JP4569516B2 - HOLDING MEMBER, CONVEYING DEVICE HAVING THE SAME, AND IMAGE FORMING DEVICE HAVING THE SAME - Google Patents

Description

  The present invention relates to a holding member that applies a nip force to a roll that conveys a sheet material, a conveying device that includes the holding member, and an image forming apparatus that includes the conveying device.

  Conventionally, as a means for applying a nip force for sandwiching a sheet material to a sheet material conveyance roll provided in the conveyance device, a spring is disposed between a bearing member of the conveyance roll and a frame member of the image forming apparatus. Some apply a nip force to the transport roll by a spring force.

  In this case, since the spring force is received by the frame member, there is a problem that the frame member is deformed and the nip force varies. Further, when the frame member is deformed due to deterioration with time or the like, there is a problem that the nip force applied to the transport roll fluctuates.

  For example, in a registration roll that transports after aligning the leading edge of the sheet material against the nip portion of the transport roll, if the nip force is weak, the leading edge of the thick paper penetrates from the nip section of the transport roll in the case of thick paper. The problem that cannot be aligned occurs.

  Further, if the nip force fluctuates during conveyance of the sheet material, the conveyance speed of the sheet material may fluctuate and image distortion may occur. In recent years, in particular, there is a case where the frame member is molded from a resin due to a demand for a reduction in size and weight of the apparatus, and the deformation due to deterioration with time of the frame member appears remarkably. Furthermore, as a result of promoting the downsizing, it may be difficult to secure a space for arranging the spring between the frame member and the bearing member.

Therefore, a conveying device is disclosed that applies a nip force to the nip portion by disposing a spring between the bearing member of the driving roll and the bearing member of the driven roll. (Patent Document 1)
In this transport device, the reaction force of the spring acts on the bearing members of both rolls and does not act directly on the frame member. Therefore, the conventional problem that the frame member is deformed by the reaction force of the spring and the nip force fluctuates is eliminated.
JP 08-26519 A

  However, in this transport device, the bearing member of the drive roll is supported by the frame member and screwed. For this reason, when the frame member is deformed due to deterioration over time, it is conceivable that the nip force of the transport roll fluctuates.

  Further, since the reaction force of the spring acts as a bending force of the bearing member, it is conceivable that the nip force varies due to the deformation of the bearing member.

  In view of the above facts, the present invention has a problem of giving a stable nip force to the transport roll.

A holding member according to a first aspect of the present invention is a holding member that applies a nip force to a first roll and a second roll that sandwich and convey a sheet material, and is a first member that is disposed on a rotation shaft of the first roll. A hook portion that hooks the outer peripheral surface of the cylindrical body from a direction orthogonal to the rotational axis direction, and a sandwiching portion that sandwiches the second cylindrical body disposed on the rotational axis of the second roll from a direction orthogonal to the rotational axis direction An opening formed between the hook portion and the clamping portion and through which the first cylindrical body and the second cylindrical body can pass, and a guide portion protruding toward the second cylindrical body, And a holder that is supported by the guide portion and is positioned between the holder and the second cylindrical body when the holder is mounted across the first cylindrical body and the second cylindrical body, A bullet that urges a cylindrical body toward the first cylindrical body And body, is formed on the first cylindrical body, with fits into the hook portion, a first rib for restricting the movement of the rotational axis of the first cylindrical body, is formed in the second cylindrical member, the clamping portion And a second rib for restricting movement of the second cylindrical body in the direction of the rotation axis .

  According to the above configuration, the holder straddles the first cylinder disposed on the rotation axis of the first roll and the second cylinder disposed on the rotation axis of the second roll, and the holder and the second cylinder The elastic body positioned therebetween urges the second cylindrical body toward the first cylindrical body and applies a nip force to the first roll and the second roll.

  Since the bearing is supported by the frame member and is not screwed to the frame member as in the prior art, the holding member gives a stable nip force to the first roll and the second roll even if the frame member is deformed. be able to.

  The holding member according to claim 2 of the present invention is the holding member according to claim 1, wherein the elastic body is a compression spring, and a guide portion through which the compression spring is inserted is provided in the holder. To do.

  According to the above configuration, since the compression spring is prevented from falling by the guide portion provided in the holder, the compression spring can stably bias the second cylinder toward the first cylinder. .

  The holding member according to claim 3 of the present invention is the holding member according to claim 1 or 2, wherein the holder is formed in a plate shape, and a reaction force of the compression spring acts as an in-plane force of the holder. And

  According to the above configuration, since the reaction force of the compression spring acts as an in-plane force of the plate-shaped holder, the holder is not bent by the spring force. For this reason, a holder can be made thin and an attachment space can be made small.

  The holding member according to a fourth aspect of the present invention is the holding member according to any one of the first to third aspects, wherein the holder includes a hook portion that is hooked on an outer peripheral surface of the first cylindrical body, and the hook portion. And a clamping part that is formed to face the second cylindrical body from both sides.

  According to the above configuration, the hook portion provided in the holder is hooked on the outer peripheral surface of the first cylindrical body to hold the first cylindrical body, and the second cylindrical body is formed by the clamping portion formed to face the hook portion. Is held from both sides. In this way, the holder reliably holds the first cylinder and the second cylinder.

  A conveying device according to a fifth aspect of the present invention is the conveying device in which a nip force is applied to the first roll and the second roll by the holding member according to any one of the first to fourth aspects. A groove or a rib into which the holder fits is formed on the outer peripheral surface of the second cylindrical body.

  According to the said structure, the groove | channel or rib which a holder fits in is formed in the outer peripheral surface of a 1st cylindrical body or a 2nd cylindrical body. By fitting the holder into the groove or rib, the holder can be prevented from falling due to the reaction force of the compression spring. Thereby, a stable nip force can be applied to the first roll and the second roll.

  A conveying apparatus according to a sixth aspect of the present invention is the conveying apparatus in which a nip force is applied to the first roll and the second roll by the holding member according to any one of the first to fourth aspects. The main body frame that supports the second roll has grooves or ribs into which the holder fits.

  According to the said structure, the groove | channel or rib in which a holder fits is formed in the main body frame. By fitting the holder into the groove or rib, the holder can be prevented from falling due to the reaction force of the compression spring. Thereby, a stable nip force can be applied to the first roll and the second roll.

  According to a seventh aspect of the present invention, in the conveyance device according to the fifth or sixth aspect, the sheet material is conveyed to the image forming unit by correcting the conveyance posture of the sheet material by the first roll and the second roll. A resist roll is configured.

  According to the said structure, the stable nip force is provided to the 1st roll and 2nd roll as a resist roll. For this reason, the sheet material can be conveyed at a predetermined timing by correcting the conveying posture of the sheet material.

  An image forming apparatus according to an eighth aspect of the present invention includes the conveyance device according to any one of the fifth to seventh aspects.

  According to the above configuration, the image forming apparatus includes the transport device according to any one of claims 5 to 7. As a result, the sheet material can be stably nipped and conveyed, so that a high-quality image can be obtained without image distortion.

  According to the present invention, a stable nip force can be applied to the transport roll.

  An embodiment of an image forming apparatus 10 in which a conveyance device 70 of the present invention is employed will be described with reference to FIGS.

  As shown in FIG. 8, in the image forming apparatus 10, process cartridges 14 of four colors (in this embodiment, yellow, magenta, cyan, and black) are arranged in the vertical direction.

  The process cartridge 14 includes a photoconductor cartridge 62 having a photoconductor 16 and a developing cartridge 64.

  As shown in FIG. 7, the photoconductor cartridge 62 is arranged in the lateral direction of the photoconductor 16 and the cleaning device 22, the charging roll 18, the erase lamp 24, and the cleaning device 22 disposed around the photoconductor 16. And a sub-toner replenishment unit 66 provided.

  The sub-toner supply unit 66 is provided with a pair of support protrusions 78 extending in a direction orthogonal to the axial direction of the photoconductor 16. By inserting the support protrusion 78 into a cartridge receiving portion (not shown) of the image forming apparatus 10, the process cartridge 14 is mounted on the image forming apparatus 10.

  Further, a developing roll 86 for developing the electrostatic latent image on the photosensitive member 16 into a toner image with the developer G is disposed in the developing cartridge 64 so as to face the photosensitive member 16. Further, below the developing roll 86, a first agitation transport auger 88 and a second agitation transport auger 89 for supplying the developer G stored in the developer storage chamber 84 to the developing roll 86 are disposed.

  As a result, the developer G supplied from the first agitating and conveying auger 88 and the second agitating and conveying auger 89 adheres onto the developing roll 86, and the developing roll 86 conveys the developer G to a position facing the photoreceptor 16. To do. The electrostatic latent image formed on the photosensitive member 16 is visualized as a toner image by the developer G on the developing roll 86.

  As shown in FIG. 8, the process cartridge 14 is arranged in the order of yellow, magenta, cyan, and black from the upstream side of the paper transport path 34. An exposure device 36 for irradiating the process cartridge 14 with scanning light is disposed.

  In the exposure device 36, a semiconductor laser (not shown), a polygon mirror 40, an imaging lens 44, and a mirror 46 are disposed in a housing 38, and light from the semiconductor laser is deflected and scanned by the polygon mirror 40. The photosensitive member 16 is irradiated through the imaging lens 44 and the mirror 46. As a result, an electrostatic latent image corresponding to the image data is formed on the photosensitive member 16.

  Further, a transport unit 48 is disposed at a position facing the photoconductor 16 across the paper transport path 34. The transport unit 48 includes a pair of stretching rolls 51 and 52 provided along the side wall 10 </ b> A of the image forming apparatus 10, and a transport belt 53 wound around the stretching rolls 51 and 52. The tension roll 52 is rotated by a motor (not shown) so that the conveyor belt 53 moves.

  An adsorption roll 55 is disposed in the vicinity of the tension roll 51, and the sheet material P is electrostatically adsorbed to the conveyance belt 53 by applying a voltage to the adsorption roll 55. ing.

  Further, a transfer roll 54 is disposed on the back surface of the conveyance belt 53 at a position facing the photoconductor 16 of each color, and the transfer roll 54 and the photoconductor 16 constitute an image forming unit 74. In the image forming unit 74, the toner image on the photosensitive member 16 is transferred to the sheet material P conveyed by the conveying belt 53.

  In addition, a sheet feeding cassette 26 in which the sheet material P is stored is provided at the lower part of the image forming apparatus 10. In the vicinity of the paper feed cassette 26, a pickup roll 28 for feeding the sheet material P at a predetermined timing is provided. The sheet material P sent out from the paper feed cassette 26 by the pickup roll 28 is transported by a plurality of transport rolls 30 and a resist roll 32 provided in the transport device 70 and is sent out to the paper transport path 34 at a predetermined timing. The sheet material P sent to the sheet conveyance path 34 is transferred with a toner image by the image forming unit 74 of each color, and the toner image is fixed to the sheet material P by the fixing device 56. Then, the sheet material P on which the toner image is fixed is discharged to the discharge tray 60 by the discharge roll 58. Details of the transfer device 70 will be described later.

  Further, on the side opposite to the process cartridge 14 of the transport unit 48, both sides that transport the sheet material P to the image forming unit 74 again with the front and back sides of the sheet material P having the image fixed on one side by the fixing device 56 reversed. A reverse conveyance path 50 for printing is provided. A plurality of conveyance rolls 72 that convey the sheet material P to be reversed are disposed in the reverse conveyance path 50, and the sheet material P is conveyed through the reverse conveyance path 50 by the conveyance roll 72 and is provided in the conveyance device 70. The registration roll 32 is sent to the image forming unit 74 at a predetermined timing.

  In the image forming apparatus 10 configured as described above, an image is formed as follows.

  As shown in FIG. 8, first, the charging roll 18 to which a voltage is applied uniformly charges the surface of the photosensitive member 16 at a predetermined charging portion potential.

  Further, exposure is performed by the exposure device 36 so that the image portion on the charged photoconductor 16 has a predetermined exposure portion potential, and an electrostatic latent image is formed.

  That is, based on image data supplied from a control device (not shown), a semiconductor laser (not shown) is turned on / off and modulated to form a latent image corresponding to the image on the photoconductor 16.

  Further, as shown in FIG. 7, the developer G stirred and conveyed by the first agitating and conveying auger 88 and the second agitating and conveying auger 89 of the developing cartridge 64 is supplied to the developing roll 86, and the developer G is developed. It is attracted onto the developing roll 86 by the magnetic force of the roll 86. The adsorbed developer G is conveyed to a position facing the photoconductor 16 by the developing roller 86.

  A predetermined developing bias voltage is applied to the developing roll 86 for each color from a power supply device (not shown), and when the electrostatic latent image on the photosensitive member 16 passes the position of the developing roll 86, the developer G The toner adheres by electric force and is visualized as a toner image.

  Therefore, the sheet material P placed in the paper feed cassette 26 shown in FIG. 8 is sent to the paper transport path 34 by the pickup roll 28, and further, the registration roll 32 provided in the transport roll 30 and the transport device 70. As a result, the toner image on the photosensitive member 16 is transferred to the sheet material P. The transferred toner image is fixed by the fixing device 56, and the sheet material P on which the toner image is fixed is discharged to the discharge tray 60 by the discharge roll 58.

  Further, when images are formed on both surfaces of the sheet material P, the sheet material P discharged from the fixing device 56 is conveyed along the reverse conveyance path 50 by the conveyance roll 72, and a registration roll provided in the conveyance device 70. 32 is sent again to the image forming unit 74 at a predetermined timing. Accordingly, an image is formed on the back surface of the sheet material P in the same manner as an image is formed on the front surface of the sheet material P, and the sheet material P is discharged to the discharge tray 60 by the discharge roll 58.

  Next, the conveyance device 70 will be described in detail.

  As shown in FIG. 6, the resist roll 32 includes a first roll 33 and a second roll 35. The first roll 33 has a plurality of stepped roll portions 33B formed around a shaft 33A that is a rotating shaft, and the second roll 35 has a roll portion 35B formed around the shaft 35A. It is.

  The shaft 33 </ b> A of the first roll 33 and the shaft 35 </ b> A of the second roll 35 are rotatably supported by the paper feed frame 90. A first cylindrical body 92 is rotatably inserted at both ends of the shaft 33A, and a second cylindrical body 94 is rotatably inserted at both ends of the shaft 35A. The first cylindrical body 92 and the second cylindrical body 94 are held by a holding member 82 including a compression spring 98 and a holder 96.

  Specifically, as shown in FIG. 5, the plate-like holder 96 is provided with a guide portion 96A through which the compression spring 98 is inserted, and the second cylindrical body 94 is sandwiched so as to sandwich the guide portion 96A. A clamping portion 96B is provided. In addition, a hook portion 96C that hooks the first cylindrical body 92 is provided so as to face the sandwiching portion 96B, and the sandwiching portion 96B and the hook portion 96C are connected by a rod-like connecting portion 96D.

  Further, on the outer peripheral surface of the second cylindrical body 94, a protruding portion 94A into which the distal end portion of the compression spring 98 is fitted and a rib 94B into which the holding portion 96B of the holder 96 is fitted are provided.

  Further, on the outer peripheral surface of the first cylindrical body 92, a rib 92A in which the hook portion 96C of the holder 96 is fitted is provided. In addition, flanges 92B and 94C that abut against the side wall 90C of the paper feed frame 90 are provided at the ends of the first cylindrical body 92 and the second cylindrical body 96.

  In addition, a fixing unit 102 having a groove portion 102A in which a connecting portion 96D of the holder 96 is fitted is provided in a paper feed frame 90 to which the registration roll 32 and the like are assembled to unitize the transport mechanism. The groove portion 102A communicates with an opening portion 102B provided on the elevation surface of the fixed portion 102.

  Here, a procedure for applying a nip force to the roll part 33B and the roll part 35B and assembling the roll part 33B and the roll part 35B will be described.

  The shaft 33 </ b> A of the first roll 33 and the shaft 35 </ b> A of the second roll 35 are inserted into circular holes 90 </ b> A and 90 </ b> B provided in the paper feed frame 90. Further, the first cylindrical body 92 and the second cylindrical body 94 are inserted from the outside of the paper feed frame 90, and the flange portions 92 </ b> B and 94 </ b> C are brought into contact with the side wall 90 </ b> C of the paper feed frame 90. The circular holes 90A and 90B are provided with relief portions (not shown) so that the protrusions 94A and ribs 94B of the second cylindrical body 94 and the ribs 92A of the first cylindrical body 92 do not interfere during assembly. Yes.

  Next, as shown in FIG. 3A, the hook portion 96 </ b> C of the holder 96 into which the compression spring 98 is inserted is inserted obliquely from above through the opening 102 </ b> B of the fixing portion 102. Then, the second cylindrical body 94 is sandwiched between the clamping portions 96 </ b> B of the holder 96 while being compressed by pressing the compression spring 98 against the outer peripheral surface of the second cylindrical body 94. Further, as shown in FIG. 3B, the hook portion 96 </ b> C of the holder 96 is lifted and hooked on the outer peripheral surface of the first cylindrical body 92. In this way, as shown in FIGS. 2 and 4, the compression spring 98 urges the second cylindrical body 94 toward the first cylindrical body 92 so as to sandwich and convey the sheet material P. A nip force is applied to the resist roll 32. In FIG. 4, the flange portions 92 </ b> B and 94 </ b> C are omitted for easy understanding of the relationship between the holder 96 and the first cylindrical body 92 and the second cylindrical body 94.

  Here, since the holder 96 is a plate-like member, the reaction force transmitted to the holder 96 when the compression spring 98 is compressed acts as an in-plane force of the holder 96, so the holder 96 is bent by the spring force. Absent. For this reason, a stable nip force can be applied to the resist roll 32, and the holder 96 can be made thinner, and the mounting space can be reduced.

  In addition, the compression spring 98 is prevented from falling by a guide portion 96 </ b> A provided in the holder 96. Furthermore, the tip of the compression spring 98 is fitted into the protrusion 94A of the second cylindrical body 94, and the tip of the compression spring 98 is prevented from falling. For this reason, the compression spring 98 can stably bias the second cylindrical body 94 toward the first cylindrical body 92.

  In addition, since the registration roll 32 is held by the holding member 82 including the holder 96 and the compression spring 98, the biasing force of the compression spring 98 is not affected even if the paper feed frame 90 is deformed. For this reason, the adjustment of the nip force can be easily performed, and the conveying device 70 can be easily replaced.

  As shown in FIG. 2, the connecting portion 96 </ b> D of the holder 96 is fitted in the groove portion 102 </ b> A of the fixing portion 102, so that the connecting portion 96 </ b> D of the holder 96 is prevented from falling. For this reason, the holder 96 is prevented from falling by the reaction force of the compression spring 98.

  Further, as shown in FIG. 1, since the holding portion 96B of the holder 96 is fitted to the rib 94B and the hook portion 96C is fitted to the rib 92A, the holder 96 is prevented from falling down. Thus, the holder 96 can be reduced in size.

  Further, since the nip force of the resist roll 32 is stable in this way, the conveyed sheet material P is abutted against the nip portion and aligned, and the image forming portion 74 (see FIG. 8), the sheet material P can be fed in, and thereby a high-quality image can be obtained without image distortion.

  As shown in FIG. 6, at one end of the shaft 33A of the first roll 33, there are provided a motor gear 104 that rotates by the rotational force of a motor (not shown) and a first gear 106 that is driven to rotate. A second gear 108 and a third gear 110 that mesh with each other are provided at the other end of the shaft 33 </ b> A of the first roll 33 and the shaft 35 </ b> A of the second roll 35. That is, when the sheet material P is conveyed, the first roll 33 rotates as a driving roll, and the rotational force of the first roll 33 is transmitted to the third gear 110 via the second gear 108, and the second roll The roll 35 is driven and rotated by the first roll 33 so that the sheet material P is nipped and conveyed.

  Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor. For example, in the above embodiment, the holder 96 is prevented from falling by fitting the holder 96 to the ribs provided on the outer peripheral portions of the first cylindrical body 92 and the second cylindrical body 94, but the first cylindrical body 92 and the second cylindrical body 92 The holder 96 may be prevented from falling by providing a concave groove or the like on the outer periphery of the cylindrical body 94 and fitting the holder 96 therein.

  In the above-described embodiment, the groove portion 102 </ b> A that prevents the holder 96 from falling is provided in the paper supply frame 90. However, a rib or the like that prevents the holder 96 from falling down may be provided in the paper supply frame 90.

It is the expansion perspective view which showed the conveying apparatus which concerns on embodiment of this invention, and showed the state by which the edge part of the roll was hold | maintained with the holder. It is the side view which showed the conveying apparatus which concerns on embodiment of this invention, and showed the state by which the edge part of the roll was hold | maintained with the holder. (A) The side view which showed the conveying apparatus which concerns on embodiment of this invention, and showed the state when attaching a roll edge part to a holder. (B) It is the side view which showed the conveyance apparatus which concerns on embodiment of this invention, and showed the state when attaching a roll edge part to a holder. It is the perspective view which showed the conveying apparatus which concerns on embodiment of this invention. It is the disassembled perspective view which showed the conveying apparatus and paper feed frame which concern on embodiment of this invention. FIG. 5 is a perspective view showing the transport device according to the embodiment of the present invention and showing a state where the transport device is attached to a paper feed frame. FIG. 3 is a side view showing the inside of the process cartridge of the image forming apparatus according to the embodiment of the present invention as seen from the side. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 32 Registration roll 33 1st roll 35 2nd roll 70 Conveying device 74 Image forming part 82 Holding member 92 1st cylindrical body 92A Rib 94 2nd cylindrical body 94B Rib 96 Holder 96A Guide part 96B Clamping part 96C Hook part 98 Compression spring 102A Groove (groove)

Claims (8)

A holding member that applies a nip force to the first roll and the second roll that sandwich and convey the sheet material,
A hook portion for hooking an outer peripheral surface of the first cylindrical body disposed on the rotational axis of the first roll from a direction perpendicular to the rotational axis direction ; and a second cylindrical body disposed on the rotational axis of the second roll. A sandwiching portion sandwiched from a direction orthogonal to the rotation axis direction, an opening formed between the hook portion and the sandwiching portion and through which the first cylindrical body and the second cylindrical body can pass, and the first A holder provided with a guide portion projecting toward two cylindrical bodies ;
When the holder is supported across the first cylindrical body and the second cylindrical body, the second cylindrical body is positioned between the holder and the second cylindrical body. An elastic body biasing toward the first cylindrical body;
A first rib that is formed on the first cylindrical body, fits into the hook portion, and restricts movement of the first cylindrical body in the rotation axis direction;
A second rib that is formed on the second cylindrical body, fits in the clamping portion, and restricts movement of the second cylindrical body in the rotation axis direction;
A holding member comprising:   The holding member according to claim 1, wherein the elastic body is a compression spring, and a guide portion through which the compression spring is inserted is provided in the holder.   The holding member according to claim 1 or 2, wherein the holder is formed in a plate shape, and a reaction force of the compression spring acts as an in-plane force of the holder.   The said holder is provided with the hook part hooked on the outer peripheral surface of the said 1st cylindrical body, and the clamping part formed facing the said hook part, and clamping the said 2nd cylindrical body from both sides. Item 4. The holding member according to any one of Items 1 to 3. In the conveying apparatus in which a nip force is applied to the first roll and the second roll by the holding member according to any one of claims 1 to 4,
A conveying device, wherein a groove or a rib into which a holder fits is formed on the outer peripheral surface of the first cylindrical body or the second cylindrical body. In the conveying apparatus in which a nip force is applied to the first roll and the second roll by the holding member according to any one of claims 1 to 4,
A conveying device, wherein a groove or a rib into which a holder fits is formed in a main body frame that supports the first roll and the second roll.   7. The conveying apparatus according to claim 5, wherein a registration roll that corrects a conveying posture of the sheet material by the first roll and the second roll and conveys the sheet material to the image forming unit is formed.   An image forming apparatus comprising the transport device according to claim 5.

Images