JPS6158951B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a high frequency heating device.

When heating an object to be heated using a high-frequency heating device, when the object to be heated is not located within the heating coil, power is wasted in the heating coil. Therefore, it is conceivable to control the high frequency generator using a mechanical switch element or a semiconductor switch element so that power is supplied to the coil only when the object to be heated is located within the coil, but the former The latter switch element is not practical because it easily deteriorates over time, and the latter switch element is expensive and requires a complicated control circuit.

An object of the present invention is to provide a high-frequency generator that solves these problems, and is characterized in that an impeder core that has the effect of increasing the impedance of the coil can be inserted and removed within the heating coil. It is in the configuration arranged.

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

When assembling a can 5 as shown in FIG. 2 using the can body 1, top plate 2, and base plate 3 shown in FIG.
Adhesive 4 is applied to the surfaces of the upper and lower flanges 1a and 1b of the can body 1 and the inner peripheries of the top plate 2 and bottom plate 3, respectively, and they are joined together, and then a seaming machine (not shown) is applied. As shown in FIG.
Then, in order to increase the strength and airtightness of the can 5, the adhesive 4 in the seamed portions 5a and 5b is cured using a high frequency heating device.

FIG. 4 conceptually shows an embodiment of the high-frequency heating apparatus of the present invention, which is applied when heat-treating the seams 5a and 5b of the can 5.

This device includes a stocker section _A1 for storing the cans 5 to be heat-treated, a top heating section A2 for heating the top plate seaming section 5a of the can 5, and a top plate seaming section _A2 for heating the top plate seaming section 5a of the can 5. It is composed of a first heating line A having a base plate heating section _A3 that heats the section 5b, and a second heating line A' having the same configuration as the heating line A.

The top plate heating section A ₂ of the first heating line A includes a table part 11a that is raised and lowered by a cylinder 11, and a table part 11a that is raised and lowered by a cylinder 11.
A heating coil 12 is positioned at an appropriate distance upward from a, and an impeder core 13 (described later) is attached to the tip thereof, and the impeder core is held downward by a spring 14 so that the impeder core is always positioned within the coil 12. It consists of a support rod 15 energized.

The base plate heating section A ₃ of the heating line A has a heating coil 16 and an impeder core 17 (to be described later) attached to the tip thereof, and is moved upwardly by a spring 18 so that the core is always positioned inside the coil 16. It is composed of a biased support rod 19, a pressing plate 20 located an appropriate distance above the impeder core 17, and a cylinder 21 that supports the plate 20 so as to be movable up and down.

On the other hand, the stocker section of the second heating line A'
A′ ₁ , top plate heating section A′ ₂ and bottom plate heating section A′ ₃ are as follows:
Each of them has the same configuration as each part A ₁ , A ₂ and A ₃ of the first heating line A, and each of these components is given a symbol with a dot added to the symbol of each element of the above line A. .

22 and 23 each indicate a high frequency generator, and the device 22 includes heating coils 12 and 1 connected in parallel to each other.
2' is connected through a transformer 24, while the device 23
are heating coils 16, 16' connected in parallel with each other.
are connected via a transformer 25.

Next, the impeder cores 13, 13' and 17, 17' will be explained. These impeder cores each have a ferrite core 13b, a
13b', 17b, 17b', and the lower surface of cases 13a, 13a' and case 1
Femit plates 13c, 13c' and 17c, 17c' made of a heat-resistant material such as asbestos are attached to the upper surfaces of 7a, 17a', respectively.

In the high frequency heating device shown in the above embodiment,
Cylinders 11 and 21 of the first heating line A;
Cylinders 11' and 21' of second heating line A'
are controlled by a control means (not shown) so that they operate in opposite directions. Further, the cans 5 located in the stocker section _A1 of the first heating line A and the cans 5 to be treated stored in the stocker section _A'1 of the second heating line A' are stored in the respective cylinders 11, 21, The heating parts A ₂ and A' 2 and the base plate heating parts A ₃ and A' ₃ are sequentially transported by a transport means ₍ not shown) in synchronization with the operations of the heating parts 11' and 21'. Of course, in that case, the loading operations in each heating line A, A' are carried out alternately.

As shown in FIG. 4, the first heating line A
Both cylinders 11 and 21 do not press,
Cylinders 11' and 21' of second heating line A'
Consider the case where both are operating under pressure. In such a case, impeder cores 13 and 17 are located in each coil 12 and 16 of the first heating line A, and impeder core 13' of the second heating line A'
is pushed upward by the upper end surface of the can 5 placed on the stand 11a', and further heated to the heating part A' ₃
The impeder core 17' is pressed down by the lower end surface of the can 5 placed above it. The top plate heating section 5a and bottom plate heating section 5b of each can 5 are inserted into the coils 12' and 16' of the heating line A', respectively.

FIG. 5 shows an electrical connection diagram in such a state. In the figure, the output voltages of the transformers 24 and 25 are each E, the output current is i ₀ , the inductance of the coils 12 and 16 is each L ₁ , the inductance of the coils 12' and 16' is each L 2 , and the inductance of the coils 12 and 16 is each L ₂ . Assuming that each resistance component is r ₁ and that of the coils 12' and 16' is each r ₂ , the circuit connected to each high frequency generator 22 and 23 in the same figure can be equivalently represented as shown in FIG.

Therefore, if the currents flowing through the above resistance components r ₁ and r ₂ are respectively i ₁ and i ₂ , these currents are respectively However, X _L1 is the reactance of coils 12 and 16 However, X _L2 is expressed as the reactance of the coils 12' and 16', and therefore the powers P ₁ and P ₂ consumed by the above resistance components r ₁ and r ₂ are as follows: becomes.

Therefore, the coils 12 and 1 in the heating line A in which the impeder cores 13 and 17 are inserted
Each inductance L ₁ of No. 6 is considerably larger than that when the core is air-core. On the other hand, each inductance L ₂ of coils 12' and 16' in heating line A'
Although it is slightly lower than when the core is air-core due to the effect of the winding portions 5a and 5b located inside these coils, it maintains the value when the core is air-core. Therefore, the inductance of the coils 12 and 16
Assuming that L ₁ is 10 times the value when the core is empty, X _L1 ≒ 10X _L2 (3). Further, the resistance components r ₁ and r ₂ include the resistance component of the coil itself and the resistance component obtained by converting the power consumption of the heated body (sealed parts 5a, 5b) as the resistance on the coil side. Under the condition shown in the figure, the following relationship holds: r ₂ ≒ 3r ₁ ......(4).

Substituting the above equation (3) into equation (1) and the above equation (4) into equation (2), we get is obtained, so the ratio of each power is Since _the Q of each of ^the heating coils in one turn is around 30 _, r ² ₁ ^<< It can be expressed as P ₁ :P ₂ =1/300:1. Therefore, if the output power of the high frequency generators 22 and 23 is 10KW, the power P ₁ supplied to the coils 12 and 16 is P ₁ ≒10000W×1/300≒33W, and the power P 1 supplied to the coils 12' and 16' is Power supplied P ₂
becomes P ₂ ≒10000W×300/301≒9967W.

That is, in the operating state of the device shown in FIG. 4, most of the output power of the high frequency generators 22 and 23 is supplied to the coils 12' and 16', and only a small amount of power is supplied to the coils 12 and 16. .
In this way, the impeder cores 13, 17
functions as a type of non-contact switch element that suppresses power supply to the coils 12 and 16.

In the second heating line A', when the top plate fastening part 5a and the bottom plate fastening part 5b of each can 5 are heated for a certain period of time, the cylinders 11' and 21' of the line A' descend and rise, respectively. , At the same time, the cylinders 11 and 21 of the first heating line A rise and fall, respectively. As a result, impeder cores 13' and 17' are inserted into the coils 12' and 16' of the second heating line, respectively, contrary to the above, so that most of the electric power is supplied to the coils 12' and 16'. It will no longer be done. On the other hand, the coil 12 of the first heating line A
The top plate seaming part 5a and the bottom plate seaming part 5b of each can 5 are respectively located in the can 16 and are heated.

During the heat treatment in the first heating line A, the can 5 located in the top heating section A' ₂ of the second heating line A' is transferred to the bottom heating section A' ₃ by a conveying means (not shown). At the same time, a new can 5 to be processed is carried from the stocker section _A'1 to the top heating section _A'2 .

In this way, the top plate and bottom plate seaming portion 5 of the cans 5 to be treated stored in the stocker portions A ₁ and A′ ₁ are
a, 5b are sequentially subjected to high frequency heat treatment in each line A, A', and in this embodiment, high frequency generators 22, 23 with an output of 10 KW are used.
Furthermore, assuming the machine tact of each line A and A' to be 1 second, it was possible to process 60 5-gallon cans per minute.

In the above embodiment, two heating coils are connected to each of the two high-frequency generators, but as shown in FIG.
Transformers 27 and 28 are connected in parallel to each other, and the coils 12 and 12' are connected in parallel to the output terminal of the transformer 27, and the heating coil 1 is connected to the transformer 28 in parallel to each other.
6 and 16' may be connected in parallel. In this case, the output power of the high frequency generator 26 is the same as that of the high frequency generator 2.
It is set to about twice that of 2 and 23.

As described above, in the high frequency generator according to the present invention, the impeder core is removably disposed within the heating coil, and the core suppresses the power consumption of the coil during non-heating. Therefore, it can be constructed more simply and inexpensively than conventional devices of this type in which the above-mentioned power consumption is suppressed by intermittent operation of the power supply using a mechanical switch element or a semiconductor switch element. , and the above-mentioned drawbacks of each of the above switch elements can be eliminated. In particular, the device of the present invention is suitable for use when power is alternately supplied to a large number of heating coils as shown in the embodiments.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing how the top plate and bottom plate are bonded to the can body, Fig. 2 is a perspective view of the assembled can, and Fig. 3 is an enlarged cross-sectional view of the top plate and bottom plate seaming part. FIG. 4 is a conceptual diagram showing an embodiment of the high-frequency heating device according to the present invention for high-frequency heating the top plate seam portion and the bottom plate seam portion of a can, and FIG. 5 is a conceptual diagram of the device shown in FIG. 4. 6 is an equivalent circuit diagram of the electrical connection diagram shown in FIG. 5, and FIG. 7 is an electrical connection diagram when one high frequency generator is used. 1... Can body, 2... Top plate, 3... Base plate, 4... Adhesive,
5...Can, 5a...Top plate seaming part, 5b...Bottom plate seaming part,
11, 11', 21, 21'...Cylinder, 11a,
11a'... Base part, 12, 12', 16, 16'... Heating coil, 13, 13', 17, 17'... Impeder core, 13a, 13a', 17a, 17a'... Ferrite, 14, 14', 18, 18'...Spring, 1
5, 15', 19, 19'...Support rod, 22, 23,
26...High frequency generator, 24, 25, 27, 28
...Transformer, A...First heating line _{, A'...Second heating line, A1, A'1...Stocker section, A2, A'2 ... Top plate} heating section, _A3 , _A'3 ...Bottom plate heating Department.

Claims (1)

[Scope of Claims] 1. An impeder core that has the effect of considerably increasing the inductance of the coil compared to an air core is removably arranged in a heating coil connected to a high frequency generator, and the heating coil A high-frequency heating device characterized in that the impeder core is configured to escape from the coil when a heated object is inserted therein. 2. The high-frequency heating device according to claim 1, wherein the impeder core is made of ferrite. 3. High-frequency heating according to claim 1 or 2, characterized in that the impeder core is caused to escape from within the coil by the insertion force of the object to be heated into the heating coil. Device.