JP3749797B2 - Conveying roller and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conveyance roller for conveying a paper sheet and an image forming apparatus.
[0002]
[Prior art]
In an office machine, a paper sheet is conveyed by a conveyance roller. A conventional conveyance roller will be described. First, the conveyance roller 100 shown in FIG. 8 is an example in which a rubber roller 102 is fixedly provided on a metal drive shaft 101. However, if the diameter of the metal drive shaft 101 is reduced for weight reduction or the like, a desired outer surface is provided. In order to mold the rubber roller 102 having a diameter, it is necessary to increase the thickness of the rubber roller 102. However, the outer diameter of the rubber roller 102 becomes non-uniform due to shrinkage when the rubber roller 102 is thickened during molding. Further, when used in a high temperature environment, the rubber roller 102 needs to be molded from a material having high heat resistance. An example of the material having high heat resistance is “elastomer AR”. This elastomer AR (trade name) is a thermoplastic elastomer having a styrene block polymer as a main raw material and excellent properties such as rubber elasticity and heat resistance. Such materials are very expensive. In addition, the manufacturing cost is increased including the use of the metal drive shaft 101.
[0003]
For this reason, a conveyance roller 103 as shown in FIG. 9 has been developed. This is because a hollow drive shaft 104 made of synthetic resin is molded, and a rubber material such as the above-mentioned thermoplastic elastomer is injected into a molding die on which the drive shaft 104 is mounted. The part 105 is molded integrally.
[0004]
The reason for making the drive shaft 104 hollow is to increase the outer diameter of the drive shaft 104 with as little material as possible, thereby making it possible to reduce the thickness of the roller portion 105 and uniform the outer diameter of the roller portion 105. This is because the roller portion 105 is molded with a small amount of material because it is expensive. Further, in order to use in a high temperature environment, a support member (not shown) formed of glass-filled resin is provided, and the drive shaft 104 rotatably supported by this support member is made of a fluorine-containing resin having a low friction coefficient. The molding is performed by. However, the material is expensive.
[0005]
Incidentally, as shown in FIG. 10, when the paper sheet S is transported by the transport roller 103 and the pinch roller 106, the paper sheet S that has passed through the nip portion between the transport roller 103 and the pinch roller 106 is in the transport path. The thrust may be weakened by the resistance, and the rear end may remain stagnant while remaining on the outer periphery of the pinch roller 106. In such a case, the sheet S to be conveyed next enters the lower side of the preceding sheet S, and the page order may be out of order or a jam may occur.
[0006]
For this reason, as shown in FIG. 11, the protrusion 107 for kicking out the trailing edge of the paper sheet S that has passed through the nip portion between the conveying roller 103 and the pinch roller 106 is provided with a roller portion 105 of the conveying roller 103. There is a conventional example integrally formed on the outer periphery of the end portion of each of them.
[0007]
[Problems to be solved by the invention]
Since the conveyance roller 103 shown in FIG. 9 has a hollow drive shaft 104 and a large outer diameter, the thickness of the roller portion 105 can be reduced. Thereby, while making the outer diameter of the roller part 105 uniform, the material for shape | molding the roller part 105 can be decreased. However, in order to avoid a state in which the hollow drive shaft 104 is deformed by the injection pressure when the roller portion 105 is molded on the drive shaft 104, a gas injection type molding machine that fills the drive shaft 104 with a predetermined pressure gas. Must be used. This increases the molding cost. In addition, the hollow drive shaft 104 can be thinned, but since the outer diameter is increased, there is little effect in terms of reducing the cross-sectional area, and the roller portion 105 exists. Since the outer diameter becomes thick over the entire length including the portion that is not, the material cost is limited.
[0008]
As shown in FIG. 11, in the case where the protrusion 107 is integrally formed on the outer peripheral surface of the roller unit 105 that contacts the paper sheet S, the protrusion length of the protrusion 107 cannot be increased. I ca n’t kick it out. In addition, while the paper sheet S is being transported by the transport roller 103 and the pinch roller 106, the paper sheet S is pressed by the protrusion 107, so that the roller portion of the protrusion 107 and the pinch roller 106 is shown in FIG. If the distance d between the end portions 108 is not long enough, the paper sheet S is broken. Increasing the distance d increases the overall length of the roller portion 105, which is disadvantageous when molding the roller portion 105 with an expensive material such as the thermoplastic elastomer described above.
[0009]
  The present invention has been made in view of these points, and a first object is to reduce the material cost, make the outer diameter of the roller portion uniform, and perform molding without using a gas injection type molding machine. CanA conveyance roller that can avoid the phenomenon that the leading edge of the paper sheet to which the roller portion is added is curved even when the interval between adjacent roller portions is wide.Is to provide. The second object is to provide a transport roller that can reliably feed the trailing edge of the paper sheet downstream of the nip portion with the pinch roller when the paper sheet is transported in cooperation with the pinch roller. That is.
[0010]
[Means for Solving the Problems]
  The conveyance roller according to claim 1 is a synthetic resin drive shaft in which a flange having a thin thickness in the axial direction of the shaft portion is formed integrally with a portion of the shaft portion, and a thermoplastic synthetic resin having elasticity. A roller portion molded on the flange so as to surround the flange with resin.And an annular rib having a radius substantially equal to the radius of the roller portion is arranged between the adjacent roller portions and integrally formed on the shaft portion. Drive shaftSince the flange is provided in the portion forming the roller portion, the diameter of the shaft portion can be reduced. Since the roller part is molded so as to surround the flange, it is possible to mold a roller part of a desired size with a thin and uniform thickness.. And even when the space | interval of an adjacent roller part is wide, it becomes possible to support the part of the paper sheet between roller parts with an annular rib.
[0011]
According to a second aspect of the present invention, in the invention according to the first aspect, the plurality of flanges are arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion.
Therefore, when molding a roller part having a long axial length, the thickness of each part of the roller part can be made uniform.
[0012]
According to a third aspect of the present invention, there is provided the conveying roller according to the second aspect, wherein the plurality of flanges arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion are the shafts. It is continued by a plurality of ribs extending radially outward from the outer periphery of the part.
Accordingly, when the drive shaft is molded, the fluidity of the material between adjacent flanges is improved.
[0013]
According to a fourth aspect of the present invention, in the invention according to the third aspect, when the number of the flanges arranged in the axial direction of the shaft portion in units of one roller portion is three or more, The outer diameter of the flange located in the portion is set larger than the outer diameter of the flange located on both sides by a predetermined dimension.
Therefore, even when the material is pulled to both sides in the axial direction due to shrinkage when the roller portion is molded, it is possible to avoid a phenomenon in which the shape of the central outer peripheral surface of the roller portion is recessed in a concave shape due to sink marks.
[0015]
  Claim5The conveying roller according to claim 1,3 or 4 descriptionIn this invention, a cylindrical portion having a diameter smaller than the outer diameter of the roller portion is integrally formed on the end surface of the roller portion, and the tubular portion protrudes outward from the outer periphery of the roller portion to be conveyed. A bendable kick-out piece for kicking the rear end of the leaf is integrally formed. Therefore, in the conveyance process in which the paper sheet is in contact with the outer peripheral surface of the roller portion, the kick-out piece can be retracted to the center side of the roller portion from the surface that coincides with the outer peripheral surface of the roller portion. Further, when the trailing edge of the paper sheet is separated from the outer periphery of the roller portion, the roller portion can be rotated in a state where the tip of the kick-out piece protrudes outside the outer periphery of the roller portion.
[0016]
  Claim6The transport roller described in claim5In the described invention, the kick-out piece extends from a part of the outer periphery of the cylindrical portion in a tangential direction toward the rear in the rotation direction of the drive shaft. Therefore, the kick-out piece can be brought into contact with the paper sheet at a portion having a high degree of freedom away from the base portion continuous with the cylindrical portion.
[0017]
  Claim7The image forming apparatus according to claim 1, wherein the toner image is created on the surface of the photosensitive member, and the toner image is transferred to a transfer sheet and fixed.5 or 6Transport rollers. Therefore, claims 1, 2, 3, 4,Invention of 5 or 6It is possible to obtain the same effect as.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
First, with reference to FIG. 1, the internal structure of an image forming apparatus on which the conveyance roller of the present invention is mounted will be described. Reference numeral 1 denotes an apparatus main body. An image reading device 2 for reading an image of a document is mounted on the upper portion of the apparatus main body 1, and a process cartridge 3 is provided inside. Below the process cartridge 3 is formed a paper transport path 4 for guiding the transfer paper S, which is a paper sheet.
[0019]
The image reading apparatus 2 includes a reading unit 5 that reads a document image, and a document tray 6 on which a document to be supplied to the reading unit 5 is placed. The document tray 6 has a horizontal position A about a fulcrum shaft 7. To a standing position B indicated by a two-dot chain line. The document tray 6 is configured to be stabilized at the horizontal position A and the standing position B by a stopper (not shown).
[0020]
The process cartridge 3 is formed by rotatably providing a photoconductor 9 on a photoconductor case 8 formed in a case shape, and arranging and attaching a charging brush roller 10 and a developing unit 11 around the photoconductor 9. Has been. A transfer portion 12 facing the outer periphery of the lower portion of the photoconductor 9 is provided on the apparatus main body 1 side. The developing unit 11 is in contact with the photosensitive member 9, a developing case 13 that is detachably attached to the photosensitive member case 8, a rotatable stirrer 14 that stirs the developer stored in the developing case 13, and the photosensitive member 9. A developing roller 15, a supply roller 16 that supplies developer to the developing roller 15, and a blade 17 that is in contact with the developing roller 15 are provided. Further, a latent image forming unit 18 is provided on the upper part of the process cartridge 3 to form an electrostatic latent image by scanning a laser beam modulated based on an image signal on a charged portion of the photosensitive member 9.
[0021]
A tray 19 is provided on one side of the apparatus main body 1 to support a document read by the image reading apparatus 2 and support the transfer paper S in an obliquely loaded state. By being in elastic contact with the sheet feeding roller 20, the sheet feeding roller 20 that is rotationally driven, the pressing plate 21 that is biased in one direction and presses the transfer sheet S on the tray 19 against the sheet feeding roller 20, respectively. A separation pad 22 and a separation roller 23 that prevent double transfer of the transfer paper S are provided.
[0022]
The paper feed roller 20, the separation pad 22, and the separation roller 23 are disposed on the entrance side of the paper conveyance path 4. A bottom path 24 located downstream of the paper feed roller 20 is communicated with the paper transport path 4. Further, a fixing unit 25 for fixing the image transferred onto the transfer paper S is disposed on the downstream side of the paper transport path 4.
[0023]
Further, the apparatus main body 1 is formed with a paper stacker 26 disposed between the fixing unit 25 and the document tray 6. The sheet stacker 26 has a receiving plate 27 that supports the transfer sheet S and is positioned on the lower extension surface of the document tray 6 when the document tray 6 is rotated to the standing position B. Further, near the side surface of the apparatus main body 1 on the side opposite to the tray 19, the transfer paper S discharged from the fixing unit 25 is discharged in the horizontal direction, and the paper discharged from the fixing unit 25. A reverse paper discharge path 29 that reverses the transfer paper S and leads it to the paper stacker 26 is formed.
[0024]
A conveying roller 30 and a pinch roller 31 pressed against these conveying rollers 30 are disposed at the upper and lower portions of the reverse discharge path 29 that is a part of the conveying path of the transfer sheet S. A switching claw 32 for switching the discharge direction of the transfer sheet S is rotatably provided at a branch point between the reverse discharge path 29 and the discharge outlet 28.
[0025]
Next, an image reading operation and a printing operation will be described. When reading an image of a document, the document tray 6 is maintained at a horizontal position A as shown by a solid line in FIG. An image of the supplied original is read by the reading unit 5 and is supported on the tray 19 in a leaning state. The image read in this way is transmitted to the outside (use form as a facsimile transmission mode), or the transfer sheet S is fed from the tray 19 and the read image is printed on the transfer sheet S (as a copying machine). Use form). Alternatively, an image transmitted from the outside can be printed on the transfer paper S (use form as a facsimile reception mode).
[0026]
In the case of printing, in FIG. 1, the surface of the photoconductor 9 is charged by the charging brush roller 10 while being rotated in the clockwise direction, and the latent image forming unit is based on the read image of the document or the image received from the outside. The electrostatic latent image is formed on the charged portion of the photoconductor 9 by 18, and this electrostatic latent image is developed by the developing unit 11. This developed image is transferred to the transfer paper S fed from the tray 19 by the paper feed roller 20. The transfer sheet S on which the image has been transferred is fixed when passing through the fixing unit 25, and is discharged to the sheet discharge outlet 28 or the sheet stacker 26 depending on the direction of the switching claw 32.
[0027]
Here, a specific configuration of the transport roller of the present invention will be described with reference to FIGS. In this example, the conveyance roller and the pinch roller described below discharge the fixed transfer sheet S in the same manner as the conveyance roller 30 and the pinch roller 31 provided in the reverse sheet discharge path 29 (conveyance path) in FIG. It is attached to the position, but is not limited to this.
[0028]
  FirstThe first embodiment of the present invention, excluding the depiction of an annular rib (see FIG. 5) formed integrally with the shaft portion 33 and having a radius substantially equal to the radius of the roller portion 36.Is shown in FIG. The conveying roller 30 includes a synthetic resin drive shaft 35 in which a plurality of flanges 34 having a thin thickness in the axial direction of the shaft portion 33 are formed integrally with a portion of the shaft portion 33, and an elastic thermoplastic. And a roller portion 36 that is outsert-molded so as to surround the flange 34.
[0029]
Since the fixing unit 25 shown in FIG. 1 generates high heat, the housing 25a is formed of a synthetic resin containing glass in order to increase rigidity. Accordingly, the drive shaft 35 rotatably supported by the housing 25a is molded from fluorine-containing polycarbonate in order to reduce rotational friction. A plurality of the flanges 34 are arranged at predetermined intervals along the axial direction of the shaft portion 33 in units of one roller portion 36. Since the roller unit 36 is used in a high-temperature environment near the fixing unit 25, the above-described “elastomer AR” is used.
[0030]
In such a configuration, the transfer sheet S is nipped and conveyed by the conveyance roller 30 and the pinch roller 31. In this case, since the drive shaft 35 of the transport roller 30 includes the flange 34 at a portion where the roller portion 36 is formed, the diameter of the shaft portion 33 can be reduced. Since the portion forming the flange 34 is small, even if the drive shaft 35 is molded using an expensive material such as a polycarbonate containing fluorine, it can be molded with a small amount of material.
[0031]
Moreover, since the roller part 36 is shape | molded so that the flange 34 may be enclosed, the outer diameter of a desired magnitude | size can be obtained, without increasing thickness. Thereby, even if expensive materials, such as elastomer AR, are used, the roller part 36 can be shape | molded with few materials. Further, even if the difference between the outer diameter of the shaft portion 33 and the outer diameter of the roller portion 36 is large, the thickness of the roller portion 36 can be made thin and uniform due to the presence of the flange 34, so the roller portion 36 is molded. In this case, no shrinkage occurs due to the contraction, and the outer diameter of the roller portion 36 can be uniformly determined. Furthermore, since the drive shaft 35 includes the flange 34 for molding the roller portion 36, it is not necessary to hollow out the shaft portion 33 and increase the outer diameter in order to mold the roller portion 36 having a desired size. . Thereby, it is not necessary to use a gas injection type molding machine when molding the roller portion 36, and the molding cost can be reduced.
[0032]
Further, in this example, since the plurality of flanges 34 are arranged at predetermined intervals along the axial direction of the shaft portion 33 in units of one roller portion 36, the roller portion having a longer axial length. Even in the case of molding 36, the material for molding the roller portion 36 can be reduced, and the thickness of each portion of the roller portion 36 can be made uniform so that the outer diameter can be determined uniformly.
[0033]
  nextThe second embodiment of the present invention, excluding the depiction of the annular rib (see FIG. 5) formed integrally with the shaft portion 33 and having a radius substantially equal to the radius of the roller portion 36.Will be described with reference to FIG. In this embodiment and other embodiments that follow this embodiment, the same portions as those of the above embodiment are denoted by the same reference numerals, and the description thereof is also omitted. In the present embodiment, the plurality of flanges 34 arranged at predetermined intervals along the axial direction of the shaft portion 33 are continued by a plurality of ribs 37 extending radially outward from the outer periphery of the shaft portion 33. ing. In this example, four ribs 37 are formed radially.
[0034]
In such a configuration, when the drive shaft 35 is molded, the fluidity of the material between the adjacent flanges 34 is improved, so that the dimensional shape of the flange 34 can be determined correctly without causing insufficient filling of the material. In addition, the strength can be increased by the rib 37.
[0035]
  nextThe third embodiment of the present invention, excluding the depiction of the annular rib (see FIG. 5) formed integrally with the shaft portion 33 and having a radius substantially equal to the radius of the roller portion 36.Will be described with reference to FIG. In the present embodiment, the outer diameter of the flange 34 is different when the number of the flanges 34 arranged along the axial direction of the shaft portion 33 is three or more in units of one roller portion 36 (see FIG. 2). .
[0036]
In this case, FIG. 4A shows an example in which the number of the flanges 34 is three, and the outer diameter of one flange 34 located at the center is set to b and the outer diameters of the flanges 34 on both sides are set to a smaller than b. is there. When the number of the flanges 34 is four as shown in FIG. 4B, the outer diameters of the two flanges 34 located at the center (corresponding to the outer diameter b of FIG. This is slightly larger than the outer diameter of the flange 34 (corresponding to the outer diameter a in FIG. 4A). As shown in FIG. 4C, when the number of flanges 34 is three or more and an odd number, the outer diameter may be changed stepwise from the flange 34 located at the center to the flanges 34 located on both sides. Good. Of course, the outer diameters of the three flanges 34 located at the central portion (corresponding to the outer diameter b of FIG. 4A) are made equal, and the outer diameters of the flanges 34 on both sides (the outer diameters of FIG. 4A). (equivalent to a) may be reduced.
[0037]
In such a configuration, when the roller portion 36 (see FIG. 2) is molded, even if the material is pulled to both sides in the axial direction due to shrinkage, the shape of the central outer peripheral surface of the roller portion 36 is slightly caused by the sink. It is possible to avoid the phenomenon of recessing in a concave shape. Thereby, the uniformity of the outer diameter of the roller part 36 can further be improved.
[0038]
  nextAn annular rib formed integrally with the shaft portion 33 and having a radius substantially equal to the radius of the roller portion 36 will be described with reference to FIG. The annular ribs 38 are arranged between the adjacent roller portions 36.
[0039]
When the annular rib 38 is not present, the transfer sheet S may be curved toward the shaft portion 33 between the adjacent roller portions 36 as indicated by a two-dot chain line in FIG. In this case, if the switching claw 32 shown in FIG. 1 is disposed between the roller portions 36, the leading edge of the transfer sheet S may be caught by the switching claw 32 and broken. However, in the present embodiment, even when the interval between the adjacent roller portions 36 is wide, the portion of the transfer paper S between the roller portions 36 can be supported by the annular rib 38, so that the transfer paper that passes through the roller portion 36. It is possible to avoid the phenomenon that the leading edge of S curves into a waveform. Thereby, even if the switching claw 32 is provided in the conveyance path, the leading edge of the transfer paper S is not caught by the switching claw 32 and is not torn. Moreover, since the number of the roller parts 36 which use an expensive material can be decreased by forming the annular rib 38 in the axial part 33, it can contribute to a cost reduction.
[0040]
  nextThe fourth embodiment of the present invention, excluding the depiction of an annular rib (see FIG. 5) formed integrally with the shaft portion 33 and having a radius substantially equal to the radius of the roller portion 36.Will be described with reference to FIGS. A cylindrical portion 39 having a smaller diameter than the outer diameter of the roller portion 36 is integrally formed on the end surface of the roller portion 36, and the cylindrical portion 39 protrudes outward from the outer periphery of the roller portion 36 to be transferred. A bendable kick-out piece 40 for kicking the rear end of S is integrally formed.
[0041]
In such a configuration, as shown in FIG. 7, when the transport roller 30 rotates in the clockwise direction, the locus that the tip of the kick-out piece 40 protrudes from the outer periphery of the roller portion 36 as indicated by a two-dot chain line is drawn. In the conveyance process in which the transfer sheet S is in contact with the outer peripheral surface of the roller portion 36, the kick-out piece 40 is located on the center side of the roller portion 36 (the drive shaft 35) from the surface that coincides with the outer peripheral surface of the roller portion 36. It is possible to retreat to the center side. As a result, the transfer sheet S can be prevented from being creased by the kick-out piece 40. As shown in FIG. 7, when the trailing edge of the transfer sheet S moves away from the outer periphery of the roller portion 36, the trailing edge of the transfer sheet S is kicked out by the kicking piece 40 to be predetermined from the outer periphery of the pinch roller 31. They can be separated by a distance c. Accordingly, the trailing edge of the transfer sheet S can be sunk downward by its own weight, and the phenomenon that the transfer sheet S that is transported next enters the lower side of the transfer sheet S that has been transported first can be avoided.
[0042]
In the present embodiment, as shown in FIG. 7, the kick-out piece 40 extends from a part of the outer periphery of the cylindrical portion 39 in a tangential direction toward the rear in the rotational direction (clockwise) of the drive shaft 35. Therefore, the kick-out piece 4 can be brought into contact with the transfer sheet S at a portion with a high degree of freedom away from the base portion continuous with the cylindrical portion 39. As a result, the pressure of the kick-out piece 40 against the transfer paper S can be further reduced, and the burden on the base portion of the kick-out piece 40 that is continuous with the cylindrical portion 39 is less likely to bend and is reduced. Can be increased.
[0043]
This is because the shaft portion 33 is made thinner by using the drive shaft 35 in which the flange 34 for reducing the thickness of the roller portion 36 is formed on the shaft portion 33, thereby providing the kick-out piece 40. This is because the outer diameter of the cylindrical portion 39 can be made smaller than the outer diameter of the roller portion 36.
[0044]
【The invention's effect】
  The conveyance roller according to claim 1 is a synthetic resin drive shaft in which a flange having a thin thickness in the axial direction of the shaft portion is formed integrally with a portion of the shaft portion, and a thermoplastic synthetic resin having elasticity. Since the roller is molded on the flange so as to surround the flange with resin, the drive shaft is provided with the flange integrally with the portion forming the roller portion, so that the diameter of the shaft portion can be reduced. In addition, since the portion forming the flange is small, even if an expensive material is used, the drive shaft can be molded with a small amount of material. Furthermore, since the roller portion is molded so as to surround the flange, the thickness of the roller portion can be reduced even if the outer diameter is increased. Thereby, even if it uses an expensive material, a roller part can be shape | molded with few materials. Furthermore, even if the difference between the outer diameter of the shaft part and the outer diameter of the roller part is large, the thickness of the roller part can be made thin and uniform due to the presence of the flange. Thus, no sink marks are generated, and the outer diameter of the roller portion can be determined uniformly. Further, since it is not necessary to hollow out the shaft portion of the drive shaft and increase the outer diameter, it is not necessary to use a gas injection type molding machine when molding the roller portion, thereby reducing the molding cost.. Further, the shaft portion is formed integrally with an annular rib having a radius substantially equal to the radius of the roller portion, and is arranged between the adjacent roller portions. Even in a wide case, the portion of the paper sheet between the roller portions can be supported by the annular rib. Thereby, it is possible to avoid the phenomenon that the leading edge of the paper sheet passing through the roller portion is curved in a waveform. Thereby, even if the switching claw for switching the sheet conveyance direction is provided in the conveyance path, the leading edge of the sheet is not caught by the switching claw and broken.
[0045]
In the invention according to claim 1, a plurality of the conveying rollers according to claim 2 are arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion. Even when molding a roller part with a longer axial length, the material for molding the roller part can be reduced, and the thickness of each part of the roller part should be made uniform and the outer diameter should be made uniform. Can do.
[0046]
According to a third aspect of the present invention, there is provided the conveying roller according to the second aspect, wherein the plurality of flanges arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion are the shafts. Since it is continued by a plurality of ribs extending radially outward from the outer periphery of the part, the fluidity of the material between adjacent flanges is improved when the drive shaft is molded. Therefore, the dimensional shape of the flange can be correctly determined, and the strength can be increased.
[0047]
According to a fourth aspect of the present invention, in the invention according to the third aspect, when the number of the flanges arranged in the axial direction of the shaft portion in units of one roller portion is three or more, Since the outer diameter of the flange located at the portion is determined to be larger than the outer diameter of the flange located at both sides by a predetermined dimension, when the roller portion is molded, the material is pulled to both sides in the axial direction due to shrinkage. Even so, it is possible to avoid a phenomenon in which the shape of the central outer peripheral surface of the roller portion is slightly concave due to sink marks. Thereby, the outer diameter of a roller part can be made further uniform.
[0049]
  Claim5The conveying roller according to claim 1,3 or 4 descriptionIn this invention, a cylindrical portion having a diameter smaller than the outer diameter of the roller portion is integrally formed on the end surface of the roller portion, and the tubular portion protrudes outward from the outer periphery of the roller portion to be conveyed. Since the bendable kicking piece that kicks out the rear end of the leaf is integrally formed, in the conveyance process in which the paper sheet is in contact with the outer peripheral surface of the roller portion, the kicking piece is in contact with the outer peripheral surface of the roller portion. It is possible to retract to the center side of the roller portion from the matching surface. As a result, it is possible to avoid crease the paper sheet with the kicking piece. Further, when the trailing edge of the paper sheet is separated from the outer periphery of the roller portion, the trailing edge of the paper sheet can be kicked out by the kicking piece and separated from the roller portion. As a result, it is possible to avoid a phenomenon in which the next sheet to be conveyed enters the lower side of the sheet that has been discharged in advance.
[0050]
  Claim6The transport roller described in claim5In the described invention, the kick-out piece extends from a part of the outer periphery of the cylindrical portion in a tangential direction toward the rear in the rotation direction of the drive shaft. The sheet can be brought into contact with a portion having a high degree of freedom away from the continuous base. As a result, the pressure of the kick-out piece against the paper sheet can be further reduced, and the burden on the base portion of the kick-out piece that is difficult to bend continuously with the cylindrical portion can be reduced and the durability can be improved. .
[0051]
  Claim7The image forming apparatus according to claim 1, wherein the toner image is created on the surface of the photosensitive member, and the toner image is transferred to a transfer sheet and fixed.5 or 6And a transfer roller.Invention of 5 or 6The same effect can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing a schematic structure of an image forming apparatus on which a conveyance roller of the present invention is mounted.
[Figure 2]First embodiment of the present invention excluding the depiction of the annular ribFIG. 4 is a front view in which only the transport roller is vertically cut.
[Fig. 3]Second embodiment of the present invention without the depiction of the annular rib(A) is a front view of a drive shaft, (b) is a vertical side view of the drive shaft.
[Fig. 4]Third embodiment of the present invention without the depiction of the annular ribIt is a front view of the drive shaft in.
[Figure 5]Form related to annular ribFIG. 4 is a front view in which only the transport roller is vertically cut.
[Fig. 6]A fourth embodiment of the present invention excluding the depiction of the annular ribFIG. 3 is a front view showing a part of the conveying roller in section.
FIG. 7 is a side view showing the action of the kick-out piece.
FIG. 8 is a longitudinal sectional front view of a conveyance roller as a first conventional example.
FIG. 9 is a longitudinal front view of a conveying roller as a second conventional example.
FIG. 10 is a side view showing a state in which a paper sheet is conveyed by a conventional conveying roller.
FIG. 11 is a perspective view of a conveyance roller and a pinch roller as a third conventional example.
FIG. 12 is a front view showing a state in which a paper sheet is conveyed.
[Explanation of symbols]
  3 Process cartridge
  9 Photoconductor
29 Transport route
30 Transport roller
33 Shaft
34 Flange
35 Drive shaft
36 Roller part
37 ribs
38 annular rib
39 Cylindrical part
40 kicking piece
  S paper sheet

Claims (7)

A synthetic resin drive shaft in which a flange having a thin thickness in the axial direction of the shaft portion is formed integrally with a portion of the shaft portion, and the flange is surrounded by a thermoplastic synthetic resin having elasticity. In a conveying roller comprising a roller portion molded on the flange,
The conveying roller according to claim 1, wherein an annular rib having a radius substantially equal to a radius of the roller portion is arranged on the shaft portion so as to be integrally formed between the adjacent roller portions.   The conveying roller according to claim 1, wherein a plurality of the flanges are arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion.   The plurality of flanges arranged at predetermined intervals along the axial direction of the shaft portion in units of one roller portion are continued by a plurality of ribs extending radially outward from the outer periphery of the shaft portion. The conveying roller according to claim 2.   When the number of the flanges arranged in the axial direction of the shaft portion in one roller unit is three or more, the outer diameter of the flange located in the center portion is set to the flanges located on both sides. The conveying roller according to claim 3, wherein the conveying roller is determined to be larger than the outer diameter by a predetermined dimension.   A cylindrical portion having a smaller diameter than the outer diameter of the roller portion is integrally formed on the end surface of the roller portion, and the rear end of the paper sheet that protrudes outward from the outer periphery of the roller portion to be conveyed. The conveying roller according to claim 1, 2, 3, or 4, wherein a bendable kicking piece for kicking out the roller is integrally formed.   The conveying roller according to claim 5, wherein the kick-out piece extends from a part of the outer periphery of the cylindrical portion in a tangential direction toward the rear in the rotation direction of the drive shaft.   An image forming apparatus for creating a toner image on the surface of a photoconductor and transferring and fixing the toner image onto a transfer sheet, comprising the conveying roller according to claim 1, 2, 3, 4, 5 or 6. An image forming apparatus.

Images