JPH10161446A - Induction heat generating roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the damage of an induction coil, to simplify structure and to shorten a rising time by setting the distance in a radial direction between the inner periphery of a hollow roller and the outer periphery of the induction coil, within a specific range. SOLUTION: The distance in the radial direction between the outer periphery 11 of the induction coil 10 and the inner periphery 12 of the hollow roller 1 is set 3-8mm. Power is supplied to the induction coil 10 from an external power source by a conductive harness 13. A fan is provided in a hollow roller supporting shaft 5, to be turned toward a central hole 3. Further, a temperature detecting member coming into contact with the coil 10 is provided in an induction coil supporting part 4 and the detection signal of the temperature detecting member is transmitted to a control means by a conductive harness 16, to control the working of the fan. When the distance in the radial direction between the outer periphery of the induction coil 10 and the inner periphery of the hollow roller 1 is >=3mm, the adverse influence of the radiation of heat from the hollow roller 1 can be prevented. When the distance is <=8mm, the efficiency of thermal conversion is never reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating roller used as a fixing roller in an image forming apparatus.

[0002]

2. Description of the Related Art Generally, this type of induction heating roller includes a hollow roller and a support member to which an induction coil is attached and which rotatably supports the hollow roller. By the way, such a device has a problem that the induction coil is disconnected or short-circuited and damaged due to high heat. In order to solve such a problem, there is one disclosed in Japanese Patent Application Laid-Open No. 58-209887, which is shown in FIG. 2, which will be described. In this induction heating roller, 31 is a hollow roller, 32 is a support member for the hollow roller, and has a solid core portion 34 on the outer periphery of which an induction coil 33 is attached. The hollow shaft portion 38 of the hollow roller 31 is rotatably supported by a support shaft 36 projecting from the surface via a bearing 37. A lead wire 39 having one end connected to the induction coil 33 is provided on the support shaft 36, and the lead wire 39 is led out of the support shaft 36 and connected to the power supply 40. Then, a jacket 41 is provided on the support member 32,
A cylindrical heat insulating material 42 is concentrically wound around the induction coil 33.

In such a device, a cooling medium is circulated in a jacket 41 to cool the support member 32 and the hollow roller 31 is cooled.
To prevent conduction heat from being transmitted to the induction coil 33,
On the other hand, by blocking the radiant heat and convective heat generated by the hollow roller 31 by the heat insulating material 42, the induction coil 33 is not exposed to such heat, and the above-described problem can be solved. .

[0004]

However, in this conventional example, the structure is complicated as described above, since the heat insulating material is wound around the induction coil and the jacket is provided on the support member. In addition, the use of a heat insulating material and a refrigerant increases the cost, and the use of the refrigerant causes heat to be taken away by the refrigerant at the time of start-up. There is.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional induction heating roller, to prevent the induction coil from being damaged, to have a simple structure and to be inexpensive, and to shorten the rise time. An object of the present invention is to provide an induction heating roller capable of shortening the start time of a copying operation.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises a hollow roller and a support member to which an induction coil is attached and which rotatably supports the hollow roller. In the induction heating roller described above, the invention according to claim 1 is characterized in that a radial distance between an inner peripheral surface of the hollow roller and an outer peripheral surface of the induction coil is 3 to 8 mm. is there.

According to a second aspect of the present invention, in the first aspect, the support member has a hollow cylindrical central shaft portion, and a blower fan for blowing air is provided inside the central shaft portion. It is characterized by having.

According to a third aspect of the present invention, in the second aspect of the present invention, a temperature detection member is mounted on the induction coil mounting portion of the support member, and the operation of the blower fan is controlled by the temperature detection member. It is characterized by having become.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in FIG. 1, reference numeral 1 denotes a mold release made of a magnetic material such as iron and formed of a Teflon resin, silicon rubber, fluorine rubber or the like (not shown) on the outer peripheral surface. The hollow roller 2 provided with the layer is a support member for the hollow roller 1, and the support member 2
And an induction coil support portion 4 and hollow roller support shafts 5 and 6 formed at both ends of the induction coil support portion 4 are provided. The hollow roller support shafts 5 and 6 are Thus, the hollow shaft portions 8, 9 of the hollow roller 1 are rotatably supported.

The induction coil supporting portion 4 supports the induction coil 10, and the radial distance between the outer peripheral surface 11 of the induction coil 10 and the inner peripheral surface 12 of the hollow roller 1 is 3 to 8 mm.
The induction coil 10 is energized from an external power supply (not shown) by an energizing harness 13, and a blower fan 14 is provided on one of the hollow roller support shafts 5 toward the center hole 3. The induction coil support 4 is provided with a temperature detecting member 15 that comes into contact with the induction coil 10, and a detection signal of the temperature detecting member 15 is transmitted to a control unit (not shown) by an energizing harness 16, and the air blowing fan
The operation of 14 is controlled.

In such an embodiment, the radial distance between the outer peripheral surface 11 of the induction coil 10 and the inner peripheral surface 12 of the hollow roller 1 is 3 mm or more. The adverse effect of radiation can be prevented, and since the distance is within 8 mm, the heat conversion efficiency by induction heating is not reduced.

A blower fan 14 is provided on the hollow roller support shaft 5 toward the center hole 3 of the support member 2 by a temperature detecting member 15 provided on the induction coil support portion 4 and in contact with the induction coil 10. It does not operate until a predetermined temperature is detected, and starts operating when a detection signal is output when the temperature exceeds the predetermined temperature, and the air blows through the center hole 3 of the support member 2 to support the air. The induction coil 10 is cooled through the member 2, thereby preventing the induction coil 10 from being heated to a high temperature, so that the induction coil 10 is not broken or short-circuited and damaged. . Further, at the time of rising, since the induction coil 10 is at a temperature equal to or lower than the predetermined temperature, the blower fan 14 does not operate, and unnecessary cooling work is not performed. Work start time is shortened.

[0013]

As described above, the present invention is directed to an induction heating roller including a hollow roller and a support member to which an induction coil is attached and which rotatably supports the hollow roller. According to the first aspect of the present invention, since the radial distance between the inner peripheral surface of the hollow roller and the outer peripheral surface of the induction coil is 3 to 8 mm, it is possible to prevent adverse effects due to heat radiation from the hollow roller. In addition to the above, the heat conversion efficiency due to the induction heating is not reduced, and the induction coil is prevented from being heated to a high temperature. However, there is an effect that it can be provided simply and at a low price.

According to a second aspect of the present invention, in the first aspect, the support member has a hollow cylindrical central shaft portion, and a blower fan for blowing air is provided inside the central shaft portion. According to a third aspect of the present invention, in the second aspect, a temperature detecting member is mounted on the induction coil mounting portion of the support member, and the operation of the blower fan is controlled by the temperature detecting member. The temperature of the induction coil is prevented from becoming high,
Also, since the induction coil is at a temperature equal to or lower than a predetermined temperature at the time of start-up, the blower fan does not operate, and unnecessary cooling work is not performed. In addition, there is an effect that the start-up time of the copying operation is shortened because the rise time is short.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the upper half of a conventional induction heating roller of the same type as the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Hollow roller 2 Support member 3 Center hole 4 Induction coil support part 5 Hollow roller support shaft 6 Hollow roller support shaft 7 Bearing 8 Hollow shaft part 9 Hollow shaft part 10 Induction coil 11 Outer peripheral surface 12 Inner peripheral surface 13 Electricity harness 14 Ventilation fan 15 Temperature detection member 16 Electrical harness

Claims (3)

[Claims] 1. An induction heating roller comprising: a hollow roller; and a support member to which an induction coil is attached and rotatably supporting the hollow roller, wherein an inner peripheral surface of the hollow roller and an outer periphery of the induction coil are provided. An induction heating roller, wherein a radial distance from the surface is 3 to 8 mm. 2. The induction heating roller according to claim 1, wherein the support member has a hollow cylindrical central shaft portion, and a blower fan for blowing air is provided inside the central shaft portion. 3. The induction heating device according to claim 2, wherein a temperature detecting member is mounted on the induction coil mounting portion of the support member, and the operation of the blower fan is controlled by the temperature detecting member. roller.