JP2009179442A - Roller unit and sheet member separating and feeding mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller unit and a sheet member separating and feeding mechanism improved in durability. <P>SOLUTION: In a retard roller 13 (roller unit) comprising a roller shaft 24, a coil spring 25 wound around the outer periphery of the rotor shaft, and a roller part 23 loosely fitted to the outer periphery of the roller shaft with the coil spring intervened therebetween, and constructed so that relative rotation of the roller part to one direction with respect to the roller shaft is allowed whereas relative rotation of the roller part to the other direction with respect to the roller shaft is prevented as the coil spring windingly tightens around the roller shaft, the roller shaft is made of metal and a recessed part 48 capable of retaining lubricant is formed in a winding position of the coil spring in the outer peripheral face of the roller shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a roller unit and a sheet member separation and supply mechanism, and in particular, a roller unit that feeds sheet members such as a plurality of recording sheets supported in a stacked state one by one from the uppermost one, and The present invention relates to a sheet member separation and supply mechanism.

  For example, in a recording apparatus such as a printer, a copying machine, or a facsimile, a feeding apparatus (auto sheet) capable of setting a plurality of recording sheets (a type of sheet member, hereinafter abbreviated as sheets) as a recording medium. Feeder) is provided. For example, the feeding device switches between a feeding roller that feeds the paper downstream by rotating in contact with the paper, and a posture that supports the paper and presses the supported paper against the feeding roller, and a posture that separates the paper. It is equipped with a hopper that can be used and a separation mechanism that separates the paper that is to be double fed during feeding, and feeds a plurality of sheets supported by the hopper in a stacked state one by one from the top. (For example, patent document 1).

  Here, a retard roller (separation roller) as shown in Patent Document 1 may be used as the separation mechanism. The retard roller is provided in a state where a predetermined rotational resistance (torque) is applied, and more specifically, when a torque exceeding a predetermined value is applied to the retard roller, there is no paper between the feed roller and the retard roller. Or when only one sheet exists, it rotates following the feeding roller. Conversely, when the torque applied to the retard roller becomes less than a predetermined value, more specifically, when two or more sheets exist between the feed roller and the retard roller, the follower is driven by the feed roller. Does not rotate. As a result, the succeeding and subsequent sheets that are to be double-fed along with the uppermost sheet to be fed stay on the retard roller, and the double feeding of the sheets is prevented.

JP 2007-254154 A

  The retard roller is loosely fitted to the outer periphery of the roller shaft with a shaft portion (roller shaft) supported in a fixed state on the holder, a coil spring wound around the outer periphery of the roller shaft, and the coil spring interposed therebetween. Some of them are composed of a roller portion. The retard roller is allowed to rotate relative to the roller shaft in one direction. At the time of rotation in this one direction, the roller portion is urged in the other direction by the coil spring, and this urging force becomes the rotation resistance described above. On the other hand, relative rotation of the roller portion with respect to the roller shaft in the other direction is prevented by winding the coil spring around the roller shaft.

  As a material for a roller shaft in a conventional retard roller, Zylon (registered trademark), which is a fiber in which polyparaphenylene benzobisoxazole (PBO) is subjected to liquid crystal spinning, is preferably used. However, since the coil spring slides on the roller shaft along with the rotation of the roller portion, there are cases where seizure occurs at the sliding portion between the roller shaft and the coil spring, and the coil spring is damaged. In addition, since the sliding portion of the roller shaft with the coil spring is worn, a necessary rotational resistance cannot be ensured, and there is a possibility that the paper cannot be normally separated.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a roller unit and a sheet member separation and supply mechanism that can improve durability.

The roller unit of the present invention has been proposed in order to achieve the above-described object, and includes a roller shaft, a coil spring wound around the outer periphery of the roller shaft, and an outer periphery of the roller shaft with the coil spring interposed therebetween. A loosely fitted roller section,
While the roller portion is allowed to rotate in one direction with respect to the roller shaft, relative rotation of the roller portion in the other direction with respect to the roller shaft is prevented by the coil spring being wound around the roller shaft. A roller unit configured as follows:
The roller shaft is made of metal, and a recess capable of holding a lubricant is formed at the winding position of the coil spring on the outer peripheral surface of the roller shaft.

  According to the above configuration, the roller shaft is made of metal, and the recess that can hold the lubricant is formed at the winding position of the coil spring on the outer peripheral surface of the roller shaft. The seizure and wear can be suppressed, thereby improving the durability. As a result, the reliability of the roller unit can be improved.

  The said structure WHEREIN: It is desirable to produce the said roller axis | shaft by shape | molding a metal plate material to a cylindrical shape by press work.

  According to the above configuration, the roller shaft can be produced by molding the metal plate material into a cylindrical shape by press working, so that it becomes possible to improve productivity. Moreover, it is possible to contribute to a reduction in production cost.

Further, a sheet member separation and supply mechanism of the present invention includes the roller unit having the above-described configuration and a feed roller provided in a pair with the roller unit,
The rotational resistance of the coil spring during rotation in one direction of the roller portion relative to the roller shaft is set to be smaller than the rotational torque of the feeding roller,
In a state where one sheet member from the sheet member supply source is held between the roller unit and the feeding roller, the roller unit is rotated in the one direction following the rotation of the feeding roller. While the sheet member is fed to the downstream side, when a plurality of sheet members from the sheet member supply source are nipped by the roller unit and the feeding roller, the rotation of the roller unit is stopped and the sheet is fed most. Only the sheet member located on the roller side is fed downstream by the rotation of the feeding roller.

  According to the above configuration, the roller shaft is made of metal, and the recess that can hold the lubricant is formed at the winding position of the coil spring on the outer peripheral surface of the roller shaft. The seizure and wear can be suppressed, thereby improving the durability. As a result, the reliability of the sheet member separation and supply mechanism can be improved.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the following description, a configuration in which the roller unit and the sheet member separation and supply mechanism in the present invention are applied to an ink jet recording apparatus (hereinafter simply referred to as a printer) that is an embodiment of the liquid ejecting apparatus will be exemplified.

  FIG. 1 is a perspective view of the main body of the printer 1 (with the exterior cover removed), and FIG. 2 is a schematic cross-sectional view of the side of the printer 1. The printer 1 is provided with a rear feeding device 2 at the rear of the apparatus and a front feeding device 3 at the bottom of the apparatus, and recording paper (hereinafter referred to as paper P) as a sheet member from these two feeding devices 2 and 3. Is fed to the paper feed mechanism 5. The paper P is fed to the recording head 4 side by the paper feeding mechanism 5, recording is performed, and then discharged to the stacker 7 by the discharge mechanism 6.

  The rear feeding device 2 includes a frame 10 constituting a base of the device, a hopper 12 (a kind of sheet member supply source in the present invention), a feeding roller 11, and a retard roller 13 (a kind of roller unit in the present invention). And a return lever 19, a support plate 21, a movable edge guide 17, and a fixed edge guide 16.

  The hopper 12 is formed of a plate-like body, and is provided so as to be able to oscillate about an upper oscillating fulcrum 12a. The hopper 12 presses the paper P supported on the hopper 12 in an inclined posture against the feeding roller 11; The separation posture for separating P from the feeding roller 11 is switched. A front end abutting surface 10a against which the front end of the paper P abuts is provided at a position facing the lower end of the hopper 12, and the front end of the set paper P slides on the front end abutting surface 10a as the hopper 12 swings. The contact roller 11 is moved toward and away from the feeding roller 11 while being in contact. A guide surface 10b is provided on the downstream side of the feed roller 11, and the paper P from the feed roller 11 is conveyed downstream while being guided by the guide surface 10b.

FIG. 3 is a side view illustrating the configuration of the sheet member separation and supply mechanism including the feeding roller 11 and the retard roller 13.
The feeding roller 11 is a member formed in a cylindrical shape by an elastic material, and is pressed against the hopper 12 by rotating counterclockwise in FIG. 3 about a shaft 11 ′ by a driving force by a driving motor (not shown). The uppermost sheet P (most feed roller 11 side) is fed downstream. The retard roller 13 is provided so as to be able to come into pressure contact with the feeding roller 11 and functions as a separating unit for preventing the double feeding of the paper P. This retard roller 13 includes a roller portion 23 and a roller shaft 24 provided in a holder 18, and the roller portion 23 is rotated by a coil spring 25 to be described later when a sheet is fed (one direction indicated by an arrow A in FIG. 3). ) In the opposite direction (the other direction indicated by arrow B in FIG. 3) in a state where a predetermined rotational resistance is applied.

  The rotational resistance by the coil spring 25 when the roller portion 23 rotates in one direction with respect to the roller shaft 24 is set to be smaller than the rotational torque of the feeding roller 11. When there is no sheet P between the feeding roller 11 and the retard roller 13 or when only one sheet P exists between the feeding roller 11 and the retard roller 13, the roller unit 23 is It rotates in one direction indicated by an arrow A following the rotation of the feeding roller 11 while resisting rotational resistance. On the other hand, when there are a plurality of sheets P between the feeding roller 11 and the retard roller 13, the roller portion 23 is stopped from rotating at the initial position due to the sliding action between the sheets. In the case of rotating in one direction until just before, the state is returned to the initial position in the other direction indicated by the arrow B and rotated and stopped. As a result, only the uppermost sheet P positioned closest to the feeding roller 11 is fed downstream by the rotation of the feeding roller 11. In this way, double feeding of the paper P is prevented.

  The retard roller 13 is provided in the frame 10 constituting the base of the rear feeding device 2 so as to be able to advance and retreat with respect to the feeding roller 11, and as shown in FIG. The roller portion 23 is urged with respect to the feeding roller 11 as a center. That is, the roller portion 23 is pressed against the feeding roller 11 by the biasing force of the biasing spring 9, and a nip point between both rollers is formed. The retard roller 13 is provided so as to be directly engageable with the hopper 12, and the roller portion 23 is configured to advance and retract with respect to the feeding roller 11 in conjunction with the swinging operation of the hopper 12. Yes. The details of the retard roller 13 will be described later.

  The return lever 19 provided in the vicinity of the feeding roller 11 and the retard roller 13 has a generally U-shape when viewed from the side, and is provided so as to be rotatable about a rotation shaft 20. The return lever 19 is rotated so that the leading edge of the next and subsequent sheets P to be double-fed along with the uppermost sheet P to be fed is upstream, that is, the leading end support surface 10a. It is configured to return to the side.

  The support plate 21 (see FIG. 1) supports the rear end portion of the paper P by extending the paper support surface of the hopper 12 toward the rear end of the paper P. The movable edge guide 17 and the fixed edge guide 16 are provided so as to face each other in the hopper 12 and abut the edge of the paper P to regulate the position of the paper P. Among these guides, the movable edge guide 17 is provided in the hopper 12 so as to be slidable in the width direction of the paper P, and can thereby be displaced to an appropriate position suitable for the width dimension of the paper P. Yes.

On the other hand, the front feeding device 3 provided at the bottom of the printer 1 and configured to set paper from the front of the device has a paper feeding cassette 37, a pickup roller 27, a feeding roller 28, and a retard roller 29 (main book). A kind of roller unit in the invention).
A plurality of paper sheets P can be set in a stacked state in a paper feed cassette 37 that can be loaded and removed from the front side of the apparatus. The pickup roller 27 that is rotationally driven by a motor (not shown) rotates in contact with the uppermost sheet P of paper P set in the paper feeding cassette 37, thereby feeding the uppermost paper P from the paper feeding cassette 37. Further, the feeding roller 28 curves and reverses the uppermost sheet P fed from the sheet feeding cassette 37 and feeds it to the sheet feeding mechanism 5 through the guide plate 34. The feeding roller 28 and the retard roller 29 in the front feeding device 3 have the same configuration as the feeding roller 11 and the retard roller 13 in the rear feeding device 2.

  On the downstream side of the rear feeding device 2 and the front feeding device 3, paper detection means (not shown) for detecting the passage of the paper P, and the feeding posture of the paper P fed from the rear feeding device 2 And a guide plate 34 that guides the fed paper P to the paper feed mechanism 5.

  The paper feeding mechanism 5 includes a feeding driving roller 32 that is rotationally driven by a motor, and a feeding driven roller 33 that is driven to rotate while being pressed against the feeding driving roller 32. The paper P that has reached the paper feed mechanism 5 is disposed below the recording head 4 by rotating the feed drive roller 32 while being nipped by the feed drive roller 32 and the feed driven roller 33. It is conveyed onto the platen 38.

  The recording head 4 is provided at the bottom of the carriage 35. The carriage 35 is guided by a carriage guide shaft 36 extending in the main scanning direction, and performs a recording operation (ink ejection operation) on the paper P conveyed downward while reciprocating in the main scanning direction by a drive motor (not shown). Is configured to do. The carriage 35 is equipped with an independent ink cartridge (not shown) for each of a plurality of colors, and ink is supplied from the ink cartridge to the recording head 4.

  A platen 38 is provided at a position facing the recording head 4, and the distance between the paper P and the recording head 4 is defined by the platen 38. On the downstream side of the recording head 4, an auxiliary roller 41 that prevents the paper P from floating from the platen 38 and a discharge mechanism 6 that discharges the paper P on which recording has been performed are provided. The discharge mechanism 6 includes a discharge drive roller 39 that is rotationally driven by a motor (not shown), and a discharge driven roller 40 that rotates in contact with the discharge drive roller 39. The paper P on which recording (ink discharge) of images, texts, and the like has been performed by the recording head 4 is driven by the discharge drive roller 39 being rotated while being nipped by the discharge drive roller 39 and the discharge driven roller 40. Then, it is discharged to a stacker 7 provided on the front side of the apparatus.

Next, the retard roller according to the present invention will be described in detail. Since the retard roller 13 of the rear feeding device 2 and the retard roller 29 of the front feeding device 3 have the same configuration, the following description will be made on behalf of the retard roller 13 of the rear feeding device 2. To do.
4A and 4B are diagrams for explaining the configuration of the retard roller 13. FIG. 4A is a plan view of the retard roller 13 with the roller portion 23 removed, and FIG. 4B is a retard roller 13 with the roller portion 23 attached. (C) is a side view of the retard roller 13 with the roller portion 23 attached.

  The retard roller 13 in this embodiment includes a roller shaft 24, a coil spring 25 wound around the outer periphery of the roller shaft 24, and a roller portion 23 loosely fitted on the outer periphery of the roller shaft 24 with the coil spring 25 interposed therebetween. Are attached to the holder 18. The holder 18 includes a holding portion 18a that holds the roller shaft 24 and the roller portion 23, and an arm portion 18b that protrudes behind the holding portion 18a.

  The holding portion 18a has a pair of holding walls 44a and 44b arranged to face each other at a predetermined interval, and the roller shaft 24, the coil spring 25, and the roller portion 23 are held between the holding walls 44a and 44b. It has come to be. The holding walls 44a and 44b are provided with holding holes 45a and 45b each having a size that is a slightly enlarged cross-sectional shape at both ends in the longitudinal direction of the roller shaft 24. The holding holes 45a and 45b are respectively provided with the roller shaft 24. The roller shaft 24 is attached to the holding portion 18a by engaging and locking both end portions from the inside. That is, the roller shaft 24 is held in a state where it cannot rotate with respect to the holder 18. As will be described later, the cross-sectional shapes of both end portions in the longitudinal direction of the roller shaft 24 are different from each other, and accordingly, the holding holes 45a and 45b have an opening shape following the both end shapes of the corresponding roller shaft 24. Presents. Thereby, when attaching the roller shaft 24 to the holding | maintenance part 18a, it can prevent that an operator mistakes the attachment direction of the roller shaft 24. FIG.

  The arm portion 18b is a member having a substantially triangular shape in a side view protruding rearward from the central portion in the longitudinal direction of the holding portion 18a, and is formed integrally with the holding portion 18a. The arm portion 18b includes a swing shaft 26 that is rotatably supported by the frame 10, and a hook 46 that is provided at a position that is approximately 90 ° out of phase with the holding portion 18a around the swing shaft 26. have. One end of the biasing spring 9 attached to the frame 10 is locked to the hook 46. Accordingly, as described above with reference to FIG. 3, the roller portion 23 held by the holding portion 18 a about the swing shaft 26 is urged against the feeding roller 11 by the urging spring 9. It has become.

5A and 5B are diagrams illustrating the configuration of the roller shaft 24. FIG. 5A is a top view of the roller shaft 24, FIG. 5B is a cross-sectional view taken along the line bb in FIG. 5A, and FIG. FIG. 4D is a rear view of the roller shaft 24, FIG. 4E is a right side view of the roller shaft 24, and FIG.
The roller shaft 24 is manufactured by molding a metal plate material into an elongated cylindrical shape having a substantially circular cross section. In this embodiment, it is formed into a cylindrical shape by press working using a galvanized steel sheet.

  Notches 47a and 47b are formed on the back side of both ends in the longitudinal direction of the roller shaft 24, respectively. The shapes and dimensions of the notches 47a and 47b are different at both ends, and as a result, the cross-sectional shapes at both ends in the longitudinal direction of the roller shaft 24 are made different as described above. A recess 48 capable of holding a lubricant such as grease is formed at the winding position of the coil spring 25 on the outer peripheral surface of the roller shaft 24. The recess 48 in the present embodiment is a groove-like recess (oil groove) elongated in the longitudinal direction of the roller shaft 24, and is in the middle of the thickness direction from the surface of the roller shaft 24 (for example, about the plate thickness). 50%).

  Thus, by providing the recess 48 at the winding position of the coil spring 25 and holding the lubricant in the recess 48, the lubricity when the coil spring 25 slides on the roller shaft 24 can be improved. . Thereby, the seizure at the sliding portion can be suppressed, and problems such as breakage of the coil spring 25 can be prevented. Further, it is possible to suppress wear of the sliding portion of the roller shaft 24 with the coil spring 25. As a result, the necessary rotational resistance can be ensured, and as a result, the reliability of the retard roller 13 can be improved. In addition, the shape of the recessed part 48 is not restricted to what was illustrated, Various shapes can be employ | adopted as needed. A plurality of recesses 48 can be provided at the sliding portion of the roller shaft 24 with the coil spring 25.

Next, a process for forming the roller shaft 24 will be described.
FIGS. 6A to 6C are diagrams for explaining a process of forming a cylinder that becomes the roller shaft 24 from a metal substrate by pressing, and FIGS. 7A to 7C are diagrams illustrating the metal in each process of FIG. It is sectional drawing explaining the shape of a board | substrate made. First, a substrate 51 having a size and shape necessary for forming the roller shaft 24 is obtained by blanking the galvanized steel sheet, which is a metal material in the present embodiment. If the board | substrate 51 is obtained, said notch 47a, 47b and the recessed part 48 will be formed.
Subsequently, the substrate 51 is formed into a cylindrical shape through a total of three steps including the following first press step to third press step.

  As shown in FIG. 6A and FIG. 7A, in the first pressing step, P is removed from the portion corresponding to A in FIG. A region corresponding to up to 90 ° on both sides is formed as a center. That is, by pressing the first male mold 53a from the upper side of the substrate 51 toward the first female mold 54a side with the substrate 51 placed on the first female mold 54a, the base material 51 corresponds to the arc A. Process the part to bend inward. Subsequently, as shown in FIG. 6B and FIG. 7B, the process proceeds to the second pressing step, and the portion corresponding to the arc B in FIG. On the other hand, a region corresponding to a position from the opposite side of 180 ° with respect to P to 45 ° on both sides is molded. That is, with the substrate 51 formed with the arc A placed on the second female die 54b, the second male die 53b is lowered and pressed from above the substrate 51 toward the second female die 54b. Thus, a portion corresponding to the arc B is processed on the substrate 51. Once the arcs A and B have been processed, a core bar 55 having a perfectly circular cross section is inserted inside the bent base material 51, and the third press as shown in FIGS. 6 (c) and 7 (c). In the process, the portion corresponding to the arc C (the arc between the arc A and the arc B) is molded. That is, in a state where the substrate 51 with the cored bar 55 inserted is placed on the third female mold 54c, the third male mold 53c is lowered from above the substrate 51 and pressed, whereby the substrate 51 is moved to the cored bar. It is molded into a cylindrical shape following the outer peripheral shape of 55.

  In this way, the roller base 24 is formed by molding the metallic substrate 51 into a cylindrical shape by pressing. Thereby, it becomes possible to improve productivity compared with the structure which produces a roller axis | shaft by injection molding or grinding. Moreover, it is possible to contribute to a reduction in production cost.

  Further, since the roller shaft 24 is made of metal, and the recess 48 that can hold the lubricant is formed at the winding position of the coil spring 25 on the outer peripheral surface of the roller shaft 24, the sliding between the roller shaft 24 and the coil spring 25 is formed. It is possible to suppress seizure and wear due to movement, thereby improving durability. As a result, the reliability of the sheet member separation and supply mechanism can be improved.

  In the above, the configuration in the case where the roller unit and the sheet member separation and supply mechanism according to the present invention are applied to the printer 1 has been exemplified. However, the configuration is not limited to this, and the sheet-like member is fed one by one. If so, it can be used for other devices. For example, it can also be used for feeding copier or facsimile paper. Moreover, it is suitable also for the use which feeds banknotes, such as an automatic cash dispenser (ATM).

FIG. 2 is a perspective view illustrating a configuration of a printer. 2 is a side cross-sectional view illustrating a configuration of a printer. FIG. It is a schematic diagram explaining the structure of a sheet | seat member separation supply mechanism. (A)-(c) is a figure explaining the structure of a retard roller. (A)-(f) is a figure explaining the structure of a roller axis | shaft. (A)-(c) is a figure explaining the process of forming the cylinder used as a roller axis | shaft by press work. (A)-(c) is sectional drawing explaining the shape of the board | substrate in each press process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Rear feeding device, 3 ... Front feeding device, 4 ... Recording head, 11 ... Feeding roller, 13 ... Retard roller, 18 ... Holder, 23 ... Roller part, 24 ... Roller shaft, 25 ... Coil spring, 44 ... holding wall, 45 ... holding hole, 46 ... hook, 47 ... notch, 48 ... depression

Claims (3)

A roller shaft, a coil spring wound around the outer periphery of the roller shaft, and a roller portion loosely fitted on the outer periphery of the roller shaft with the coil spring interposed therebetween,
While the roller portion is allowed to rotate relative to the roller shaft in one direction, the roller portion rotates relative to the roller shaft in the other direction because the coil spring is wound around the roller shaft. A roller unit configured to be blocked,
A roller unit, wherein the roller shaft is made of metal, and a recess capable of holding a lubricant is formed at a winding position of the coil spring on an outer peripheral surface of the roller shaft.   The roller unit according to claim 1, wherein the roller shaft is manufactured by molding a metal plate material into a cylindrical shape by pressing. The roller unit according to claim 1 or 2, and a feed roller provided in a pair with the roller unit,
The rotational resistance by the coil spring at the time of relative rotation in one direction of the roller portion with respect to the roller shaft is set to be smaller than the rotational torque of the feeding roller,
In a state where one sheet member from the sheet member supply source is held between the roller unit and the feeding roller, the roller unit is rotated in the one direction following the rotation of the feeding roller. While the sheet member is fed to the downstream side, when a plurality of sheet members from the sheet member supply source are nipped by the roller unit and the feeding roller, the rotation of the roller unit is stopped and the sheet is fed most. A sheet member separation and supply mechanism configured to feed only a sheet member positioned on a roller side to a downstream side by rotation of a feeding roller.

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