JP2011098366A - Method of manufacturing conveying roller, conveying unit and printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing conveying rollers with which the deterioration of conveyance properties is suppressed. <P>SOLUTION: The method of manufacturing the conveying rollers 31 for conveying recording media includes: a first step where a nearly cylindrical member 16 is formed by bending a plate and also positioning parts 73 having a notch shape in the end parts of the cylindrical member are formed; and a second step where an axial bend which is generated on the cylindrical member in the first step is straightened by imparting bending load to the predetermined places of the cylindrical member in the state where the cylindrical member is supported on the center sides of the positioning parts in the length direction of the cylindrical member. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a transport roller manufacturing method, a transport unit, and a printing apparatus.

2. Description of the Related Art Conventionally, a printing apparatus that records information on a sheet-like recording medium has been used, and this printing apparatus is provided with a conveyance unit that conveys the recording medium. The transport unit includes a transport roller that transports the recording medium by rotating.
The transport roller is provided with a drive member such as a gear for rotating the transport roller or driving another device by the rotation of the transport roller.

  Conventionally, a solid bar-like member is generally used for the transport roller. However, since a solid material has a problem of increasing weight and cost, Patent Document 1 discloses that a metal plate is bent. A technique for forming into a cylindrical shape is described.

JP 2006-289596 A

However, the following problems exist in the conventional technology as described above.
When a metal plate is bent into a cylindrical shape, a tensile force acts on the outer peripheral surface side of the neutral surface, but due to the presence of the joint, the position on the opposite side to the joint (the center of the axis is the circumferential direction). The force in the direction of contraction centering on the position (opposite the opposite side) acts, and the force in the direction of contraction about the center part also acts in the length direction. As a result, the warp occurs in the transport roller so that the joint is directed outward and bulges out at the center in the length direction. For this reason, when the conveyance roller is supported at both ends, vibrations occur and the concentricity is lowered, which may adversely affect the conveyance characteristics in a conveyance roller that requires very high accuracy.

  SUMMARY An advantage of some aspects of the invention is that it provides a method of manufacturing a transport roller, a transport unit, and a printing apparatus that can suppress a decrease in transport characteristics.

In order to achieve the above object, the present invention employs the following configuration.
The method for manufacturing a transport roller of the present invention is a method for manufacturing a transport roller for transporting a recording medium, wherein a plate member is bent to form a substantially cylindrical cylindrical member, and a notch shape is formed at an end of the cylindrical member. A first step of forming a positioning part, and applying a bending load to a predetermined portion of the cylindrical member in a state where the cylindrical member is supported on the center side of the positioning part in the longitudinal direction of the cylindrical member, And a second step of correcting the axial bending generated in the cylindrical member in the first step.

  Therefore, in the manufacturing method of the transport roller of the present invention, the warpage and the bending generated when the plate member is bent to form the cylindrical member can be corrected by applying a bending load to a predetermined portion of the cylindrical member. It becomes possible to make it small, and the fall of a conveyance characteristic can be suppressed. In particular, in the present invention, since the cylindrical member is supported on the center side with respect to the positioning portion at the end portion where large stress tends to remain at the time of formation, a bending load can be applied to the cylindrical member with high accuracy.

In the present invention, it is preferable that the cylindrical member is supported at a position other than the conveyance area where the cylindrical member contacts and conveys the recording medium.
Thereby, in this invention, it can prevent that the conveyance characteristic with respect to a recording medium falls by the press mark etc. which arose in the conveyance area | region with the load added in a support part when a bending load is provided to a cylindrical member.

In the present invention, it is preferable that the bending load is applied to a position other than the conveyance area where the cylindrical member contacts and conveys the recording medium.
Thereby, in this invention, it can prevent that the conveyance characteristic with respect to a recording medium falls by the press mark etc. which arose when the bending load was provided to the conveyance area | region of a cylindrical member.

In the second step of the present invention, a configuration in which the bending load is applied to a joint between a pair of end portions obtained by bending the plate material can be suitably employed.
Thereby, in this invention, when curvature (bending) generate | occur | produces in a cylindrical member so that a joint may face outward in the center part of a length direction, it becomes possible to correct a bending effectively. Become.

As said 2nd process, the bending formation process of giving the bending load to the predetermined location of the said cylindrical member, and forming the bending of the reverse direction to the direction of the axial bending produced in the said cylindrical member in the said 1st process, A procedure including a reverse load applying step of applying a bending load to a predetermined portion of the cylindrical member in a direction opposite to the direction in which the bending load is applied in the bending forming step can be suitably employed.
Thereby, in this invention, since the residual stress at the time of forming a cylindrical member can once be relieved, compared with the case where a bending load is provided only to one direction, it becomes possible to make the curvature after correction small.

As the predetermined location of the cylindrical member in the above invention, between the plurality of first pressing positions arranged at intervals in the length direction of the cylindrical member and the plurality of first pressing positions in the length direction. A configuration including a plurality of second pressing positions that are positioned and face the first pressing position in the radial direction of the cylindrical member can also be suitably employed.
Thereby, in this invention, since the press position with respect to a cylindrical member increases, finer correction | amendment is attained and the deflection amount of a cylindrical member can be made still smaller.

Further, in the present invention, in the first step, the plate member is bent using a press die to form the cylindrical member, and in the second step, the shaft member is provided so as to freely advance and retract. A configuration in which a bending load is applied to a predetermined portion of the cylindrical member can also be suitably employed.
Thereby, in this invention, it becomes unnecessary to provide the apparatus which gives a bending load separately, or to transfer a cylindrical member to the apparatus which gives this load, and it can contribute to the improvement of productivity, size reduction, and cost reduction of an apparatus. .

Moreover, in this invention, the procedure which has the 3rd process which grind | polishes the surface of the said cylindrical member after the said 2nd process can also be employ | adopted suitably.
Thereby, in the present invention, it is possible to reduce the shake remaining even after the second step, and the shake amount of the cylindrical member can be further reduced.

And the conveyance unit of this invention was equipped with the conveyance roller manufactured by the manufacturing method as described previously, It is characterized by the above-mentioned.
Moreover, the printing apparatus of the present invention is characterized by including a transport roller manufactured by the manufacturing method described above.
Thereby, in this invention, since the conveyance roller with small shake amount is provided, the conveyance unit and printing apparatus which have a high conveyance characteristic can be obtained.

1 is a side sectional view of a printer according to the present invention. 4A and 4B are schematic diagrams illustrating configurations of a conveyance unit 3 and a paper discharge unit 4, in which FIG. 5A is a plan view, and FIG. It is a schematic block diagram of a conveyance roller mechanism. It is an external appearance perspective view of a roller main body. It is a top view which shows the metal plate as a base material of a roller main body. (A) is a principal part perspective view of a roller main body, (b) is a principal part sectional side view. (A)-(c) is process drawing for demonstrating the press work of a metal plate. (A)-(c) is process drawing for demonstrating the press work of a metal plate. (A)-(c) is process drawing for demonstrating the correction process of a roller main body. It is a figure for demonstrating the correction process of the roller main body of another form. It is a figure for demonstrating the correction process of the roller main body of another form. (A)-(c) is a figure for demonstrating the other shape of a joint. (A) is a principal part perspective view of a roller main body, (b) is a side view. (A) is a principal part perspective view of a roller main body, (b) is a side view. (A)-(c) is a principal part top view of the metal plate which shows an expansion | deployment engaging part. It is the principal part enlarged view of the joint of a roller main body, and its vicinity. (A) is a top view which shows a conveyance roller, (b) It is sectional drawing which shows a joint, (c) is sectional drawing which shows opening, (d) is a figure which shows the modification of opening. 3 is a schematic diagram illustrating a configuration example of a transport roller 31. FIG. 3 is a schematic diagram illustrating a configuration example of a transport roller 31. FIG. It is sectional drawing after adjusting a pair of end surface of the metal plate 60. FIG. It is process sectional drawing of the extraction process which concerns on embodiment. (A)-(c) is a principal part top view of the metal plate which shows an expansion | deployment engaging part. (A), (c) is a figure which shows a joint, (b) is a top view of a metal plate. FIG. 6 is a perspective view illustrating a relationship between a conveyance roller and a sheet during paper feeding. (A)-(c) is a figure for demonstrating the shape of a joint. (A) is shape explanatory drawing of a joint, (b) is effect | action explanatory drawing. (A)-(c) is a figure for demonstrating the shape of a joint.

Hereinafter, embodiments of a method for manufacturing a transport roller, a transport unit, and a printing apparatus according to the present invention will be described with reference to FIGS.
The following embodiment shows one aspect of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in the following drawings, in order to make each configuration easy to understand, the actual structure is different from the scale and number of each structure.

First, the configuration of a printer (printing apparatus) 1 provided with a transport roller according to the present embodiment will be described with reference to FIG.
FIG. 1 is an overall configuration diagram of a printer 1 according to the present embodiment.
The printer 1 is a printing apparatus that records information such as characters and images by ejecting ink onto paper or the like as a recording medium. The printer 1 includes a paper feed unit 2, a conveyance unit (conveyance unit) 3, a paper discharge unit 4, a head unit 5, and a control unit CONT.

The paper feed unit 2 holds a plurality of recording papers (recording media, sheet materials) P, which are recording media, and supplies the recording paper P toward the transport unit 3. And a paper feed roller 22.
The paper feed tray 21 holds a plurality of recording papers P, and is provided at a predetermined angle (about 45 °) with respect to a horizontal plane. As the recording paper P, a sheet-like recording medium that can be printed with ink is used, and plain paper, coated paper, an OHP (overhead projector) sheet, glossy paper, glossy film, and the like are used.

  The paper feed roller 22 is a roller that rotates to supply the recording paper P toward the transport unit 3, and is provided on the transport unit 3 side of the paper feed tray 21. A separation pad (not shown) is provided at a position facing the outer peripheral surface of the paper feed roller 22, and the separation pad and the paper feed roller 22 cooperate to convey the recording paper P one by one. Can be supplied to.

The transport unit 3 transports the recording paper P supplied from the paper feeding unit 2 toward the paper discharge unit 4 and is a place where a printing operation is performed on the recording paper P. The transport unit 3 includes a transport roller (cylindrical shaft) 31, a driven roller 32, a platen 33, a diamond rib 34, and a drive unit 6 (see FIG. 2).
The transport roller 31 is a roller for accurately transporting the recording paper P to a predetermined printing position by rotating, and extends in a horizontal plane and in a direction perpendicular to the transport direction of the recording paper P, and is substantially cylindrical. It is the cylindrical axis | shaft formed in this. The transport roller 31 is rotatably supported by a pair of substantially U-shaped bearings (not shown) provided in the transport unit 3 and is rotated by driving of the drive unit 6. Details of the transport roller 31 will be described later.

  The driven roller 32 is a substantially cylindrical member, and a plurality of the driven rollers 32 are arranged at intervals along the axial direction of the transport roller 31. The driven roller 32 is rotatably provided at a position facing a high friction layer 50 (see FIG. 3) of the transport roller 31 described later. The driven roller 32 is provided with a biasing spring (not shown), and the driven roller 32 is biased and brought into contact with the high friction layer 50 of the transport roller 31 by the biasing force of the biasing spring. For this reason, the driven roller 32 rotates following the rotation operation of the transport roller 31. Note that the outer peripheral surface of the driven roller 32 is subjected to low wear treatment such as fluororesin coating in order to reduce wear and damage due to sliding with the high friction layer 50.

The platen 33 is a portion that supports the recording paper P from below when printing on the recording paper P by the head unit 5, and has an upper surface substantially parallel to the horizontal plane.
The diamond ribs 34 are protrusions that protrude upward from the upper surface of the platen 33, and a plurality of diamond ribs 34 are arranged at intervals along the axial direction of the transport roller 31. The top surface of the diamond rib 34 is formed substantially parallel to the horizontal plane, and the recording paper P during printing is supported from below by this top surface.

  The paper discharge unit 4 discharges the printed recording paper P from the transport unit 3, and includes a paper discharge roller 41 and a paper discharge jagged roller 42. The paper discharge roller 41 and the paper discharge jagged roller 42 can rotate in directions opposite to each other, and the recording paper P is pulled out and discharged by this rotation.

The head unit 5 ejects ink onto the recording paper P placed on the transport unit 3 and includes an ejection head 51 and a carriage 52.
The ejection head 51 is a device that ejects ink in accordance with an instruction from the control unit CONT, and an ejection port (not shown) is provided to face the top surface of the diamond rib 34. The carriage 52 holds the ejection head 51 below, and is provided so as to be reciprocally movable in the axial direction of the transport roller 31. The carriage 52 is connected to a drive unit (not shown) that reciprocates the carriage 52 in accordance with the support of the control unit CONT.

Next, a configuration for rotationally driving the transport roller 31 will be described with reference to FIG.
2A and 2B are schematic views showing the configuration of the transport unit 3 and the paper discharge unit 4, where FIG. 2A is a plan view, and FIG. 2B is a view taken in the direction of arrow A in FIG.

As described above, the transport unit 3 has the drive unit 6. The driving unit 6 rotates the transport roller 31 and includes a motor 61 and a pinion gear 62.
The motor 61 is an electric motor that rotates the transport roller 31 in accordance with an instruction from the control unit CONT. That is, the control part CONT controls and drives the motor 61 to realize the rotation of the transport roller 31 and the accurate transport of the recording paper P. The pinion gear 62 is a gear that is integrally connected to the output shaft of the motor 61.

  The transport roller 31 has a first drive gear on one end side (left side in FIG. 2A) with respect to the transport area CA (see FIG. 3) in contact with the recording paper P in the length direction (axial direction). 35 and a second drive gear 36 are provided, and a third drive gear 37 is provided on the other end side (left side in FIG. 2A) from the conveyance area CA.

  The first drive gear 35 is a gear for rotating the transport roller 31, and is integrally connected to the end of the transport roller 31 on the drive unit 6 installation side by press-fitting. The first drive gear 35 meshes with the pinion gear 62, and the driving force of the motor 61 is transmitted to the transport roller 31 via the pinion gear 62 and the first drive gear 35, so that the transport roller 31 rotates. It has become.

The second drive gear 36 is a gear for transmitting the driving force of the motor 61 to a paper discharge roller 41 as a processing device, and has a smaller diameter than the first drive gear 35. Adjacent and coaxial.
The third driving gear 37 transmits the rotational driving force of the transport roller 31 to another device 38, for example, a pump for covering (capping) and sucking the nozzles of the ejection head 51. More specifically, as a device to which the rotational driving force is transmitted via the third drive gear 37, a device that is inactivated when the transport roller 31 transports the recording paper P is set.
A method of connecting the second drive gear 36 and the third drive gear 37 and the transport roller 31 will be described later.

  A discharge driving gear 43 is integrally provided at the end of the discharge roller 41 on the drive unit 6 side. An intermediate gear 44 is provided between the paper discharge drive gear 43 and the second drive gear 36, and the intermediate gear 44 meshes with each of the second drive gear 36 and the paper discharge drive gear 43. That is, the driving force of the motor 61 is transmitted to the paper discharge roller 41 via the second drive gear 36, the intermediate gear 44, and the paper discharge drive gear 43, and the paper discharge roller 41 rotates, so that it is discharged as processing related to printing. The paper processing is performed.

FIG. 3 is a diagram illustrating a schematic configuration of the transport roller mechanism 19 including the transport roller 31 and the driven roller 32.
The transport roller 31 includes a roller body 16 formed into a cylindrical shape by pressing a metal plate such as a galvanized steel plate or a stainless steel plate, and a high friction layer 50 provided on the surface of the roller body 16. Is. The high friction layer 50 is formed with a length equivalent to the conveyance area CA for the maximum width of the recording paper P that can be printed by the printer 1. For example, a resin layer made of an epoxy resin or a polyester resin, and the resin layer Ceramic particles dispersed on the surface. Aluminum oxide (alumina), silicon carbide, silicon dioxide or the like is used for the ceramic particles. The particle diameter of the ceramic particles is adjusted by a crushing process, and the ceramic particles have a shape having relatively sharp edges by using the crushing process.

  Further, both ends of the transport roller 31 are rotatably held by the bearing 70. Further, the roller body (cylindrical shaft) 16 is formed in a cylindrical shape by pressing a metal plate and bringing a pair of opposed end portions (end surfaces) close to each other or abutting each other. Accordingly, the roller main body 16 has a joint formed between the pair of end portions, but in the present embodiment, the joint has a different configuration in the vicinity of the conveyance area CA and at both end portions.

  Specifically, as shown in FIG. 4, the joint 80 in the present embodiment is formed at the central straight portion 86 formed in the central portion including the conveyance area CA in the roller body 16 and at both ends of the roller body 16. And a bent portion 85 to be formed. The high friction layer 50 described above is formed on the central straight portion 86. As shown in FIG. 5, a pair of end portions (end surfaces) 61a and 61b located at the center portion in the length direction of the metal plate 60 having a substantially rectangular shape in plan view are formed into a cylindrical shape by bending the center straight line portion 86. Sometimes formed by joining. Further, the bent portions 85 are located at both ends in the length direction of the metal plate 60, and are rectangular protrusions 61c protruding from the end surface 61a in the width direction (the circumferential direction around the central axis 16a when formed into a cylindrical shape). And a rectangular recess 61d in which the end face 61b is missing in the width direction (a circumferential direction around the central axis 16a when formed into a cylindrical shape) is formed at the same width and the same pitch along the central axis 16a direction, As shown in FIG. 4, it is formed in a ninety-nine fold shape including the intersecting portion 85a and the intersecting portion 85b extending in the direction intersecting the central axis 16a by the concavo-convex portion 110 that fits when molded into a cylindrical shape. The

Further, as shown in FIG. 6A, one end of the roller body 16 (conveying roller 31) has a D-cut shape for connection with the second drive gear 36 shown in FIG. An engaging portion (positioning portion) 73 having a notch shape is formed. The engaging portion 73 is formed at the end of the cylindrical roller body 16 (conveying roller 31). As shown in FIG. 6B, a part of the engaging portion 73 is cut out in a rectangular shape in plan view. An opening 73a is formed, whereby the outer shape of the side surface of the end is formed in an apparent D shape as shown in FIG. 6 (c).
Therefore, a connecting part (not shown) such as a gear is engaged with the engaging portion 73 formed in an apparent D-shape so that the connecting part is attached to the roller body 16 without being idle. be able to. Further, since the engaging portion 73 is formed with a groove-like opening 73a that communicates with the internal hole of the hollow pipe (roller body 16), the connecting component can also be connected to the developing roller by using the opening 73a. It can be attached to 510 without making it idle. Specifically, a convex portion may be formed on the connecting component, and the convex portion may be fitted into the opening 73a to prevent idle rotation.

Although not shown in FIG. 6A, an engaging portion 73 is similarly formed on the other end side of the roller body 16 (conveying roller 31), as shown in FIG. 6B. The third driving gear 37 can be positioned and fixed by engaging the engaging portion 73 with the third driving gear 37.
In addition, illustration of the joint 80 is abbreviate | omitted in FIG. 6 (a), (b).

Here, as a detailed description of the transport roller 31, a manufacturing method thereof will be described with reference to FIGS. 5 and 7 to 11.
The process of manufacturing the transport roller 31 includes a pressing process (first process) in which the base material of the roller body 16 is bent to form a cylindrical shape, and the engaging portions 73 are formed at both ends of the roller body 16 formed in the pressing process. It includes a step (first step) and a correction step (second step) for correcting the axial bending generated in the roller body 16 formed in the pressing step (and the step of forming the engagement hole 73).

In the present embodiment, in addition to the above steps, a centerless processing step (third step) for polishing the surface of the roller body 16 whose axis has been corrected is also added.
Hereinafter, each step will be described.

(Pressing process)
In order to manufacture the conveyance roller 31, first, a large rectangular metal plate or strip is prepared. As the large metal plate, for example, a galvanized steel plate having a thickness of about 1 mm is used. Subsequently, the large metal plate is cut by pressing, and as shown in FIG. 5, a long and substantially rectangular metal plate 60 having a size corresponding to the roller body 16, that is, the base material of the roller body 16. A metal plate 60 is formed.

  However, when this large metal plate is pressed, at the same time as the above-described cutting process, a pair of opposing long sides are formed to form a bent portion at the joint formed between the pair of end portions described above. A rectangular wave-shaped concavo-convex portion 110 is formed at both ends of the portions 61a and 61b in the length direction. Moreover, in each long side (end part), the linear part 111 is formed between the uneven | corrugated | grooved part 110 formed in the both ends.

  Since the pair of long sides (end portions 61a and 61b) are brought close to each other or brought into contact with each other by pressing, of course, between the portions corresponding to (opposing) each other, the concave and convex portions on one long side. When 110 becomes a convex part, it forms so that it may become a recessed part in the uneven part 110 of the other long side. Conversely, when the concave / convex portion 110 on one long side becomes a concave portion, the concave / convex portion 110 on the other long side becomes a convex portion.

Next, the metal plate 60 is pressed into a cylindrical shape (pipe shape) as shown in the press working steps of FIGS. 7 (a) to 7 (c) and FIGS. 8 (a) to 8 (c). Side) end portions 61a and 61b are brought close to or in contact with each other.
That is, first, the metal plate 60 is pressed by the male mold 101 and the female mold 102 shown in FIG. 7A, and both side portions 62a and 62b of the metal plate 60 are formed in an arc shape (preferably approximately 1/4 arc). Bend. In FIG. 7 (a), these members are shown with a space between the metal plate 60, the male mold 101, and the female mold 102 in order to make each member easy to understand. In reality, it does not exist, and the metal plate 60 and the male mold 101 and the female mold 102 are in close contact with each other at their contact portions. The same applies to FIGS. 7B and 7C and FIGS. 8A to 8C described later.

Subsequently, the central portion in the width direction (bending direction) of the metal plate 60 obtained in FIG. 7A is pressed with the male mold 103 and the female mold 104 shown in FIG. It is preferably bent to approximately 1/4 arc).
Next, as shown in FIG. 7C, a core die 105 is arranged inside the metal plate 60 obtained in FIG. 7B, and an upper die (press die) 106 shown in FIG. Using the lower mold (press mold) 107, as shown in FIGS. 8A to 8C, the end surfaces (end portions) 61a and 61b of the both side portions 62a and 62b of the metal plate 60 are brought close to each other.

  Here, the outer diameter of the core mold 105 shown in FIGS. 7C and 8A to 8C is equal to the inner diameter of the cylindrical hollow pipe to be formed. The radius of the press surface 106c of the upper die 106 and the radius of the press surface 107a of the lower die 107 are equal to the radius of the outer diameter of the hollow pipe to be formed. Further, as shown in FIGS. 8A to 8C, the upper mold 106 is a pair of left and right split molds, and the split molds 106a and 106b are configured to be able to move up and down independently.

Then, from the state shown in FIG. 7 (c), the upper die 106a on the right side is lowered relative to the lower die 107 as shown in FIG. 8 (a). ), One side of the metal plate 60 is pressed and bent into a substantially semicircular shape. The lower mold 107 may also be a pair of left and right split molds (see the split surface 107b) like the upper mold 106, and the lower mold on the same side may be raised during the process shown in FIG.
Next, as shown in FIG. 8B, the core mold 106 is slightly lowered (to the extent that the end 61a on one side and the end 61b on the other side can be brought close to each other) and the other side. The upper die 106b is lowered and the other side of the metal plate 60 is pressed and bent into a substantially semicircular shape.

  Thereafter, as shown in FIG. 8C, the core mold 105 and the pair of upper molds 106a and 106b are lowered to form a cylindrical hollow pipe (roller body 16). In this state, the left and right end portions 61a and 61b are in contact with each other. That is, in this cylindrical hollow pipe, both ends 61a and 61b of the metal plate 60 as a base material are brought into close contact with each other, so that a joint is formed between these both ends 61a and 61b. The

  Subsequently, engaging portions 73 are formed at both ends of the cylindrical hollow pipe (roller body 16) formed as described above. As a method for forming the engaging portion 73, polishing processing, cutting processing, or the above-described press processing or the like can be employed (the press processing will be described later).

  As described above, the roller body 16 formed in the above pressing step is subjected to a tensile force on the outer peripheral surface side than the neutral surface, and the presence of the joint 80 causes the circumferential direction to be opposite to the joint. A force in the direction of contraction around the position (position facing the center of the axis) acts, and a force in the direction of contraction around the center also acts in the length direction. As a result, as shown in FIG. 9A, the roller main body 16 is warped (axially bent) so that the joint 80 bulges toward the outside in the central portion in the length direction (hereinafter, referred to as “below”). The axial bend in this direction is bent upward, and the axial bend in the opposite direction is referred to as downward bend). Therefore, this axial bending is corrected in a subsequent correction process.

(Correction process)
The correction process in the present embodiment includes a bending process that temporarily forms a bending in a direction opposite to the direction of the axial bending that has occurred in the pressing process, and a direction that is opposite to the direction in which the bending load is applied in the bending process. A reverse load applying step for applying a load.
Hereafter, each process is demonstrated with reference to Fig.9 (a)-(c).

  As shown in FIG. 9A, for the roller body 16 in which the upper bend occurs, the pressing pins 106m and 106n as shaft-like members provided in the upper mold 106 so as to be able to advance and retreat, and the lower mold 107 can be advanced and retracted. A bending load is applied by pressing pins 107m and 107n serving as shaft-like members provided on. The pressing pin 106m is provided at a position where the upper mold 106 is pressed substantially at the center in the length direction of the roller body 16. The pressing pins 106n are provided on the upper die 106 in positions near the both ends in the length direction of the roller body 16 so as to support and press the center side of the engaging portion 73. The pressing pin 107m is provided at a position where the lower mold 107 is pressed substantially at the center in the length direction of the roller body 16. The pressing pins 107n are provided on the lower mold 107 in positions near the both ends in the length direction of the roller body 16 so as to support and press the center side of the engaging portion 73.

  For the roller body 16 that has been bent upward in the pressing process, in the bending process, the pressing pins 107n provided on the lower mold 107 are protruded to support the vicinity of both ends of the roller body 16 from below. The pressing pin 106m provided on the upper die 106 is projected to support the joint 80 at the center of the roller body 16 from above, and the pressing pins 107n and 106m are further projected to press the roller body 16. Apply bending load. At this time, as shown in FIG. 9B, the roller body 16 is pressed by the pressing pin 106m so that the roller body 16 is bent downward, and a bending load is applied.

Subsequently, in the reverse load applying step, as shown in FIG. 9B, the pressing pin 107 m provided on the lower die 107 is protruded to support the central portion of the roller body 16 from below, and the upper die 106 is The provided pressing pin 106n is protruded to support the vicinity of both end portions of the roller body 16 from above, and the pressing pins 107m and 106n are protruded to press the roller body 16 and apply a bending load.
Thereby, as shown in FIG.9 (c), the axial bending of the roller main body 16 is corrected.

(Centerless machining process)
Next, in this embodiment, a centerless processing step (third step) for polishing the outer peripheral surface of the hollow pipe (roller body 16) in order to increase the roundness of the formed hollow pipe (roller body 16) and reduce the runout. ) Is added.
This centerless polishing is performed over the entire surface. For example, the ten-point average roughness Rz of the surface after the centerless polishing is set to 1.0 μm or less.
Thereby, the roundness of the hollow pipe becomes better than that before the centerless polishing process, and the roller body 16 has a small deflection amount.

(Example)
The axial bending amount (warping amount) of the plurality of roller bodies 16 formed into a cylindrical shape in the pressing process described above was 100 to 150 μm, but the axial bending amount of the roller body 16 that was bent downward in the bending formation process. The (warpage amount) was around 250 μm. Furthermore, by applying a reverse load in the reverse load applying step, the amount of axial bending of the roller body 16 was 20 to 50 μm. Then, by performing centerless polishing on the roller body 16 with the shaft bending corrected in this way, the amount of deflection could be suppressed to 50 to 100 μm.

  As shown in FIG. 4, the joint 80 formed in this way is fitted with the uneven portion 110 shown in FIG. 5, so that the bent portions having the intersecting portions 85 a and 85 b are formed at both ends of the roller body 16. A portion 85 is formed.

When the roller body 16 is formed in this manner, the high friction layer 50 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 these methods in combination) can be employed, but a dry method is preferably employed.

Next, the operation of the printer (printing apparatus) 1 including the transport roller mechanism 19 will be described with reference to FIGS.
When the recording paper P fed by the paper feed roller 22 reaches the vicinity of the upstream side of the transport roller mechanism 19, it is drawn between the transport roller 31 and the driven roller 32 by the drive of the motor 61, thereby driving both rollers. Is conveyed at a constant speed toward the lower side of the ejection head 51 located on the downstream side.

  At this time, since the high friction layer 50 is formed on the transport roller 31 and the driven roller 32 is disposed at a position where the high friction layer 50 is in contact with the transport roller 31, between the transport roller 31 and the driven roller 32. The force for pinching the recording paper P is increased, and the transportability of the recording paper P is improved.

Then, when the printing start end of the recording paper P reaches a predetermined printing position directly below the ejection head 51, printing is started.
Thereafter, when the starting edge of the recording paper P reaches the paper discharge unit 4, that is, the paper discharge roller 41 and the paper discharge roller 42, the paper discharge operation of the recording paper P sandwiched between them is started.

  Here, the rotational driving of the paper discharge roller 41 is caused by the driving force of the motor 61 transmitted to the transport roller 31 via the first drive gear 35 being transmitted via the second drive gear 36, and driving the transport roller 31. Although it is also performed during the conveyance process of the recording paper P, since both the first drive gear 35 and the second drive gear 36 are arranged on one end side with respect to the conveyance area CA of the conveyance roller 31, the conveyance roller 31. Torque applied to the (roller body 16) does not act on the conveyance area CA. For this reason, the seam 80 (the central straight line portion 86) in the transport area CA is not displaced, and hence the recording paper P is transported obliquely, and the transport accuracy and thus the print accuracy are reduced. This can be suppressed.

  On the other hand, the driving force of the motor 61 transmitted to the transport roller 31 via the first drive gear 35 is transmitted to another device 38 via the third drive gear 37. In this case, since the third drive gear 37 is disposed on the other end side of the transport roller 31 on the opposite side to the first drive gear 35 across the transport area CA, the transport area CA includes other devices 38. Although the torque according to the operation is applied, the third drive gear 37 is connected to the device 38 which is inactivated when the transport roller 31 transports the recording paper P, so that recording is performed when the device 38 is operated. The paper P is not transported, and therefore the transport accuracy, and hence the printing accuracy, is not reduced. Furthermore, in this embodiment, since the joint 80 of the transport roller 31 in the feeding area CA is the central straight portion 86, and the length of the joint 80 is minimized, the transport due to the joint 80 is performed. A decrease in accuracy and printing accuracy can be further suppressed.

  As described above, in the present embodiment, since the warpage generated in the pressing process is corrected in the correction process, it is possible to reduce the shake when the transport roller 31 is rotated, thereby reducing the transport characteristics. Can be suppressed. In particular, in this embodiment, a bending load is applied to the joint at the center in the length direction with respect to the warped so that the joint of the roller body 16 bulges outward, which is effective. The shaft bending can be corrected. Furthermore, in this embodiment, since the roller main body 16 is supported on the center side from the end engaging portion 73 where large stress tends to remain at the time of formation, it is possible to apply a bending load to the roller main body 16 with high accuracy and effectively. It is possible to correct the axial bending of the roller body 16.

Further, in the present embodiment, after forming the bending in the reverse direction in the bending formation process to the axial bending generated in the pressing process, the reverse load is applied in the reverse load applying process, and thus the roller body 16 is generated in the pressing process. Since the residual stress can be relaxed once, it becomes possible to reduce the bending after correction as compared with the case where the bending load is applied only in one direction.
In addition, in this embodiment, since the axial bending of the roller body 16 is corrected using the pressing pins 106m, 106n, 107m, and 107n provided on the upper mold 106 and the lower mold 107, a bending load is applied to the roller body 16. There is no need to separately provide a device for applying, or transfer to a device for applying a load to the roller body 16, which can contribute to an improvement in productivity and a reduction in size and cost of the device.

  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. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above-described embodiment, the configuration in which the straightening process includes the bending forming process and the reverse load applying process is illustrated, but the present invention is not limited to this, and the pressing pins 106m and 107n from the state illustrated in FIG. Thus, the bending load may be applied in such an amount that the axial bending of the roller body 16 is zero, and the state shown in FIG.
Even in this case, by supporting the roller body 16 at the center side from the engaging portion 73, the axial bending amount (warping amount) of the plurality of roller bodies 16 formed into a cylindrical shape in the pressing process is from 100 to 150 μm. The amount of runout can be suppressed to 20 to 80 μm by performing centerless polishing on the roller main body 16 whose shaft bending is corrected in this way.

In the above-described embodiment, the pressing pins 106m and 106n and the pressing pins 107m and 107n are arranged to face each other, both ends of the roller body 16 are pressed on one side, and the center of the roller body 16 is pressed on the other side. However, the present invention is not limited to this. For example, as shown in FIG. 10, the lower mold 107 is located at a position spaced apart from the engaging portion 73 by a predetermined distance in the length direction of the roller body 16 (first pressing position). A plurality of pressing pins 107p are provided on the side, positioned between the pressing pins 107p on the upper mold 106, and from the engaging portion 73 at a position (second pressing position) facing the pressing pins 107p in the radial direction of the roller body 16. Alternatively, a plurality of pressing pins 106p may be provided on the center side.
Thereby, in this embodiment, since the press position with respect to the roller main body 16 increases, a finer correction | amendment is attained and the shake amount of the roller main body 16 can be made still smaller.

Moreover, in the said embodiment, although it was set as the structure which presses also the center part containing the conveyance area | region CA in the roller main body 16, for example, as shown in FIG. 11, it is separated from the conveyance area | region CA containing the high friction layer 50 in the roller main body 16. As shown in FIG. It is good also as a structure which arrange | positions the pressing pins 106p and 107p in the position which carried out.
In this configuration, it is possible to prevent the conveyance characteristics with respect to the recording medium from being deteriorated due to a press mark or the like generated when a bending load is applied to the conveyance area CA of the roller body 16.
In addition, both the pressing pins 106p and 107p do not apply a bending load to the roller body 16, but one of the pressing pins 106p and 107p only supports the center side of the engaging portion 73, and only the other is engaged. It is good also as a structure which gives a bending load to the center side rather than the part 73. FIG.

Moreover, in the said embodiment, although the bending part 85 in the joint 80 of the roller main body 16 was set as the structure formed of the rectangular-shaped protrusion 61c and the rectangular recessed part 61d, in addition to this shape, for example, FIG. 12 (a), the intersecting portion 85a of the bent portion 85 is inclined with respect to the circumferential direction (vertical direction in FIG. 12 (a)) and intersects with an axis parallel to the central axis 16a at an angle α. It is good also as a structure. In this way, when the pair of end surfaces are brought close to each other in the press working of the metal plate, the tip of the protrusion 61c can be easily fitted into the corresponding recess 61d, and thus the roller body 16 is distorted or twisted. Can be suppressed.
Further, as shown in FIG. 12 (b), a configuration in which the bent portion 85 is formed by a repetitive arc-shaped joint (sin wave shape), or a triangular projection as shown in FIG. 12 (c). A configuration in which the joint is formed in a zigzag shape by the 61c and the recess 61d may be employed.

  Moreover, in the said embodiment, although the engaging part 73 which has the D cut notch shape provided in the edge part of the roller main body 16 was shown, as shown to Fig.13 (a), (b), a roller main body An engaging portion (positioning portion) 74 having a groove 74a and a D-cut portion 74b can also be formed at the end portion of 16. In this engagement portion 74, the D cut portion 74b is formed at the outer end of the roller body 16, and the groove 74a is formed inside the D cut portion 74b. As shown in FIG. 13A, the groove 74a is formed by cutting the roller body 16 approximately half in the circumferential direction. The D-cut portion 74b has an opening 74c extending in a direction orthogonal to the groove 74a outside the groove 74a, and has a pair of bent pieces 74d and 74d on both sides of the opening 74c. That is, as shown in FIG. 13 (b), when the pair of bent pieces 74d and 74d are bent toward the central axis side of the roller body 16, the portions corresponding to the bent pieces 74d and 74d are The roller body 16 is recessed from the circular outer peripheral surface.

  Accordingly, by engaging a connecting part (not shown) such as a gear with the groove 74a or with the D-cut portion 74b, the connecting part is idled with respect to the roller body 16 (conveying roller 31). Can be installed. In addition, the engaging portion 74 can be attached to the roller body 16 without making it idle by using the opening 74c formed between the bent pieces 74d. Specifically, by forming a convex portion on the connecting component and fitting the convex portion into the opening 74c, it is possible to prevent idling.

  Further, as shown in FIGS. 14A and 14B, an engaging portion (positioning portion) 75 having a groove 75 a and an opening 75 b can be formed at the end of the roller body 16. In the engaging portion 75, the opening 75b is formed at the outer end of the roller body 16, and the groove 75a is formed inside the opening 75b. As shown in FIG. 14A, the groove 75 a is formed by cutting the roller body 16 approximately half in the circumferential direction. In the opening 75b, a part of the roller main body 16 is cut out in a rectangular shape in plan view outside the groove 75a, and as a result, the outer shape of the end side surface is formed in an apparent D shape as shown in FIG. It is a thing.

  Accordingly, a connecting part (not shown) such as a gear is engaged with the groove 75a or an apparently D-shaped part formed by the opening 75b, thereby making the connecting part a roller. The main body 16 can be attached without being idle. Moreover, also in this engaging part 75, similarly to the engaging part 73 shown to Fig.6 (a)-(c), by using the opening 75b, it attaches without making a connection component idle with respect to the roller main body 16. FIG. be able to.

In order to form such engagement holes 71 and engagement portions 73, 74, and 75, as described above, further cutting and polishing are performed on the roller body 16 obtained by pressing the metal plate 60. This can be done by processing.
However, when the roller body 16 is further processed in this way, the cost and time efficiency are reduced by adding a separate processing step only for the formation of the engaging portion. Therefore, before the roller body 16 is subjected to press processing, a deployment engagement portion that becomes an engagement portion is formed on the metal plate by press processing, and when the metal plate is pressed to form the roller body 16, It is preferable to form the joint at the same time.

  Specifically, when a large metal plate is pressed into the elongated rectangular plate-shaped metal plate 60 shown in FIG. A deployment engagement portion such as a shape, a hole shape, or a groove shape is formed. For example, as shown in FIG. 15 (a), the end of the metal plate 60 is cut out into a predetermined shape to form a deployment engagement portion 76b, and the metal plate 60 is pressed to form FIG. 13 (a). , (B) can be formed. That is, the engaging portion 74 can be formed by forming a pair of notches (recessed portions) 74e and 74e and a pair of projecting pieces 74f and 74f as the deployment engaging portion 76b. However, in this example, after the metal plate 60 is pressed, the pair of projecting pieces 74f and 74f must be folded and pressed inward to form the bent piece 74d. It is somewhat insufficient to increase the conversion.

  Therefore, as shown in FIG. 15 (c), the end of the metal plate 60 is cut out into a predetermined shape to form a deployment engagement portion 76c, whereby the metal plate 60 is pressed to form FIG. 14 (a). , (B) can be formed. That is, the engaging portion 75 can be formed by forming a pair of notches (recessed portions) 75c and 75c and a pair of projecting pieces 75d and 75d as the deployment engaging portion 76c. In this example, when the metal plate 60 is pressed, the pair of projecting pieces 75d and 75d are also bent in an arc shape, thereby forming an opening 75b shown in FIG. 14B between the projecting pieces 75d and 75d. be able to. Therefore, it is not necessary to add further processing to the roller main body 16 formed by press processing, and thereby the cost and time efficiency of the processing steps can be sufficiently increased.

Further, as the ceramic particles (for example, alumina particles) forming the high friction layer 50 shown in the above embodiment, the particle diameter is in the range of 15 μm or more and 90 μm or less, and the weighted average particle diameter (average) is the center diameter. It is preferable to use one having a particle diameter adjusted so as to be 45 μm.
That is, as the alumina particles (inorganic particles), those having an average particle diameter (center diameter) larger than the distance d1 (30 μm) on the outer peripheral surface side of the joint 80 are used as shown in FIG. 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. 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, that is, the distance d2 on the inner peripheral surface side.

When the high friction layer 50 is formed in this way, the gap between the end surfaces 61a and 61b is mainly formed in the joint 80, without forming a groove due to the gap between the end surfaces 61a and 61b of the metal plate 60. Embedded with alumina particles 95.
That is, since the alumina particles 95 having an average particle diameter larger than the distance d1 on the outer peripheral surface side of the joint 80 are used, most of the alumina particles 95 do not enter the joint 80. As shown in FIG. 16, it adheres to the outer peripheral surface of the roller body 16 through a resin film 151. Therefore, although the gap 80 is formed between the end faces 61a and 61b of the metal plate 60 in the joint 80, the alumina particles 95 cover the gap, so that the groove due to the gap is substantially free. No longer formed.

Further, as the alumina particles 95, a particle size distribution (particle size range) including particles 95a which is 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. 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 main body 16 (conveying roller 31) in the direction of narrowing the gap during use, the alumina particles 95a that enter here resists this force, so the roller main body 16 (conveying roller 31). 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.

  Further, the alumina particles 95 having a minimum particle size in the particle size distribution that 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, are used. Therefore, when the alumina particles 95 are arranged on the surface of the roller body 16 to form the high friction layer 50, the alumina particles 95 do not enter the roller body 16 through the gap formed in the joint 80. Therefore, processing such as cleaning the inside of the roller body 16 is reduced thereafter, and productivity can be improved correspondingly.

Moreover, as shown to Fig.17 (a), the opening 70 may be provided in a part of joint 80 formed in the roller main body 16 shown in the said embodiment.
As shown in FIG. 17B, the joint 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 joint 80 may be formed as a gap with the end surfaces 61a and 61b slightly spaced apart without the pair of end surfaces 61a and 61b coming into contact with each other. And since this joint 80 is formed over the full length of the conveyance roller 31, when the grease supplied to the bearing adheres to the surface of the conveyance roller 31, the grease will be transmitted through the joint 80 by capillary action. In particular, as the joint 80 (maximum distance d1 between the end surfaces 61a and 61b) is reduced in order to improve the strength of the transport roller 31, the capillary phenomenon of the grease becomes stronger and the grease tends to flow along the joint 80. .

Therefore, as shown in FIG. 17C, an opening 170 is provided in a part of the joint 80 formed in the roller body 16. As shown in FIG. 17C, the opening 170 is formed by notches 76 and 77 provided in a pair of end surfaces 61a and 61b forming the joint 80, respectively. When the end surfaces 61a and 61b are brought into contact with each other, the maximum distance d2 between the notches 76 and 77 is set to be, for example, about 1 mm or more, and functions as the opening 170.
The opening 170 is provided in a region excluding a region where the high friction layer 50 is formed and a region supported by the bearing 26 in the joint 80 formed over the entire length of the transport roller 31 (roller body 16). That is, the high friction layer 50 is formed in the substantially center part of the conveyance roller 31, and since the both ends of the conveyance roller 31 are supported by the bearing, the conveyance roller 31 is provided with at least two openings 170.

  The opening 170 is provided for the purpose of preventing the grease (lubricant) supplied (applied) to the bearing 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 action of grease is stopped. Specifically, by providing an opening 170 between the region supported by the bearing 26 and the region where the high friction layer 50 is formed in the joint 80, the grease is prevented from reaching the high friction layer 50. ing. Then, by adjusting the size of the opening 170 (maximum distance d2 between the pair of cutout portions 76 and 77), the capillary action of grease can be reliably stopped.

  Note that the present invention is not limited to the case where the notches 76 and 77 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. 17D, a notch 78 is formed only on one of the pair of end surfaces 61a and 61b (for example, the end surface 61a) forming the joint 80, and the notch 78 and the end surface 61b It may be a case where the opening 170 is formed. The shape of the opening 170 is not limited to a rectangle, and may be a circle or the like.

Moreover, you may make the shape of the joint 80 formed in the roller main body 16 into a shape as shown in FIG. That is, in the joint 80, the first end surface 174 and the second end surface 175 are in contact with each other on the outer peripheral surface 16 a side of the roller body 16. The gap between the first end surface 174 and the second end surface 175 gradually becomes wider from the radially outer side toward the inner side. Moreover, the shape of the 1st end surface 174 and the 2nd end surface 175 becomes the same shape over the full length of the roller main body 16 except a bending part.
Further, the first angle α formed by the first end surface 174 and the outer peripheral surface 16a and the second angle β formed by the second end surface 175 and the outer peripheral surface 16a are both smaller than 90 °. .

  The first end surface 174 and the second end surface 175 of the joint 80 are in contact with each other on the outer peripheral surface 16a side, and the smoothness on the outer peripheral surface 16a side of the joint 80 is improved. Therefore, even if the transport roller 31 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. 19, the shape of the joint 80 is such that the first angle α formed by the first end surface 174 and the outer peripheral surface 16a of the joint 80 is smaller than 90 °, and the second end surface 175 and the outer periphery are formed. The second angle β formed with the surface 16a may be formed with a size of 90 ° or more. In other words, the first end surface 174 and the second end surface 175 in the connection portion 80 may have a shape inclined in a predetermined direction with respect to the circumferential direction.

The shape of the joint 80 is formed through the following steps. That is, after the metal plate 60 is formed by punching in progressive press processing, end surface adjustment processing is performed on the first end surface 174 and the second end surface 175 of the metal plate 60, and the first end surface 174 and the second end surface are processed. The inclination of 175 with respect to the outer peripheral surface 16a is adjusted.
As shown in FIG. 20, the inclination with respect to the outer peripheral surface 16a of the 1st end surface 174 and the 2nd end surface 175 is adjusted by press work. By this adjustment, the first angle α formed by the first end surface 174 and the outer peripheral surface 16a and the second angle β formed by the second end surface 175 and the outer peripheral surface 16a are both smaller than 90 °.
Accordingly, when the cylindrical roller body 16 is formed by bending the metal plate 60, the first end surface 174 and the second end surface 175 are in contact with each other at least on the outer peripheral surface 16a side.

Since the roller main body 16 (conveyance roller 31) is formed using the metal plate 60 in which the winding by the steel plate coil remains, the surface that was on the inner peripheral side of the coil becomes the inner peripheral surface of the roller main body 16. It is preferable to form.
That is, the winding of the metal plate 60 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. That is, the metal plate 60 that forms the roller body 16 has a wrapping that warps toward the inner peripheral surface of the roller body 16.

  Therefore, winding does not act at least in the direction in which the joint 80 of the roller body 16 is opened. Therefore, it is possible to make it difficult to open the joint 80 of the roller main body 16 as compared with the case where the winding that warps to the outer peripheral surface side of the roller main body 16 remains. Thereby, even if it is a case where stress acts in the direction which opens the joint 80 of the roller main body 16, the joint 80 can be prevented from opening, and the transport roller 31 with high transport accuracy can be obtained.

  Moreover, the circumferential direction (bending direction) of the roller main body 16 and the winding direction of the steel plate coil (the rolling direction of the metal plate 60) are the same. Therefore, the bending direction of the metal plate 60 forming the roller body 16 can be matched with the direction of warping due to winding. Thereby, the winding of the metal plate 60 that forms the roller body 16 acts in a direction to close the joint 80 of the roller body 16. Accordingly, the opening of the joint 80 of the roller body 16 can be more effectively prevented.

Further, it is preferable that sagging, burrs and the like formed on the cut surface of the metal plate 60 in the step of removing the roller main body 16 are arranged on the inner peripheral side of the roller main body 16.
That is, the roller body 16 (conveyance roller 31) is formed using, as a base material, a metal plate 60 that has been die-cut by a punching process as shown in FIGS. That is, the metal plate 60 that is the base material of the roller body 16 is bent into a cylindrical shape with the upper surface C2 facing the male mold 131 shown in FIG. Then, a seam 80 is formed in which the pair of end faces 61a and 61b face each other.
For this reason, even when a sagging sd, a shear surface sp, a fractured surface bs, and a burr (not shown) are formed on the metal plate 60 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 C1 of the metal plate 60 continuing to the burr and the fracture surface bs is on the inner peripheral side of the roller body 16.

Thereby, when the roller main body 16 having the seam 80 is formed by abutting the pair of end surfaces 61 a and 61 b of the metal plate 60, it is possible to prevent the seam 80 from opening due to the burrs and the unevenness of the fracture surface bs.
Therefore, the accuracy of the seam 80 of the roller body 16 can be improved, and the conveyance roller 15 that can obtain high conveyance accuracy can be provided. Moreover, the burr | flash becomes the inner peripheral surface side of the roller main body 16, it can prevent protruding from the outer peripheral surface of the roller main body 16, and a burr removal process can be skipped and productivity can be improved.

Further, in addition to the configuration of the deployment engagement portion shown in FIG. 15, as shown in FIGS. 22 (a) to 22 (c), the deployment engagement portion is not formed at both ends of the metal plate 60, and its width It can also be formed near the center line in the direction (bending direction). That is, as shown in FIG. 22 (a), the engaging portion 73 shown in FIG. 6 can be formed by forming a deployment engaging portion 76d composed of an elongated rectangular cutout at the end. Further, by forming a deployment engagement portion 76e formed of a T-shaped notch as shown in FIG. 22B, the engagement portion 74 shown in FIG. 13 can be formed, and further, FIG. The engaging portion 75 shown in FIG. 14 can be formed by forming the development engaging portion 76f formed of a substantially T-shaped notch as shown in c).
Thus, if the expansion | deployment formation parts 76d-76f are formed in the vicinity of the centerline in a bending direction, the engagement parts 73-75 obtained from these expansion | deployment formation parts 76d-76f can be formed more accurately.

  Moreover, in the conveyance roller 31 (roller main body 16) which concerns on this embodiment, although the joint 80 was formed so that it might become in parallel with the central axis of the roller main body 16 which consists of a cylindrical hollow pipe, this invention is this. For example, a joint formed between a pair of end portions of the metal plate 60 serving as a base is formed on the central axis of the cylindrical pipe on the outer peripheral surface of the cylindrical pipe (roller body). On a parallel straight line, it may be formed so as to overlap only at one or a plurality of points without overlapping with the line segment.

  Specifically, as shown in FIG. 23 (a), the outer peripheral surface of the roller body 16 is arranged in the circumferential direction so as to intersect with the joint 81 without being parallel to the central axis 16a of the roller body 16. While extending, the roller body 16 may be formed so as to extend from one end to the other end. In order to form the joint 81 in this way, the metal plate serving as the base material is not the elongated rectangular metal plate 60 as shown above, but an elongated parallelogram as shown in FIG. Using a metal plate 60a, press working is performed so that the straight line indicated by reference numeral 16b is the central axis. Thereby, the roller main body 16 shown in FIG. 23A is obtained, and the joint 81 is not parallel to the central axis 16a.

  In addition, in the roller main body 16 shown to Fig.23 (a), the joint 81 is formed from the one end of the roller main body 16 to the other end so that the surrounding surface may rotate only less than one round. This is to facilitate the press working of the metal plate 60a. However, as shown in FIG. 23 (c), the joint 82 may be formed so as to turn one or more times around the peripheral surface from one end to the other end of the roller body 16, that is, spirally. In that case, the angle θ in the elongated parallelogram-shaped metal plate 60a shown in FIG. 23B may be set to a more acute angle as the metal plate serving as the base material.

  If the joint is formed so as to overlap only at one or a plurality of points without overlapping the straight line parallel to the central axis of the cylindrical pipe (roller body 16), this roller body When the transport roller 31 having 16 transports the paper P in cooperation with the driven roller, that is, when transporting the paper, the transport speed of the paper P becomes constant, and uneven transport is more reliably prevented. It will be.

  That is, as shown in FIG. 24, the portion where the transport roller 31 contacts the paper P when the paper is fed is basically a straight line L on the outer peripheral surface, that is, a straight line parallel to the central axis 16a. Therefore, when the joint 80 of the transport roller 31 (roller body 16) is parallel to the central axis 16a of the roller body 16 as described above, the transport roller 31 is temporarily (instantaneously) the entire joint 80. ) In contact with the paper P. Then, since the groove is not formed due to the joint 80 as described above in the transport roller 31 of the present embodiment, there is no problem, but the groove is temporarily formed due to the joint 80. Then, this groove is temporarily and simultaneously in contact with the paper P, so that the entire width of the paper P is temporarily in contact with the groove due to the joint 80. As a result, the groove has a dent compared to the other outer peripheral surface of the transport roller 31 and the contact resistance with respect to the paper P is small, so the transport speed of the paper P is temporarily reduced, resulting in transport unevenness. End up.

  Thus, if the joints are formed as shown in FIGS. 23A and 23C, even if grooves are formed due to these joints, the grooves are simultaneously formed during paper feeding. Only one or a plurality of points are in contact with the paper P. Accordingly, there is almost no change in the contact resistance as compared with the case where the other surface (line) of the transport roller 31 hits, whereby the transport speed of the paper P becomes constant and transport unevenness is prevented.

  Moreover, about the joint of the conveyance roller 31 (roller main body 16) which consists of a cylindrical hollow pipe other than the example mentioned above, for example, as shown to Fig.25 (a), it is parallel to the central axis of the roller main body 16. It may be formed having a rectangular wave-like bent portion 85 composed of a straight portion 85a and a straight portion 85b orthogonal thereto. Even in the joint having such a bent portion 85, if a groove is temporarily formed due to the joint, the groove is simultaneously formed over the entire width of the sheet P during paper feeding. Since there is no contact, the conveyance speed of the paper P becomes substantially constant, and uneven conveyance is prevented.

Further, the bent portion 85 may be formed over the entire length of the roller body 16 as shown in FIG. 25 (b), and the central portion thereof as shown in FIG. 25 (c). You may selectively form in the both ends except. When the bent portions 85 are formed only at both ends as shown in FIG. 25C, a central straight portion 86 parallel to the central axis of the roller body 16 is formed between the bent portions 85. However, although not shown, the central straight portion between the bent portions 85 may be formed in an oblique line that is not parallel to the central axis 16a as shown in FIG.
Further, when the bent portion 85 is formed only at both end portions and the central portion between them is the central straight portion 86, the formation region of the high friction layer 50 described above corresponds to the central straight portion 86. It is preferable to do so.

  When the bent portion 85 is formed at the joint, and thus the bent portion 85 is made to be a fitting portion with unevenness, the bent portion 85 (fitting portion) is fitted as designed, and the tip of the convex portion and the tip It becomes difficult to make it approach (match) without a gap between the recesses corresponding to. Therefore, when the bent portion 85 is formed over the entire length of the roller body 16, the roller body 16 is likely to be distorted or twisted. Therefore, if the bent portions 85 are formed only at both ends as shown in FIG. 25C, it is possible to suppress the occurrence of such distortion and twist. In particular, by setting the central portion corresponding to the high friction layer 50, which is an area in direct contact with the paper P, to the central straight portion 86 instead of the bent portion 85, the area in direct contact with the paper P is distorted or twisted. Can be reliably prevented.

  In addition, as shown in FIG. 25 (b), when the bent portion 85 is formed over the entire length of the roller body 16, a joint formed by the bent portion 85 as shown in FIG. 26 (a). 87, a plurality of intersecting portions 87a composed of straight portions 85b, a first straight portion 87b connecting between the ends on one side of the intersecting portion 87a, and a second straight portion 87c connecting between the ends on the other side. You may form so that it may consist of. Here, the first straight portion 87b and the second straight portion 87c are formed so as to be substantially parallel to the central axis of the roller body 16, and the intersecting portion 87a is orthogonal to the first straight portion 87b and the second straight portion 87c. That is, it is formed so as to be orthogonal to the central axis of the roller body 16. Further, the second straight portion 87c is formed shorter than the first straight portion 87b.

  In the case of forming the joint 87 having such a configuration, in particular, the distance d3 between the pair of end portions facing each other in the second straight line portion 87c is the distance between the pair of end portions facing each other in the first straight line portion 87b. It is preferable to form it longer than d4. Note that the distances d3 and d4 between the pair of end portions referred to here are both the distances between the end portions in the gap formed on the outer peripheral surface of the roller body 16.

  In this way, the accuracy of the shape and dimensions of the roller main body 16 as the cylindrical hollow pipe can be further increased, and therefore, uneven conveyance due to deformation of the roller main body 16 and the like can be prevented. That is, in the metal plate which is a base material for forming such a roller main body 16, one end portion constituting the second linear portion 87c is between a pair of adjacent intersecting portions 87a and 87a and these end portions. It becomes the convex piece 87d which makes the external shape the 2nd linear part 87c which ties. Therefore, when pressing the metal plate to bring the convex piece 87d close to the opposite end, as shown by a two-dot chain line in FIG. The sheet is not sufficiently bent into a planar shape, and is floated by a dimension t1 with respect to the opposite end, and as a result, a step is formed in the second linear portion 87c. Then, due to this step, the obtained roller main body 16 is likely to be deformed, and it is difficult to obtain good accuracy in terms of shape and dimensions.

Therefore, by making the distance d3 between the ends of the second straight line portion 87c longer than the distance d4 between the ends of the first straight line portion 87b formed longer than the second straight line portion 87c, FIG. As shown by the solid line in (b), the dimension t2 of the floating side of the tip of the convex piece 87d is smaller (smaller) than the above-described t1, so that a step is formed in the second linear portion 87c. Can be suppressed.
In FIG. 26B, the dimension t2 is also shown large for easy understanding, but actually the dimension t2 is almost close to zero and there is no substantial step. That is, by suppressing the formation of a step in the second linear portion 87c in this way, it is possible to suppress deformation or the like of the roller body 16 due to the step and improve the accuracy of the shape and dimensions.

Further, as shown in FIG. 25C, when the bent portions 85 are formed only at both ends of the roller body 16, as shown in FIG. 27, the intersecting portion 87a (straight portion 85b) in the bent portion 85 is formed. It is preferable that the distance d5 between the pair of end portions facing each other is shorter than the distance d6 between the pair of end portions facing each other at the central straight portion 86.
In this way, the distance d5 becomes relatively short and the gap between the end portions in the intersecting portion 87a becomes very narrow. Therefore, when the metal plate serving as the base material for forming the roller body 16 is pressed The displacement in the length direction (axial direction) between the one end and the other end is regulated by the pair of opposing ends constituting the intersecting portion 87a. Accordingly, the obtained roller main body 16 (conveying roller 15) is less likely to be distorted or twisted, and conveyance unevenness due to such distortion or twist is prevented.

  In addition, as shown in FIG.25 (c), when the bending part 85 is formed only in the both ends of the roller main body 16, the convex piece 87d of this bending part 85 is comprised as shown in FIG. The distance d7 between the pair of end portions facing each other in the second straight line portion 87c may be shorter or longer than the distance d6 between the pair of end portions facing each other in the central straight line portion 86. Good.

  If the distance d7 is formed shorter than the distance d6, the gap formed between a pair of opposing ends can be more easily uniformed when the full length of the joint is viewed. The shape and dimensions of the roller body 16 obtained thereby The accuracy of will be higher. That is, the length of the central straight line portion 86 is longer than the length of the second straight line portion 87c in the bent portion 85, and therefore, the distance between the pair of end portions in the central straight line portion 86 is more accurate than the second straight line portion 87c. Can be close. Therefore, the distance between the pair of end portions of the central straight portion 86 that can relatively improve the accuracy between the end portions is made longer than that of the second straight portion 87c to increase the gap. However, this gap can be made sufficiently uniform, and therefore, uneven conveyance due to distortion or twist of the obtained roller body 16 is prevented.

  On the other hand, if the distance d7 is formed longer than the distance d6, as shown in FIG. 26 (b), the dimension t2 of the floating portion of the tip end of the convex piece 87d is reduced (smaller), thereby causing a step in the second straight portion 87c. Is suppressed from forming. Therefore, the formation of a step in the second linear portion 87c is suppressed in this way, so that deformation of the roller body 16 due to the step is suppressed, and the accuracy of shape and dimensions is increased, thereby causing uneven conveyance. Is prevented.

  In the embodiment, the transport roller according to the present invention is configured to be applied to the transport roller 31 in the transport roller mechanism 19, but may be configured to be applied to the paper discharge roller 41 or the paper discharge jagged roller 42. Can also be applied to the driven roller 32 (roller 32a) in the transport roller mechanism 19.

  DESCRIPTION OF SYMBOLS 1 ... Printer (printing apparatus), 16 ... Roller main body (cylindrical member), 31 ... Conveyance roller, 41 ... Discharge roller (processing apparatus), 60 ... Metal plate, 73, 74, 75 ... Engagement part (positioning part) 86 ... Central straight portion 106 ... Upper die (press die), 106m, 106n ... Press pin (shaft member), 107 ... Lower die (press die), 107m, 107n ... Press pin (shaft member) 120 ... straightening roller, 120A ... straightening roller (first straightening roller), 120B ... straightening roller (second straightening roller)

Claims (10)

A method of manufacturing a conveyance roller for conveying a recording medium,
A first step of bending a plate material to form a substantially cylindrical cylindrical member and forming a positioning portion having a notch shape at an end of the cylindrical member;
A shaft generated in the cylindrical member in the first step by applying a bending load to a predetermined portion of the cylindrical member in a state where the cylindrical member is supported on the center side of the positioning portion in the length direction of the cylindrical member. And a second step of correcting the bending. In the manufacturing method of the conveyance roller of Claim 1,
A method for manufacturing a transport roller, wherein the cylindrical member is supported at a position other than a transport region in contact with the recording medium and transported in the cylindrical member. In the manufacturing method of the conveyance roller of Claim 1 or 2,
A method of manufacturing a transport roller, wherein the bending load is applied to a position other than a transport region in contact with the recording medium and transported in the cylindrical member. In the manufacturing method of the conveyance roller as described in any one of Claim 1 to 3,
In the second step, the bending load is applied to a joint between a pair of end portions obtained by bending the plate material. In the manufacturing method of the conveyance roller as described in any one of Claim 1 to 4,
The second step is a bending forming step of applying a bending load to a predetermined portion of the cylindrical member to form a bending in a direction opposite to the direction of the axial bending generated in the cylindrical member in the first step;
The manufacturing method of the conveyance roller characterized by including the reverse load provision process which provides a bending load to the predetermined location of the said cylindrical member in the reverse direction to the direction which provided the said bending load in the said bending formation process. In the manufacturing method of the conveyance roller as described in any one of Claim 1 to 5,
The predetermined portion of the cylindrical member is located between the plurality of first pressing positions arranged at intervals in the length direction of the cylindrical member, and the plurality of first pressing positions in the length direction, and The manufacturing method of the conveyance roller characterized by including the several 2nd press position facing the said 1st press position in the radial direction of a cylindrical member. In the manufacturing method of the conveyance roller as described in any one of Claim 1 to 6,
In the first step, the plate member is bent using a press mold to form the cylindrical member,
In the second step, a bending roller is applied to a predetermined portion of the cylindrical member by a shaft-like member provided on the press die so as to freely advance and retract. In the manufacturing method of the conveyance roller as described in any one of Claim 1 to 7,
A method for manufacturing a transport roller, comprising a third step of polishing the surface of the cylindrical member after the second step.   A transport unit comprising a transport roller manufactured by the manufacturing method according to claim 1.   A printing apparatus comprising a transport roller manufactured by the manufacturing method according to claim 1.

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