JP2012121648A - Conveying roller and printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying roller and a printing device which can exhibit good feeding accuracy by securely positioning with a simple structure.SOLUTION: A metal plate is formed in a cylindrical shape so that a pair of opposite end surfaces 61a, 61b are in proximity to each other or abut on each other, and the pair of end surfaces have a joint line 80 extending in an axial direction. The conveying roller 15 includes a printing region 15A having a high friction layer 50 formed on a surface of a roller body 16. The high friction layer 50 is applied to an attachment region 15C on which a positioning member is attached to a bearing 26B on a drive part 30 side of the roller body 16.

Description

  The present invention relates to a conveyance roller and a printing apparatus.

  2. Description of the Related Art Conventionally, a printing apparatus that prints information on a sheet-like recording medium has been used, and this printing apparatus is provided with a conveying apparatus that conveys the recording medium. The conveyance device includes a conveyance roller that conveys a recording medium by rotating, and a driven roller that is urged and brought into contact with the conveyance roller, and the recording medium is sandwiched between the conveyance roller and the driven roller. (See, for example, Patent Document 1).

JP-A-10-67444

  However, if the position of the roller in the axial direction changes, the gear provided at the end of the transport roller may be disengaged from the drive unit (so-called gear loss), and the recording medium feeding operation may not be possible. Therefore, it has been desired to provide a technique that can simply and reliably fix the transport roller.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transport roller and a printing apparatus that have good feed accuracy by being reliably positioned with a simple configuration. .

  In order to solve the above problems, the transport roller of the present invention is formed in a cylindrical shape so that a pair of opposed end surfaces (61a, 61b) of a metal plate are close to or in contact with each other, and the pair of end surfaces are arranged in the axial direction. A conveying roller (15) having an extending seam (80) and having a printing region (15A) having a high friction layer (50) formed on the surface of the roller body (16), the driving of the roller body The high friction layer is applied to an attachment region to which the positioning member (14) is attached to the bearing (26B) on the part (30) side.

  According to the transport roller of the present invention, since the high friction layer is applied to the attachment region, it is possible to prevent the positioning member from rattling by improving the frictional force between the positioning member and the roller body. In addition, since the positioning member is fixed using the high friction layer formed in the printing region, there is no need to separately prepare parts or perform surface treatment to fix the positioning member. It is possible to prevent the manufacturing cost from increasing. Therefore, since the transport roller can be easily and reliably positioned at a predetermined position, it is possible to ensure good paper feeding accuracy.

Moreover, in the said conveyance roller, it is preferable that the said positioning member is attached by being penetrated by the roller main body.
According to this configuration, it is possible to prevent the positioning member from rattling over the entire circumference of the roller body.

Moreover, in the said conveyance roller, it is preferable that the opening part which fits the projection part provided in the said positioning member in the said attachment area | region is formed.
According to this configuration, the positioning member can be satisfactorily fixed to the predetermined position with respect to the roller body by fitting the protrusion of the positioning member into the opening.

Moreover, in the said conveyance roller, it is preferable that the said high friction layer contains the inorganic particle and this inorganic particle is comprised from an aluminum oxide.
According to this structure, it can prevent that the fine particle which consists of aluminum oxide fills the clearance gap between a positioning member and a roller main body, and a backlash arises in a positioning member.

Moreover, in the said conveyance roller, it is preferable that the content rate of the inorganic particle in the high friction layer of the said attachment area | region is set low compared with the content rate in the high friction layer of the said printing area | region.
In this case, the content of the fine particles in the mounting region is lower than that in the printing region. Therefore, in the mounting region, the frictional force between the roller body and the positioning member becomes too large, and the assembling property of the positioning member is lowered. Can be prevented.

A printing apparatus according to the present invention includes the transport roller.
According to the printing apparatus of the present invention, since the positioning member is provided with the transport roller that is favorably held by the roller body, this printing apparatus itself is also highly reliable with high feeding accuracy.

1 is a side sectional view of an ink jet printer according to an embodiment of the present invention. (A) is a top view which shows the conveyance unit of an inkjet printer, (b) is a side view which shows the drive system of a conveyance unit. (A) is a figure which shows schematic structure of a conveyance roller mechanism, (b) is a figure which shows schematic structure of a bearing, (c) is the elements on larger scale which show the principal part of a roller main body. The side view which shows the structure of a conveyance roller. The schematic diagram of the manufacturing apparatus of the conveyance roller of embodiment. It is process sectional drawing of the extraction process which concerns on this embodiment. The top view of the metal plate stamped by the 1st press. (A)-(c) is a side view which shows the bending process by a 2nd press. The side view which shows the bending process by the 2nd press machine following FIG. The top view which shows the metal plate in which the flat plate part was formed in the stepwise cylindrical shape through the process shown to Fig.9 (a)-FIG.9 (c), FIG.10 (a)-FIG.10 (c). (A)-(d) is process drawing which shows the aspect of the roll leveler process which concerns on this embodiment. (A) Perspective view of roller body, (b) is a sectional side view of a joint, and (c) is a process diagram of a centerless polishing process. (A)-(d) is a figure which shows the formation process of the high friction layer to a roller main body. The schematic block diagram of the painting booth for forming a high friction layer. The principal part enlarged view of the joint of a roller main body and its vicinity. (A)-(d) is the schematic which shows the structure of a roller main body. (A)-(c) is the schematic which shows the structure of a roller main body. (A) is a principal part perspective view of a roller main body, (b) is sectional drawing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

FIG. 1 is a side sectional view of an ink jet printer according to an embodiment of the present invention.
2A is a plan view showing a transport unit of the ink jet printer, and FIG. 2B is a side view showing a drive system of the transport unit.

  As shown in FIG. 1, an ink jet printer (printing apparatus) 1 includes a printer main body 3, a paper feeding unit 5 provided on the upper rear side of the printer main body 3, and a paper discharging unit provided on the front side of the printer main body 3. 7.

  A paper feed tray 11 is provided in the paper feed unit 5, and a plurality of recording papers (medium, recording medium, transport medium) P are stacked on the paper feed tray 11. Here, as the recording paper P, plain paper, coated paper, OHP (overhead projector) sheet, glossy paper, glossy film, and the like are used. Hereinafter, in the conveyance path of the recording paper P, the paper feed tray 11 side is referred to as an upstream side, and the paper discharge unit 7 side is referred to as a downstream side. A paper feed roller 13 is provided on the downstream side of the paper feed tray 11.

  The paper feed roller 13 is configured to sandwich the recording paper P located at the uppermost part of the paper feed tray 11 with an opposing separation pad (not shown) and send it to the downstream side. A transport roller mechanism 19 is provided on the downstream side of the paper feed roller 13.

  The transport roller mechanism 19 includes a transport roller 15 disposed on the lower side and a driven roller 17 disposed on the upper side.

  The conveying roller 15 is provided so as to sandwich the recording paper P between the driven roller 17 and to be rotationally driven by the driving unit 30 shown in FIG. Thereby, the conveyance roller 15 can convey the recording paper P to the recording head (printing unit) 21 disposed on the downstream side by a precise and accurate conveyance (paper feeding) operation accompanying the conveyance printing process. It has become.

  The recording head 21 is held by a carriage 23, and the carriage 23 is configured to reciprocate in a direction orthogonal to the paper feeding direction (the conveyance direction of the recording paper P). The printing process (printing process) by the recording head 21 is controlled by the control unit CONT. A platen 24 is disposed at a position facing the recording head 21.

  The platen 24 is composed of a plurality of diamond ribs 25 arranged at intervals along the moving direction of the carriage 23.

  The diamond rib 25 supports the recording paper P from below when printing on the recording paper P by the recording head 21, and the top surface functions as a supporting surface. The distance between the diamond rib 25 and the recording head 21 can be adjusted according to the thickness of the recording paper P. As a result, the recording paper P can smoothly pass over the top surface of the diamond rib 25. A paper discharge roller mechanism 29 is provided on the downstream side of the diamond rib 25 and the recording head 21.

The paper discharge roller mechanism 29 includes a paper discharge roller 27 disposed on the lower side and a paper discharge jagged roller 28 disposed on the upper side. The recording paper P is pulled out and discharged by the rotational drive of the paper discharge roller 27. ing.
Here, a description will be given of the relationship among the drive speeds of the driving unit 30 of the transport roller mechanism 19 and the paper discharge roller mechanism 29, the transport roller 15, and the paper discharge roller 27.

As shown in FIGS. 2A and 2B, the printer main body 3 is provided with a transport motor 32 that is driven under the control of the control unit CONT. The drive shaft of the transport motor 32 is provided with a pinion 33, and the transport drive gear 35 is engaged with the pinion 33, and the transport roller 15 is inserted and connected to the transport drive gear 35. .
Under such a configuration, the transport motor 32 and the like serve as a drive unit 30 that rotationally drives the transport roller 15.

  Further, the transport roller 15 is provided with an inner gear 39 coaxially with the transport drive gear 35 on one end side in the axial direction, and an intermediate gear 41 is engaged with the inner gear 39. A paper discharge drive gear 43 is engaged with the gear 41. The rotation shaft of the paper discharge drive gear 43 is a shaft body 45 of the paper discharge roller 27 as shown in FIG.

  Under such a configuration, the transport roller 15 of the transport roller mechanism 19 and the paper discharge roller 27 of the paper discharge roller mechanism 29 are driven by receiving the rotational driving force from the transport motor 32 that is the same drive source. It has become so.

  The rotation speed of the paper discharge roller 27 is set to be faster than the rotation speed of the transport roller 15 by adjusting the gear ratio of each gear. Accordingly, the paper discharge speed of the paper discharge roller mechanism 29 is faster than the transport speed of the transport roller mechanism 19 by an increase rate.

  Further, the holding force (pressing force) of the recording paper P by the transport roller mechanism 19 is set larger than the holding force (pressing force) by the paper discharge roller mechanism 29. Therefore, when the transport roller mechanism 19 and the paper discharge roller mechanism 29 both hold the recording paper P, the transport speed of the recording paper is independent of the paper discharge speed of the paper discharge roller mechanism 29. It is defined by the transport speed.

Next, the conveyance roller 15 and the conveyance roller mechanism 19 provided with the same will be described.
3A is a diagram illustrating a schematic configuration of the transport roller mechanism, FIG. 3B is a diagram illustrating a schematic configuration of the bearing, and FIG. 3C is a partially enlarged view illustrating a main part of the roller body 16. FIG. FIG. 4 is a side view showing the configuration of the transport roller 15.
The transport roller 15 includes a hollow cylindrical roller body (cylindrical shaft) 16 and a high friction layer (medium support region) 50 formed in a part of the surface of the roller body 16 in the longitudinal direction (axial direction). ing. On the outer peripheral surface (front surface) of the transport roller 15, a printing region 15A that contacts the recording paper P, a pair of support regions 15B provided on both sides of the printing region 15A along the axial direction, and a support region 15B on the drive unit 30 side. And an attachment region 15C provided in the vicinity of (see FIG. 4).

  The attachment region 15C is a region for attaching the positioning member 14 that positions the transport roller 15 at a predetermined position. An opening 14a is formed in the positioning member 14, and the positioning member 14 is attached to the attachment region 15C by inserting the roller body 16 through the opening 14a. The inner diameter of the opening 14a and the outer diameter of the roller body 16 are set to be substantially the same or slightly larger than the inner diameter of the opening 14a (about 20 μm).

  In the present embodiment, the roller body 16 is incorporated in the printer body 3 in a state where the position of the end portion 16A is restricted from moving to the side opposite to the drive unit 30. Therefore, the positioning member 14 in the attachment region 15C is for preventing the position of the end 16B of the roller body 16 from being displaced toward the drive unit 30.

  The positioning member 14 is attached to a position where it comes into contact with the wall surface of the bearing 26B when the transport roller 15 is held by the bearings 26A and 26B. The movement of the conveying roller 15 in the axial direction (on the drive unit 30 side) is restricted by the positioning member 14 coming into contact with the bearing 26B.

  As shown in FIGS. 3A and 4, the high friction layer 50 is selectively formed in the central portion excluding both end portions in the axial direction of the roller body 16. Specifically, the high friction layer 50 is formed from the printing region 15A to the attachment region 15C. The surface of the high friction layer 50 is fixed in a state where a sharp pointed portion of the inorganic particles is exposed, and exhibits a high frictional force.

In the high friction layer 50, resin particles are selectively applied to a predetermined region of the surface of the roller body 16 with a uniform film thickness of about 10 μm to 30 μm to form a resin film, and the inorganic particles are uniformly formed on the resin film. It is formed by spraying and then firing (see FIG. 15). As the resin particles, fine particles having a diameter of about 10 to 20 μm made of an epoxy resin or a polyester resin are preferably used. Further, as the inorganic particles, ceramic particles such as aluminum oxide (alumina; Al ₂ O ₃ ), silicon carbide (SiC), silicon dioxide (SiO ₂ ), etc., adjusted to a predetermined particle size distribution by crushing treatment are preferably used. It is done. Among these, alumina is more preferably used because it has a relatively high hardness and functions well to increase frictional resistance, and is relatively inexpensive and does not hinder cost reduction. Therefore, in this embodiment, alumina particles are used as the inorganic particles.

  Further, in this embodiment, the alumina particles are adjusted so that the particle diameter is in the range of 15 μm or more and 90 μm or less, and the weighted average particle diameter (average particle diameter) serving as the center diameter is 45 μm. Things are used.

  Thus, in the printing region 15A, the recording paper P can be supported and conveyed with high accuracy by the action of the high friction layer 50 (inorganic particles). On the other hand, in the attachment region 15C, the frictional force between the positioning member 14 and the roller main body 16 is improved by the action of the high friction layer 50 (inorganic particles), and the roller main body 16 is inserted without causing the positioning member 14 to rattle. It is assumed that Therefore, the positioning member 14 is securely held in the attachment region 15C, and the transport roller 15 is displaced along the axial direction of the roller main body 16 due to rattling or displacement in the attachment position of the positioning member 14. This prevents the occurrence of malfunctions. Therefore, the conveyance operation failure caused by so-called gear disengagement such that the conveyance driving gear 35 attached to one end portion 16B of the conveyance roller 15 is disengaged from the pinion 33 or the inner gear 39 is disengaged from the intermediate gear 41 occurs. It has been prevented.

  Moreover, in this embodiment, the content rate of the inorganic particles in the high friction layer 50 in the attachment region 15C is set lower than the content rate in the printing region 15A. In the present embodiment, as described later, the area occupied by the alumina particles 95 is set to 80% with respect to the area of the resin film 51 in the printing region 15A, and the alumina with respect to the area of the resin film 51 in the attachment region 15C. The area occupied by the particles 95 was set to 20%. According to this structure, it can prevent that the assembly property at the time of inserting the positioning member 14 in the roller main body 16 falls because frictional force becomes large too much between the roller main body 16 and the positioning member 14 in the attachment area | region 15C. .

  The roller body 16 is formed using a steel plate coil around which a metal plate such as a galvanized steel plate or a stainless steel plate is wound as a base material. The roller body 16 is bent so that a pair of end faces of the metal plate on which the coil is rewound is opposed to each other, and a cylindrical shaft formed into a cylindrical shape in which a surface that is the inner peripheral surface side of the coil is an inner peripheral surface. It is. That is, the metal plate forming the roller body 16 is formed in a cylindrical shape in a state in which the winding by the coil remains so as to warp the inner peripheral surface side of the cylinder.

  The roller body 16 has a seam 80 formed between a pair of end faces 61a and 61b of a metal plate which are bent and faced. The roller body 16 has the same circumferential direction (bending direction) and coil winding direction (metal plate rolling direction), and the seam 80 is formed substantially parallel to the axial direction of the roller body 16.

  As shown in FIGS. 3A and 4, the transport roller 15 has bearings 26 </ b> A and 26 </ b> B in which both ends (first end portion 16 f and second end portion 16 s) are integrally formed on the platen 24 (see FIG. 1). Is held rotatably. As shown in FIG. 3 (b), the bearings 26A and 26B are formed in a U-shape that opens upward, and the transport roller 15 is fitted into the U-shaped portion so that the transport roller 15 is placed on the front and rear sides and the lower side. It is supported from three directions. Then, lubricating oil (lubricant) G such as grease is supplied (applied) to the contact surface between the bearings 26 </ b> A and 26 </ b> B and the transport roller 15 (the outer peripheral surface of the transport roller 15).

  As shown in FIGS. 3A and 3C, the roller main body 16 (conveying roller 15) constituting the conveying roller 15 has a pair of end surfaces 61a and 61b forming a joint 80. An engaging portion 65 that engages a part of 61a and 61b with each other in the circumferential direction is formed. The engaging portion 65 is formed at the second end portion 16s on the drive portion 30 side in the axial direction of the roller body 16 (see FIG. 4).

  Specifically, the engaging portion 65 avoids a region where the high friction layer 50 is formed (between the printing region 15A and the mounting region 15C) and a region supported by the bearings 26A, 26B (support regions 15B, 15B). And the inner gear 39 (FIG. 3A) provided on the second end 16s side of the roller body 16 in the axial direction, and the bearing 26B closer to the inner gear 39 (FIG. 3A). )) And is preferably located as close to the drive unit 30 as possible. If the engaging portion 65 is provided in the printing region 15A, it leads to image distortion and a decrease in conveyance accuracy. Further, if the bearings 26A and 26B (FIG. 3A) are provided at the portions where the bearings 26A and 26B are disposed, there is a risk that problems such as excessive wear of the bearings 26A and 26B may occur.

  Of the pair of end surfaces 61a and 61b of the metal plate forming the joint 80, the engaging portion 65 is formed on the engaging recess 65A on the one end surface 61a side and on the other end surface 61b side. It is comprised by the hook shape with the engaging convex part 65B engaged with. The engaging convex portion 65B protrudes in the forward rotation direction of the transport roller 15, and is engaged in a state of being press-fitted into the engaging concave portion 65A. By providing such an engaging portion 65 on the side close to the driving portion 30 as described above, the strength against the rotational torque is increased, and the conveyance roller 15 can be prevented from being twisted.

  The driven roller 17 is configured by a plurality of (for example, six) rollers 17 a arranged coaxially, and is arranged at a position facing and contacting the high friction layer 50 of the transport roller 15. A biasing spring (not shown) is attached to the driven roller 17 composed of these rollers 17a, and thereby the driven roller 17 is biased toward the transport roller 15 side.

  Therefore, the driven roller 17 comes into contact with the high friction layer 50 of the transport roller 15 with a predetermined pressing force (clamping force with respect to the recording paper P) and rotates following the rotation operation of the transport roller 15. Further, the force for sandwiching the recording paper P between the transport roller 15 and the driven roller 17 is increased, and the transportability of the recording paper P is improved.

  The surface of each roller 17a of the driven roller 17 is subjected to a low wear treatment such as fluororesin coating in order to reduce damage caused by sliding contact with the high friction layer 50.

  The transport roller 15, the bearings 26 </ b> A and 26 </ b> B, the drive unit 30, the driven roller 17, and the like constitute the transport unit 20 of the inkjet printer 1. The transport unit 20 rotates the transport roller 15 with high transport accuracy supported by the pair of bearings 26 </ b> A and 26 </ b> B as described above, and supports the recording paper P by the high friction layer 50 to transport it with high precision. Can do. Moreover, since the conveyance part 20 has prevented the positional deviation of the conveyance roller 15 in the axial direction by the positioning member 14 provided in the attachment region 15C where the high friction layer 50 is formed, occurrence of gear disengagement occurs. Therefore, the recording paper P can be conveyed with high accuracy over a long period of time and has high reliability. Further, by using the high friction layer 50 as a means for holding the positioning member 14 on the roller body 16, it is not necessary to separately prepare parts or perform surface treatment in order to fix the positioning member 14. . Thereby, it can prevent that the manufacturing cost in the conveyance roller 15 increases.

  Next, the operation of the ink jet printer 1 will be described with reference to FIGS.

  The ink jet printer 1 clamps the recording paper P located at the uppermost part of the paper feed tray 11 by the paper feed roller 13 and sends it to the downstream side. The fed recording sheet P reaches the transport roller mechanism 19. The transport roller mechanism 19 sandwiches the recording paper P between the transport roller 15 and the driven roller 17, and transports the recording paper P at a constant speed toward the lower side of the recording head 21 by a paper feeding operation by rotational driving of the transport roller 15. The recording paper P conveyed below the recording head 21 is printed with high quality by the recording head 21 while smoothly passing over the top surface of the diamond rib 25. The recording paper P printed by the recording head 21 is sequentially discharged by the paper discharge roller 27 of the paper discharge unit 7.

Since the conveyance speed of the discharge roller mechanism 29 is set faster than the conveyance speed of the conveyance roller mechanism 19, the recording paper P is conveyed in a state where the back tension is applied. However, when the transport roller mechanism 19 and the paper discharge roller mechanism 29 both hold the recording paper P, the transport speed of the recording paper is defined by the transport speed of the transport roller mechanism 19. Therefore, even when the paper discharge roller mechanism 29 and the transport roller mechanism 19 perform paper discharge and transport at the same time, the transport speed of the recording paper is defined by the transport speed of the transport roller mechanism 19.
Therefore, accurate and stable paper feeding (conveyance) without unevenness of conveyance is performed.

  Here, when the recording paper P is supported and transported by the high friction layer 50 of the transport roller 15, torque acts on the roller body 16. Then, stress acts in the direction in which the joint 80 (see FIG. 4) between the pair of end surfaces 61a and 61b of the metal plate forming the roller body 16 opens. When the seam 80 of the roller body 16 is opened, the transport roller 15 does not come into uniform contact with the recording paper P, and transport unevenness occurs.

  However, in this embodiment, a part of the seam 80 in the roller body 16 of the transport roller 15 has a hook shape, and as described above, the end surfaces 61a and 61b of the metal plate forming the seam 80 of the roller body 16 An engaging portion 65 is formed. Thereby, even if rotational torque acts on the roller main body 16, it can prevent that a stress acts in the direction which the joint 80 of the end surfaces 61a and 61b opens.

The engaging portion 65 has an engaging convex portion 65B formed on one end surface 61b that forms the joint 80 so as to protrude in the forward rotation direction (direction in which the recording paper P is fed out) of the other end surface 61a. It is fitted in a state of being press-fitted into an engagement recess 65A formed at a position facing in the circumferential direction.
For this reason, it can endure the maximum torque from the drive part 30, and it can prevent effectively that deformation | transformation, such as the twist of the conveyance roller 15 preventing and the seam 80 opening, arises.

  In the present embodiment, one engaging portion 65 is formed on one end portion (second end portion 16 s) side of the transport roller 15. When both ends (first end 16f, second end 16s) of the transport roller 15 are provided, both ends are fixed, so that the shaft around the axis acting on the transport roller 15 by continuous driving or the like is used. When the rotational torque is increased, the twist acting on the transport roller 15 is increased, and a large energy is accumulated due to the twist. If it becomes like this, even if it will be in the state where torque does not act, it will change without returning. The same applies to the case where a plurality of transport rollers 15 are provided in the axial direction.

  On the other hand, by providing only one engaging portion 65 on the side close to the drive portion 30 as in the present embodiment, the end portion at the seam 80 portion on the end (16A) side opposite to the drive portion 30 is provided. The stress can be released by the axial displacement of 62a and 62b (end surfaces 61a and 61b). Therefore, the deformation at this time returns to the original state in the state where the rotation torque after the rotation of the transport roller 15 is not applied, and the twist deformation does not remain in the transport roller 15.

  Further, since the engaging portion 65 needs to be formed in a region that avoids the bearing portion and the printing region, when the engaging portions 65 are provided at both ends, it is difficult to reduce the size of the transport roller 15 in the axial direction. . In the present embodiment, since the engaging portion 65 is provided only on one end side on one end side of the transport roller 15, the transport roller 15 can be shortened, and downsizing of the entire apparatus can be realized.

  Further, since the engaging protrusion 65 is press-fitted with the engaging protrusion 65B in the engaging recess 65A, the length of the seam 80 is longer than that of the conventional configuration without the engaging part 65. For this reason, if a plurality of engaging portions 65 are provided, the transport roller 15 tends to warp in the axial direction. In order to prevent such a warp of the transport roller 15 in the axial direction, a smaller number of the engaging portions 65 is suitable.

  Moreover, in this embodiment, the roller main body 16 of the conveyance roller 15 is formed of a metal plate in which winding by a steel plate coil remains, and is formed in a cylindrical shape in which a surface that is the inner peripheral side of the coil is an inner peripheral surface. ing. The winding of the metal plate by the steel plate coil is a warp such that the surface that was the inner peripheral surface of the steel plate coil becomes a concave surface. In other words, the metal plate forming the roller body 16 remains so as to warp toward the inner peripheral surface side of the roller body 16.

  Therefore, the winding does not act at least in the direction of opening the joint 80 of the roller body 16. Therefore, it is possible to make it difficult to open the seam 80 of the roller body 16 as compared with the case where the winding that warps toward the outer peripheral surface side of the roller body 16 remains. That is, according to this embodiment, even if stress is applied in the direction of opening the seam 80 of the roller body 16, it is possible to prevent the seam 80 from being opened, and the transport roller 15 capable of obtaining high transport accuracy. Can be provided.

  Moreover, the circumferential direction (bending direction) of the roller main body 16 and the winding direction (rolling direction of a metal plate) of a steel plate coil are the same. Therefore, the bending direction of the metal plate forming the roller body 16 can be matched with the direction of warping due to winding. Thereby, the winding of the metal plate forming the roller body 16 acts in the direction of closing the joint 80 of the roller body 16. Therefore, the opening of the joint 80 of the roller body 16 can be more effectively prevented.

  In addition, by adopting a hollow cylindrical shaft for the roller body 16, the weight can be greatly reduced as compared with the case where a solid shaft is used. Moreover, the request | requirement with respect to the machinability of material becomes low compared with the case where a solid axis | shaft is used for the roller main body 16. FIG. Therefore, it is possible to use a material that does not contain harmful substances such as lead as the material of the roller body 16, and the environmental load can be reduced.

  In addition, a high friction layer 50 is formed on the transport roller 15, and the driven roller 17 is disposed at a position where the driven roller 17 contacts the high friction layer 50. Therefore, the force for pinching the recording paper P between the transport roller 15 and the driven roller 17 is increased, and the transportability of the recording paper P is improved. In addition, since the high friction layer 50 is formed in the attachment region 15 </ b> C where the positioning member 14 is attached to the transport roller 15, the positioning member 14 is well fixed to the roller body 16 so that the axial direction of the transport roller 15 is increased. Misalignment is prevented. Therefore, the occurrence of gear disengagement is prevented, and the recording paper P can be conveyed with high accuracy over a long period of time with high reliability. As described above, the ink jet printer 1 according to the present embodiment can transport the recording paper P with high accuracy over a long period of time by the transport unit 20, and performs high-precision printing processing with high printing accuracy on the recording paper P. I can.

Next, the manufacturing apparatus of the conveyance roller 15 is demonstrated.
FIG. 5 is a schematic diagram of a manufacturing apparatus for the transport roller 15 of the present embodiment.
As shown in FIG. 5, the manufacturing apparatus 100 has a configuration in which an uncoiler 110, a leveler 120, a first press machine 130, and a second press machine 140 are arranged in one direction.
Further, the manufacturing apparatus 100 includes a conveyance unit (not shown) that sends the metal plate M unwound from the coil C in one direction, and a cutting unit (not shown) that cuts the processed cylindrical shaft from the metal plate M. .
The uncoiler 110 is for supporting a cylindrical coil (steel plate coil) C around which a metal plate M is wound in the rolling direction so as to be rotatable about an axis and rewinding the coil C.

  The leveler 120 includes a plurality of work rolls 121 arranged alternately above and below, and the metal plate M is flattened by passing the metal plate M between the upper and lower work rolls 121. The leveler 120 of this embodiment does not completely remove the wrapping (warping) caused by the coil C of the metal plate M, but adjusts the wrapping to such an extent that processing by the first press machine 130 is possible. .

The first press machine 130 includes a male die (punch) 131 and a female die (die) 132, and is configured to punch the metal plate M into a predetermined shape by pressing.
The second press machine 140 includes a plurality of female dies (bending dies) 141 and 143 and male dies (bending punches) 142 and 144 arranged in one direction, and an upper die 145 and a lower die 146. The plate M is configured to be bent. Then, while the metal plate M is intermittently fed in one direction by a conveyance unit (not shown), the metal plate M is gradually brought closer to the cylinder by sequentially bending with different molds (sequential feed). ing.

Next, a method for manufacturing the transport roller 15 will be described.
First, a coil C is prepared in which a metal plate M such as a cold rolled steel plate or an electrogalvanized steel plate having a thickness of about 0.8 mm to 1.2 mm is wound in the rolling direction. And the coil C is supported by the uncoiler 110 of the manufacturing apparatus 100, the coil C is rotated around an axis | shaft, and the metal plate M is rewound. The metal plate M unwound from the coil C is in a state in which an arc-like winding remains in a side view in which the inner peripheral surface C1 of the coil C is concave and the outer peripheral surface C2 is convex. . The rewound metal plate M is transported in one direction (rolling direction) by a transport unit (not shown) and reaches the leveler 120.

  The metal plate M that has reached the leveler 120 is flattened by a plurality of work rolls 121 arranged above and below, and the winding is adjusted. As a result, the metal plate M is flattened to such an extent that it can be processed by the first press machine 130, but the winding around which the inner peripheral surface C1 of the coil C becomes concave is left to some extent. The metal plate M flattened by the leveler 120 is transported in one direction by a transport unit (not shown) and reaches the first press machine 130.

  The metal plate M that has reached the first press machine 130 is punched by a press using a male die 131 and a female die 132. In this punching process, a metal plate M die-cut by the punching process as shown in FIGS. 6A and 6B is formed as a base material. At this time, the engaging concave portion 65A and the engaging convex portion 65B are formed on the long sides 60b and 60b of the flat plate portion 60, respectively.

FIG. 7 is a plan view of the metal plate M punched by the first press.
As shown in FIG. 7, the metal plate M is formed by punching a frame portion 66 continuous in the transport direction (rolling direction), a strip-shaped flat plate portion 60 extending in a direction intersecting the transport direction, and the frame portion 66. A connecting portion 67 that connects the flat plate portion 60 is formed. In the present embodiment, the flat plate portion 60 is substantially rectangular, and is stamped such that the short side 60a is parallel to the rolling direction and the long side 60b is orthogonal to the rolling direction. As described above, the engaging recess 65A and the engaging protrusion 65B are formed on the long sides 60b and 60b side. By repeatedly pressing the metal plate M while being transported intermittently by a transport unit (not shown), a plurality of flat plate portions 60 and connecting portions 67 are formed at equal intervals in the transport direction of the metal plate M.

  The metal plate M punched by the first press machine 130 is conveyed by a conveyance unit (not shown) and reaches the second press machine 140 shown in FIG.

  And the metal plate M which is a base material of the roller main body 16 is bent into a cylindrical shape whose upper surface C2 shown in FIG.

  FIG. 8A to FIG. 8C and FIG. 9A to FIG. 9C are side views showing a bending process by the second press machine. The flat plate portion 60 of the metal plate M that has reached the second press machine 140 is bent by a press in a direction (rolling direction) parallel to the short side 60a shown in FIG. That is, bending is performed so that a pair of end faces along the long sides 60b and 60b on both sides of the flat plate portion 60 are brought close to each other. Then, as shown in FIG. 8A to FIG. 8C and FIG. 9A to FIG. 9C, the pair of end faces are formed in a cylindrical shape so as to face each other.

  Specifically, first, the flat plate portion 60 of the metal plate M is pressed with a female die (bending die) 141 and a male die (bending punch) 142 shown in FIG. 62b is bent into an arc shape (preferably approximately ¼ arc). In FIG. 8A, these members are shown with a space between the flat plate portion 60, the female die 141, and the male die 142 for easy understanding of each member. In reality, it does not exist, and the flat plate portion 60, the female die 141, and the male die 142 are in close contact with each other at their contact portions. The same applies to FIGS. 8B, 8C, and 9A to 9C described later.

  Here, the male mold 142 is disposed so as to face the surface C1 (the lower surface of the flat plate portion 60 in FIG. 8) which is the inner peripheral side in the coil C shown in FIG. Further, the female die 141 is disposed so as to face the surface C2 (the upper surface of the flat plate portion 60 in FIG. 8) which is the outer peripheral side in the coil C shown in FIG. Thus, both end portions 62a and 62b of the flat plate portion 60 are bent to the surface C1 side which is the inner peripheral surface of the coil C.

  Next, after feeding the metal plate M in one direction, the second female die (bending die) 143 and the second male die (bending punch) 144 shown in FIG. The center part in the side direction (bending direction) is pressed. Then, the flat plate portion 60 is bent into an arc shape (preferably approximately ¼ arc) on the surface C1 side which is the inner peripheral side in the coil C shown in FIG.

  Next, after feeding the metal plate M in one direction, the core die 147 is disposed inside the flat plate portion 60 as shown in FIG. Then, using the upper mold 145 and the lower mold 146 shown in FIG. 8C, as shown in FIGS. 9A to 9C, the end faces 61a of the both end portions 62a and 62b of the flat plate portion 60 are used. , 61b are brought close to each other.

  Here, the outer diameter of the core die 147 shown in FIGS. 8C and 9A to 9C is equal to the inner diameter of the hollow cylindrical roller body 16 to be formed. Further, as shown in FIG. 8C, the radius of the press surface 146c of the lower die 146 and the radius of the press surface 145a of the upper die 145 are respectively equal to the radius of the outer diameter of the roller body 16 considering the grinding allowance. It is. Further, as shown in FIGS. 9A to 9C, the lower mold 146 is a pair of left and right split molds, and the split molds 146a and 146b are configured to be able to move up and down independently.

That is, from the state shown in FIG. 8 (c), as shown in FIG. 9 (a), the left split mold 146a is brought close to the upper mold 145, and one side of the flat plate portion 60 is pressed to form a substantially semicircular shape. Bend to.
The upper mold 145 is also a pair of left and right split molds (refer to the split surface 145b) like the lower mold 146, and the upper mold on the same side is brought close to the split mold 146a in the process shown in FIG. 9A. Also good.

  Next, as shown in FIG. 9B, the core die 147 is moved to the upper die 145 side slightly (so that the end surface 61a on one side and the end surface 61b on the other side can be brought close to each other) The split mold 146b on the other side is brought close to the upper mold 145, and the other side of the flat plate portion 60 is pressed and bent into a substantially semicircular shape.

Thereafter, as shown in FIG. 9C, the core mold 147 and the pair of split molds 146a and 146b are both brought close to the upper mold 145 to form a cylindrical roller body (hollow pipe) 16. In this state, the end surfaces 61a and 61b on both the left and right sides are in a state of facing each other.
That is, in this cylindrical roller body 16, the end surfaces 61a and 61b on both sides of the flat plate portion 60 of the metal plate M as a base material are close to each other, and a seam is formed between these end surfaces 61a and 61b. ing. Here, the surface C <b> 1 that was the inner peripheral side of the coil C shown in FIG. 5 is the inner peripheral surface of the roller main body 16, and C <b> 2 that was the outer peripheral side surface of the coil C is the outer peripheral surface of the roller main body 16. . Thus, the roller body 16 is formed so that the flat plate portion 60 is wound around the core die 147.

FIG. 10 shows a metal plate M in which the flat plate portion 60 is formed into a cylindrical shape in stages through the steps shown in FIGS. 8A to 8C and FIGS. 9A to 9C. It is a top view.
The metal plate M punched out as shown in FIG. 7 arrives at the second press machine 140 shown in FIG. 5 and is intermittently sent in one direction, while FIGS. 8 (a) to 8 (c), The flat plate portion 60 is sequentially bent by a press through the steps shown in FIGS. 9A to 9C (a progressive press). Therefore, as shown in FIG. 10, the flat plate portion 60 that has reached the second press machine 140 becomes closer to a cylinder toward the front in the conveying direction of the metal plate M. After the flat plate portion 60 is formed in a cylindrical shape, the connecting portion 67 is cut by a cutting portion (not shown) to form a hollow cylindrical roller body 16.

In the present embodiment, when the roller main body 16 having the seam 80 (see FIG. 9C, etc.) is formed by abutting the pair of end surfaces 61a, 61b (FIG. 7) of the metal plate M, the engagement recess 65A is engaged. The end faces 61a and 61b are brought into contact with each other so as to press-fit the mating convex portion 65B, thereby forming a hook-shaped seam 80.
Thereby, it is possible to prevent deformation such as opening of the joint 80 due to torque at the time of rotational driving. Moreover, since the engaging convex part 65B protrudes toward the normal rotation direction of the conveying roller 15, the effect of preventing twisting with respect to the rotational torque of the conveying roller 15 having a large load is high.

  Further, even when a sag sd, a shear surface sp, a fracture surface bs, and a burr (not shown) are formed on the metal plate M that has been die-cut as shown in FIG. The upper surface C2 on which the sagging sd is formed is preferably on the outer peripheral side of the roller body 16. In other words, it is preferable that the lower surface C <b> 1 of the metal plate M continuing to the burr and the fracture surface bs is on the inner peripheral side of the roller body 16.

  Thereby, when forming the roller main body 16 which has the joint 80 (refer FIG.9 (c) etc.) by abutting a pair of end surface 61a, 61b of the metal plate M, the burr | flash and the unevenness | corrugation of the torn surface bs become obstacles. The seam 80 can be prevented from opening.

  Next, in this embodiment, the process (stress adjustment process) which adjusts the stress which remains in the formed roller main body 16 is performed. In this stress adjustment step, a pressing force is applied to at least a predetermined portion of the outer peripheral surface 16a of the roller body 16 where the high friction layer 50 is formed. In the present embodiment, a case where a pressing force is applied to almost the entire outer peripheral surface 16a of the roller body 16 will be described as an example. In the stress adjustment step, a pressing force can be applied to the roller body 16 using at least one of the following three steps.

(1) Roll leveler process In a roll leveler process, a plurality of press rollers are used. Here, as shown in FIG. 11A, a case where two pressing rollers R1 and R2 are used will be described as an example. The pressing roller R1 has a convex outer peripheral surface. The pressing roller R2 has a concave outer peripheral surface.

  First, the roller body 16 is clamped by the pressing rollers R1 and R2. After sandwiching the roller body 16, the pressing rollers R1 and R2 are rotated while pressing the roller body 16 with the two pressing rollers R1 and R2. In this state, the roller body 16 and the pressing rollers R <b> 1 and R <b> 2 are relatively moved in the direction of the central axis of the roller body 16.

  The positions of the pressing rollers R1 and R2 are fixed, and the roller body 16 passes between the pressing roller R1 and the pressing roller R2. Thereby, a pressing force is applied to the roller body 16 in order from the first end portion 16f to the second end portion 16s. The stress remaining in the roller body 16 is adjusted by this pressing force.

(2) Rolling process Next, the case where a rolling process is performed is demonstrated.
The rolling process is so-called through-feed rolling (also called step rolling or through rolling) using two rolling rollers 201 and 202.

  Specifically, as shown in FIG. 11B, the two rolling rollers 201 and 202 arranged so as to sandwich the roller body 16 are pressed against the roller body 16 with a predetermined pressure. In this state, the two rolling rollers 201 and 202 are rotated in the same direction. In through-feed rolling, the rolling rollers 201 and 202 rotate, so that the roller body 16 moves in the axial direction H while rotating in the direction opposite to the rotating direction of the rolling rollers 201 and 202.

  In order to form the high friction layer 50 on the surface of the rolling rollers 201 and 202, spiral recesses 201a and 202a are formed, and the recesses 201a and 202a deform the surface of the roller body 16, On the surface of the roller body 16, a lattice-shaped uneven portion 203 is formed.

  Thus, the uneven part 203 is formed in order from the first end part 16f of the roller body 16 to the second end part 16s. By forming the uneven portion 203, the stress remaining in the roller body 16 is adjusted. In addition, about the depth (unevenness | corrugation level | step difference) of the said uneven | corrugated | grooved part 203, it can set suitably in the range of 5 micrometers-50 micrometers.

  In the rolling step, a pressing force is applied to the entire roller body 16 by making the axial dimension of the rolling rollers 201 and 202 equal to the axial dimension of the roller body 16. Even in this case, the stress remaining in the roller body 16 is adjusted.

(3) Rotation pressing process Next, the case where a rotation pressing process is performed is demonstrated.
The rotation pressing step is a step of rotating the roller body 16 in a state where the pressing member is pressed against the roller body 16 and relatively moving the pressing member and the roller body 16 in the central axis direction of the roller body 16.

  An example of the rotation pressing step is an example in which the roller body 16 is moved as shown in FIG. In this case, the pressing members R3 and R4 are fixed on the table TBL. The distance between the pressing member R3 and the pressing member R4 is set to be slightly smaller than the diameter of the roller body 16.

  In this state, the roller body 16 is passed between the pressing member R3 and the pressing member R4 while rotating the roller body 16. The pressing member R <b> 3 and the pressing member R <b> 4 press the roller body 16 so as to be sandwiched. For this reason, a pressing force is applied from the first end portion 16f of the roller body 16 to the second end portion 16s. By this pressing force, the stress remaining in the roller body 16 is adjusted.

  Moreover, as a rotation press process, as shown in FIG.11 (d), the example which moves the press member R5 without moving the roller main body 16 is mentioned. In this case, the roller body 16 is rotated around the central axis while the position of the roller body 16 is fixed. In this state, the pressing member R5 is pressed against the roller body 16, and the pressing member R5 is moved along the central axis of the roller body 16.

  For this reason, a pressing force is applied from the first end portion 16f of the roller body 16 to the second end portion 16s. By this pressing force, the stress remaining in the roller body 16 is adjusted. In addition, it is preferable that the front-end | tip (part which contact | abuts the roller main body 16) of pressing member R5 is formed in the roller shape.

  In addition, when performing each process of said (1)-(3), you may make it apply pressing force to the said roller main body 16 in the state which inserted the core member (not shown) inside the roller main body 16. FIG. Absent. Thereby, it can avoid that the roller main body 16 deform | transforms with a pressing force.

  Next, in this embodiment, centerless polishing is performed in order to increase the roundness of the formed roller body 16 and reduce the runout. In this polishing step, as shown in FIG. 12C, the outer peripheral surface 16a of the roller body 16 is polished using a grindstone member GD formed in a columnar shape (or a cylindrical shape). In the polishing step, a portion having a predetermined depth (thickness of about 30 μm to 80 μm, hereinafter referred to as “polishing depth”) is polished from the surface of the roller body 16.

  The roller main body 16 is arranged between two grindstone members GD arranged with an interval smaller than the outer diameter of the roller main body 16 so that the roller main body 16 is in contact with the outer peripheral portions of the two grindstone members GD. . Thereafter, the two grindstone members GD are rotated in the same direction. A frictional force is generated between each grindstone member GD and the roller body 16 by the rotation of the two grindstone members GD.

  The two grindstone members GD are formed so that the dimension in the longitudinal direction (the height direction of the cylinder) is larger than that of the roller body 16 so that the entire longitudinal direction of the roller body 16 can be polished at a time. It is preferable to use one. Further, when the grindstone member GD is rotated, in order to ensure a margin in the longitudinal direction of the roller main body 16, the roller main body is arranged at the center in the longitudinal direction of the grindstone member GD so that the entire longitudinal direction is in contact with the two grindstone members GD. 16 is preferably arranged.

  The outer peripheral surface 16a of the roller main body 16 is polished while the roller main body 16 rotates in a direction opposite to the rotation direction of the grindstone member GD by the frictional force generated by the rotation of the grindstone member GD. For this reason, almost the entire outer peripheral surface 16a of the roller body 16 is uniformly polished, and the roundness of the roller body 16 becomes better than before the polishing step.

  When the rolling process is performed in the stress adjustment process, the uneven portion 203 formed on the outer peripheral surface 16a of the roller body 16 is removed by polishing. Based on this, when the rolling process is performed, the uneven part 203 is formed so that the portion of the roller body 16 where the high friction layer 50 is formed is deeper than the polishing depth in the polishing process. . Further, the uneven portion 203 is formed so that the portion where the high friction layer 50 is not formed is shallower than the polishing depth.

  If a grinding | polishing process is performed in this state, the part in which the high friction layer 50 is formed among the roller main bodies 16 will be in the state in which a part of uneven | corrugated | grooved part 203 remained. Moreover, the uneven | corrugated | grooved part 203 will be in the state from which the high friction layer 50 part of the roller main body 16 is not formed. Therefore, in the process of forming the high friction layer 50, since the uneven portion 203 can be used, the manufacturing efficiency is increased.

  After performing the polishing step, the roller body 16 having a high roundness and a small deflection amount is obtained. In the roller body 16, the gap 80 between the both end faces 61a and 61b is further narrowed, so that the gap 80 between the both end faces 61a and 61b is narrowed as shown in FIG. Is formed.

  In the pressing process and polishing step, it is preferable that the gap between the both end faces 61a and 61b of the flat plate portion 60 is eliminated, that is, the both end faces 61a and 61b are in contact with each other. However, it is difficult to completely eliminate the gap while improving the roundness and the amount of deflection of the roller body 16 to be obtained, and a certain amount of gap is formed at present.

  The seam 80 has the same dimension (width) on the outer peripheral surface and the inner peripheral surface of the flat plate portion 60, so that the distance between the pair of end surfaces 61a and 61b is a roller as shown in FIG. The main body 16 is relatively wide on the outer peripheral surface 16a side and relatively narrow on the inner peripheral surface 16b side.

  When the roller body 16 serving as the cylindrical shaft according to the present invention is thus formed, a high friction layer 50 as shown in FIGS. 3 and 4 is formed on the surface of the roller body 16.

  As a method for forming the high friction layer 50, a dry method and a wet method (or a method using both of them) can be employed. In this embodiment, the dry method is preferably employed. Specifically, first, resin particles and inorganic particles are prepared as a material for forming the high friction layer 50. As the resin particles, fine particles having a diameter of about 10 μm made of an epoxy resin or a polyester resin are preferably used. In addition, as the inorganic particles, alumina whose particle diameter is in the range of 15 μm or more and 90 μm or less as described above and whose weighted average particle diameter (average particle diameter) serving as the center diameter is 45 μm is adjusted. Particles are preferably used.

  As the alumina particles, those adjusted to a predetermined particle size distribution by crushing treatment are used. By being produced by crushing treatment, the alumina particles have a sharp end with a relatively sharp end, and the sharp end has a high frictional force.

That is, in the present invention, alumina particles (inorganic particles) having an average particle diameter (center diameter) larger than the distance d1 (30 μm) on the outer peripheral surface side of the seam 80 are used.
In particular, the particle size distribution (particle size range) includes particles that are smaller than the distance d1 on the outer peripheral surface side of the joint 80 and larger than the distance d2 (10 μm) on the inner peripheral surface side. Is preferred. Further, the minimum particle size in the particle size distribution is preferably larger than the shortest distance between the pair of end surfaces 61a and 61b in the joint 80 and the distance d2 on the inner peripheral surface side.

  When such resin particles and inorganic particles are prepared, first, the above-described resin particles are applied to the roller body 16. That is, the roller body 16 is placed in a painting booth (not shown), and the roller body 16 is kept at a (minus) potential in a single state.

  Then, the spray particles (resin particles) are charged to a + (plus) high potential while spraying (spraying) the resin particles toward the roller body 16 using a tribogun of an electrostatic coating apparatus (not shown). Let Then, the charged resin particles are adsorbed on the outer peripheral surface of the roller body 16 to form a resin film.

  Here, the formation of the resin film by spraying the resin particles corresponds to the formation region of the high friction layer 50 shown in FIGS. 3 and 4. That is, by not masking the entire length of the roller body 16 and masking both ends thereof with a tape or the like, as shown in FIG. The resin film 51 is selectively formed only in the region corresponding to 15C. In FIG. 13A and FIGS. 13B and 13C described later, the joint 80 is not shown.

  In the resin film 51, weak static electricity of about +0.5 KV remains after spray coating. In this spray coating, the roller body 16 is rotated around its axis, so that the resin film 51 is formed with a substantially uniform thickness over the entire circumference. The resin film 51 is formed to have a thickness of about 10 μm to 30 μm in consideration of the powder diameter of the alumina particles described above. About such a film thickness, it can adjust suitably with the ejection amount, ejection time, etc. of a resin particle.

Next, the roller main body 16 on which the resin film 51 is formed is taken out from the above-described painting booth and transferred to another painting booth 90 shown in FIG. 14 by a handling robot (not shown).
The coating booth 90 is provided with a pair of rotational drive members 91 and 91 at the lower portion thereof, and the rotational drive members 91 and 91 are provided with a chuck 92 for supporting the roller body 16 substantially horizontally. ing.

  Then, both ends of the roller body 16 are held and fixed to the chucks 92 and 92, and the chucks 92 and 92 are rotated by the rotation driving member 91. As a result, the roller body 16 is slowly rotated around its axis at a low speed of about 100 rpm to 500 rpm. Of course, the roller body 16 may be supported slightly obliquely.

  Further, a corona gun 93 is disposed on the coating booth 90, and the corona gun 93 moves on the shaft 94 in the left-right direction in FIG. Further, an exhaust mechanism 90 a is provided at the bottom of the painting booth 90. As a result, a slow air flow is formed in the painting booth 90 in the downward direction. The suction air volume of the exhaust mechanism 90a is set appropriately.

  Under such a configuration, the alumina particles 95 are sprayed and sprayed from the corona gun 93 while rotating the roller body 16 about its axis, whereby the alumina particles are formed on the resin film 51 formed on the roller body 16. 95 is selectively electrostatically adsorbed. The alumina particles are selectively electrostatically adsorbed on the resin film 51 by masking both end portions of the roller body 16 with a tape or the like as in the formation of the resin film 51.

  At the time of electrostatic coating, the surface potential of the chuck 92 and the rotary drive member 91 is set to be substantially equal to the potential of the roller body 16, and the inner surface potential of the coating booth 90 is electrically neutral and substantially zero. To do. This is to prevent the alumina particles 95 from the corona gun 93 from being adsorbed to parts other than the roller body 16. In order to keep the inner surface potential of the coating booth 90 electrically neutral, it is desirable to manufacture the coating booth 90 using a steel plate having an inner surface electrical resistance of about 1011Ω.

  The electric potential applied to the corona gun 93 is set to zero V, and the pressure of the air supplied to the corona gun 93 is set to a low value of about 0.2 Mpa. Next, while the corona gun 93 is moved in the left-right direction in FIG. 14, alumina particles 95 having substantially zero potential are blown out from above, and the alumina particles 95 are naturally dropped by their own weight in the vertical direction.

  Then, as described above, since the weak static electricity (about +0.5 KV) remains in the resin film 51 of the roller body 16 by the electrostatic coating, the alumina particles 95 are resinated by this static electricity. Electrostatic adsorption is performed almost uniformly on the entire circumference of the film 51. The alumina particles 95 thus electrostatically adsorbed adhere to the outer peripheral surface of the roller body 16 using the resin film 51 as a binder in a state where the alumina particles 95 are in contact with the surface of the resin film 51 and partially enter.

  Here, in this embodiment, since the inner surface potential of the coating booth 90 is electrically neutral and substantially zero, and the air flow in the coating booth 90 is formed in a slow downward flow, the alumina particles 95 naturally falls down vertically due to its own weight. Below the dropping direction, the horizontally supported roller body 16 rotates slowly around its axis, so that the alumina particles 95 are dispersed almost uniformly on the outer peripheral surface of the roller body 16.

  By the way, in this embodiment, the content rate of the alumina particles 95 in the high friction layer 50 in the attachment region 15C is set lower than the content rate in the printing region 15A. Therefore, a cover member 101 that covers an area corresponding to the attachment area 15 </ b> C is provided in the painting booth 90. An opening 101 a is formed in the cover member 101, and a part of the coated alumina particles 95 can be selectively transmitted by being shielded. By using such a cover member 101, the adhesion rate of the alumina particles 95 in the attachment region 15C can be controlled.

  Therefore, the alumina particles 95 that are densely attached are exposed particularly on the surface of the resin film 51 corresponding to the printing region 15 </ b> A not covered with the masking and cover member 101. On the other hand, the alumina particles 95 attached in an appropriately dispersed state are exposed on the surface of the resin film 51 corresponding to the attachment region 15 </ b> C covered with the cover member 101. That is, when the alumina particles 95 come into contact with the resin film 51 by electrostatic attraction, a part of the alumina particles 95 enters the resin film 51 and the remaining part protrudes from the surface of the resin film 51. At that time, since the alumina particles 95 are likely to stand vertically to the surface of the roller body 16, the alumina particles 95 are uniformly distributed, and most of them are sharply pointed (top) facing outward. Adhere to.

  Therefore, the alumina particles 95 exhibit a high frictional force due to the end portion protruding from the surface of the resin film 51. Here, in order for the alumina particles 95 to exhibit a necessary and sufficient frictional force against the recording paper P, the area occupied by the alumina particles 95 is 20% to 80% with respect to the area of the resin film 51. It is preferable to do this. In the present embodiment, in the printing region 15A, the area occupied by the alumina particles 95 is set to 80% with respect to the area of the resin film 51, and in the attachment region 15C, the alumina particles 95 are included in the area of the resin film 51. The occupied area was set to 20%.

  In this way, when the positioning member 14 is attached to the attachment region 15C in a later step, it is possible to prevent the occurrence of a problem such that the frictional force between the roller body 16 and the positioning member 14 becomes too large in the attachment region 15C. . Therefore, it can prevent that the assembly property at the time of inserting the positioning member 14 in the roller main body 16 falls.

  The application (spreading) of the alumina particles 95 is not limited to the application by the electrostatic coating method as long as the alumina particles 95 are slowly sprayed downward in the vertical direction, and a spray gun is used. The application (spreading) method may be used.

  Further, the cover member 100 is not limited to the one having the opening 100a as described above. For example, the alumina particles 95 are selected through a gap formed between the roller body 16 and the cover member by disposing the cover member having no opening in a state separated from the roller body 16 (part corresponding to the attachment region 15C). However, it may be configured to adhere. In this configuration, the adhesion rate of the alumina particles 95 in the attachment region 15C can be controlled by adjusting the size of the gap.

  After the alumina particles 95 are spread and adhered on the resin film 51 in this way, the roller body 16 is heated at a temperature of about 180 ° C. to 300 ° C. for about 20 minutes to 30 minutes, and the resin film 51 is baked and cured. . As a result, the alumina particles 95 are fixed to the roller body 16. Thus, as shown in FIG. 13 (c), the high friction layer 50 in which the alumina particles (inorganic particles) 95 are dispersed and exposed in the resin film 51 is formed in the printing region 15A and the attachment region 15C. The conveyance roller 15 is obtained.

  In the present embodiment, the application (spraying) of the resin particles and the application (spraying) of the alumina particles (inorganic particles) are performed in different painting booths. However, it may be performed in the same painting booth. It is.

  When the high friction layer 50 is formed in this manner, the gap between the end faces 61a and 61b is mainly formed in the joint 80, without forming a groove due to the gap between the end faces 61a and 61b of the flat plate portion 60. Embedded with alumina particles 95.

  That is, since alumina particles 95 having an average particle diameter larger than the distance d1 on the outer peripheral surface side of the seam 80 are used, most of the alumina particles 95 do not enter the seam 80. As shown in FIG. 15, it adheres to the outer peripheral surface of the roller body 16 via a resin film 51. Therefore, although the gap is formed between the end surfaces 61a and 61b of the flat plate portion 60 in the joint 80, the alumina particles 95 cover the gap, so that a groove due to the gap is substantially formed. It will not be done.

  Further, the alumina particle 95 has a particle size distribution (particle size) including particles 95a that are smaller than the distance d1 (30 μm) on the outer peripheral surface side of the joint 80 and larger than the distance d2 (10 μm) on the inner peripheral surface side. Since the particles 95a enter the gap formed in the joint 80 and stay there, the groove due to the joint 80 is not reliably formed.

  In addition, even when a force is applied to the roller body 16 (conveying roller 15) in the direction of narrowing the gap during use, the alumina particles 95a that enter here resists this force, so the roller body 16 (conveying roller 15). The deformation of is suppressed. Therefore, in the transport roller mechanism 19 including the transport roller 15, transport unevenness due to deformation of the transport roller 15 is prevented.

Furthermore, since the minimum particle size in the particle size distribution of the alumina particles 95 is larger than the shortest distance between the pair of end surfaces 61a and 61b in the joint 80, that is, the distance d2 on the inner peripheral surface side. When the high friction layer 50 is formed by arranging the alumina particles 95 on the surface of the roller body 16, the alumina particles 95 do not enter the roller body 16 through the gap formed in the joint 80. Therefore, after that, processing such as cleaning the inside of the roller body 16 is reduced, and the productivity can be improved accordingly.
Through the above steps, as shown in FIG. 15, the high friction layer 50 in which the alumina particles 95 are dispersed and exposed in the resin film 51 is formed, and the transport roller 15 of this embodiment is obtained.

  As described above, in the present embodiment, when the metal plate M is punched, the engaging concave portions 65A and the engaging convex portions 65B are formed on both sides in the short side direction of the flat plate portion 60, and the roller body 16 is bent. When forming, the engagement concave portions 65A and the engagement convex portions 65B are press-fitted so that the end surfaces 61a and 61b are brought into contact with each other to form a hook-shaped seam 80. Thereby, the deformation | transformation which the seam 80 opens is prevented, and it becomes possible to maintain high conveyance accuracy for a long period of time.

  In addition, after the roller body 16 is formed by bending, a pressing force is applied to a predetermined portion (the printing region 15A and the attachment region 15C) where at least the high friction layer 50 is formed on the outer peripheral surface 16a of the roller body 16. Since the residual stress in the main body 16 is adjusted, the residual stress is made uniform at least in the predetermined portion. For this reason, the shape change of the roller main body 16 in the predetermined portion can be suppressed. Thereby, the conveyance roller 15 of the stable shape can be manufactured.

  Further, according to the present embodiment, in the stress adjustment step, the pressing force is applied to the entire outer peripheral surface 16a of the roller body 16, so that the residual stress on the entire surface of the roller body 16 is adjusted uniformly. become. Thereby, the shape of the conveyance roller 15 whole can be stabilized.

  Further, in the stress adjustment step, the pressing force is sequentially applied from the first end portion 16f to the second end portion 16s of the roller body 16, and therefore the step can be performed without necessarily using a large apparatus. it can. Further, in the stress adjustment step, when the pressing force is applied in a state where the core member is inserted into the roller body 16, the deformation of the roller body 16 can be suppressed.

  The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.

  In the above-described embodiment, the configuration in which only one attachment region 15C is provided on the one end portion 16B side of the roller body 16 has been described. However, when the roller body 16 is displaced on the drive unit 30 side and the opposite side thereof, The attachment region 15C can also be provided in the vicinity of the support region 15B opposite to the drive unit 30. According to this configuration, since the positions of both end portions 16A and 16B in the roller body 16 are fixed by the positioning member 14, a highly reliable transport operation can be performed.

  Moreover, in the said embodiment, although the roller main body 16 was set as the structure currently formed as the base material the steel plate coil by which metal plates, such as a galvanized steel plate and a stainless steel plate, were wound, it is not restricted to this. . The roller body 16 may be formed by using a flat metal plate as a base material, forming a metal plate having substantially the same shape and dimensions as the flat plate portion 60 from the flat metal plate, and processing the metal plate. Absent. Therefore, in the above description or the following description, the present invention can be applied even when the flat plate portion 60 is replaced with the metal plate.

Further, an opening 170 may be provided in a part of the seam 80 formed in the roller body 16 as shown in FIG.
As shown in FIG. 16B, the seam 80 formed on the roller body 16 has a groove shape in which the inner peripheral sides of the pair of end surfaces 61a and 61b are in close contact with each other and the outer peripheral sides are separated from each other. Alternatively, the seam 80 may be formed as a gap with the pair of end surfaces 61a and 61b not contacting each other and the end surfaces 61a and 61b being slightly separated. Since the seam 80 is formed over the entire length of the transport roller 15, when the grease L supplied to the bearings 26A and 26B adheres to the surface of the transport roller 15, the grease L flows along the seam 80 by capillary action. become. In particular, as the joint 80 (the maximum distance d1 between the end surfaces 61a and 61b) is reduced in order to improve the strength of the transport roller 15, the capillary phenomenon of the grease L becomes stronger and the grease L tends to flow along the joint 80. .

  Therefore, as shown in FIG. 16C, an opening 170 is provided in a part of the seam 80 formed in the roller main body 16. As shown in FIG. 16C, the opening 170 is formed by notches 176 and 177 provided in a pair of end surfaces 61a and 61b forming the joint 80, respectively. When the end faces 61a and 61b are brought into contact with each other, the maximum distance d2 between the notches 176 and 177 is set to be about 1 mm or more, and functions as the opening 170.

  The opening 170 includes a region where the high friction layer 50 is formed (printing region 15A) and a region (supported by the bearings 26A and 26B) of the joint 80 formed over the entire length of the transport roller 15 (roller body 16) ( It is provided in a region excluding the support regions 15B and 15B). That is, the high friction layer 50 is formed in the substantially central portion of the transport roller 15, and both ends of the transport roller 15 are supported by the bearings 26 </ b> A and 26 </ b> B, so that the transport roller 15 is provided with at least two openings 170.

  The opening 170 is provided for the purpose of preventing the grease L (lubricating oil) supplied (applied) to the bearings 26A and 26B from reaching the high friction layer 50 along the joint 80 (the gap between the end surfaces 61a and 61b). That is, by providing the opening 170 in a part of the joint 80, the capillary phenomenon of the grease L is stopped. Specifically, by providing an opening 170 between the region of the joint 80 that is supported by the bearings 26A and 26B (support regions 15B and 15B) and the region where the high friction layer 50 is formed (print region 15A). The grease L is prevented from reaching the high friction layer 50. And the capillary phenomenon of the grease L can be stopped reliably by adjusting the size of the opening 170 (the maximum distance d2 between the pair of notches 176 and 177).

  Note that the present invention is not limited to the case where the notches 176 and 177 for forming the opening 170 are formed in each of the pair of end surfaces 61a and 61b forming the joint 80. That is, as shown in FIG. 16D, a notch 178 is formed only in one (end surface 61a) of the pair of end surfaces 61a and 61b forming the joint 80, and the opening 170 is formed by the notch 178 and the end surface 61b. May be formed. The shape of the opening 170 is not limited to a rectangle, and may be a circle or the like.

  Further, the shape of the seam 80 formed in the roller body 16 may be a shape as shown in FIG. That is, in the seam 80, the first end surface 274 and the second end surface 275 are in contact with each other on the outer peripheral surface 271 a side of the roller body 271. The gap between the first end surface 274 and the second end surface 275 becomes gradually wider from the radially outer side toward the inner side.

  The first angle α formed by the first end surface 274 and the outer peripheral surface 271a and the second angle β formed by the second end surface 275 and the outer peripheral surface 271a are both smaller than 90 °. .

  The first end surface 274 and the second end surface 275 of the joint 80 are in contact with each other on the outer peripheral surface 271a side, and the smoothness on the outer peripheral surface 271a side is improved in the connecting portion 276. Therefore, even if the transport roller 15 rotates, the outer peripheral surface can stably contact the recording paper P. For this reason, the recording paper P can be conveyed with high accuracy.

  As shown in FIG. 17B, the shape of the seam 80 is such that the first angle α formed by the first end surface 274 and the outer peripheral surface 271a of the seam 80 is smaller than 90 °, and the second end surface 275 The second angle β formed with the outer peripheral surface 271a may be formed with a size of 90 ° or more. In other words, the first end surface 274 and the second end surface 275 in the connection portion 276 may have a shape inclined in a predetermined direction with respect to the circumferential direction.

  The shape of the seam 80 is formed through the following steps. That is, after the metal plate 270 is formed by punching in the progressive press processing, end surface adjustment processing is performed on the first end surface 274 and the second end surface 275 of the metal plate 270, and the first end surface 274 and the second end surface are processed. The inclination of 275 with respect to the outer peripheral surface 271a is adjusted.

  As shown in FIG. 17C, the inclination of the first end surface 274 and the second end surface 275 with respect to the outer peripheral surface 271a is adjusted by pressing. By this adjustment, the first angle α formed by the first end surface 274 and the outer peripheral surface 271a and the second angle β formed by the second end surface 275 and the outer peripheral surface 271a are both smaller than 90 °.

  Accordingly, when the cylindrical roller body 271 is formed by bending the metal plate 270, the first end surface 274 and the second end surface 275 are in contact with each other at least on the outer peripheral surface 271a side.

  As shown in FIGS. 18 (a) and 18 (b), the opposed positions of the portion for fixing the positioning member 14 in the attachment region 15C of the roller body 16 made of a cylindrical pipe (hollow pipe), that is, the roller body 16 Through-holes 71a and 71a can be formed on two formation surfaces that define the diameter of each, and an engagement hole (opening) 71 including the pair of through-holes 71a and 71a can be formed. Further, a protrusion 14 b that fits into the engagement hole 71 is formed on the inner peripheral surface of the positioning member 14. According to this configuration, the positioning member 14 can be satisfactorily fixed at a predetermined position with respect to the roller body 16 by fitting the protrusion 14 b into the engagement hole 71. Further, since the positioning member 14 is engaged with the protrusion 14b and the engagement hole 71 in addition to the above-described high friction layer 50, the roller main body 16 is less likely to be displaced in the axial direction of the roller. . Therefore, good paper feeding accuracy can be obtained over a long period of time.

  As described above, the preferred embodiments according to the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the examples. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

DESCRIPTION OF SYMBOLS 15 ... Conveyance roller, 15A ... Printing area | region, 15C ... Mounting area | region, 16 ... Roller main body, 50 ... High friction layer, 71 ... Engagement hole (opening) 80 ... Seam, 95a ... Alumina particle, 101 ... Cover member, 270 ... Metal plate

Claims (6)

A printing region is formed in a cylindrical shape so that a pair of opposed end faces of the metal plate are close to or in contact with each other, the pair of end faces has a seam extending in the axial direction, and a surface of the roller body has a high friction layer. A formed transport roller,
The conveying roller, wherein the high friction layer is applied to an attachment region to which a positioning member for a bearing on the drive unit side of the roller body is attached.   The conveyance roller according to claim 1, wherein the positioning member is attached by being inserted into a roller body.   The conveyance roller according to claim 1, wherein an opening for fitting a protrusion provided on the positioning member is formed in the attachment region.   The transport roller according to any one of claims 1 to 3, wherein the high friction layer contains inorganic particles, and the inorganic particles are made of aluminum oxide.   The conveyance roller according to claim 4, wherein the content of the inorganic particles in the high friction layer in the attachment region is set lower than the content in the high friction layer in the printing region.   A printing apparatus comprising the transport roller according to claim 1.

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