EP-4742833-A1 - INDUCTION HEATED ROLL APPARATUS

Abstract

A signal transmission device for transmitting a detection signal of a temperature sensor provided to a roll, includes: a light transmission unit provided on a rotating side of an apparatus which outputs light in accordance with the detection signal; a light reception unit provided on a stationary side of the apparatus which receives light from the light transmission unit; a rotary transformer, in which a stationary-side coil and a rotating-side coil are electromagnetically coupled, that supplies power to the light transmission unit in a contactless manner; and an adjustment unit that adjusts an alternating-current voltage supplied to the stationary-side coil. The stationary-side coil and the rotating-side coil delineate an annular shape wound around a rotation axis of the roll, and are provided facing each other with a gap therebetween along the rotation axis direction. The adjustment unit supplies reference voltage for the light transmission unit to the rotating-side coil.

Inventors

• KIMURA, MASAYOSHI

Assignees

• Tokuden Co., Ltd.

Dates

Publication Date

20260513

Application Date

20251001

Claims (5)

1. An induction heated roll apparatus, comprising: a roll that is hollow and is rotatably provided about a rotation axis; an induction heating mechanism disposed in a hollow space of the roll; a temperature sensor provided in the roll and configured to detect a temperature of the roll; and a signal transmission device configured to transmit a detection signal of the temperature sensor to a temperature control device on a stationary side of the apparatus, in a contactless manner, the signal transmission device including: a light transmission unit provided on a rotating side of the apparatus and configured to output light in accordance with the detection signal; a light reception unit provided on the stationary side and configured to receive the light from the light transmission unit; a rotary transformer including a stationary-side coil and a rotating-side coil that are electromagnetically coupled to each other, and configured to supply power to the light transmission unit in a contactless manner; and an alternating-current voltage adjustment unit configured to adjust alternating-current voltage to be supplied to the stationary-side coil, wherein the stationary-side coil and the rotating-side coil delineate an annular shape that is wound around the rotation axis of the roll, and are provided in a manner facing each other with a gap between the stationary-side coil and the rotating-side coil along a rotation axis direction of the roll, and wherein the alternating-current voltage adjustment unit supplies a reference voltage necessary for the light transmission unit to operate, to the rotating-side coil, by adjusting a frequency or an amplitude of the alternating-current voltage.
2. The induction heated roll apparatus according to claim 1, wherein the light transmission unit and the light reception unit are disposed along the rotation axis of the roll, with the rotary transformer interposed between the light transmission unit and the light reception unit, and transmit and receive light through center openings of the stationary-side coil and the rotating-side coil.
3. The induction heated roll apparatus according to claim 2, wherein the light transmission unit includes a light-emitting element disposed on the rotation axis of the roll, and wherein the light reception unit includes a light-receiving element disposed on the rotation axis of the roll.
4. The induction heated roll apparatus according to claim 2, wherein the rotary transformer further includes: a stationary-side resin seal in which the stationary-side coil is sealed with an insulating resin; and a rotating-side resin seal in which the rotating-side coil is sealed with the insulating resin, wherein the stationary-side resin seal has a pass-through part corresponding to the center opening of the stationary-side coil, wherein the rotating-side resin seal has a pass-through part corresponding to the center opening of the rotating-side coil, and wherein the light transmission unit transmits light and the light reception unit receives light through the pass-through parts of the stationary-side resin seal and the rotating-side resin seal.
5. The induction heated roll apparatus according to claim 4, wherein the stationary-side resin seal seals the stationary-side coil, together with a plurality of ferrite cores that are disposed radially with respect to a winding center of the stationary-side coil, and wherein the rotating-side resin seal seals the rotating-side coil, together with a plurality of ferrite cores that are disposed radially with respect to a winding center of the rotating-side coil.

Description

BACKGROUND TECHNICAL FIELD The present disclosure relates to an induction heated roll apparatus. BACKGROUND ART Having been conventionally developed, in order to control the heating temperature of a roll included in an induction heated roll apparatus, is an induction heated roll apparatus including a roll provided with an internal temperature sensor, and a signal transmission device configured to transmit a detection signal of the temperature sensor to a temperature control device provided on a stationary side of the apparatus, in a contactless manner, as disclosed in JP 2022-55545 A. This signal transmission device includes: a light transmission unit that is provided on a rotating side of the apparatus and that outputs light in accordance with a detection signal; a light reception unit that is provided on the stationary side and that receives the light from the light transmission unit; and a rotary transformer that includes a stationary-side coil and a rotating-side coil electromagnetically coupled to each other, and that supplies power to the light transmission unit, in a contactless manner. Each of the stationary-side coil and the rotating-side coil of the rotary transformer has a cylindrical shape wound about a rotation axis of the roll, and is provided in a manner facing the other in a radial direction. REFERENCE DOCUMENT Patent Document 1: JP 2022-55545 A SUMMARY In a conventional configuration in which a stationary-side coil and a rotating-side coil are provided facing each other in a radial direction (in other words, the coils are concentric), a distance of a gap between the stationary-side coil and the rotating-side coil is less likely to change, so that power can be supplied stably to a light transmission unit. By contrast, in a configuration in which the stationary-side coil and the rotating-side coil are provided facing each other in a direction of a rotation axis (axial direction) of a roll, the distance of the gap between the stationary-side coil and the rotating-side coil may change due to an assembly error in a signal transmission device. The distance of the gap between the stationary-side coil and the rotating-side coil may also change during an operation of an induction heated roll apparatus due to a difference in thermal expansions of members such as the roll. If the distance of the gap between the stationary-side coil and the rotating-side coil changes, as described above, a voltage necessary for the light transmission unit to operate may fail to be supplied to the rotating-side coil. Although it is conceivable to supply alternating-current voltage high enough for the stationary-side coil to supply the voltage necessary for the light transmission unit to operate, to the stationary-side coil, regardless of the distance of the gap between the rotating-side coil and the stationary-side coil, power is consumed wastefully. With the foregoing in view, the present disclosure has been made to solve the problems described above, and a main object of the present disclosure is to improve the stability of light transmission, while suppressing power consumption, of the signal transmission device for transmitting a detection signal of a temperature sensor provided to a roll to a stationary side. That is, the induction heated roll apparatus according to the present disclosure includes: the roll that is hollow and is rotatably provided about the rotation axis; an induction heating mechanism disposed in a hollow space of the roll; the temperature sensor provided in the roll and configured to detect a temperature of the roll; and the signal transmission device configured to transmit the detection signal of the temperature sensor to a temperature control device on the stationary side of the apparatus, in a contactless manner, in which the signal transmission device includes: a light transmission unit provided on a rotating side of the apparatus and configured to output light in accordance with the detection signal; a light reception unit provided on the stationary side and configured to receive the light from the light transmission unit; a rotary transformer including the stationary-side coil and the rotating-side coil that are electromagnetically coupled to each other, and configured to supply the power to the light transmission unit in a contactless manner; and an alternating-current voltage adjustment unit configured to adjust the alternating-current voltage to be supplied to the stationary-side coil, in which the stationary-side coil and the rotating-side coil delineate an annular shape that is wound around the rotation axis of the roll, and are provided in a manner facing each other with a gap between the stationary-side coil and the rotating-side coil along a rotation axis direction of the roll, and in which the alternating-current voltage adjustment unit supplies a reference voltage necessary for the light transmission unit to operate, to the rotating-side coil, by adjusting a frequency or an amplit