JP2016172640A - Transport device and printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transport device which inhibits deterioration of transport accuracy even when manufacturing errors occur in rollers to be connected, and to provide a printer.SOLUTION: A transport device transports a medium by a transport roller including: rollers 71 (71F, 71S) arranged along a rotation axis direction; and a connection part 72 which connects end parts of the two rollers 71 arranged in the rotation axis direction. The connection part 72 includes: a first bearing 73 which rotatably supports an end part of the first roller 71F; a second bearing 74 which rotatably supports an end part of the second roller 71S; a fixing member 75 to which the bearings 73, 74 are fixed; and a fastening part 76 which is disposed between the first bearing 73 and the second bearing 74 in the rotation axis direction and fastens the end part of the first roller 71F to the end part of the second roller 71S so that a rotational force may be transmitted therebetween.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a transport apparatus that transports a medium and a printing apparatus including the transport apparatus.

  Some printers, which are examples of printing apparatuses, include a conveyance device that conveys a print medium using conveyance rollers. In such a transport apparatus, when the width of the medium to be transported increases, it is necessary to increase the length of the transport roller in the width direction accordingly. However, when the length of the transport roller is increased as described above, there is a problem that a manufacturing error increases and the transport accuracy decreases.

  Therefore, in order to cope with such a problem, conventionally, there is a conveyance device that configures a conveyance roller by connecting a plurality of driving rollers in the width direction using an Oldham type coupling (for example, Patent Document 1).

JP 2000-44084 A

  By the way, the Oldham type coupling is characterized in that a protrusion is provided on one of the two rotating shafts to be connected and a groove is provided on the other, and the eccentricity is allowed by sliding one protrusion along the groove on the other. There is. Thus, if the eccentricity can be allowed by the coupling, there is an advantage that a manufacturing error of each driving roller can be allowed. However, the Oldham type coupling has a problem that due to its structure, the projections and grooves wear with use, resulting in increased backlash and reduced transport accuracy.

  Such a problem is not limited to a conveyance device used in a printer, but is generally common in a conveyance device and a printing device including a conveyance roller for conveying a medium.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transport device and a printing device that can suppress a decrease in transport accuracy even when there are manufacturing errors in a plurality of rollers to be connected. There is to do.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A transport device that solves the above-described problem transports a medium by a transport roller that includes a plurality of rollers arranged along the rotation axis direction and a connecting portion that connects ends of the two rollers arranged in the rotation axis direction. The transporting device, wherein the connecting portion supports the end portion of the first roller in a rotatable state when the two rollers arranged in the rotation axis direction are respectively a first roller and a second roller. A first bearing that supports the end of the second roller in a rotatable state, a fixing member to which the first bearing and the second bearing are fixed, and the first bearing in the rotational axis direction. A fastening portion that is disposed between one bearing and the second bearing and fastens the end portion of the first roller and the end portion of the second roller;

  According to this structure, although the edge part of the some roller which comprises a conveyance roller is rotatably supported by a bearing, when these bearings are fixed to a fixing member, a roller is pinched | interposed into two bearings. The displacement of the part is restricted. In this state, when the fastening part fastens the ends of the two rollers, even if there is a manufacturing error of the roller in the fastening part, the position of the rotation shaft of the part sandwiched between the two bearings does not change. A decrease in the conveyance accuracy as a whole is suppressed. Therefore, even when there are manufacturing errors in the plurality of rollers to be connected, it is possible to suppress a decrease in conveyance accuracy.

  In the transport apparatus, the roller has a shaft portion positioned at an end portion in the rotation axis direction, and the fastening portion includes rotation shaft centers of the first bearing and the second bearing and a rotation shaft of the shaft portion. The shaft portion of the first roller and the shaft portion of the second roller can be fastened in a state in which a center deviation is allowed.

  According to this configuration, even when there is a manufacturing error in the shaft portion of the roller to be connected and the rotation shaft center of the shaft portion is eccentric or deviated with respect to the rotation shaft center of the portion supported by the bearing. Since the fastening portion can fasten the shaft portions of the rollers in a state where such deviation is allowed, it is possible to connect two rollers having a manufacturing error in the connecting portion.

  In the transport apparatus, the roller includes a shaft portion positioned at an end portion in the rotation axis direction, and the shaft portion includes a large-diameter portion that can contact the fastening portion when fastened by the fastening portion; A small-diameter portion having an outer diameter smaller than that of the diameter portion.

  According to this structure, when a fastening part fastens the edge parts of two rollers, the large diameter part provided in these edge parts contacts a fastening part, but an outer diameter is smaller than the large diameter part The small diameter portion does not contact the fastening portion. In other words, since the area where the fastening portion contacts the shaft portion is small in the rotation axis direction, the inclination of the shaft portion is allowed in the range of the gap generated between the small diameter portion and the fastening portion. Therefore, even when the shaft portions of the rollers to be connected are deviated, the fastening portion can fasten the shaft portions of the rollers in a state where such declination is allowed, so there are a plurality of manufacturing errors in the connection portion. Roller can be connected.

  In the transport apparatus, the fastening portion includes a shaft hole forming member having a cylindrical shape and an inner peripheral surface forming a shaft hole, and the shaft hole forming member communicates with the shaft hole and is in the rotation axis direction. A notch formed in the cylindrical portion so as to extend to the first screw hole extending in a direction crossing the rotational axis direction, and being opposed to the cylindrical portion so as to sandwich the shaft hole. A diameter of the shaft hole can be reduced by tightening a bolt that is screwed into the second screw hole. The second screw hole is provided at a position closer to the notch than the first screw hole. The two screws screwed into the first screw hole can protrude into the shaft hole.

  According to this configuration, the shaft hole forming member constituting the fastening portion has the notch communicating with the shaft hole formed by the inner peripheral surface thereof, so that the second screw hole provided at a position close to the notch By tightening the inserted bolt, the width of the notch can be reduced and the diameter of the shaft hole can be reduced. Therefore, by reducing the diameter of the shaft hole with the end of the first roller and the end of the second roller inserted from both ends of the shaft hole, the ends of the two rollers inserted into the shaft hole Can be concluded. Further, the end of the roller inserted into the shaft hole is not moved relative to the shaft hole forming member by projecting the screw screwed into the first screw hole paired so as to sandwich the shaft hole into the shaft hole. Can be fixed. Thereby, a rotational force can be reliably transmitted between a 1st roller and a 2nd roller via a fastening part.

A printing apparatus that solves the above problem includes the transport device and a printing unit that performs printing on the medium transported by the transport device.
According to this configuration, the printing unit can accurately print the medium conveyed by the conveyance roller by suppressing the decrease in the conveyance accuracy by the action of the conveyance device.

FIG. 3 is a cross-sectional view schematically illustrating an embodiment of the printing apparatus and the conveyance apparatus according to the first embodiment. The front view which shows the structure of the conveying apparatus of 1st Embodiment. The expanded sectional view of the part enclosed with a dashed-dotted line in FIG. The perspective view which looked at the fastening part of a 1st embodiment from the 1st direction. The perspective view which looked at the fastening part of a 1st embodiment from the 2nd direction. The perspective view which looked at the fastening part of a 1st embodiment from the 3rd direction. Sectional drawing which cuts and shows the structure of the fastening part of 1st Embodiment by the cut surface shown by a 7-7 line arrow in FIG. Sectional drawing for demonstrating the effect | action of the connection part of 1st Embodiment. The schematic diagram explaining the force which acts on the roller of a comparative example. The schematic diagram explaining the force which acts on the roller of 1st Embodiment. Sectional drawing of the conveying apparatus of 2nd Embodiment. Sectional drawing for demonstrating the effect | action of the conveying apparatus of 2nd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of a printing apparatus will be described with reference to the drawings. The printing apparatus is, for example, a large format printer that performs printing (recording) on a long medium.

  As shown in FIG. 1, the printing apparatus 11 conveys the medium M in a direction indicated by an arrow in FIG. 1, a feeding unit 20 that feeds the medium M wound in a roll shape, a support unit 30 that supports the medium M, and the like. A conveying device 40 that performs printing on the medium M, and a winding unit 60 that winds up the printed medium M.

  In the following description, one direction along the width direction orthogonal to the longitudinal direction of the medium M (the direction orthogonal to the paper surface in FIG. 1) is defined as the scanning direction X, and the medium M is conveyed at a position where the printing unit 50 performs printing. Let the direction be the transport direction Y. In the present embodiment, the scanning direction X and the transport direction Y intersect with each other (preferably orthogonal), and both intersect with the gravity direction Z (preferably orthogonal).

  As illustrated in FIG. 1, the feeding unit 20 includes a holding unit 22 that holds a roll body 21 in which the medium M is wound in a roll shape. The holding unit 22 can hold a plurality of types of roll bodies 21 having different lengths and winding numbers in the scanning direction X. Then, the feeding unit 20 feeds the medium M from the roll body 21 by rotating the roll body 21 in one direction (counterclockwise in FIG. 1).

  The support unit 30 includes a first support unit 31 that forms a transport path for the medium M, a second support unit 32, and a third support unit 33. The first support unit 31 guides the medium M fed from the feeding unit 20 toward the second support unit 32. The second support unit 32 is provided at a position facing the printing unit 50 and supports the medium M on which printing is performed. The third support unit 33 guides the medium M printed by the printing unit 50 toward the winding unit 60.

  The printing unit 50 includes a guide shaft 51 extending in the scanning direction X, a carriage 52 supported by the guide shaft 51, and a print head 53 that ejects ink onto the medium M. The carriage 52 reciprocates in the scanning direction X along the guide shaft 51 by driving a carriage motor (not shown). The print head 53 is held vertically below the carriage 52 so as to face the medium M supported by the second support portion 32. The printing unit 50 performs a printing operation for forming characters and images on the medium M by ejecting ink from the print head 53 when the carriage 52 moves in the scanning direction X.

  The winding unit 60 includes a holding unit 62 that holds a roll body 61 in which the medium M is wound in a roll shape. Then, the winding unit 60 winds the printed medium M by rotating the roll body 61 in one direction (counterclockwise in FIG. 1).

Next, the configuration of the transport device 40 will be described in detail.
The transport device 40 includes a transport roller pair 41 provided between the first support portion 31 and the second support portion 32 in the transport direction Y, and a space between the second support portion 32 and the third support portion 33. A pair of paper discharge rollers 42, and a transport motor 43. In the present embodiment, the rotation axis directions of the transport roller pair 41 and the discharge roller pair 42 are directions along the scanning direction X.

  The transport roller pair 41 is configured by a pair of a transport roller 46 disposed on the support base 45 and a driven roller 48 supported by the support mechanism 47, and a medium is formed by the transport roller 46 and the driven roller 48. Hold M. Further, the support mechanism 47 includes a biasing member (not shown) that biases the driven roller 48 so as to press the driven roller 48 toward the transport roller 46. Then, the transport roller pair 41 transports the sandwiched medium M toward the second support portion 32 as the transport roller 46 rotates counterclockwise in FIG. 1 based on the driving force of the transport motor 43.

  As illustrated in FIG. 2, the transport device 40 includes a plurality of rollers 71 (71F, 71S) arranged along the rotation axis direction and at least one connection that connects ends of the two rollers 71 arranged in the rotation axis direction. Unit 72. And the conveyance roller 46 is comprised by the some roller 71 connected by the connection part 72. FIG.

  The support mechanism 47 is provided at a position corresponding to the roller 71 along the rotation axis direction, and one support mechanism 47 supports the plurality of driven rollers 48 in a rotatable manner. The driven roller 48 is disposed so as to avoid the connecting portion 72 and presses the medium M toward the roller 71.

  Assuming that the two rollers 71 arranged in the rotation axis direction in the transport roller 46 are the first roller 71F and the second roller 71S, respectively, in the present embodiment, the three first rollers 71F and the two rollers arranged alternately in the rotation axis direction. The transport roller 46 is configured by the second roller 71S and the four connecting portions 72 disposed between the rollers 71F and 71S. In addition, the number of the rollers 71 and the connection part 72 which comprise the conveyance roller 46 can be changed arbitrarily. In addition, among the plurality of rollers 71 constituting the transport roller 46, the end portion where the connecting portions 72 of the rollers 71 located at both ends in the rotation axis direction are not provided is the side wall portion 44 integrated with the support base 45. Is rotatably supported.

  The connecting portion 72 includes a first bearing 73 that supports the end portion of the first roller 71F in a rotatable state, a second bearing 74 that supports the end portion of the second roller 71S in a rotatable state, and a first bearing. 73, a fixing member 75 to which the second bearing 74 is fixed, a fastening portion 76, and a cover member 77 that covers the fastening portion 76. The first bearing 73 and the second bearing 74 are fixed to the fixing member 75 in a state where movement in the rotation axis direction and the direction intersecting the rotation axis direction is restricted. The fastening portion 76 is disposed between the first bearing 73 and the second bearing 74 in the rotation axis direction, and fastens the end portion of the first roller 71F and the end portion of the second roller 71S so as to transmit the rotational force. The cover member 77 covers the fastening portion 76 having an outer diameter smaller than that of the roller 71 so that the medium M does not bend downward in the connecting portion 72.

  As shown in FIG. 3, the roller 71 has a cylindrical contact portion 78 that can come into contact with the medium M when transporting the medium M, and has an outer diameter smaller than that of the contact portion 78 and is positioned at both ends in the rotation axis direction. And a pair of shaft portions 79. The first bearing 73 and the second bearing 74 are respectively arranged such that the rotation axis centers C1 and C2 of the contact portions 78 of the first roller 71F and the second roller 71S coincide with the rotation axis centers. Attached to. When the bearings 73 and 74 are fixed to the fixing member 75, the first roller 71F and the second roller 71S are in a state in which the displacement of the portion (contact portion 78) sandwiched between the two bearings 73 and 74 is restricted. become.

  However, in practice, there are internal gaps in the bearings 73 and 74. For this reason, the roller 71 engaged with the inner peripheral portions of the bearings 73 and 74 is slightly smaller in the axial direction and the radial direction of the bearings 73 and 74 than the fixing member 75 engaged with the outer peripheral portions of the bearings 73 and 74. There is a relative displacement. In other words, the bearings 73 and 74 do not support the roller 71 in a fixed manner. Therefore, when a force or a moment acts on the shaft portion 79 of the roller 71, the influence reaches the contact portion 78 of the roller 71. Become.

  The shaft portion 79 is engaged with the large-diameter portion 79a that can come into contact with the fastening portion 76 when fastened by the fastening portion 76, the small-diameter portion 79b whose outer diameter is smaller than the large-diameter portion 79a, and the first bearing 73 or the second bearing 74. Engaging portion 79c. In the roller 71 of the present embodiment, the large diameter portion 79a is provided at the tip of the shaft portion 79, and the small diameter portion 79b is provided between the large diameter portion 79a and the engaging portion 79c in the rotation axis direction.

  As shown in FIGS. 4, 5, and 6, the fastening portion 76 includes a shaft hole forming member 81 having a cylindrical shape and an inner peripheral surface forming a shaft hole 81 a. The shaft hole forming member 81 communicates with the shaft hole 81a and is opposed to the first notch 81b formed on the cylindrical portion so as to extend in the rotation axis direction and on the inner peripheral surface of the cylindrical portion. And a second notch 81d extending in the circumferential direction from the first notch 81b to the groove 81c.

  In the cylindrical part of the shaft hole forming member 81, two parts defined by the first notch 81b, the second notch 81d, and the groove part 81c are defined as a first fixing part 82 and a second fixing part 83, and The other half-cylindrical part (the part from the first notch 81 b to the groove part 81 c) is defined as a main body part 84. In this case, in the rotation axis direction, the first fixing portion 82 and the second fixing portion 83 are arranged so as to be aligned in the rotation axis direction, and the first fixing portion 82 is provided at a position corresponding to the shaft portion 79 of the first roller 71F. On the other hand, the second fixing portion 83 is provided at a position corresponding to the shaft portion 79 of the second roller 71S.

  As shown in FIGS. 4 to 7, the shaft hole forming members 81 are arranged so as to face the cylindrical portion so as to sandwich the shaft hole 81 a, and extend in a direction intersecting (orthogonal) with the rotation axis direction. A first screw hole 85, two pairs of second screw holes 86 provided in positions closer to the first notch 81 b than the first screw hole 85, with the axial direction parallel to the first screw hole 85. Have The first screw hole 85 (85A, 85B) and the second screw hole 86 (86a, 86b) are preferably provided at a position corresponding to the large diameter part 79a in the shaft part 79 of the roller 71 in the rotation axis direction.

  A bolt 88 having a head is inserted into the second screw hole 86. Of the paired second screw holes 86 a and 86 b, one (right in FIG. 7) screw hole 86 a is formed in a shape that can accommodate the head of the bolt 88. When the bolt 88 is inserted and tightened from one screw hole 86a to the other screw hole 86b so as to straddle the first notch 81b, a gap generated by the first notch 81b is reduced. As described above, the fixing portions 82 and 83 are bent and displaced about the groove portion 81c.

  That is, since the shaft hole forming member 81 has the first notch 81b and the groove 81c in the cylindrical portion, the diameter of the shaft hole 81a is reduced by tightening the bolt 88 screwed into the second screw hole 86. It has a possible configuration. The shaft hole forming member 81 is inserted in the state where the end portion (shaft portion 79) of the first roller 71F and the end portion (shaft portion 79) of the second roller 71S are inserted from both ends of the shaft hole 81a in the rotation axis direction. As the shaft hole 81a formed by is reduced, the shaft portion 79 of the roller 71 is fastened and fixed.

  The screw hole 86a which is one of the paired second screw holes 86 is provided in the main body portion 84 so as to be aligned in the rotation axis direction. Moreover, the screw hole 86b which is the other of the paired second screw holes 86 is provided in the first fixing portion 82 and the second fixing portion 83 so as to be aligned in the rotation axis direction. The two bolts 88 arranged in the rotation axis direction fix the shaft portion 79 of the first roller 71F and the shaft portion 79 of the second roller 71S to the shaft hole forming member 81, respectively.

  Two screws (potato screws) 87 having no head are inserted through the first screw holes 85A and 85B, respectively. Of the screws 87, the screw 87A is inserted through the screw hole 85A, and the screw 87B is inserted through the screw hole 85B.

  When the two screws 87 are respectively screwed into the first screw holes 85A and 85B and tightened, both end portions project into the shaft hole 81a and abut against the large-diameter portion 79a of the roller 71. The shaft portion 79 is sandwiched. Thereby, the relative movement in the circumferential direction of the shaft portion 79 of the roller 71 fastened and fixed by the reduction of the shaft hole 81a with respect to the shaft hole forming member 81 is more firmly regulated.

  The screw hole 85A, which is one of the paired first screw holes 85, is provided in the main body portion 84 so as to be aligned in the rotation axis direction near the center in the circumferential direction. Further, the screw hole 85B which is the other of the paired first screw holes 85 is provided in the vicinity of the center in the circumferential direction in the first fixing portion 82 and the second fixing portion 83 arranged in the rotation axis direction. The two screws 87 arranged in the rotation axis direction fix the shaft portion 79 of the first roller 71F and the shaft portion 79 of the second roller 71S to the shaft hole forming member 81, respectively.

  As shown in FIG. 7, in the cross section obtained by cutting the shaft hole forming member 81 along a plane orthogonal to the rotation axis direction, the first notch 81b and the groove portion 81c of the shaft hole forming member 81 face each other, and It is preferable that the imaginary line L1 connecting the two intersects with the central axis C3 of the cylindrical portion of the shaft hole forming member 81. Moreover, it is preferable to arrange | position the 1st screw hole 85 (85A, 85B) which makes a pair so that those axis lines L2 which correspond may be orthogonal to the virtual line L1 in the central axis C3. In FIG. 7, the shaft portion 79 is illustrated to be smaller than the actual size in order to clearly show the positional relationship between the constituent members.

Next, a method for connecting the first roller 71F and the second roller 71S will be described.
First, in a state where the shaft portions 79 of the first roller 71F and the second roller 71S are inserted into positions corresponding to the first fixing portion 82 and the second fixing portion 83 of the shaft hole forming member 81, respectively, A bolt 88 is inserted into the second screw hole 86 and lightly tightened. Then, the width of the first notch 81b is reduced and the shaft hole 81a is reduced, so that the shaft portion 79 of the first roller 71F and the second roller 71S is pushed toward the groove portion 81c.

  Next, the position of the fixing member 75 that supports the bearings 73 and 74 is finely adjusted, and the rotation axis center C1 of the contact portion 78 of the first roller 71F and the rotation axis center C2 of the contact portion 78 of the second roller 71S are adjusted. At the same time, the rotation axis centers C1 and C2 are made to coincide with the rotation axis centers of the bearings 73 and 74.

  Subsequently, the screw 87 is inserted into the first screw hole 85 and lightly tightened. At this time, it is preferable that the screw portions 85A and the other screw holes 85B are alternately tightened while maintaining a balance so as to sandwich the shaft portion 79 evenly. For example, after the screw 87B is inserted into the screw hole 85B formed in the first fixing part 82 and the second fixing part 83 and rotated by a predetermined amount, the screw 87A is inserted into the screw hole 85A formed in the main body part 84. Insert and rotate to the same extent. As a result, the tip of the screw 87 protruding from the screw hole 85A into the shaft hole 81a and the tip of the screw 87 protruding from the screw hole 85B into the shaft hole 81a abut against the shaft portion 79, and the shaft portion 79 against the shaft hole forming member 81 Regulate relative rotation.

  Then, after sequentially positioning the rollers 71F and 71S with respect to the shaft hole forming member 81 with the bolts 88 and the screws 87B and 87A in this way, the order of the positioning (for example, the order of the bolts 88, the screws 87B, and the screws 87A). The bolts 88 and the screw 87 are firmly tightened to fix the rollers 71F and 71S and the shaft hole forming member 81. As a result, the end of the first roller 71F and the end of the second roller 71S are fastened by the fastening portion 76.

Next, the operation of the printing apparatus 11 and the transport apparatus 40 configured as described above will be described.
The transport device 40 includes a plurality of rollers 71 arranged along the rotation axis direction, and a connection portion 72 that connects the ends of the two rollers 71 arranged in the rotation axis direction. The medium M is transported by the transport roller 46 formed by the roller 71. That is, the transport roller 46 allows the plurality of rollers 71 to be transported without increasing the size of a single member even when the width of the medium M to be transported (the length in the scanning direction X that is the rotation axis direction) is increased. Since the connection can be increased in size (lengthened), an increase in manufacturing error due to the increase in size is suppressed.

  However, when a plurality of rollers 71 are connected, each of the rollers 71 also includes a manufacturing error. Therefore, when the rollers 71 are connected in the rotation axis direction, the manufacturing errors of the individual rollers 71 are stacked, and the transport roller 46 is stacked. There is a possibility that the conveyance accuracy of the medium M is lowered due to the center of the rotation axis being curved, and the printing accuracy is thereby lowered.

  In that respect, in the transport roller 46 of the present embodiment, the portion of the engaging portion 79c close to the contact portion 78 in the shaft portion 79 in a state where the rotation shaft centers C1 and C2 of the contact portion 78 of each roller 71 coincide with each other. Are fixed by the bearings 73 and 74 and the fixing member 75 so that they cannot be moved, so that manufacturing errors of the individual rollers 71 are difficult to stack as errors of the entire transport roller 46.

  In each roller 71, there may be a manufacturing error in which the center of the rotation axis is decentered or deviated by the contact portion 78 and the shaft portion 79. The fastening portion 76 can fasten the roller 71.

  For example, as shown in FIG. 8, in the first roller 71 </ b> F, even if the rotation axis center Ax (Ax1) of the shaft portion 79 is deviated with respect to the rotation axis center C1 of the contact portion 78, the shaft hole forming member 81. In the step of tightening with the bolt 88, the first fixing portion 82 is deflected and displaced along the deviated shaft portion 79 to fix the large diameter portion 79a. In the second roller 71S, even if the rotation axis center Ax (Ax2) of the shaft portion 79 is eccentric with respect to the rotation axis center C2 of the contact portion 78, the shaft hole forming member 81 is tightened with the bolt 88 in the step of tightening. The second fixing portion 83 is deflected and displaced along the shaft portion 79 to fix the large-diameter portion 79a.

  That is, since the shaft hole forming member 81 has the first notch 81b and the groove portion 81c extending in the rotation axis direction in the cylindrical portion thereof, the shaft portion can be adjusted by adjusting the diameter of the shaft hole 81a with the tightening force of the bolt 88. The position 79 is fixed while allowing the positional deviation. Further, since the shaft hole forming member 81 has a second notch 81d extending in the circumferential direction in the cylindrical portion thereof, the fixing portions 82 and 83 defined by the second notch 81d are separately bent and displaced. The shift of the shaft portion 79 of the first roller 71F and the shaft portion 79 of the second roller 71S arranged in the rotation axis direction is individually allowed.

  When the end portions of the rollers 71F and 71S are fastened in this way, the rotation axis center Ax of each shaft portion 79 is shifted from the rotation axis centers C1 and C2 of the contact portion 78. Since the centers C1 and C2 are adjusted to coincide with the rotation axis centers of the bearings 73 and 74 and then fixed to the fixing member 75, the deviation of the shaft portion 79 is not easily reflected in the conveyance of the medium M.

  Thus, the fastening portion 76 allows the shaft portion 79 of the first roller 71F and the second roller in a state in which a deviation between the rotation shaft centers of the first bearing 73 and the second bearing 74 and the rotation shaft center Ax of the shaft portion 79 is allowed. The shaft portion 79 of 71S can be fastened. Therefore, the bearings 73 and 74 are fixed to the fixing member 75 in a state where the positions of the rotation shaft centers C1 and C2 of the contact portions 78 of the rollers 71F and 71S are matched with each other, and then the two shaft portions 79 including manufacturing errors are included. The fastening portion 76 can fasten. In this way, even if the number of rollers 71 constituting the transport roller 46 is increased, the transport accuracy of the transport roller 46 as a whole is not easily lowered, and the manufacturing accuracy of the connecting roller 71 is not so high. The conveyance accuracy of the entire conveyance roller 46 can be ensured.

  In the present embodiment, the manufacturing error of the shaft portion 79 can be easily tolerated by providing the shaft portion 79 with the small diameter portion 79b to reduce the contact area of the shaft portion 79 with the shaft hole forming member 81. . However, when the rotation is transmitted from one roller 71 to the other roller 71 by reducing the contact area of the shaft portion 79 with respect to the shaft hole forming member 81, the shaft portion 79 of the other roller 71 is connected to the shaft hole forming member. There is a risk of slipping in the circumferential direction with respect to 81.

  In that respect, if the large-diameter portion 79a in contact with the fastening portion 76 in the shaft portion 79 is fixed with two screws 87, relative movement in the circumferential direction of the roller 71 and the shaft hole forming member 81 is suppressed, and one roller The rotational force can be reliably transmitted from 71 to the other roller 71. In addition, in the fastening part 76, even if it makes the two screws 87 contact the small diameter part 79b, the relative rotation with respect to the shaft hole formation member 81 of the roller 71 can be suppressed.

  Further, as shown in FIG. 7, since the second screw hole 86 through which the bolt 88 is inserted is located near the first notch 81b, when the bolt 88 is tightened to reduce the diameter of the shaft hole 81a, the shaft hole 81a The shaft portion 79 inserted through is placed in a state of being moved toward the groove portion 81c. That is, the rotation axis center Ax of the shaft portion 79 is brought closer to the position away from the first notch 81b than the center axis C3 of the shaft hole forming member 81.

  Therefore, when the first screw hole 85 is arranged so that the axis L2 of the first screw hole 85 is orthogonal to the imaginary line L1 in the central axis C3, the tip of the screw 87 inserted through the first screw hole 85 has a shaft portion. It contacts the outer peripheral surface which shifted | deviated from the rotational axis center Ax of 79 to the 1st notch 81b side. As a result, the screw 87 fixes the shaft portion 79 in such a manner that the shaft portion 79 is further pressed toward the groove portion 81c.

  Accordingly, if the positions of the first notches 81b in the circumferential direction are aligned in the plurality of connecting portions 72 arranged along the rotation axis direction, the plurality of shaft portions 79 can be fixed in the same direction. it can. Then, by aligning the positions of the rotation axis centers Ax (Ax1, Ax2) of the adjacent shaft parts 79 in this way, the positions of the rotation axis centers C1, C2 of the contact part 78 can be combined.

  Next, the moment generated in the shaft portion 79 of the rollers 71 and 71A will be described while comparing the roller 71A of the comparative example shown in FIG. 9 and the roller 71 of the present embodiment shown in FIG. 9 and 10, the inclination of the shaft portion 79 of the rollers 71 and 71A is remarkably illustrated for easy understanding of the explanation. That is, in reality, in the axial direction of the rollers 71 and 71A, the rotation axis center of the engaging portion 79c close to the contact portion 78 and the rotation axis center C1 of the contact portion 78 are substantially coincident.

  As shown in FIG. 9, the shaft portion 79 of the roller 71A of the comparative example includes only a large diameter portion 79a and an engaging portion 79c. Therefore, the contact area between the shaft portion 79 of the roller 71A of the comparative example shown in FIG. 9 and the shaft hole forming member 81 is between the shaft portion 79 of the roller 71 of this embodiment shown in FIG. 10 and the shaft hole forming member 81. It becomes larger than the contact area.

  9 and 10, when the rotation axis center Ax1 of the shaft portion 79 of the rollers 71 and 71A is deviated (inclined) with respect to the rotation axis center C1 of the contact portion 78, When the shaft portion 79 of the rollers 71 and 71A is fastened, the shaft portion 79 is deformed so that the rotation axis center Ax1 of the shaft portion 79 of the rollers 71 and 71A approaches the rotation axis center C1 of the contact portion 78.

  That is, the shaft portion 79 is inserted into the shaft hole 81a of the shaft hole forming member 81, and the diameter of the shaft hole 81a is reduced, so that the position P1 of the tip of the shaft portion 79 is more than the position P1. A load toward the rotation axis center Ax1 acts at the end position P2. That is, with reference to the position P2 of the shaft portion 79, a moment represented by the product of the distance in the axial direction (arm length) from the position P2 to the position P1 and the load F acting on the position P1 is Acts on part 79. In this case, the position P1 is a power point and the position P2 is an action point.

  In addition, this moment acts on the axial part 79 of the said rollers 71 and 71A by connecting the axial parts 79 of the rollers 71 and 71A. Since there is an internal gap in the bearing 73 that engages with the shaft portion 79 (engaging portion 79c) of the rollers 71 and 71A, when the moment increases, the contact portion 78 of the rollers 71 and 71A may be curved. is there.

  Here, as shown in FIGS. 9 and 10, when comparing the comparative example in which the small diameter portion 79b is not provided in the shaft portion 79 and the present embodiment in which the small diameter portion 79b is provided in the shaft portion 79, compared to the comparative example, In the present embodiment, the distance Lf is shorter. For this reason, by providing the small diameter part 79b, the moment which generate | occur | produces in the axial part 79 of the said roller 71 becomes smaller by connecting the axial part 79 of the roller 71 of this embodiment than the comparative example. Thus, according to the present embodiment, by connecting the shaft portion 79 of the roller 71, the possibility that the roller 71 is curved is reduced.

According to the first embodiment, the following effects can be obtained.
(1) The ends of the plurality of rollers 71 constituting the transport roller 46 are rotatably supported by bearings 73 and 74, and the rollers 71 are fixed by fixing the bearings 73 and 74 to the fixing member 75. In FIG. 5, the displacement of the portion (contact portion 78) sandwiched between the two bearings 73 and 74 is regulated. In this state, when the fastening portion 76 fastens the ends of the two rollers 71F and 71S, even if there is a manufacturing error of the roller 71 in the shaft portion 79 that is the fastening portion, it is sandwiched between the two bearings 73 and 74. Since the position of the rotation shaft of the part does not change, a decrease in the conveyance accuracy as the entire conveyance roller 46 is suppressed. Therefore, even when there are manufacturing errors in the plurality of rollers 71 to be connected, it is possible to suppress a decrease in conveyance accuracy. And by suppressing the fall of a conveyance precision by the effect | action of such a conveying apparatus 40, the printing part 50 can print with high precision with respect to the medium M which the conveyance roller 46 conveys.

  (2) There is a manufacturing error in the shaft portion 79 of the roller 71 to be connected, and the rotation shaft center Ax of the shaft portion 79 is eccentric with respect to the rotation shaft centers C1 and C2 of the contact portion 78 supported by the bearings 73 and 74. Alternatively, even when the angle is deviated, the fastening portion 76 can fasten the shaft portions 79 of the rollers 71 in a state where such deviation is allowed. Therefore, it is possible to connect two rollers 71 having manufacturing errors in the connecting portion 72.

  (3) When the fastening portion 76 fastens the ends of the two rollers 71F and 71S, the large-diameter portion 79a provided at these ends (shaft portion 79) contacts the fastening portion 76. The small diameter portion 79b having an outer diameter smaller than the diameter portion 79a does not contact the fastening portion 76. In other words, since the area where the fastening portion 76 contacts the shaft portion 79 is small in the rotation axis direction, the inclination of the shaft portion 79 is allowed in the range of the gap generated between the small diameter portion 79b and the fastening portion 76. Therefore, even when the shaft portion 79 of the roller 71 to be connected is deviated with respect to the contact portion 78, the fastening portion 76 can fasten the shaft portions 79 of the roller 71 with each other while allowing such declination. Therefore, it is possible to connect a plurality of rollers 71 having manufacturing errors in the connecting portion 72.

  (4) Since the shaft hole forming member 81 constituting the fastening portion 76 has the first notch 81b communicating with the shaft hole 81a formed by the inner peripheral surface thereof, the shaft hole forming member 81 is located at a position close to the first notch 81b. By tightening the bolt 88 inserted into the provided second screw hole 86, the width of the first notch 81b can be narrowed to reduce the diameter of the shaft hole 81a. Therefore, the diameter of the shaft hole 81a is reduced by reducing the diameter of the shaft hole 81a with the end of the first roller 71F and the end of the second roller 71S inserted from both ends of the shaft hole 81a. The ends of the two rollers 71F and 71S can be fastened. Further, the end of the roller 71 inserted into the shaft hole 81a is made to protrude from the shaft hole 81a by projecting the screw 87 screwed into the first screw hole 85 that is paired so as to sandwich the shaft hole 81a. It can be fixed so as not to move relative to 81. Thereby, a rotational force can be reliably transmitted between the 1st roller 71F and the 2nd roller 71S via the fastening part 76. FIG.

  (5) By providing the small diameter portion 79 b in the shaft portion 79, the contact area (contact length) of the shaft portion 79 with respect to the shaft hole forming member 81 in the axial direction of the roller 71 is reduced. For this reason, when the shaft part 79 of the roller 71 is connected, the moment acting on the shaft part 79 of the roller 71 is reduced, and the possibility that the roller 71 is curved can be reduced. As a result, in the transport device 40, a decrease in the transport accuracy of the medium M can be suppressed.

(Second Embodiment)
Hereinafter, a second embodiment of the printing apparatus (conveyance apparatus) will be described with reference to the drawings. In the second embodiment, a fixing structure of the fixing member 75 and the support base 45 that are not described in the first embodiment will be described. Therefore, in description of 2nd Embodiment, about the member structure which is common in 1st Embodiment, the same code | symbol shall be attached | subjected and the description shall be abbreviate | omitted. Moreover, in 2nd Embodiment, even if it is the member structure which attached | subjected the same code | symbol, there is also a member structure which changed the shape slightly for easy understanding of explanation.

As shown in FIG. 11, the transport apparatus 40 according to the second embodiment includes a frame 91 that forms a skeleton of the apparatus, and a fastening mechanism 92 that fastens the frame 91 and the support base 45.
In the frame 91, screw holes 91 b are formed in the wall portion 91 a in contact with the support base 45 in a direction intersecting (orthogonal) with the axial direction of the roller 71 and the conveyance direction Y of the medium M. On the other hand, a through hole 45a having a larger inner diameter than the screw hole 91b is formed in the support base 45 in the same direction as the screw hole 91b in the frame 91. The fixing member 75 is formed with a storage chamber 75a in which the fastening mechanism 92 is stored.

  The fastening mechanism 92 includes a stepped screw 93 having a columnar portion 93 a having a columnar shape and a screw portion 93 b formed with a male screw, and a washer 94 used together with the stepped screw 93. The outer diameter of the columnar portion 93 a of the stepped screw 93 is larger than the inner diameter of the screw hole 91 b of the frame 91 and smaller than the inner diameter of the through hole 45 a of the support base 45. The threaded portion 93 b of the stepped screw 93 can be screwed into the screw hole 91 b of the frame 91.

  On the other hand, the washer 94 has an inner diameter substantially equal to the outer diameter of the cylindrical portion 93 a of the stepped screw 93, and the outer diameter is larger than the inner diameter of the through hole 45 a of the support base 45. In the present embodiment, the washer 94 is a so-called wave washer.

  Then, as shown in FIG. 11, when assembling the transport device 40, the washer 94 was attached with the center of the through hole 45a of the support base 45 and the center of the screw hole 91b of the frame 91 aligned. The stepped screw 93 is inserted into the through hole 45 a of the support base 45 and screwed into the screw hole 91 b of the frame 91. Thus, the support base 45 is sandwiched between the frame 91 and the washer 94, and the support base 45 is fixed to the frame 91.

  However, in this state, since a gap is formed between the through hole 45a of the support base 45 and the cylindrical portion 93a of the stepped screw 93, a force acts on the support base 45 in the axial direction of the roller 71. The support base 45 is allowed to move relative to the frame 91, the stepped screw 93 and the washer 94. Incidentally, the force required for the support base 45 to move relatively is proportional to the fastening force of the stepped screw 93.

  Subsequently, the fixing member 75 is placed on the support base 45 so that the head of the stepped screw 93 is accommodated in the accommodation chamber 75 a, and the fixing member 75 is fixed to the support base 45. Although not illustrated in FIG. 11, the fixing member 75 is fixed to the support base 45 so as not to be relatively movable by a fastening member such as a screw.

  Thereafter, as described in the first embodiment, the shaft portions 79 of the roller 71 are connected to each other by the bearings 73 and 74 fixed to the fixing member 75 and the shaft hole forming member 81. Thus, according to the fastening mechanism 92 of the present embodiment, the support base 45 and the fixing member 75 are fixed to the frame 91 while allowing the support base 45 and the fixing member 75 to move in the axial direction of the roller 71. The member 75 can be fixed.

  In the second embodiment, as shown in FIG. 2, the shaft portion 79 on one end side (right side) of the roller 71 on the one end side (right side) in the scanning direction X (first roller 71) is arranged in the scanning direction X. It shall be supported immovably.

Next, the operation of the printing apparatus 11 of this embodiment will be described.
Now, some printing apparatuses 11 as in the present embodiment include a heating device (an example of a heat source) that heats the medium M before and after printing in order to promote fixing of the ink ejected onto the medium M. In this case, as the heating device heats the medium M, the support base 45 of the transport device 40 may be heated, causing the support base 45 to be thermally deformed. When the support member 45 is thermally deformed (curved) and the fixing member 75 fixed to the support table 45 is displaced in the gravitational direction Z, the roller 71 is bent or the rotation axis center C1 of the adjacent rollers 71 is set. , C2 may not coincide with each other, the conveyance accuracy of the medium M may be reduced.

  In this regard, as shown in FIG. 12, according to the present embodiment, the support base 45 is supported so as to be movable in the axial direction of the roller 71 with respect to the frame 91. For this reason, when a part (right part in FIG. 12) of the support base 45 is heated and thermally deformed, the support base 45 is allowed to be displaced in the axial direction.

  The fixed member 75 fixed to the support base 45 and the bearings 73 and 74 fixed to the fixed member 75 are also displaced in the same manner as the support base 45. However, since the roller 71 on one end side in the scanning direction X is supported so as not to move in the scanning direction X, the displacement of the support base 45 with respect to the roller 71 and other rollers 71 connected to the roller 71 It does not move with it.

  Thus, according to the present embodiment, since the gap (the gap between the through hole 45a of the support base 45 and the columnar portion 93a of the stepped screw 93) in which the support base 45 is displaced in the axial direction of the roller 71 is provided, Thermal deformation of the support base 45 so as to be curved is suppressed. As a result, the fixing member 75 is suppressed from being displaced in the gravity direction Z.

According to the said 2nd Embodiment, in addition to the effect of 1st Embodiment, the following effects can be acquired.
(6) The support base 45 is supported by the frame 91 so as to be movable in the axial direction of the roller 71 with respect to the frame 91. For this reason, even if the support base 45 is heated by the heat source of the printing apparatus 11, since the support base 45 can be displaced in the axial direction of the roller 71, it is possible to suppress thermal deformation so that the support base 45 is curved. . For this reason, the bending of the support base 45 suppresses the displacement of the fixing member 75 in the gravity direction Z, and suppresses the bending of the roller 71 supported by the fixing member 75 via the bearings 73 and 74. Can do.

In addition, you may change the said embodiment like the example of a change shown below. Moreover, the said embodiment and the following modified example can be combined arbitrarily.
When the relative movement in the circumferential direction of the shaft portion 79 and the shaft hole forming member 81 can be suppressed only by the tightening force of the bolt 88, the first screw hole 85 and the screw 87 may not be provided. Alternatively, only one (for example, the screw hole 85B) of the paired first screw holes 85A and 85B may be provided, and the shaft portion 79 may be fixed with one screw 87. On the other hand, when the relative movement in the circumferential direction of the shaft portion 79 and the shaft hole forming member 81 is further suppressed, three or more first screw holes 85 are provided, and the shaft is formed by three or more screws 87 inserted therethrough. The portion 79 may be fixed.

When the shaft hole forming member 81 can be bent by the tightening force of the bolt 88 and the shaft hole 81a can be reduced, the shaft hole forming member 81 need not be provided with the groove 81c.
-The conveyance roller 46 comprised by connecting the some roller 71 like the said embodiment is not restricted to what conveys the medium M toward the printing part 50, For example, the conveyance roller which comprises the paper discharge roller pair 42, for example For example, it may be embodied as a transport roller disposed at an arbitrary position. However, since the conveyance roller 46 that conveys the medium M toward the printing unit 50 requires particularly high conveyance accuracy so as not to cause a shift in the printing position, it is preferable to use the conveyance roller 46 of the present embodiment. .

  In the second embodiment, the through hole 45 a of the support base 45 may be a long hole that is long in the axial direction of the roller 71. According to this, it is possible to prevent the support base 45 from being displaced in the axial direction of the roller 71 with respect to the frame 91, while suppressing the displacement in the direction (conveying direction Y) perpendicular to the axial direction. it can.

  The printing unit 50 may be changed to a so-called full line type printing apparatus that does not include the carriage 52 but includes a long and fixed print head corresponding to the entire width of the medium M. In this case, the print head may be arranged such that a plurality of unit head portions in which nozzles are formed are arranged in parallel so that the print range extends over the entire width of the medium M, or the medium M is formed on a single long head. The printing range may extend over the entire width of the medium M by arranging a large number of nozzles over the entire width.

  Recording materials used for printing include fluids other than ink (liquids, liquids in which particles of functional materials are dispersed or mixed, liquids such as gels, and solids that can be jetted as fluids. ). For example, recording is performed by ejecting a liquid material in which a material such as an electrode material or a color material (pixel material) used for manufacturing a liquid crystal display, an EL (electroluminescence) display, and a surface emitting display is dispersed or dissolved. It may be configured.

  In addition, the printing apparatus is a fluid ejecting apparatus that ejects a fluid such as a gel (for example, a physical gel), or a powder ejecting apparatus that ejects a solid such as a powder (particle) such as toner. For example, a toner jet recording apparatus) may be used. In the present specification, the term “fluid” is a concept that does not include a fluid consisting only of gas. Examples of the fluid include liquid (inorganic solvent, organic solvent, solution, liquid resin, liquid metal (metal melt), etc. ), Liquids, fluids, powders (including granules and powders), and the like.

  The printing apparatus 11 is not limited to a printer that performs recording by ejecting a fluid such as ink, and may be a non-impact printer such as a laser printer, an LED printer, a thermal transfer printer (including a sublimation printer), or a dot impact. An impact printer such as a printer may be used.

The medium is not limited to paper, and may be a plastic film, a thin plate, or the like, or may be a fabric used in a printing apparatus.
The transport device 40 including the transport roller 46 is mounted on the printing device 11, for example, a scanner that reads the transported medium M, a facsimile, a copying device, or a multifunction device including these devices. Also good.

  DESCRIPTION OF SYMBOLS 11 ... Printing apparatus, 40 ... Conveyance apparatus, 46 ... Conveyance roller, 50 ... Printing part, 71, 71F, 71S ... Roller, 71F ... First roller, 71S ... Second roller, 72 ... Connection part, 73 ... First bearing 74 ... second bearing, 75 ... fixing member, 76 ... fastening portion, 78 ... contact portion, 79 ... shaft portion, 79a ... large diameter portion, 79b ... small diameter portion, 81 ... shaft hole forming member, 81a ... shaft hole, 81b: first notch as a notch, 85, 85A, 85B ... first screw hole, 86, 86a, 86b ... second screw hole, 87, 87A, 87B ... screw, 88 ... bolt, M ... medium.

Claims (5)

A transport device that transports a medium by a transport roller including a plurality of rollers aligned along the rotation axis direction and a connecting portion that connects ends of the two rollers aligned in the rotation axis direction,
When the two rollers arranged in the rotation axis direction are the first roller and the second roller, respectively,
A first bearing that supports the end of the first roller in a rotatable state;
A second bearing that supports the end of the second roller in a rotatable state;
A fixing member to which the first bearing and the second bearing are fixed;
A fastening portion that is disposed between the first bearing and the second bearing in the rotation axis direction and fastens the end portion of the first roller and the end portion of the second roller;
A conveying device comprising: The roller has a shaft portion located at an end portion in the rotation axis direction,
The fastening portion has the shaft portion of the first roller and the shaft portion of the second roller in a state in which a deviation between the rotation shaft center of the first bearing and the second bearing and the rotation shaft center of the shaft portion is allowed. The conveying device according to claim 1, wherein the transfer device can be fastened. The roller has a shaft portion located at an end portion in the rotation axis direction,
The shaft portion includes a large-diameter portion that can come into contact with the fastening portion when fastened by the fastening portion, and a small-diameter portion having an outer diameter smaller than that of the large-diameter portion. 2. The transfer apparatus according to 2. The fastening portion includes a shaft hole forming member having a cylindrical shape and an inner peripheral surface forming a shaft hole,
The shaft hole forming member communicates with the shaft hole and is arranged to face the cylindrical portion in a pair so as to sandwich the shaft hole with a notch formed in the cylindrical portion so as to extend in the rotation axis direction. A first screw hole extending in a direction crossing the rotation axis direction, and a second screw hole provided at a position closer to the notch than the first screw hole,
By tightening a bolt that is screwed into the second screw hole, the diameter of the shaft hole can be reduced,
The conveying device according to any one of claims 1 to 3, wherein the two screws that are screwed into the first screw hole can project into the shaft hole. The conveying apparatus as described in any one of Claims 1-4,
A printing unit that performs printing on the medium conveyed by the conveying device;
A printing apparatus comprising:

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