JP2002048131A - Heating rotor and heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such problems that thermal efficiency is low because of the escape of heat from the end portion of a fixing roller and a deflection of the fixing roller becomes large under applied pressure by a compression roller because of thin wall thickness of a heat generating part, thereby, there exists a possibility for a trouble during paper transportation or pictorial image irregularity to occur. SOLUTION: The rotor generates heat by electromagnetic induction under the action of generated magnetic flux from magnetic flux generating means, the interior of the rotor has a core part which is formed with material having high thermally insulative and heat resisting properties, and the rotor is supported freely rotatable with this core part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic (magnetic) induction heating type heating rotator and a heating apparatus, and more particularly, to a method in which a material to be heated is subjected to heat treatment, and the material to be heated is wrinkled, polished and formed on the surface. The present invention relates to a heating rotator and a heating device that are applied to heat-fix an unfixed image to a material to be heated.

[0002]

2. Description of the Related Art In a known image forming apparatus, a toner image (unfixed image) electrostatically formed on a material to be heated such as paper through a transfer process is heated and fixed to the material to be heated. Conventionally, there has been widely practiced means for passing a material to be gripped to hold a toner image between a pair of heating rollers and a pressure roller that are in pressure contact with each other, and applying heat and pressure to the toner image to heat and fix the toner image. ing.

FIGS. 9 and 10 show a typical example of a known electromagnetic (magnetic) induction heating type fixing device as one of the above means.

FIG. 9 is a cross-sectional view showing the structure of a conventional fixing device to which a heating device of the electromagnetic induction heating type is applied as a heat source, and FIG. 10 shows the arrangement in the longitudinal direction around the fixing roller in FIG. FIG. The induction generation heating method is an electromagnetic induction phenomenon (Faraday's law) in which magnetic flux changes when a metal crosses a magnetic field, and an eddy current flows through the metal in a direction that suppresses the movement of the metal due to the change in the magnetic flux. Used. When a current flows through a metal, heat is generated by the electrical resistance of the metal. An induction heating type fixing device fixes and fixes the toner image on the material to be heated using the heat.

In the fixing device, a magnetic flux generating means 4 is arranged along the outer diameter of the fixing roller 1 made of magnetic metal instead of a heat source such as a heater. The magnetic flux generating means 4 includes an exciting coil 5 and a core material (hereinafter referred to as a magnetic core).
6. The core 6 is preferably made of a material having a high magnetic permeability and a low residual magnetic flux density, such as ferrite or permalloy. The magnetic core 6 and the exciting coil 5 are supported by a holder 20.

The lines of magnetic force pass through the core 6 and the fixing roller.
The exciting coil 5 has a substantially elliptical shape in the longitudinal direction of the fixing roller 1 and is arranged along the outer surface of the fixing roller 1. The fixing roller 1 is also heated by the magnetic flux generated by each of the exciting coils 5. This alone
Although only about half of the heat generated by the fixing roller 1 is generated, the heating of the fixing roller 1 is performed without unevenness of the temperature by the rotation of the fixing roller 1.

The magnetic flux is generated in a direction in which the magnetic flux passes through the inside of the core 6 alternately. An AC power supply through which current alternates is suitable for input power from the power supply. There is a metal part of the fixing roller where the generated magnetic flux passes. Since the magnetic flux alternately passes through the metal part, the effect is the same as that of the metal crossing the magnetic flux, and heat is generated in the metal part.

As the metal of the fixing roller 1 serving as the heat generating portion, iron, nickel, cobalt, etc., which are ferromagnetic metals, are suitable. 9 and 10, the fixing roller 1 uses an iron-based alloy.

In the above fixing device, since the fixing roller itself is a heating element, power efficiency is higher than that of a fixing device using a known halogen heater. In general, the life of the magnetic flux generating means is longer than the life of the halogen heater, so that it does not become a consumable part. For that reason, it also plays a role in improving serviceability.

Further, since the magnetic flux generating means can smoothly change the electric power, it is said that measures against flicker of high frequency can be easily made. Such advantages have recently attracted attention as heat generation means.

The operation when the above fixing device is used in an image forming apparatus will be described.

A pressure roller 8 for pressing the fixing roller 1 to form a nip N is provided. The fixing roller 1 and the pressure roller 8 are pressed against each other and are rotatably supported. The pressure roller 8 is pressed against the fixing roller 1 by pressure means (not shown). The pressing means is generally configured using a spring and is loaded at about 2 to 100 kgf, and the width of the nip portion N is generally about 6 mm. The pressure load is a value set in consideration of the toner fixing property.

A toner release layer (not shown) is formed on the outer surface of the fixing roller 1 and is generally made of PTFE 10 to 50 μm or PFA.
The thickness is 10 to 50 μm. It is also known to use a rubber layer inside the toner release layer. The pressure roller 8 has a configuration in which a toner release layer 8c is provided on the outer periphery of an iron core 8a, similarly to the silicone rubber layer 8b and the fixing roller 1.

The fixing roller 1 receives the driving force from the gear 21 at the end and rotates in response to the driving force in the direction of arrow A, and accordingly the pressure roller 8 follows and rotates in the direction of arrow B.

At a transfer portion (not shown), a material S to be gripped to hold the electrostatically formed toner image
When the toner image is conveyed to the nip portion N from the direction of arrow C and passes through the nip portion along the transfer material conveyance path H including the conveyance guide 41, the heated toner image is melted and fixed to the material S to be heated and discharged outside the machine. Is done.

Further, separating claws 10 and 42 for suppressing the material S to be heated from being wound around the fixing roller 1 and the pressure roller 8 and separating the material S from the fixing roller 1 and the pressure roller 8 are provided. Further, a detecting means (thermistor) 11 for detecting the surface temperature of the fixing roller 1 is used.
The temperature control is performed so that the surface temperature is kept constant.

Further, in order to reduce the weight time, the thickness of the fixing roller 1 is reduced to reduce the heat capacity of the fixing roller.

Since the fixing roller 1 has thermal conductivity,
The heat escapes toward the end in the longitudinal direction, and the heat is further transmitted through the support member of the fixing roller 1, leading to a decrease in the heat on the surface of the fixing roller. For this purpose, the bearing of the support member of the fixing roller 1 is made of a member having high heat insulation and heat resistance in consideration of the effect of heat escaping toward the longitudinal end.

When the rotation speed of the fixing roller 1 is high, ball bearings 30a and 30b are used. At that time, the fixing roller 1 and the ball bearing 30
a, 30b (hereinafter, referred to as a bearing) are interposed between heat insulating bushes 50a, 50b having high heat resistance and heat resistance. This prevents the performance of the bearing from deteriorating due to heat. PPS resin / PB
T-based resins and polyamides are common.

The fixing roller disclosed in Japanese Patent Application Laid-Open No. 9-237676 has a configuration in which a magnetic layer is provided on the outer peripheral surface of a hollow roller made of a nonconductive, highly heat-insulating and heat-resistant rigid material. Heat is generated by heating. A member having high heat insulation and heat resistance is also used at the end of the fixing roller. This effectively prevents heat from escaping from the end of the fixing roller.

In the fixing roller disclosed in Japanese Patent Application Laid-Open No. 9-237676, a hollow roller made of a non-conductive, highly heat-insulating and heat-resistant rigid material is used with a certain thickness in order to increase mechanical strength.

In Japanese Patent Application Laid-Open No. 8-16005,
The gap between the core and the heat-generating part (magnetic metal part) is 0.00
1 to 10 mm is effective, and there is a case in which heat is generated as the distance is shorter.

The above Japanese Unexamined Patent Publication No. Hei 9-237676 is far from good in terms of power consumption efficiency, judging from the relationship between the distance between the core and the heat generating part in the above Japanese Unexamined Patent Publication No. Hei 8-16005. The reason is that there is a layer of a non-conductive, highly heat-insulating, heat-resistant, rigid material between the core portion and the heat generating portion.
Therefore, if the gap between the core portion and the heat generating portion is large, the magnetic flux density generated from the magnetic flux generating means becomes small in the heat generating portion. In Japanese Unexamined Patent Publication No. 9-237676, a gap (distance) between the magnetic flux generating means and the magnetic portion (outer peripheral surface portion), which is a heat generating portion, is increased because there is a layer of a nonconductive, highly heat-insulating, heat-resistant, rigid material. . This inevitably results in poor heat generation efficiency.

[0024]

As described above,
The conventional electromagnetic induction heating type fixing device has the following problems. a) Since the thickness of the heat generating portion of the fixing roller is thin, the amount of deflection of the fixing roller increases due to the pressing force of the pressure roller.
As a result, there is a possibility that paper conveyance troubles and image unevenness may occur. b, there is a device in which a magnetic flux generating means is provided inside a hollow roller and a magnetic layer is provided on the outer peripheral surface of the hollow roller to constitute a fixing roller to increase mechanical strength, as disclosed in JP-A-9-23767. As described in Japanese Patent Application Laid-Open No. 8-16005, there has been a problem that heat generation efficiency is deteriorated.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to improve the heat generation efficiency and increase the mechanical strength of a fixing roller. Further, as a countermeasure against the problem of heat escaping from the end of the fixing roller, a heat insulating bush is provided on the support of the fixing roller. Another object of the present invention is to solve the problems of increasing the mechanical strength of the thin fixing roller and releasing heat from the end of the fixing roller. It is another object of the present invention to reduce the space and cost by designing the supporting portion of the fixing roller compact.

[0026]

According to the present invention, there is provided a heating rotator and a heating apparatus having the following constitution. (1) A rotating body that generates electromagnetic induction heat by receiving the action of the magnetic flux generated by the magnetic flux generating means. The inside of the rotating body has a core formed of a material having high heat insulation and heat resistance. A heating rotator, wherein the rotator is rotatably supported. (2) A rotating body that generates electromagnetic induction by receiving the action of the magnetic flux generated by the magnetic flux generating means, and the inside of the rotating body has a double structure of a material having high heat insulation and heat resistance and a material having high rigidity. The core portion is formed, and the layer in contact with the rotating body is made of a material having high heat-insulating and heat-resistant properties, and the rotating body is rotatably supported by the core having the high heat-insulating and heat-resistant property. Heating rotating body. (3) A rotating body that generates electromagnetic induction by receiving the action of the magnetic flux generated by the magnetic flux generating means, and the inside of the rotating body has a double structure of a material having high adiabatic heat resistance and a material having high rigidity. A layer in contact with the rotating body is formed of a material having high heat-insulating and heat-resistant properties, and the rotating body is rotatably supported by the core having the high rigidity property. Rotating body. (4) The outer diameter of the core portion at a position where the rotating body according to any one of (1), (2), and (3) is rotatably supported is different from the outer diameter of the rotating body. And the heating rotator. (5) A hollow rotating body that generates electromagnetic induction by receiving the action of the magnetic flux generated by the magnetic flux generating means, and has a core formed of a substance having high heat insulation and heat resistance inside both ends of the hollow rotating body. And a hollow rotating body rotatably supported by the core. (6) A hollow rotating body that generates electromagnetic induction by receiving the action of the magnetic flux generated by the magnetic flux generating means. The core portion is formed with a double structure of a substance having, and the layer in contact with the rotating body is a substance having high heat insulation and heat resistance properties,
A heating rotator, wherein the rotator is rotatably supported by the core having the property of high heat insulation and heat resistance. (7) A hollow rotating body that generates electromagnetic induction heat by the action of the magnetic flux generated by the magnetic flux generating means. The core portion is formed with a double structure of a substance having, and the layer in contact with the rotating body is a substance having high heat insulation and heat resistance properties,
A heating rotator, wherein the rotator is rotatably supported by the core having high rigidity characteristics. (8) The outer diameter of the core at a position where the rotating body according to any one of (5), (6) and (7) is rotatably supported is different from the outer diameter of the hollow rotating body. A heating rotator. (9) Heating, wherein the core having high rigidity characteristics of the rotating body according to any one of (2), (3), (6) and (7) is a hollow member. Rotating body. (10) A heating rotator provided with an air escape hole in a core of the rotator according to any one of (5), (6) and (7). (11) (1), (2), (3), (5), (6), (7)
5. A heating rotator, wherein a toner release layer is provided on an outer peripheral surface of the rotator according to any one of the above. (12) (1), (2), (3), (5), (6), (7)
A heating rotor, wherein the hollow rotor and the core are joined by press-fitting. (13) A heating rotator wherein the ferromagnetic portion of the rotator according to any one of (1), (2) and (3) is provided by plating. (14) A material having high heat-insulating and heat-resistant properties provided inside both ends of the hollow rotating body according to any one of (5), (6) and (7), on the center side of the rotating body. The end position in the longitudinal direction is larger than the center in the longitudinal direction from both ends of the pressure roller that is in pressure contact with the rotating body, so that a substance having high heat insulation and heat resistance properties is arranged at a position facing the pressure roller. A heating rotator characterized by being performed. (15) (1), (2), (3), (5), (6), (7)
The material having the property of high heat insulation and heat resistance according to any one of the above uses a rigid material having high heat insulation heat resistance and high mechanical strength such as PPS resin, PBT resin, polyamide resin, and ceramic. A heating rotator, characterized in that: (16) (1), (2), (3), (5), (6), (7)
The magnetic flux generating means according to any one of the preceding claims, comprising a magnetizing core and an exciting coil. (17) The heating rotator according to any one of (1) to (14), wherein the rotator is formed of a material having ferromagnetic properties. (18) The heating rotator according to any one of (1) to (14), wherein a layer of a material having ferromagnetic properties is formed on an outer peripheral surface of the base. (19) (1), (2), (3), (5), (6), (7)
The magnetic flux generating means according to any one of the preceding claims, wherein the magnetic flux generating means is disposed close to and opposed to the rotating body. (20) In a heating device having a heating rotator for heating the material to be heated introduced and conveyed to the heating unit by electromagnetic induction heat generated by the action of the magnetic flux generated by the magnetic flux generating means, the heating rotator may be configured as described in (1). (18) A heating device using the heating rotator according to any one of (18).

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. First Embodiment FIGS. 1 and 2 show a first embodiment of the present invention. The same parts as those of the conventional example shown in FIGS. . FIG. 1 is a sectional configuration view of a heating device according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view showing a longitudinal arrangement around a fixing roller as a rotating body which is a component of the heating device of FIG. Yes, the fixing roller 1, the coil 5, the pressure roller 8, the side plates 33a and 33b, and the bearings 30a and 30b are shown so that the longitudinal relationship can be understood.

Although the entire fixing roller 1 may be made of a ferromagnetic material, the illustrated example has a structure in which a ferromagnetic layer 3 is provided on the surface of a highly heat-insulating heat-resistant shaft core 2 as a base. The shaft core 2 having high heat insulation and heat resistance is provided on the side plates 33a, 33b with the bearings 30a,
30b.

FIG. 5A is an enlarged image diagram of the fixing roller 1. The central portion of the fixing roller 1 is a shaft core 2 having high heat insulation and heat resistance. A ferromagnetic layer 3 and a toner release layer R are provided on the outer peripheral surface. The toner release layer R is composed of 10 to 50 μm of PTFE or 10 to 50 μm of PFA as in the conventional example. Further, a rubber layer may be used inside the toner release layer R.

The shaft core 2 having high heat insulation and heat resistance is made of PPS resin.
A solid rod made of a rigid material having high heat resistance and high mechanical strength such as PBT resin, polyamide resin, and ceramic is used.

FIG. 5D shows the solid portion inside the fixing roller of the first embodiment in a rib shape. As a result, it is possible to increase rigidity, reduce weight and reduce material costs.

Next, a method of manufacturing the fixing roller 1 will be described.

As a material for the ferromagnetic layer, a metal such as iron, nickel, or cobalt is preferably used. By using a ferromagnetic metal (a metal having a high magnetic permeability), the magnetic flux generated from the magnetic flux generating means can be more restricted in the ferromagnetic metal. That is, the magnetic flux density can be increased. As a result, an eddy current is efficiently generated on the surface of the ferromagnetic metal to generate heat.

On the other hand, in the case of a metal having a low magnetic permeability such as aluminum, the magnetic flux cannot be confined in the metal, so that the magnetic flux density is small and a slight current is not generated. Is not good.

In order to form the ferromagnetic layer 3, the metal of the ferromagnetic layer 3 can be formed on the surface of the highly heat-insulating and heat-resistant shaft core 2 as a substrate by surface treatment. The molding method may be a known surface treatment such as plating, sputtering, or vapor deposition.

In order to provide the ferromagnetic metal layer with a certain thickness (thickness equal to or greater than the skin depth), a surface treatment by plating is particularly preferable. In the plating process, electric nickel plating has a high magnetic permeability and is suitable in terms of cost. A hollow pipe made of a ferromagnetic material and a solid rod having high heat insulation and heat resistance may be pressed and integrated. The ferromagnetic layer 3 can also be formed by drawing a nickel or iron hollow pipe simultaneously with a material having high heat insulation and heat resistance, such as drawing.

When a ferromagnetic layer 3 formed on the surface of a hollow pipe is used, there is a possibility that the fixing force between the shaft core 2 and the hollow pipe is weakened due to durability and the like. Thus, FIG. 6 shows the use of screws 52a and 52b to prevent the hollow pipe and the shaft core from coming off.

Further, a projection may be provided on the solid rod, and a mechanism for preventing the hollow pipe from slipping off in the rotation direction and the longitudinal direction may be provided by a hole fitted to the projection. Of course, the configuration of the projection and the fitting may be reversed. In addition, a groove and a fitting portion may be provided at the end in the longitudinal direction to prevent rotation in the rotation direction. The effect of the present invention is not changed by such a slip-out prevention configuration.

Next, the thickness of the ferromagnetic layer of the present invention will be described in detail.

Most of the eddy current flows near the surface of the ferromagnetic layer due to the skin effect with a skin depth δ and a skin resistance Rs. The skin resistance Rs is represented by using an angular frequency ω, a magnetic permeability μ, and a specific resistance value ρ.

[0041]

(Equation 1)

Can be expressed as follows. Here, I is the eddy current.

Thus, it can be seen that it is effective to determine the thickness of the ferromagnetic layer based on the skin depth of the eddy current. Even when the thickness of the ferromagnetic layer is smaller than the skin depth, the ferromagnetic layer generates heat, but is inefficient because the leakage magnetic flux increases. Conversely, when the thickness of the ferromagnetic layer is too thick than the skin depth, the ferromagnetic layer generates heat. However, since the portion that is too thick than the skin depth hardly generates heat, the heat capacity increases, which is not efficient.

Therefore, in the present invention, the thickness of the ferromagnetic layer is set to be substantially equal to or greater than the skin depth of the eddy current. As described above, the thickness is a value that changes depending on the type of metal, frequency, and the like, and thus does not become a certain value. When determining the thickness, it is preferable to determine the thickness in consideration of the method of manufacturing the fixing roller.

This magnetic layer becomes a heat generating portion by the magnetic field generated by the magnetic flux generating means 4. The temperature of the fixing roller is controlled to a fixing-possible temperature by the heat-generating portion in the same manner as in the conventional example, and the toner image is fixed.

With the fixing roller 1 described above, the mechanical strength can be improved as compared with the conventional thin fixing roller 1. Escape of heat in the longitudinal direction of the magnetic layer can be prevented by the shaft core 2 having high heat insulation. Since the shaft core portion 2 supported by the bearings 30a and 30b is made of a material having high heat insulation and heat resistance, the heat insulating bushes 50a and 50b as in the conventional example are not required. This enables a compact design that achieves space saving and low cost.

Next, the image forming operation of the first embodiment will be described. (See FIG. 2) The operation is almost the same as in the conventional example.

The fixing roller 1 is rotated in the direction of arrow A by receiving the driving force from the gear 21 at the end, and the pressure roller 8 is also driven to rotate in the direction of arrow B accordingly. The pressure roller 8 has a silicone rubber layer 8b on the outer periphery of an iron core 8a.
And a configuration in which a toner release layer 8c is provided similarly to the fixing roller 1.

A heated material S carrying a toner image electrostatically formed at a transfer portion (not shown) moves along a conveying path H along an arrow C.
When the toner image is conveyed from the direction to the nip portion N and passes through the nip portion, the heated toner image is melted and fixed to the material to be heated and discharged outside the machine. In addition, a separation claw 10 for suppressing the material S to be heated from being wound around the fixing roller 1 and separating the heated material S from the fixing roller 1 is provided. Further, a temperature control is performed by a detecting means (thermistor) 11 for detecting the surface temperature of the fixing roller 1 so that the surface temperature of the fixing roller 1 is kept constant.

The core member is preferably made of a material having a high magnetic permeability and a low residual magnetic flux density, such as ferrite or permalloy.
There is no particular limitation as long as it can generate a magnetic flux. Further, the shape of each core 6 is not specified. Second Embodiment Next, a second embodiment will be described.

FIG. 3 is a view showing a second embodiment. The shaft core of the fixing roller 1 having high heat insulation and heat resistance is formed by pressing or integrally molding a metal shaft 22 into a member 23 of high heat insulation and heat resistance. It is a heavy structure. The metal shaft 22 may be a material generally used as a shaft, such as an iron alloy. The relationship between the thickness of the highly heat-insulating and heat-resistant material portion 23 and the diameter of the metal shaft 22 is determined based on the heat-insulating performance of the highly heat-insulating and heat-resistant portion and the amount of deflection of the fixing roller 1. To reduce the amount of deflection of the fixing roller 1, the diameter of the metal shaft may be increased.

FIG. 5B shows a cross section of the fixing roller according to the second embodiment.
The space between the portions is a material portion 23 having high heat insulation and heat resistance. Accordingly, in the second embodiment, the amount of deflection of the fixing roller 1 can be reduced even when the pressing force is increased as compared with the first embodiment, and the second embodiment is also applicable to an image forming apparatus in which the conveying speed of the material S to be heated is high. .

Gear 21 for driving fixing roller 1
Is formed integrally with the high heat-insulating and heat-resistant material portion 23, so that the assemblability is improved and the cost is reduced. In other embodiments, even if the gear 21 and the shaft portion are integrally formed, the effect of the present embodiment does not change.

FIG. 5E shows a second embodiment in which the high heat-insulating and heat-resistant portion inside the fixing roller is formed in a rib shape, thereby providing rigidity, lightening, and reduction in material cost. ing. Third Embodiment FIG. 4 is a view showing a third embodiment, in which the fixing roller 1 uses the metal shaft 22 of the second embodiment with bearings 30a and 30b.
It is a configuration supported by. In this configuration, the bearing 30
a and 30b can be small in diameter. In addition, the material of the material portion 23 having high heat insulation and heat resistance can be reduced. Therefore, cost reduction and space saving can be achieved. Fourth Embodiment FIG. 6 shows a fourth embodiment, in which a fixing roller 1 uses a hollow metal pipe for a magnetic layer 3 and both ends thereof are closed with high heat-insulating and heat-resistant material portions 23a and 23b. It is. Highly heat-insulating and heat-resistant material portion 23 serving as shaft cores at both ends of fixing roller 1
a and 23b are supported by bearings 30a and 30b, respectively.

Each of the magnetic metal pipes 3 is manufactured by press-fitting a material portion 23a, 23b having high heat insulation and heat resistance. Moreover, as described in the first embodiment, the magnetic metal part and the rotation stopping part of the high heat insulating and heat resistant material parts 23a and 23b are provided. The high heat-insulating and heat-resistant material parts 23a and 23b are shown in FIG.
As shown in (2), by press-fitting so as to be inside (center) from the end of the pressure roller 8, the pressing force from the pressure roller 8 can be received by the highly heat-insulating and heat-resistant material portions 23a and 23b. ing.

Since both ends of the fixing roller 1 are closed by high heat-insulating and heat-resistant material portions 23a and 23b each having a shaft core, a space is formed inside the fixing roller 1. Due to the heat generation, the air inside expands. In order to release the influence, a small hole 25 is formed in at least one of the material portions 23a and 23b. Fifth Embodiment FIG. 7 shows a fifth embodiment, in which a high heat-insulating and heat-resistant material portion 23a supporting the fixing roller 1 of the fourth embodiment is used.
The outer diameter of the support portion 23b is smaller than the outer diameter of the hollow pipe portion 3 made of magnetic metal. The effect is the same as the diameter reduction of the bearing of the third embodiment, so that space saving and cost reduction can be achieved. Sixth Embodiment FIG. 8 shows a sixth embodiment, in which high heat-insulating and heat-resistant material portions 23a and 23 supporting the fixing roller 1 of the fourth embodiment are shown.
This is a configuration in which a hollow shaft 22 'connecting b is provided. High heat-insulating and heat-resistant material portion 23a that closes both ends of magnetic metal pipe 3,
23b and the hollow shaft 22 'are formed integrally. The cross section is as shown in FIG. Even if the hollow shaft 22 'is a solid shaft, the effect does not change. However, the hollow shaft 22 'is better for reducing the material cost and the weight of the fixing device. Further, the fourth, fifth, and sixth embodiments also greatly contribute to the weight reduction of the fixing roller 1.

In each of the above embodiments, the heating device having the heating rotator of the present invention is applied to a fixing device for heating and fixing an unfixed image formed on the surface of the material to be heated to the material to be heated. Although the case has been described, the heating device of the present invention can be applied to, for example, flattening and polishing of a material to be heated.

[0058]

As described above, according to the present invention, there is provided a rotating body which generates electromagnetic induction heat under the action of the magnetic flux generated by the magnetic flux generating means. Since the core is formed of a substance and the rotor is rotatably supported by the core, heat escaping from the end of the rotor can be suppressed. This has the effect of using heat efficiently and contributing to energy saving.

Further, since the inside of the rotating body has a dual structure of a material having high heat insulation and heat resistance and a material having high rigidity, the mechanical strength of a thin rotating body can be improved.
This has the effect of contributing to the elimination of the adverse effects of deflection.

In addition, since the diameter of the supporting portion of the rotating body is reduced, materials having high heat insulation and heat resistance can be reduced, which contributes to cost reduction and space saving.

Further, since the end of the rotating body is configured to be supported with high heat insulation and heat resistance, it is possible to contribute to cost reduction by reducing the weight of the rotating body and reducing the material of high heat insulation and heat resistance.

Further, since the rotating body is hollow, there is an effect that it is possible to contribute to weight reduction and cost reduction.

Also, in a heating apparatus having a rotating body for heating the material to be heated introduced and conveyed to the heating section by generating electromagnetic induction by the action of the magnetic flux generated by the magnetic flux generating means, the magnetic flux is opposed to the rotating body. A generator is disposed, and the inside of the rotating body is formed with a core having a high heat-insulating and heat-resistant property, and the rotating body is rotatably supported by the core, so that heat loss is generated. And the heat treatment of the material to be heated can be performed efficiently.

[Brief description of the drawings]

FIG. 1 is a sectional configuration diagram of a magnetic flux generation unit and a fixing roller according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing an arrangement of the fixing roller in FIG. 1 in a longitudinal direction.

FIG. 3 is a sectional configuration diagram of a magnetic flux generation unit and a fixing roller according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional configuration diagram of a magnetic flux generating unit and a fixing roller according to a third embodiment of the present invention.

FIG. 5 is a cross-sectional view of a part of various fixing rollers.

FIG. 6 is a cross-sectional configuration diagram of a magnetic flux generation unit and a fixing roller according to a fourth embodiment of the present invention.

FIG. 7 is a cross-sectional configuration diagram of a magnetic flux generation unit and a fixing roller according to a fifth embodiment of the present invention.

FIG. 8 is a sectional view of a magnetic flux generating unit and a fixing roller according to a sixth embodiment of the present invention.

FIG. 9 is a cross-sectional configuration diagram of a conventional magnetic flux generation unit and a fixing roller.

FIG. 10 is a longitudinal sectional view showing a longitudinal arrangement of the fixing roller of FIG. 9;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixing roller (rotating body) 2 Highly heat-insulating and heat-resistant shaft core part 3 Ferromagnetic layer 4 Magnetic flux generating means 5 Exciting coil 6 Core 8 Pressure roller 22 Metal shaft 23 (23a, 23b) Highly heat-insulating and heat-resistant material part N Nip part 30a, 30b Bearing 33a, 33b Side plate

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 6/14 H05B 6/14 (72) Inventor Atsuyoshi Abe 3-30-2 Shimomaruko 3-chome, Ota-ku, Tokyo Non-corp. F-term (reference) AD32 AD35 CD52

Claims (20)

[Claims] 1. A rotating body which generates electromagnetic induction by receiving the action of a magnetic flux generated by a magnetic flux generating means. The rotating body has a core formed of a material having high heat insulation and heat resistance. A heating rotator that rotatably supports the rotator. 2. A rotating body which generates electromagnetic induction by receiving the action of a magnetic flux generated by a magnetic flux generating means. The inside of the rotating body is composed of a material having high heat insulation and heat resistance and a material having high rigidity. A core having a double structure is formed, and a layer in contact with the rotating body is made of a material having high heat-insulating and heat-resistant properties, and the rotating body is rotatably supported by the core having high heat-insulating and heat-resistant properties. Characterized heating rotator. 3. A rotating body which generates electromagnetic induction by receiving the action of magnetic flux generated by a magnetic flux generating means. The inside of the rotating body is composed of a material having high heat insulation and heat resistance and a material having high rigidity. The core part is formed in a double structure, the layer in contact with the rotating body is made of a material having high heat-insulating and heat-resistant properties, and the rotating body is rotatably supported by the core part having the high rigidity property. Heating rotating body. 4. An outer diameter of a core portion at a position for rotatably supporting the rotating body according to any one of claims 1, 2, and 3, is different from an outer diameter of the rotating body. Heating rotating body. 5. A hollow rotating body which generates electromagnetic induction heat under the action of a magnetic flux generated by a magnetic flux generating means, and has a core portion made of a material having high heat insulation and heat resistance inside both ends of the hollow rotating body. And a hollow rotating body is rotatably supported by the core portion. 6. A hollow rotating body which generates electromagnetic induction heat under the action of a magnetic flux generated by a magnetic flux generating means. Inside the hollow rotating body, a material having high adiabatic heat resistance and a material having high rigidity are provided. A core having a double structure of a material having the following characteristics is formed, and a layer in contact with the rotating body is made of a material having high heat-insulating and heat-resistant properties. A heating rotator supported rotatably. 7. A hollow rotating body which generates electromagnetic induction by receiving the action of a magnetic flux generated by a magnetic flux generating means, wherein a material having high heat insulation and heat resistance properties and a high rigidity are provided inside both ends of the hollow rotating body. A core part is formed by a double structure of a substance having the following characteristics, and a layer in contact with the rotating body is made of a substance having high heat-insulating and heat-resistant properties, and the rotating body is rotatable with the core part having the high rigidity property. A heating rotator supported on a rotator. 8. An outer diameter of a core portion at a position for rotatably supporting a rotating body according to any one of claims 5, 6, and 7, is different from an outer diameter of a hollow rotating body. And the heating rotator. 9. A heating rotator according to claim 2, wherein the core having high rigidity characteristics of the rotator according to any one of claims 2, 3, 6, and 7 is a hollow member. 10. A heating rotator wherein an air escape hole is provided in a core of the rotator according to any one of claims 5, 6, and 7. 11. A heating rotator wherein a toner release layer is provided on an outer peripheral surface of the rotator according to any one of claims 1, 2, 3, 5, 6, and 7. 12. A heating rotator wherein the hollow rotator and the core according to any one of claims 1, 2, 3, 5, 6, and 7 are joined by press-fitting. . 13. A heating rotator according to claim 1, wherein the ferromagnetic portion of the rotator is provided by plating. 14. A longitudinal direction of a substance having high heat-insulating and heat-resistant properties provided at both ends of a hollow rotating body according to any one of claims 5, 6, and 7 on the center side of the rotating body. By setting the end position of the material to be larger than the center in the longitudinal direction from both ends of the pressure roller in pressure contact with the rotating body, a substance having high heat insulation and heat resistance properties is arranged at a position facing the pressure roller. A heating rotator, characterized in that: 15. The substance having high adiabatic heat resistance according to any one of claims 1, 2, 3, 5, 6, and 7,
A heating rotator characterized by using a rigid material having high heat resistance and high mechanical strength such as PS resin, PBT resin, polyamide resin and ceramic. 16. A heating rotor according to claim 1, wherein the magnetic flux generating means comprises an exciting coil and a magnetic core. 17. A heating rotator according to claim 1, wherein the rotator is made of a material having ferromagnetic properties. 18. A heating rotator according to any one of claims 1 to 14, wherein a layer of a material having ferromagnetic properties is formed on an outer peripheral surface of the substrate. . 19. A heating rotator wherein the magnetic flux generating means according to any one of claims 1, 2, 3, 5, 6, and 7 is disposed close to and opposed to the rotator. 20. A heating apparatus having a heating rotator for heating an object to be heated introduced and conveyed to a heating unit by generating electromagnetic induction by the action of magnetic flux generated by a magnetic flux generating means, wherein the heating rotator is used as the heating rotator. A heating apparatus using the heating rotator according to any one of claims 1 to 18.