JP3900646B2 - High frequency induction heating coil device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-frequency induction heating coil device, and more specifically, a high-frequency induction heating coil device including a cylindrical high-frequency induction heating coil composed of a plurality of coil elements, and high-frequency induction in the axial direction of the high-frequency induction heating coil. The present invention relates to a high frequency induction heating coil device capable of moving an object to be heated in a heating coil.
[0002]
[Prior art]
In a state where conductive heated objects such as metal can lids, metal caps or painted metal plates are stacked, it passes through a cylindrical high frequency induction heating coil for preheating, sterilization, softening of sealing compound, etc. Conventionally, when heating to a temperature range, a spiral high frequency induction heating coil has been used. In this case, there is a time when it is necessary to interrupt the feeding of the heated body due to a failure of the process after heating the heated body and simultaneously turn off the high-frequency induction heating coil. At this time, the object to be heated, which has been heated halfway, is cooled. Therefore, it is necessary to return the object to be heated in the high-frequency induction heating coil to the position before the entrance of the coil before resuming the work. However, this is difficult with a spiral high-frequency induction heating coil.
[0003]
[Problems to be solved by the invention]
In the present invention, the object to be heated in the cylindrical high-frequency induction heating coil device can be moved in the axial direction of the high-frequency induction heating coil by placing it on the conveying tool when heating is stopped, and with relatively high heating efficiency. An object of the present invention is to provide a high-frequency induction heating coil device having the same.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, when the coil element is circular, the center of the circle is the central angle θ, which is the apex angle, and when the coil element is square, the intersection of the diagonal lines of the square Is an apex angle, and when the coil element is elliptical, the center angle θ whose apex angle is the center of the ellipse is a plurality of even-numbered (2 m) coil elements having a missing portion of 10 to 90 degrees. there is disposed in the axial direction, a high-frequency induction heating coil device comprising a slit-shaped cylindrical high-frequency induction heating coil formed an opening extending in the axial direction by the missing portion, the high-frequency induction heating coil The first side edge of the missing portion of the nth coil element from the first end (n is an integer from 1 to m) is the same as the missing portion of the nth coil element from the second end. The first side edge on the side is directly connected and from the first end (n The second side edge of the missing portion of the (+1) th coil element and the second side edge on the same side of the nth missing portion from the second end are directly connected, and the first side The second side edge of the missing part of the first coil element from the end and the second side edge of the missing part of the mth coil element from the second end are connected to the high-frequency power source , The high-frequency induction heating coil is configured to be surrounded by a high magnetic permeability material having a slit at a location corresponding to the opening.
Therefore, the direction of the current flowing through the plural (m) coil elements in one half of the coil and the plural (m) coil elements in the other half is opposite.
[0005]
If the coil element is circular with respect to the central angle, the center of the circle is the apex angle.If the coil element is square, the intersection of the diagonals of the quadrangle is the apex angle. It becomes a corner.
The high-frequency induction heating coil is formed of a plurality of even-numbered (2 m) coil elements having a missing portion arranged in the axial direction, extending in the axial direction by the missing portion, and having a central angle θ of 10 Since the opening portion is formed at a degree or more, the object to be heated can be moved in the axial direction of the high-frequency induction heating coil by providing the support arm of the transfer tool in the opening portion.
As described above, since the direction of the current flowing through the plurality (m) of coil elements in one half of the coil and the plurality of (m) coil elements in the other half is opposite, one half and the other Except that the heating efficiency slightly decreases in the portion between the halves, it is possible to obtain a heating efficiency substantially equal to that when the current flow direction is the same over the entire length (see curves 1, 2, and 4 in FIG. 5).
Further, since the magnetic flux is canceled near the center of the coil, the coil length can be increased (for example, about 30 cm or more). However, in the case of the conventional spiral coil, if it becomes long (for example, about 30 cm or more), the magnetic flux is saturated, the matching with the high frequency oscillator is lost, the oscillation stops, and heating cannot be performed.
It is not preferable that the central angle θ exceeds 90 degrees because the density of the induced current circulating in the circumferential direction of the heated object is reduced at the missing portion, and the heating efficiency is likely to be lowered.
[0006]
The invention according to claim 2 is the high-frequency induction heating coil device according to claim 1, wherein a support arm of the carrier that is movable along the opening is provided.
Since the support arm of the transporting tool that can move along the opening is provided, a high-frequency induction heating coil device is provided by placing an object to be heated on the transporting tool and moving the support arm along the opening. It is possible to move the inner body to be heated in the axial direction of the high frequency induction heating coil.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2, reference numeral 1 denotes a high-frequency induction heating coil device, which is a cylindrical high-frequency induction heating coil as a whole except for a slit-shaped opening 2a extending in the axial direction in a part of the circumferential direction. 2 is provided. The high-frequency induction heating coil 2 includes a plurality of even-numbered coil elements 3 (eight in FIG. 2). That is, the coil elements 3 are provided in the order of the coil elements 3a, 3b, 3c, 3d, 3e, 3f, 3g and 3f from above.
The coil elements 3a, 3b, 3c, 3d, 3e, 3f, 3g and 3h are equal in diameter, concentric and perpendicular to the axial direction, and are equidistant from each other, that is, the distance h between the coil elements is equal, and In the same position in the circumferential direction, each of the missing circular portions 3a1, 3b1, 3c1, 3d1, 3e1, 3f1, 3g1 and the central angle θ of 10 to 90 degrees, more preferably 20 to 70 degrees, forming the opening 2a and 3h1. The intervals between the coil elements are not necessarily equal.
[0008]
The right side edge 3a2 of the cutout 3a1 of the uppermost coil element 3a is connected to a high frequency oscillator 37 (see FIG. 4). The left side edge 3a3 is connected to the left side edge 3h3 of the lowermost coil element 3h through the falling conduit 4, and the right side edge 3h2 is connected to the top 2 through the rising conduit 5 from above. The second coil element 3b is connected to the right end 3b2 of the missing circle 3b1. The left side edge 3b3 of the missing circle part 3b1 is connected to the left side edge 3g3 of the missing circle part 3g1 of the second coil element 3g from the bottom through the falling conduit 6, and the right side edge thereof. 3g2 is connected to the right side edge 3c2 of the missing circle 3c1 of the third coil element 3c from the top through the rising conduit 7. The left side edge 3c3 of the missing circle part 3c1 is connected to the left side edge 3f3 of the missing circle part 3f1 of the third coil element 3f from the bottom via the falling conduit 8, and the right side of the missing circle part 3f1 The side edge 3f2 is connected to the right side edge 3d2 of the cutout 3d1 of the fourth coil element 3d from the top through the rising conduit 9. The left side edge 3d3 of the missing circle part 3d1 is connected to the left side edge 3e3 of the missing circle part 3e1 of the fourth coil element 3e from the bottom via the falling conduit 10, and the right side of the missing circle part 3e1. The side edge 3e3 is connected to the high frequency oscillator 37 via the rising conduit 11.
Therefore, the high-frequency current flows in the same direction in the upper half coil elements 3a, 3b, 3c, and 3d, and the current in the same direction flows in the lower half coil elements 3e, 3f, 3g, and 3h. It flows in the direction opposite to the current flow of 3b, 3c, 3d.
[0009]
The high frequency induction heating coil device 1 includes a cylindrical high magnetic permeability material, for example, a ferrite 14 that surrounds the high frequency induction heating coil 2 and has a slit 14a corresponding to the opening 2a. It is preferable for reducing or increasing the heating efficiency.
Reference numeral 15 denotes a support arm of the transport tool 12 for moving the object to be heated through the opening 2a in the axial direction. As shown in FIGS. 1 and 3, a hole 15 a is provided at the rear end of the support arm 15, and the pin 17 of the joint 16 is inserted into the hole 15 a, and the support arm 15 is arranged around the pin 17. Can be rotated. Normally, the support arm 15 is rotated to the position indicated by the alternate long and short dash line, and the carrier 12 is not in the high frequency induction heating coil 2.
A spring 18 is provided to push the support arm 15 toward the lower portion of the joint 16 and increase the frictional force so that the transport tool 12 is difficult to rotate during movement.
[0010]
The joint 16 is fixed to a moving piece 20 that can move up and down in a guide cylinder 19 having a slit 19a extending in the height direction via a connecting arm 21 that passes through the slit 19a. An upper wire 22 and a lower wire 23 are attached to the moving piece 20. The upper wire 22 is wound around the upper end of a drum (not shown) provided on the output shaft of a reversible motor (not shown) with a speed reducer. A weight (not shown) is suspended from the lower end of the lower wire 23. Therefore, since tension acts on the upper wire 22, the moving piece 20 can be moved up and down stably.
[0011]
Next, the case where the high frequency induction heating coil device 1 is applied to heat sterilize the can lid for aseptic filling and sealing can production (for example, beer can) will be described.
In FIG. 4, the high frequency induction heating coil 2 surrounds a fixed vertical guide cylinder 36 made of a heat-resistant insulator such as a thermosetting resin, for example, bakelite, and includes an upper flange portion 36a and a lower flange portion 36b of the guide cylinder 36. Located between. The inner diameter of the guide tube 36 is slightly larger than the diameter of the can lid 40 that passes through the guide tube 36 (for example, about 2 to 3 mm larger). The high frequency induction heating coil 2 is connected to a high frequency oscillator 37 by a feeder 38.
[0012]
Four guide rods 41 made of round bars are arranged at equal intervals in the circumferential direction, curved obliquely downward, and the can lids 40 descending in a state of being piled on each other by their own weight are placed on the high frequency induction heating coil. It leads to the device 1.
An air cooling device 43 in which aseptic air 42 flows in a substantially horizontal direction from the left side to the right side of the drawing is disposed near the high frequency induction heating coil device 1 and below, and a filling and sealing device is provided below the air cooling device 43. (Not shown) is provided. 44a and 44b are vertical guides. A radiation thermometer 45 is provided at a height position between the high frequency induction heating coil device 1 and the guide 44 a on the air cooling device 43, and an output signal of the radiation thermometer 45 is input to the high frequency oscillator 37. Thus, the output of the high frequency oscillator 37 is controlled. The guide cylinder 19 and the moving piece 20 are disposed behind the high-frequency induction heating coil 2 and are not shown in FIG.
[0013]
During normal filling and sealing, the can lids 40 stacked and lowered are heated by the high frequency induction heating coil device 1 (for example, about 130 ° C. × 5 to 10 seconds), and then filled through the air cooling chamber 43. It is cooled to about 50 ° C. before entering the sealing device.
When the filling and sealing device stops due to a failure or the like, the high frequency oscillator 37 is immediately turned off. At the same time, a stopper (not shown) is operated to stop the lowering of the can lid 40. Immediately turning the support arm 15, the transport tool 12 is inserted between the can lid 40 through the gap between the guide 44 a near the lower end of the heating coil 2 and the guide tube 36, and a motor (not shown) rotates. Then, the support arm 15 is raised, and the can lid 40 on the carrier 12 is pushed up above the high frequency induction heating coil device 1.
The can lid 40 remaining between the conveying tool 12 and the inlet of the filling and sealing device is sent to the filling and sealing device as it is.
[0014]
【Example】
A test example in which a can lid 40 made of an aluminum alloy is heated using the high frequency induction heating coil device 1 of the type shown in FIGS. 1 and 2 will be described below.
As the high-frequency induction heating coil device 1, the number of coil elements of the high-frequency induction heating coil 2 is 8, and the inner diameters of the coil elements 3a, 3b, 3c, 3d, 3e, 3f, 3g, and 3h are 65 mm. The outer diameter of the conduit (copper tube) to be formed was 5 mm, the interval h in the height direction of each coil element 3a and the like was 25 mm, and the total height of the high frequency induction heating coil 2 was 30 cm. The center angle θ of each missing circle portion was 25 degrees, and the width (d) of the opening 2a was 18 mm. The high frequency induction heating coil 2 was surrounded by a cylindrical ferrite 14 having a thickness of 8 mm.
The diameter of the can lid was 60 mm, and 100 sheets were stacked on a bakelite rod (not shown) at room temperature (25 ° C.), and inserted into the high-frequency induction heating coil device 1 with a total height of 30 cm. . A blackening paint was applied in advance to the side surface of the stacked can lids 40.
In this state, the output of the high-frequency oscillator 37 (frequency 23.5 kHz) is set to 145 V, 20 A, heated for 1 minute, and immediately after the entire can lid 40 is lowered directly below the high-frequency induction heating coil device 1 and stopped, The temperature of the portion facing the opening 2a of the can lid 40 and the portion on the opposite side in the circumferential direction was measured every 5 cm in the height direction.
The results are shown in FIG. Curve 1 shows the temperature 180 degrees opposite to the opening 2a, and curve 2 shows the temperature on the opening 2a side. It can be seen that there is almost no difference in heating temperature between the portion facing the opening 2a and the 180 ° opposite side. The reason why the temperature is slightly lower at approximately the center in the height direction seems to be that the direction of the current is reversed here, so that the high-frequency induction action is canceled out.
[0015]
Comparative Example 1:
The can lid 40 was heated in the same manner using a high-frequency induction heating coil device (not shown) similar to the high-frequency induction heating coil device 1 except that the central angle θ was 110 degrees. The result of measuring the temperature on the opening side is shown by curve 3 in FIG.
Comparative Example 2:
Except for the fact that the high-frequency induction heating coil has a spiral shape, the results of a similar test using a high-frequency induction heating coil device (not shown) similar to the high-frequency induction heating coil device 1 are shown in the curve of FIG. 4 shows. It can be seen that there is almost no difference from the curves 1 and 2 except for the vicinity of the center in the height direction.
[0016]
【The invention's effect】
The cylindrical high-frequency induction heating coil device of the present invention includes a support arm for a transporting tool, so that the internal heated body can be moved in the axial direction using the transporting tool and is relatively high. There is an effect of having heating efficiency.
[Brief description of the drawings]
FIG. 1 is a plan view of a high-frequency induction heating coil device according to an embodiment of the present invention.
2 is a front view of a main part of the high-frequency induction heating coil device of FIG. 1 as seen from the II-II line side of FIG. 1;
FIG. 3 is a partially cutaway side view of FIG. 1 excluding the high-frequency induction heating coil device, showing a moving mechanism of the transport tool and the support arm.
FIG. 4 is a partially cut front view of an example of an apparatus for heating a can lid using the high frequency induction heating coil apparatus of FIG. 1;
FIG. 5 is a graph showing the relationship between the height direction position and the heating temperature when the stacked can lids are heated using the high frequency induction heating coil device of FIG. 1 and the high frequency induction heating coil device of the comparative example. It is a diagram which shows an example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 High frequency induction heating coil apparatus 2 High frequency induction heating coil 2a Opening part 3 Coil element 3a The 1st coil element 3b from the 1st end part The 2nd coil element 3c from the 1st end part 3rd from the 1st end part Coil element 3d 4th coil element 3e from the 1st end 4th coil element 3f from the 2nd end 3rd coil element 3g from the 2nd end 2nd coil from the 2nd end Element 3h The first coil element 3a1 from the second end part.
3b1 Missing circle (missing part)
3c1 Missing circle (missing part)
3d1 missing circle (missing part)
3e1 Missing circle (missing part)
3f1 missing circle part (missing part)
3g1 missing circle part (missing part)
3h1 Missing circle (missing part)
3a2 2nd side edge 3b2 2nd side edge 3c2 2nd side edge 3d2 2nd side edge 3e2 2nd side edge 3f2 2nd side edge 3g2 2nd side edge 3h2 Second side edge 3a3 First side edge 3b3 First side edge 3c3 First side edge 3d3 First side edge 3e3 First side edge 3f3 First side edge 3g3 1 side edge portion 3h3 first side edge portion 12 carrier 15 support arm 37 high frequency oscillator (high frequency power source)

Claims (2)

When the coil element is circular, the center angle θ is the apex angle of the center of the circle. When the coil element is quadrangular, the intersection of the diagonals of the square is the center angle θ that is the apex angle, and the coil element is elliptical. In this case, a plurality of even-numbered (2 m) coil elements having a missing portion whose center angle θ is an apex angle of the center of the ellipse is 10 to 90 degrees are arranged in the axial direction. A high-frequency induction heating coil device including a cylindrical high-frequency induction heating coil formed with a slit-like opening extending to
The high-frequency induction heating coil includes a first side edge portion of a missing portion of an n-th coil element (n is an integer from 1 to m) from a first end portion and an n-th coil from a second end portion. The first side edge on the same side of the missing part of the element is directly connected, and the second side edge of the missing part of the (n + 1) th coil element from the first end, and the second side edge The second side edge on the same side of the nth missing part from the end is directly connected, and the second side edge of the missing part of the first coil element from the first end, The second side edge of the missing part of the m-th coil element from the end of 2 is connected to a high-frequency power source ;
The high frequency induction heating coil is surrounded by a high permeability material having a slit at a location corresponding to the opening,
A high-frequency induction heating coil device characterized by that. Along said opening movable in the axial direction, high-frequency induction heating coil device of claim 1, wherein the support arm of the transfer device is provided.

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