JPS6017831Y2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotary mounting table for a heated object in a high-frequency heating device.

Conventionally, in order to heat the heated object more uniformly when heating the heated object using high frequency waves, a rotating mounting table for the heated object has been provided.

This is an attempt to irradiate the object to be heated with high frequency waves relatively evenly by rotating the object to correct the unevenness of the high frequency waves irradiated into the heating chamber.

There are two ways to drive this heated object rotation mounting table: one uses a motor as the power source, a rotating shaft is exposed at the bottom of the heating chamber, and the heated object rotation mounting table is attached to this rotating shaft, and the other has a motor installed at the outside bottom of the heating chamber. There is a method in which a rotating body connected to a heated object and a rotating mounting table for the heated object are provided corresponding to the bottom surface of the heating chamber, and the rotational force is transmitted by the magnetic coupling force of the magnets attached to the rotating body and the rotating mounting table for the heated object. .

At this time, it is very troublesome for the user to clean the heating chamber in the former case because the rotating shaft, rollers for supporting the rotating mounting table, etc. are directly exposed at the bottom of the heating chamber.

Also, in terms of safety, if moisture is spilled inside the heating chamber, the moisture will drip outside the heating chamber at the bottom of the heating chamber and the rotating shaft seal, which will adversely affect the motor charging parts installed at the outside bottom of the heating chamber and cause electrical leakage. This is highly unreliable.

However, the latter does not have any of the above drawbacks and is a very reliable structure that is easy to clean and completely non-hazardous.

However, when magnetic coupling force is used for power transmission, there is a limit to the attractive force of the magnet, and there are various design constraints.

In other words, in order to reduce the force required for rotation, the support structure of the rotating mounting table must have rolling friction to minimize the resistance generated during rotation, and the supporting structure of the rotating mounting table has a very small coefficient of friction. In addition to having to use a resin material, a material with high heat resistance and low loss due to high frequencies had to be used, which was very restrictive.

However, recently, some models have been equipped with heaters, making the thermal conditions extremely severe, while the usage conditions have been limited when using magnetic coupling force, which is naturally easy to use and highly safe, for power transmission.

Therefore, the present invention is capable of providing a structure that is not restricted by usage conditions, exhibits stable performance using inexpensive materials, and is easy to use.Hereinafter, one embodiment of the present invention will be described with reference to drawings. .

FIG. 1 is a front view of a high-frequency heating device with a heater equipped with a table for placing objects to be heated. Heaters 2 are installed in the upper and lower parts of the heating chamber 1, and the structure of the rotating table is similar to that of the second
As shown in the figure, a rotating mounting table 3 and a drive motor 4 are provided at the outer bottom of the heating chamber 1, and a hole 6 is provided at the bottom of the heating chamber for inserting the rotating shaft 5 of the motor 4 into the heating chamber. A gear 7 for transmitting driving force to the rotary mounting table 3 is provided on the shaft.

At this time, since the rotating mounting table is unstable when the object to be heated is placed on it only by the gear 7, a supporting roller 8 is provided via a mounting fitting 9.

In this type of system, if the object to be heated is a liquid such as coffee, milk, or alcohol, if the object is inadvertently spilled during heating or when the user is putting it in and taking it out, it will accumulate at the bottom of the heating chamber and cause the opening of the motor rotation shaft 5. Despite the presence of the sealing material 10 from the section 6, there is a high possibility that moisture will drip onto the motor rotation bearing section and the charging section, causing damage such as electrical leakage and motor rotation failure.

Furthermore, the ease of cleaning, which is a major advantage of the high-frequency heating device, is greatly impaired because the roller 8, mounting bracket 9, motor rotating shaft 5, gear 7, etc. protrude from the bottom of the heating chamber.

However, on the other hand, there are devices that retain the advantages of high-frequency heating devices and are equipped with a driving force transmission structure using magnetic coupling force in order to provide a rotating mounting table to reduce uneven heating of the heated object.

FIG. 3 is a front view of the same, and as shown in FIG. 4, the driving force transmission structure is as shown in FIG.
A rotating body 13 is provided, and this rotating body 13 is rotated by the rotational force of a motor via a rubber belt 14 around a shaft 15 provided at the outside bottom of the heating chamber. The rotary mounting table 11 rotates while being attracted to the rotary body 13 due to the attraction force between the magnets provided on the mounting table 11.

However, the attractive force between the magnets is limited by the distance between the two magnets and the magnetic force of the magnets themselves, and the design is extremely restricted. At this time, when a load is applied to the roller 8 and the frictional resistance rapidly increases and becomes larger than the magnetic coupling force, only the rotating body 13 rotates idly and the rotating mounting table 11 stops.

Therefore, it is necessary to reduce the frictional resistance due to the load, so by changing the rotation of the roller from sliding friction to rolling friction, the frictional resistance during rotation is greatly reduced.

However, in this structure, since the roller 8 must be rotated and also revolved, a roller position regulating member 17 is required that always holds the roller at a constant pitch and is rotatable, that is, determines the orbit of the revolution of the roller.

At this time, since the heating chamber 1, the rotary mounting table 11, and the cover 18 for housing the magnet are made of metal bodies, each metal body is designed to maintain an appropriate gap.

In other words, if metal objects come into contact with each other when irradiated with high-frequency waves, or the gap is too small, the high-frequency electric field will concentrate.
This is because there is a danger of sparks, etc.

Therefore, conventionally, the roller position regulating member 17 and the roller 8 are made of a resin material to maintain an appropriate gap between the metal bodies.

At this time, the roller position regulating member 17 and the roller 8 are
Since it is exposed to high frequency waves in the heating chamber, it is required to have low high frequency loss and high heat resistance.

In other words, some resin materials absorb radio waves easily while others do not. When absorbing radio waves, the material itself generates heat, and when the temperature exceeds the heat resistance of the material, it changes and melts.

The types of materials that have low high frequency loss and high temperature resistance as described above are limited in variety and are very expensive, making selection and design of materials very difficult.

However, recently, some have been equipped with heaters to compensate for one of the drawbacks of high-frequency heating, which is that charring is invisible and bread and kutskii cannot be baked.

When this is combined with a rotating mounting table that transmits the driving force through magnetic coupling, the temperature of the resin material mentioned above becomes extremely high (approximately 250 to 300°C). It fell into an unusable state.

Therefore, in the case of the above-mentioned configuration, the heater 19 is installed as shown in FIG.
is provided above the rotating mounting table 11, and a heat shield plate 20 is provided so that the rotating mounting table mechanism does not receive the heat of the heater 19 directly.

With this method, the resin material of the rotary mounting table mechanism is hardly affected by the heat of the heater and can provide stable performance.

However, this method has the disadvantage that, as shown in FIG. 6, a heater unit consisting of a heater 19 and a heat shield plate 20 must be inserted into the oven during cooking, and must be removed during high-frequency heating.

In other words, even though the mechanism was designed for ease of use, when a heater is installed, the heater unit has to be taken out and put in, making it inconvenient to use.Additionally, the addition of the heat shield plate 20 increases the number of parts. The cost is forced to increase, and the user bears a considerable burden.

Therefore, in the present invention, the roller position regulating member 17 and roller 8 are installed as shown in Fig. 7 with a structure that makes maximum use of the conventional advantages of ease of use and eliminates the above-mentioned disadvantages even when the heater is installed. The heater 19 is installed inside the rotary mounting table rather than the magnet 12, and the rotary mounting table is reduced by the space of the roller outside the magnet, and the heater 19 is placed on the outer periphery of the rotary mounting table. By setting the distance between the plastic parts and the resin parts, the structure is such that it is not easily affected by the heat of the heater.

However, at this time, when placing the object to be heated on the rotating mounting table, the 8th
If the object to be heated 21 is placed on the rotating mounting table 11 at a position shifted from the center as shown in the figure, the object to be heated 21 will be placed on the outer periphery of the supporting roller 8, resulting in a very unstable condition. If the magnetic cover 18 is tilted, there is a high risk that the magnet cover 18 will hit the bottom surface of the heating chamber and cause sparks or that the object to be heated will fall over, which is very inconvenient for the user.

At this time, it would be better to reduce the size of the magnet 12 and increase the mounting pitch force of the roller 8, but when considering the magnetic coupling force between the magnets, the shape and size of the magnet may be reduced unnecessarily. It is not possible.

In other words, the magnetic flux density of the magnet has a limit depending on the material, and in order to obtain the required length of magnetic coupling torque, the installation pitch of the magnet is P1.
The only option is to increase 2 or increase the length in the direction perpendicular to the direction of rotation of the magnet.

There is also a method of increasing 11, but this is not very effective in increasing the torque during magnetic coupling.

Therefore, in this invention, as shown in the right part of Figure 9, magnet 11 is replaced by 2.
Double it! By increasing 2 to 172 times, the volume remains the same, but the position P1 of the inner end face of the magnet can be increased to P2, and the mounting pitch of the rollers 8 can be increased.

In addition, by reducing the 12 dimensions that are important for magnetic coupling torque, 1 is doubled in size and magnetized into multiple poles, so not only does the magnetic coupling torque not become small, but the mounting pitch of each magnet is □<P2.

Moreover, since the volume of the magnets does not change, the cost is exactly the same, as shown in Figure 10. It also includes elements that are larger than those in A.

In this way, in the present invention, when the rotary mounting table supporting roller is provided inside the magnet, the magnetic coupling torque can be greatly improved without increasing the cost. This allows us to provide a very effective structure that can exhibit stable performance even under uneven loads on the heated object, giving users peace of mind when using a heater that is easy to use and highly reliable. A high frequency heating device can be used.

[Brief explanation of drawings]

Figure 1 is a front view of a high-frequency heating device equipped with a heater equipped with a rotary mounting table, Figure 2 is a sectional view of the rotary mounting table drive section of Figure 1, and Figure 3 is a circuit diagram that uses magnetic coupling to transmit driving force. A front view of the high-frequency heating device with a heater equipped with a transfer table, Fig. 4 is a cross-sectional view of the rotating mounting table drive part of Fig. 3, and Fig. 5 is a diagram of the high-frequency heating device of Fig. 4 with a lower heater attached. cross section,
Fig. 6° is an external view of the lower heater unit, Fig. 7 is a diagram showing an embodiment of the present invention in which the roller is installed inside the magnet, and Fig. 8 is a diagram showing the relationship between the roller and the magnet. Figure 9 is a cross-sectional view when an unbalanced load is applied to the inside, Figure 9 is a diagram showing the relationship when the magnet of the present invention is magnetized into multiple poles, and Figure 10 is a diagram showing the relationship when magnetized with multiple poles. A diagram explaining the direction and polarity of magnetic lines of force,
FIG. 11 is a cross-sectional view of the main parts of a high-frequency heating device showing an embodiment of the present invention. Death...Roller 9...Mounting bracket, 11
... Rotating transfer table, 12 ... Magnet, 1
3...Rotating body, 18...Jisaku cover.

Claims (1)

[Scope of utility model registration request] A food placement table rotatably installed on the bottom of the heating chamber, an electric heater placed on the outer periphery of the food placement table, a rotating body connected to a motor via a deceleration means for rotationally driving the food placement table, and A plurality of driving magnets provided on the body and a means for magnetically coupling to the magnets provided on the food mounting table are provided, and the food is placed on the inner side of the plurality of driving magnets provided on the food mounting table. A high-frequency heating device is provided with a roller for supporting a table, and the magnet is magnetized with multiple poles.