JP2008020643A - Method of manufacturing fixing roller, fixing roller and fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a fixing roller whereby an external layer endless member and an internal member can easily be assembled, and to provide a fixing roller and a fixing device. <P>SOLUTION: The fixing device 1 includes: a heat roller 10 for use as a heat rotation body; and a pressure roller for use as a pressure rotation body. The heat roller 10 includes: an elastic roller core member 20 having an elastic tube 22; and an external layer tube 30 having a conductive layer 31. A method for manufacturing the heat roller 10 includes: a step of injecting gas into the external layer tube 30; and a step of inserting the elastic roller core member 20 into the external layer tube 30 with the gas injected therein. The elastic roller core member 20 has a large-diameter part 23 and a small-diameter part 24. An empty space 25 is formed between the small-diameter part 24 of the elastic roller core member 20 and the external layer tube 30. A ventilation groove 26 is formed so as to extend from this empty space 25 to both of the axial ends of the elastic roller core member 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a fixing roller, a fixing roller, and a fixing device used in, for example, an image forming apparatus of an electrophotographic apparatus.

In a fixing device of an image forming apparatus, a technique is known that uses a fixing roller having a conductor layer and an elastic layer for at least one of a heating rotator and a pressure rotator (see, for example, Patent Document 1). . This fixing roller is configured by covering an outer periphery of an inner member including an elastic layer having a desired elastic force with an outer layer endless member including a conductor layer having high thermal conductivity. With this structure, both the function of maintaining the recording material in a heated state and the function of fixing the toner image on the recording material are provided.
JP 2005-49812 A JP 2005-31308 A

However, in the fixing roller having the above-described configuration, the manufacturing process may be complicated depending on the material and dimension setting of the inner member and the outer layer endless member. That is, when the inner member is inserted into the tubular outer layer endless member in order to cover the outer layer endless member on the outer periphery of the inner member, a repulsive force is generated between the inner member and the outer layer endless member. It becomes difficult.
SUMMARY An advantage of some aspects of the invention is that it provides a fixing roller manufacturing method, a fixing roller, and a fixing device in which an outer layer endless member and an inner member can be easily assembled.

A fixing roller manufacturing method according to an example of the present invention includes: an inner member having an elastic layer; and a tubular outer layer endless member having a conductor layer and supported at least partially on the outer peripheral surface of the inner member. A fixing roller manufacturing method comprising: a gas feeding step of feeding gas into the outer layer endless member; and the inner member inside the outer layer endless member in a state where gas is fed in the gas feeding step. And an insertion step of inserting.
A fixing roller according to another example of the present invention is a fixing roller manufactured by the above-described manufacturing method, wherein the outer layer endless member has a first region formed at both ends in the axial direction and a center in the axial direction. The inner member is formed at both ends in the axial direction of the elastic body layer and has a first outer diameter, and a large diameter portion of the large diameter portion. A small-diameter portion formed on the inner side in the axial direction and having a second outer diameter smaller than the first outer diameter, and the large-diameter portion is fixed to the first region of the outer-layer endless member, and the small-diameter portion A gap portion is formed between the gap portion and the second region of the outer layer endless member, and an air passage is formed from the gap portion to both axial ends of the inner member.
In addition to the above, the fixing roller according to another example of the present invention is characterized in that the air passage is formed on the outer peripheral surface of the large-diameter portion along a groove formed along the insertion direction in the insertion step. To do.
In addition to the above, a fixing roller according to another example of the present invention is characterized in that the outer layer endless member has a multi-layer structure including at least a conductor layer, an elastic body layer, and a release material layer.
The fixing device according to another example of the present invention is configured to melt the toner on the recording material by maintaining the recording material in an overheated state between the heating rotator and the pressure rotator, and A fixing device of an image forming apparatus for fixing a toner image, wherein at least one of the heating rotator and the pressure rotator is the fixing roller.

  According to the manufacturing method of the present invention, the outer layer endless member can be easily assembled to the inner member.

[First Embodiment]
A first embodiment of the present invention will be described below with reference to FIGS. In each figure, the configuration is appropriately enlarged, reduced or omitted.
FIG. 1 schematically shows an example of a fixing device according to the present embodiment. The fixing device 1 includes a heating roller 10 as a heating rotator and a pressure roller 40 as a pressure rotator. Note that the length of the heating roller 10 and the pressure roller 40 in the longitudinal direction (the depth direction in the drawing) is larger than the width of the sheet 50, and is configured to be, for example, about 330 mm. A heating device 53 is provided around the heating roller 10. The heating device 53 is, for example, an IH coil, and the heating device 53 generates a current for induction heating on the surface of the heating roller 10, whereby the surface of the heating roller 10 is heated to a predetermined temperature.

  The fixing device 1 is used, for example, in an image forming apparatus or the like, and maintains a sheet 50 as a recording material between a heating roller 10 and a pressure roller 40 in a heated state, and a toner 51 on the sheet 50. And a function of fixing the image of the toner 51 on the paper 50.

  The heating roller 10 as an example of the fixing roller shown in FIGS. 2 and 3 includes an elastic roller core member 20 as an inner member and an outer layer tube 30 as an outer layer endless member, and is configured in a columnar shape with a diameter of about 40 mm. ing. The elastic roller core member 20 includes a cored bar 21 and an elastic tube 22 as an elastic layer disposed on the outer periphery of the cored bar 21. The outer tube 30 has a multi-layer structure including a conductor layer 31, a solid rubber layer 32 as an elastic layer, and a release material layer 33.

  The cored bar 21 is formed in a columnar shape or a cylindrical shape, for example, by a steel material such as iron, aluminum, or stainless steel, or ceramic. The cored bar 21 is connected to a drive motor 52 shown in FIG. 1, and can be rotated in the direction of an arrow X, for example, about a rotation axis by driving the drive motor 52.

The elastic tube 22 of the present embodiment is bonded to the outer peripheral surface of the cored bar 21. The elastic tube 22 is formed from a sponge layer of silicone rubber foam, and is made of, for example, a material having a thermal conductivity of 0.25 W / mk or less, a hardness of 45 degrees or less, and an elastic modulus of 3.5 × 10 ⁻⁴ or less. It has the desired heat resistance, stretchability and elasticity.

  As shown in FIGS. 2, 3 and 5, the elastic tube 22 includes a large diameter portion 23 having a first outer diameter D1 at both ends in the axial direction, and a smaller inner diameter than the first outer diameter D1 at the center. A small-diameter portion 24 having two outer diameters D2 is provided. Here, for example, D1 is configured to be approximately 45.3 mm, and D2 is configured to be approximately 44 mm. In the natural state, the second outer diameter D2 is set to 96% or more and less than 100% of the first outer diameter D1.

  The inner surface 34a of the first region 34 of the outer layer tube 30 to be described later is bonded and fixed to the outer peripheral surface 23a of the large-diameter portion 23 at both ends through a heat-resistant adhesive having a heat-resistant temperature of 200 ° C. or more. 30 is supported by the elastic roller core member 20. In the natural state, the inner surface 35 a in the second region 35 of the outer layer tube 30 is separated from the outer peripheral surface 24 a of the small diameter portion 24, and the gap portion 25 is provided between the elastic tube 22 and the outer layer tube 30 at the center in the axial direction. Is formed.

  On the outer peripheral surface 23a of the large-diameter portion 23, a ventilation groove 26 as an example of a ventilation path is formed at two locations facing each other around the axis. The ventilation groove 26 is a recess having a V-shaped cross section, and is formed along the axial direction. The ventilation grooves 26 are formed so as to reach both end surfaces in the axial direction of the respective large diameter portions 23.

  That is, the ventilation groove 26 extends from the gap portion 25 through the outer peripheral surface 23a of the large diameter portion 23 and the both end surfaces 27 in the axial direction of the elastic roller core member 20 to the outside. Therefore, air can enter and exit between the gap portion 25 and the outside of the heating roller 10 through the inner surface 35 a in the second region 35 of the outer layer tube 30 and the ventilation groove 26.

  The outer tube 30 has a thin cylindrical shape including a first region 34 formed at both ends in the axial direction and a second region 35 formed at the center in the axial direction. The inner diameter of the outer layer tube 30 is configured to be approximately the same as the first outer diameter D1. The inner surface 34 a of the first region 34 is bonded to the outer peripheral surface 23 a of the large diameter portion 23. Thereby, the outer layer tube 30 is supported by the elastic roller core member 20.

  The conductor layer 31 located inside the outer tube 30 is made of a metal material having high thermal conductivity such as nickel, and has a thickness of about 10 μm. The conductor layer 31 maintains the heating state by the heating device 53.

  The solid rubber layer 32 is formed to a thickness of about 200 μm from a material having a high elastic coefficient such as heat-resistant silicone rubber, and is formed outside the conductor layer 31.

  The release material layer 33 is made of PFA or the like and has a thickness of about 30 μm, and is formed outside the solid rubber layer 32. The release material layer 33 is located on the outermost side of the heating roller 10 and has a function of preventing the toner 51 or the powder of the paper 50 from adhering to the nip portion N in contact with the paper 50 when incorporated in the fixing device 1. Have

  As shown in FIG. 1, the paper 50 is peeled from the heating roller 10 on the circumference of the heating roller 10 and on the downstream side in the rotation direction from the nip portion N that contacts the pressure roller 40 via the paper 50. A peeling claw 54 and a cleaning member 55 for removing dust such as toner 51 and paper waste are provided.

  On the other hand, the pressure roller 40 has an outer periphery of a core member 41 covered with an elastic member 42 made of an elastic material such as silicone or fluorine rubber, and has the same diameter as the heating roller 10. Inside the pressure roller 40, a heater lamp 43 for heating is provided. The pressure roller 40 is pressed against the heating roller 10 at a predetermined pressure by receiving a predetermined pressure from a pressure mechanism 44 such as a pressure spring. For this reason, a nip portion N having a predetermined width is formed at a position where the heating roller 10 and the pressure roller 40 are in contact with each other.

Hereinafter, the operation of the fixing device 1 according to the present embodiment will be briefly described with reference to FIG.
When the heating roller 10 is rotated in the arrow X direction by the drive motor 52, the pressure roller 40 is rotated in the arrow Y direction as the heating roller 10 rotates. The heating roller 10 and the pressure roller 40 are heated to a predetermined temperature by the heating device 53 and the heater lamp 43. The predetermined temperature varies depending on the material of the toner 51, but is set to 180 ° C. in this embodiment. As the sheet 50 holding the toner 51 with the rotation is conveyed to the nip portion N between the heating roller 10 and the pressure roller 40 whose temperature has been increased, the toner 51 on the sheet 50 is melted. The melted toner 51 is fixed to the paper 50 by being pressed onto the paper 50. Here, at the time of heating and cooling, the elastic roller core member 20 and the outer tube 30 of the heating roller 10 expand and contract, respectively. At this time, the air gaps 25 are present, and air can enter and exit due to the presence of the ventilation grooves 26, so that each layer is smoothly expanded and contracted.

Next, a method for manufacturing the heating roller 10 according to the present embodiment will be described.
First, as shown in FIG. 4, a stepless elastic roller core member 20a is configured by inserting a core metal 21 into a cylindrical elastic tube 22a having a first outer diameter D1 and bonding and fixing them to each other. .

  Next, the elastic tube 22a is processed into a predetermined shape by using a polishing machine or the like to form a stepped elastic roller core member 20 as shown in FIG. That is, the central portion in the axial direction of the outer peripheral surface of the elastic tube 22a having the first outer diameter D1 is shaved by a predetermined amount to obtain the second outer diameter D2, and the small diameter portion 24 is formed.

  Further, a ventilation groove 26 having a V-shaped cross section is formed on the outer peripheral surface 23a of the large diameter portion 23 at both ends by cutting, polishing, cutting or the like using an engraving blade or the like. Thus, the elastic roller core member 20 having a predetermined shape is completed. The length X1 of the small diameter portion 24 of the outer diameter D2 is preferably larger than the image forming range in the paper width direction of the paper 50 to be used.

  Next, as shown in FIGS. 6 and 7, a heat-resistant adhesive such as a silicone adhesive is applied to the outer peripheral surface 23a of the large-diameter portion 23 of the elastic roller core member 20, and a covering material 66 such as a film is applied thereon. Put on. Next, the outer layer tube 30 is set on the insertion jig 60. At this time, the outer wrap tube 30 may be covered with a protective wrap material (not shown). The insertion jig 60 includes a cylindrical support member 61 and is connected to an air feeder (not shown) via an air valve 62.

  Next, in the gas feeding step, air is fed into one end side of the outer tube 30, that is, from the opening on the lower side in the drawing, by the air feeder of the insertion jig 60. During this gas feeding process, the elastic roller core member 20 is inserted along the axial direction into the inside from the other end side of the outer layer tube 30 in a state where air is fed, that is, the opening on the upper end side in the drawing.

  After the elastic roller core member 20 is inserted, the covering material 66 covered on the outer peripheral surface 23a as the bonding portion and the wrapping material wound around the outer tube 30 are removed. Next, the position of the outer tube 30 is adjusted, and the adhesive is cured in a drying furnace. Finally, both end surfaces of the heating roller 10 are cut by a round blade cutter or the like. Thus, the heating roller 10 is completed.

The manufacturing method of the heating roller 10, the heating roller 10, and the fixing device 1 according to the present embodiment have the following effects.
In the gas feeding process, by sending air into the outer layer tube 30, the outer layer tube 30 is expanded, the inner diameter is enlarged, and the inner cross-section is adjusted to a perfect circle, so that the insertion operation of the elastic roller core member 20 is easy. It becomes.

  The ventilation groove 26 formed in the outer circumferential surface 23a of the gap portion 25 and the large diameter portion 23 reduces the area in contact with the outer layer tube 30 and facilitates the insertion operation because air flows smoothly. Furthermore, since the ventilation groove 26 is formed along the same axial direction as the insertion direction, it is easy to insert.

  Further, the gap 25 and the ventilation groove 26 also have a function of smoothly expanding and contracting due to heating and cooling when used as the fixing device 1. That is, since air can freely enter and exit through the gap 25 and the ventilation groove 26, the gap 25 is prevented from being in a negative pressure state, and the elastic roller core member 20 and the outer tube 30 are different from each other due to the difference in expansion speed. Interference can be prevented. As a result, deformation of the outer layer tube 30 caused by these can also be prevented.

  Further, by covering the adhesive portion formed on the outer peripheral surface 23a of the large-diameter portion 23 during insertion, the adhesive is prevented from moving, and the adhesive adheres to another site, or the ventilation groove 26. Can be prevented from being filled with an adhesive. Further, since the second outer diameter D2 is 96% or more of the first outer diameter D1, it is possible to prevent the step between the large diameter portion 23 and the small diameter portion 24 from affecting the printing accuracy.

[Second Embodiment]
Next, an elastic roller core member 70 as an inner member according to the second embodiment of the present invention will be described. In addition, since it is the same as that of the said 1st Embodiment except the structure of a ventilation path, description is abbreviate | omitted. 8 and 9 show an elastic roller core member 70 according to the second embodiment.

  In the elastic roller core member 70 of the present embodiment, a vent hole 76 is formed as a vent path. The vent hole 76 extends from the outer peripheral surface 74a of the small diameter portion 74 toward the axial center, and reaches the cored bar 71. The first hole 76a is formed from the end of the first hole 76a to the cored bar 71. The second hole 76 b extends along the axial direction inside and reaches both end faces 77. That is, the air holes 76 communicate with the outside through the gap 75 to both end surfaces of the cored bar 71 in the axial direction.

  A hollow core member such as a sleeve pipe may be used in place of the columnar cored bar. In this case, it is not necessary to form the second hole portion 76b along the axial direction, and only the first hole portion 76a extending from the outer peripheral surface of the small diameter portion 74 to the hollow portion of the cored bar 71 may be formed.

  In addition, the manufacturing method of the heating roller using the elastic roller core member 70 according to the present embodiment is a small diameter instead of forming the ventilation groove 26 as the ventilation path in the manufacturing method of the heating roller 10 according to the first embodiment described above. A vent hole 76 extending from the outer peripheral surface 74 a of the portion 74 to the both end surfaces 77 through the core bar 71 is formed. Other processes are the same as those in the first embodiment.

  Also in this embodiment, the same effect as that of the heating roller 10 according to the first embodiment described above can be obtained. That is, since the elastic roller core member 70 can be inserted in a state where the outer layer tube 30 is maintained in a perfect circle by feeding air, it can be easily assembled. Furthermore, it can insert smoothly by the space | gap part 75 and the ventilation hole 76. FIG.

[Third Embodiment]
Next, an elastic roller core member 80 as an inner member according to the third embodiment of the present invention will be described. In addition, since it is the same as that of the said 1st Embodiment except the structure of a ventilation path, description is abbreviate | omitted. 10 and 11 show an elastic roller core member 80 according to the third embodiment.

  In the elastic roller core member 80 according to the present embodiment, the large diameter portion 83 and the small diameter portion 84 are divided. That is, the large-diameter portion 83 at both ends in the axial direction of the elastic tube 82 and the small-diameter portion 84 at the center in the axial direction are formed separately, and the large-diameter portion 83 and the small-diameter portion 84 reach the entire circumference of the cored bar 81. It is separated.

  A vent hole 86 is formed in the cored bar 81 at the separated portion. The ventilation hole 86 extends along the axial direction inside the cored bar 81 from the end of the first hole 86a and a first hole 86a formed from the outer peripheral surface of the cored bar 81 toward the axial center. The second hole portion 86b reaches both end surfaces. That is, the vent hole 86 communicates from the gap portion 85 through the both end surfaces of the cored bar 81 to the outside.

  Note that a core member such as a hollow sleeve pipe may be used in place of the columnar core 81. In this case, since it is not necessary to form the second hole 86b along the axial direction, it is easy to form.

  Also in this embodiment, the same effect as the manufacturing method of the heating roller 10 according to the first embodiment described above can be obtained. That is, since the elastic roller core member 80 can be inserted in a state where air is fed and the outer layer tube 30 is maintained in a perfect circle shape, assembly is facilitated. Further, the insertion is smooth by the gap 85 and the vent hole 86.

  In carrying out the present invention, it goes without saying that the constituent elements of the present invention, such as the material, dimensions, and specific shape of each component, can be variously changed without departing from the spirit of the invention. For example, the number of ventilation paths such as the ventilation grooves 26 and the ventilation holes 76 and 86 is not limited to the above embodiments, and any number of ventilation paths can be applied.

  Further, the configuration of the heating roller 10 and the pressure roller 40 in each of the above embodiments may be reversed. Further, both of the heating roller 10 and the pressure roller 40 may be constituted by a fixing roller having a conductor layer and an elastic layer similar to those of the heating roller 10 of the above embodiment.

  Furthermore, although the case where the ventilation groove 26 is formed along the axial direction has been described, it may be formed in a spiral shape. In this case, vibration caused by a step due to the ventilation groove 26 in the nip portion N can be reduced.

  Further, only the main configuration of the fixing device 1 has been described, but various components such as a temperature detector may be provided. Further, as the heating device 53, various heating devices such as a halogen lamp can be used in addition to the IH coil of the above embodiment. Furthermore, although an example of a fixing device that can be used in a color image forming apparatus has been shown, the present invention can also be used in a facsimile machine that uses toner.

  In addition to the configuration of each of the above embodiments, the outer diameter D2 of the small diameter portion 24 of the elastic roller core member 20 may be continuously changed along the axial direction. For example, when the paper is discharged from the nip portion by gradually decreasing the outer diameter from the both ends in the axial direction toward the center like the small diameter portion 94 of the elastic roller core member 90 as the inner member shown in FIG. The force toward the corner of the paper acts, and the occurrence of wrinkling of the paper can be prevented.

In addition, although the case where it applies to 1st Embodiment is shown in the figure, it is applicable also to 2nd Embodiment and 3rd Embodiment. On the contrary, the outer diameter may be gradually decreased from the center in the axial direction toward both ends. In this case, it is possible to prevent the occurrence of curling, which is a change in curvature in the direction in which the paper 50 is conveyed. In addition, when continuously changing these outer diameters D2, it is preferable to apply the reverse characteristics to the pressure roller 40 which opposes.
Of course, various modifications can be made without departing from the scope of the present invention.

1 is a front view showing an outline of a fixing device according to a first embodiment of the present invention. Sectional drawing of the heating roller concerning 1st Embodiment of this invention. Sectional drawing of the heating roller concerning 1st Embodiment of this invention. The perspective view of the stepless elastic roller core member concerning 1st Embodiment of this invention. The perspective view of the elastic roller core member concerning 1st Embodiment of this invention. Sectional drawing which shows the gas feeding process in the manufacturing method of the heating roller concerning 1st Embodiment of this invention. Sectional drawing which shows the insertion process in the manufacturing method. The side view of the elastic roller core member concerning 2nd Embodiment of this invention. The front view of the elastic roller core member. The side view of the elastic roller core member concerning 3rd Embodiment of this invention. The front view of the elastic roller core member. The side view of the elastic roller core member concerning other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fixing device, 10 ... Heating roller (fixing roller),
20, 70, 80, 90 ... elastic roller core member (inner member),
22 ... elastic tube (elastic body layer), 23 ... large diameter portion, 24 ... small diameter portion, 25 ... gap portion,
26 ... Ventilation groove (air passage), 27 ... Both end faces, 30 ... Outer tube (outer layer endless member), 31 ... Conductor layer, 32 ... Solid rubber layer (elastic body layer), 33 ... Release material layer, 34 ... First Area,
35 ... second region, 40 ... pressure roller, 44 ... pressure mechanism, 50 ... paper, 51 ... toner,
53 ... heating device, 76, 86 ... vent (ventilation groove).

Claims (5)

A fixing roller manufacturing method comprising: an inner member having an elastic layer; and a tubular outer layer endless member having a conductor layer and supported on at least a part of the outer peripheral surface of the inner member,
A gas feeding step of feeding gas into the outer layer endless member;
A fixing roller manufacturing method comprising: an inserting step of inserting the inner member into the outer layer endless member in a state where the gas is fed in the gas feeding step. A fixing roller manufactured by the manufacturing method according to claim 1,
The outer layer endless member is configured in a cylindrical shape including a first region formed at both ends in the axial direction and a second region formed at the center in the axial direction,
The inner member is formed at both ends in the axial direction of the elastic layer and has a large-diameter portion having a first outer diameter, and is formed on the inner side in the axial direction of the large-diameter portion and is smaller than the first outer diameter. A small diameter portion having an outer diameter of 2,
The large diameter portion is fixed to the first region of the outer layer endless member,
A gap is formed between the small diameter portion and the second region of the outer layer endless member,
A fixing roller, wherein an air passage extending from the gap to both ends of the inner member in the axial direction is formed.   The fixing roller according to claim 3, wherein the air passage is formed of a groove formed along an insertion direction in the insertion step on an outer peripheral surface of the large diameter portion.   The fixing roller according to claim 3, wherein the outer layer endless member has a multi-layer structure including at least a conductor layer, an elastic body layer, and a release material layer. A fixing device of an image forming apparatus that maintains a recording material in an overheated state between a heating rotator and a pressure rotator, melts the toner on the recording material, and fixes the toner image on the recording material. Because
The fixing device according to claim 2, wherein at least one of the heating rotator and the pressure rotator is the fixing roller according to claim 2.

Images