JP6089714B2 - Fixing device, image forming apparatus - Google Patents

Description

The present invention is a fixing device using a reinforcing member, relates to an image forming equipment of an electrophotographic method using the fixing device.

There is a fixing device as one of the constituents of an electrophotographic image forming apparatus.
For example, a fixing belt, a pressure roller, a nip forming member that presses against the pressure roller via the fixing belt to form a nip portion, and is fixed to an inner diameter portion of the fixing belt. A reinforcing member that is supported from the opposite side, a substantially cylindrical support member that supports the rotation of the fixing belt from the inner peripheral side of the fixing belt, a heating means that heats the supporting member, and an axial end of the supporting member are held. The flange member fixed to the side plate of the fixing device and the flange member are separate from each other and have a higher temperature strength than the flange member, and the axial end of the reinforcing member with respect to the side plate of the fixing device There is known a fixing device including a reinforcing member supporting portion that supports the portion (see, for example, Patent Document 1).

In such a fixing device, in order to improve the fixing performance, the fixing belt contacts the pressure roller at a constant pressure along the longitudinal direction of the roller, and the fixing nip width (the fixing belt and the pressure roller contact each other). It is necessary to secure the width in the rotating direction.
Therefore, the above-described conventional fixing device uses a high-strength reinforcing member that supports the nip forming member from the back so that the nip forming member does not bend (does not warp) along the longitudinal direction. That is, the nip forming member that contacts the inner surface of the fixing belt on the fixed side is supported by the reinforcing member from the back surface. As a result, the pressure roller can be pressed against the fixing belt with a high load, and the fixing belt contacts the pressure roller with a constant pressure along the longitudinal direction of the roller.
As the above-described reinforcing member, a metal drawing material, a thick plate pressing material, or the like is mainly used.
Accordingly, the above-described conventional fixing device is suitable for obtaining stable nip characteristics at the nip portion.

  However, the reinforcing member used in the conventional fixing device (reference numeral 23 in Patent Document 1) has a predetermined thickness and strength in order to maintain a certain strength against bending and warping, and the length of the nip forming member. Since the surface accuracy of the portion in contact with the direction is required, a material such as a metal drawing material or a thick plate pressing material is cut out using a machine tool (in Patent Document 1, the receiving protrusion 23b is removed). It is formed with high surface accuracy). The machining process is much more laborious than other mass production methods such as pressing. Of course, this processing time increases the processing cost and the product price.

Further, in the cutting process, a large amount of chips are generated when a product is cut out from a material. This chip is recycled or treated as industrial waste.
In performing this recycling, a large amount of carbon dioxide is emitted, which is not preferable from the viewpoint of protecting the natural environment. Moreover, it is not preferable to treat as industrial waste from the viewpoint of protecting the natural environment.

The present invention, in the manufacturing process, processing time is reduced, a large amount of without discharging the chips, high strength in the same equivalent to the conventional reinforcing member, a fixing device using a high-precision reinforcing member, a fixing device and to provide an image forming equipment of electrophotographic system using a.

In order to solve the above problems, a fixing apparatus according to the present invention, the endless fixing belt, provided inside the fixing belt, and a heat source for heating the fixing belt, one of the inner circumferential surface of the fixing belt A fixing member provided so as to be in contact with the portion, and a plurality of rectangular metal plate-like members stacked and integrally joined together, and a reinforcing member that supports the fixing member from the inside of the fixing belt; via said fixing belt is rotatable in conjunction provided to press the fixing member, and a pressure rotating body passing together with the fixing belt transfer material carrying the unfixed toner, the reinforcing The member is formed by caulking and joining a plurality of the plate-like members, and the plate-like member is formed with a plurality of concave portions and convex portions for caulking the plate-like members, and the concave portion and the Depending on the convex part If part of the reinforcing member, than said support face of the fixing member, characterized in that it is located closer to the side opposite its supporting surface.

The present invention can provide the manufacturing process, processing time is reduced, without discharging a large amount of chips, high strength comparable to conventional reinforcing member, a fixing device using a high-precision reinforcing member In fact, it is possible to avoid or reduce the occurrence of deformation on the support surface to the fixing member by caulking .

1 is an explanatory diagram schematically illustrating a configuration of an image forming apparatus. FIG. 2 is an explanatory diagram schematically illustrating a configuration of a fixing device. It is explanatory drawing which shows the manufacturing method of the plate-shaped member which comprises a reinforcement member. It is a side view of the state which assembled | attached the reinforcement member and the fixing member. FIG. 6 is an explanatory view showing the periphery of a fixing nip. It is explanatory drawing which shows the joining method of plate-shaped members. It is explanatory drawing which shows the assembly process of a reinforcement member. It is explanatory drawing which shows the assembly | attachment relationship of a reinforcement member and a fixing member. It is sectional drawing which shows the assembly | attachment state of a reinforcement member and a fixing member. It is a top view of a reinforcing member. It is explanatory drawing which shows the assembly process of a reinforcement member and a reflection member. It is explanatory drawing which showed the structure of the image development apparatus typically. It is explanatory drawing which showed the structure of the plate-shaped joined body.

Embodiments of a fixing device using a reinforcing member, an electrophotographic image forming apparatus using the fixing device, and a method for manufacturing the reinforcing member will be described with reference to the drawings.
First, the configuration and operation of the entire image forming apparatus will be described with reference to FIG. FIG. 1 is an explanatory diagram schematically showing the configuration of the image forming apparatus.

As shown in FIG. 1, the image forming apparatus 1 is a tandem type color printer. Four bottles 102Y, 102M, 102C, and 102K corresponding to the respective colors (yellow, magenta, cyan, and black) are detachably installed in the bottle housing portion 101 above the image forming apparatus 1. Therefore, these four toner bottles 102Y, 102M, 102C, and 102K can be exchanged by a user or the like.
An intermediate transfer unit 85 is disposed below the bottle housing portion 101. Image forming units 4Y, 4M, 4C, and 4K corresponding to the respective colors (yellow, magenta, cyan, and black) are arranged in parallel so as to face the intermediate transfer belt 78 of the intermediate transfer unit 85.

  Each of the image forming units 4Y, 4M, 4C, and 4K is provided with photosensitive drums 5Y, 5M, 5C, and 5K as an example of an image carrier. Further, around each of the photosensitive drums 5Y, 5M, 5C, and 5K, a charging unit 75, a developing device 76, a cleaning unit 77, a neutralizing unit (not shown), and the like are disposed. Then, an image forming process (charging process, exposure process, developing process, transfer process, cleaning process) is performed on each photosensitive drum 5Y, 5M, 5C, and 5K, and each photosensitive drum 5Y, 5M, 5C, and 5K is performed. Thus, an image of each color is formed.

  The photosensitive drums 5Y, 5M, 5C, and 5K are rotationally driven in a clockwise direction in FIG. 1 by a drive motor (not shown). Then, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K are uniformly charged at the position of the charging unit 75 (charging process). Thereafter, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach the irradiation position of the laser light L emitted from the exposure unit 3, and an electrostatic latent image corresponding to each color is formed by exposure scanning at this position. (It is an exposure process).

  Thereafter, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing the developing device 76, and the electrostatic latent image is developed at this position to form toner images of each color (in the developing process). is there). Thereafter, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach positions facing the intermediate transfer belt 78 and the primary transfer bias rollers 79Y, 79M, 79C, and 79K, and at these positions, the photosensitive drums 5Y, 5M, and 5C. The toner image on 5K is transferred onto the intermediate transfer belt 78 (first transfer step). At this time, a small amount of untransferred toner remains on the photosensitive drums 5Y, 5M, 5C, and 5K.

Thereafter, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing the cleaning unit 77, and untransferred toner remaining on the photosensitive drums 5Y, 5M, 5C, and 5K at this position is removed from the cleaning unit 77. It is mechanically collected by a cleaning blade (this is a cleaning process).
Finally, the surfaces of the photosensitive drums 5Y, 5M, 5C, and 5K reach a position facing a neutralization unit (not shown), and the residual potential on the photosensitive drums 5Y, 5M, 5C, and 5K is removed at this position. Thus, a series of image forming processes performed on the photosensitive drums 5Y, 5M, 5C, and 5K is completed.

  Thereafter, the toner images of the respective colors formed on the respective photosensitive drums through the developing process are transferred onto the intermediate transfer belt 78 in an overlapping manner. In this way, a color image is formed on the intermediate transfer belt 78. Here, the intermediate transfer unit 85 includes an intermediate transfer belt 78, four primary transfer bias rollers 79Y, 79M, 79C, and 79K, a secondary transfer backup roller 82, a cleaning backup roller 83, a tension roller 84, and an intermediate transfer cleaning unit 80. , Etc. The intermediate transfer belt 78 is stretched around the three rollers 82 to 84 in a tensioned state, and is endlessly moved in the direction of the arrow in FIG. 1 by the rotational drive of the secondary transfer backup roller.

  The four primary transfer bias rollers 79Y, 79M, 79C, and 79K respectively sandwich the intermediate transfer belt 78 between the photosensitive drums 5Y, 5M, 5C, and 5K to form a primary transfer nip. Then, a transfer bias reverse to the polarity of the toner is applied to the primary transfer bias rollers 79Y, 79M, 79C, and 79K. The intermediate transfer belt 78 travels in the direction of the arrow and sequentially passes through the primary transfer nips of the primary transfer bias rollers 79Y, 79M, 79C, and 79K. In this way, the toner images of the respective colors on the photosensitive drums 5Y, 5M, 5C, and 5K are primarily transferred while being superimposed on the intermediate transfer belt 78.

  Thereafter, the intermediate transfer belt 78 onto which the toner images of the respective colors are transferred in an overlapping manner reaches a position facing the secondary transfer roller 89. At this position, the secondary transfer backup roller 82 sandwiches the intermediate transfer belt 78 between the secondary transfer roller 89 and forms a secondary transfer nip. The four color toner images formed on the intermediate transfer belt 78 are transferred onto the transfer material P conveyed to the position of the secondary transfer nip. At this time, untransferred toner that has not been transferred to the transfer material P remains on the intermediate transfer belt 78. Thereafter, the intermediate transfer belt 78 reaches the position of the intermediate transfer cleaning unit 80. At this position, the untransferred toner on the intermediate transfer belt 78 is collected. Thus, a series of transfer processes performed on the intermediate transfer belt 78 is completed.

  Here, the transfer material P conveyed to the position of the secondary transfer nip is fed from the paper feed unit 12 disposed below the image forming apparatus 1 to the paper feed roller 97 and the registration roller pair 98 (pressed against each other). A pair of rollers) or the like. Specifically, a plurality of transfer materials P such as transfer paper are stored in the paper supply unit 12 in a stacked manner. When the paper feed roller 97 is rotated counterclockwise in FIG. 1, the uppermost transfer material P is fed toward the rollers of the registration roller pair 98.

  The transfer material P transported to the registration roller pair 98 is temporarily stopped at a predetermined position by the registration roller pair 98 that has stopped rotating. Then, the registration roller pair 98 is rotationally driven in synchronization with the color image on the intermediate transfer belt 78, and the transfer material P is conveyed toward the secondary transfer nip. In this way, a desired color image is transferred onto the transfer material P.

  Thereafter, the transfer material P on which the color image is transferred at the position of the secondary transfer nip is conveyed to the position of the fixing device 20 described later. At this position, the color image transferred to the surface is fixed on the transfer material P by heat and pressure generated by the fixing belt 21 and the pressure roller 31 as an example of the rotating body. Thereafter, the transfer material P is discharged out of the apparatus through a pair of paper discharge rollers 99 (a pair of rollers pressed against each other). The transfer material P discharged from the apparatus by the discharge roller pair 99 is sequentially stacked on the stack unit 100 as an output image. Thus, a series of image forming processes in the image forming apparatus 1 is completed.

Next, the configuration and operation of the fixing device 20 will be described in detail with reference to FIG.
FIG. 2 is an explanatory diagram schematically showing the configuration of the fixing device 20.

  2, the fixing device 20 includes a fixing belt 21, a heat transfer member 22, a heater 25 as a heat source, a fixing member 26, a reinforcing member 23, a reflecting member 24, a pressure roller 31, a contact / separation mechanism 51, and the like. Consists of.

The fixing belt 21 is a thin endless belt having flexibility.
The fixing belt 21 has a base material layer, an elastic layer, and a release layer sequentially laminated from the inner peripheral surface side, and the total thickness is set to 1 mm or less. The base material layer of the fixing belt 21 has a layer thickness of 30 to 100 μm and is formed of a metal material such as nickel or stainless steel or a resin material such as polyimide.

  The elastic layer of the fixing belt 21 has a layer thickness of 100 to 300 μm and is formed of a rubber material such as silicone rubber, foamable silicone rubber, or fluororubber. By providing the elastic layer, minute irregularities on the surface of the fixing belt 21 in the fixing nip are not formed, and heat is uniformly transmitted to the toner image T on the transfer material P, thereby suppressing the occurrence of a cocoon skin image. The fixing nip is an area where the pressure roller 31 and the fixing belt 21 are in contact with each other.

  The release layer of the fixing belt 21 has a layer thickness of 10 to 50 μm, and includes PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), polyimide, polyetherimide, PES ( Polyether sulfide) and the like. By providing the release layer, releasability (peelability) for the toner T (toner image) is ensured. Further, the diameter of the fixing belt 21 is set to be 15 to 120 mm. In the present embodiment, the diameter of the fixing belt 21 is set to about 30 mm.

The heat transfer member 22 is a tubular member formed with an opening 22 a extending in the axial direction (the depth direction in FIG. 2), and is disposed inside the fixing belt 21.
The wall thickness of the heat transfer member 22 is 0.2 mm or less. By setting the wall thickness to 0.2 mm or less, the heating efficiency of the fixing belt 21 can be improved. As the material, a metal thermal conductor (a metal having thermal conductivity) such as aluminum, iron, and stainless steel can be used.

Further, the heat transfer member 22 is formed in a size close to or in contact with the inner peripheral surface of the fixing belt 21 described later at a position excluding the fixing nip portion.
As a result, the area in which the heat transfer member 22 and the fixing belt 21 are brought into sliding contact with each other is increased, and a problem that the wear of the fixing belt 21 is accelerated is suppressed. It is possible to suppress a problem that the heating efficiency is reduced.

Further, since the heat transfer member 22 maintains the circular posture of the flexible fixing belt 21, it is possible to reduce deterioration / breakage due to deformation of the fixing belt 21.
Further, in order to reduce the sliding resistance between the heat transfer member 22 and the fixing belt 21, the sliding contact surface of the heat transfer member 22 is formed of a material having a low friction coefficient, or fluorine is applied to the inner peripheral surface of the fixing belt 21. It is also possible to form a surface layer made of the containing material.

In the present embodiment, the heat transfer member 22 is formed to have a substantially circular cross section, but the heat transfer member 22 may be formed to have a polygonal cross section.
Further, in the case where a means for uniformly transferring heat from the heater 25 to the belt member and ensuring the running stability of the belt member during driving is prepared separately, the heat transfer member 22 is not provided. It is also possible to configure a fixing device that directly heats the belt. In that case, since the heat capacity of the heat transfer member 22 is excluded from the heat capacity of the entire fixing device, there is an advantage that it is possible to configure a fixing device with more excellent temperature rise performance and energy saving performance.

The heater 25 as a heat source is composed of a halogen heater, a carbon heater, or the like, and is provided inside the heat transfer member 22.
The heater 25 heats the heat transfer member 22 with radiant heat (radiant light) by infrared irradiation, and heats the fixing belt 21 via the heat transfer member 22. In other words, the heat transfer member 22 is directly heated by the heater 25, and the fixing belt 21 is indirectly heated by the heater 25 through the heat transfer member 22. The output control of the heater 25 is performed based on the detection result of the belt surface temperature by the temperature sensor 40 facing the surface of the fixing belt 21.

  Further, the temperature of the fixing belt 21 (fixing temperature) can be set to a desired temperature by such output control of the heater 25. As described above, in the fixing device 20, not only a part of the fixing belt 21 is locally heated, but the fixing belt 21 is almost entirely heated in the circumferential direction by the heat transfer member 22. In addition, even when the speed of the apparatus is increased, the fixing belt 21 is sufficiently heated, and the occurrence of fixing failure can be suppressed.

The fixing member 26 is provided so as to be in contact with a part of the inner peripheral surface of the fixing belt 21 and to close the opening 22a. In addition, the fixing member 26 has the same arrangement relationship as the arrangement of the joint portion 23e (consisting of the convex portion 23c and the concave portion 23d) in the reinforcing member 23 described later, and a fitting portion 26a that holds the reinforcing member 23 in between. Is provided.
The fixing member 26 is configured to be elastically deformable. As a material, a heat-resistant resin material such as a liquid crystal polymer or a metal such as aluminum can be used.

  By providing an elastic member such as silicone rubber or fluororubber between the fixing member 26 and the fixing belt 21, the belt surface follows minute irregularities on the surface of the transfer material P at the fixing nip, and the transfer target is transferred. Heat is uniformly transmitted to the toner image T on the material P, which is effective in preventing a cocoon skin image (a rough image).

  The reinforcing member 23 is a plate-like joined body in which a plurality of rectangular plate-like members 23 a are overlapped and integrally joined. The reinforcing member 23 is disposed so as to support the fixing member 22 from the inside of the fixing belt 21. As shown in FIG. 2, the plate-like member 23 a has an end portion 23 g (opposing portion) on the support portion side that supports the fixing member 22 formed in a single-blade shape. Of the plurality of plate-like members (FIG. 2 shows two plate-like members 23a), the two outermost ones are arranged such that the inclined surface 23h formed on the end 23g is on the inside. Yes.

Both ends of the reinforcing member 23 in the width direction are fixedly supported by side plates (not shown) of the fixing device 20. In the present embodiment, the two plate-like members 23a having the same shape and the same material are integrally joined to constitute the reinforcing member 23. However, as will be described later, the plate-like member 23a has two members. It is not limited to a sheet.
In addition, by superimposing and integrally joining the plurality of plate-like members 23a, it is possible to obtain a high-strength and high-precision reinforcing member equivalent to the conventional reinforcing member.

Both ends of the reinforcing member 23 in the width direction are fixedly supported by side plates (not shown) of the fixing device 20. The reinforcing member 23 abuts against the pressure roller 31 via the fixing member 26 and the fixing belt 21, thereby preventing a problem that the fixing member 26 is greatly deformed by the pressure applied by the pressure roller 31 in the fixing nip. ing. In order to satisfy the above-described function, the reinforcing member 23 is preferably formed of a metal material having high mechanical strength such as stainless steel or iron alloy.
Details of the reinforcing member 23 will be described later.

The reflecting member 24 has a substantially rectangular shape with a cross section opened on one side, so that a part of the reflecting member 24 wraps around the reinforcing member 23 (the reflecting member 24 passes the reinforcing member 23). It is supported (attached) only to the reinforcing member 23. The reflection member 24 reflects infrared rays over the entire range of the reinforcing member 23 that receives infrared irradiation from the heater 25. Thus, the heater 25 or these heat, since it is difficult deprived large reinforcing member 23 of the heat capacity, faster Atsushi Nobori, which is advantageous for energy saving (it is not necessary to warm the unnecessary place).

Further, since the reflecting member 24 is supported by the reinforcing member 23 and does not require a fixing member such as a screw, the reflecting member 24 is easily assembled and inexpensive. On the other hand, a part of the reflecting member 24 wraps around the surface opposite to the surface on which the heater 25 is disposed. Thereby, since the reflecting member 24 can be held by being hooked on the reinforcing member 23, it is not necessary to perform secondary processing on the reinforcing member 23, and it can be configured at low cost.

  In addition, when the heater 25 is a heat source that uses radiant heat such as a halogen heater, a heat insulating member is provided on the surface 24a of the reflecting member 24 facing the heater 25, or a BA treatment (bright annealed finish). Or mirror polishing treatment. Since the radiant heat (heat for heating the reinforcing member 23) from the heater 25 toward the reinforcing member 23 is insulated or reflected and used for heating the heat transfer member 22, the fixing belt 21 (heat transfer member 22) is heated. Efficiency will be further improved.

  The pressure roller 31 is provided so as to be pressed against the fixing member 26 via the fixing belt 21 and is configured to be rotatable so as to pass the transfer material P on which unfixed toner is placed together with the fixing belt 21.

  The pressure roller 31 that abuts the outer peripheral surface of the fixing belt 21 at the fixing nip has a diameter of about 30 to 40 mm and has an elastic layer 33 formed on a hollow cored bar 32. The elastic layer 33 of the pressure roller 31 is made of a material such as foamable silicone rubber, silicone rubber, or fluorine rubber. A thin release layer made of PFA, PTFE or the like can be provided on the surface layer of the elastic layer 33. The pressure roller 31 is pressed against the fixing member 26 via the fixing belt 21 to form a desired fixing nip between the pressure roller 31 and the fixing belt 21.

The pressure roller 31 is provided with a gear that meshes with a drive gear of a drive mechanism (not shown), and the pressure roller 31 is rotationally driven in the direction of arrow R (clockwise direction) in FIG. The pressure roller 31 is rotatably supported at both ends in the width direction on a side plate (not shown) of the fixing device 20 via a bearing 34.
A heat source such as a halogen heater can be provided inside the pressure roller 31.

  Further, when the elastic layer 33 of the pressure roller 31 is formed of a sponge-like material such as foamable silicone rubber, the pressure applied to the fixing nip can be reduced, so that the flexure generated in the fixing member 26 is reduced. Can be reduced.

  Furthermore, since the heat insulation of the pressure roller 31 is enhanced and the heat of the fixing belt 21 is difficult to move to the pressure roller 31 side, the heating efficiency of the fixing belt 21 is improved. In FIG. 2, the diameter of the fixing belt 21 is formed to be equal to the diameter of the pressure roller 31, but the diameter of the fixing belt 21 may be formed to be smaller than the diameter of the pressure roller 31. it can.

In that case, since the curvature of the fixing belt 21 in the fixing nip is smaller than the curvature of the pressure roller 31, the transfer material P sent from the fixing nip is easily separated from the fixing belt 21.
In addition, the diameter of the fixing belt 21 can be formed to be larger than the diameter of the pressure roller 31, but the pressure roller 31 is independent of the relationship between the diameter of the fixing belt 21 and the diameter of the pressure roller 31. The applied pressure is not applied to the heat transfer member 22.

  The contact / separation mechanism 51 contacts and separates the pressure roller 31 from the fixing belt 21. The pressure lever 51b is rotatably supported on a side plate (not shown) of the fixing device 20 around a support shaft 51a provided on one end side. The central portion of the pressure lever 51b is in contact with a bearing 34 of the pressure roller 31 (movably held in a long hole formed in the side plate).

  A pressing member such as a pressure spring (not shown) is connected to the other end of the pressure lever 51b. With such a configuration, the pressure lever 51b rotates about the support shaft 51a, and during a normal fixing operation, the pressure roller 31 presses the fixing belt 21 to form a desired fixing nip. On the other hand, when the jam is being dealt with, and other than during the normal fixing operation, the pressure roller 31 is detached from the fixing belt 21 (or the fixing belt 21 is depressurized) by an unillustrated eccentric cam lever or the like.

  Hereinafter, the normal operation of the fixing device 20 configured as described above will be briefly described. When the power switch of the image forming apparatus 1 is turned on, electric power is supplied to the heater 25 and rotation driving of the pressure roller 31 in the arrow R direction is started. As a result, the fixing belt 21 is driven and rotated by the frictional force with the pressure roller 31.

  Thereafter, the transfer material P is sent from the paper supply unit 12, and an unfixed color image is transferred onto the transfer material P at the position of the secondary transfer roller 89. The transfer material P on which an unfixed toner image is placed is conveyed in the direction of the arrow Y10 in FIG. 2 while being guided by a guide plate (not shown), and reaches the fixing nip of the fixing belt 21 and the pressure roller 31 that are in pressure contact. Sent in.

Then, the surface of the transfer material P is heated by the fixing belt 21 heated by the heat transfer member 22 (heater 25) and the pressing force of the fixing member 26 reinforced by the reinforcing member 23 and the pressure roller 31. The toner image is fixed.
Thereafter, the transfer material P delivered from the fixing nip is conveyed in the direction of arrow Y11.

Next, the reinforcing member 23 according to the present embodiment will be described in detail with reference to FIGS.
FIG. 3 is an explanatory view showing a method for manufacturing the plate-like member 23 a constituting the reinforcing member 23.

As shown in FIG. 3, when the plate-shaped material is fixed on the die and the punch is lowered, the punch comes into contact with the material. When the punch is further lowered, the material is pushed by the punch blade edge and the die blade edge. Deform (a).
When the punch is further lowered from there, a crack that connects the corner of the punch edge and the corner of the die edge occurs in the material (b).
The part of the material in contact with the blade surface of the punch and the blade surface of the die becomes a shear surface, and the cracked portion becomes a fracture surface and is punched (c). The side of the shearing surface and the fracture surface is the above-mentioned single-edged end portion 23g, the fracture surface is the inclined surface 23h described above, and the shear surface is the end surface 23k (FIG. 4).

Also, before, after, or simultaneously with the die cutting, the plurality of convex portions 23c and the plurality of concave portions 23d having the same diameter as the outer diameter of the convex portions 23c (see FIGS. 6, 7, and 9) ) Is press-molded or extruded. Note that the recess 23d may be a through hole or a half punched hole (a hole having a bottom). Details of the positional relationship between the convex portion 23c and the concave portion 23d will be described later.
In this manner, a rectangular plate-like member 23a having a single-blade end portion 23g, a plurality of convex portions 23c, and a plurality of concave portions 23d is manufactured (pressing process).

That is, the pressing process according to the present embodiment includes rectangular die cutting from a material, half punching with a punch, and punching with a punch.
In this way, the plate-like member 23a constituting the reinforcing member 23 is manufactured by pressing, so that the labor of processing is reduced and a large amount of chips are discharged as compared with the conventional manufacturing method by cutting. There is nothing to do.

FIG. 4 is a side view of the state in which the reinforcing member 23 and the fixing member 26 are assembled.
FIG. 4A shows an example in which the reinforcing member 23 is configured by stacking two plate-like members 23a manufactured by the method shown in FIG.

  On the front and back of the two plate-like members 23a, the surface in contact with the shear surface (the surface on the side where the punch blade edge and the die blade edge enter during processing) is the outside, and the surface in contact with the fracture surface (the punch edge during processing) The two plate-like members 23a are integrally joined with the die surface of the die from which the blade edge comes off facing inward. In other words, the two plate-like members 23a are integrally joined with the inclined surface 23h formed at the end 23g of the plate-like member 23a facing inward.

  By adopting such a configuration, the reinforcing member 23 will support two places (x and y) separated from each other on the upper and lower sides of the fixing member 26, and the fixing member 26 is prevented from falling to the upper side or the lower side. A stable nip width can be obtained.

  FIG. 4B shows an example in which the three plate-like members 23a are stacked to form the reinforcing member 23. However, the two plate-like members 23a located on the outside are not similar to the above-described example. It is arranged with the cross-sectional side facing outward. In this example, the reinforcing member 23 supports two points (x and y) upstream and downstream of the fixing member 26 and a point (z) therebetween. The fixing member 26 can be more stably held by increasing the number of support points.

As described above, the number of the plate-like members 23a is not limited to two or three, and can be appropriately selected according to processing conditions and use conditions. However, of the plurality of plate-like members 23a, two of the outermost plates are arranged with the surface of the side where the punch blade edge and the die blade edge are placed facing outward during press working. In other words, of the plurality of plate-like members 23a, the two outermost ones are arranged such that the inclined surface 23h formed on the end 23g is on the inner side.
As described above, the reinforcing member 23 can obtain a reinforcing member with high strength and high accuracy equivalent to that of a conventional reinforcing member by stacking and integrally joining a plurality of plate-like members 23a.

FIG. 5 is an explanatory view showing the periphery of the fixing nip.
As shown in FIG. 4A, when the two plate-like members 23a are overlapped and formed, when the load from the pressure roller 31 is received, the fixing member 26 has two support portions x of the plate-like member 23a. , Y and is slightly bent in the gap formed by the fracture surface of the middle part, resulting in a shape as shown by a solid line. In addition, a dashed-two dotted line shows the state before bending.

  As the fixing member 26 is deformed in this manner, the fixing member 26 has a shape that conforms to the cylindrical outer shape of the pressure roller 31, which is more advantageous in securing a wide nip width.

  Further, the transfer material P has a nip shape wound around the pressure roller 31, and the behavior of the transfer material P after the fixing process is easily directed to the non-image surface side as indicated by the solid line. There is also an effect of suppressing a problem that the material P sticks to the fixing belt 21 and is jammed in the fixing device.

  In the same figure, the front end side of the plate-like member 23a is processed to be thinner (t ') than the original material plate thickness t at the time of pressing. In other words, the end of the reinforcing member 23 on the support portion side is crushed in accordance with the fitting tolerance with the fitting portion 26a. By doing so, as will be described later with reference to FIG. 9, the thickness dimension of the reinforcing member 23 can be accurately obtained at the place where the reinforcing member 23 and the fixing member 26 are fitted, so that the fitting tolerance relationship is established. It becomes easy to control.

FIG. 6 is an explanatory view showing a method of joining the plate-like members 23a.
The protrusion 23c and the recess 23d described above have a dimensional tolerance relationship such that an interference fit is achieved, and a plurality of plate-like members 23a are overlapped with each other, and the protrusion 23c is press-fitted into the recess 23d to be caulked and joined. As a specific method of caulking, when the concave portion 23d is a through hole, after inserting the convex portion 23c into the concave portion 23d, the tip side of the convex portion 23c is crushed with a jig, and extrusion molding is performed. For example, there is a method (joining step) in which the convex portion 23c is applied to the concave portion 23d, and is pressed by a jig from the back side of the convex portion 23c (press-fit joining).
As described above, the reinforcing member 23 according to the present embodiment joins the plurality of plate-like members 23a together by caulking with the convex portions 23c and the concave portions 23d, and without using any other special joining members. In addition, the plate-like members 23a can be firmly joined to each other.
In this manner, the convex portions and the concave portions are fitted and the plate-like members 23a are joined to each other. However, if the required strength is ensured, all the convex portions and the concave portions may not be fitted.

FIG. 7 is an explanatory diagram showing an assembly process of the reinforcing member 23.
Each plate-like member 23a of the two plate-like members 23a shown in FIG. 7A has the same number of recesses 23d and protrusions 23c for caulking the plate-like members 23a alternately (three each). ) So as to be symmetrically formed (becomes wider from the center toward the outside).

When the two plate-like members 23a described above are prepared and the lower plate-like member 23a is rotated 180 degrees so that the front and back are reversed with the center (reference position) in the longitudinal direction as the rotation center (one plate-like) With respect to the member 23a, the other plate-like member 23a is turned over in the longitudinal direction of the plate-like member 23a), and the posture is as shown in FIG. That is, the convex portion 23c of the upper plate-like member 23a has a corresponding positional relationship with the concave portion 23d of the lower plate-like member 23a, and the upper concave portion 23d has a corresponding positional relationship with the concave portion 23c of the lower plate-like member 23a. Ai relationship. And as shown in FIG.7 (c), both the plate-shaped members 23a are caulked and joined (joining process).
The convex part 23c is caulked and joined to the concave part 23d to constitute the joint part 23e. The joining portion 23e includes a first joining portion constituted by a convex portion 23c of one (for example, the upper) plate-like member 23a and a concave portion 23d of the other (for example, the lower) plate-like member 23a, It consists of a concave portion 23d of the plate-like member 23a (for example, the upper side) and a second joint portion constituted by the convex portion 23c of the other (for example, the lower) plate-like member 23a.

  Thus, in the state of the single plate-like member 23a, the position where the convex part 23c and the concave part 23d are fitted to each other by rotating 180 degrees so that the front and back are reversed with the center (reference position) in the longitudinal direction as the center of rotation. If it arrange | positions in relationship, since the metal mold | die for shape | molding the plate-shaped member 23a will be sufficient, it can manufacture at low cost.

  Further, even if the plate-like member 23a expands due to heating, if the material and shape of the upper and lower members to be overlapped are the same, the amount of thermal expansion in each place is the same, so distortion does not occur, and the component accuracy of the entire reinforcing member 23 Can be maintained even in a hot state.

  Furthermore, since the left and right are symmetrical when integrally joined, there is an advantage that a dimensional left-right deviation hardly occurs in the reinforcing member 23. In addition, since the arrangement intervals of the plurality of joint portions 23e are the same on the left and right with respect to the center (reference position) in the longitudinal direction of the reinforcing member 23, there is also a left / right deviation in the deflection when being loaded by the pressure roller 31. Hard to occur.

  Further, the reinforcing member 23 has the same length of the end face 23k (shear surface) in order to overlap the plate-like members 23a having the same shape.

  At the time of press molding, distortion due to shearing occurs, and warping occurs in the case of a single part, but the warping is offset because two parts having the same shape and the same tendency are joined. Therefore, there is an effect that does not adversely affect the fixing property and the paper conveyance property. The plate-like member 23a is illustrated as an example in which three convex portions 23c and three concave portions 23d are formed. However, the number and shape of the concave portions 23d and the convex portions 23c are not limited to the above, and are necessary. It is desirable to change arbitrarily according to it.

FIG. 8 is an explanatory diagram showing the assembly relationship between the reinforcing member 23 and the fixing member 26.
The arrangement of the joint portions 23e in the longitudinal direction of the reinforcing member 23 is configured such that the distance between the adjacent portions increases from the center of the reinforcing member 23 toward the end portion (L1 <L2 <L3). That is, the joint part 23e formed by the convex part 23c and the concave part 23d is adjacent to the joint part 23e toward the longitudinal direction end of the plate-like member 23a with the center (reference position) in the longitudinal direction of the reinforcing member 23 as a boundary. It arrange | positions so that the space | interval of 23e may open. Further, the fitting portions 26a of the fixing member 26 are also arranged at the same interval as the joint portion 23e.

  When the load from the pressure roller 31 is received, the reinforcing member 23 bends in the load direction, and the displacement at the center is larger than the end in the longitudinal direction. By concentrating the portions near the center, it is possible to increase the strength as the reinforcing member 23 even in the same shape.

  Further, the joint portion 23e is disposed close to the end surface side opposite to the support surface to the fixing member 26 (end surface on the support side of the reinforcing member 23). That is, as shown in FIG. 8, the joining portion 23e has a distance W2 from the support surface to the fixing member 26 to the center position of the joining portion 23e, and the end surface on the opposite side of the support surface to the center position of the joining portion 23e. The distance W1 is arranged at a position where W1 <W2. Thereby, it can be expected to avoid or reduce the deformation of the support surface to the fixing member 26 due to the joining (caulking).

  When the pressure is applied, the end of the reinforcing member 23 on the support portion side and the fixing member 26 are continuously in contact with each other over a region corresponding to the entire region through which the transfer material passes. In the longitudinal direction of the reinforcing member 23 (in the depth direction in FIG. 2), contact is made continuously and not intermittently, so that no local pressure loss occurs in the fixing nip, and uniform throughout the sheet passing area. The toner can be dissolved in the toner, and unevenness in image quality can be prevented.

  The reinforcing member 23 and the fixing member 26 have an end portion (fitting tolerance with the fitting portion 26a) of the reinforcing member 23 so that the fitting portion 26a and the joint portion 23e face each other. And the fitting portion 26a are fitted together and joined. The reason for this will be described with reference to FIG.

FIG. 9 is a cross-sectional view showing an assembled state of the reinforcing member 23 and the fixing member 26.
As shown in FIG. 9, the reinforcing member 23 is microscopically undulated over the entire region in the axial direction by joining the plate-like members 23a. There is no gap g between the joint portions 23e because there is nothing to bring the plate-like members 23a into close contact with each other. By disposing the fitting portion 26a of the fixing member 26 in a portion where there is no gap in the joint portion 23e, it is easy to control the dimensional tolerance (fitting) between them.

FIG. 10 is a plan view of the reinforcing member 23.
The end portion 23f on the support portion side of the reinforcing member 23 is non-linear in the longitudinal direction, and has a convex curve shape with the center protruding from both ends in the longitudinal direction. As described above, the tip shape is not a straight line but a curved line, so that the nip width and surface pressure distribution in the longitudinal direction can be adjusted by the shape of the reinforcing member 23. In general, if the central portion is protruded from the end portion, the amount of bending of the fixing member 26 and the reinforcing member 23 due to the load is compensated, and the distribution of the nip width and the surface pressure in the longitudinal direction can be made uniform. This is advantageous with respect to the sheet transportability.

FIG. 11 is an explanatory view showing an assembly process of the reinforcing member 23 and the reflecting member 24.
In FIG. 11A, the reinforcing member 23 and the reflecting member 24 are in a state before assembly and are separated from each other. From this state, the reinforcing member 23 is moved in the direction of the arrow and inserted into the opening of the reflecting member 24.

  FIG. 11B is a diagram in the middle of incorporating the reflecting member 24 into the reinforcing member 23. While the fixing portion 24b of the reflecting member 24 is elastically deformed and bent as the reinforcing member 23 is inserted at the longitudinal end portion of the reflecting member 24, the reinforcing member 23 still proceeds in the arrow direction.

  In FIG. 11C, the reinforcing member 23 further advances from the state of FIG. 11B in the direction of the arrow shown in FIG. 11A, and the fixing portion 24b of the reflecting member 24 completely gets over the reinforcing member 23, and the fixing portion 24b. By restoring the original shape by its own elastic force, the fixing portion 24b is hooked on the reinforcing member 23 and the assembly is completed. In this state, the reinforcing member 23 does not come off the reflecting member 24 unless the fixing portion 24b is intentionally deformed by an external force.

  According to such an assembling method, since it is possible to assemble using the elastic deformation of the component itself, there is no need to separately provide a fixing member 26 such as a screw, and a machining process such as a pilot hole machining or a tapping machining of the screw. The cost of parts does not increase due to the increase in In addition, it is not necessary to consider the installation space such as the screw head and the screw tip, the degree of freedom of layout is increased in a narrow space inside the fixing belt 21, and a separate tool is not required at the time of assembly, and it can be assembled with bare hands. Therefore, the assembling property becomes good.

  As described above, the reflecting member 24 has a substantially rectangular cross section with one side opened, and a part of the reflecting member 24 wraps around the reinforcing member 23 (the reflecting member 24 is The reinforcing member 23 is configured to be gripped). By setting it as such a cross-sectional shape, even if the reinforcement member 23 is a simple shape which can be created only by punching a flat plate, the reflection member 24 can be held. In the present embodiment, for the purpose of reducing the material cost and processing cost of the parts, the reinforcing member 23 is formed on the surface so that the material is not easily oxidized even in a high temperature environment by punching a steel material by pressing. It consists of plating treatment.

As described above, the fixing device according to this embodiment, in the manufacturing process, processing time is reduced, without discharging a large amount of chips, high strength in the same equivalent to the conventional reinforcing member, precision Since it is possible to provide a fixing device using a reinforcing member, it is possible to avoid or reduce the occurrence of deformation on the support surface to the fixing member by caulking . Further, Ru can provide an electrophotographic image forming apparatus using the fixing device.

Further, as described above, the reinforcing member 23 according to the present embodiment is a plate-like joined body in which a plurality of rectangular plate-like members 23a are overlapped and integrally joined. The use of the plate-like joined body is not limited to the reinforcing member of the fixing device.
For example, the developer regulating member, which is a constituent member of the above-described developing device, may be configured by a plate-like joined body.
That is, as shown in FIG. 12, the developing device 76 according to the present embodiment uses a two-component developer that is disposed facing and carries a photosensitive drum 79 as an image carrier that carries an electrostatic latent image. A developer carrying member 761 for developing the electrostatic latent image on the photosensitive drum 79 and a plate that is disposed opposite to the developer carrying member 761 with a predetermined gap and regulates the two-component developer on the developer carrying member 761. And a developer regulating member 764.
Further, the developer carrier 771 has a magnet carrier 762 provided with a magnet for attracting the two-component developer, and a cylindrical shape containing the magnet carrier 762, and the developer carrier 771 is attracted to the surface by the magnet carrier. A developer sleeve 763 for carrying a two-component developer, and the developer regulating member 764 is configured by the plate-like assembly described above.

Here, the features of the plate-like assembly according to the above-described embodiment will be listed.
(1) An opposing portion facing the outer peripheral surface of the rotating body is provided so that the longitudinal direction extends along the axial direction of the rotating body, and an upstream end surface of the facing portion in the rotational direction of the rotating body; A plate-like assembly configured such that a surface connecting end faces on the downstream side is a plane,
A plurality of plate-like members each having an inclined surface that tapers from the other end portion away from the outer peripheral surface of the rotating body toward the facing portion with respect to the facing portion. When superposed in the direction along the outer peripheral surface, the inclined surfaces of the two outermost plate-like members are superposed so as to face each other and are integrally joined. (FIG. 13).

(2) In the above (1), the inclined surface of the plate-like member is a blade surface in which the side of the facing portion is formed in a single-blade shape.

(3) In said (1) or (2), the said some plate-shaped member is comprised with the same shape and the same material, It is characterized by the above-mentioned.

(4) In any one of (1) to (3), a plurality of the plate-like members are caulked and joined by press-fitting.

(5) In the above (4), the plurality of plate-like members have a convex portion and a concave portion in a plane facing the adjacent plate-like member when superimposed in a direction along the outer peripheral surface of the rotating body. Prepared,
A first joint portion in which the convex portion provided in one of the plate-like members adjacent when overlapped in the direction along the outer peripheral surface of the rotating body is inserted into the concave portion provided in the other plate-like member; and The convex part provided in the other plate-like member is formed by caulking or press-fitting at least the second joint part inserted into the concave part provided in the one plate-like member. To do.

(6) In said (5), the said convex part and the said recessed part are predetermined intervals toward the one side and the other side along the said longitudinal direction from this reference position by making the predetermined position of the said plate-shaped member into a reference position. Formed with
The concave portion is disposed at a position that is away from the reference position toward the other side by a distance corresponding to the distance from the reference position to the convex portion that is formed toward the one side. The convex portion is arranged at a position away from the reference position toward the other side with a distance corresponding to the distance to the concave portion formed toward the one side.

(7) In the above (6), the other side of the other plate-like member is opposed to the one side of one of the two plate-like members located on the outermost side. It is characterized by being superimposed on.

(8) In any one of (5) to (7), at least one of the first joint portion and the second joint portion is the same as the opposite portion and the other end portion in a direction orthogonal to the longitudinal direction. It is arranged on the other end side with reference to a line segment connecting distance points.

(9) In any one of (5) to (8), the first joint portion and the second joint portion are adjacent to each other from the reference position of the plate member toward the one side and the other side. The first joint portions to be arranged, the adjacent second joint portions to each other, and the gap between the adjacent first joint portions and the second joint portions are arranged to be large.

(10) In any one of the above (1) to (9), the facing surface where the facing portion of the plate-shaped member faces the outer peripheral surface of the rotating body is located at a position facing the central portion of the rotating body. It is characterized by a convex curved shape protruding in the direction of the rotating body.

(11) In any one of the above (1) to (10), the surface of the plate-like joined body is plated.

(12) The fixing device according to the present embodiment has the following characteristics.
The fixing device according to the present embodiment is provided so as to contact an endless fixing belt, a heat source for heating the fixing belt, and a part of an inner peripheral surface of the fixing belt. A fixing member, a reinforcing member that supports the fixing member from the inside of the fixing belt, a pressing member that is pressed against the fixing member via the fixing belt, and is configured to be rotatable so that unfixed toner is placed thereon. And a pressure roller for passing the transfer material together with the fixing belt, wherein the reinforcing member is formed of the plate-like joined body according to any one of (1) to (11). And

(13) The developing device according to the present embodiment has the following characteristics.
The developing device according to the present embodiment is disposed to face an image carrier that carries an electrostatic latent image, and develops the electrostatic latent image on the image carrier using a two-component developer that is carried. A developing device comprising: a developer carrying member; and a plate-like developer regulating member disposed opposite to the developer carrying member with a predetermined gap and regulating a two-component developer on the developer carrying member, The developer carrier has a magnet carrier having a magnet for attracting the two-component developer, and a cylindrical shape including the magnet carrier, and the two-component developer is formed on the surface by the magnet carrier. And the developer regulating member is composed of the plate-like joined body according to any one of (1) to (11).

20 fixing device 21 fixing belt 22 heat transfer member 23 reinforcing member 23a plate-like member 23f end portion 23g on the supporting portion side of the reinforcing member end portion 24 on the supporting portion side of the plate-like member reflecting member 25 heater (heat source)
26 Fixing member 31 Pressure roller P Transfer material

JP 2012-128331 A

Claims (14)

An endless fixing belt,
Provided inside the fixing belt, and a heat source for heating the fixing belt,
A fixing member provided in contact with a part of the inner peripheral surface of the fixing belt;
A plurality of rectangular metal plate-like members are overlapped and integrally joined, and a reinforcing member that supports the fixing member from the inside of the fixing belt;
A pressure rotator which is provided so as to be pressed against the fixing member via the fixing belt and is configured to be rotatable, and which passes a transfer material on which unfixed toner is placed together with the fixing belt ;
Equipped with a,
The reinforcing member is formed by caulking and joining a plurality of the plate-shaped members,
The plate-like member is formed with a plurality of concave and convex portions for caulking the plate-like members,
The joint portion formed by the concave portion and the convex portion is arranged at a position closer to the surface of the reinforcing member opposite to the supporting surface than the supporting surface to the fixing member. . The plate-like member is formed in a single-edged shape at the end on the support side that supports the fixing member,
2. The fixing device according to claim 1, wherein two of the plurality of plate-like members positioned on the outermost side are disposed such that an inclined surface formed at the end portion is on an inner side. .   The fixing device according to claim 2, wherein the reinforcing member includes two plate-like members.   The fixing device according to claim 1, wherein the plurality of plate-like members are configured with the same shape and the same material. The concave portion and the convex portion are arranged symmetrically with respect to the center in the longitudinal direction of the plate member,
The reinforcing member is caulked and joined to one plate-like member by turning the other plate-like member upside down in the longitudinal direction of the plate-like member. The fixing device according to claim 1. The said joint part is arrange | positioned so that the space | interval of the said adjacent joint part may open, so that it goes to the end of the longitudinal direction of the said plate-shaped member from the center of the longitudinal direction of the said reinforcement member. Item 6. The fixing device according to any one of Items 1 to 5. The fixing member has the same arrangement relationship as the arrangement of the concave portion and the convex portion, and is provided with a fitting portion that sandwiches and holds the reinforcing member,
Claim 1, said fitting portion and the joint portion so as to face, and said reinforcing member and said fitting portion and the end portion of the support part side to the fixing member are each other fit or fixing device according to any one of 6. The fixing device according to claim 7 , wherein an end portion of the reinforcing member on the support portion side is crushed in accordance with a fitting tolerance with the fitting portion . The end of the supporting portion side of the reinforcing member and said stationary member, said of claims 1 to 8, this and features are over the region corresponding to the entire area where the transfer material passes continuously in touch The fixing device according to claim 1. The fixing member is configured to be elastically deformable,
The end of the supporting portion side of the reinforcing member, a fixing device according to any one of claims 1 to 9, characterized in that in the longitudinal direction is non-linear. The fixing device according to claim 10, wherein an end portion of the reinforcing member on a support portion side has a convex curved shape with a center protruding from both ends in the longitudinal direction . The fixing device according to claim 1 , wherein a surface of the reinforcing member is plated . An endless fixing belt,
A heat source provided inside the fixing belt for heating the fixing belt;
A fixing member provided in contact with a part of the inner peripheral surface of the fixing belt;
A plurality of rectangular plate-like members are stacked and integrally joined, and a reinforcing member that supports the fixing member from the inside of the fixing belt;
A pressure rotator that is provided so as to be pressed against the fixing member via the fixing belt and is configured to be rotatable, and passes a transfer material on which unfixed toner is placed together with the fixing belt,
The reinforcing member has a reflecting member that reflects the infrared light in the entire range that receives infrared irradiation from the heat source,
The reflecting member is supported only by the reinforcing member, and a part of the reflecting member wraps around a surface opposite to the surface on which the heat source is disposed with respect to the reinforcing member. constant Chakusochi it said that you are. An image forming apparatus comprising the fixing device according to claim 1 .

Images