JP2010242928A - Recording device - Google Patents

Abstract

An object of the present invention is to more effectively reduce twisting of a rotating shaft without increasing the diameter or increasing its own weight.
A roller rotation shaft 20 is provided with a gear 14 at one end thereof and transmits rotational torque to a gear 15 provided at the other end. The roller rotation shaft 20 is made of a resin material, and on the outer periphery thereof, a spiral rib that rotates along the rotation axis and an auxiliary rib that extends along the circumferential direction connecting adjacent spiral ribs. Are integrally formed by resin molding. By the helical rib, the torsional rigidity of the roller rotating shaft 20 can be improved, and the amount of twisting (twisting angle) can be suppressed.
[Selection] Figure 4

Description

  Rollers are provided everywhere on a conveyance path for conveying a recording sheet in a recording apparatus typified by a facsimile or a printer. A torque of the motor is applied to one end of a rotating shaft of the roller that is rotationally driven by the motor (hereinafter referred to as “roller rotating shaft”), and the roller rotating shaft transmits the torque to the roller.

  In this way, the roller rotation shaft transmits torque from the motor to the roller. However, since the roller receives rotation resistance, the rotation resistance and torque from the motor cause twisting of the roller rotation shaft. In particular, a roller rotating shaft formed by resin molding for the purpose of cost reduction is more likely to be twisted.

  When the roller rotation shaft is twisted, the accuracy of the paper feed control is lowered, and as a result, the recording quality is lowered. Further, for the purpose of cost reduction, the roller rotation shaft may be configured to also serve as a power transmission shaft for another drive target. In such a case, twisting of the roller rotation shaft causes a phase delay when power is transmitted to the other drive target, and the desired control cannot be performed accurately.

  On the other hand, if the shaft diameter is increased in order to prevent such twisting, the weight of the roller rotation shaft increases, which requires large torque to rotate due to the deflection of the roller rotation shaft and increased inertia. There is a possibility that a new problem will occur. Therefore, it has been conventionally performed to locally provide a twist suppressing portion (thick diameter portion) as shown in Patent Document 1 on the roller rotation shaft.

JP 2003-72962 A

Since the twist suppressing portion (large diameter portion) as shown in Patent Document 1 is provided only at a specific portion of the roller rotation shaft, twist is still generated in other portions, and the occupied space is occupied by the large diameter portion. Had the disadvantage of becoming larger.
Accordingly, the present invention has been made in view of such a situation, and an object thereof is to more effectively reduce the twist of the rotating shaft without increasing the diameter or increasing the dead weight.

  In order to solve the above-mentioned problem, a first aspect of the present invention is a rotating shaft that is rotated by a rotational torque applied from a power source, and has a spiral rib that rotates on the outer periphery along a rotation axis. It is provided integrally.

  According to this aspect, the rotating shaft that is rotated by being applied with the rotational torque from the power source is integrally provided with the spiral rib that rotates along the rotation axis center line on the outer periphery. And the twist amount (twist angle) of the rotating shaft can be suppressed.

  The second aspect of the present invention is characterized in that, in the first aspect, auxiliary ribs extending in the circumferential direction are integrally provided to connect the adjacent spiral ribs. According to this aspect, the auxiliary ribs extending along the circumferential direction that connect the adjacent spiral ribs are integrally provided, so that the torsional rigidity of the rotating shaft is further improved, and the rotating shaft is twisted. The amount (twist angle) can be further suppressed.

  According to a third aspect of the present invention, in the first or second aspect, an angle formed by the spiral rib and a plane orthogonal to the rotation axis is 45 °. According to this aspect, since the angle formed by the spiral rib and the surface orthogonal to the rotation axis is 45 °, the torque applied to the rotation shaft is in any rotation direction. The torsional rigidity can be improved.

  According to a fourth aspect of the present invention, there is provided a feeding roller that feeds a recording medium by rotating in contact with the recording medium, and a motor that is attached to the feeding roller and that is a drive source of the feeding roller. And a rotating shaft according to any one of the first to third aspects for transmitting torque to the feeding roller. According to this aspect, in the recording apparatus, it is possible to obtain the same effect as any one of the first to third aspects.

FIG. 3 is a side sectional view showing a paper conveyance path of the printer according to the invention. FIG. 3 is a side sectional view showing a paper conveyance path of the printer according to the invention. The perspective view of a paper feeding part. The perspective view of the roller rotating shaft which concerns on this invention. (A) is a diagram in which the outer peripheral surface of the roller rotation shaft whose rib inclination angle is set to 0 ° is developed in a plane, and (B) is a diagram in which the outer periphery of the roller rotation shaft having a predetermined rib inclination angle is developed in a plane. .

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Here, FIGS. 1 and 2 are side sectional views showing a sheet conveyance path of an ink jet printer 1 as an example of a recording apparatus according to the present invention, FIG. 3 is a perspective view of a sheet feeding unit 2, and FIG. FIG. 5A is a perspective view of the roller rotation shaft 20 according to the embodiment, FIG. 5A is a diagram in which the outer peripheral surface of the roller rotation shaft (comparative example) whose rib inclination angle is set to 0 ° is developed on a plane, and FIG. It is the figure which expand | deployed the outer peripheral surface of the roller rotating shaft 20 which concerns on this invention to a plane which has the said rib inclination angle.

  In the following, in FIG. 1, in the sheet conveyance path from the intermediate roller 24 to the discharge drive roller 47, the right direction in the figure is referred to as the “downstream side” of the sheet conveyance path, and the left direction in the figure is the “upstream side” in the sheet conveyance path. I will say.

  In FIG. 1, the ink jet printer 1 includes a paper feeding unit 2 at the bottom of the apparatus. The paper P is fed from the paper feeding unit 2 and is bent and reversed by the paper feeding roller unit 3 to be fed toward the recording head 37. It has a configuration for sending and recording. In FIG. 1, a broken line R1 indicates the transport route (passage trajectory) of the paper P at this time.

  The ink jet printer 1 records on the first surface (front surface) of the paper P, then back feeds it, feeds it to the paper feed roller unit 3 and reverses it, with the second surface (back surface) facing up. Thus, it can be conveyed again to the recording head 37 side. That is, both sides recording is possible, and the broken line R2 in FIG. 2 indicates the transport route (passage trajectory) of the paper P at this time.

  Reference numeral 4 denotes a scanner unit provided in the upper part of the printer mechanism unit, and the ink jet printer 1 is configured as a so-called multi-function machine that can print out a document image read by the scanner unit 4 by the lower printer mechanism unit. Has been.

  Hereinafter, the configuration of the sheet conveyance path will be described in detail. The paper feeding unit 2 includes a paper cassette 11 and a feeding roller 18. The paper cassette 11 detachable from the apparatus main body is provided with an edge guide (not shown), and the edge guide regulates the side edge position and the rear edge position of the paper P stored in the paper cassette 11. It is like that.

  A separation slope 12 is provided at a position facing the leading edge of the paper P accommodated in the paper cassette 11, and the leading edge of the paper P sent out by the feeding roller 18 is fed to the downstream side while being in sliding contact with the separation slope 12. By doing so, preliminary separation is performed between the uppermost sheet P to be fed and the next and subsequent sheets P to be double-fed.

  The feed roller 18 is pivotally supported by a swinging member 19 that can swing in the clockwise and counterclockwise directions of FIGS. The feeding roller 18 receives the power of a driving motor (not shown) via the roller rotating shaft 20 and the toothed wheel train 16 and is driven to rotate. When the paper is fed, the feeding roller 18 rotates in contact with the uppermost paper P stored in the paper cassette 11 to feed the uppermost paper P from the paper cassette 11.

  In the present embodiment, the feeding roller 18 is configured to be separated from the uppermost sheet P during non-feeding (while waiting for feeding), but the uppermost sheet is also used during non-feeding. It can also be configured to be in pressure contact with P.

  A friction pad 13 is provided at a position facing the feeding roller 18 on the bottom surface 11 a of the paper cassette 11, and when the feeding roller 18 is pressed against the sheet bundle from above, the lowest sheet P is the friction pad 13. When pressed toward the front, the sheet bundle is held so that the sheet bundle is not sent out.

  The paper P fed upward from the paper cassette 11 enters the paper feed roller unit 3. The paper feed roller unit 3 includes a reverse roller 22, a retard roller 23, an intermediate roller 24, and a guide member 25.

  The reversing roller 22 is a large-diameter roller that forms the inside of the path for reversing the curvature of the paper P. In this embodiment, the reversing roller 22 is centered in the paper width direction (the front and back sides of the paper surface in FIGS. One ink jet printer 1 is disposed at the feeding reference position. The reverse roller 22 is provided so as to be rotationally driven by the power of a drive motor (not shown), and conveys the paper P downstream by rotating in the clockwise direction in FIGS. 1 and 2.

  The retard roller 23 is provided so as to be capable of being pressed against the reversing roller 22 in a state where a predetermined rotational frictional resistance is applied. The upper sheet P is separated from the next and subsequent sheets P which are to be double fed along with the upper sheet P.

  Note that a paper return lever 17 (not shown) is provided in the vicinity of the paper feed path, and the next and subsequent sheets of paper P whose progress has been stopped by the retard roller 23 are fed to the paper cassette by the paper return lever. 11 to return to 11.

  The intermediate roller 24 is a freely rotatable roller, and assists the paper feeding by the reversing roller 22 by nipping the paper P with the reversing roller 22. The guide member 25 is located between the reversing roller 22 and the conveyance driving roller 40, and forms an upper path and a lower path through which the paper P on which recording has been performed on the first surface is fed back. To do.

  Next, on the downstream side of the intermediate roller 24, a first transport unit configured to include a transport driving roller 40 and a transport driven roller 41 is provided. In the present embodiment, the conveyance drive roller 40 is formed by attaching wear-resistant particles to the surface of a metal shaft that is long in the paper width direction, and is driven to rotate by a drive motor (not shown). In the present embodiment, the transport driven roller 41 is formed of a resin material, and a plurality of the transport driven rollers 41 are arranged along the longitudinal direction of the transport driving roller 40 with appropriate intervals.

  The transport driven roller 41 is pivotally supported on the paper guide 30 as a roller support so as to be freely rotatable, and is provided so as to be in pressure contact with the transport driving roller 40. Nip.

  The paper guide top 30 that supports the transport driven roller 41 is swingably supported by the frame 33 via the swing shaft 30a, and a tension spring that exerts a biasing force between the frame 33 and the paper guide top 30. 31, the conveyance driven roller 41 is provided in a state of being urged in a direction in which the conveyance driven roller 41 is pressed against the conveyance driving roller 40. In the present embodiment, a plurality (three in this embodiment) of the paper guides 30 are arranged along the axial direction of the transport driving roller 41.

  Next, on the downstream side of the transport driving roller 40, an ink jet recording head 37 and a paper guide front 45 are vertically opposed to each other. The ink jet recording head 37 is provided at the bottom of the carriage 36, and the carriage 36 is guided by the frames 33 and 34 disposed in the front and rear, and receives the power of a driving motor (not shown) to receive the power of the driving motor (not shown). 2 in the direction of the front and back of the paper). The carriage 36 houses a cartridge not shown.

  Ribs 45a, 45b, and 45c extending in the paper transport direction are arranged at predetermined intervals in this order from the upstream side to the downstream side in the paper transport direction on the surface facing the ink jet recording head 37 before the paper guide 45. A plurality of ribs are provided at appropriate intervals in the main scanning direction (arrangement in the main scanning direction is not shown). The paper P is supported by these ribs, and the distance from the ink jet recording head 37 is defined.

  Next, an auxiliary roller 46 for preventing sheet lifting is provided on the downstream side of the region where the ink jet recording head 37 and the paper guide front 45 are opposed to each other, and further on the downstream side, a discharge driving roller that constitutes a second transport unit. 47 and a discharge driven roller 48 are provided. The discharge drive roller 47 is composed of a rubber roller and is rotationally driven by a drive motor (not shown). The discharge driven roller 48 is a spur provided so as to be lightly elastically contacted with the discharge drive roller 47, and nips the paper P with the discharge drive roller 47. The paper P on which recording has been performed by these rollers is discharged toward a stacker (not shown).

The above is the configuration of the paper transport path of the inkjet printer 1, and the roller rotating shaft 20 provided in the paper feeding unit 2 will be described in detail below with reference to FIGS.
The roller rotation shaft 20 is arranged in parallel with the paper width direction of the paper P accommodated in the paper cassette 11, and a gear 14 is provided at one end portion thereof.

  The gear 14 meshes with a gear (not shown) driven by a motor (not shown) as a drive source, and applies a rotational torque to the roller rotating shaft 20. A gear 15 is provided at the other end of the roller rotating shaft 20, and the gear 15 meshes with the above-described toothed wheel train 16 and transmits the rotational torque of the motor to the feeding roller 18. In this embodiment, the gears 14 and 15 are formed separately from the roller rotating shaft 20 and are fixedly attached to both ends of the roller rotating shaft 20 by fixing means (not shown).

  The roller rotating shaft 20 is formed of a resin material, and ABS resin, POM (polyacetal resin), or the like can be used as the resin material. On the outer periphery of the roller rotation shaft 20, spiral ribs (indicated by reference numerals R <b> 2 and R <b> 5 in FIG. 5B) that rotate along a rotation axis (a line parallel to the axial direction passing through the rotation center): (Referred to as “spiral ribs”) and auxiliary ribs (indicated by reference numerals R1, R3, and R6 in FIG. 5B) that connect adjacent spiral ribs and extend in the circumferential direction are integrated by resin molding. Is formed. Reference numerals R4 and R7 denote ribs (hereinafter referred to as “main ribs”) extending in parallel with the rotation axis direction.

  In the present embodiment, an angle formed by a plane perpendicular to the spiral rib and the axis of rotation of the roller rotation shaft 20 (a line parallel to the left-right direction in FIG. 5) (indicated by reference symbol α in FIG. 5B): (Referred to as “rib inclination angle”) is set to 45 °.

In the case of a screw, this rib inclination angle corresponds to an angle formed by a spiral winding of a thread and a plane perpendicular to the axis of the screw passing through one point, that is, a so-called lead angle. If there is, it becomes parallel to the rotation axis of the roller rotation shaft 20 like a rib indicated by reference numeral r2 in FIG.
In the present embodiment, the rib inclination angle is set to 45 °. However, the present invention is not limited to this, and it is needless to say that various optimum values can be selected depending on the use mode.

  FIG. 5 (A) shows the force applied to each rib in the embodiment where the rib inclination angle is 0 ° (the rib inclination angle of the rib r2 is 0 °), and FIG. 5 (B) shows the embodiment where the rib inclination angle is 45 °. The force applied to each rib in the example (the rib inclination angle of the ribs R2 and R5 is 45 °, that is, the spiral rib) is shown.

  In FIG. 5A, the rib r2 is a rib extending parallel to the rotation axis, and the rib r1 is a rib extending in a direction perpendicular to the rib r2 (extending along the circumferential direction). When a force f1 (torque applied from the motor) is applied to the rib r1, a force f2 is applied to the rib r2. The direction of the force f2 is a direction orthogonal to the direction in which the rib r1 extends. That is, since a longitudinal force is applied to the rib r1 that is strong against lateral compression, resistance to twisting (twisting rigidity) is reduced.

  On the other hand, in the embodiment of the present invention shown in FIG. 5B, when a force F1 (torque applied from the motor) is applied to the rib R1, a force V2 acts on the rib R2, thereby generating a force H2. To do. The force F2 is a resultant force of the force V2 and the force H2, and the direction thereof is the direction in which the helical rib R2 that is resistant to compression is compressed (the direction in which the rib extends), so that the torsional rigidity is improved.

  Further, a part of the force F2 acts on the auxiliary rib R3, and its vertical component applies a force V3 to the rib R5, thereby generating a force H3 on the rib R5. The force F3 is a resultant force of the force V3 and the force H3, and the direction thereof is the direction in which the helical rib R5 that is resistant to compression is compressed (the direction in which the rib extends), so that the torsional rigidity is also improved by the rib R5.

  Further, the force F3 also acts on the rib R6, and similarly, the force acts between the ribs, and the magnitude thereof is attenuated. That is, the auxiliary rib R3 bears a part of the force transmitted to the spiral rib R2 and fulfills the function of transmitting to the spiral rib R5, so that the torsional rigidity is improved.

  In addition, when this inventor performed the model analysis by the finite element method, axial volume (volume also including a rib) was made constant, and a rib angle was changed from 0 degree (FIG. 5 (A)) to 45 degrees (FIG. 5 ( It has been confirmed that the twist angle is remarkably reduced when changed to B)).

  As described above, since the roller rotating shaft 20 is integrally provided with the spiral rib turning around the rotation axis along the outer periphery, the torsional rigidity can be improved and the twisting amount (twisting angle) can be suppressed. In addition, since the auxiliary ribs connecting the spiral ribs and integrally extending along the circumferential direction are integrally provided, the torsional rigidity can be further improved and the amount of twisting (twisting angle) can be further suppressed. In this embodiment, since the rib inclination angle is 45 °, the torsional rigidity can be improved regardless of the rotation direction of the torque applied to the roller rotation shaft 20.

DESCRIPTION OF SYMBOLS 1 Inkjet printer, 2 Paper feed part, 3 Paper feed roller unit, 4 Scanner unit, 11 Paper cassette, 12 Separation slope, 13 Friction pad, 14, 15 Gear, 16 Tooth wheel train, 18 Feed roller, 19 Oscillating member , 20 roller rotation shaft, 22 reversing roller, 23 retard roller, 24 intermediate roller, 25 guide member, 30 on paper guide, 31 tension spring, 33, 34 frame, 36 carriage, 37 inkjet recording head, 40 transport drive roller, 41 Conveyance driven roller, 45 Before paper guidance, 45a-45b Rib, 46 Auxiliary roller, 47 Ejection drive roller, 48 Ejection driven roller, P Recording paper, R2, R5 Spiral rib, R1, R3, R6 Auxiliary rib, R4, R7 Main rib

Claims (4)

A rotating shaft that is rotated by a rotational torque applied from a power source,
A spiral rib that swirls along the axis of rotation is integrally provided on the outer periphery.
A rotating shaft characterized by that. The rotating shaft according to claim 1, which integrally includes auxiliary ribs extending along a circumferential direction that connect the adjacent spiral ribs.
A rotating shaft characterized by that. In the rotating shaft according to claim 1 or 2, an angle formed by the spiral rib and a surface perpendicular to the rotating shaft center line is 45 °.
A rotating shaft characterized by that. A feeding roller for feeding the recording medium by rotating in contact with the recording medium;
The rotating shaft according to any one of claims 1 to 3, wherein the feeding roller is attached, and torque of a motor that is a driving source of the feeding roller is transmitted to the feeding roller.
A recording apparatus comprising:

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