JP5672758B2 - Printing device - Google Patents

Description

  The present invention relates to 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 the printing apparatus is provided with a conveyance unit that conveys the recording medium. Since the conveyance unit affects the printing accuracy of the printing apparatus, a configuration having high conveyance accuracy is required. The transport unit has a transport roller that transports the recording medium by rotating. A solid bar-like member is generally used for the transport roller (see, for example, Patent Document 1).

Japanese Patent No. 3271848

However, the solid conveyance roller as described above has a problem that it is heavy.
In view of the circumstances as described above, an object of the present invention is to provide a printing apparatus having a lightweight conveyance roller.

The printing apparatus according to the present invention includes a drive unit and a cylindrical shaft having end faces that face each other and form a joint, and are in contact with the transport roller driven by the drive unit and the transport medium in the transport roller. A high friction layer provided on the outer periphery of the cylindrical shaft; and a printing unit that performs a printing process on the transport medium transported by the transport roller, and the joint is in contact with the outer peripheral surface side of the cylindrical shaft among end surfaces. and, as a state in which the inner peripheral surface side of the cylindrical shaft is separated out of the end face, and an end surface is formed.
In addition, the drive unit includes a cylindrical shaft provided with end faces that face each other and form a joint, and is provided on the outer periphery of the transport roller driven by the drive unit and the cylindrical shaft in contact with the transport medium in the transport roller. A high friction layer and a printing unit that performs a printing process on the transport medium transported by the transport roller, and the joint is formed so as to straddle the high friction layer, and the joint is formed of the joint. An opening penetrating the inside and outside of the cylindrical shaft is formed at a position away from the high friction layer.
In addition, the drive unit includes a cylindrical shaft provided with end faces that face each other and form a joint, and is provided on the outer periphery of the transport roller driven by the drive unit and the cylindrical shaft in contact with the transport medium in the transport roller. And a printing unit that performs a printing process on the transport medium transported by the transport roller, and the cylindrical shaft has a thickness at the joint smaller than a thickness at other portions. It is characterized by being formed.
Further, a pair of opposite ends of the metal plate are formed in a cylindrical shape so as to approach or contact each other, and a high friction layer for transporting a transport medium is transported by the transport roller and the transport roller. And a printing unit that performs a printing process on the transport medium.

  According to such a structure, since a conveyance roller is formed in a cylindrical shape, the weight reduction of a conveyance roller can be achieved with respect to the case where a solid conveyance roller is used. Thereby, a lightweight printing apparatus can be provided. Moreover, the cost of a conveyance roller can be reduced by forming in a cylindrical shape. Further, since the high friction layer for transporting the transport medium is provided on the outer peripheral surface, high transport accuracy can be ensured and high print accuracy can be secured.

In the printing apparatus, the transport roller has a joint that joins the pair of end portions.
According to such a structure, position shift of a pair of edge part can be prevented with a joint. Thereby, since a deformation | transformation of a conveyance roller can be suppressed, a high conveyance precision is securable.

In the above-described printing apparatus, the joint has a linear portion formed in parallel to the central axis direction of the transport roller.
According to such a configuration, since the joint has the straight portion formed in parallel to the central axis direction of the transport roller, it is possible to prevent the positional deviation between the pair of end portions in the straight portion.

Said printing apparatus has the cross | intersection part formed in the direction which the said joint cross | intersects the center axis direction of the said conveyance roller, It is characterized by the above-mentioned.
According to such a configuration, since the joint has the intersecting portion formed in the direction intersecting the central axis direction of the transport roller, it is possible to prevent the positional deviation between the pair of end portions at the intersecting portion.

In the above printing apparatus, the joint has an inclined portion formed in a direction inclined with respect to a central axis direction of the transport roller.
According to such a configuration, since the joint has the inclined portion formed in the direction inclined with respect to the central axis direction of the transport roller, it is possible to prevent the positional deviation between the pair of end portions in the inclined portion.

The printing apparatus is characterized in that the joint has a curved portion formed by bending.
According to such a configuration, since the joint has a curved portion formed by bending, it is possible to prevent the positional deviation of the pair of end portions in the curved portion.

In the printing apparatus, the joint is in a state in which the outer peripheral surface side of the transport roller is in contact with the pair of end portions and the inner peripheral surface side of the transport roller is separated from the pair of end portions. The pair of end portions are arranged.
According to such a configuration, the pair of end portions are in contact with each other on the outer peripheral surface side of the transport roller, and the inner peripheral surface side of the transport roller is separated from the pair of end portions. Since it is arrange | positioned, the smoothness by the side of an outer peripheral surface will improve in a joint. For this reason, even if a conveyance roller rotates, the outer peripheral surface can contact a conveyance medium stably. For this reason, a conveyance medium can be conveyed with high precision.

In the printing apparatus, the joint is formed so as to straddle the high friction layer, and an opening that penetrates the inside and outside of the transport roller is formed at a position of the joint that is separated from the high friction layer. It is characterized by being.
According to such a configuration, the joint is formed so as to straddle the high friction layer, and an opening penetrating the inside and outside of the transport roller is formed at a position of the joint that is separated from the high friction layer. Therefore, for example, it is possible to prevent foreign matters moving from the end side of the transport roller through the joint from reaching the high friction layer. Thereby, the fall of the conveyance precision of a high friction layer can be avoided.

In the printing apparatus, the transport roller is formed so that the thickness at the joint is smaller than the thickness at the other portion.
According to such a configuration, since the thickness at the joint of the transport roller is formed to be smaller than the thickness at the other part, the internal stress at the joint of the transport roller is adjusted. Can do. Thereby, the curvature of the conveyance roller by progress of time can be reduced.

In the printing apparatus, the high friction layer includes at least one of inorganic particles and organic particles, and an average particle diameter of the particles is larger than a distance between the pair of end portions in the joint. Features.
According to such a configuration, the high friction layer includes at least one of inorganic particles and organic particles, and the average particle diameter of the particles is larger than the distance between the pair of end portions at the joint. A high friction layer can be formed even inside the eye.

In the above-described printing apparatus, the joint includes a plurality of intersecting portions extending in a direction intersecting with a rotation axis direction of the transport roller and an end portion on one side of a pair of adjacent intersecting portions. A pair of adjacent ends of the pair of adjacent crossing portions and a second straight portion that is shorter than the first straight portion, and the pair of ends of the first straight portion. The distance between the parts is shorter than the distance between the pair of end parts in the second straight line part.
According to such a configuration, the joint formed between the pair of end portions is formed in a straight line substantially parallel to the rotation axis direction at the central portion in the rotation axis direction of the transport roller. Since the bent portions are formed only on both sides of the central straight portion formed in the shape, fitting due to unevenness is eliminated at the central straight portion of the joint. Therefore, compared to the case where the concavity and convexity are formed over the entire length of the joint, distortion and twisting are less likely to occur in the transport roller, and good accuracy in terms of shape and dimensions, such as roundness and runout, is obtained. It becomes easy. Moreover, since the distance between a pair of edge part in a center part is formed shorter than the distance between the said pair of edge part in a 2nd linear part, the precision about the shape and dimension of a conveyance roller becomes higher.

  Moreover, one edge part which comprises the 2nd straight line part in a bending part becomes a convex piece which makes an external shape the 2nd straight line part which connects between a pair of adjacent crossing parts, and these edge parts. Therefore, when pressing the convex piece to make it approach or abut against the opposite end, the convex piece is not bent sufficiently in the shape of the circumferential surface and the opposite end is As a result, a step is formed in the second straight portion. Then, due to this level difference, deformation or the like is likely to occur in the obtained conveyance roller, and it becomes difficult to obtain good accuracy in terms of shape and dimensions. Therefore, by making the distance between the end portions of the second straight line portion longer than the central straight line portion, the floating on the tip side of the convex piece is reduced, thereby suppressing the formation of a step in the second straight line portion. Can do. That is, by suppressing the formation of a step in the second linear portion in this way, it is possible to suppress the deformation of the transport roller due to the step and to increase the accuracy of the shape and dimensions. In addition, since the first straight portion is formed longer than the second straight portion, a pair of opposite ends facing the entire length of the joint are brought into close contact with each other or brought into contact with each other when pressed. It becomes possible.

In the above-described printing apparatus, the joint is provided at a central portion in the rotation axis direction of the transport roller, and is formed on a straight line portion formed in a straight line substantially parallel to the rotation axis direction and on both sides of the central portion. A plurality of intersecting portions extending in a direction intersecting with the rotation axis direction, a first straight portion connecting between ends on one side of the pair of adjacent intersecting portions, and the pair of intersecting portions A second straight portion that is shorter than the first straight portion and connects between the other end portions, and the distance between the pair of end portions in the central portion is the pair of the second straight portions. It is characterized by being shorter than the distance between the ends.
According to such a configuration, the joint formed between the pair of end portions is formed in a straight line substantially parallel to the rotation axis direction at the central portion in the rotation axis direction of the transport roller. Since the bent portions are formed only on both sides of the central straight portion formed in the shape, fitting due to unevenness is eliminated at the central straight portion of the joint. Therefore, compared to the case where the concavity and convexity are formed over the entire length of the joint, distortion and twisting are less likely to occur in the transport roller, and good accuracy in terms of shape and dimensions, such as roundness and runout, is obtained. It becomes easy. In addition, since the distance between the pair of end portions in the central portion is shorter than the distance between the pair of end portions in the second straight line portion, the accuracy with respect to the shape and dimensions of the transport roller becomes higher. .

  That is, one end portion constituting the second straight portion in the bent portion is a convex piece having an outer shape of a pair of adjacent intersecting portions and a second straight portion connecting these end portions. Therefore, when pressing the convex piece to make it approach or abut against the opposite end, the convex piece is not bent sufficiently in the shape of the circumferential surface and the opposite end is As a result, a step is formed in the second straight portion. Then, due to this level difference, deformation or the like is likely to occur in the obtained conveyance roller, and it becomes difficult to obtain good accuracy in terms of shape and dimensions. Therefore, by making the distance between the end portions of the second straight line portion longer than the central straight line portion, the floating on the tip side of the convex piece is reduced, thereby suppressing the formation of a step in the second straight line portion. be able to. That is, by suppressing the formation of a step in the second linear portion in this way, it is possible to suppress the deformation of the transport roller due to the step and to increase the accuracy of the shape and dimensions. In addition, since the first straight portion is formed longer than the second straight portion, a pair of opposite ends facing the entire length of the joint are brought into close contact with each other or brought into contact with each other when pressed. It becomes possible.

Said printing apparatus has the to-be-connected part connected to the drive part to which the said conveyance roller rotates the said conveyance roller, It is characterized by the above-mentioned.
According to such a structure, since a conveyance roller has a to-be-connected part connected to the drive part which rotates the said conveyance roller, a conveyance roller can be rotated smoothly. Thereby, high conveyance accuracy can be maintained.

In the printing apparatus, the connected portion is provided at an end portion of the transport roller.
According to such a structure, since the to-be-connected part is provided in the edge part of the conveyance roller, it can be connected to a drive part in an edge part.

In the above-described printing apparatus, the connected portion includes a cutout portion formed by cutting out a part in the circumferential direction of the transport roller.
According to such a configuration, since the connected portion has the cutout portion formed by cutting out a part in the circumferential direction of the transport roller, the drive portion is engaged with the cutout portion. Can be connected. Thereby, the idling of a drive part can be prevented.

In the above-described printing apparatus, the transport roller has a joint that joins the pair of end portions, and the cutout portion is provided at a portion that is separated from the joint in the circumferential direction of the transport roller. It is characterized by being.
According to such a configuration, the transport roller has a joint that joins between the pair of end portions, and the notch portion is provided in a portion that is separated from the joint in the circumferential direction of the transport roller. Even when the urging force around the central axis is applied to the notch, the urging force does not act so as to separate the pair of end portions at the joint. Thereby, it can prevent that a pair of edge part leaves | separates mutually.

In the above printing apparatus, the transport roller includes a connection portion where a pair of end portions of the metal plate are in contact with each other, a second notch portion formed on the outer peripheral surface and provided at a non-arrangement position of the connection portion, It is characterized by having.
According to such a configuration, since the connection portion and the second notch portion in the transport roller are provided apart from each other, even when an urging force around the axis is applied to the second notch portion, This urging force does not act so as to separate the pair of end portions of the connection portion from each other, and the pair of end portions does not separate from each other.

In the printing apparatus, the transport roller has a transport area for transporting the transport medium, is provided on one end side of the transport roller with respect to the transport area, and transmits a rotational driving force to the transport roller. The apparatus further includes a drive member and a second drive member that transmits the transmitted rotational driving force to a processing device that performs processing related to printing.
According to such a configuration, since the first drive member and the second drive member that apply torque to the transport roller are both provided on one end side of the transport region, a large torque is applied to the transport region of the transport roller. Don't join. For this reason, it is possible to prevent the connection between the conveyance regions of the conveyance roller from being shifted, and the conveyance accuracy and thus the printing accuracy from being lowered.

1 is a side sectional view of an ink jet printer according to the present invention. (A) is a top view of a conveyance unit part, (b) is a side view of a drive system. (A) (b) It is a schematic block diagram of a conveyance roller mechanism. It is a schematic block diagram of the manufacturing apparatus of the conveyance roller which concerns on this embodiment. It is process sectional drawing of the extraction process which concerns on this embodiment. It is process sectional drawing of a forging process same as the above. It is a top view of the metal plate after the forge process which concerns on this embodiment. (A)-(c) is process drawing of the bending process which concerns on this embodiment. (A)-(c) is process drawing of the bending process which concerns on this embodiment. (A) is a process diagram of spot welding, (b) is a process diagram of centerless polishing. (A) The perspective view of a roller main body, (b) is a sectional side view of a joint. (A)-(c) is a figure which shows the formation process of the high friction layer to a roller main body. It is a schematic block diagram of the coating booth for forming a high friction layer. It is 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) and (b) are the schematic which shows the structure of a roller main body. It is a principal part perspective view of a roller main body. It is a side view of a roller main body. The principal part top view (a, c, e) of a roller main body, the principal part perspective view (b, d, e). (A)-(d) is a principal part top view of the metal plate which shows an expansion | deployment engaging part. (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. (A) is a figure which shows the joint of a roller main body, (b) is a top view of a metal plate. (A) is a figure which shows the joint of a roller main body, (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. It is a figure for demonstrating the shape of a joint. (A)-(c) is a figure for demonstrating the shape of a joint. It is a schematic block diagram of a roller main body. It is a figure which shows the joint of a roller main body. (A) And (b) is process drawing of spot welding. It is a figure which shows the modification of a roller main body. It is a figure which shows the manufacturing process of a roller main body. It is a figure which shows the manufacturing process of a roller main body. It is a figure which shows the manufacturing process of a roller main body. It is a figure which shows the manufacturing process of a roller main body. The figure which shows the modification of a roller body The figure which shows the modification of a roller body It is a figure which shows the manufacturing process of a roller main body. It is a flowchart which shows the manufacturing process of a conveyance roller. It is a top view of a conveyance unit part. It is a principal part perspective view of a roller main body.

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 sheets (medium, recording medium, transport medium) P are stacked on the paper feed tray 11. Here, as the paper P, plain paper, coated paper, OHP (overhead projector) sheet, glossy paper, glossy film, or the like is used. Hereinafter, in the transport path of the 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 pinch the paper P located at the uppermost part of the paper feed tray 11 with an opposing separation pad (not shown) and send the paper P downstream. 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 transport roller 15 is provided so that the paper P is sandwiched between it and the driven roller 17 and is rotationally driven by the drive unit 30 shown in FIG. As a result, the transport roller 15 can transport the paper P to the print head (printing unit) 21 disposed on the downstream side by a precise and accurate transport (paper feed) operation accompanying the transport printing process. ing.

  The print 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 (paper P transport direction). Printing processing (printing processing) by the print head 21 is controlled by the control unit CONT. A platen 24 is disposed at a position facing the print 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 paper P from below when printing on the paper P by the print head 21, and the top surface functions as a support surface. The distance between the diamond rib 25 and the print head 21 can be adjusted according to the thickness of the paper P.
As a result, the 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 print 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 paper P is pulled out by the rotation of the paper discharge roller 27 and discharged. Yes.
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.

  The transport roller 15 is provided with an inner gear 39 coaxially with the transport drive gear 35, and an intermediate gear 41 is engaged with the inner gear 39. The intermediate gear 41 has a paper discharge drive gear 43. Are in mesh. 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 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 paper P, the paper transport speed is independent of the paper discharge speed of the paper discharge roller mechanism 29 and is transported by the transport roller mechanism 19. It is specified by speed.

Next, the conveyance roller 15 and the conveyance roller mechanism 19 provided with the same will be described.
FIG. 3A is a diagram illustrating a schematic configuration of the transport roller mechanism 19, and FIG. 3B is a diagram illustrating a schematic configuration of the bearing.
The transport roller 15 includes a hollow cylindrical roller body 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).

  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 a cylindrical shaft formed in a cylindrical shape that 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 surface that is on the inner peripheral surface side of the coil is an inner peripheral surface. is there. 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.

  Further, the roller body 16 has a seam 80 formed between a pair of end faces 61a and 61b of a metal plate which is bent and abutted as shown in FIGS. 9 (a) and 9 (b). . In the roller body 16 of the present embodiment, the circumferential direction (bending direction) and the coil winding direction (metal plate rolling direction) are the same, and the seam 80 is substantially parallel to the axial direction of the roller body 16. Is formed.

  As shown in FIG. 3A, the high friction layer 50 is selectively formed in a central portion excluding both ends of the roller body 16. 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.

The high friction layer 50 is formed by selectively applying resin particles with a uniform film thickness of, for example, about 10 μm to 30 μm to the formation region of the high friction layer on the surface of the roller body 16. Inorganic particles and organic particles (for example, resin particles) are uniformly dispersed and then fired. As the resin particles, fine particles having a diameter of about 10 to 20 μm made of, for example, 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.

  As shown in FIG. 3A, both ends of the transport roller 15 are rotatably held by a bearing 26 integrally formed with the platen 24 (see FIG. 1). As shown in FIG. 3 (b), the bearing 26 is formed in a U-shape that opens upward, and the conveyance roller 15 is fitted into this U-shaped portion so that the conveyance roller 15 is moved in the three directions of the front and rear sides and the lower side. From the pivot. Then, lubricating oil (lubricating liquid) such as grease is supplied (applied) to the contact surface between the bearing 26 and the transport roller 15 (the surface of the transport roller 15). Further, an engaging portion (not shown) for engaging and connecting the inner gear 39 and the transport driving gear 35 so as not to rotate is formed at one or both ends of the transport roller 15. Since the transport roller 15 is connected to various connecting parts, various forms of engaging portions can be formed.

  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 paper P), and rotates following the rotation operation of the transport roller 15. Moreover, the force which clamps the paper P between the conveyance roller 15 and the driven roller 17 becomes large, and the conveyance property of the paper P becomes more favorable.

Note that the surface of each roller 17a of the driven roller 17 is subjected to a low wear treatment such as a fluororesin coating in order to alleviate damage due to sliding contact with the high friction layer 50.
The conveyance roller 15, the bearing 26, the drive unit 30, the driven roller 17, and the like described above constitute a conveyance unit (conveyance device) 20 of the inkjet printer 1.

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

  Since the conveyance speed of the paper discharge roller mechanism 29 is set faster than the conveyance speed of the conveyance roller mechanism 19, the 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 paper P, the paper transport speed 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 simultaneously perform paper discharge and transport in this way, the transport speed of the 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 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. 8) 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 paper P, and transport unevenness occurs.

  However, in the present embodiment, the roller main body 16 of the transport roller 15 is formed of a metal plate that is still wound by a steel plate coil, 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 of the roller body 16. Therefore, it is possible to make it difficult to open the seam of the roller body 16 as compared with the case where the winding around the outer peripheral surface side of the roller body 16 remains. That is, according to the present embodiment, even when stress is applied in the direction of opening the seam of the roller body 16, it is possible to prevent the seam from opening and to provide the transport roller 15 that can obtain high transport accuracy. can do.

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 which forms the roller main body 16 acts in the direction which closes the joint of the roller main body 16.
Therefore, the joint of the roller body 16 can be prevented more effectively.

  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 paper P between the transport roller 15 and the driven roller 17 is increased, and the transportability of the paper P is improved.

  Moreover, the conveyance part 20 of this embodiment is provided with the conveyance roller 15 and the bearing 26 which supports this. Therefore, as described above, the transport roller 15 that can obtain high transport accuracy can be supported and rotated by the bearing 26, and the paper P can be supported by the high friction layer 50 and transported with high accuracy. In addition, by adopting the hollow roller body 16 as the transport roller 15, the weight of the transport unit 20 can be greatly reduced compared to the case of using a solid shaft, and the environmental load can be reduced.

  Further, the inkjet printer 1 of the present embodiment can transport the paper P with high accuracy by the transport unit 20 and can perform printing processing on the paper P with high printing accuracy. Further, by adopting the hollow roller body 16 as the transport roller 15, the weight of the entire apparatus can be greatly reduced as compared with the case where a solid shaft is used, and the environmental load can be reduced.

Next, the manufacturing apparatus of the conveyance roller 15 is demonstrated.
FIG. 4 is a schematic view of a manufacturing apparatus for the transport roller 15 according to the present embodiment.
As shown in FIG. 4, 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, for example, a coil C 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 is prepared. 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, for example, a metal plate M die-cut by a punching process as shown in FIGS. 5A and 5B is formed as a base material. That is, the metal plate M 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.

  In this case, even in the case where sagging sd, shear surface sp, fracture surface bs, and burr (not shown) are formed on the metal plate M that has been die-cut as shown in FIG. It is preferable that the upper surface C <b> 2 on which the sagging sd is formed be 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 a joint 80 (refer FIG.8 (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.

  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. Of course, the configuration is not limited to the above, and other configurations may be used.

FIG. 6 is a plan view of the metal plate M punched by the first press machine 130.
As shown in FIG. 6, the metal plate M is punched into a frame portion 66 that is continuous in the transport direction (rolling direction), a strip-shaped flat plate portion 60 that extends in a direction crossing the transport direction, and a 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. 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 transported by a transport unit (not shown) and reaches the second press machine 140 shown in FIG.
FIG. 7A to FIG. 7C and FIG. 8A to FIG. 8C are side views showing a bending process by the second press machine 140.

  The flat plate portion 60 of the metal plate M that has reached the second pressing 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 FIGS. 7A to 7C and FIGS. 8A to 8C, 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. 7A, 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. 7B, 7C, and 8A to 8C 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. 7) which is the inner peripheral side in the coil C shown in FIG. Moreover, the female die 141 is disposed so as to face the surface C2 (the upper surface of the flat plate portion 60 in FIG. 7) which is the outer peripheral side in the coil C shown in FIG. Thereby, both side parts 62a and 62b of the flat plate part 60 are bent to the surface C1 side which was 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. 7C, as shown in FIG. 8A to FIG. 8C, the end faces 61a of both side portions 62a and 62b of the flat plate portion 60. , 61b are brought close to each other.

  Here, the outer diameter of the core die 147 shown in FIGS. 7C and 8A to 8C is equal to the inner diameter of the hollow cylindrical roller body 16 to be formed. Further, as shown in FIG. 7C, 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 equal to the radius of the outer diameter of the roller body 16 considering the polishing margin. It is. Further, as shown in FIGS. 8A to 8C, 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. 7 (c), as shown in FIG. 8 (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) as in 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. Also good.

  Next, as shown in FIG. 8B, 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. 8C, 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 C1 which was the inner peripheral side of the coil C shown in FIG. 4 is the inner peripheral surface of the roller body 16, and C2 which was the outer peripheral surface of the coil C is the outer peripheral surface of the roller body 16. . Thus, the roller body 16 is formed so that the flat plate portion 60 is wound around the core die 147.

FIG. 9 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. 7 (a) to 7 (c) and FIGS. 8 (a) to 8 (c). It is a top view.
The metal plate M punched out as shown in FIG. 6 reaches the second press machine 140 shown in FIG. 4 and is intermittently sent in one direction, while FIGS. 7 (a) to 7 (c), 8A to 8C, the flat plate portion 60 is sequentially bent by a press (a progressive press process). Therefore, as shown in FIG. 9, 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.

  Next, in this embodiment, a centerless polishing process is performed in order to increase the roundness of the formed roller body 16 and reduce the runout. In this polishing step, for example, as shown in FIG. 10, the outer peripheral surface 16a of the roller body 16 is polished using a grindstone member GD formed in a columnar shape (or cylindrical shape).

  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, for example. 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, at the time of rotation of the grindstone member GD, in order to ensure a margin in the longitudinal direction of the roller main body 16, for example, at the central portion in the longitudinal direction of the grindstone member GD, for example, the entire longitudinal direction is in contact with the two grindstone members GD. It is preferable to arrange the roller body 16.

  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.

  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.

  Next, the roller body 16 is plated (plating process). By this plating process, a plating layer is formed on the inner and outer peripheral surfaces and end surfaces 61a and 61b of the roller body 61. Note that even if a steel plate with a pre-plated layer, such as SECC, is used, the end surfaces 61a and 61b are exposed to the base material of the steel plate by punching and are easily corroded, so the end surfaces 61a and 61b It is necessary to form a sufficient plating layer by this process. 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 FIG. 3 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.

As inorganic particles, ceramic particles such as aluminum oxide (alumina; Al ₂ O ₃ ), silicon carbide (SiC), silicon dioxide (SiO ₂ ) and the like are preferably used. 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.

  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.

  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.

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. Furthermore, it is preferable that the minimum particle size in the particle size distribution is larger than the shortest distance between the pair of end portions 61a and 61b in the joint 80, for example, 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 main body 16 is disposed in a painting booth (not shown), and the roller main body 16 is set to, for example, a minus (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 FIG. That is, without performing over the entire length of the roller body 16, for example, by masking both end portions with a tape or the like, it is performed only in the central portion excluding the both end portions as shown in FIG. That is, the resin film 51 is selectively formed only in a region corresponding to at least the central portion of the transport roller 15 including the roller body 16 that is in contact with the paper (medium) P to be transported. In FIG. 12A and FIGS. 12B and 12C described later, the seam 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 film thickness of, for example, 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. 13 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, for example, about 100 rpm to 500 rpm. Of course, the roller body 16 may be supported slightly obliquely.

  Further, a corona gun 93 is disposed at the upper portion of the painting 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, for example, about 10 ¹¹ Ω.

  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 moving the corona gun 93 in the left-right direction in FIG. 13, alumina particles 95 with 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.

  Accordingly, the alumina particles 95 are uniformly attached to the surface of the resin film 51 that is not particularly masked. As a result, the roller main body 16 has alumina in the resin film 51 at the center as shown in FIG. The particles (inorganic particles) 95 are dispersed and exposed. 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 paper P, the area occupied by the alumina particles 95 is 20% to 80% with respect to the area of the resin film 51. Is preferred.

  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. For example, a spray gun is used. The application (spreading) method may be used.

  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. 12C, the high friction layer 50 is formed in which the alumina particles (inorganic particles) 95 are dispersed and exposed in the resin film 51, and the transport roller 15 according to the present invention 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. 14, it adheres to the outer peripheral surface of the roller body 16 through 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 main body 16 (conveying roller 15) in the direction of narrowing the gap during use or the like, the alumina particles 95a that have entered here resist this force, so the roller main 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, processing such as cleaning the inside of the roller body 16 is reduced thereafter, and productivity can be improved correspondingly.
Through the above steps, as shown in FIG. 3A, a high friction layer 50 is formed in which the alumina particles are dispersed and exposed in the resin film, and the transport roller 15 is obtained.

  As mentioned above, according to this embodiment, since the conveyance roller 15 is formed in a cylindrical shape, the weight reduction of the conveyance roller 15 can be achieved with respect to the case where a solid conveyance roller is used. Thereby, the lightweight inkjet printer 1 can be provided. Moreover, the cost reduction of the conveyance roller 15 can be achieved by forming in a cylindrical shape. Furthermore, since the high friction layer 50 for transporting the recording paper P as a transport medium is provided on the outer peripheral surface of the transport roller 15 (roller body 16), high transport accuracy can be ensured and high print accuracy can be secured. can do.

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.
For example, in the above-described embodiment, the roller body 16 has a configuration in which a steel plate coil around which a metal plate such as a galvanized steel plate or a stainless steel plate is wound is formed as a base material, but is not limited thereto. No. For example, 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. I do not care. Therefore, for example, in the above description or the following description, the present invention is applicable even when the flat plate portion 60 is replaced with the metal plate.

Further, for example, 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. 15B, the seam 80 formed in 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 bearing 26 adheres to the surface of the transport roller 15, the grease L flows along the seam 80 by capillary action. . 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. 15C, an opening 170 is provided in a part of the seam 80 formed in the roller body 16. As shown in FIG. 15C, 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 surfaces 61a and 61b are brought into contact with each other, the maximum distance d2 between the notches 176 and 177 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 15 (roller body 16). That is, the high friction layer 50 is formed at substantially the center of the transport roller 15, and both ends of the transport roller 15 are supported by the bearings 26, 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 (lubricant) supplied (applied) to the bearing 26 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 supported by the bearing 26 and the region where the high friction layer 50 is formed in the joint 80, the grease L is prevented from reaching the high friction layer 50. ing. 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. 15D, a notch 178 is formed only in one of the pair of end surfaces 61a and 61b (for example, the end surface 61a) forming the joint 80, and the notch 178 and the end surface 61b open. 170 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 joint 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. Moreover, the shape of the 1st end surface 274 and the 2nd end surface 275 becomes the same shape over the full length of the roller main body 271 except the bending part 85. FIG.

  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. 16 (b), 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 271 a 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.16 (c), the inclination with respect to the outer peripheral surface 271a of the 1st end surface 274 and the 2nd end surface 275 is adjusted by press work. 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.

  Further, the configuration shown in FIGS. 16A and 16B may be a configuration in which, for example, a part of the first end surface 274 and a part of the second end surface 275 are in surface contact. For example, the configuration corresponding to FIG. 16A will be described. As shown in FIG. 17A, the first end surface outer edge portion 274a, which is a part of the first end surface 274, and a part of the second end surface 275. The second end surface outer edge 275a may be in surface contact with each other. That is, in the joint 80, there are no gaps, recesses, or the like that open to the outer peripheral surface 271a side. Therefore, the contact between the outer peripheral surface 271a and the recording paper P can always be maintained when the transport roller 15 rotates. Further, since the first end surface outer edge portion 274a and the second end surface outer edge portion 275a are in surface contact with each other, the strength of the roller body 16, particularly the strength near the joint 80 is improved. Even if a bending or twisting force is applied to the roller body 16, the first end surface 274 and the second end surface 275 can be prevented from separating from each other.

  A gap 277 is formed between the first end surface inner edge portion 274b and the second end surface inner edge portion 275b. The gap 277 has a shape that gradually becomes wider toward the inner peripheral surface 271b side. The first angle α1 formed by the first end surface inner edge portion 274b and the inner peripheral surface 271b and the second angle α2 formed by the second end surface inner edge portion 275b and the inner peripheral surface 271b are both greater than 90 °. .

  Further, the configuration corresponding to FIG. 16B will be described. As shown in FIG. 17B, a second gap (gap) 277A is formed between the first end face inner edge portion 274b and the second end face 275. Is formed. The second gap 277A has a shape that gradually becomes wider toward the inner peripheral surface 271b side. The first angle α1 formed by the first end surface inner edge 274b and the inner peripheral surface 271b is greater than 90 °, and the third angle α3 formed by the second end surface 275 and the inner peripheral surface 271b is 90 ° or less. ing. That is, the first end surface 274 (and the second end surface 275) in the joint 80 has a shape inclined in a predetermined direction with respect to the circumferential direction. When the recording paper P is transported by rotating the transport roller 15 in the direction along the inclination, the first end surface 274 and the second end surface 275 are separated even if a biasing force accompanying the transport is applied to the joint 80. Is less likely to occur. Therefore, distortion, deformation, etc. of the transport roller 15 that may occur with transport can be suppressed.

  Further, as described above, one or both of the both ends of the roller body 16 (conveyance roller 15) are connected to various connection components such as the conveyance drive gear 35 and the inner gear 39 shown in FIG. An engaging portion is formed. For example, as shown in FIG. 18 and FIG. 19, through holes are respectively formed in opposing positions of a roller body 16 formed of a cylindrical pipe (hollow pipe), that is, two formation surfaces that define the diameter of the roller body 16. 71a, 71a can be formed, and an engagement hole (engagement portion) 71 including the pair of through holes 71a, 71a can be formed. According to the engagement hole 71, the connecting component 72 such as a gear can be fixed by a shaft, a pin or the like (not shown).

  Further, as shown in FIGS. 20A and 20B, a D-cut engagement portion 73 can be formed at the end of the roller body 16. The engaging portion 73 is formed at the end of a cylindrical hollow pipe (roller body 16). As shown in FIG. 20A, a part of the engaging portion 73 is cut out in a rectangular shape in plan view. As a result, the outer shape of the side surface of the end portion is formed in an apparent D shape as shown in FIG.

  Therefore, by engaging a connecting part (not shown) such as a gear with the engaging portion 73 formed in an apparent D shape, the connecting part is idled with respect to the roller body 16 (conveying roller 15). It can be installed without. 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 part can be connected to the roller body by using the opening 73a. It can be attached to 16 without making it idle. Specifically, by forming a convex portion on the connecting component and fitting the convex portion into the opening 73a, it is possible to prevent idling.

  Further, as shown in FIGS. 20C and 20D, an engaging portion 74 having a groove 74 a and a D cut portion 74 b can be formed at the end of the roller body 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. 20 (c), 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. 20 (d), when the pair of bent pieces 74d and 74d are bent toward the central axis 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.

  Therefore, a connecting part (not shown) such as a gear is engaged with the groove 74a or the D-cut portion 74b without causing the connecting part to idle with respect to the roller body 16 (conveying roller 15). Can be attached. 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.

  In addition, as shown in FIGS. 20E and 20F, an engaging portion 75 having a groove 75a and an opening 75b 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. 20 (e), 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 body 16 is cut out in a rectangular shape in plan view outside the groove 75a, and thereby the outer shape of the end side surface is formed in an apparent D shape as shown in FIG. Is.

  Therefore, 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 connecting the connecting part to the roller body 16. It can be attached to the (conveying roller 15) without idling. Also, in this engaging portion 75, similarly to the engaging portion 73 shown in FIGS. 20 (a) and 20 (b), the connecting component is idled with respect to the roller body 16 by using the opening 75b. Can be installed without.

  In order to form such engagement holes 71 and engagement portions 73, 74, and 75, the roller body 16 obtained by pressing the flat plate portion 60 is further subjected to cutting or the like. You can also. However, in that case, the cost and time efficiency are reduced by adding a separate processing step to the roller body 16 only for forming the engaging portion. Therefore, in the manufacturing method of the present invention, before the roller main body 16 is pressed in the second pressing step, a deployment engaging portion that becomes an engaging portion is formed on the flat plate portion 60 by pressing in the first pressing step. Thereafter, when the flat plate portion 60 is pressed into the roller body 16 in the second pressing step, the engaging portion is simultaneously formed.

  Specifically, when the metal plate M wound in a coil shape is punched into an elongated substantially rectangular plate-shaped flat plate portion 60, the flat plate obtained simultaneously with the processing from the large metal plate M to the small flat plate portion 60. At the end of the portion 60, a development engagement portion such as a notch shape, a protruding piece shape, a hole shape, or a groove shape is formed.

  For example, as shown in FIG. 21 (a), a pair of through holes 71a and 71a are processed at predetermined positions on the end of the flat plate portion 60, and these are used as the deployment engaging portion 76a, thereby pressing the flat plate portion 60. By processing, a pair of through-holes 71a and 71a can be made to oppose, and the engagement hole 71 shown in FIG.18 and FIG.19 can be formed.

  Further, as shown in FIG. 21B, the flat plate portion 60 is pressed by cutting the end portion of the flat plate portion 60 into a predetermined shape to form a deployment engagement portion 73c including a pair of cutout portions 73b and 73b. By processing, the engaging portion 73 shown in FIGS. 20A and 20B can be formed.

  Furthermore, as shown in FIG. 21 (c), the flat plate portion 60 is pressed into a predetermined shape by cutting out the end portion of the flat plate portion 60 into a predetermined shape, thereby pressing the flat plate portion 60 as shown in FIG. 20 (c). And the engaging part 74 shown in FIG.20 (d) 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 flat plate portion 60 is pressed, it is necessary to bend the pair of projecting pieces 74f and 74f inward to form a bent piece 74d. Is slightly insufficient to increase

  Therefore, as shown in FIG. 21 (d), the flat plate portion 60 is pressed into a predetermined shape by cutting the end portion of the flat plate portion 60 into a predetermined shape, thereby pressing the flat plate portion 60 as shown in FIG. And the engaging part 75 shown in FIG.20 (f) 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 flat plate portion 60 is pressed, the pair of projecting pieces 75d and 75d are also bent in an arc shape, thereby forming the opening 75b shown in FIG. 20B between the projecting pieces 75d and 75d. Can do. 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.

  Here, in the example shown in FIGS. 21B to 21D, the engaging portions 73, 74, and 75 shown in FIGS. 20A to 20F are formed with the joint 80 interposed therebetween. The expansion engaging portions 73c, 76b, and 76c are formed at both ends of the flat plate portion 60. Thus, by forming the deployment engaging portions 73c, 76b, and 76c at both ends, the joint 80 of the roller body 16 to be formed can be made shorter than the length of the roller body 16. Therefore, it is possible to suppress deformation of the roller body 16 due to the end surfaces 61a and 61b partially contacting and interfering when the seam 80 is formed.

  However, the present invention is not limited to this, and as shown in FIGS. 22 (a) to 22 (c), the width direction (bending direction) is not formed on the both ends of the flat plate portion 60, as shown in FIG. ) In the vicinity of the center line. That is, as shown in FIG. 22A, the engaging portion 73 shown in FIG. 18 can be formed by forming a deployment engaging portion 76d formed of an elongated rectangular cutout at the end portion. Further, by forming a deployment engagement portion 76e formed of a T-shaped notch as shown in FIG. 22 (b), the engagement portion 74 shown in FIGS. 20 (c) and 20 (d) is formed. Furthermore, by forming a deployment engagement portion 76f having a substantially T-shaped notch as shown in FIG. 22 (c), the engagement shown in FIG. 20 (e) and FIG. 20 (f) is possible. The part 75 can be formed.

  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.

As described above, in the method for manufacturing the transport roller 15 according to the present embodiment, when the small metal plate (first metal plate) 60 is formed from the large metal plate (second metal plate) M by pressing, the unfolding unit is used. The joint portion is also formed at the same time, and when the metal plate (first metal plate) 60 is pressed, the engaging portions 71, 73, 74, 75 are formed from the deployment engaging portion. After forming 16, it is not necessary to add a separate processing step only for forming the engaging portion.
Therefore, since the cost and time required for the added processing steps are not required, the cost of the transport roller 15 itself can be sufficiently reduced, and the productivity is improved. In particular, when the large metal plate is reduced in size, the development engaging portion is formed in a lump so that the process can be further simplified.

  In addition, as shown to Fig.11 (a), in the conveyance roller 15 (roller main body 16) which concerns on this embodiment, the joint 80 is parallel to the central axis of the roller main body 16 which consists of a cylindrical hollow pipe. However, the present invention is not limited to this, for example, a seam formed between a pair of end portions of the flat plate portion 60 serving as a base material on the outer peripheral surface of the cylindrical pipe (roller body), On a straight line parallel to the central axis of the cylindrical pipe, it may be formed so as to overlap only one or a plurality of points without overlapping the straight line with a line segment.

  Specifically, as shown in FIG. 23A, the outer peripheral surface of the roller body 16 extends in the circumferential direction so as to intersect with the seam 81 without being parallel to the central axis 16 c of the roller body 16. However, the roller body 16 may be formed so as to extend from one end to the other end. In order to form the seam 81 in this way, as a base metal plate, instead of the elongated rectangular flat plate portion 60, as shown in FIG. 23B, an elongated parallelogram flat plate portion 60a is formed, Pressing is performed so that the straight line indicated by reference numeral 16d is the central axis. Thereby, the roller main body 16 shown in FIG. 23A is obtained, and the seam 81 is not parallel to the central axis 16c.

  In addition, in the roller main body 16 shown to Fig.23 (a), the seam 81 is formed so that it may rotate from the one end of the roller main body 16 to the other end less than one round. This is to facilitate the press working of the flat plate portion 60a. However, as shown in FIG. 23 (c), the seam 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 such a case, the angle θ in the elongated parallelogram flat plate portion 60a shown in FIG.

  In addition, as shown in FIG. 24A, the seam 83 may be formed in a wavy line composed of a curve such as a sine wave. In order to form the seam 83 in this way, as shown in FIG. 24 (b), a flat plate portion 60b in which both long sides thereof are formed in a wavy shape as a metal plate as a base material as shown in FIG. And press working so that the straight line indicated by reference numeral 16d is the central axis. In addition, since a pair of long sides formed in a wavy line are brought close to each other by pressing, naturally, when one long side becomes a peak portion between corresponding points, a valley is formed on the other long side. Conversely, when one long side is a valley, the other long side is a mountain. In this example, the center line of the joint 83 is formed so as to be parallel to the center axis of the roller body 16, but the center line of the joint 83 is also formed so as not to be parallel to the center axis of the roller body 16. May be. In that case, as the metal plate to be the base material, a long and parallelogram-shaped metal plate as shown in FIG. 23 (b) and both of which long sides are formed in a wavy shape may be used. .

In addition, as shown in FIG. 25A, the seam 84 may be formed in a wavy shape bent in a hook shape. In order to form the seam 84 in this way, as a metal plate as a base material, as shown in FIG. 23 (b), it is formed in a long and narrow rectangular shape, and both long sides thereof are bent in a wavy shape. Using the flat plate portion 60c, the straight line indicated by reference numeral 16d is pressed so as to be the central axis.
Also in the flat plate portion 60c, between the portions corresponding to each other in the pair of long sides formed in a wavy line, when one long side is a peak, the other long side is a valley, and conversely, When the long side is a trough, the other long side is a crest. Also in this example, the center line of the seam 84 is formed so as to be parallel to the center axis of the roller body 16, but similarly to the case of the seam 83, it is formed so as to be non-parallel to the center axis of the roller body 16. May be.

  Further, the seam is not limited to the examples shown in FIGS. 23 to 25, and various shapes can be adopted. For example, the wavy line formed by the curve shown in FIG. 24A and the bent wavy line shown in FIG. 25A may be combined, and these may be combined with an oblique line as shown in FIG. Also good.

  If the seams 81 to 84 are formed so as to overlap only at one or a plurality of points without overlapping in a line segment with respect to a straight line parallel to the central axis of the cylindrical pipe (roller body 16), The transport roller 15 having the roller body 16 has a constant transport speed of the paper P when the paper P is transported in cooperation with the driven roller 17, that is, when the paper is fed, and transport unevenness is more sure. Will be prevented.

  That is, as shown in FIG. 26, the portion where the transport roller 15 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 L parallel to the central axis 16c. Therefore, when the joint 80 of the transport roller 15 (roller body 16) is parallel to the central axis 16c of the roller body 16 as shown in FIG. 7B, the entire joint 80 of the transport roller 15 is temporarily ( (Instantaneously) the sheet P is touched. Then, since the groove is not formed due to the seam 80 in the transport roller 15 of the present embodiment as described above, there is no problem, but if the groove is formed due to the seam 80, 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 seam 80. As a result, the groove has a dent compared to the other outer peripheral surface of the transport roller 15, and the contact resistance with respect to the paper P is small. Therefore, the transport speed of the paper P is temporarily reduced, resulting in uneven transport. End up.

  Therefore, if the seams 81 to 84 are formed as shown in FIGS. 23A, 23C, 24A, and 25A, grooves are formed due to these seams. However, there are only one or a plurality of points where the groove contacts the paper P at the same time when the paper is fed. Therefore, there is almost no change in the contact resistance as compared with the case where the other surface (line) of the transport roller 15 hits, whereby the transport speed of the paper P becomes constant and transport unevenness is prevented.

  In addition to the above-described example, the seam of the transport roller 15 (roller body 16) made of a cylindrical hollow pipe is a straight line parallel to the central axis of the roller body 16 as shown in FIG. It may be formed having a rectangular wave-like bent portion 85 composed of a portion 85a and a linear portion 85b orthogonal thereto. Even in a joint having such a bent portion 85, if a groove is formed due to the joint, the groove simultaneously contacts the entire width of the sheet P during paper feeding. Therefore, the conveyance speed of the paper P becomes almost 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. 27 (b), and the central portion thereof as shown in FIG. 27 (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. 27C, a space between the bent portions 85 forms a central straight portion 86 that is parallel to the central axis of the roller body 16. However, although not shown, the central straight portion between the bent portions 85 may be formed as an oblique line that is not parallel to the central axis 16c 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 shown in FIG. It is preferable to correspond to the portion 86.

  When the bent portion 85 is formed at the joint, and thus the bent portion 85 is formed as a fitting portion by unevenness, the bent portion 85 (fitting portion) is fitted as designed, and the tip of the convex portion is connected to the tip. It becomes difficult to bring them close to each other with no gap between the corresponding recesses. 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. 27C, 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. 27B, when the bent portion 85 is formed over the entire length of the roller body 16, a seam 87 made up of the bent portion 85 as shown in FIG. 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.

  When the seam 87 having such a configuration is formed, in particular, the distance d3 between the pair of end portions facing each other in the second straight line portion 87c is set to be the distance d4 between the pair of end portions facing each other in the first straight line portion 87b. It is preferable to form it longer. 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. 28 (b), the dimension t2 is also shown large for ease of 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.

  In addition, as shown in FIG. 27C, when the bent portion 85 is formed only at both ends of the roller body 16, as shown in FIG. 29, the intersecting portion 87a (straight line 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.27 (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 entire length of the seam is viewed, and the shape and dimensions of the roller body 16 obtained thereby can be obtained. The accuracy is 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. 28 (b), the dimension t2 of the floating portion of the tip end side of the convex piece 87d is reduced (smaller). 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 addition to the above-described example, for the joint of the transport roller 15 (roller body 16) formed of a cylindrical hollow pipe, for example, as shown in FIG. The angle α on the tip end side of the convex piece 88b in the bent portion 88 may be formed to be an obtuse angle (less than 180 °) with respect to the central axis of the main body 16. 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 convex piece 88b can be easily fitted into the corresponding concave portion, and therefore the roller body 16 is distorted or twisted. Can be suppressed.

  In addition, in the structure in which the bent portion 85 is formed only at both ends as shown in FIG. 27C, the bent portion 85 is shown in FIG. 24A as shown in FIG. 30B, for example. It may be replaced with a wavy line 89a made of a curve, and further may be replaced with a bent wavy line 89b shown in FIG. 25 (a) as shown in FIG. 30 (c).

  Further, a seam may be formed by combining the rectangular wavy bent portion 85 shown in FIG. 27 (a) and the wavy line 89a made of a curve shown in FIG. 30 (b), or a rectangular wavy bent portion. A seam may be formed by combining 85 and the bent wavy line 89b shown in FIG.

  Moreover, in the roller main body 16 of the said embodiment, as shown, for example to Fig.31 (a), you may make it form the spot welding part SP in the joint 80. FIG. The spot weld SP is formed by, for example, irradiating a laser beam and dissolving a part of the roller body 16 (metal plate). Needless to say, the spot welded portion SP may be formed by a method other than the laser beam irradiation.

  The spot welded portion SP is a welded portion formed in a part of the joint 80, unlike the welding applied to the whole joint 80. FIG. 31 (a) shows a state in which a substantially circular region is formed, but the shape is not necessarily limited to this. For example, a configuration in which the seam 80 is slightly expanded in the formation direction of the joint 80 (for example, an ellipse) may be used.

  The spot welds SP are provided, for example, at a plurality of positions in the joint 80. For example, as shown in FIG. 31A, the spot welded portion SP is provided at a position closer to the end of the roller body 16 in the rotation axis direction than the position supported by the bearing 26 in the roller body 16. . Further, spot welds SP are also provided at positions between the position supported by the bearing 26 and the position where the high friction layer 50 is formed.

  FIG. 31A shows only one end portion of the both end portions of the roller body 16, but the spot welded portion SP is similarly formed at the other end portion. Further, the spot welded portion SP may be disposed in the vicinity of a portion of the roller body 16 that is connected to the transport drive gear 35 and the inner gear 39. Moreover, when the spot weld part SP is arrange | positioned rather than the bearing 26 at the high friction layer 50 side, it is preferable to arrange | position in the part removed from the part pressed by the driven roller 17, for example.

  Such a process of forming the spot weld SP (spot welding process) can be performed, for example, after the progressive press process and before the centerless polishing process. In this case, spot welding is performed on the joint 80 of the roller body 16 formed by the progressive press process. A welding process is performed in order to raise the intensity | strength of the joint 80 in the said spot weld part SP by forming the spot weld part SP in the joint 80. FIG. In this configuration, for example, as shown in FIG. 31B, laser light L is emitted from the laser irradiation device LA to the spot forming area SA, and the spot forming area SA is melted.

  In the spot forming region SA, a part of the molten metal plate M is solidified in a state where the end portions 61a and 61b of the metal plate M are connected, and the spot welded portion SP is formed. In the present embodiment, an example in which a part of the metal plate M is melted by irradiating the laser beam L is shown, but the present invention is not limited to this. For example, the metal plate M may be melted (for example, heat is applied) by other methods.

  In addition, after this spot welding process, you may make it perform a rough centerless process with respect to the roller main body 16, for example. The rough centerless process is a polishing process that is simpler than, for example, the centerless polishing process in the above embodiment. In the rough centerless process, for example, the processing time is shorter than that in the centerless polishing process. Moreover, the grindstone member used in the rough centerless process may not have the polishing ability as much as the grindstone member GD used in the centerless polishing process.

Moreover, the example regarding the spot welding part SP is described below.
In the above-described embodiment, an example in which the spot welded portion SP is formed on the roller body 16 in which the joint 80 is formed in a straight line has been described, but the present invention is not limited to this. For example, in addition to the linear joint 80, the spot welded portion SP can be suitably formed, for example, for each joint 80 described above.

  Further, for example, as shown in FIG. 32, in the roller body 16 of the transport roller 15 in which the connection portion 73D with the rotation drive unit is formed at the end, the spot welded portion SP is in the vicinity of the connection portion 73D (for example, connection A configuration provided between the portion 73D and the bearing 26 is preferable.

  In addition, for example, the present invention can be applied even when the uneven portion 110 is formed in the joint 80. As shown in FIG. 32, the concavo-convex part 110 is formed in a rectangular shape so that one end 61a and the other end 61b of the metal plate M are fitted. The concavo-convex portion 110 has, for example, a first side 110 a along the rotation axis direction of the roller body 16 and a pair of second sides 110 b along the circumferential direction of the roller body 16.

  In this case, it is preferable that the spot welded portion SP has, for example, a configuration provided on at least one of the first side 110a and the second side 110b. For example, by forming the spot welded portion SP on the first side 110 a, the concavo-convex portion 110 becomes stronger with respect to the force in the circumferential direction of the roller body 16, for example. For this reason, it can prevent the uneven | corrugated | grooved part 110 from opening in the said circumferential direction, or being depressed inside, for example.

  Moreover, when forming the spot welding part SP in the 2nd edge | side 110b, since it becomes easy to align the formation position, it can form easily. Of course, even when the spot welded portion SP is formed on the second side 110b, the strength can be improved with respect to the circumferential force of the roller body 16. Moreover, it is good also as a structure provided in all the edges of the 1st edge | side 110a and the 2nd edge | side 110b.

  Moreover, you may form spot welding part SP in the boundary part 110c of the linear part 80a of the joint 80, and the uneven | corrugated | grooved part 110. FIG. For example, the boundary portion 110c is easily subjected to a force from the uneven portion 110. For this reason, the deformation | transformation in the uneven | corrugated | grooved part 110 can be prevented more reliably by providing the spot weld part SP and improving the intensity | strength of the boundary part 110c.

  In FIG. 32, the case where the concave and convex portion 110 is disposed between the connection portion 73 </ b> D and the bearing 26 is described as an example, but the present invention is not limited to this configuration. For example, even when the uneven portion 110 is formed on the higher friction layer 50 side than the bearing 26, the spot welded portion SP can be suitably formed on the uneven portion 110 as described above.

  When the metal plate M is formed into a cylindrical shape by pressing, as shown in FIG. 33A, one end 61a and the other end 61b of the metal plate M are on the outer surface 16a side of the roller body 16. It is also possible to form the metal plate M so as to make contact with each other. In this case, as shown in FIG. 33 (b), the spot welded portion SP is formed by applying energy such as laser light from the outer surface 16a side of the roller body 16 to form the spot welded portion SP. The finished state of SP becomes good.

  Moreover, in the said description, although the structure formed so that the connection part formed in the roller main body 16 might be based on the joint 80 was mentioned as an example, it is not restricted to this. For example, as illustrated in FIG. 34, a configuration may be employed in which a cutout portion 73 that is a connected portion is provided at a position (non-arranged position) that deviates from the joint 80. In FIG. 34, the notch 73 is provided at a position facing the joint 80, that is, a position opposite to the joint 80 across the central axis of the roller body 16.

  When the transport roller 15 rotates, an urging force from the third drive gear that works in the direction opposite to the rotation acts on the transport roller 15. On the other hand, according to the above configuration, the first end portion 61a and the second end portion 61b do not act so as to be separated from each other. Thereby, there exists an effect that a deformation | transformation of the roller main body 16 can be prevented.

  In the above description, in the bending process of the progressive press process, the core die 147 disposed inside the flat plate portion 60 has been described as an example of a configuration having a circular cross-sectional view, but the present invention is not limited thereto. .

  FIG. 35A to FIG. 35C and FIG. 36A to FIG. 36C are diagrams showing other examples of the bending process. As shown in FIGS. 35 (a) to 35 (c), the first upper mold (mold) 205, the second upper mold (mold) 206, and the lower mold 207 are substantially C-shaped in cross section. The flat plate portion 60 molded in the above is disposed, and a cylindrical cored bar (core member) 208 is disposed inside the flat plate portion 60.

  The cored bar 208 is a substantially round bar-shaped member. The cored bar 208 has a portion corresponding to the first end 61a and the second end 61b (see FIG. 36C) of the flat plate part 60 when the outer peripheral surface 208a is formed into a cylindrical shape. A notch 208b is provided. The notch 208 b extends in parallel with the axial direction of the core bar 208 and is formed over the entire length of the core bar 208. The notch 208 b has a flat surface 208 c that faces the radially outer side of the core bar 208. Since the flat surface 208c can be easily formed by cutting or the like, the notch 208b can be easily formed at a low cost with respect to the cored bar 208. The notch depth t in the radial direction of the notch 208 b is formed with substantially the same depth over the entire length of the cored bar 208. The notch depth t is set according to the amount of pushing required for the first end portion 61a and the second end portion 61b in the flat plate portion 60.

  The first upper mold 205, the second upper mold 206, and the lower mold 207 include press surfaces 205a, 206a, and 207a that contact the flat plate portion 60 during pressing, respectively. On the press surfaces 205a and 206a, flat portions 205b and 206b formed in a flat shape corresponding to the cutout portions 208b of the cored bar 208 are formed, respectively. The flat portions 205b and 206b are opposed to and substantially parallel to the flat surface 208c of the notch 208b. Note that the first upper mold 205 and the second upper mold 206 are movable independently of each other.

  Next, as shown in FIG. 36A, the first upper die 205 is moved toward the lower die 207 while the cored bar 208 is stationary, and the first end 61a side of the flat plate portion 60 is pressed. And bend into a semi-circular shape. As in the case of the first upper mold 205 and the second upper mold 206, the lower mold 207 is a pair of split molds, and the lower mold on the same side as the first upper mold 205 is used in the process shown in FIG. May be moved toward the first upper mold 205.

  Next, as shown in FIG. 36 (b), the cored bar 208 is moved slightly toward the lower mold 207, and the second upper mold 206 is moved toward the lower mold 207, so that the second end of the flat plate portion 60 is moved. The part 61b side is pressed and bent into a substantially semicircular shape.

  Next, as shown in FIG. 36C, the first upper mold 205, the second upper mold 206, and the cored bar 208 are all moved toward the lower mold 207, and the flat plate portion 60 is pressed. At this time, the first upper mold 205 and the second upper mold 206 are in contact with the lower mold 207. By this pressing, the flat plate portion 60 is formed into a substantially cylindrical shape, and the roller body 16 is formed from the flat plate portion 60.

  Here, a notch 208b is formed in the cored bar 208, and flat portions 205b and 206b are formed in the first upper mold 205 and the second upper mold 206. Therefore, the flat portions 205b and 206b can push the end surfaces 61a and 61b of the flat plate portion 60 and their periphery radially inward. Therefore, when the flat plate portion 60 is formed into a cylindrical shape, it is possible to prevent the end surfaces 61a and 61b and their periphery from expanding outward. Therefore, the roundness of the roller body 16 at the end of the bending process can be improved.

  The end surfaces 61a and 61b and their periphery are pushed inward from the other portions, but the flat plate portion 60 has elasticity and returns (springback) at the end of the bending process. Further, since the notch depth t of the notch 208b is set to a depth that considers the return, the end surfaces 61a and 61b and their surroundings are not pushed too much inward, and the roller at the end of the bending process There is no possibility that the roundness of the main body 16 is reduced.

  In this step, the outer peripheral surface 31a side of the end surfaces 61a and 61b abut against each other without a gap. Furthermore, by pushing the end surfaces 61a and 61b inward, the outer peripheral surface 31a side of the end surfaces 61a and 61b can be more easily brought into contact. In the present embodiment, end face adjustment processing is performed to make the angles formed by the end faces 61a and 61b and the inner peripheral face 31b larger than 90 °, respectively, but the end faces 61a and 61b and their periphery are pushed inward. Thus, when the outer peripheral surface 31a side of the end surfaces 61a and 61b can be brought into contact with each other without a gap, the end surface adjustment processing may not be performed. In addition, the degree of end face adjustment processing can be reduced as compared with the case where no pressing is performed. On the other hand, a gap 277 is formed on the inner peripheral surface 31b side between the end surfaces 61a and 61b.

  Further, in the present embodiment, the first upper mold 205 and the second upper mold 206 are formed with flat portions 205b and 206b, respectively, but the end surfaces 61a and 61b and their surroundings can be formed only by forming the notches 208b. If it can be urged sufficiently inward, the flat portions 205b and 206b need not be formed. Even in this case, the end surfaces 61a and 61b and their periphery are not supported from the cored bar 208 but are pushed inward.

  In addition, since the roller main body 16 (conveyance roller 15) is shape | molded using the large sized metal plate 60 with which the winding by a steel plate coil remained, the surface which was the inner peripheral side of the coil is the inner peripheral surface of the roller main body 16. It is preferable to mold so as to be. That is, the winding of the large 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 large metal plate 60 that forms the roller main body 16 has a winding that warps toward the inner peripheral surface of the roller main body 16.

  Therefore, winding does not act at least in the direction of opening the joint 36 of the roller body 16. 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 15 with high transport accuracy can be obtained.

  Instead of the cored bar 208 described above, a second cored bar (core member) 208A or a third cored bar (core member) 208B, which is a modified example thereof, may be used. A second metal core 208A, which is a first modification of the core metal 208, will be described with reference to FIG. 37, and a third metal core 208B, which is a second modification, will be described with reference to FIG. FIG. 37 is a schematic view showing a first modification of the cored bar, where (a) is a side view, (b) is a sectional view taken along line EE of (a), and (c) is (a). It is a HH line sectional view. 38A and 38B are schematic views showing a second modification of the cored bar, where FIG. 38A is a side view, FIG. 38B is a cross-sectional view taken along the line I-I in FIG. It is a JJ line sectional view.

  First, the second cored bar 208A will be described. In FIG. 37 (a), the conveying roller 15 and the second cored bar 208A are shown side by side for explanation. The second core bar 208A includes a notch 208d in which a portion corresponding to the holding region F of the transport roller 15 on the outer peripheral surface 208a is notched. The notch 208d is formed in a range that is substantially parallel to the axial direction of the second cored bar 208A and is slightly enlarged from the holding region F to both ends of the transport roller 15. This is because the effect of bending, stress, and the like are made uniform with respect to the holding area F that is an area for holding the recording paper P.

  As shown in FIG. 37B, the cross-sectional shape of the second cored bar 208A corresponding to both ends of the transport roller 15 is substantially circular. As shown in FIG. 37 (c), the cutout portion 208d has a flat surface 208e facing outward in the radial direction. The notch depth t of the notch 208d is set in consideration of the return of the end faces 34 and 35 of the flat plate part 60 and the periphery thereof.

  When the cylindrical roller main body 16 is formed by bending the flat plate portion 60, the roundness is worse in the central portion in the axial direction of the roller main body 16, that is, in the holding region F that holds the object to be transported, compared to the both end portions. There was a tendency to become. In this modification, since the notch 208d is provided at a position corresponding to the holding region F, the end surfaces 61a and 61b and the periphery thereof are positively urged radially inward in the holding region F, and the roller at the end of the bending process The roundness of the main body 16 can be effectively improved.

  Next, the third cored bar 208B will be described. In FIG. 38A, the conveying roller 15 and the third cored bar 208B are shown side by side for the sake of explanation. The third core bar 208B includes a notch 208f in which a portion of the outer peripheral surface 208a corresponding to the transport roller 15 is notched.

  As shown in FIGS. 38 (b) and 38 (c), the notch 208 f has a first notch depth t <b> 1 corresponding to the center of the transport roller 15 where the first notch depth t <b> 1 corresponds to both ends of the transport roller 15. It is larger than the second notch depth t2. In addition, the first notch depth t1 gradually decreases toward both ends of the transport roller 15, and becomes the second notch depth t2. The notch depth may be changed stepwise.

  Since the first notch depth t1 of the portion corresponding to the central portion of the transport roller 15 in the third cored bar 208B is larger than the second notch depth t2 at the locations corresponding to both ends of the transport roller 15, The end faces 61a and 61b and the periphery thereof are positively urged radially inward at the location corresponding to the central portion, and the roundness of the roller body 16 at the end of the bending process can be effectively improved.

  In the above description, the configuration in which the thickness of the roller body 16 is uniform has been described as an example. However, the configuration is not limited to this, and the thickness may be changed according to the position of the roller body 16. I do not care. FIG. 39 is a view showing a cross-sectional shape orthogonal to the axis O1 of the roller body 16. As shown in FIG.

  In the cross-sectional shape shown in FIG. 39, the roller main body 16 has a thickness Th1 of the first axial facing portions 160 facing each other in the first straight line CL1 passing through the joint 80 and the axial center O1, and the first straight line CL1 in the axial center O1. Is configured to be smaller than the thickness Th2 of the second axially opposed portions 161 facing each other on the second straight line CL2 orthogonal to the horizontal axis CL2. That is, the relationship is Th1 <Th2.

  In addition, the 1st axial center opposing part 160 means the specific site | part of the roller main body 16 in the predetermined area | region which mutually opposes in the 1st straight line CL1 which passes along the joint 80 and the axial center O1. Further, the second axial center facing portion 161 refers to a specific portion of the roller body 16 in a predetermined region facing each other on the second straight line CL2 orthogonal to the first straight line CL1 in the axial center O1.

  In this cross-sectional shape, the thickness of the roller body 16 between the first axially facing part 160 and the second axially facing part 161 increases from the first axially facing part 160 toward the second axially facing part 161. It is configured to change gradually. That is, assuming that the position where the joint 80 is formed is the 0 o'clock position, the thickness of the roller body 16 continuously increases from the thickness Th1 to the thickness Th2 from the 0 o'clock position toward the 3 o'clock position or the 9 o'clock position. The thickness of the roller main body 16 continuously decreases from the thickness Th2 to the thickness Th1 as it goes from the 3 o'clock position or the 9 o'clock position to the 6 o'clock position.

  In the present embodiment, in the cross-sectional shape shown in FIG. 39, the outer diameter shape of the roller body 16 (the shape of the outer peripheral surface 16a) is a perfect circle shape centered on the axis O1. In the cross-sectional shape shown in FIG. 39, the inner diameter shape of the roller body 16 (the shape of the inner peripheral surface 16b) is an elliptical shape centered on the axis O1. More specifically, the inner diameter shape of the roller body 16 is an elliptical shape with the major axis being arranged on the first straight line CL1 and the minor axis being arranged on the second straight line CL2, with the axis O1 as the center.

  In the cross-sectional shape shown in FIG. 39, the roller main body 16 of the present embodiment has a line-symmetric shape with respect to the first straight line CL1 and a line-symmetric shape with respect to the second straight line CL2.

  The thickness difference between the thickness Th1 of the first axially opposed portion 160 and the thickness Th2 of the second axially opposed portion 161 is set within a range of 10% or more and 50% or less when the thickness Th2 is 100%. . If the thickness Th2 of the second axially opposed portion 161 is 1.00 mm, the difference between the thickness Th1 and the thickness Th2 is in the range of 0.10 mm to 0.50 mm.

  Specifically, in the example of the present embodiment, the difference between the thickness Th1 and the thickness Th2 is set to 0.15 mm, which is a 15% thickness difference. That is, the thickness Th2 is set to 1.00 mm, and the thickness Th1 is set to 0.85 mm.

  When forming the roller main body 16 as described above, for example, as shown in FIG. 40, the cross-sectional shape of the roller main body 16 is arranged on the first straight line CL1 by the pressing process (bending process), and the second straight line is formed. It is made to become the ellipse shape by which a short axis is arrange | positioned on CL2. In this case, for example, a core material having an elliptical cross-sectional view is used.

  In the cross-sectional shape shown in FIG. 40, the first axially opposed portion 160 is disposed at a position corresponding to the major axis of the elliptical shape. Further, the second axial center opposing portion 161 is disposed at a position corresponding to the elliptical minor axis. The roller body 16 has a substantially uniform thickness. That is, the thickness Th1 of the first axial center facing portion 160 and the thickness Th2 of the second axial center facing portion 161 are substantially the same.

  Next, centerless polishing is performed on the roller body 16 using the grindstone member GD of the above embodiment. In this polishing step, the portion corresponding to the first axially opposed portion 160 is determined according to the thickness difference between the thickness Th1 of the first axially opposed portion 160 and the thickness Th2 of the second axially opposed portion 161 shown in FIG. Preferentially polish and scrape off.

  In this centerless polishing process, the outer peripheral surface 16a of the roller body 16 is polished while the roller body 16 rotates in the direction opposite to the rotation direction of the grinding wheel member GD due to the frictional force generated by the rotation of the grinding wheel member GD. Will be. For this reason, almost the entire outer peripheral surface 16a of the roller body 16 is uniformly ground, and the roundness of the roller body 16 is increased and the runout is reduced as compared with that before the centerless polishing step.

  In this centerless polishing process, the protruding portion of the roller body 16 due to the rotation of the grindstone member GD (the first axially opposed portion 160 protruding outward from the virtual perfect circle shape indicated by the two-dot chain line in FIG. 40) is preferential. It will be polished. For this reason, when the roller body 16 whose outer diameter shape is elliptical is centerless polished, the outer diameter shape is processed into a perfect circle shape, but the first axially opposed portion protruding from the perfect circle shape. 160 is scraped off more than the second axially opposed portion 161. As a result, as shown in FIG. 39, in the cross-sectional shape, the thickness Th1 of the first axially opposed portion 160 can be made smaller than the thickness Th2 of the second axially opposed portion 161, and the first axially opposed portion 160 It becomes possible to gradually change the thickness gradually toward the biaxially opposed portion 161.

  Moreover, in the said embodiment, you may make it perform the process (stress adjustment process) of adjusting the stress which remains in the roller main body 16 formed by the press process (bending process). 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, for example.

(1) Roll leveler process
In the roll leveler process, a plurality of pressing rollers are used. Here, for example, as shown in FIG. 41A, a case where two pressing rollers R1 and R2 are used will be described as an example. The pressing roller R1 has an outer peripheral surface formed in a convex shape, for example. Moreover, as for press roller R2, the outer peripheral surface is formed in concave shape, for example.

  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.

  For example, 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. 41 (b), 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 region 50, for example, spiral recesses 201a and 202a are formed on the surfaces of the rolling rollers 201 and 202, and the recesses 201a and 202a deform the surface of the roller main 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, for example.

  In the rolling process, for example, by making the axial dimension of the rolling rollers 201 and 202 equal to the axial dimension of the roller body 16, a pressing force is applied to the entire 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 press 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.

  As a rotation press process, the example which moves the roller main body 16 as shown, for example in FIG.41 (c) is mentioned. In this case, for example, 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, for example.

  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 16 f of the roller body 16 to the second end 16 s. By this pressing force, the stress remaining in the roller body 16 is adjusted.

  Moreover, as a rotation press process, as shown in FIG.41 (d), the example which moves the press member R5 without moving the roller main body 16 is mentioned. In this case, for example, 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 16 f of the roller body 16 to the second end 16 s. 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, for example in the shape of a roller.

  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, another example of the method for manufacturing the transport roller 15 will be described. FIG. 42 is a flowchart showing the manufacturing process.
As shown in FIG. 42, among the processes shown above, for example, a press process, a spot welding process, a rough centerless process, a stress adjustment process, a finishing centerless process (centerless polishing process), a plating process, and a painting process. , In order. In this case, the conveyance operation between processes can be performed smoothly.

  Note that this manufacturing method is merely an example. For this reason, for example, each step may be performed in an order different from the above order, or for example, some of the above steps may not be performed. In addition, other steps different from the above steps such as a heating step, a cooling step, and a step of applying a force to the roller body 16 may be appropriately inserted in the above order.

  Further, for example, as shown in FIG. 43, in addition to the configuration of the above-described embodiment, a conveyance area CA that is brought into contact with the recording paper P in the length direction (axial direction) is defined, and is one end than the conveyance area CA. Conveying drive gear 35 and inner gear 36 are provided on the side (left side in FIG. 43), and third driving gear 37 is provided on the other end side (left side in FIG. 43) from the conveying area CA. can do.

  The conveyance drive gear 35 is a gear for rotating the conveyance roller 15, and is integrally connected to the end of the conveyance roller 15 on the drive unit 6 installation side by press-fitting. Further, the transport drive gear 35 meshes with the pinion 33, and the driving force of the transport motor 32 is transmitted to the transport roller 15 through the pinion 33 and the transport drive gear 35 so that the transport roller 15 rotates. Yes. The inner gear 39 is a gear for transmitting the driving force of the transport motor 32 to a paper discharge roller 27 as a processing device, has a smaller diameter than the transport drive gear 35, and is adjacent to the transport drive gear 35. It is arranged coaxially.

  The third drive gear 37 transmits the rotational driving force of the transport roller 15 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 15 transports the recording paper P is set.

  A discharge driving gear 43 is integrally provided at the end of the discharge roller 27 on the drive unit 6 side. An intermediate gear 41 is provided between the paper discharge drive gear 43 and the inner gear 39, and the intermediate gear 41 meshes with each of the inner gear 39 and the paper discharge drive gear 43. That is, the driving force of the transport motor 32 is transmitted to the paper discharge roller 27 via the inner gear 39, the intermediate gear 41, and the paper discharge drive gear 43, and the paper discharge roller 27 rotates, so that paper discharge is performed as a process related to printing. Processing is performed.

  Since both the conveyance drive gear 35 and the inner gear 39 are arranged on one end side with respect to the conveyance area CA of the conveyance roller 15, it is possible to suppress a decrease in conveyance accuracy and printing accuracy of the recording paper P. Further, the joint 80 on one end side of the transport roller 15 in which the transport drive gear 35 and the inner gear 39 are disposed is a bent portion 85 formed by fitting the concave and convex portions as shown in FIG. 44, for example. By adopting a configuration in which the joint 80 has the intersecting portion 85a, the joint 80 can be prevented from shifting in the direction of the central axis 16c. Therefore, deformation of the transport roller 15 (roller body 16) can be suppressed, and a decrease in the transport accuracy of the transport roller 15 due to the deformation can also be suppressed.

  Note that the rotational driving of the paper discharge roller 27 is such that the driving force of the transport motor 32 transmitted to the transport roller 15 via the transport drive gear 35 is transmitted via the inner gear 39, and the recording paper P is driven by the drive of the transport roller 15. This is also performed during the transport process. Since both the transport drive gear 35 and the inner gear 39 are arranged on one end side with respect to the transport area CA of the transport roller 15, the torque applied to the transport roller 15 (roller body 16) does not act on the transport 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 transport motor 32 transmitted to the transport roller 15 via the transport 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 15 on the opposite side to the transport drive gear 35 across the transport area CA, the operation of the other device 38 is performed in the transport area CA. However, since the third driving gear 37 is connected to a device 38 that is inactivated when the transport roller 15 transports the recording paper P, the recording paper is operated when the device 38 is operated. The transport of P is not performed, and therefore the transport accuracy and hence the print accuracy is not lowered. Furthermore, according to this configuration, the joint 80 of the transport roller 15 in the transport area CA is the central straight portion 86, and the length of the joint 80 is minimized, and thus the joint 80 is caused by the joint 80. A decrease in conveyance accuracy and printing accuracy can be further suppressed.

  As described above, since both the transport driving gear 35 and the inner gear 39 are disposed on one end side with respect to the transport area CA of the transport roller 15, it is possible to suppress a decrease in transport accuracy and print accuracy of the recording paper P. become. Further, the joint 80 on one end side of the transport roller 15 in which the transport drive gear 35 and the inner gear 39 are disposed is a bent portion 85 formed by fitting the uneven portion, and the joint 80 intersects. Since the portion 85a is provided, the joint 80 can be prevented from shifting in the direction of the central axis 16c. Therefore, deformation of the transport roller 15 (roller body 16) can be suppressed, and a decrease in the transport accuracy of the transport roller 15 due to the deformation can also be suppressed.

  Further, by connecting a device 38 that is inactivated when the transport roller 15 transports the recording paper P to the third drive gear 37 provided on the other end side of the transport roller 15, the transport accuracy is reduced. It is possible to efficiently use the driving force of the transport motor 32 without inviting it, which can contribute to the downsizing and cost reduction of the apparatus. Moreover, since the joint 80 on the other end side of the transport roller 15 on which the third drive gear 37 is disposed also has the intersection 85b, the joint 80 can be prevented from shifting in the direction of the central axis 16c. . Therefore, deformation of the transport roller 15 (roller body 16) can be suppressed, and a decrease in the transport accuracy of the transport roller 15 due to the deformation can also be suppressed.

  CONT ... Control part C ... Coil M ... Metal plate 1 ... Inkjet printer 15 ... Conveying roller 16 ... Roller body 50 ... High friction layer 60 ... Plate part

Claims (14)

A drive unit;
Conveying rollers that are opposed to each other and that include a cylindrical shaft having end faces that form joints, and that are driven by the drive unit;
A high friction layer provided on an outer periphery of the cylindrical shaft in contact with the conveyance medium in the conveyance roller;
A printing unit that performs a printing process on the transport medium transported by the transport roller,
The seam is the outer peripheral surface of the cylindrical shaft is in contact of the end face, so that the state of the inner peripheral surface side of the cylindrical shaft is separated out of the end face, the printing device end surface is formed. A drive unit;
Conveying rollers that are opposed to each other and that include a cylindrical shaft having end faces that form joints, and that are driven by the drive unit;
A high friction layer provided on an outer periphery of the cylindrical shaft in contact with the conveyance medium in the conveyance roller;
A printing unit that performs a printing process on the transport medium transported by the transport roller,
The joint is formed so as to straddle the high friction layer,
A printing apparatus in which an opening penetrating the inside and outside of the cylindrical shaft is formed at a position outside the high friction layer in the joint. A drive unit;
Conveying rollers that are opposed to each other and that include a cylindrical shaft having end faces that form joints, and that are driven by the drive unit;
A high friction layer provided on an outer periphery of the cylindrical shaft in contact with the conveyance medium in the conveyance roller;
A printing unit that performs a printing process on the transport medium transported by the transport roller,
The printing apparatus, wherein the cylindrical shaft is formed such that a thickness at the joint is smaller than a thickness at other portions. The printing apparatus according to any one of claims 1 to 3 , wherein the joint includes a linear portion formed in parallel to a central axis direction of the transport roller. The printing apparatus according to any one of claims 1 to 4 , wherein the joint has an intersecting portion formed in a direction intersecting a central axis direction of the transport roller. The printing apparatus according to any one of claims 1 to 4 , wherein the joint has an inclined portion formed in a direction inclined with respect to a central axis direction of the transport roller. The printing apparatus according to any one of claims 1 to 6 , wherein the joint has a curved portion formed by being curved. The high friction layer includes at least one of inorganic particles and organic particles,
The printing apparatus according to any one of claims 1 to 7 , wherein an average particle diameter of the particles is larger than a distance between the pair of end portions in the joint. The printing apparatus according to any one of claims 1 to 8 , wherein the transport roller includes a connected portion connected to the drive unit that rotates the transport roller. The printing apparatus according to claim 9 , wherein the connected portion is provided at an end portion of the transport roller. Wherein the connecting portion, the printing apparatus according to claim 9 or claim 1 0 having a circumferential portion is cut out cutout portion formed of the conveying roller. The transport roller has a joint that joins between the pair of ends.
The notch to a printing apparatus of claim 1 1 which is provided at a portion deviated from the joint in the circumferential direction of the transport roller. The transport roller has a connection portion where a pair of end portions of the metal plate are in contact with each other;
Formed on the outer peripheral surface, the printing apparatus according to any one of claims 1 2 to claim 1 having a second cutout portion provided in the non-position of the connecting portion. The transport roller has a transport area for transporting the transport medium,
A first drive member that is provided on one end side of the transport roller relative to the transport region, and transmits a rotational driving force to the transport roller;
A second driving member that transmits the transmitted rotational driving force to a processing device that performs processing related to printing;
Printing apparatus according to any one of claims 1 to 3 claim 1, further comprising a.

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