the cover is made of glass, the rotating state of the radio wave stirring blade can be visually confirmed.

By covering the outer peripheral end surface of the power supply port cover with an elastic frame, the sealing performance of the power supply port cover is improved, and since the frame body projects from the power supply port cover to the heating chamber side, it is rotatably mounted. The stand does not directly contact the power supply port cover, and even if it hits, the frame serves as a cushioning material to prevent deformation of the power supply port cover.

By printing on the surface of the glass power supply port cover, the rotating state of the radio wave agitating blade can be seen well and the inconvenient part of the radio wave agitating blade can be hidden.

By turning the rotary shaft of the drive motor slightly upward, it is possible to prevent the rotary shaft from facing downward and tilting the radio wave agitating blade attached to the rotary shaft due to backlash of the rotary shaft.

By providing a space between the radio wave stirring blade chamber and the drive motor, it is possible to prevent the heat in the heating chamber from being transferred to the drive motor.

Since the waveguide and the radio wave stirring blade chamber are integrally configured, the heating chamber and the waveguide can be easily configured.

Since the power feed port is larger than the radio wave stirring blade, there is a gap between the power feed port and the radio wave stirring blade, and high frequency electromagnetic waves can be efficiently radiated into the heating chamber through this gap.
Further, the radio wave stirring blade can be easily installed in the heating chamber.

Since the portion of the radio wave agitating blade chamber facing the radio wave agitating blade is coated, the insulation strength between the two is increased and the spark (spark discharge) of the high frequency electromagnetic wave between the two can be prevented. Also, the appearance of the radio wave stirring blade will be improved by the color of the coating.

The boss can be fixed to the boss and the radio wave agitating blade by providing the boss with the radio wave agitating blade and inserting the projecting portion into the mounting hole of the radio wave agitating blade and rotating a little. Further, since the mounting hole has a quarter wavelength or less, the mounting hole can prevent sparks and abnormal heating of the boss due to high frequency electromagnetic waves.

Further, since the small hole of the boss and the projection of the radio wave stirring blade are engaged with each other, they do not come off. The slit on the boss makes the through hole a little larger, so it can be fixed by simply pushing it into the rotary shaft of the drive motor from the heating chamber side, and the boss can be removed from the rotary shaft due to the concave part of the rotary shaft and the convex part of the boss. There is no.

Since the radio wave stirring blade is provided with stirrer blades having a substantially fan shape, the gap between the stirrer blades is also substantially fan-shaped. High-frequency electromagnetic waves are radiated from this gap into the heating chamber. Therefore, since the gap rotates, the high frequency electromagnetic wave is also radiated into the heating chamber while rotating, and the distribution in the heating chamber can be made uniform.

Since the second stirrer blades are provided at the tips of the stirrer blades, the radiation efficiency between the stirrer blades can be increased and at the same time the electric field at the tip of the stirrer blades can be weakened to prevent sparks.

[0047]

Embodiments of the present invention will be described below with reference to the drawings.

The side surface of the heating chamber referred to in the present invention means the wall surface of the heating chamber perpendicular to the surface of the rotary mounting table. In the present invention, the effect is almost the same even if the power supply port is provided on any of the side surfaces, but the case where the power supply port is provided on the rear wall (the surface facing the door), which is the most practical, will be described.

FIG. 1 is a horizontal sectional view of a heating cooker according to the present invention. At the bottom of the heating chamber 1, there is provided a rotary mounting table 2 on which food or the like is placed to rotate, and a high frequency generator 4 is provided at a portion where the heating chamber rear wall 3 is extended in a substantially horizontal direction. 3 is provided with an opening serving as a substantially rectangular power supply port 5. A metallic radio wave stirring blade 6 is provided in the vicinity of the power supply port 5 and is rotated by a drive motor 7. The high-frequency electromagnetic wave emitted from the high-frequency generator 4 is guided to the radio wave stirring blade 6 by the waveguide 8 and stirred, and then radiated from the power supply port 5 into the heating chamber 1. The power supply port 5 is provided with a power supply port cover 9 which is made of, for example, borosilicate glass and has excellent heat resistance with little radio wave loss.
It is prevented from scattering within 0. Reference numeral 11 denotes a frame body made of silicon rubber or the like, which is fitted and fixed around the power supply port cover 9 and is inserted and fixed in the power supply port 5 of the heating chamber rear wall 3 to serve as a sealing member. Further, the power supply port cover 9 also serves as a heat insulation for preventing the heat in the heating chamber 1 from escaping into the radio wave stirring blade chamber 10 when the heater is heated. Further, the waveguide 8 portion and the partition wall 12 portion of the radio wave stirring blade chamber 10 are formed as an integrated diaphragm. Reference numeral 13 is a door that is attached to the front opening of the heating chamber 1 and can be opened and closed.

When heating food in the heating chamber, naturally,
It is necessary to heat the side and height uniformly. The food placed on the rotary mounting table 2 rotates in the intensity of high-frequency electromagnetic waves in the heating chamber, so that the food is uniformly heated in the circumferential direction, but uneven heating easily occurs in the radial direction. High-frequency electromagnetic waves from the high-frequency generator 4 mounted beside the rear part of the heating chamber 1 pass through the waveguide 8 and horizontally from the power supply port 5 at the rear part of the heating chamber 1.
Is supplied to. At this time, the heating pattern of the rotary mounting table 2 is
As a matter of course, the food near the power supply port 5 is heated strongly so that it is heated like hatching. That is, the heating strength becomes weaker as the distance from the power supply port increases. This heating pattern is a heating pattern in which the heating unevenness in the radial direction of the food is eliminated when the rotary mounting table 2 is rotated, but the heating unevenness in the radial direction is not completely eliminated. As the radio wave agitating blade 6 rotates, the patched heating intensity pattern changes (with rotation) as the distribution state of the radiation intensity of the high frequency electromagnetic wave from the power supply port 5 to the heating chamber 1 changes. Therefore, the uneven heating in the radial direction is almost uniform.

FIG. 2 is a vertical sectional view of FIG. 1, in which 14 is an upper heater, and 15 and 16 are lower heaters, respectively, so that the oven can be heated in the heating chamber. Reference numeral 17 denotes a mounting portion of the drive motor 7 according to the present invention, which is the radio wave stirring blade chamber wall 1
A part of 2 is squeezed in a convex shape to prevent the drive motor 7 from coming into close contact with the radio wave stirring blade chamber. When they come into close contact with each other, the temperature of the drive motor 7 rises due to the heat radiated from the inside of the heating chamber 1 at the time of heating the heaters 14, 15 and 16 and the conduction heat provided through the wall 12 of the radio wave agitating blade, and the internal gear and the grease for the gear are increased. It is necessary to make the heat resistant specifications etc., which increases the cost. Further, cooling openings 18 and 19 are provided in the outer box located at the upper and lower portions of the drive motor 7. The wind of natural convection flows like the thick arrow in the figure, so the driving motor 7
Is cooled. Further, since the tip of the fixing screw 20 of the drive motor 7 does not come close to the radio wave stirring blade 6 by providing the throttle portion 17, there is no fear of sparks due to the high frequency electromagnetic wave supplied into the waveguide 8.

With respect to the high frequency electromagnetic waves, the high frequency electromagnetic waves from the horizontal direction are distributed by the radio wave stirring blades 6 in the heating chamber 1 vertically and in a well-balanced manner by the rotation of the radio wave stirring blades 6. Therefore, even under a high load such as warming milk, the upper part is not heated strongly but is heated very uniformly.

FIG. 3 shows a vertical cross-sectional view of FIG.
The rotary mounting table 2 is made of a low-loss dielectric such as pottery, and is capable of mounting an object to be heated (not shown). A turntable motor 47 for rotating the rotary mounting table 2 is arranged under the rotary mounting table 2, and a rotation shaft of the turntable motor 47 is connected to a table 48 for rotating the rotary mounting table 2. .

The waveguide 8 is wide at one end, and the radio wave agitating blade 6 is housed therein to form a radio wave agitating blade chamber 10. Fig. In FIG. 3, a power supply port cover is attached to the power supply port 5, but the description will be given with the cover removed for the sake of explanation.

The power supply port 5 is slightly larger than the radio wave stirring blade 6, and the radio wave stirring blade 6 can be easily attached from the front of the heating chamber. At the same time, in order to efficiently supply the high frequency electromagnetic wave to the heating chamber, the length of the wavelength of the high frequency electromagnetic wave or more is required. Has a size of.

Since the outer circumference of the radio wave stirring blade 6 is smaller than the power supply port 5, a gap is formed between the power supply port 5 and the radio wave stirring blade 6 for passing high frequency electromagnetic waves.

Since the radio wave agitating blade 6 has four substantially fan-shaped stirrer blades 49, the gap between the respective stirrer blades is also substantially fan-shaped.

The power supply port 5 is substantially square, and each corner of the square is slightly arcuate. A high frequency electromagnetic wave from the high frequency generator 4 propagates through the waveguide 8 to the radio wave stirring blade chamber 10.

Here, high frequency electromagnetic waves are radiated in the direction of the arrow into the heating chamber from the substantially fan-shaped gap of the radio wave stirring blade 6. Of course, the outer peripheral portion of the stirrer blade 49 and the power supply port 5
High-frequency electromagnetic waves are also radiated into the heating chamber from the gap portion, but the substantially fan-shaped gap is much larger because the gap is narrow.

The high frequency electromagnetic wave from the substantially fan-shaped gap is radiated in the direction of the arrow in FIG. Here, since the radio wave stirring blade 6 is rotating, the high frequency electromagnetic wave is dispersed in every corner of the heating chamber.

When the power feeding port 5 is circular, since the heating chamber is a rectangular parallelepiped, it is difficult for high frequency electromagnetic waves to reach the corners of the heating chamber. Radiation of the high frequency electromagnetic waves increases, and the high frequency electromagnetic waves reach the corners of the rectangular parallelepiped, and the effect of dispersing the radiation of the radio wave stirring blades 6 over the entire heating chamber increases, and the uniformity of the heated object is increased. improves.

The arc of the corner portion of the substantially square power supply port 5 is
For adjusting the radiation degree of high frequency electromagnetic waves to the corners of the heating chamber, at the same time, when the power supply port cover 9 is made by molding glass of low-loss dielectric material, the corner of the power supply port cover 9 is more arc-shaped. Since the glass easily flows, the power supply port cover 9 is easily molded.

FIG. 4 is an enlarged view of FIG. 2. Reference numeral 21 is a rotary shaft of the drive motor 7, and in order to prevent radio wave leakage from an opening 22 through which the rotary shaft 21 penetrates, ethylene tetrafluoride or the like is used. It is made of heat-resistant resin. A radio wave stirring blade 6 is fixed to the tip of the rotary shaft 21 via a boss 23. Generally, the rotation shaft of the motor has a clearance between it and the bearing (not shown) of the motor so that it does not interfere with the rotation, but the rotation shaft is made of resin that has a large coefficient of thermal expansion and is difficult to obtain molding accuracy. In case of constructing, the clearance is large and the backlash is large. When such a thing is mounted horizontally, since the metallic radio wave stirring blade 6 which is a heavy object is fixed to the tip of the rotary shaft 21, the weight of the rotary shaft 21
The tip of the arrow goes down as represented by θ ° in the figure. Then, the distance a between the lower end of the radio wave agitating blade 6 and the radio wave agitating blade chamber wall 12
Becomes smaller than the distance b in the horizontal state, and the radio wave stirring blade 6
A discharge phenomenon due to high-frequency electromagnetic waves easily occurs at the tip.
Therefore, in the present invention, the mounting portion 17 of the drive motor 7 is provided with an inclination to correct the descending angle θ of the rotary shaft 21 so that the radio wave stirring blade 6 is parallel to the wall 12 of the radio wave stirring blade chamber 10. is doing.

FIG. 5 shows the construction of the waveguide portion and the like of the present invention. Reference numeral 24 denotes the waveguide portion 8 and the radio wave stirring blade chamber 10.
This is an integrated diaphragm made of a metallic material, and is hereinafter referred to as an integrated waveguide. Reference numeral 25 denotes a portion obtained by extending a part of the rear wall 3 of the heating chamber, which forms one surface of the waveguide and is provided with an antenna insertion hole 26 of the high frequency generator 4. The integrated waveguide 24,
The rear wall 3 of the heating chamber is fixed by spot welding or the like to form the waveguide 8 and the radio wave stirring blade chamber 10. In order to make it easier to clean the inside of the heating chamber, those that are coated with fluorine on the inside wall of the heating chamber are
In the state where the waveguide and the rear wall of the heating chamber are spot welded, atomized paint is sprayed from the direction α. The one in which the integrated waveguide 24 and the heating chamber rear wall 3 are fixed to each other is used as the heating chamber upper wall 2
7, the side walls 28, 28 ', the bottom wall 29, and the like are fixed to each other by caulking, spot welding, or the like. At that time, the hatched portions 30 and 31 enter the inside of the integrated waveguide 24, which makes caulking or spot welding impossible,
In the present invention, the integrated waveguide 24 is provided with a hole 32 into which a punch for caulking or a welding electrode can be inserted because it may cause electric wave leakage. The hole 32 has the smallest possible hole so that radio waves do not leak, and has a shape projecting to the outside so that it is not necessary to close it with a radio wave prevention metal fitting from the outside.

FIG. 6 shows a cross section of the main part of the power supply port 5.
The power feeding port cover 9 made of glass having a low dielectric loss is fixedly attached to the power feeding port 5 of the heating chamber 1 by an elastic frame 11 so as to cover the periphery of the end face. It is configured so as to project further toward the heating chamber. The power supply port cover 9 has a concave shape when viewed from the heating chamber 1, and the surface opposite to the heating chamber 1 is covered with a printing layer 40 printed with low dielectric loss ink. This is for the user to confirm the rotation of the radio wave stirring blade 6 during use.

FIG. 7 is a perspective view of the radio wave stirring blade portion of FIG. The radio wave agitating blade 6 has a plurality of mounting holes in which the length of the long side of the mounting hole 41 is approximately ¼ or less of the wavelength of the high frequency electromagnetic wave.

If the length of the long side of the mounting hole 41 is 1/4 or more of the wavelength of the high frequency electromagnetic wave, not only the performance of the radio wave distribution in the heating chamber deteriorates, but also the mounting hole 41 may cause a spark by the high frequency electromagnetic wave. There is.

The radio wave stirring blade 6 and the boss 23 are fixed to each other by inserting the two overhanging portions 42 provided on the boss 23 into the two mounting holes 41 and rotating them by a predetermined angle. When the small hole 43 of the boss 23 is attached, the small hole 43 of the boss 23 does not come in and out of the projection 44 of the radio wave stirring blade 6. Further, the rotation shaft 21 of the drive motor 7 and the boss 23 are fixed to each other by providing the rotation shaft 21 made of a low-loss dielectric material having a substantially oval cross section with a slit 45 formed substantially parallel to the rotation shaft 21. It is fixed by inserting the boss 23 made of the low loss dielectric material.

Reference numeral 51 is a second stirrer blade provided at both end portions of the stirrer blade 49 in a substantially fan-like shape. The second stirrer blade 51 enhances the efficiency of radiation of high frequency electromagnetic waves from the gap between the stirrer blades 49 and the high frequency at the tip of the stirrer blade 49. It plays the role of preventing sparks caused by electromagnetic waves.

FIG. 8 is a sectional view after assembly of FIG. At the mating portion of the rotary shaft 21 and the boss 23, the convex portion 46 is formed on the boss 23.
Are provided so that the bosses 23 do not come off in conformity with the corresponding recesses of the rotary shaft 21.

As described above, according to the present invention, the radio wave agitating blade is arranged on the rotary mounting table and the side surface of the heating chamber, the electric power feeding port is provided on the front surface of the radio wave agitating blade, and the high frequency electromagnetic wave from the side of the power feeding port is provided. The radio wave agitating blades radiate vertically and horizontally into the heating chamber, and the rotation of the rotary mounting table dramatically improves the uniformity of the object to be heated. That is, Cited Example 1 (Japanese Patent Publication No. 60-2)
In 5875), since the power supply port is located in the upper part of the heating chamber, there is non-uniformity in the vertical distribution that the upper part of the object to be heated is strongly heated, and in Reference Example 2 (USP2748239), there is a power supply port in the rear part of the heating chamber. There was a tendency for unevenness to occur in the plane distribution in which the rear part of the heating chamber was heated strongly. Further, in the reference example 3 (USP4136271), there is a drawback that the upper part is heated strongly because the antenna for radiating is on the upper part like the reference example 1.

On the other hand, in the present application, the horizontal distribution and the vertical distribution have good uniformity, so that the frozen food can be thawed without failure, and the upper part is not too hot when milk or the like is heated with a cup or the like.

Further, since the high-frequency electromagnetic wave is directly applied to the object to be heated from the side surface of the heating chamber, even if the size of the heating chamber is slightly distorted, the uniform performance is little affected.

Although the power supply port has been described in the embodiment as having a substantially square shape, it is preferable that the shape of the power supply port is a substantially square shape in view of production. However, the shape is not limited to this, and a shape other than a circular shape is preferable. Of course, any shape is acceptable.

Further, since the lower end surface of the power supply port is located above the rotary mounting table, even when the rotary mounting table is mistakenly inserted deep into the heating chamber, the power supply port cover is not damaged by hitting the frame. .

Since the rotary shaft center insertion portion of the rotary mounting table and the rotary axis of the radio wave stirring blade intersect at a substantially right angle, high-frequency electromagnetic waves are radiated substantially symmetrically with respect to the rotary axis of the rotary mounting table. When the rotary mounting table rotates, the difference in heating between the center of the rotary mounting table and the surroundings is small.

Further, since the rotational speed of the rotary mounting table and the rotational speed of the radio wave agitating blade are different from each other, the radiation state of the high frequency electromagnetic wave from the radio wave agitating blade and the rotary mounting are placed at any position of the rotary mounting table. Since the relative relations of the mounts are different, the vertical and horizontal heating uniformity is the same regardless of the position of the load.

Further, since the inclination of the electric wave stirring blade caused by the looseness of the rotating shaft of the drive motor is corrected, the discharge phenomenon in the radial direction of the electric wave stirring blade can be suppressed, and
It is also possible to prevent deterioration of the stirring performance due to the inclination of the radio wave stirring blade.

Furthermore, since the structure is such that the radio wave stirring blade chamber, the waveguide, etc. are provided on the side surface of the heating chamber, even in the high frequency heating device with a heater, a high frequency heating device that provides uniform radio wave heating is not restricted by the heater configuration. This can be realized, and by devising the method of attaching the power supply port cover, frame, drive motor, etc., it is possible to prevent cost increase due to heat resistance specifications of parts due to heat when heating the heater.

Furthermore, the waveguide and the radio wave agitating blade chamber are formed as an integral diaphragm, and the high-frequency generator mounting portion has a simple structure in which only a part of the rear wall of the heating chamber is extended. Since the pipe is provided with caulking, punches for spot welding, and holes into which the electrode rods are inserted, the heating chamber can be easily assembled, and the whole structure can be simply and inexpensively constructed.

Further, by enlarging the power feeding port to the same size or larger than the size of the radio wave agitating blade, the radio wave agitating blade can be attached to the drive motor from the side of the heating chamber. Will be easier. If it cannot be installed from the heating chamber side, the drive motor and the radio wave agitating blade are fixed to the integrated waveguide in advance, and then attached to the rear wall of the heating chamber with screws, or the integrated waveguide is driven. Since the motor mounting part has a lid configuration that can be removed together with the radio wave agitation blade, when fixing with screws, there is a problem of radio wave leakage unless they are fixed with a pitch of 20 mm to 30 mm. Many screws must be fixed, resulting in poor appearance and assembly.

Generally, in the case of a high-frequency heating device with a heater, a heat-resistant coating such as fluorine coating is often applied to the inside of the heating chamber wall in order to provide easy cleaning of the heating chamber. By making the mouth larger than the radio wave agitating blade, for example, by spot welding the integrated waveguide and the rear wall of the heating chamber and then painting, even if spray painting, the paint will not come out from the power feeding port. Then, since the wall of the radio wave agitating blade chamber facing the radio wave agitating blade is painted, an insulating film is formed and the effect of suppressing the spark of the radio wave agitating blade is exerted.

Furthermore, since the power supply port of the heating chamber is protected by the strong glass power supply port cover, it is possible to prevent the deformation of the radio wave stirring blade. Also, the power supply port cover is covered with an elastic frame so as to project from the power supply port cover, and the power supply port cover has a concave shape and is fixedly attached to the power supply port of the heating chamber so that it is mounted by rotation. Even if you accidentally hit the table, it will be protected by the frame and absorb the shock. Further, since the ink with low dielectric loss is printed on the surface of the power supply port cover, it can be immediately found when the user stops the radio wave stirring blade due to a failure.

The power supply port cover is not limited to glass, but ceramics,
Needless to say, the same effect can be obtained by using porcelain.

Further, since it is attached around the end face of the power supply port cover via the elastic frame, it is possible to absorb the dimensional variation of the glass and perform stable work.

Since the power feed port cover is fixedly attached to the power feed port of the heating chamber through the frame, it has a sealing property and prevents food dust and steam from entering and insulation deterioration due to heat and steam of the drive motor and the like. It also prevents the occurrence of rust.

Further, the radio wave stirring blade is provided with a plurality of mounting holes each having a wavelength of about a quarter or less of the wavelength of the high frequency electromagnetic wave, and a plurality of overhanging portions provided on the boss are inserted and fixed. Does not deteriorate and there is no spark due to high frequency electromagnetic waves in this mounting hole. In addition, the radio wave stirring blade and the boss can be easily attached, and the number of parts is small, so that it is inexpensive and easy to assemble.

When fixing the output shaft of the driving motor to the boss, a slit is provided in the boss and the boss is attached to the rotary shaft by the elastic force of the boss, so that the boss can be easily attached from the direction of the rotary shaft.

Since the convex portion 46 of the boss is aligned with the concave portion of the rotary shaft, no stress is applied to the boss. Therefore, even if the temperature in the heating chamber is raised by the heater, the boss does not deform and the boss does not fall out.

As described above, according to the present invention, the rotary mounting table is provided on the bottom surface of the heating chamber, the power feeding port is arranged on the side of the heating chamber, and the high frequency electromagnetic wave is supplied from the side of the power feeding port. By providing a radio wave stirring blade in the vicinity, a uniform heating state can be obtained for heating various foods. For example, when warming milk, the difference in temperature rise between the upper part and the lower part is small, and the difference in heating between the center and the periphery is small even when heating flat food. In addition, even when thawing frozen foods, it can be thawed uniformly, but especially at the vertices and edges because it is abnormally heated and is not boiled
Can be thawed without unevenness.

[0091]

EFFECTS OF THE INVENTION Since the homogeneity of the inside of the container has been dramatically improved, frozen foods such as meat and fish, which are required to have homogeneity performance, can be thawed uniformly to room temperature without being boiled or frozen. Also, when heating milk etc., the upper part of the container does not become hot. Also, there is no difference in the finished product because the distribution is good regardless of whether the object to be heated is placed at the center of the rotary mounting table or around it. Moreover, since the power supply port is approximately square, high-frequency electromagnetic waves reach the upper and lower corners of the heating chamber.

Even if the rotary mounting table is slightly displaced, it does not hit the power supply port portion, so that the radio wave stirring blade is not damaged or deformed, so that the distribution performance is not easily deteriorated.

Since the extension lines of the rotation center of the rotary mounting table and the rotation center of the radio wave stirring blade coincide with each other, the stirring effect of the radio wave stirring blade is greater than that of the rotary mounting table.

The object to be heated does not hit the radio wave stirring blade due to the power supply port cover, and the food waste adheres to the radio wave stirring blade,
It is extremely safe and reliable because it does not burn when heated.

Since the power supply port cover is made of glass, the rotation state of the radio wave agitating blade can be confirmed well, and there is a visual effect, and a failure can easily be found when stopped, and failure of heating such as cooking can be prevented.

The frame body prevents the object to be heated or the rotary mounting table from directly hitting the power feed port cover, and even if it hits, the impact of the power feed port cover can be weakened.

By printing a part of the power supply port cover, the visual effect can be improved and the inconvenient part of the radio wave agitation blade can be hidden so that the appearance is improved and the commercial value is improved.

By mounting the drive motor slightly upward, the radio wave agitating blades do not tilt so that the uniform distribution performance is stable and the distance between the radio wave agitating blades and the radio wave agitating blade chamber wall is the same vertically, so sparking etc. Can be prevented and reliability is increased.

Since it is not necessary to improve the heat resistance of the drive motor due to the gap between the radio wave stirring blade chamber and the drive motor, inexpensive bearings and grease can be used for the drive motor, and the cost does not increase.

Assembling the heating chamber and the waveguide is simple. Since the power supply port is provided on the rear wall of the heating chamber and the power supply port is larger than the radio wave stirring blade, the radiation efficiency is good, and when the radio wave stirring blade is fixed to the drive motor, it can be easily assembled from the front surface of the heating chamber.

Since the wall of the radio wave agitating blade chamber is coated, the insulation performance from the radio wave agitating blade is improved, the spark between the two can be prevented, and the reliability can be secured even when the heating chamber becomes empty. The appearance of the radio wave stirring blade is also good.

The boss and the radio wave agitating blade can be easily fixed to each other, and the mounting hole for fixing the boss is one quarter of the wavelength of the high frequency electromagnetic wave.
Since it is below, sparks at this part are prevented and the boss does not melt or burn, so it is highly reliable.

The boss and the radio wave stirring blade do not come off.
It can be easily assembled because it can be easily fixed to the boss and the rotary shaft of the drive motor.

Since the radio wave agitating blade has a plurality of substantially fan-shaped stirrer blades, high-frequency electromagnetic waves are radiated from the fan-shaped gap while rotating toward the heating chamber, so that the distribution in the heating chamber becomes uniform and thawing occurs. Even if it is boiled or left as ice, it can be uniformly thawed to room temperature. Also, when heating a tall heated object such as milk, the temperature difference between the upper and lower sides is small.

Since the second stirrer blade is provided at the tip of the stirrer blade, the high-frequency electromagnetic wave can be efficiently radiated from the fan-shaped gap, and the output loss is small. Further, it is possible to prevent sparks due to abnormal electric field concentration at the tips of the stirrer blades.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of a heating cooker according to an embodiment of the present invention.

FIG. 2 is a side sectional view of the heating cooker.

FIG. 3 is a front vertical sectional view of the heating cooker.

FIG. 4 is a side view showing a drive motor mounting portion of the heating cooker.

FIG. 5 is a perspective view of a waveguide and a heating chamber rear wall of the heating cooker.

FIG. 6 is a perspective view of a power supply port cover of the heating cooker.

FIG. 7 is a perspective view of a radio wave stirring blade of the heating cooker.

FIG. 8 is a sectional view of the electric wave stirring blade of the cooking device after assembly.

FIG. 9 is a sectional view of a conventional heating cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating chamber 2 Rotating mounting table 3 Rear wall 4 High frequency generator 5 Power supply port 6 Radio wave stirring blade 7 Drive motor 8 Waveguide 9 Power supply port cover 10 Radio wave stirring blade chamber 11 Frame 12 Radio wave stirring blade chamber wall 21 Rotating shaft 22 Opening 23 Boss 40 Printed layer 41 Mounting hole 42 Overhanging part 43 Small hole 44 Protrusion 45 Slit 46 Convex part 49 Stirrer blade 51 Second stirrer blade

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese Patent Application No. 4-140238 (32) Priority date Hei 4 (1992) June 1 (33) Country of priority claim Japan (JP) (31) Priority Claim No. Japanese Patent Application No. 4-140239 (32) Priority Date No. 4 (1992) June 1 (33) Country of priority claim Japan (JP) (31) Priority claim number Japanese Patent Application No. 4-164484 (32) Priority Hihei 4 (1992) June 23 (33) Priority claiming country Japan (JP) (72) Inventor Mitsuo Akiyoshi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (18)

[Claims] 1. A heating chamber for heating an object to be heated in the body,
A high-frequency generator that generates high-frequency electromagnetic waves, a waveguide that guides the high-frequency electromagnetic waves of the high-frequency generator to the heating chamber, a rotary mounting table that supports the object to be heated and rotates together with the object, and the heating chamber. A radio wave agitating blade for agitating the high frequency electromagnetic wave, the power feeding port of the waveguide is disposed on the side surface of the heating chamber, and the radio wave agitating blade is provided inside the waveguide so as to face the power feeding port. A heating cooker having a shape in which the distance between the peripheral edge of the mouth opening and the outer periphery of the radio wave stirring blade varies depending on the position of the peripheral edge. 2. The lower end of the opening peripheral portion of the power supply port is
The cooking device according to claim 1, wherein the heating cooker is positioned above the rotary mounting table. 3. The heating cooker according to claim 1, wherein the rotation axis of the rotary mounting table and the rotation axis of the radio wave agitating blade intersect at a substantially right angle. 4. The heating cooker according to claim 1, wherein the electric wave agitating blade is rotated at a rotational speed different from that of the rotary mounting table. 5. The heating cooker according to claim 1, wherein the power feeding port is provided with a power feeding port cover made of a low-loss dielectric. 6. The cooking device according to claim 5, wherein the power supply port cover is made of glass having a low dielectric loss. 7. The heating according to claim 5, wherein the outer peripheral end surface of the power feeding port cover is covered with a frame body having elasticity with a low dielectric loss, and the frame body projects from the power feeding port cover toward the heating chamber. Cooking device. 8. The cooking device according to claim 5, further comprising a printing layer printed with low dielectric loss ink on the surface of the power supply port cover. 9. The radio wave stirring blade is configured to rotate by a drive motor having a play in a rotation shaft portion, and the rotation shaft of the drive motor is fixed so as to incline slightly above the horizontal direction. Cooking device. 10. The wave guide has a radio wave agitation blade chamber for accommodating the radio wave agitation blade, and a projection is provided on a part of a wall of the radio wave agitation blade chamber to be a mounting portion of the drive motor. The heating cooker according to claim 9, wherein a gap is formed between the drive motor and the stirring blade chamber. 11. The heating cooker according to claim 9, wherein the waveguide and the radio wave agitating blade chamber are integrally configured, and the electric power feeding port is provided in the radio wave agitating blade chamber facing the heating chamber side wall. 12. The heating cooker according to claim 9, wherein the power supply port is provided on a rear wall of the heating chamber wall, and the power supply port is larger than the radio wave stirring blade. 13. The heating cooker according to claim 9, wherein coating is applied to a portion of the radio wave agitation blade chamber facing the radio wave agitation blade. 14. The radio wave agitation blade has a boss made of a low-loss dielectric, the boss is provided with a plurality of overhangs, and the radio wave agitation blade has a wavelength of about 4 minutes of the high frequency electromagnetic wave. 10. The heating cooker according to claim 9, wherein a plurality of mounting holes of 1 or less are provided, and the projecting portion of the boss is inserted into and fixed to the mounting holes. 15. The cooking device according to claim 14, wherein the radio wave agitating blade and the boss are provided with a protrusion and a small hole for preventing separation. 16. The output shaft of the drive motor is made of a low-loss dielectric and has a non-circular cross section, and the boss has a convex portion and elasticity. Has a slit substantially parallel to the drive motor, has a through hole having the same shape as the cross section of the output shaft of the drive motor, provides a recess near the tip of the output shaft of the drive motor, and fits the projection of the boss. The cooking device according to claim 14, which is configured. 17. The cooking device according to claim 9, wherein the radio wave stirring blade has a plurality of stirrer blades having a substantially fan shape. 18. The cooking device according to claim 17, wherein a second stirrer blade is provided at the tip of the stirrer blade of the radio wave stirring blade.