JP2000150112A - Heating roller - Google Patents

Abstract

(57) [PROBLEMS] To prevent a fire from occurring in a heating roller 5 used for a belt fixing device in an electrophotographic image forming apparatus and to prevent damage to the configuration. SOLUTION: A planar heating element 152 is arranged in contact with an inner peripheral surface of an aluminum straight cylindrical heating roller body 151,
The sheet heating element 152 is provided with a temperature fuse,
When it reaches an abnormally high temperature of ~ 330 ° C, it melts and shuts off the power supply, preventing smoke and carbonization and avoiding fire. Journal 2 fixed to both ends of heating roller body 151
In the third flange 175 and the journal shaft 176,
An air hole communicating with the outside is provided to prevent the flange of the journal from being detached from the end of the heating roller body due to the expansion / contraction of air in the internal space of the heating roller body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt fixing device used in an image forming apparatus such as an electrophotographic copying machine, a printer and a facsimile machine, and a heating roller suitable for various other industrial uses. Furthermore, the present invention relates to a belt wrapping device such as a belt fixing device using the heating roller, and further relates to a heating roller and a sheet heating element that can be used for other purposes.

[0002]

2. Description of the Related Art A typical prior art is shown in FIG.
In a belt fixing device of an electrophotographic image forming apparatus, an endless belt 272 is wound between a heating roller main body 266 and another roller (not shown). A recording paper having a toner image is sandwiched between the belt 272 and a pressure roller which is elastically pressed against the belt 272,
The toner image is heated and fixed on the recording paper. Heating roller body 2
The halogen lamp 267 is inserted into the inside 66, and an annular space 271 is formed between the inner peripheral surface of the journal shaft 270 and the outer peripheral surface of the halogen lamp 267.

In the prior art in which the heating roller body 266 is heated by the halogen lamp 267 shown in FIG. 34, the outer peripheral surface of the heating roller body 266 is suitable for heat fixing from the time when power supply to the halogen lamp 267 is started. Therefore, in order to perform the heating and fixing at an arbitrary time, it is necessary to always perform preheating and to be in a standby state. There is a relatively large distance between the inner peripheral surface of the heating roller main body 266 and the outer peripheral surface of the halogen lamp 267. For these reasons, the prior art has a problem that the power consumption is large and the energy saving effect is low. Further, there is a problem that the temperature distribution on the outer peripheral surface of the heating roller main body 266 heated by the halogen lamp 267 is non-uniform, the surface temperature varies greatly, and the image fixing quality is low.

Further, an annular space 27 between the inner peripheral surface of the journal shaft portion 270 and the outer peripheral surface of the halogen lamp 267 is provided.
The presence of No. 1 results in large heat dissipation, remarkable temperature diffusion, and inferior heat retention, as described below with reference to FIGS. 32 and 33.

A typical prior art for solving the problem of the prior art shown in FIG. 34 is disclosed in Japanese Patent Application Laid-Open No. 62-150.
368 is a heat fixing roll disclosed in US Pat. An insulating layer is deposited on the inner peripheral surface of the aluminum cylinder, a resistance coating layer is deposited on the insulating layer, and the cylinder is heated by being energized. A flange is fixed to both ends of the cylindrical body, and a journal shaft portion supported by a bearing is provided on the flange. An electrode shaft is inserted coaxially into the journal shaft portion, and the electrode shaft has a resistance inside the cylindrical body. Each is connected to a coating layer. A brush provided at a fixed position slides on the electrode shaft, and power is supplied. Since the cylindrical body is heated by the heat generated by the resistance coating layer, the cylindrical body can be heated to a high temperature suitable for fixing in a short time as compared with a conventional configuration in which an elongated halogen lamp is inserted. In addition, the heat dissipation is suppressed by closing both ends of the cylindrical body, the temperature of the cylindrical body is kept stable, and the thermal efficiency is improved.

[0006] In this prior art, when the temperature of the resistance coating layer becomes abnormally high, the insulating layer and the like may emit smoke, carbonize, and lose insulation, thereby causing a fire. Furthermore, in this prior art, since both ends of the cylindrical body are closed and sealed by the flange and the electrode shaft as described above, the expansion / contraction of the air in the cylindrical body internal space due to the temperature change is repeated,
There is a problem that the flange may be detached from both ends of the cylindrical body.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heating roller capable of preventing an abnormal rise in temperature, improving safety, and preventing damage due to repeated expansion / contraction of internal air. It is to be.

Another object of the present invention is to provide a belt wrapping device which can prevent the belt from meandering by using the above-described heating roller of the present invention.

Still another object of the present invention is to provide a sheet heating element which can prevent abnormal temperature rise and improve safety and is suitable for a heating roller and other uses.

[0010]

SUMMARY OF THE INVENTION The present invention provides a hollow metal heating roller body, a planar heating element arranged in contact with the inner peripheral surface of the heating roller body, and both ends of the heating roller body in the axial direction. A power supply means, one end of each power supply means being electrically connected to the planar heating element and the other end being exposed from the end of the heating roller body. And a power cut-off provided in the internal space of the heating roller main body, interposed in the middle of the path of the power of the sheet heating element supplied from the power supply means, and shutting off when the sheet heating element has an abnormally high temperature. And a heating roller.

According to the present invention, a sheet heating element is provided on the inner peripheral surface of, for example, a straight cylindrical heating roller body made of a metal having good thermal conductivity, such as aluminum, and both ends of the heating roller body are respectively provided. Electric power is supplied to the sheet heating element from the provided power supply means, the sheet heating element generates heat by Joule heat, and the outer peripheral surface of the heating roller body has a temperature suitable for fixing in, for example, an electrophotographic image forming apparatus. Heated. The temperature of the outer peripheral surface of the heating roller body is, for example, 1
It may be 60 to 200 ° C.

When the temperature of the sheet heating element becomes abnormally high, the power cutoff means cuts off the power supplied to the sheet heating element. This prevents fires from occurring and ensures safety. The abnormally high temperature at which the power cutoff unit cuts off the power may be, for example, 200 to 250 ° C.

[0013] The power cut-off means is provided in the internal space of the heating roller main body, so that the power cut-off operation can be accurately performed in response to the temperature of the sheet heating element in the internal space of the heating roller main body, and the operation is reliable. is there. Further, since the power cut-off means is provided in the internal space of the heating roller main body as described above, there is no possibility that the power cut-off means will be adversely affected by the external atmosphere and malfunction, thereby also ensuring safety. Further, by providing the power cut-off means in the internal space of the heating roller main body, the handling of the heating roller becomes easy, and when assembling the heating roller in an application such as a fixing device, the assembling work becomes easy and productivity is improved. Will be. In this way, the abnormally high temperature of the sheet heating element is suppressed, and there is no possibility that the sheet heating element emits smoke or carbonize, thereby preventing the occurrence of fire.

Further, the present invention is characterized in that the power cutoff means is provided on the planar heating element near an axial end of the heating roller main body.

According to the present invention, the power cut-off means is provided on the sheet heating element, whereby the power can be cut off in response to the abnormally high temperature, and the operation can be further reliably performed. Become. Such a power cutoff means may be realized by, for example, a thermal fuse that blows at the abnormally high temperature. This power cut-off means is provided near the axial end of the heating roller body, and thus can be interposed in the middle of the power path between the sheet heating element and the power supply means. It is possible to provide the power cutoff means commonly to the resistors, and the power path can be simplified.

Further, the present invention is characterized in that the power cutoff means is interposed and connected between the sheet heating element and the power supply means.

According to the present invention, the power cutoff means may have, for example, the shape of a tubular electronic component, may have, for example, a cylindrical or disk shape, and may have a planar heating element. By being connected between the power supply means and the power supply means, the assembling work is easy. Further, in this configuration, the sheet heating element and the power cut-off means can be manufactured separately, which facilitates manufacture and acquisition.

Further, according to the present invention, the heating roller body has a right cylindrical shape, and journals are respectively provided at both ends of the heating roller body. Each journal has a flange fixed to both ends of the heating roller body. A flange provided on the flange, having the same axis as the heating roller body, extending outward in the axial direction of the heating roller body, and having a journal shaft supported by a bearing; It is characterized in that an air hole for communicating the internal space of the roller body with the outside is provided.

According to the present invention, a disc-shaped or flat annular flange provided at both ends of the straight cylindrical heating roller body is fixed. A flange may be press-fitted into the end of the heating roller body to fix the heating roller body and the flange. The surface of the peripheral portion of the flange may be brought into contact with the end surface perpendicular to the axis of the end portion of the heating roller body to apply pressure perpendicularly to the boundary surface and adhere, and may be pressed and fixed.

The flange is provided with a journal shaft, and the journal shaft is supported by a bearing. The journal consisting of the flange and the journal shaft may be formed integrally by cutting or forging metal, but in another embodiment of the invention, the flange and the journal shaft are They may be manufactured separately, and the flange and the journal shaft may be fixed by press-fitting or press-fitting and other welding.

The expansion of air in the internal space of the heating roller body /
In order to ensure that the end of the heating roller body does not separate from the flange due to shrinkage and that the end of the heating roller body is securely fixed to the flange, at least one of the journals has an air hole. Provided. Therefore, even if the pressure of the air in the internal space of the heating roller body expands during the operation of the heating roller, the air in the internal space is discharged to the outside, and when the heating roller returns to normal temperature, the external air is released from the heating roller body. Into the interior space of. Therefore, no force acts in the direction in which the end of the heating roller body and the flange are separated from each other, and the fixed state between the end of the heating roller body and the flange is stably maintained.

In order to make the pressure in the internal space of the heating roller main body substantially equal to the atmospheric pressure, the air hole may have a relatively small inner diameter, for example, 1 to 3 mmφ.
Therefore, there is no problem that heat dissipation from the internal space of the heating roller body becomes significant. Therefore, the heating by the planar heating element of the heating roller body can be efficiently performed, and the heat retaining property can be maintained.

Further, the present invention is characterized in that the air holes are formed only in the flange.

According to the present invention, the air hole formed in the journal is formed only in the flange as shown in FIG. Therefore, it is possible to prevent foreign matter, for example, conductive toner in an electrophotographic image forming apparatus and a metal piece from a metal gear, etc. from entering the internal space of the heating roller main body from the outside through the air holes. Is done. If such conductive toner and metal pieces enter the internal space of the heating roller body, a short circuit in the electric circuit occurs, which causes a spark, which is dangerous, but the present invention avoids such a problem. can do.

In another embodiment of the invention, the air holes are:
It may be provided not only on the flange but also on the journal shaft, or an air hole may be formed only in the journal shaft so as to communicate with the internal space of the heating roller body. The air holes may be formed in only one journal, or may be formed in two journals respectively.

The present invention also provides (a) a hollow metallic heating roller main body, (b) a planar heating element arranged in contact with the inner peripheral surface of the heating roller main body, and (c) a heating roller main body. Journals provided at both ends, each journal has a flange fixed to both ends of the heating roller body, provided on the flange, has the same axis as the axis of the heating roller body, the journal of the heating roller body Extending axially outward,
A journal having a journal shaft supported by a bearing; and (d) a pair of power supply means provided at both ends in the axial direction of the heating roller main body, wherein each power supply means is made of a metal penetrating the journal. A combination of a bolt and a metal nut screwed to the bolt, wherein one end of the combination is electrically connected to the planar heating element, and the other end of the combination is an end of the heating roller body. A combination of a bolt and a nut exposed from a portion, and a current collector provided to be rotatable with respect to the combination around the axis of the heating roller body and electrically connected to the combination. A power supply means having a member, wherein the direction of the screw of the bolt of each combination and the nut screwed to the bolt is the direction of tightening by rotation about the axis of the heating roller body. A heating roller which comprises.

According to the present invention, electric power for the sheet heating element is supplied to the sheet heating element from the current collecting member of the power supply means via a combination of bolts and nuts. The current collecting member is provided at the fixed position, or provided at the fixed position with a relatively small displacement allowed. The direction of the screw between the bolt and the nut is determined in the direction in which the bolt and the nut are tightened when the heating roller body rotates during operation. Therefore, there is no possibility that the screwed state of the bolt and the nut is loosened by the rotation of the heating roller body. Therefore, power supply to the planar heating element is performed stably and reliably.

Power supply means are provided at both ends in the axial direction of the heating roller body as described above, and the directions of the screws in the combination of the bolt and the nut of each power supply means are opposite to each other.

Further, according to the present invention, the power supply means is electrically connected to the assembly at a position outside the journal in the axial direction of the heating roller body, and is formed in a ring shape around the axis of the heating roller body. It has a ring, and the current collecting member resiliently contacts the current collecting ring and slides.

According to the present invention, the current collecting member resiliently abuts on the current collecting ring and slides, thereby making an electrical connection. Power can be supplied to the sheet heating element via the combination of the above. The sliding position between the current collecting ring and the current collecting member may be a position shifted in the radial direction from the axis of the heating roller body, or may be a position very close to the axis. The distance between the current collecting member and the current collecting member can be made as small as possible, and wear of both the current collecting ring and the current collecting member can be prevented as much as possible.

Further, according to the present invention, the power supply means is held at the free end of the journal shaft so as to be rotatable with respect to the free end around the axis of the heating roller body, and covers the current collecting ring. A current collecting member attached to the holding member, and a flexible line for supplying electric power is connected to the current collecting member.

According to the present invention, the current collector ring is covered with a holding member made of an electrically insulating material, for example, synthetic resin or ceramic, that is, the holding member is axially outward from the free end of the journal shaft. The holding member is rotatable about the free end of the journal shaft and the axis of the heating roller body, and slides in contact with the current collecting ring. Current collecting member is mounted. A flexible line is connected to the current collecting member. For example, the flexible line may be a power line including a plurality of thin wires, or may be a power line including a plurality of thin wires. One end of the flexible line is connected and fixed to the current collecting member, and the other end of the flexible line is provided at a fixed position. This flexible line thus prevents the current collecting member, and thus the holding member, from rotating with the journal shaft, and thus the heating roller body, and displaces the end of the heating roller body, and thus the free end of the journal shaft. Is acceptable. Therefore, in a configuration in which a belt meandering prevention device described later is provided in association with the journal shaft portion, when the journal shaft portion is displaced to prevent belt meandering, a flexible line, a collection It is ensured that electric power is continuously supplied to the sheet heating element via the electric member, the current collecting ring, and the combination of the bolt and the nut.

Further, the present invention is characterized in that the combination of the power supply means has a current collecting portion on the axis of the heating roller body, and the current collecting member elastically contacts the current collecting portion. And

According to the present invention, when the end of the heating roller main body is not displaced, or even if it is displaced, the amount of displacement is small, as shown in FIG. 23, provided on the axis of the heating roller main body. A current collecting member provided at a fixed position can be constantly and elastically brought into contact with a provided current collecting portion, for example, a bolt head of a bolt in the above-described combination of a bolt and a nut. In this way, it is assured that electric power is always supplied from the current collector to the planar heating element from the combination of the bolt and the nut via the current collector.

According to another aspect of the present invention, there is provided a belt winding including an endless belt, a plurality of belt conveying rollers around which the belt is wound and rotatably supporting the belt, and a pressure roller for sandwiching and conveying the sheet between the belts. In the hanging device, one of the belt transport rollers is a heating roller, and the heating roller includes: (a) a hollow metal heating roller main body;
(B) a planar heating element arranged in contact with the inner peripheral surface of the heating roller main body, and (c) journals provided at both ends of the heating roller main body, wherein each journal is provided at both ends of the heating roller main body. A journal provided with the flange fixed to the portion, having the same axis as the axis of the heating roller body, extending outward in the axial direction of the heating roller body, and having a journal shaft supported by a bearing. ,
(D) A pair of power supply means provided at both ends in the axial direction of the heating roller main body, wherein each power supply means is a combination of a metal bolt inserted through the journal and a metal nut screwed to the bolt. One end of the combined body is electrically connected to the planar heating element, and the other end of the combined body is a combined body of a bolt and a nut exposed from an end of the heating roller body; A current collecting member that is provided rotatably with respect to the combination body around the axis of the roller body and that supplies electric power in a state of being electrically connected to the combination body; The direction of the screw with the nut screwed into the bolt includes power supply means that is a direction tightened by rotation about the axis of the heating roller body, and at least one of the journal shafts includes
Belt meandering prevention means for preventing belt meandering is provided, and the belt meandering prevention means is a (e) meandering detection member, which is rotatably supported by the journal shaft portion and coaxial with the detection member main body. A meandering detection member supported by the shaft end and having a belt contact portion facing the belt and in contact with the belt; and (f) the journal shaft supporting the meandering detection member is predetermined to be orthogonal to the axis of the heating roller. A roller supporting means for supporting the displaceable member in the displacement direction;
The shaft end supporting the meandering detection member of the heating roller is displaced in the predetermined displacement direction when the belt is in contact with the detection member main body and the belt contacts the belt contact portion to apply a torque to the detection member main body. And a roller shaft end displacing means.

According to the present invention, for example, the belt wrapping device of the present invention can be embodied as a belt fixing device in an electrophotographic image forming apparatus, and power is supplied from a power supply unit to a sheet heating element. Can be. In order to prevent meandering of the belt wound around the heating roller main body, at least one of the journal shafts is provided with belt meandering prevention means, and the belt meandering prevention means is provided with the belt meandering prevention means. Although the shaft portion is displaced in a direction perpendicular to the axis of the heating roller main body, such displacement is allowed, and power can always be supplied from the power supply means to the sheet heating element. In this belt meandering preventing means, a meandering detection member is supported on the journal shaft so as to be rotatable with respect to the shaft end. When the belt is displaced by meandering and comes into contact with the belt contact portion of the meandering detecting member, the meandering detecting member is rotated by frictional contact with the belt, and the rotation of the meandering detecting member is linearly moved by the action of the roller shaft end displacement means. Is converted to As a result, at least one journal shaft portion of the heating roller supporting the meandering detection member is displaced in a predetermined displacement direction.
As a result, when the at least one journal shaft portion of the heating roller is displaced, a meandering displacement is generated in the belt in the opposite direction, and the initial meandering is eliminated. Thus, the displacement of the at least one journal shaft portion of the heating roller corresponding to the initial meandering displacement amount is automatically given, and the meandering is eliminated and the belt runs stably.

The meandering detecting member, that is, the meandering detecting means, may be supported on both shaft ends of the one belt conveying roller, or may be supported on only one of the shaft ends.

Further, according to the present invention, the power supply means, which is provided near the one journal shaft provided with the belt meandering prevention means, is electrically connected to the assembly at a position axially outward of the heating roller body relative to the journal. And a current collecting ring formed annularly around the axis of the heating roller main body. The current collecting member resiliently abuts and slides on the current collecting ring, and the free end of the journal shaft portion The part has a holding member that is rotatably held around the axis of the heating roller main body and the free end and that covers the current collecting ring and is made of an electrically insulating material. A flexible line for supplying power is connected to the current collecting member, and the combination of the power supply means disposed near the other journal shaft portion where the belt meandering prevention means is not provided includes a heating roller. On the axis of the body It has a conductive portion, to the current collecting part, a belt winding device, characterized in that the current collecting member is contacted to resiliently.

According to the present invention, in the journal shaft portion provided with the belt meandering preventing means, the power supply means has the structure of the above-mentioned claims 8 and 9, whereby the journal shaft portion provided with the belt meandering preventing means is provided. Even if displacement due to meandering of the belt occurs, power can always be reliably supplied to the sheet heating element via the power supply means.

In a configuration in which the belt meandering preventing means is not provided on the other journal shaft portion, the displacement amount of the other journal shaft portion is relatively small or hardly displaced. By the power supply means having the configuration, it is possible to supply electric power while suppressing wear on the current collecting member.

According to the present invention, there is also provided a film-like synthetic resin base material having electrical insulation and flexibility, and an electric power formed on one surface of the base material and having a predetermined direction between both ends. An electric resistor that is supplied and generates heat, terminals that are formed on the one surface of the base material, and are respectively provided outside the one direction from both ends of the electric resistor, and at least one end of the electric resistor And a power cut-off means interposed between the terminal and the terminal and cut off when an abnormally high temperature is generated by an electric resistor.

According to the present invention, an electric resistor and a terminal are formed on one surface of a film-shaped synthetic resin base material such as a polyimide resin, and a power cutoff means is interposed between the electric resistor and the terminal. Therefore, when an abnormally high temperature occurs, the power cut-off means cuts off the power to the electric resistor, thereby preventing the base material from smoking and carbonizing, preventing the occurrence of fire, and ensuring safety. Nature is secured. The abnormally high temperature at which the power cutoff means cuts off the power is, for example, 300 to 50
0 ° C., preferably for example 300-33
It may be 0 ° C. Since the power cut-off means is incorporated in the sheet heating element, there is no need to provide such a power cut-off means externally in addition to the sheet heating element, so that the handling becomes easy and electronic equipment using the sheet heating element, etc. In addition to simplifying the manufacture of the device, there is no possibility that the operation of the power cut-off means may become unstable due to the external environment, and the power can be cut off in response to a desired abnormally high temperature, thereby improving safety. Can be improved.

Further, according to the present invention, the power cutoff means may include a flat temperature fuse that blows at an abnormally high temperature, and a conductive fuse that bonds the fuse to the at least one end of the electric resistor and the terminal. And an adhesive.

According to the present invention, the power cutoff means provided on the base is a thermal fuse connected between the end of the electric resistor and the terminal via a conductive adhesive. The fuse has a flat shape, so that the overall shape of the planar heating element can be flattened. The thermal fuse has a characteristic of fusing when the temperature reaches the above-mentioned abnormally high temperature, and may be plastic including tin, for example. The thermal fuse does not blow when a relatively large current is applied to raise the temperature of the electric resistor to a desired temperature in a short time. Therefore, as described above, a large current can be applied to the electric resistor to raise the temperature to a desired temperature in a short time, whereby it is necessary to always supply power to the electric resistor to maintain a desired temperature state. Gone
This is preferable from the viewpoint of reducing power consumption.

The conductive adhesive is a mixture of a powder of, for example, silver or tin and a synthetic resin, and has a temperature lower than the abnormally high temperature at which the thermal fuse is blown, and higher than the temperature during normal operation. May have the property of melting in the range described above, or may have the property of not melting at a temperature exceeding the abnormal temperature. In bonding the end of the electric resistor and the terminal with a conductive adhesive,
By pre-processing the surfaces to be bonded to rough surfaces, the bonding strength of the bonding material can be improved, whereby the thermal fuse electrically connects the ends and the terminals of the electric resistor. Can be reliably conducted.

According to the present invention, only the heating roller of the present invention is used for heat fixing between a pressure roller and a belt without using a belt in an electrophotographic image forming apparatus. Rather, the invention can be practiced in connection with a wide variety of other technical fields, such as heating rollers for general industry and heating rollers for heating belts in the field of belt transport.

[0047]

FIG. 1 is a horizontal sectional view of a part of a belt fixing device 1 according to an embodiment of the present invention, and FIG.
3 is a horizontal sectional view of the remaining part of the belt fixing device 1, and FIG.
5 is a simplified longitudinal sectional view of the belt fixing device 1. FIG. FIG. 1 shows FIG.
FIG. 2 is a cross-sectional view as seen from the section line II-II in FIG. 12, and FIG. 2 is a cross-sectional view as seen from the section plane line II-II in FIG. FIG. 3 is a sectional view taken along a line III-I in FIG.
FIG. 4 is a sectional view taken along line II of FIG.
It is sectional drawing seen from V-IV. Referring to these drawings, belt fixing device 1 is used by being built in an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile machine. In the fixing device main body 2, between the fixing roller 3 and the hollow heating roller 5, an endless belt 6 is provided.
Is wound. A pressure roller 7 is arranged below the fixing roller 3. The recording paper 8 having the toner image on the upper surface is shown in FIG.
3 and from right to left in FIG. 5, as indicated by arrow 9. When the recording paper 8 is over a relatively long distance, for example, about 160 to 200
The toner image is heated and melted by the pressure roller 7 while being pressed against the belt 6 heated to a temperature of 0 ° C., and then cooled and fixed. The fixing roller 3, the heating roller 5, and the pressure roller 7 have a substantially horizontal axis. The recording paper 8 is guided by upper and lower guide members 10 and 11 on the entrance side and guided by guide members 12 and 13 on the exit side.

The heating roller 5 is basically a hollow straight cylindrical heating roller body 151 made of a metal having good thermal conductivity such as aluminum, and the heating roller body 151.
1, and a pair of power supply means 153 (FIG. 1) provided at both ends in the axial direction of the heating roller body 151 to heat the heating roller body 151 by Joule heat. And FIG. 2) and 154 (see FIG. 3 and FIG. 4),
55 (see FIGS. 8 and 9 described later). The fixing roller 3 has a layer having at least a surface having elasticity. The pressure roller 7 has a configuration in which a layer made of a synthetic resin material such as Teflon (trade name) is formed on a metal surface such as aluminum to prevent foreign substances such as toner and oil from adhering. Is also good.

Of the two side plates 14 and 15 of the fixing device main body 2, an insertion hole 66 is formed in the side plate 14 as clearly shown in FIG. The belt 6 can be detached to the right in FIGS. 1 and 2 to be detached or inserted into the fixing device main body 2 by using the insertion hole 66.
The shaft ends 17, 18 of the fixing roller 3 are supported by bearings 19, 20. A drive gear 22 is detachably connected to the shaft end portion 18 by a retaining ring 21, whereby the fixing roller 3 is driven to rotate, and the belt 6 is run by this power. Thus, the heating roller 5 and the pressure roller 7 are driven to rotate. The journals 23, 24 of the heating roller 5 are supported by bearings 25, 26.

FIG. 6 is a perspective view showing the heating roller 5 with a part cut away. FIG. 7 is a cross-sectional view of a part of the heating roller 5 shown in FIG. On the inner peripheral surface of the heating roller body 151, an inner coating layer 156 made of an electrically insulating synthetic resin material, for example, a polyimide resin, is provided.
Are arranged in a cylindrical shape continuously in the circumferential direction except for both ends.
The planar heating element 1 is provided radially inward of the inner coating layer 156.
52 are arranged.

FIG. 8 is a perspective view of the sheet heating element 152.
The sheet heating element 152 is formed by attaching an electric resistor 158 to one surface in the radial direction of a base 157 made of a synthetic resin material having electrical insulation, for example, a polyimide resin. The electric resistor 158 is made of a material such as stainless steel. The electric resistor 158 extends in the axial direction of the heating roller main body 151 (the left-right direction in FIG. 8) and is bent in a zigzag manner in the circumferential direction. The plurality of electric resistors 158 are formed in the circumferential direction (for example, in this embodiment). In the embodiment, 4) is arranged in parallel. Both ends of these electric resistors 158 are connected to a common connection portion 159 near both ends in the axial direction of the heating roller body 151. These common connection portions 159 generate Joule heat when electric power is supplied to the base material 157 in one predetermined direction, that is, between both end portions 160 in the axial direction of the heating roller main body 151. The terminal 161 is in one direction, that is, the heating roller body 15
One is formed on the one surface of the base material 157 outwardly in the axial direction (leftward and rightward in FIG. 8). The thickness of the inner coating layer 156 and the substrate 157 is, for example, 25 to 30 μm.
m, it has flexibility and is in the form of a film. The thickness of the electric resistor 158 is 25 to 30 μm, and may be made of a metal material such as stainless steel or another conductive material. A single power cutoff unit 155 is electrically connected between the common connection unit 159 and the terminal 161.

FIG. 9 is an enlarged sectional view of the power cut-off means 155 viewed from IX-IX in FIG. This power cutoff means 1
55 includes a thermal fuse 162 that blows at an unusually high temperature above 160-200 ° C. suitable for heat fusing, for example 300-500 ° C., preferably 300-330 ° C. This thermal fuse 162 is flat and ribbon-shaped. Both ends of the thermal fuse 162 are connected to the common connection portion 15.
9 and the terminal 161 are connected and fixed by conductive adhesives 163 and 164. Conductive adhesive 163, 16
4 may be a graphite paste containing a conductive powder such as silver or tin, for example. The terminal 161 extends over the entire width of the base 157 in the width direction (the vertical direction in FIG. 8).

FIG. 10 is a sectional view perpendicular to the axis of a part of the heating roller body 151. The sheet heating element 152 is formed of the base material 15.
7 is bent so as to be continuous in the circumferential direction of the heating roller body 151, and is stored in the inner peripheral surface of the inner coating layer 156 in a state of being expanded by the elastic force of the sheet heating element 152. Is done. The terminal 161 is connected to the substrate 1 as described above.
57, the sheet heating element 15
2 is rounded as shown in FIG.
Numeral 61 is endlessly connected in the circumferential direction. Heating roller body 151
Is rotated in the rotation direction 165, and the radially inner end 152 a of the sheet heating element 152 becomes the radially outer end 152.
The terminal 161 is arranged on the upstream side in the rotation direction 165 with respect to b to prevent the terminal 161 from being caught when a brush or the like contacts.

FIG. 11 is a simplified cross-sectional view showing a method of manufacturing the sheet heating element 152. The base material 157 is a roll 166
Supplied from A belt 167 made of a metal material such as stainless steel is supplied from a roll 168. The base member 157 and the metal band 167 are conveyed while being sandwiched between a pair of press-contacted heating rollers 169 and 170, whereby the metal band 167 is attached to one surface of the base member 157 and fixed. The metal strip 167 on the base material 157 thus obtained is immersed in an etching solution to be selectively removed, and the electric resistor 158, the common connection part 159, and the terminal 1
61 are formed to remain on one surface of the base material 157.
As shown in FIG. 9 described above, the thermal fuse 162 is fixed using the conductive adhesives 163 and 164 over the common connection portion 159 and the terminal 161 thus obtained. Thus, the sheet heating element 152 is completed.

FIG. 11B is a cross-sectional view showing another method of manufacturing the sheet heating element 152. A metal band 167 of stainless steel or the like is supplied from a roll 168, and a synthetic resin material 173 of a liquid base material 157 is supplied from a supply hole 172 of a hopper 171 on the way, and the metal band 167 is supplied.
7 is coated in the form of a film. Thus, the base material 15
7 and the metal band 167 are integrally attached. The subsequent manufacturing steps are the same as the manufacturing steps described with reference to FIG.

A resilient member 174 is accommodated inside the planar heating element 152 in the radial direction. This resilient member 174 may be made of, for example, a spongy foam synthetic resin material.
Alternatively, the elastic member 174 may be made of rubber such as silicone rubber, or may be a metal coil coated with an electrically insulating synthetic resin material. The sheet heating element 152 is elastically pressed against the inner peripheral surface of the heating roller main body 151 via the inner coating layer 156 and is brought into close contact therewith.

FIG. 12 is a right side view of the fixing device main body 2, FIG. 13 is an exploded perspective view of the vicinity of the side plate 14, and FIG. 14 is a perspective view showing the configuration of the journal 23 and the vicinity thereof. In FIGS. 12 and 13, the configuration of the journal 25 and its vicinity is omitted to clarify the configuration near the side plate 15. The journal 23 is made of a metal material such as aluminum, for example, and is fixed to one end of the heating roller body 151. This journal 23 has a flange 1
75 and a journal shaft 176. Flange 1
75 is pressed into the end of the heating roller body 151 and fixed. The journal shaft portion 176 is provided on the flange 175, has the same axis as the axis of the heating roller body 151, extends outward in the axial direction of the heating roller body 151 (to the right in FIG. It is rotatably supported. The journal shaft 176 has a right cylindrical shape.

The heating roller body 15 is located closer than the flange 175.
An insulating member 177 made of an electrically insulating synthetic resin material, for example, a PPS (polyphenylene sulfide) resin, and a current-carrying member 178 are arranged inward in the axial direction. The current-carrying member 178 is made of a conductive metal material such as stainless steel, and has contact pieces 180 that protrude radially outward from the disk-shaped base 179 at equal intervals in the circumferential direction. In the embodiment of the present invention, for example, three or more contact pieces 180 (four in this embodiment) are provided. The contact piece 180 contacts the terminal 161 of the sheet heating element 152 and is electrically connected inside the heating roller body 151.
The contact piece 180 has a spring force radially outward of the heating roller body 151. Thereby, the electrical connection between the contact piece 180 and the terminal 161 is ensured.

FIG. 15 is a perspective view showing the structure of the belt meandering preventing means 63 provided in connection with the journal shaft portion 176.

The base 179 of the conducting member 178 and the insulating member 1
In 77, insertion holes 186 and 187 through which bolts 185 (see FIG. 16) described later are inserted are formed. Bolt 185
As shown in FIG. 16, a bolt shaft 188 and a bolt head 18 formed at an end of the bolt shaft 188 are formed.
9 is provided. An external screw formed at the end of the bolt shaft 188 opposite to the bolt head 189 is detachably screwed to the nut 181. The bolt 185 and the nut 181 form a combination 190, and the bolt 185 and the nut 181 are made of metal and conductive.

FIG. 16 shows a power supply means 15 provided in connection with the journal 23 at the end of the heating roller body 151.
3 is an exploded perspective view showing a part of the configuration of FIG. The sleeve 192 made of an electrically insulating synthetic resin material such as PPS has a straight cylindrical tubular portion 193 and an outward flange 194 formed at an end of the tubular portion 193. The cylindrical portion 193 is inserted through the journal shaft portion 176. The flange 194 is in contact with the free end surface of the journal shaft 176.

The disk-shaped current collector 196 of the current collector ring 195 contacts the flange 194 of the sleeve 192. An insertion hole 197 through which the bolt shaft 188 of the bolt 185 is inserted is formed in the current collector 196. Current collector ring 195
Has a cylindrical portion 198 connected to the current collecting plate 196 and extending in a direction opposite to the sleeve 192. The current collecting ring 195
For example, it is made of a metal material such as stainless steel. The bolt 185 and the nut 181 of the combined body 190 are tightened, so that the current collecting ring 195, the bolt 185, the nut 181, the base 179 of the current-carrying member 178, the contact piece 18
0, it is electrically connected to one terminal 161 of the sheet heating element 152.

The bolt head 189 is a countersunk screw as clearly shown in FIGS.
8 is formed in a truncated cone shape having a larger diameter as it goes outward in the axial direction (to the right in FIGS. 1 and 2). Collector ring 19
The insertion hole 197 formed in the current collecting plate 196 of No. 5 is formed so that the inner peripheral surface becomes smaller in diameter as it approaches the bolt shaft portion 188 corresponding to the outer peripheral surface of the bolt head 189.
Thus, the end surface 199 of the bolt head 189 on the side opposite to the bolt shaft portion 188 is substantially flush with the surface of the current collector 196 on the side opposite to the sleeve 192. The bolt head 189 has
An engagement groove for the driver bit may be formed. The current collecting ring 195 is formed in an annular shape around the axis of the heating roller body 151.

A current collecting member 200 is provided to be electrically connected to the current collecting ring 195 to supply power. The current collecting member 200 is made of, for example, a metal material having excellent elasticity, for example, a material such as phosphor bronze. Current collecting member 2
00 is a base 201, a pair of support pieces 202 and a terminal piece 2
03 and a mounting piece 204, and a contact 205 made of a material such as silver is fixed to the support piece 202 so as to project toward the current collecting plate 196 of the current collecting ring 195.

FIG. 17 is a front view of the power supply means 153 viewed from the right side of FIG. 2, and FIG. 18 is a developed view of the current collecting member 200. Referring to FIG. 16 as well, current collecting member 200 is formed by bending a plate-like body. By the function of the support piece 202, the contact point 205 can resiliently contact the current collector plate 196 and slide.

The current collecting member 200 is held by the holding member 206. The holding member 206 is made of, for example, an electrically insulating material such as PPS, and is held at the free end of the journal shaft 176 so as to be rotatable with respect to the free end around the axis of the heating roller body 151. The holding member 206 covers the current collecting ring 195. The holding member 206 is connected to the end plate 20.
7 and a holding cylinder 208 extending from the end plate 207 toward the current collecting ring 195. The vicinity of the opening end of the holding cylinder 208 is thick. A plurality (for example, three) of screw holes 209 are formed in the thick portion of the holding cylinder 208 at intervals in the circumferential direction. A retaining protrusion 210 made of a bolt is detachably screwed and fixed to the screw hole 209. The retaining protrusion 210 penetrates the holding cylinder 208 and protrudes inward in the radial direction thereof, and the current collecting plate 1 of the current collecting ring 195.
It is located closer to the sleeve 192 than 96. Current collecting part 20
The contact 205 is formed by the spring force of the
By resiliently abutting the 95 current collector 196,
The retaining projection 210 is provided on the current collecting plate 1 of the current collecting ring 195.
96 contacts the surface opposite to the contact 205. This prevents the retaining projection 210 from detaching axially outward (to the right in FIG. 2) from the current collecting ring 195, and thus from the journal shaft 176.

Mounting holes 211 and 212 are formed in the end plate 207 of the holding member 206. The mounting piece 204 of the current collecting member 200 is inserted into one of the mounting holes 212, and the end of the mounting piece 204 is bent outward in the radial direction of the end plate 207 as is apparent in FIG. Terminal piece 203 is another
The two mounting holes 211 are inserted and bent outwardly in the radial direction as clearly shown in FIG. Current collecting member 2
The base 201 of the sheet holder 00 is supported in contact with the end plate 207 of the holding member 206. The terminal strip 203 has a flexible line 2
13 is connected to one end. The other end of the line 213 is connected to the mounting member 21
4 and the line 213 is fixed while being electrically insulated from the auxiliary plate 72. This line 213 is
When the heating roller 5 rotates, the holding member 206
When pulled by the frictional force between the contact member 205 and the contact point 205, the holding member 206 serves to prevent the rotation of the holding member 206 and allows the journal 23 to be displaced by the function of the belt meandering preventing means 63.

The power supply means 154 of the other journal 24 is particularly clearly shown in FIG. 4, which is symmetrical to the aforementioned power supply means 153, perpendicular to the axis of the heating roller body 151. It is configured symmetrically about a plane. The aforementioned power supply means 15 of the power supply means 154
The portions corresponding to 3 are indicated by the same numerals with a suffix a.

FIG. 19 is a left side view of the fixing device main body 2, and FIG. 20 is an exploded perspective view of the vicinity of the side plate 15. The shaft end 31 (see FIG. 13) and the shaft end 32 of the pressure roller 7 are supported by bearings 33 and 34.

The supporting member 45 includes a belt tension applying spring 5.
One end 56 of FIG. 5 shown in FIG. 2 is detachably locked. The other end 57 of the spring 55 is detachably connected to the side plate 15. Thus, the spring 55 includes the support member 45,
Therefore, a spring force is applied to the heating roller 5 so as to move away from the fixing roller 3 in the radial direction.

The side plate 15 has an opening 6 for easy maintenance of the heating roller 5 near the journal 24.
4 and a heating roller 5 connected to the opening 64.
, An elongated opening 65 extending in a direction away from the fixing roller 3 is formed. The spring 55 is disposed in the opening 65.

The support member 45 has a locking hole 114 for locking the end 56 of the spring 55. Further, a removable screw hole 115 for the bolt 59 is formed in the support member 45.

Referring to FIG. 3 again, bearing 20 supporting shaft end 18 of fixing roller 3 includes outer ring 101 and inner ring 102.
And rolling elements 116 interposed between them. The shaft end 18 is inserted through the inner ring 102, and is detachably detachable via the drive gear 22 by the retaining ring 21 as described above.
02 is prevented from moving outward in the axial direction (leftward in FIG. 3). The outer ring 101 has a retaining ring 103 outside the side plate 15.
Resiliently and removably fit. As a result, the outer ring 1
01 is prevented from moving in the axial direction (to the right in FIG. 3).

Referring to FIG. 5 again, a pressure lever 35 and a pressure spring 36 are provided near the side plate 15 in order to apply a spring force to the pressure roller 7 in a direction toward the fixing roller 3. One end of the pressure lever 35 is provided to be angularly displaceable by a pin 37 having an axis parallel to the axis of the pressure roller 7. The other end 38 of the pressure lever 35 has a spring 3
One end 39 of 6 is detachably locked. The other end 40 of the spring 36 is detachably locked to a locking piece 41 protruding from the side plate 15. The pressure lever 35 abuts on the peripheral surface of the shaft end 32 on the opposite side of the bearing 34 (the lower side in FIG. 5) from the fixing roller 3, and the pressure lever 35
5 applies a counterclockwise spring force about the axis of the pin 37 in FIG. Thus, the pressing roller 7 is provided with a spring force toward the fixing roller 3, and the pressing roller 7 is pressed against the belt 6. The bearing 33 of the pressure roller 7 is also provided with a configuration similar to the above-described pressure lever 35 and spring 36 symmetrically with respect to the shaft end 32 in relation to the side plate 14.

In order that the bearing 34 can be displaced in the vertical direction which is the radial direction of the fixing roller 3, the side plate 15
The oval guide elongated hole 43 extending vertically is formed in the
Similarly, the vertical displacement of the bearing 33 is allowed,
A guide slot 42 is formed in the side plate 15 as shown in FIG. These guide slots 42 and 43 have bearings 33 and 34 respectively.
Is fitted and guided. Shaft end 3 of pressure roller 7
The reference numerals 1 and 32 are smaller than the outer diameter of the pressure roller body with which the belt 6 is pressed and smaller than the outer diameters of the bearings 33 and 34, and can be removed from the insertion / removal hole 66 and can be inserted. . Further, the shaft ends 31, 32 are provided with bearings 33, 3
4 can be removed.

A support member 45 is disposed outside the side plate 15 of the fixing device main body 2 (to the left in FIGS. 3 and 4 and above the plane of FIG. 19). The support member 45 is provided in the radial direction of the fixing roller 3 (the vertical direction in FIGS. 3 and 4 and the horizontal direction in FIG. 19).
Are guided by the guide pieces 46 and 47 so as to be movable.
The guide pieces 46, 47 are detachably fixed to the side plate 15 by mounting bolts 118, 119, and have guide portions 48, 49 for forming guide grooves for guiding the upper and lower sides of the support member 45 with the side plate 15. .

The journal 24 is attached to the inner ring 52 of the bearing 26.
Is inserted. A rolling element 44 is interposed between the outer ring 51 and the inner ring 52. On the outer side of the support member 45, that is, on the side opposite to the side plate 15 (left side in FIGS. 3 and 4),
The journal 24 of the heating roller 5 is also provided with an annular groove in which a retaining ring 54 is resiliently and removably fitted, whereby the journal 24 is axially inward (FIG. 3).
(Rightward in FIG. 4). Further, the outer ring 51 of the bearing 26 and the support member 45 allow the outer ring 51 and thus the bearing 2
6 is prevented from displacing inward (rightward in FIGS. 3 and 4) with respect to the support member 45 along the axis of the heating roller 5.

Referring again to FIGS. 12 and 13, the belt 6 is attached to the side plate 14 as described above.
An insertion / removal hole 66 is formed for insertion into or removal from the fixing device main body 2. Further, an opening 67 connected to the insertion / removal hole 66 is formed in the side plate 14. The opening 67 extends in a direction away from the fixing roller 3 with respect to the heating roller 5.
The guide elongated hole 42 is connected to and connected to the insertion / removal hole 66 via the connection hole 68. Width W1 of connection hole 68 (see FIG. 13)
Is equal to or greater than the outer diameter D1 of the shaft end 31 of the pressure roller 7 (W1 ≧
D1). Therefore, when the bearing 33 is not fitted in the guide slot 42 and the shaft end 31 is not inserted through the bearing 33, the shaft end 31 moves up and down in the connection hole 68 in FIG. can do. The outer diameter of the pressure roller 7 is set to be equal to or less than the vertical distance between the insertion and removal holes 66 in FIG. Bearings 3 are provided on the shaft ends 31 and 32 of the pressure roller 7.
The configuration in which the journals 3 and 34 are attached is described below, in which the journal 23 of the heating roller 5 is supported by the bearing 25 and attached to the support member 73, and the configuration in which another journal 24 is attached to the support member 45 by the bearing 26. The same is true. By detachably removing the retaining rings associated with the bearings 33 and 34, the bearings 33 and 34 can be removed from the shaft ends 31 and 32 of the pressure roller 7.
An E-ring may be used instead of each of the retaining rings described above.

Bearings 19, 20; 25, 26 and 33,
Numeral 34 denotes a rolling bearing, whose rolling elements 44, 76,
Each of 116 and 117 may be a ball, and a sliding bearing may be used in place of the rolling bearing, and can receive a thrust force and a radial force.

Outside the side plate 14 (right side in FIGS. 1 and 2,
13, a lid 71 that closes the insertion hole 66 and the opening 67 and partially closes the connection hole 68 is provided. The lid 71 includes an auxiliary plate 72 and a support member 73. The auxiliary plate 72 has a bolt insertion hole 75 through which a plurality of (for example, four) bolts 74 are inserted. The bolt 74 is detachably screwed into a screw hole 76 formed in the side plate 14. In this way, the auxiliary plate 72 is accurately positioned so as to be detachable from the side plate 14 and fixed.

The auxiliary plate 72 includes the shaft end 1 of the fixing roller 3.
The bearing 19 that supports 7 is detachably fitted and mounted. The bearing 25 is detachably fitted to the support member 73. An oval guide elongated hole 77 (see FIG. 12) for guiding the bearing 25 in the radial direction of the fixing roller 3 is formed in the auxiliary plate 72 so as to correspond to the bearing 25.

Referring to FIG. 2, bearing 25 has outer ring 78, inner ring 79, and rolling elements 76 interposed therebetween. Outside the support member 73 (to the right in FIGS. 1 and 2),
The outer ring 78 is formed with an outward flange 80, which prevents the outer ring 78, and thus the bearing 25, from being displaced axially inward of the heating roller 5 (to the left in FIGS. 1 and 2). The journal 23 of the heating roller 5 includes the inner ring 7
The retaining ring 81 is detachably fitted outside the support member 73 beyond the position 9. Thus, displacement of the shaft end 23 inward in the axial direction (leftward in FIG. 2) is prevented.

The support member 73 is formed with an oval guide elongated hole 50 which is elongated in the vertical direction perpendicular to the radial direction of the fixing roller 3. The guide slot 50 has a heating roller 5
The outer ring 78 of the bearing 25 that supports the journal 23 is disposed.

Referring to FIG. 19 and FIG.
The outer ring 51 has a through hole 142 formed in the support member 45.
Are loosely inserted to play. That is, there is a slight gap between the outer diameter of the outer ring 51 and the inner diameter of the play hole 142. Accordingly, the bearing 25 supporting the journal 23 of the heating roller 5 is displaced along the guide long hole 50 formed in the support member 73 by the operation of the belt meandering preventing means 63, and the axis of the heating roller 5 is allowed to tilt. In addition, the function of the belt tension applying springs 55 and 82 allows the axis of the heating roller 5 to be inclined.

As for the inner ring 52 of the bearing 26 and the journal 24 of the heating roller 5, as shown in FIG. 4, the journal 24 loosens the inner ring 52 so that mutual displacement is allowed along the axis of the heating roller 5. Through. Therefore, the heating roller 5 is allowed to expand in the axial direction. Due to the thermal expansion of the heating roller 5 during the fixing operation,
As shown in FIG. 4, a gap d2 between the bearing 26 and the retaining ring 54 can occur. This gap d2 is
During the fixing operation, the distance may be, for example, 1.5 to 2 mm.

On the other hand, the journal 2 of the heating roller 5
2, as clearly shown in FIG. 2, the mutual displacement of the heating roller 5 with respect to the side plate 14 in the axial direction (left-right direction in FIG. 2) is zero or almost zero, and the journal 23 of the heating roller 5 And the side plate 14 are prevented from being displaced in the axial direction. Therefore, in the journal 23, the retaining ring 81 and the retaining ring 138 described later prevent the displacement of the heating roller 5 with respect to the outer ring 78 of the bearing 25 along the axial direction.
In addition, the guide members 95 and 96 of the guide pieces 93 and 94 provided on the auxiliary plate 72 support the support member 73 via the auxiliary plate 72.
The displacement of the side plate 14 and the heating roller 5 along the axial direction is prevented. Further, the outer ring 78 of the bearing 25 and the support member 73
Means that the outer ring 78,
Therefore, the bearing 25 is prevented from being displaced inward (leftward in FIG. 2) with respect to the support member 73 along the axis of the heating roller 5. In order to prevent the journal 23 from being displaced axially outward (to the left in FIG. 2) of the heating roller 5 with respect to the support member 73, the displacement control member 139 includes an inner race 79.
A meandering detection spring 127 of the belt meandering preventing means 63 is substantially fitted between the support member 73 and the displacement limiting member 139 in contact with an axially inner end face (left side in FIG. 2) of the outer ring 78 and the outer ring 78. Is interposed.

The support member 73 includes a belt tension applying spring 8.
The second end 83 is detachably locked. The other end 84 of the spring 82 is locked by a spring locking piece 85. Spring 82
Is located at the opening 67. A screw hole 87 is formed in a rising portion 86 of the spring engagement piece 85.

An upright portion 88 is formed below the spring locking piece 85 of the auxiliary plate 72 in FIG. The upright portion 88 includes a spring force adjusting bolt 8.
A bolt insertion hole 90 through which the bolt 9 is inserted is formed. The shaft portion of the bolt insertion hole 90 where the male screw is cut is screwed into the screw hole 87. The bolt head of the bolt 89 comes into contact with the upright portion 88. By angularly displacing the bolt 89 about its axis in this way, the spring retaining piece 85 is displaced and adjusted in the left-right direction in FIG. 12, and the tension of the belt 6 is adjusted.

A long hole 91 for adjustment is formed in the spring retaining piece 85 along the direction in which the spring 82 extends. Adjustment bolt 9
2 is inserted into the long hole for adjustment 91 and screwed into a screw hole formed in the side plate 14. With the bolts 92 loosened in this way, the tension of the belt 6 is set by the bolts 89, and then the bolts 92 are tightened so that the spring retaining pieces 8
5 is fixed to the auxiliary plate 72. The auxiliary plate 72 includes the side plate 14
The openings 9 correspond to the openings 67 formed in the openings 9.
8 are formed. These openings 67 and 98 have springs 8
2 are arranged.

The insertion / removal hole 66 has a shape larger than the cross-sectional outer diameter of the belt 6 stretched around the fixing roller 3 and the heating roller 5. Thus, it is possible to easily pull out the belt 6 to the outside of the side plate 14 and insert it into the fixing device main body 2 while maintaining the substantially stretched shape.

Referring to FIG. 1 again, bearing 19 supporting shaft end 17 of fixing roller 3 includes outer ring 104 and inner ring 105.
And rolling elements 117 interposed therebetween. A retaining ring 106 is resiliently and removably fitted to the outer ring 104 outside the auxiliary plate 72. The inner ring 10 is attached to the shaft end 17.
The retaining ring 107 is removably and resiliently fitted outside the outer ring 5. Thus, displacement of the outer ring 104, and thus the bearing 19, inward in the axial direction (leftward in FIG. 1) is prevented,
The inner ring 105, and therefore the bearing 19, is axially outward (FIG. 1).
To the right) is prevented. The fixing roller 3 is shown in FIG.
1 and the retaining rings 106 and 107 shown in FIG. 1 prevent axial displacement of the fixing device main body 2 including the side plates 14 and 15.

When removing the belt 6 wound around the fixing roller 3 and the heating roller 5, the ends 56, 57; 83, 8 of the belt tension applying springs 55, 82 are removed.
4 is removed, and the tension of the belt 6 is released. Further, one of the ends 39 and 40 of the spring 36 related to the bearing 33 of the pressure roller 7 is removed to release the pressing force, and another bearing 34 of the pressure roller 7 (see FIG. 20 described above). In the same manner, the pressing force is released.

Next, retaining rings 81 provided in connection with the bearing 25 of the heating roller 5 and the bearing 19 of the fixing roller 3,
Remove 107. Thereafter, the bolts 74 fixing the auxiliary plate 72 are removed, and the lid 71 is removed from the side plate 14 in this manner. Thereby, the insertion / removal hole 66 faces outward. In this state, the belt 6 can be pulled out of the side plate 14 from the insertion hole 66.

The belt 6 can be pulled out of the side plate 14 from the insertion hole 66 as described above, and the heating roller 5 and the fixing roller 3 can be individually taken out as follows. Furthermore, the belt 6 and the heating roller 5
The fixing roller 3 and the fixing roller 3 can be simultaneously drawn out of the side plate 14 through the insertion / removal hole 66.

Before removing the heating roller 5 from the insertion hole 66, the retaining ring 54 is first removed. Thus, the heating roller can be pulled out of the side plate 14. Thereby, it is not necessary to disassemble the belt meandering prevention device 63, and the workability is good.

Further, the fixing roller 3 is fixed to the fixing device main body 2.
In order to remove the retaining ring, the retaining ring 21 attached to the shaft end 18 in FIG. 1 is removed. Thereby, the fixing roller 3 can be taken out from the side plate 14 through the insertion / removal hole 66.

It is also possible to take out the pressure roller 7 from the fixing device main body 2 through the insertion / removal hole 66. For this purpose, first, the shaft ends 31 (FIG. 13) and 32 of the pressure roller 7 are
The bearings 33 and 34 are removed from (FIG. 20). Bearings 33, 3
4 is removed from the guide slots 42 and 43 of the side plates 14 and 15. Therefore, the shaft end 31 of FIG. 13 is provided to the insertion / removal hole 66 via the connection hole 68. Thus, the pressure roller 7 is inserted into and removed from the insertion hole 6.
6 can be taken out of the side plate 14.

The heating roller 5 is moved from the fixing device main body 2 to the side plate 1.
5 can also be taken out. For this purpose, FIG.
The heating roller 5 can be taken out of the side plate 15 from the opening 64 shown in FIG. 20 together with the support member 45 shown in FIG.

Prior to the removal of the heating roller 5, the guide pieces 46, 47 are attached from the side plate 15 to the mounting bolts 1.
18, 119 can be detachably detached, so that the support member 45 can be detached from the side plate 15. Alternatively, the journal 24 of the heating roller 5 is removed together with the bearing 26 from the support member 45, and the heating roller 5 is displaced inward of the fixing device main body 2 in this state. Thereby, the supporting member 4
20 can be removed along the guide pieces 46 and 47, for example, to the left in FIG.

FIG. 1, FIG. 2, FIG. 12, FIG. 13 and FIG.
The belt meandering preventing means 63 will be described with reference to FIG. The meandering detection member 120 is disposed on the journal 23 of the heating roller 5, and the journal 23 rotatably inserts the detection member main body 145 into each other.
20 is supported by a journal 23. Journal 23
Is formed to be smaller than the outer diameter of the belt guide portion 121 that guides the belt 6 of the heating roller 5.
The meandering detection member 120 has a belt contact member 123 having a contact surface 122. The meandering detection member 120 includes the above-described detection member main body 145 and the belt contact member 123. The central hole 146 of the belt contact member 123 has a hollow straight cylindrical shaft portion 147 of the detection member main body 145.
Is inserted, fitted, or press-fitted and fixed. An end surface 148 of the detection member main body 145 facing the belt contact member 123 is perpendicular to the rotation axis of the heating roller 5,
The belt contact member 123 comes into surface contact with the end surface opposite to the contact surface 122 and comes into contact therewith. The detection member main body 145 may be made of a synthetic resin material excellent in slidability, such as a PPS (polyphenylene sulfide) resin, which slides well with a low coefficient of friction with the journal 24 of the heating roller 5, and a belt contact member. 123 may be made of a polyamide-imide resin, which is a synthetic resin material having better wear resistance than the material of the detection member main body 145. These detection member main bodies 1
45 and the belt contact member 123 may be integrally manufactured by synthetic resin molding, or may be manufactured separately, and both may be firmly fixed by fitting or press fitting as described above. Alternatively, both 145 and 123 may be fixed using an adhesive.

The contact surface 122 forms an angle θ1 with the axis of the heating roller 5 in a plane including the axis of rotation of the heating roller 5 (see FIG. 2).
Are chosen almost vertically. The contact surface 122 of the belt contact member 123 of the meandering detection member 120 forms an angle θ1 with the axis of the heating roller 5 in a plane including the axis (see FIG. 2).
May be selected to be substantially vertical, i.e., 90 degrees or less than 90 degrees and approximately 90 degrees, e.g., in the range of 70-90 degrees, or may be selected in the range of 85-90 degrees; It may be 89 degrees. Thus, the angle θ1
It has been confirmed by experiments of the present inventor that by setting the angle substantially perpendicularly, the meandering amount of the belt 6 can be reduced and the life of the belt 6 can be prolonged. End 124 on the small diameter side of contact surface 122 of belt contact member 123
Is equal to the outer diameter of the belt guide portion 121 of the heating roller 5.

The journal 23 has an outer diameter smaller than the belt guide 121 around which the belt 6 of the heating roller 5 is wound. The journal 23 has a meandering detecting member 120.
Is inserted coaxially. An outer end of the journal 23 in the axial direction (rightward in FIG. 1) is supported by a support member 45 via a bearing 25.

The guide slot 50 described above is formed in the support member 73 constituting the roller support means 140. The guide slot 50 allows the bearing 25 to be displaced in the direction perpendicular to the plane of FIG. 1, that is, the vertical displacement in FIGS. 12 and 13. The extending direction of the guide slot 50 is the vertical direction of the support member 73 in FIG.
2 and a direction orthogonal to the left-right direction in FIG.

Belt contact member 12 of meandering detection member 120
3 (the right side in FIGS. 1 and 2) in the axial direction,
A straight cylindrical cable guide 125 is integrally formed. The cable guide portion 125 is formed with a flange 126 that protrudes radially outwardly toward the outside of the cable guide portion 125 in the axial direction (to the right in FIGS. 1 and 2). Flange 1
The outer peripheral surface of 26 is formed in the shape of a truncated cone whose outer diameter increases as it goes outward from the cable guide portion 125 in the axial direction.

Further, the meandering detection spring 127 substantially surrounds the lower half of the bearing 26 in a substantially U-shape. The two upper ends 128 and 129 of the meandering detection spring 127 are supported by the support member 73.
Are locked by the pins 130 and 131. In this way, the bearing 25 in the guide slot 50, that is, the journal 23 of the heating roller 5 is given a spring force in one direction upward in the plane of FIG. 1 and upward in FIGS.

When the outer ring 78 of the bearing 25 is in contact with the upper end 143 of the elongated hole 50 (see FIG. 2) due to the spring force of the spring 127, the belt 6 is moved in the width direction of the belt 6, and therefore, is heated. The vehicle travels displaced toward the meandering detection member 120 in the axial direction of the roller 5.

The cable 132 is flexible and does not expand or contract, and its one end 133 is connected to the meandering detecting member 120 by a pin 134 as clearly shown in FIG. It is fixed to the strip guide 125. The other end 135 of the cable 132 is detachably connected to and fixed to the support member 73 by a pin 136. The rope 132 is attached to the rope guide 125 by a meandering detection spring 127.
Is wound on the opposite side in the circumferential direction partially, for example, about half a turn. Thus, the cable 132 is connected to the cable detecting member 12.
0 is the same rotation direction as the heating roller 5 137
(See FIG. 13), when the cable 132 is angularly displaced,
The journal 23 of the heating roller 5 is wrapped around the cable guide portion 125, whereby the journal 23 of the heating roller 5 is opposed to the spring force in one direction above FIG. 12 and FIG. It is displaced in the other direction below FIG.

When the belt 6 meanders and rides on and comes into contact with the contact surface 122 of the belt contact member 123 of the meandering detection member 120, a large rotational torque acts on the meandering detection member 120 according to the amount of meandering in the belt width direction. I do. As a result, the cable 132 is wound around the cable guide 125. As a result, the journal 23 is displaced downward in FIGS. Therefore, a meandering component toward the side plate 14 is generated on the belt 6, and the journal 23 is displaced downward along the guide slot 50 until the initial meandering component toward the side plate 15 is canceled. .

As the belt 6 meanders and rides on the belt contact member 123 to make contact therewith, a frictional force acts between the belt 6 and the contact surface 122, and thus the meandering detection member 120 is actuated as described above. It is rotated with respect to the journal 23. This rotation causes the cable 132 to wind around the cable guide 125 as described above. The winding force of the cable 132 and the spring force of the meandering detection spring 127 are balanced, and the amount of downward displacement of the journal 26 in FIGS. 12 and 13 is regulated. Thus, the end of the belt 6 is fixed at a certain position. The position of the part on the contact surface 122 will be maintained.

When the force for displacing the journal 23 is applied to the lower side of FIGS. 12 and 13 as described above, the supporting member 45 on the other journal 24 side of the heating roller 5 is clearly shown in FIG. The outer ring 51 of the bearing 26 is loosely inserted into the play hole 142 with a gap, or in another embodiment of the present invention, the looseness of the bearing 25 causes the bearing 25 to rattle. The axis of the heating roller 5 can be inclined with respect to one virtual plane including the axis. This allows the journal 23 to be displaced downwardly in FIGS. 12 and 13 to prevent belt meandering as described above.

Referring to FIG. 1 and FIG.
A retaining ring 138 is removably attached to the journal 23 outside the journal 23 in the axial direction.
By the action of the retaining ring 138, the meandering detection member 120
Is prevented from displacing the journal 23 outward in the axial direction. The end 124 of the meandering detection member 120 is
Abuts on the end face of the belt guide portion 121 to limit displacement in the axial direction inward (to the right in FIGS. 1 and 2).

Further, a disc-shaped displacement limiting member 139 is interposed between the retaining ring 138 and the bearing 25. The displacement limiting member 139 has an outer diameter larger than the outer ring 78 of the bearing 25, and has an outer diameter slightly larger than the curved portion of the meandering detection spring 127 wound in a U-shape. This prevents the meandering detection spring 127 from being displaced to the right in FIGS. 1 and 2 from the outer peripheral surface of the outer ring 78 and coming off. Further, this displacement limiting member 139 is
Since the outer diameter is larger than 26, the rope 132 is prevented from coming into contact with the bearing 26 and the meandering detection spring 127, and there is no possibility of being entangled. Large displacement to the right (in FIGS. 1 and 2) is prevented. In this way, the meandering preventing operation of the belt 6 is reliably achieved.

[0113] The cable guide portion 125 formed integrally with the meandering detection member 120, the meandering detection spring 127, and the cable 1
32 and constitute the roller shaft end displacement means.

In another embodiment of the present invention, the cord 132
, A meandering detection spring 127 is used.
May be omitted. Instead of using the cable 132, a coaxial pinion is fixed to the meandering detection member 120, and the support member 7
At 3, a rack meshing with the pinion may be fixed so that the journal 23 may be displaced. Alternatively, one end of a rigid rod may be pin-connected to the side wall of the meandering detection member 120, and the other end of the rod may be used. May be pin-connected to the support member 73 so that the journal 23 is displaced when the belt 6 meanders.

The belt 6 has a thickness of, for example, 40 to 50 μm.
Is about 120 μm thick on the outer surface of Ni which is a metal material having a relatively small coefficient of thermal expansion to prevent toner offset.
Has a configuration in which a coating layer made of a synthetic resin such as a silicon resin is formed. The meandering detection member 120 may be made of metal, or may be made of a synthetic resin material having excellent wear resistance, for example, a polyamideimide-based synthetic resin.

FIG. 1 to FIG. 20 described above and FIG.
In the embodiment shown in FIG.
Is provided on the inner side of the side plate 14 (the left side in FIGS. 1 and 2) and closer to the side plate 14. Therefore, when the belt 6 is replaced, the belt meandering detection device 63 provided near the lid 71 can be easily inspected, and the meandering detection member 120 can be removed from the retaining rings 81 and 138. It is easily replaceable.

FIG. 21 shows power supply means 153, 1 provided at both ends of the heating roller body 151 in the axial direction.
It is a figure which shows the combination bodies 190 and 190a provided in 54 in a simplified manner. Nut 1 of combination body 190, 190a
The directions 216, 217 of the screws 84, 184a and the bolts 185, 185a are tightened by the rotation in the rotation direction 215 around the axis of the heating roller main body 151, and the rotation direction 215 of the bolts 185, 185a.
Is the opposite direction. That is, bolts 185, 18
5a, when the assembly worker rotates using a driver,
These fastening directions 216, 217 are opposite to each other. As a result, the heating roller body 151 is
5, when performing the heat fixing operation, the bolt 185,
There is no possibility that the power supply means 185a will loosen from the nuts 184 and 184a and come off.
4 ensures that power is supplied to the planar heating element 152.

FIG. 22 is a simplified electric circuit diagram relating to the sheet heating element 152. A temperature detecting element 218 is provided in contact with an end of the heating roller body 151 in the axial direction, and detects the temperature of the surface of the heating roller body 151.
Flexible line 2 electrically connected to planar heating element 152
The power supplies 13 and 213a are further connected to a power supply circuit 219 to be supplied with power. The power supplied from the power supply circuit 219 to the sheet heating element 152 is controlled by the temperature control circuit 220. The temperature control circuit 220 includes the temperature detecting element 21
8 and the output of the temperature setting circuit 221 so that the temperature detected by the temperature detecting element 218 matches the temperature set in the temperature setting circuit 221.
The power supply circuit 219 controls power supplied to the sheet heating element 152. As a result, the temperature of the surface of the heating roller body 151 is kept constant at a temperature suitable for heat fixing. Further, when the temperature of the sheet heating element 152 becomes abnormally high due to a failure of the temperature detecting element 218, the temperature control circuit 220, the power supply circuit 219, or the like, the temperature fuse 162
The power is cut off by the action of, and safety is ensured.

FIGS. 23 to 29 show another embodiment of the present invention.
This will be described with reference to FIG. This embodiment is based on FIGS.
Similar to the embodiment of FIG. 22, corresponding parts are denoted by the same reference numerals. It should be noted that in this embodiment, the configuration of the power supply means 154 related to the journal 24 is different from the above-described embodiment.

FIG. 23 is a sectional view showing the configuration of the journal 24 and the power supply means 154 provided in connection with the journal 24, and FIG. 24 is a left side view of the present belt fixing device. The configurations shown in FIGS. 23 and 24 correspond to the configurations shown in FIGS. 4 and 20 described above. Referring to these drawings, heating roller body 151
The flange 175a of the journal 24 is press-fitted and fixed to an end of the journal 24. In the journal 24, there is a sleeve 1
The cylindrical portion 193a of the 92a is inserted, and the flange 194a contacts the end surface of the journal shaft portion 176a. Combination 1
A bolt 185a and a nut 181a that constitute 90a are provided. Bolt head 189a of this bolt 185a
Has a hexagonal bolt engaging portion that can be engaged with a spanner or the like, and a top surface of the bolt head 189a is a current collector 225.
The current collector 225 is perpendicular to the axis of the heating roller body 151.

The current collecting member 226 has a resilient support piece 227, and a contact 228 is fixed to an end of the support piece 227. The contact 228 is connected to the current collector 225 by the support piece 2.
The spring is pressed by the spring force of 27, and is electrically contacted on the axis of the heating roller body 151. The base end of the support piece 227 is fixed to the support member 45 via a bolt 230 screwed to a cylindrical fixing member 229 made of an electrically insulating synthetic resin. Power is supplied to the support piece 227 via a flexible power line, and thereby the displacement of the support member 45 with respect to the side plate 15 is allowed.

In this embodiment, the power supply means 15
The connection means 231 is provided in connection with the nut 181a of the combination 190a in FIG. This connection means 231
Functions to electrically connect the nut 181a and the terminal 161 of the sheet heating element 152.

FIG. 25 is a circumferential development of the sheet heating element 152 used in the embodiment shown in FIGS. This planar heating element 152 is the same as that shown in FIG.
It should be noted that in this embodiment, the end 160 of the electric resistor 158 is connected to the terminal 161 extending in the width direction of the base 157 (vertical direction in FIG. 25). Connected to. In the embodiment of the present invention, the above-described thermal fuse 162 is not provided in the sheet heating element 152. Other configurations are the same as those of the above-described embodiment.

FIG. 26 is a cross-sectional view of the connecting means 231 as viewed from the section line XXVI-XXVI in FIG.
FIG. 27 is an exploded perspective view of the connection means 231.
The connecting means 231 includes an insulating member 232 made of an electrically insulating synthetic resin material that comes into contact with the flange 175a, an assembly member 233 made of an electrically insulating synthetic resin material, a first connecting member 234, and a second connecting member 235. . The first and second connection members 234 and 235 are made of metal such as stainless steel. The insulating member 232 has an insertion hole 236 through which the bolt 185a is inserted, and an air hole 237.
Is formed. The air holes 237 communicate with air holes 238 formed in the flange 175a of the journal 24. An air hole 239 is also formed in the assembly member 233. In this way, the internal space of the heating roller body 151 can communicate with the outside through these air holes 239, 237, 238. Therefore, the internal space of the heating roller body 151 can be maintained at substantially the atmospheric pressure regardless of heating / cooling of the planar heating element 152. Therefore, the end of the heating roller body 151 and the flange 1 of the journal 24
75a is maintained in a fixed state.

FIG. 28 shows the first and second connecting members 23.
FIG. 4 is an exploded perspective view showing 4,235 and an assembly member 233. The first connection member 234 includes an annular base 240,
The terminal 16 of the sheet heating element 151 is connected to the base 240.
1, a mounting piece 243 extending from the central hole 242 of the base 240 toward the assembly member 233, and a side opposite to the assembly member 233 from the central hole 242, that is, the heating roller body 151. And a terminal portion 244 extending inward in the axial direction. A plurality (for example, three) of the contact pieces 241 are provided at equal intervals in the circumferential direction, and a plurality (for example, three) of the mounting pieces 243 are formed at the same position in the circumferential direction as the contact piece 241. The mounting piece 243 is inserted through a mounting hole 245 formed in the assembly member 233, and is bent and fixed radially outward.

The second connection member 235 has a base 246, a plurality of (for example, three) attachment pieces 247 provided at intervals in the circumferential direction, and a terminal 248. Mounting piece 247
Is inserted through a mounting hole 249 formed in the assembly member 233, is bent inward in the radial direction, and is fixed. Base 24
6 also has a central hole 250 formed therein.
0, the screw hole of the nut 181a is exposed and the bolt 185
a bolt shaft portion 188a can protrude.

The lead wires 252 of the tubular thermal fuse element 251 are connected to the terminals 244 and 248, respectively. The thermal fuse element 251 has a configuration similar to that of the thermal fuse 162 described in relation to FIGS. 8 and 9 and constitutes a power cutoff unit.

FIG. 29 is an exploded perspective view of the current collecting member 226 and its vicinity. An insertion hole 252 is formed in the fixing member 229. A mounting bolt 253 is inserted through the insertion hole 252 and is screwed to the support member 45. The support piece 227
It is fixed to the fixing member 229 by the bolt 230. Therefore, the support piece 227 and the contact point 228 are connected to the support member 45.
Are fixed in an electrically insulated state. Bolt 25
3 is screwed into the screw hole 255 of the support member 45. Therefore, the electric power from the supporting piece 227 of the current collecting member 226 is supplied from the contact 228 to the bolt 185 of the combination 190a.
a from the current collector 225 via the nut 181a, from the base 246 of the second connecting member 235, from the terminal 248 via the thermal fuse element 251 and further to the first connecting member 234.
25 through the terminal portion 244, the base 240, and the contact piece 241.
Supplied to

In the above embodiment, since the contact 228 contacts the current collector 225 of the bolt 185a on the axis of the heating roller body 151, the contact 228 and the sliding part 225 are provided.
Wear can be minimized. Air hole 2
Since 38 is formed on the flange 175 a of the journal 24, it is possible to prevent foreign matter such as conductive toner and metal pieces such as bearings from entering from the air holes 238. Since the thermal fuse element 251 is not built in the sheet heating element 152 and is separate, it is easy to select the temperature characteristic at which the thermal fuse element 252 melts. Other configurations and operations are the same as those of the above-described embodiment.

FIG. 30 is a partial sectional view of still another embodiment of the present invention. This embodiment corresponds to FIG.
Similar to the embodiment shown in FIGS. 3 to 29, corresponding parts are denoted by the same reference numerals. In this embodiment, an air hole 256 is formed in the journal shaft portion 176a of the journal 24 so that the internal space of the heating roller main body 151 can communicate with the outside.
Through the air hole 256 formed in the insulating member 232
Communicating with the air hole 237. The air hole 237 communicates with the air hole 239 of the assembly member 233 via a gap 257 between the insulating member 232 and the assembly member 233.

The other structure of the embodiment of the present invention shown in FIG. 30 is the same as that of the above-described embodiments shown in FIGS.

FIG. 31 is a partial cross-sectional view of another embodiment of the present invention. The surface of the peripheral portion of the flange 258 of the journal 23 is pressed and welded to the heating roller body 151 at the end face of the heating roller body 151 as indicated by reference numeral 259, and is fixed. Other configurations are the same as those of the above-described embodiment. A configuration in which the flanges 175 and 175a are pressed into the end of the heating roller main body 151 as in the respective embodiments shown in FIGS.
In the configuration in which the flanges 258 are pressed against each other as shown in FIG.
The production can be performed without a high temperature acting to the extent that 2 is damaged.

The experimental results of the present inventor will be described. Figure 1
FIG. 32 shows the experimental result of the diffusing property of the fixing temperature in the belt fixing device in the embodiment of FIG. The features of the present invention are designated by reference numeral 261. Heating roller body 1
After the temperature of the outer peripheral surface of the journal shaft portion 176 of the 51 journal 23 is stabilized at 200 ° C., the heating roller body 151 is not supplied with power to the sheet heating element 152 and the rotation of the heating roller body 151 is stopped. 5 shows the results of measuring the drop of the temperature of the outer peripheral surface over time with time. The internal space of the heating roller body 151 has a closed configuration. When the temperature of the outer peripheral surface of the heating roller body 151 is 200 ° C., the temperature of the journal shaft portion 176 of the journal 23 is 66.5 ° C. from FIG. 32. It turns out that the sex is slight. This was also true for journal 24.

On the other hand, in a conventional belt fixing device as shown in FIG. 34, an elongated rod-shaped halogen lamp 267 is inserted into the heating roller main body 266 as described above in connection with the conventional technology. In the configuration in which the end 268 of the halogen lamp 267 is coaxially supported on the heating roller main body 266 by the support piece 269, the inner peripheral surface of the journal shaft portion 270 of the heating roller main body 266 and the outer peripheral surface of the halogen lamp 267 are provided. , An annular space 271 is formed, whereby the internal space of the heating roller main body 266 communicates with the outside. The temperature of the outer peripheral surface of the journal shaft portion 270 in this configuration is indicated by reference numeral 262 in FIG. Temperature 200 on the outer peripheral surface of the heating roller body 266
The temperature of the journal 270 at 9 ° C. is 95.5 ° C. as shown in FIG. 32. Therefore, in the configuration using the conventional halogen lamp 267 shown in FIG. Is remarkable.

FIG. 33 is a graph showing experimental results of heat retention in the embodiment of the present invention shown in FIGS.
The characteristics in the embodiment of the present invention are indicated by reference numeral 263, and the experimental results of the configuration having the halogen lamp 267 shown in FIG. 34 are indicated by reference numeral 264. After keeping the outer peripheral surface of the heating roller body 151 at 200 ° C., the supply of power to the sheet heating element 152 is cut off, and the rotation of the heating roller body 151 is stopped.
The temperature of the outer peripheral surface of Sample No. 1 was measured with respect to the elapse of time. In the characteristic 263 of the present invention, it was confirmed that the temperature drop was more gradual and the heat retention was excellent as compared with the characteristic 264 of the configuration using the halogen lamp 267 shown in FIG.

The characteristics of the embodiment of the present invention shown in FIGS. 23 to 29 and the embodiment of the present invention shown in FIG. 30 also correspond to the characteristics 261 of FIG. 32 and FIG.
Is almost the same as the characteristic 263 of FIG.
It was confirmed that the heat retention was excellent.

[0137]

According to the first aspect of the present invention, when the temperature of the planar heating element becomes abnormally high, the power cut-off means is
Since the power supplied to the sheet heating element is cut off, the abnormally high temperature of the sheet heating element is suppressed, the sheet heating element does not emit smoke or carbonize, and the occurrence of a fire is prevented. In this way, safety is ensured. In particular, in the present invention, since the power cut-off means is provided in the internal space of the heating roller main body, there is no possibility of malfunction due to an adverse effect of the external atmosphere. Therefore, the shut-off operation can be performed accurately in response to the temperature of the planar heating element in the internal space of the heating roller body, and the operation is reliable. In addition, since the power cutoff means is provided in the internal space of the heating roller main body, handling of the heating roller becomes easy, and when assembling the heating roller in an application such as a fixing device, the assembling work becomes easy.
Productivity can be improved.

According to the second aspect of the present invention, since the power cut-off means is provided on the planar heating element, the power can be cut off in response to the abnormally high temperature without fail. Is more certain. Further, since the power cut-off means is provided near the axial end of the heating roller main body, it can be interposed in the middle of the power path between the sheet heating element and the power supply means. It is possible to provide a common power cutoff means for the heating resistors, and the power path can be simplified.

According to the third aspect of the present invention, the power cutoff means may have, for example, the shape of a tubular electronic component, and may have, for example, a cylindrical or disk shape. The assembling operation is facilitated by being connected between the planar heating element and the power supply means. Further, in this configuration, the sheet heating element and the power cut-off means can be manufactured separately, which facilitates manufacture and acquisition.

According to the fourth aspect of the present invention, since the air hole is provided in at least one of the journals, even if the pressure of the air in the internal space of the heating roller body expands during the operation of the heating roller, the air hole is provided. When the air in the internal space is exhausted to the outside and the heating roller returns to room temperature, the external air can enter the internal space of the heating roller body.
Therefore, no force acts in the direction in which the end of the heating roller body and the flange are separated from each other, and the fixed state between the end of the heating roller body and the flange is stably maintained. Further, in order to make the pressure in the internal space of the heating roller main body substantially equal to the atmospheric pressure, the air hole only needs to have a relatively small inner diameter. In addition, the heating by the planar heating element of the heating roller body can be efficiently performed, and the heat retaining property can be maintained.

According to the fifth aspect of the present invention, foreign matters, such as conductive toner and metal fragments from a metal gear in an electrophotographic image forming apparatus, are introduced from the outside into the internal space of the heating roller body. It is possible to reliably avoid the problem that the electric circuit enters into the internal space of the heating roller main body through the hole to cause a short circuit of the electric circuit and generate a spark.

According to the sixth aspect of the present invention, the direction of the screw of the bolt and the nut, which is a combination of the power supply means, is such that the bolt and the nut are not connected when the heating roller body rotates during operation. Since the tightening direction is determined, the screwed state of the bolt and the nut is not loosened by the rotation of the heating roller main body, and the power supply to the planar heating element can be stably and reliably performed.

According to the seventh aspect of the present invention, the current collecting member resiliently abuts on the current collecting ring and slides, thereby making an electrical connection. Through,
Electric power can be supplied to the sheet heating element via the combination of the bolt and the nut.

According to the eighth aspect of the present invention, the flexible line prevents the current collecting member, and thus the holding member, from rotating together with the journal shaft, and thus the heating roller body, and the end of the heating roller body. Part, and therefore the free end of the journal shaft, is allowed to be displaced,
For example, even if the journal shaft is displaced to prevent the belt from meandering, the displacement can be allowed, and the planar heating element includes a flexible line, a current collecting member, a current collecting ring,
Power can be continuously supplied to the sheet heating element via the combination of the bolt and the nut.

According to the ninth aspect of the present invention, even if the end portion of the heating roller main body is slightly displaced, the current collecting portion provided on the axis of the heating roller main body has a current collecting portion provided at a fixed position. The power member can always be elastically contacted, and thus the power can be constantly supplied from the current collector to the planar heating element from the combination of the bolt and the nut via the power collector.

According to the tenth aspect of the present invention, the belt is meanderingly displaced and comes into contact with the belt contact portion of the meandering detecting member.
As a result, when the meandering detection member rotates due to frictional contact with the belt, the action of the roller shaft end displacement means causes
The rotational movement of the meandering detecting member is converted to a linear movement, thereby causing a meandering displacement in the opposite direction on the belt, and the initial meandering is eliminated. In this way, the displacement of the at least one journal shaft portion of the heating roller corresponding to the initial meandering displacement amount is automatically given, and the meandering is eliminated and the belt can run stably.

In particular, according to the present invention, the journal shaft provided with the belt meandering preventing means is allowed to be displaced in the direction perpendicular to the axis of the heating roller main body, so that the electric power supplying means always supplies electric power to the sheet heating element. Thus, accurate formation of a toner image on recording paper can be achieved.

According to the eleventh aspect of the present invention, in the journal shaft portion provided with the belt meandering preventing means, the power supply means has the above-described structure of the eighth and ninth aspects, whereby the belt meandering preventing means is provided. Even if displacement of the journal shaft portion provided with is caused due to meandering of the belt, power can always be reliably supplied to the sheet heating element via the power supply means.

In a configuration in which the belt meandering preventing means is not provided on the other journal shaft portion, the displacement amount of the other journal shaft portion is relatively small or hardly displaced. By the power supply means having the configuration, it is possible to supply electric power while suppressing wear on the current collecting member.

According to the twelfth aspect of the present invention, since the power cut-off means is incorporated in the sheet heating element, there is no need to provide such a power cut-off means externally in addition to the sheet heating element. This facilitates the manufacture of devices such as electronic devices using the planar heating element, and does not cause the operation of the power cutoff means to become unstable due to the external environment. The power can be cut off in response, and the safety can be improved.

According to the thirteenth aspect of the present invention, the thermal fuse does not blow when a relatively large current is applied to the electric resistor to raise the temperature to a desired temperature in a short time. Therefore, as described above, a large current can be applied to the electric resistor to raise the temperature to a desired temperature in a short time, whereby it is necessary to always supply power to the electric resistor to maintain a desired temperature state. Power consumption can be reduced.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of a part of a belt fixing device 1 according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the configuration shown in FIG.

FIG. 3 is a horizontal sectional view of the remaining part of the belt fixing device 1.

FIG. 4 is a longitudinal sectional view of the configuration shown in FIG. 3;

FIG. 5 is a simplified longitudinal sectional view of the belt fixing device 1.

FIG. 6 is a perspective view showing the heating roller 5 with a part cut away.

7 is a sectional view of a part of the heating roller 5 shown in FIG.

FIG. 8 is a perspective view of a planar heating element 152.

FIG. 9 is a power cutoff unit 155 viewed from IX-IX in FIG. 8;
It is an expanded sectional view of.

FIG. 10 is a cross-sectional view perpendicular to an axis of a part of the heating roller body 151.

FIG. 11 is a simplified cross-sectional view illustrating a method of manufacturing the sheet heating element 152. FIG. 11 (2) shows the surface heating element 15
FIG. 6 is a cross-sectional view showing another method for manufacturing the second embodiment.

FIG. 12 is a right side view of the fixing device main body 2.

FIG. 13 is an exploded perspective view of the vicinity of the side plate 14;

FIG. 14 is a perspective view showing a configuration of a journal 23 and its vicinity.

FIG. 15 is a perspective view illustrating a configuration of a belt meandering preventing unit 63 provided in association with the journal shaft portion 176.

16 is a journal 2 at the end of the heating roller body 151. FIG.
FIG. 3 is an exploded perspective view illustrating a configuration of a part of a power supply unit 153 provided in association with the power supply unit 3.

17 is a front view of the power supply unit 153 as viewed from the right side in FIG.

18 is a development view of the current collecting member 200. FIG.

FIG. 19 is a left side view of the fixing device main body 2.

FIG. 20 is an exploded perspective view of the vicinity of the side plate 15;

FIG. 21 is a simplified diagram showing combined bodies 190 and 190a provided in power supply means 153 and 154 provided at both ends in the axial direction of the heating roller body 151, respectively.

FIG. 22 is a simplified electric circuit diagram relating to the sheet heating element 152.

FIG. 23 is a cross-sectional view showing a configuration of a journal 24 and a power supply unit 154 provided in association with the journal 24.

FIG. 24 is a left side view of the belt fixing device.

FIG. 25 is a circumferential development of the planar heating element 152 used in the embodiment shown in FIGS. 23 and 24.

26 is a sectional line X of the connecting means 231 in FIG.
It is sectional drawing seen from XVI-XXVI.

FIG. 27 is an exploded perspective view of the connection means 231.

FIG. 28 is an exploded perspective view showing first and second connection members 234 and 235 and an assembly member 233.

FIG. 29 is an exploded perspective view of a current collecting member 226 and its vicinity.

FIG. 30 is a partial cross-sectional view of still another embodiment of the present invention.

FIG. 31 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 32 shows experimental results of diffusion of a fixing temperature in the belt fixing device in the embodiment of FIGS.

FIG. 33 is a graph showing experimental results of heat retention in the embodiment of the present invention shown in FIGS. 1 to 22;

FIG. 34 shows an experimental result of a diffusion property of a fixing temperature in a conventional belt fixing device.

[Explanation of symbols]

 Reference Signs List 1 belt fixing device 2 fixing device main body 3 fixing roller 5 heating roller 6 belt 7 pressure roller 8 recording paper 63 belt meandering prevention means 66 insertion / removal hole 71 lid 72 auxiliary plate 73 support member 120 meandering detection member 123 belt contact member 125 rope Strip guide part 127 Meandering detection spring 132 Cable strip 151 Heating roller main body 152 Planar heating element 153, 154 Power supply means 155 Power cutoff means 156 Inner coating layer 157 Base material 158 Electrical resistor 159 Common connection section 160, 161 Terminal 162 Thermal fuse 163, 164 Conductive adhesive 184 Nut 185 Bolt 188 Bolt shaft 189 Bolt head 190 Combined body 192 Sleeve 195 Conductive ring 200 Current collecting member 206 Holding member 213 Flexible line 226 Current collecting member 234 First resistor 235 second Antibody 251 temperature fuse element

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takayuki Yoshida 3-2-1-15 Meiwadori, Hyogo-ku, Kobe-shi, Hyogo Inside BANDO CHEMICAL CO., LTD. (72) Inventor Nobuo Omae 3 Meiwa-dori, Hyogo-ku, Kobe-shi, Hyogo No. 2-15 Bando Chemical Co., Ltd. F-term (reference) 2H033 AA42 BA11 BA12 BA25 BA26 BA29 BA30 BA38 BB03 BB04 BB13 BB14 BB18 BB21 BB22 CA06 CA34 CA35 3K034 AA02 AA22 AA33 BA08 BA13 BB08 BB13 BC12 HA25 AA29 AA42 AA45 AA87 AA91 BA18 CA05 CA23 CA46 CA78 CB10 CE02 CE12 CE19 CE21 DA04 DA14 GA06

Claims (13)

[Claims] 1. A hollow metal heating roller main body, a planar heating element disposed in contact with an inner peripheral surface of the heating roller main body, and a pair of electric power supplies provided at both axial ends of the heating roller main body. A power supply means, one end of each power supply means being electrically connected to the planar heating element, and the other end being exposed from an end of the heating roller body; and an internal space of the heating roller body. And a power cutoff means interposed in the middle of the path of the power of the sheet heating element supplied from the power supply means, and shutting off when the sheet heating element has an abnormally high temperature. Heating roller. 2. The heating roller according to claim 1, wherein the power cut-off means is provided on the planar heating element near an axial end of the heating roller main body. 3. The heating roller according to claim 1, wherein the power cutoff means is interposed and connected between the planar heating element and the power supply means. 4. The heating roller body has a right cylindrical shape, and journals are respectively provided at both ends of the heating roller body. Each journal is provided at a flange fixed to both ends of the heating roller body, and at the flange. And a journal shaft portion that has the same axis as the heating roller body, extends outward in the axial direction of the heating roller body, and is supported by a bearing. The heating roller according to claim 1, further comprising an air hole communicating between the internal space and the outside. 5. The heating roller according to claim 4, wherein the air holes are formed only in the flange. 6. A heating roller body made of a hollow metal, (b) a planar heating element arranged in contact with an inner peripheral surface of the heating roller body, and (c) a heating element at both ends of the heating roller body. A journal provided for each of the journals, wherein each journal has a flange fixed to both ends of the heating roller main body, and a flange provided on the flange and having the same axis as the axis of the heating roller main body. (D) a pair of power supply means provided at both ends in the axial direction of the heating roller main body, wherein each power supply means comprises a journal. A combination of a metal bolt to be inserted and a metal nut screwed to the bolt, wherein one end of the combination is electrically connected to the sheet heating element, and the other end of the combination is heated. Low A combination of a bolt and a nut exposed from an end of the main body, and a combination provided around the axis of the heating roller body so as to be freely rotatable with the combination and electrically connected to the combination. Power supply means having a current collecting member for supplying, wherein the direction of the screw of the bolt of each combination and the nut screwed to the bolt is a direction tightened by rotation around the axis of the heating roller body. A heating roller comprising: 7. The power supply means includes a current collection ring electrically connected to the combination body outside the journal in the axial direction of the heating roller main body and formed in an annular shape around the axis of the heating roller main body. 7. The heating roller according to claim 6, wherein the current collecting member resiliently contacts the current collecting ring and slides. 8. The power supply means is held at the free end of the journal shaft so as to be rotatable with respect to the free end around the axis of the heating roller body, covers the current collecting ring, and is made of an electrically insulating material. The heating roller according to claim 7, further comprising a holding member having the holding member, a current collecting member attached to the holding member, and a flexible line for supplying electric power connected to the current collecting member. 9. The power supply unit according to claim 1, wherein the power supply unit has a current collector on the axis of the heating roller body, and the current collector is resiliently contacted with the current collector. Item 9. A heating roller according to any one of items 6 to 8. 10. A belt wrapping apparatus comprising: an endless belt; a plurality of belt transport rollers around which the belt is wound, the belt being rotatably supported; and a pressure roller which sandwiches and transports a sheet between the belts. One of the belt transport rollers is a heating roller, and the heating roller is disposed in contact with (a) a hollow metal heating roller body, and (b) an inner peripheral surface of the heating roller body. (C) journals provided at both ends of the heating roller main body, wherein each journal is provided with a flange fixed to both ends of the heating roller main body; A journal having the same axis as that of (a) and extending outward in the axial direction of the heating roller body and having a journal shaft portion supported by a bearing; and (d) an axis of the heating roller body. And a pair of power supply means provided at both ends of the power supply unit, wherein each power supply means is a combination of a metal bolt inserted into the journal and a metal nut screwed to the bolt, and One end is electrically connected to the planar heating element, and the other end of the combination is a combination of a bolt and a nut exposed from an end of the heating roller body; and the combination around the axis of the heating roller body. A current collecting member that is provided rotatably with respect to the body and supplies electric power in a state of being electrically connected to the combined body; and the bolt of each combined body and the nut screwed to the bolt. The direction of the screw includes power supply means that is tightened by rotation about the axis of the heating roller body.At least one of the journal shafts has a belt meandering preventing means for preventing belt meandering. The belt meandering preventing means is: (e) a meandering detection member, which is rotatably supported by the journal shaft portion, supported by the shaft end coaxially with the detection member main body, and faces the belt. A meandering detection member having a belt contact portion that comes into contact with the belt with: (f) the journal shaft supporting the meandering detection member,
(G) a roller supporting means that is displaceably supported in a predetermined displacement direction orthogonal to the axis of the heating roller; And a roller shaft end displacing means for displacing the shaft end supporting the meandering detecting member of the heating roller in the predetermined displacement direction. 11. A power supply means provided near the one journal shaft portion provided with a belt meandering prevention means is electrically connected to the combination at a position outside the journal in the axial direction of the heating roller main body. Has a current collecting ring formed annularly around the axis of the heating roller body, a current collecting member resiliently abuts and slides on this current collecting ring, and at the free end of the journal shaft, A holding member made of an electrically insulating material, which is rotatably held with the free end portion around the axis of the heating roller body, covers the current collecting ring, and has a current collecting member attached to the holding member; A flexible line for supplying electric power is connected to the current collecting member, and the combination of the power supply means disposed near the other journal shaft part where the belt meandering prevention means is not provided includes a shaft of the heating roller main body. Current collector on line And, this collector portions, a belt winding device, characterized in that the current collecting member is contacted to resiliently. 12. An electrically insulating and flexible film-shaped synthetic resin base material, formed on one surface of the base material, and supplied with electric power between both ends in a predetermined one direction. An electric resistor that generates heat, terminals formed on the one surface of the base material, and terminals respectively provided outward in the one direction from both ends of the electric resistor, at least one end of the electric resistor, And a power cut-off means interposed between the terminal and the power supply for cutting off when an abnormally high temperature is generated by the electric resistor. 13. A power cutoff means, comprising: a flat temperature fuse which blows at an abnormally high temperature; and a conductive adhesive which bonds the fuse to the at least one end of an electric resistor and the terminal. 13. The sheet heating element according to claim 12, comprising: