JP2007047321A - Roller core bar, manufacturing method thereof, fixing roller, fixing apparatus, and image forming apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin fixing roller of high strength free from deformation such as dent and bend, capable of coping with a high nip pressure required to attain high image quality and stable fixation, and to provide a roller core bar capable of attaining the aforesaid fixing roller. <P>SOLUTION: Regarding the hollow cylindrical roller core bar, a plurality of ribs are arranged at the inside surface of the roller core bar, and among the ribs, a ring-like reinforcing member is arranged in between at least a pair of two adjacent ribs in contact with the two ribs. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a roller core that can be suitably used for a fixing roller used in a fixing device (heat fixing device) used in an electrophotographic copying machine, a printer, a facsimile, and the like, a manufacturing method thereof, a fixing roller, The present invention relates to a fixing device.

  When printing or copying using an image forming apparatus such as an electrophotographic copying machine, a laser printer, or a facsimile, the visible image (toner image) on the transfer material (recording paper) is heated at the final stage. It is fixed on the recording paper by melting. For example, in an electrophotographic copying machine, a process of forming an electrostatic latent image by performing image exposure on an image carrier, a process of forming a visible image by attaching toner to the electrostatic latent image on the image carrier, an image The process of transferring the toner image on the carrier onto the recording paper and separating the recording paper from the image carrier, and fixing the unfixed toner image transferred onto the recording paper on the recording paper by heating and melting. Copying is performed sequentially through the process.

  Conventionally, an unfixed toner image transferred onto a recording sheet is generally fixed by a thermal fixing method. According to this heat fixing method, a fixing roller is used in which a heater such as a halogen lamp is disposed in the hollow portion of the cylindrical metal core along the rotation axis and heated from the inside of the cylindrical metal core by the radiant heat. ing.

  FIG. 13 is an explanatory diagram of a conventional fixing device 210. As shown in FIG. 13, the fixing roller 201 is in contact with the pressure roller 202 subjected to the pressing action of the spring 203. The recording paper 205 on which the toner image formed with the toner 206 is transferred from the photosensitive member is inserted between the fixing roller 201 and the pressure roller 202 so that the toner image contacts the fixing roller 201. While the recording paper 205 passes between the fixing roller 201 and the pressure roller 202, the toner 206 that forms a toner image is heated and melted and pressed against the recording paper 205. As a result, the toner image is transferred to the recording paper. Fixed to 205.

  Here, in order to speed up image fixing, it was possible to shorten the warm-up time by means such as preheating the fixing roller in advance or increasing the capacity of a halogen heater as a heating source. There is a demand for image fixing without waiting time while aiming at zero power consumption.

  As one countermeasure against such a requirement, it is conceivable to reduce the thickness of the fixing roller so as to accelerate the heat transfer from the heat source inside the roller to the surface layer.

  However, when the wall thickness is reduced, the following problems occur. That is, both the fixing roller 201 and the pressure roller 201 are held at both ends and are urged so as to be in close contact with each other by a spring or the like. At this time, the thickness of the fixing roller is reduced, so that the fixing roller is moved to FIG. 14A (cross-sectional view in a plane perpendicular to the axis of the fixing roller 201) and FIG. And a sectional view in a plane including the axis of the pressure roller 202). The main deformation is bending due to bending force and crushing due to being thin. This deformation is combined to form a displacement on the lower surface, causing unevenness in the axial direction at the contact portion (nip portion) between the fixing roller and the pressure roller, which causes a fixing failure.

  Here, crushing represents deformation in a cross section perpendicular to the axis of the roller, and refers to a state in which, for example, a pipe having a perfect circular cross section is crushed into an ellipse (see FIG. 14A). On the other hand, the bending is a bending of the roller, and indicates a state when a straight pipe is bent (see FIG. 14B).

  In order to suppress such bending and crushing, convex portions (ribs) are provided on the inner peripheral surface of the fixing roller in a circumferential shape (see FIG. 15 in a cross section including the rotation shaft of such a roller core for the fixing roller). Although the effect on the deformation (deflection) in the axial direction is small due to the model cross-sectional view), it has been verified that the effect of reducing crushing is large and put into practical use.

  However, it is difficult to increase the height of the rib in the rib integrated with the metal core due to restrictions on the manufacturing method. To prevent the above-mentioned crushing and bending more completely, the width of the rib can be increased or the number of the ribs can be increased. Although measures such as an increase are taken, there is a problem that this method increases the heat capacity of the core metal and reduces the merit of thinning.

  Further, in the method disclosed in Japanese Patent Laid-Open No. 2002-196605 (Patent Document 1), a technique for fixing a cylindrical ring inside a fixing roller has been proposed. In this technique, a part where the cylindrical ring is set is proposed. Because the thickness of the fixing roller is thinner than other locations, if the roller is heated and pressurized while rotating, the cylindrical ring is set, and the thin portion of the fixing roller is subjected to concentrated stress and is damaged. Therefore, there is a problem that the average thickness of the entire fixing roller cannot be sufficiently reduced.

However, it is desired to realize a higher nip pressure between the fixing roller and the pressure roller in order to improve the image quality and stabilize the fixing performance.
JP 2002-196605 A

  The present invention improves the above-described conventional problems, that is, can cope with a high nip pressure desired for high image quality and stable fixing properties, and does not cause deformation such as crushing and bending. An object of the present invention is to provide a thin fixing roller having high strength and a roller core that enables such a fixing roller.

  In order to solve the above-described problems, the roller cored bar of the present invention is a hollow cylindrical roller cored bar as set forth in claim 1, wherein a plurality of ribs are provided on the inner surface of the roller cored bar. A ring-shaped reinforcing member is disposed between at least one pair of two adjacent ribs in contact with the two ribs.

  Furthermore, the roller cored bar of the present invention is characterized in that, as described in claim 2, in the roller cored bar according to claim 1, chamfering is performed on both side surfaces of the inner surface of the ring-shaped reinforcing member. To do.

  According to a third aspect of the present invention, there is provided a method of manufacturing a roller cored bar, wherein a plurality of ribs are provided on an inner surface of the roller cored bar, and at least one set of two ribs adjacent to each other is provided. A method of manufacturing a hollow cylindrical roller cored bar in which a ring-shaped reinforcing member is disposed in contact with both of the two ribs, wherein the ring-shaped reinforcing member is disposed inside the thin-walled cylindrical structure. A step of forming a rib in contact with the ring-shaped reinforcing member on the inner side surface of the thin cylindrical structure by inserting a pressing member against the outer side surface of the thin cylindrical structure after inserting so that the rotational symmetry axes coincide with each other; It is characterized by having.

  Further, according to a method for manufacturing a roller cored bar of the present invention, as described in claim 4, in the roller cored bar according to claim 3, both the two ribs are formed after the ring-shaped reinforcing member is inserted. Features.

  According to a fifth aspect of the present invention, a fixing roller includes the roller cored bar according to the first or second aspect.

  According to a sixth aspect of the present invention, the fixing device includes the fixing roller according to the fifth aspect.

  According to a seventh aspect of the present invention, the image forming apparatus includes the fixing device according to the sixth aspect.

  According to the roller cored bar of the present invention according to claim 1, in addition to the reinforcing effect by the ring-shaped reinforcing member, the reinforcing effect by the rib provided on the roller cored bar is also obtained, and the ring-shaped reinforcing by the rib The member is prevented in advance from rotating in the roller mandrel, so that the reinforcing effect by the ring-shaped reinforcing member is not lost, and a thin and high strength fixing roller can be realized. .

  According to the roller cored bar of the present invention according to claim 2, the roller cored bar itself can be easily manufactured.

  According to the method for manufacturing a roller cored bar according to claim 3, in addition to the reinforcing effect by the ring-shaped reinforcing member, the reinforcing effect by the rib provided on the roller cored bar is obtained, and the ring-shaped reinforcing metal is obtained by the rib. The reinforcing member is prevented from rotating in the roller core in advance, so that the reinforcing effect by the ring-shaped reinforcing member is not lost, and a thin but high strength fixing roller is possible. Become.

  According to the roller cored bar manufacturing method of the present invention according to claim 4, the roller cored bar according to claim 1 can be manufactured with high productivity.

  According to the fixing roller of the present invention according to claim 5, deformation such as crushing and bending, which can cope with a higher nip pressure, which is desired for high image quality and stability of fixing, does not occur. A thin fixing roller with high strength can be obtained.

  According to the fixing device of the present invention according to claim 6, it is possible to realize a higher nip pressure desired for high image quality and stabilization of fixing performance, and power consumption by preheating is small. Image fixing without waiting time is possible.

  According to the image forming apparatus of the present invention according to claim 7, power consumption due to preheating is small, and image formation without waiting time is possible.

  The present invention will be described below with reference to the drawings.

  FIG. 1 shows a model cross-sectional view of a cross section including a rotation shaft of a roller core A according to the present invention.

  In the hollow cylindrical roller metal core A, a plurality of (in this example, 12) ribs are provided on the inner surface, and among these ribs, between the two adjacent ribs A1 and A2, rib A3 and rib Between the ribs A4 and between the ribs A5 and A6, ring-shaped reinforcing members B (three) are arranged in contact with the two ribs.

  With such a configuration, in such a fixing roller using the roller metal core A, in addition to the reinforcing effect of the ring-shaped reinforcing member B, ribs (A1 to A6 provided on the roller metal core, which are further ring-shaped in this series) The reinforcing effect by the six ribs not in contact with the reinforcing member B is also obtained, and the rib-shaped reinforcing member B rotates within the roller core by the rib (the axis of the ring-shaped reinforcing member B and The state in which the axis of the roller core A is 90 ° is prevented in advance, and therefore, the reinforcing effect of the ring-shaped reinforcing member B is not lost, so that the fixing is thin but has high strength. The roller becomes possible, and at that time, it is possible to cope with higher nip pressure, which is desired for high image quality and stability of fixing, and it does not cause deformation such as crushing and bending, and it is thin with high strength Fixing low To become.

  Furthermore, with such a fixing device using a fixing roller, it is possible to achieve a higher nip pressure, which is desired for higher image quality and stability of the fixing performance, and power consumption due to preheating is small. Image fixing without time is possible.

  Such a roller metal core A can be manufactured as follows, for example.

  First, both ends of a hollow cylindrical cylindrical material 1 made of a metal material such as aluminum or an aluminum alloy are held by jigs 2 and 3, but at this time, as shown in the model cross-sectional view of FIG. The ring-shaped reinforcing member B is inserted into a predetermined position in the cylindrical member 1 by the reinforcing ring holder 2 a attached to the cylindrical member 1.

  The material of the ring-shaped reinforcing member B is preferably made of a material having the same linear expansion coefficient as that of the cylindrical material 1. Usually, the same material as that of the cylindrical material 1 is used.

  The reinforcing ring holder 2a includes a holding small-diameter portion 2a1 having an inner diameter slightly smaller than the inner diameter of the ring-shaped reinforcing member B, and a large-diameter portion 2a2 that is thicker than the inner diameter of the ring-shaped reinforcing member B and larger than the inner diameter of the cylindrical member 1. The ring-shaped reinforcing member B is held in contact with the stepped wall 2a3 between the holding small-diameter portion 2a1 and the large-diameter portion 2a2. Here, as shown in a model enlarged cross-sectional view (FIG. 3) in the vicinity of the ring-shaped reinforcing member B when the ring-shaped reinforcing member B is inserted into a predetermined position in the cylindrical member 1 by the reinforcing ring holder 2a. The ring-shaped reinforcing member B is held by the holding small-diameter portion 2a1 in contact with the stepped wall portion 2a3 of the large-diameter portion 2a2.

  At this time, one end is fixed to the reinforcing ring holder 2a by a reinforcing member holding leaf spring holding space 2a4 provided so that a part of the holding small diameter portion 2a1 of the large diameter portion 2a2 has the same diameter as the holding small diameter portion 2a1. The other end is a free end 2a51 on the holding small-diameter portion 2a1 side, and the free end 2a51 is once bent in the radial direction of the reinforcing ring holder 2a. Since the reinforcing member B is held in contact with the holding small-diameter portion 2a1 and the step wall portion 2a3 of the large-diameter portion 2a2, the ring-shaped reinforcing member B does not easily come out of the holding small-diameter portion 2a1. . Here, the inner surface of the ring-shaped reinforcing member B is chamfered, for example, as shown in FIG. 3, a C chamfer (C: chamfered portion is indicated as B1) that is a chamfer by a straight line (usually 45 °), or a curved surface When the round chamfering is made, the ring-shaped reinforcing member B is set on the holding small-diameter portion 2a1 and, as will be described later, the holding small-diameter portion 2a1 is extracted from the ring-shaped reinforcing member B. Further, when these chamfers are applied to both side surfaces of the inner surface of the ring-shaped reinforcing member B, the ring-shaped reinforcing member when the ring-shaped reinforcing member B is set to the holding small-diameter portion 2a1. These effects can be obtained without depending on the direction of B.

  Although the free end 2a51 of the holding leaf spring 2a5 is bent in the radial direction of the reinforcing ring holder 2a, the further tip 2a52 of the free end 2a51 is further away from the tip of the holding small-diameter portion 2a1. Since it is bent to the axial direction side, the ring-shaped reinforcing member B can be easily set on the holding small diameter portion 2a1.

  As shown in FIG. 4, the spinning roller 4 is provided on the outer surface of the cylindrical member 1 in a state where the ring-shaped reinforcing member B is held at a predetermined position in the cylindrical member 1 by the reinforcing ring holder 2a. Press against. At this time, the ring-shaped reinforcing member B is positioned between the two disc-shaped indenters 4 a of the spinning roller 3, and the pressing of the spinning roller 4 against the outer surface of the cylindrical material 1 is continued, while the cylindrical material 1 And the spinning roller 4 is rotated together.

  As a result, the cylindrical member 1 is deformed, and two ribs 1 a in contact with the ring-shaped reinforcing member B are formed on both sides of the ring-shaped reinforcing member B. At this time, as shown in FIG. 4, two grooves 1b are formed on the outer surface of the cylindrical member 1 corresponding to these two ribs by two (two series) disk-shaped indenters 4a of the spinning roller 4. The

  Thereafter, the reinforcing ring holder 2a is removed from the cylindrical material 1, and the jigs 2 and 3 are removed. At this time, the ring-shaped reinforcing member B is pulled out from the reinforcing ring holder 2a. At this time, since both sides of the ring-shaped reinforcing member B are held in contact with the two ribs 1a as described above. The ring-shaped reinforcing member B is deformed at the free end 2a51 of the holding leaf spring 2a5 so as to be disengaged from the holding small-diameter portion 2a1 and remains inside the cylindrical member 1.

  Thereafter, as shown in FIG. 5 as a model, the outer surface of the cylindrical material 1 is cut with a cutting tool or the like to be processed to a predetermined thickness and formed on the outer surface of the cylindrical material 1. After that, the groove 1b is removed, and thereafter, as in the conventional roller core bar manufacturing method, both ends are reduced in diameter as necessary to obtain the roller core bar according to the present invention.

  FIG. 6 shows an enlarged cross-sectional view of the model in the vicinity of the ring-shaped reinforcing member B of the roller metal core A ′ according to the present invention obtained as described above. From this figure, the roller cored bar A ′ according to the present invention is a hollow cylindrical roller cored bar, and a plurality of ribs are provided on the inner side surface of the roller cored bar. It can be seen that the roller cored bar is provided with a ring-shaped reinforcing member B in contact with these two ribs 1a.

  In the above example, only one ring-shaped reinforcing member B is arranged inside the roller core, and a ring-shaped reinforcing member is disposed between a pair of two adjacent ribs in contact with the two ribs. An example of a roller cored bar is shown. For example, the case of a roller cored bar in which four ring-shaped reinforcing members B are arranged on the inner side of the roller cored bar is used as a model cross-sectional view of FIGS. I will explain.

  In FIG. 7, both ends of the cylindrical member 1 are held by jigs 2 and 2 '. At this time, two ring-shaped reinforcing members B are inserted into predetermined positions in the cylindrical member 1 by the reinforcing ring holders 2a and 2a 'attached to the jigs 2 and 2', respectively, The model shows a state where the spinning roller 4 is pressed and rotated so that one ring-shaped reinforcing member B is positioned between two disc-shaped indenters 4a. Thus, by inserting the reinforcing ring B from both ends of the cylindrical material 1 into the inside, it is possible to efficiently perform a process of inserting a plurality of reinforcing rings into the inside and forming ribs on both sides thereof.

  Next, as shown in FIG. 8, the reinforcing ring holders 2a and 2a ′ and the jigs 2 and 2 ′ are removed, and as shown in FIG. 9, two ring-shaped reinforcing members B already set in the cylindrical member 1 are used. The reinforcing member 2a, 2a 'having a short protrusion from the jigs 2, 2' so that the cylindrical member 1 can be set at a predetermined position on the opening side of the cylindrical member 1 is used. A ring-shaped reinforcing member B is inserted into each of the openings, one at a time, inside the cylindrical member 1, and on the outer surface of the cylindrical member 1, a newly inserted ring-shaped member is inserted between the two disc-shaped indenters 4 a. The spinning roller 4 is pressed and rotated so that the reinforcing member B is positioned, and two ribs are formed on both sides of the ring-shaped reinforcing member so as to contact the ring-shaped reinforcing member. Reinforcing ring holders 2a and 2a 'attached to Remove (see Figure 10). In this way, by adjusting the protruding amount of the reinforcing ring holder from the jig, a plurality of ring-shaped reinforcing members can be set at any position inside the cylindrical member 1.

  Further, the outer surface of the cylindrical material 1 is cut with a cutting tool or the like so as to have a predetermined thickness, and the groove 1b formed on the outer surface of the cylindrical material 1 is shown in FIG. (Roller mandrel intermediate A ″), and then, as in the conventional roller mandrel manufacturing method, a journal for mounting a bearing and a gear for driving is formed by drawing such as swaging. The roller cored bar according to the invention is used.

  After roughening the outer surface of such a thin roller cored bar according to the present invention by sandblasting, a primer is applied to the outer surface of the thinned cored bar and dried in an atmosphere of 100 to 150 ° C., Then, the surface of the primer is coated with a powdered fluororesin paint, and is baked for 20 to 40 minutes in an atmosphere at or above the melting point of the fluororesin, preferably at 360 ° C or above, to form a fluororesin film. Since the fluororesin film thus obtained has a rough surface, the toner formed on the transfer paper cannot be fixed satisfactorily and high quality image quality cannot be obtained. Therefore, the fluororesin coating is preferably finished smoothly.

  As fluororesin paint, perfluoroalkoxy resin (hereinafter referred to as “PFA”) and tetrafluoroethylene resin (hereinafter referred to as “PTFE”) are generally used. Since it is possible, the fluororesin paint can be reused by painting-recovery. The fixing roller according to the present invention thus obtained is desired for high image quality and stability of fixing, and can cope with a higher nip pressure, and does not undergo deformation such as crushing or bending. It is a thin fixing roller that has high strength and can significantly shorten the rise time.

  The inner surface of the fixing roller is black as necessary so that the radiation heat from the halogen lamp can be efficiently absorbed. In that case, for example, a black paint is applied in any of the above steps, and 250 to Bake at 300 ° C. for 1 to 3 hours.

  In the case of the roller core A according to the present invention shown in FIG. 1, six ribs that are not in contact with the ring-shaped reinforcing member B are provided. The rib can be formed in the same manner as the rib in contact with the ring-shaped reinforcing member B by using a spinning roller having a single disc-shaped indenter without inserting the reinforcing member into the cylindrical material.

  In addition, the number of ribs that are in contact with the ring-shaped reinforcing member B and the number of ribs that are not in contact with the ring-shaped reinforcing member B and the arrangement locations are appropriately adjusted according to the required performance such as strength and rigidity required for the fixing roller. .

  Here, as shown in FIG. 12, the fixing device 110 of the present invention has at least a fixing roller 10 and a pressure roller 112 provided so as to be in contact with the fixing roller 10. The fixing device 110 according to the present invention includes the fixing roller 10 made of the roller cored bar according to the present invention. As described above, when the fixing device 110 of the present invention has the fixing roller 10 made of the roller core according to the present invention, the rise time is significantly shortened, so that the image quality and the fixing property are stabilized. A desired high nip pressure can be realized, power consumption by preheating is small, and an image can be fixed without a waiting time such as a rise time.

  Further, as shown in FIG. 12, the image forming apparatus 100 of the present invention includes a fixing device 110 according to the present invention. As described above, when the image forming apparatus 100 according to the present invention includes the fixing device according to the present invention, a uniform image without unevenness can be formed.

  As shown in FIG. 12, the image forming apparatus 100 of the present invention includes a photosensitive drum 101 on which an electrostatic latent image is formed, a charging roller 102 that performs charging processing in contact with the photosensitive drum 101, and a laser beam. And the like, the developing roller 104 for attaching the toner to the electrostatic latent image on the photosensitive drum 101, the power pack 105 for applying a DC voltage to the charging roller 102, and the toner image on the photosensitive drum 101 on the recording paper A transfer roller 106 that performs transfer processing to 107, a cleaning device 108 that cleans the photosensitive drum 101 after the transfer processing, a surface potential meter 109 that measures the surface potential of the photosensitive drum 101, and the fixing roller 10 and the pressure roller The roller-type heat fixing device 110 is composed of 112.

  In the image forming apparatus 100 using this electrophotographic system, a photosensitive layer of a rotating photosensitive drum 101 is uniformly charged by using a charging roller 102 and then exposed by an exposure unit 103 such as a laser beam to electrostatic latent. An image is formed, and the electrostatic latent image is developed with toner to form a toner image. The toner image is transferred onto the recording paper 107. The recording paper 107 is composed of a fixing roller 10 and a pressure roller 112. The toner image is heat-fixed by passing through a roller-type heat fixing device 110.

  In such a heat fixing device of the image forming apparatus 100, an ethylene tetrafluoride resin (PTFE) coated on the outer peripheral surface of a thin cored bar made of a hollow cylindrical body of metal such as aluminum to prevent toner adhesion. A fixing roller 10 provided with a release layer made of a fluororesin such as tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin (PFA) or tetrafluoroethylene / hexafluoropropylene copolymer resin (FEP). Although being used, the heating and fixing roller 10 is provided with a heater such as a halogen lamp in the hollow portion of the thin metal core along the rotation center line, and the fixing roller 10 is heated from the inside by its radiant heat. In addition, by passing the recording paper 107 between the fixing roller 10 and the pressure roller 112, the toner adhering to the recording paper 107 is removed. And it is adapted to fix on the recording paper by pressurizing while softened by heat of the fixing roller 10 a.

  Here, the effect of the present invention was confirmed.

  For comparison, a roller according to the prior art (cylindrical material (element tube) having an inner diameter of 39.2 mm and an outer diameter of 41.6 mm (wall thickness 1.2 mm) is used, and a rib with a height of 0.5 mm is used inside And a fixing roller (model cross-sectional view is shown in FIG. 15), and the same cylindrical material as this roller according to the related art, except that the central rib is not provided among the nine ribs. Instead, a ring-shaped reinforcing member (made of the same material as the cylindrical material) having an outer diameter of 39.1 mm, an inner diameter of 33 mm, and a thickness of 2 mm is inserted into the position of the central rib. According to the present invention, two ribs (height 0.2 to 0.3 mm) are formed on both sides of the ring-shaped reinforcing member in contact with the ring-shaped reinforcing member by the method described in FIG. The fixing roller and the outer shape of the two fixing rollers and the rib forming portion are obtained. Wall thickness of is the same.

  As a result of evaluating these fixing rollers under the same conditions, the roller according to the related art caused crushing of 0.15 to 0.20 mm with respect to the equal pressure roller load applied to these rollers. The crushing by the roller according to No. was 0.04 mm or less.

  As described above, the fixing roller according to the present invention further improves the crushing strength of the conventional thin-walled fixing roller with ribs. If necessary, one or a plurality of ring-shaped reinforcing members can be used in actual use. Reinforcement without excess or deficiency according to the applied pressure is possible.

  As described above, the fixing roller according to the present invention can be strengthened more than the conventional technology in the thin fixing roller by the ring-shaped reinforcing member, and can be made thinner, that is, the heat capacity can be reduced, and the fixing device can be reduced. It is possible to shorten the start-up time when it is incorporated in the device, and it is possible to increase the pressurizing force, so that the image quality can be improved and the fixing property can be improved.

  The roller cored bar according to the present invention is small in deformation, so that the thickness can be extremely reduced and the heat capacity can be reduced. Therefore, the preheating time when incorporated in the fixing device as a fixing roller is extremely short, and the preheating is performed. The power consumption can be reduced, and the image fixing device having such a fixing device consumes less power due to preheating and can form an image without waiting time. Therefore, an electrophotographic copying machine, a laser printer, a facsimile machine can be used. Etc. are suitable.

It is a model sectional view showing roller mandrel A concerning the present invention. FIG. 5 is a model diagram (a diagram showing a state in which a ring-shaped reinforcing member B is inserted into a predetermined position of the cylindrical member 1) illustrating a method for producing the roller core A ′ according to the present invention. FIG. 3 is an enlarged model cross-sectional view of the vicinity of the ring-shaped reinforcing member B when the ring-shaped reinforcing member B is inserted into a predetermined position in the cylindrical member 1 by the reinforcing ring holder 2a. FIG. 5 is a model cross-sectional view showing a state in which a spinning roller 4 is pressed against an outer surface of a cylindrical material 1 as shown in FIG. 4 to form a rib. The It is model sectional drawing which shows the state which has cut the outer surface of the cylindrical material 1 in which the rib was formed. It is a model expanded sectional view near the rib of the cylindrical material 1 which formed the rib. The figure which shows the manufacturing method of the roller metal core which has two or more ring-shaped reinforcement members distribute | arranged in contact with these two ribs between two adjacent ribs (two ring-shaped reinforcement members B are shown). It is a figure which shows the state which inserted in the predetermined position of the cylindrical material 1, and formed the two ribs which contact | connect one ring-shaped reinforcement member B). The figure which shows the manufacturing method of the roller metal core which has two or more ring-shaped reinforcement members distribute | arranged in contact between these two ribs between two adjacent ribs (in two ring-shaped reinforcement members B) FIG. 2 is a diagram illustrating a state in which two ribs in contact with each other are formed. The figure which shows the manufacturing method of the roller metal core which has two or more ring-shaped reinforcement members distribute | arranged in contact with these two ribs between two adjacent ribs (3rd and 3rd ring shape) Is a diagram showing a state in which two ribs are formed in contact with one of the ring-shaped reinforcing members B). The figure which shows the manufacturing method of the roller metal core which has two or more ring-shaped reinforcement members distribute | arranged in contact with these two ribs between two adjacent ribs (in four ring-shaped reinforcement members B) FIG. 3 is a diagram illustrating a state where two ribs in contact with each other have been formed. The figure which shows the manufacturing method of the roller metal core which has two or more ring-shaped reinforcement members distribute | arranged between two adjacent ribs inside each other (cutting the surface of the cylindrical material 1) FIG. 3 is a view showing a state where the roller core metal A ″ according to the present invention is used. 1 is a model explanatory diagram of an image forming apparatus having a fixing device according to the present invention. It is model explanatory drawing which shows the fixing device which concerns on a prior art. It is a model explanatory drawing explaining the problem which arises with the fixing roller which concerns on a prior art. 2A is a cross-sectional view taken along a plane perpendicular to the axis of the fixing roller 201. FIG. 5B is a cross-sectional view in a plane including the axis of the fixing roller 201 and the axis of the pressure roller 202. FIG. It is a model sectional view showing a fixing roller according to the prior art.

Explanation of symbols

A, A ′ Roller core metal according to the present invention A ”Roller core metal intermediates A1 to A6, 1a Ribs provided in contact with a ring-shaped supply member B B Ring-shaped reinforcing member B1 C chamfered portion 1 Cylindrical material 1b Groove 2, 3 Jig 2a Reinforcing ring holder 2a1 Holding small diameter portion 2a2 Large diameter portion 2a3 Stepped wall portion 2a4 Reinforcing member holding leaf spring holding space 2a5 Holding leaf spring 2a51 Free end 2a52 Tip

Claims (7)

  In the hollow cylindrical roller cored bar, a plurality of ribs are provided on the inner surface of the roller cored bar, and at least one set of two ribs adjacent to each other is in contact with the two ribs. A roller cored bar having a ring-shaped reinforcing member.   2. The roller metal core according to claim 1, wherein chamfering is performed on both side surfaces of the inner side surface of the ring-shaped reinforcing member. A plurality of ribs are provided on the inner surface of the roller mandrel, and among these ribs, a ring-shaped reinforcing member is disposed between at least one pair of two adjacent ribs in contact with both of the two ribs. A hollow cylindrical roller core metal manufacturing method,
After inserting the ring-shaped reinforcing member into the thin-walled cylindrical structure so that the rotational symmetry axes thereof coincide with each other, the pressing member is pressed against the outer surface of the thin-walled cylindrical structure so as to contact the inner surface of the thin-walled cylindrical structure. A method for producing a roller core comprising the step of forming a rib in contact with the ring-shaped reinforcing member.   The method for manufacturing a roller cored bar according to claim 3, wherein both of the two ribs are formed after the ring-shaped reinforcing member is inserted.   A fixing roller having the roller cored bar according to claim 1.   A fixing device comprising the fixing roller according to claim 5.   An image forming apparatus comprising the fixing device according to claim 6.

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