Induction heated roll apparatus

Abstract

This invention provides an induction heating roller device that can adjust the thermal expansion of the roller body at a desired position along its axial direction, regardless of the amount of heat absorbed by the heated object from the roller body. The induction heating roller device includes: a hollow cylindrical roller body; multiple induction coils arranged axially inside the roller body; a power supply circuit that individually controls the power supplied to the multiple induction coils; and a cooling mechanism that supplies refrigerant to the roller body to cool it.

Description

Technical Field

[0001] This invention relates to an induction heating roller device. Prior Technology

[0002] For example, in the calendering process of sheet-shaped heated materials, a pair of induction heating roller devices are used, and the roller bodies of each induction heating roller device bend due to the load. Due to the bending of the roller bodies, it is difficult to perform uniform calendering of sheet-shaped heated materials.

[0003] As a countermeasure, as shown in Patent Document 1, it is possible to arrange multiple induction coils axially within the hollow interior of the roller body and individually control the voltage of each coil. This induction heating roller device, by individually controlling the voltage of each coil, creates a thermal difference between the portions of the roller body opposite to each coil, causing localized thermal expansion only in designated areas, thereby adjusting the diameter profile of the roller body. This allows for a uniform thickness distribution of the sheet-like heated material.

[0004] However, in this induction heating roller device, the output of multiple induction coils as a whole only corresponds to the load heat that the sheet-like heated material takes away from the roller body. Therefore, it is sometimes impossible to provide the output used to make the thickness distribution of the sheet-like heated material uniform. For example, in sheet processing with low load heat, the output of the multiple induction coils as a whole becomes small, and the output difference between the induction coils used to make the thickness distribution uniform cannot be obtained, thus making it impossible to eliminate uneven thickness distribution. [Existing technical documents] [Patent Literature]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 62-178494 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] Therefore, in order to solve the above problems, the main objective of the present invention is to be able to adjust the amount of thermal expansion at the desired position in the axial direction of the roller body, regardless of how much load heat the heated object takes away from the roller body. [Methods for solving problems]

[0008] That is, the induction heating roller device of the present invention includes: a hollow cylindrical roller body; a plurality of induction coils arranged axially within the hollow of the roller body; a power supply circuit that individually controls the power supplied to the plurality of induction coils; and a cooling mechanism that supplies refrigerant to the roller body to cool the roller body.

[0009] In the case of such an induction heating roller device, the power supplied to multiple induction coils can be individually controlled by the power circuit, thereby adjusting the amount of thermal expansion at the desired position in the axial direction of the roller body. Furthermore, in this invention, since the roller body is cooled by a cooling mechanism, the required load heat can be replenished by the cooling mechanism when the load heat absorbed by the heated object from the roller body is small. Regardless of the amount of load heat absorbed by the heated object from the roller body, the amount of thermal expansion at the desired position in the axial direction of the roller body can be adjusted.

[0010] In a preferred embodiment of the induction heating roller device, the induction heating roller device heats the sheet-like object to be heated, and the power supply circuit individually controls the power supplied to the plurality of induction coils in a manner that makes the temperature of the roller body reach a predetermined temperature and makes the object to be heated have a predetermined thickness distribution.

[0011] In order to efficiently adjust the thermal expansion of the roller body at the desired position in the axial direction according to the load heat, the induction heating roller device preferably also includes a cooling mechanism control unit, which controls the supply of refrigerant to the cooling mechanism according to the load heat.

[0012] In this invention, by individually controlling the power of multiple induction coils, a temperature difference based on the difference in heat generation is generated on the inner surface of the roller body. Additionally, a temperature difference based on the difference in heat absorbed by the heated object is generated on the outer surface of the roller body. To eliminate these temperature differences and make the temperature of the outer surface of the roller body uniform, preferably, a jacketed chamber containing a gas-liquid two-phase heat medium is formed on the side wall of the roller body.

[0013] As a specific implementation of the cooling mechanism, preferably, the cooling mechanism supplies refrigerant into the hollow space of the roller body. With this configuration, it is only necessary to allow the coolant to flow through the gap between the inner surface of the roller body and the induction coil, thereby simplifying the configuration of the cooling mechanism.

[0014] Preferably, the cooling mechanism supplies refrigerant to a refrigerant flow channel formed on the side peripheral wall of the roller body, which is radially inner than the jacket chamber. With this configuration, the sidewalls of the roller body can be cooled efficiently.

[0015] Preferably, the cooling mechanism supplies refrigerant individually to the portions of the inner surface of the roller body that are opposite to the plurality of induction coils. With this configuration, localized low-temperature treatment can be achieved at a specified location on the inner surface of the roller body, thereby maximizing the axial relative difference (thermal expansion difference) of the deformation caused by thermal expansion. [The effects of the invention]

[0016] According to the present invention configured in this way, regardless of the amount of load heat taken away by the heated object from the roller body, the amount of thermal expansion at the desired position in the axial direction of the roller body can be adjusted. Simple Explanation of the Diagram

[0017] Figure 1 is a cross-sectional view schematically showing the configuration of an induction heating roller device according to one embodiment of the present invention. Figure 2 is a partially enlarged cross-sectional view showing the flow of refrigerant in this embodiment. Figure 3 is a schematic diagram illustrating the function of the cooling mechanism in this embodiment. Figure 4 is a partially enlarged cross-sectional view showing the flow of refrigerant in a modified embodiment. Figure 5 is a partially enlarged cross-sectional view showing the flow of refrigerant in a modified embodiment. Implementation

[0018] <One embodiment of the present invention> An embodiment of the induction heating roller device 100 of the present invention will be described below with reference to the accompanying drawings.

[0019] The induction heating roller device 100 is used, for example, in heat treatment processes of sheet-shaped materials such as plastic film, paper, cloth, non-woven fabric, synthetic fiber, and metal foil. For example, two induction heating roller devices 100 can be used for calendering of sheet-shaped materials W.

[0020] As shown in Figure 1, the induction heating roller device 100 of this embodiment includes: a hollow cylindrical roller body 2, which is rotatably supported; and an induction heating mechanism 3, which is disposed inside the roller body 2.

[0021] At both ends of the roller body 2, there are journals 4 with hollow drive shafts 41, which are rotatably supported on the base 9 by bearings 8 such as ball bearings. The journals 4 also have the drive shaft 41 and flanges 42 fixed to the axial ends of the roller body 2. The roller body 2 rotates using an externally applied driving force from a rotary drive mechanism (not shown), such as a motor. Furthermore, in this embodiment, a jacketed chamber 2A is formed along the long side direction (rotation axis direction) of the side peripheral wall of the roller body 2, and a gas-liquid two-phase heat medium is sealed in the jacketed chamber 2A under reduced pressure. Multiple jacketed chambers 2A are formed at equal intervals along the circumference.

[0022] The induction heating mechanism 3 has a cylindrical iron core 31 in the shape of a cylinder and a plurality of induction coils 32 wound around the outer circumference of the cylindrical iron core 31.

[0023] The two ends of the cylindrical iron core 31 are supported by support shafts 33, which pass through the interior of the drive shaft 41 and are supported by bearings 10 such as ball bearings, allowing the drive shaft 41 to rotate freely. As a result, the induction heating mechanism 3 remains stationary relative to the base 9 (fixed side) inside the rotating roller body 2.

[0024] Furthermore, multiple induction coils 32 are arranged along the axial direction of the roller body 2, and external leads L1 are connected to the multiple induction coils 32 respectively. A power supply circuit 5 for applying an AC voltage or the like at an operating frequency (50Hz or 60Hz) is connected to these external leads L1. The power supply circuit 5 individually controls the power supplied to the multiple induction coils 32 respectively.

[0025] Through this induction heating mechanism 3, if an alternating voltage is applied to the induction coil 32, an alternating magnetic flux is generated, which passes through the side peripheral wall of the roller body 2. Due to this passage, an induced current is generated in the roller body 2, and through this induced current, the roller body 2 generates Joule heat. In addition, through the jacket chamber 2A, the temperature distribution in the rotational axis direction of the side peripheral wall of the roller body 2 becomes uniform.

[0026] Furthermore, the power supply circuit 5 individually controls the power supplied to the multiple induction coils 32 to maintain the temperature of the roller body 2 at a predetermined temperature and the heated object W at a predetermined thickness distribution. Here, the temperature of the roller body 2 is detected by a temperature sensor (not shown) located radially outward from the jacket chamber 2A on the side wall of the roller body 2. Additionally, the thickness distribution of the heated object W is detected, for example, by multiple thickness sensors (not shown) using a laser displacement gauge or similar device.

[0027] Furthermore, the induction heating roller device 100 of this embodiment also includes a cooling mechanism 6, which supplies refrigerant to the roller body 2 to cool the roller body 2.

[0028] The cooling mechanism 6 uses a coolant to remove additional load heat from the roller body 2, based on the load heat removed by the heated object W from the roller body 2. In this embodiment, the cooling mechanism 6 removes insufficient load heat in order to achieve the desired amount of deformation (difference in thermal expansion) in the axial direction of the roller body 2. Here, "insufficient load heat" = "load heat used to achieve the desired amount of deformation (difference in thermal expansion)" - "load heat removed by the heated object from the roller body".

[0029] Specifically, the cooling mechanism 6 supplies refrigerant into the hollow interior of the roller body 2, cooling the inner surface of the roller body 2. This cooling mechanism 6 supplies refrigerant into the hollow interior of the roller body 2, for example, through a refrigerant inlet (not shown) formed on one side of the journal 4 of the roller body 2, and discharges refrigerant through a refrigerant outlet (not shown) formed on the other side of the journal 4. The refrigerant can be a cooling gas cooled to a specified temperature, or a liquid or mist-like coolant.

[0030] The amount of refrigerant supplied by the cooling mechanism 6 is controlled by the cooling mechanism control unit 7 based on the load heat absorbed by the heated object W from the roller body 2. Specifically, when the load heat absorbed by the heated object from the roller body is greater than or equal to the load heat required to achieve the desired deformation, the cooling mechanism control unit 7 sets the amount of refrigerant to zero and does not supply refrigerant to the roller body 2. Conversely, when the load heat required to achieve the desired deformation is greater than the load heat absorbed by the heated object from the roller body, the cooling mechanism control unit 7 supplies the roller body 2 with a predetermined amount of refrigerant based on the insufficient load heat. Furthermore, the cooling mechanism control unit 7 controls the amount of refrigerant by controlling the flow control device 62 installed on the refrigerant supply channel 61 of the cooling mechanism 6. Here, the load heat absorbed by the heated object W from the roller body 2 is calculated based on the power (kW) required for controlling the roller body 2 to a predetermined temperature by the multiple induction coils 32.

[0031] Next, the function of the cooling mechanism 6 will be explained with reference to FIG3. For ease of explanation, FIG3 shows an example using the first to fifth induction coils 32.

[0032] (1) The case where "the load heat taken away by the heated object from the roller body" is ≥ "the load heat used to obtain the desired amount of deformation". The power supply circuit 5 controls the power supplied to the multiple induction coils 32 so that the temperature of the roller body 2 is 200°C, and the load heat taken by the heated object W from the roller body 2 at this time is set to 30kW.

[0033] Here, the power supply circuit 5 individually controls the power supplied to the multiple induction coils 32 to make the thickness distribution of the heated object W after heat treatment uniform. To achieve uniform thickness distribution of the heated object W after heat treatment, the power of the first, second, fourth, and fifth induction coils 32 is set to 5 kW, and the power of the third induction coil 32 is set to 10 kW. To achieve uniform thickness, for example, the difference between the power of the third induction coil and the power of the second induction coil needs to be 5 kW, and the load heat used to obtain the desired deformation amount is 30 kW.

[0034] (2) Case where "the load heat used to obtain the desired amount of deformation" > "the load heat taken away by the heated object from the roller body" Even when the load heat taken away by the heated object from the roller body 2 is 10kW, the power supply circuit 5 controls the power supplied to the multiple induction coils 32 so that the temperature of the roller body 2 is 200°C.

[0035] Although the power supply circuit 5 individually controls the power supplied to the multiple induction coils 32 to make the thickness distribution of the heated object W after heat treatment more uniform, the total power supplied to the multiple induction coils 32 is 10kW. The power of the first, second, fourth, and fifth induction coils 32 is about 1.6kW, and the power of the third induction coil 32 becomes about 3.2kW. Thus, for example, the difference between the power of the third induction coil 32 and the power of the second induction coil 32 becomes about 1.6kW, which does not meet the 5kW required to make the thickness uniform.

[0036] In this case, the insufficient load heat of 20kW is compensated by cooling the roller body 2 through the cooling mechanism 6, thereby supplying 30kW of power to the multiple induction coils 32 by the power supply circuit 5. Thus, the power of the first, second, fourth, and fifth induction coils 32 becomes 5kW, and the power of the third induction coil 32 becomes 10kW, thereby achieving the load heat required to obtain the desired amount of deformation. As a result, the thickness distribution of the heated object W after heat treatment becomes uniform.

[0037] <Effects of this implementation method> The induction heating roller device 100 configured in this way allows for individual control of the power supplied to multiple induction coils 32 via the power supply circuit 5, thereby enabling adjustment of the thermal expansion at a desired position in the axial direction of the roller body 2. Furthermore, in this embodiment, the roller body 2 is cooled by the cooling mechanism 6. Therefore, even when the load heat absorbed by the heated object W from the roller body 2 is small, the cooling mechanism 6 can replenish the load heat required to achieve uniform thickness distribution of the heated object W. Thus, regardless of the load heat absorbed by the heated object W from the roller body 2, the thermal expansion at a desired position in the axial direction of the roller body 2 can be adjusted. Moreover, when using the induction heating roller device 100 of this embodiment for calendering sheet-shaped heated objects W, uniform clamping pressure can be achieved, thereby enabling the manufacture of high-quality sheet products.

[0038] <Other variations and implementations> For example, as shown in Figure 4, the cooling mechanism 6 can also supply refrigerant to a refrigerant flow channel 21 formed on the side peripheral wall of the roller body 2, which is radially inward than the jacket chamber 2A. Multiple refrigerant flow channels 21 are formed at equal intervals along the circumference. The cooling mechanism 6 supplies refrigerant to the refrigerant flow channel 21 from a refrigerant inlet formed on, for example, one side of the journal 4 of the roller body, and discharges refrigerant from a refrigerant outlet formed on the other side of the journal 4.

[0039] Furthermore, as shown in Figure 5, preferably, the cooling mechanism 6 supplies refrigerant individually to portions of the inner surface of the roller body 2 opposite to the plurality of induction coils 32. Specifically, the cooling mechanism 6 has a plurality of refrigerant supply ports 63, which can switch between supplying and not supplying refrigerant from the plurality of refrigerant supply ports 63. For example, it is conceivable that the cooling mechanism 6 has a plurality of supply pipes 64 each having a plurality of refrigerant supply ports 63, and that each of the plurality of supply pipes 64 is provided with a switching valve (not shown). In addition, the number of refrigerant supply ports 63 may be the same as or different from the number of induction coils 32. With this configuration, a specific portion of the inner surface of the roller body 2 can be locally cooled, thereby maximizing the axial relative difference (thermal expansion difference) of the deformation caused by thermal expansion.

[0040] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0041] 2: Roller body 2A: Jacketed Chamber 3: Induction heating mechanism 4: Journal 5: Power supply circuit 6: Cooling mechanism 7: Cooling Mechanism Control Unit 8, 10: Bearings 9: Base 21: Refrigerant Circulation Channel 31: Cylindrical iron core 32: Induction coil 33: Support shaft 41: Drive shaft 42: Flange 61: Refrigerant Supply Channel 62: Flow control equipment 63: Refrigerant supply port 64: Supply Management 100: Induction heating roller device L1: External lead

Claims

1. An induction heating roller device for heat-treating sheet-like materials, the induction heating roller device comprising: Hollow cylindrical roller body; Multiple induction coils are arranged axially within the hollow of the roller body; A power supply circuit individually controls the power supplied to the plurality of induction coils; a cooling mechanism supplies refrigerant to the roller body to cool the roller body. The cooling mechanism control unit controls the supply of refrigerant to the cooling mechanism based on the load heat. The power supply circuit individually controls the power supplied to the plurality of induction coils in a manner that makes the temperature of the roller body reach a predetermined temperature and the heated object achieve a predetermined thickness distribution. When the load heat required to obtain the desired amount of deformation in the axial direction of the roller body is greater than the load heat taken away by the heated object from the roller body, the cooling mechanism control unit controls the supply of refrigerant based on the insufficient load heat, i.e., the difference between the two load heats.

2. An induction heating roller device, comprising: Hollow cylindrical roller body; Multiple induction coils are arranged axially within the hollow of the roller body; A power supply circuit individually controls the power supplied to the plurality of induction coils; a cooling mechanism supplies refrigerant to the roller body to cool the roller body; wherein the cooling mechanism individually supplies refrigerant to the portion of the inner surface of the roller body opposite to the plurality of induction coils.

3. The induction heating roller device as claimed in claim 1 or 2, wherein a jacketed chamber for sealing a gas-liquid two-phase heat medium is formed on the side peripheral wall of the roller body.

4. The induction heating roller device as claimed in claim 1 or 2, wherein the cooling mechanism supplies refrigerant into the hollow interior of the roller body.

5. The induction heating roller device as claimed in claim 3, wherein the cooling mechanism supplies refrigerant to a refrigerant flow channel formed on the side peripheral wall of the roller body further radially inward than the jacket chamber.

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