JP4728123B2 - Heating roll device - Google Patents

Description

  The present invention relates to a heating roll apparatus, and more particularly to a heating roll apparatus that can heat a heating roll with a uniform temperature distribution and has little leakage magnetic flux and excellent heating efficiency.

2. Description of the Related Art Conventionally, there has been known a heating roll device in which an excitation coil is installed in an internal space of a cylindrical heating roll, and an induction current is caused to flow through the heating roll by the excitation coil so that the heating roll is heated to a high temperature. Examples of the excitation coil include a loop coil having a coil axis orthogonal to the axial direction of the heating roll (see, for example, Patent Documents 1 and 2), and a spiral coil having a turning axis in the axial direction of the heating roll (for example, (See Patent Document 3).
JP 2000-150131 A JP 2003-215594 A JP 2003-330291 A

The conventional electromagnetic induction heating type heating roll device has a configuration in which the entire exciting coil is accommodated in the internal space of a cylindrical heating roll.
However, this configuration has a problem that the temperature distribution in the circumferential direction and the length direction of the heating roll is biased and a problem that the leakage magnetic flux is large.
SUMMARY OF THE INVENTION An object of the present invention is to provide a heating roll device that can heat a heating roll with a uniform temperature distribution and has little leakage magnetic flux and excellent heating efficiency.

In a first aspect, the present invention provides a cylindrical rotating heating roll, a bobbin inserted into the heating roll and having a circumferential surface concentric with the heating roll and not rotating, and a circumference of the bobbin A plurality of inner conductors fixed at a uniform density on the surface and extending in the axial direction of the heating roll, and an exciting coil comprising an outer conductor disposed in an outer space of the heating roll and serving as a return path for the plurality of inner conductors. Provided is a heating roll device comprising the heating roll device.
In the heating roll device according to the first aspect, since a plurality of inner conductors are fixed to the circumferential surface of the bobbin with a uniform density, local magnetic flux saturation does not occur and the heating roll is heated with a uniform temperature distribution. I can do it. Moreover, since the heating roll exists in the coil, the leakage magnetic flux is reduced, and the space where the magnetic flux density is highest is obtained, so that the heating efficiency can be improved.

  According to the heating roll device of the present invention, it is possible to heat the heating roll with a uniform temperature distribution, and there is little leakage magnetic flux, and heating efficiency can be improved.

  Hereinafter, the present invention will be described in more detail with reference to embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a plan view illustrating the heating roll device 10 according to the first embodiment.
This heating roll device 10 has a cylindrical heating roll 1 that is supported so as to be rotated by a rotary support tool 2, a circumferential surface that is inserted into the heating roll 1 and concentric with the heating roll 1, and is fixedly supported. A bobbin 3 supported so as not to rotate by the tool 4, and a plurality of inner conductors 5 a and heating rolls 1 fixed to the circumferential surface of the bobbin 3 with equal density and extending in the axial direction (longitudinal direction) of the heating roll 1. And an exciting coil 5 composed of an outer conductor 5b which is disposed in the outer space and serves as a return path for the plurality of inner conductors 5a.

FIG. 2 is a side view showing the heating roll device 10.
There is a gap 7 between the heating roll 1 and the bobbin 3.

  The exciting coil 5 is a loop coil having a coil axis orthogonal to the axial direction of the heating roll 1. By passing a high frequency (for example, 20 kHz to 50 kHz) current through the exciting coil 5, an induced current flows through the heating roll 1 to generate heat, resulting in a high temperature (for example, 200 ° C.).

  The heat transfer belt 6 is an endless belt that transfers the heat of the heating roll 1 that has reached a high temperature to a fixing roll of a fixing device of an image forming apparatus such as a printer or a copying machine.

The heating roll 1 is made of a ferromagnetic material (for example, iron) that is easily heated by electromagnetic induction.
The bobbin 3 is made of a heat-resistant material (for example, a ceramic having heat resistance, a glass baked product, a liquid crystal polymer that is a heat-resistant resin, or a phenol resin).
The inner conducting wire 5a and the outer conducting wire 5b are conducting wires (for example, magnet wires) through which a high-frequency current easily flows.

FIG. 3 is a plan view of the bobbin 3 to which the inner conductor 3a is fixed.
After inserting the bobbin 3 into the heating roll 1, the exciting coil 5 can be configured by connecting the inner conductor 3a to the outer conductor 5b.

  In the heating roll device 1, since the plurality of inner conductors 5 a are fixed to the circumferential surface of the bobbin 3 with an equal density, local magnetic flux saturation does not occur, and the temperature distribution is uniform over a wide range of the heating roll 1. Can generate heat. Moreover, since the heating roll 1 exists inside the exciting coil 5, the leakage magnetic flux can be reduced and the heating efficiency can be improved. Further, since the leakage magnetic flux can be reduced, the core for the magnetic shield can be reduced, and the configuration and cost can be reduced.

  The heating roll device of the present invention can be used as a heat source of a fixing device of an image forming apparatus such as a printer or a copying machine.

It is a top view which shows the heating roll apparatus concerning Example 1. FIG. It is a side view which shows the heating roll apparatus concerning Example 1. FIG. It is a top view of the bobbin 3 which fixed the inner side conducting wire 3a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating roll 2 Rotating support 3 Bobbin 4 Fixed support 5 Excitation coil 5a Inner conductor 5b Outer conductor 6 Heat transfer belt 7 Space | gap 10 Heating roll apparatus

Claims (1)

A cylindrical rotating heating roll; a bobbin which is inserted into the heating roll and has a circumferential surface concentric with the heating roll and which does not rotate; and is fixed to the circumferential surface of the bobbin with an equal density and A heating roll device comprising: a plurality of inner conductors extending in an axial direction of the heating roll; and an exciting coil that is disposed in an outer space of the heating roll and includes an outer conductor serving as a return path for the plurality of inner conductors. .

Images