JP4237100B2 - Induction heating roller device - Google Patents

Description

  The present invention relates to an induction heating roller device in which induction heating coils having different winding directions are alternately arranged in a hollow interior of a rotating roll.

  In general, an induction heating roller device has a magnetic flux generating mechanism in which an induction heating coil is wound around an iron core in a hollow of a rotating roll, an AC voltage is applied to the induction heating coil, and an alternating magnetic flux generated by this application is used. The roll is heated. FIG. 2 shows an example of such an induction heat roller device. In FIG. 2, 1 is a hollow roll. The hollow roll 1 is rotatably supported by a bearing 3 with respect to a gantry 2 and is driven to rotate by a rotation source (not shown). Reference numeral 4 denotes a sealed chamber formed in the thick portion of the roll 1, and a gas-liquid two-phase heat medium is sealed inside.

  In the hollow of the roll 1, a plurality of (in this example, five) induction heating coils L1 to L5 wound around the iron core 5 along the axial direction are sequentially arranged. Reference numeral 6 denotes a support rod that supports the iron core 5 and the induction heating coils L1 to L5 wound around the iron core 5. The support rod is supported inside the journal 8 connected to the roll 1 via a bearing 7. Reference numeral 9 denotes lead wires of the induction heating coils L1 to L5, which are led out through the support rod 6 and connected to an external AC power source.

  Among the induction heating coils L1 to L5 arranged along the axial direction in the hollow of the roll 1, the induction heating coils L2 and L4 are winding directions of the induction heating coils L1, L3 and L5 (hereinafter referred to as forward windings). Is wound in the opposite direction (hereinafter referred to as reverse winding). That is, the forward winding induction heating coils (L1, L3, L5) and the reverse winding induction heating coils (L2, L4) are alternately arranged. As shown in FIG. 3B, the induction heating coils L1 to L5 are connected in series, and the connection point between the forward winding induction heating coil L1 and the reverse winding induction heating coil L2 and the forward winding induction heating coil L3 and the reverse winding. The connection point of the induction heating coil L4 and the outermost end portion of the forward winding induction heating coil L5 located at one end and one potential terminal V of the AC power source 10 are connected, and the reverse winding induction heating coil L2 and the forward winding induction are connected. The connection point of the heating coil L3, the connection point of the reverse winding induction heating coil L4 and the forward winding induction heating coil L5, the extreme end of the forward winding induction heating coil L5 located at the other end, and the other potential terminal of the AC power supply 10 U is connected through a voltage regulator 11 such as a thyristor.

With this connection, the direction of the current flowing through the adjacent induction heating coils is reversed, but the direction of the magnetic flux generated by each induction heating coil is the same. When an AC voltage is applied to each induction heating coil L1... L5 from an AC power source, each induction heating coil L1... L5 generates an alternating magnetic flux directed in the same direction. An alternating current flows, and the roll 1 generates Joule heat by this current. In this case, since the end portions of the adjacent induction heating coils are at the same potential, there is no need to insert an insulating member therebetween, and the space between the adjacent induction heating coils can be narrowed. The amount of reduction is small, and combined with the latent heat transfer by the gas-liquid two-phase heat medium in the sealed chamber 4, the temperature distribution in the axial direction of the outer surface of the roll 1 is made uniform as shown in FIG. I can plan.
JP-A-2002-164159

  However, in the induction heating roller device configured as described above, the heat at the end of the roll is dissipated through the rotating shaft, and therefore the temperatures at both ends in the longitudinal direction of the roll are as shown in FIG. As shown in FIG. 4, there is a problem that the length at which a uniform temperature is obtained, that is, the effective length is short with respect to the entire length of the induction heating coil, while the temperature at the ends on both sides in the longitudinal direction is reduced. It can be said that the temperature of the end portion is still high, and when it is used as a nip roll, for example, there is a problem that the roll is bent by the high pressure sandwiching the load, the end portions of the roll come into contact with each other, and the roll is damaged. If the operating conditions such as the load width and the load conditions are changed, there is a problem that appropriate conditions for the roll suitable diameter profile cannot be obtained.

  The problem to be solved by the present invention is that forward-winding induction heating coils and reverse-winding induction heating coils are alternately arranged and arranged in the hollow interior of the roll, and the same potential is applied between the adjacent induction heating coils. In the induction heating roller device in which the directions of the magnetic fluxes generated by the induction heating coils arranged in the same manner are the same, the voltage applied to each induction heating coil can be adjusted, and this problem is solved.

The present invention includes a rotating roll, a forward winding induction heating coil wound in the forward direction, a reverse winding induction heating coil wound in the reverse direction, and an alternating current that applies a voltage to each induction heating coil. The forward-winding induction heating coil and the reverse-winding induction heating coil are alternately arranged in a narrow space without inserting an insulating material between the induction coils and disposed inside the hollow of the roll. In the induction heating roller device in which the direction of the magnetic flux generated by each induction heating coil arranged by applying the same potential between adjacent induction heating coils is the same, one forward winding induction heating coil and one reverse winding induction heating coil As a set, a plurality of sets of forward-winding induction heating coils and reverse-winding induction heating coils are alternately arranged in sequence, and the connection points of the arranged forward-winding induction heating coils and the reverse-winding induction heating coils and the reverse-winding induction heating. Coil and forward winding induction heating Either connection point yl connection point connected to one potential of said AC power source, the other connection point is connected to the other of the potential of said AC power source, a predetermined connection point before SL other connection point The main feature is that a voltage regulator is inserted for each.

  According to the invention, since the forward-winding induction heating coil and the reverse-winding induction heating coil are alternately arranged and the end portions of the adjacent induction heating coils are set to the same potential, the space between the adjacent induction heating coils can be reduced. The temperature distribution in the axial direction of the outer surface can be made uniform, and the voltage applied to the induction heating coil can be adjusted for each pair by combining the forward winding induction heating coil and the reverse winding induction heating coil. And an induction heat roller device adapted to operating conditions such as load conditions.

  Also, the outermost end of the forward-winding induction heating coil located at one end of the roll is connected to the outermost end of the reverse-winding induction heating coil located at the other end, and the connection point is set at the middle of the roll. When connected to an AC power supply having a voltage higher than the voltage applied to each induction heating coil located in the section via a voltage regulator, the temperature at the end of the roll can be increased or decreased as necessary. Thereby, when using as a nip roll etc., the expansion | swelling of the diameter direction of the edge part of a roll can be suppressed, the contact of the edge part of a roll can be prevented, and damage to a roll can be prevented.

  For the purpose of enabling adjustment of the voltage applied to each induction heating coil in which the forward-winding induction heating coil and the reverse-winding induction heating coil are alternately arranged, the forward-winding induction heating coil and the reverse-winding induction heating coil are combined into one set. This was realized by adjusting the voltage applied to the induction heating coil for each group.

FIG. 1 is a connection circuit diagram of an induction heating coil of an induction heating roller device according to an embodiment of the present invention. In FIG. 1, L ₁₁ , L ₁₃ , L ₁₅ and L ₁₇ are forward-winding induction heating coils, L ₁₂ , L ₁₄ , L ₁₆ and L ₁₈ are reverse-winding induction heating coils, and each induction heating coil L _{11 to} L _18. As in the induction heating roller device shown in FIG. 2, a forward winding induction heating coil and a reverse winding induction heating coil are alternately wound around an iron core and arranged in the hollow of the roll, and the induction heating coils L _{11 to} L ₁₈ are connected in series. It is connected to the. In the illustrated example, there are eight induction heating coils, the induction heating coil L ₁₁ located at one end of the roll is a forward winding induction heating coil, and the induction heating coil L ₁₈ located at the other end is reverse winding induction. is a heating coil, the endmost portion of the induction heating coil L ₁₁ is connected to the top end of the induction heating coil L _18.

  Reference numerals 12 to 15 are voltage regulators such as thyristors, 16 is a transformer, and the transformer 16 is input between an input terminal V connected to one potential of an AC power source (not shown) and an input terminal U connected to the other potential and the input terminal UV. Output terminals v, u1, u2 that divide and output the generated AC voltage, and the output voltages of the output terminals u1, u2 output higher AC voltages in the order of the output terminals u1, u2 than the output voltage of the output terminal v. To do.

The connection point between the outermost ends of the outermost end and Gyakumaki induction heating coil L ₁₈ of Junmaki induction heating coil L ₁₁ is connected via a voltage regulator 12 to the output terminal u2 of the transformer 16, Junmaki induction heating coil _{L 11} and the connecting point of Gyakumaki induction heating coil _{L 12,} Junmaki induction heating connection point of the coil _{L 13} and Gyakumaki induction heating coil _{L 14,} Junmaki induction heating coil _{L 15} and Gyakumaki induction heating coil _{L 16} Of the forward winding induction heating coil L ₁₇ and the reverse winding induction heating coil L ₁₈ , that is, in the order of arrangement, the connection point of the forward winding induction heating coil and the adjacent reverse winding induction heating coil is the output terminal v of the transformer 16. Connected to.

The connection point of the reverse wound induction heating coil L ₁₂ and Junmaki induction heating coil L ₁₃ is via a voltage regulator 13, a connection point of the reverse wound induction heating coil L ₁₄ and Junmaki induction heating coil L ₁₅ is a voltage regulator 14, the connection point of the reverse winding induction heating coil L ₁₆ and the forward winding induction heating coil L ₁₇ is connected to the output terminal u 1 of the transformer 16 via the voltage regulator 15. That is, in the order of arrangement, the connection point between the reverse-winding induction heating coil and the adjacent forward-winding induction heating coil is connected to the output terminal u1 of the transformer 16 via the voltage regulator.

By this connection, the connection points of the induction heating coils adjacent to each other can be set to the same potential, and the forward winding induction heating coil L ₁₁ and the reverse winding induction heating coil L ₁₈ located at the end of the roll, the reverse winding induction heating. Coil L ₁₂ and forward winding induction heating coil L ₁₃ , reverse winding induction heating coil L ₁₄ and forward winding induction heating coil L ₁₅ , reverse winding induction heating coil L ₁₆ and forward winding induction heating coil L ₁₇ , each as a set, The voltage applied to the induction heating coils of the set can be adjusted by voltage regulators 12 to 15 inserted for each set. In this case, since the connection point between the outermost ends of the outermost end and Gyakumaki induction heating coil L ₁₈ of Junmaki induction heating coil L ₁₁ is connected via a voltage regulator 12 to the high-output terminal u2, voltage Adjustment of the adjuster 12 can suppress a decrease in the temperature at the end of the roll, and can further decrease the temperature at the end. Furthermore, the temperature of the middle part of the roll can be partially adjusted by individual adjustment of the voltage regulators 13, 14, 15.

  In the above embodiment, the number of induction heating coils is 8 for a single phase, but the number of induction heating coils may be an even number of 4 or more, and for multiphase of 3 or more phases. You may comprise. The number of induction heating coils may be increased, and a plurality of reverse winding induction heating coils and forward winding induction heating coils may be combined into one set, and a voltage regulator may be inserted into each set.

It is a connection circuit diagram of the induction heating coil of the induction heating roller device according to the embodiment of the present invention. It is sectional drawing which shows the structure of the roll part of an induction heating roll apparatus. (A) is a characteristic diagram which shows the temperature distribution in the axial direction of the roll of the conventional induction heating roller apparatus, (b) is a circuit block diagram of the conventional induction heating roll apparatus.

Explanation of symbols

1 roll 5 iron core
6 Support rod 9 Lead wire 10 Power supply 12-15 Thyristor (voltage regulator)
16 transformers L ₁₁ , L ₁₃ , L ₁₅ , L ₁₇ forward winding induction heating coils L ₁₂ , L ₁₄ , L ₁₆ , L ₁₈ reverse winding induction heating coils

Claims (2)

A rotating roll, a forward-winding induction heating coil wound in the forward direction, a reverse-winding induction heating coil wound in the reverse direction, and an AC power source for applying a voltage to each induction heating coil are provided. The forward-winding induction heating coil and the reverse-winding induction heating coil are alternately arranged narrowly without inserting an insulating material between the induction coils and arranged in the hollow interior of the roll, and adjacent induction In the induction heating roller device in which the direction of the magnetic flux generated by each induction heating coil arranged by applying the same potential between the heating coils is the same, one forward winding induction heating coil and one reverse winding induction heating coil are combined, The plurality of sets of forward-winding induction heating coils and reverse-winding induction heating coils are alternately arranged in order, and the connection points of the arranged forward-winding induction heating coils and the reverse-winding induction heating coils, the reverse-winding induction heating coils and the forward winding Induction heating coil connection Connect either one of the connection points of the point on one of the potential of said AC power source, the other connection point is connected to the other of the potential of the alternating current power supply, before SL other predetermined voltage to each connection point of the connection point An induction heating roller device comprising an adjuster inserted therein. Connect the outermost end of the forward-winding induction heating coil located at one end of the roll and the outermost end of the reverse-winding induction heating coil located at the other end, and connect the connection point to the middle of the roll 2. The induction heating roller device according to claim 1, wherein the induction heating roller device is connected to a power source having a potential higher than a potential applied to each induction heating coil located through a voltage regulator.

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