JP6231849B2 - Paper feeder - Google Patents

Description

  The present invention relates to a sheet feeding device that feeds sheets stacked on a sheet feeding table that can be raised and lowered by a plurality of sheet feeding rollers.

  2. Description of the Related Art Generally, image forming apparatuses such as a printing apparatus that prints images and characters on paper and a copying machine that copies images and characters on paper are provided with a paper feeding device that feeds paper.

  When a sheet loaded on a sheet feeding table is fed by a sheet feeding roller using this type of sheet feeding device, the sheet is fed if the outer size of the sheet is A3 size (297 mm × 420 mm) or less. A sheet feeding roller is usually installed at the center of the sheet width direction perpendicular to the sheet feeding direction, but when the sheet size is A2 size (420 mm × 594 mm) or more, the sheet feeding roller transports the sheet. In order to ensure this, there is a paper feeding device in which a plurality of paper feeding rollers are installed along the paper width direction (see, for example, Patent Document 1).

  In the paper feeding device described in Patent Document 1, a paper feed table on which paper is stacked is provided so as to be lifted and lowered by a lift driving device along the outer surface of the device main body.

  Further, in the vicinity of the paper feed position above the paper feed table, a single rotation shaft that is rotated by a drive source is provided along the paper width direction. The one rotating shaft is provided with one paper feed roller and auxiliary rollers (paper feed rollers) disposed on both sides of the paper feed roller.

  Further, a plurality of paper feed rollers are provided with a facing member, and each roller is in sliding contact with each of the feeding members.

  Then, when the uppermost sheet loaded on the sheet feeding table comes into contact with the plurality of sheet feeding rollers as the sheet feeding table rises upward from the lower standby position, the plurality of sheet feeding rollers are rotated. As a result, the sheet is fed from between each sheet feed roller and each sheet member.

JP 2010-105774 A

  By the way, according to the paper feeding device described in Patent Document 1, a plurality of paper feeding rollers are integrally mounted on one rotating shaft in order to feed paper of A2 size or larger. However, there is no disclosure of a paper feed position detection mechanism for detecting that the uppermost sheet stacked on the paper feed stage has reached the paper feed position.

  At this time, when any foreign object enters between the uppermost sheet and one of the plurality of paper feed rollers while the paper feed base is raised, the paper feed base is raised. As a result, there is a problem that foreign matter is caught between the uppermost sheet and the paper feed roller and damaged.

  In order to solve the above-described problems, it is assumed that a plurality of paper feed rollers are swingably supported on a single rotation shaft via a plurality of rotation transmission mechanisms and are opposed to the plurality of paper feed rollers. If a plurality of paper feed position detection mechanisms are provided, it is considered that the uppermost paper loaded on the paper feed tray can be fed appropriately, but there is a problem that the cost of the paper feed device is increased.

  Therefore, even if some foreign matter is sandwiched between the uppermost sheet and the paper feed roller while the paper feed stand is raised, the foreign matter is not damaged, and the low-cost paper feeding device The purpose is to provide.

The present invention has been made in view of the above-mentioned problems, and the invention according to claim 1 is provided so as to be movable up and down via a lifting motor, and is equipped with a sheet feeding table on which sheets are stacked,
One rotating shaft provided along the width direction of the paper and driven to rotate by a roller driving motor;
The uppermost sheet among the sheets stacked on the sheet feeding table, supported by a plurality of swingable arms mounted on the one rotation axis at intervals, and rotated through a rotation transmission mechanism. A plurality of paper feed rollers that feed
The arm is disposed so as to face one of the plurality of sheet feeding rollers, and the uppermost sheet comes into contact with the one sheet feeding roller as the sheet feeding table is raised. A paper feed position detecting unit that detects that the uppermost sheet has reached the paper feed position by the roller position being displaced upward via
The amount of displacement of the sheet feed roller that does not face the sheet feed position detection unit among the plurality of sheet feed rollers is the amount of displacement of the one sheet feed roller that faces the sheet feed position detection unit. The sheet feeding device is characterized in that it is set larger than the above.

  According to the paper feeding device of claim 1, a plurality of swingable plurality of swingable units attached at intervals on one rotating shaft installed along the width direction of the paper loaded on the up and down paper feeding table. Each of the plurality of paper feed rollers is supported by the arm, and one of the plurality of paper feed rollers faces the paper feed position detection unit. By making the amount of displacement upward of the paper feed roller not facing the paper larger than the amount of displacement of one paper feed roller facing the paper feed position detector, the uppermost paper or paper feed roller It is possible to ensure the safety of the paper feeding device without damaging the paper and foreign matter. Furthermore, since only one paper feed position detection unit is provided, a low cost paper feed device can be provided.

1 is a configuration diagram illustrating a sheet feeding device according to the present invention and an image forming apparatus to which the sheet feeding device is applied. In the paper feeding device according to the present invention, the one rolling roller fixed to one rotating shaft and the one paper feeding roller supported swingably on the one rotating shaft via one arm are enlarged. It is sectional drawing shown. In the sheet feeding device according to the present invention, a perspective view showing a plurality of separating rollers fixed to one rotating shaft and a plurality of sheet feeding rollers supported by the one rotating shaft through a plurality of arms in a swingable manner. FIG. (A)-(f) is a timing chart of each structural member in the paper feeder which concerns on this invention. (A), (b) schematically shows the state of the sheet feeding roller disposed in the center and the sheet feeding roller disposed on the left side or the right side when the sheet feeding base is raised in the sheet feeding device according to the present invention. It is a figure.

  Hereinafter, an embodiment of a paper feeding device according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 shows a sheet feeding apparatus according to the present invention and an image forming apparatus to which the sheet feeding apparatus is applied. FIG. 2 shows a sheet feeding device according to the present invention, one sheeting roller fixed to one rotating shaft, and one sheet feeding roller supported on the one rotating shaft through one arm so as to be swingable. And are enlarged. Further, FIG. 3 shows a plurality of sheet feeding rollers fixed to one rotating shaft and a plurality of sheet feeding rollers supported on the one rotating shaft through a plurality of arms so as to be swingable in the sheet feeding device according to the present invention. It shows.

  As shown in FIG. 1, a paper feeding device 20 according to the present invention is applied to an image forming apparatus 10 such as a printing device that prints an image or a character on a paper P, or a copier that copies an image or a character on the paper P. It is configured to be possible.

  The sheet feeding device 20 is installed on the left side of the casing 11 that forms the outer shape of the image forming apparatus 10.

  Further, in the housing 11 of the image forming apparatus 10, a registration roller pair 12 that adjusts the conveyance timing of the paper P while correcting the skew of the paper P fed by the paper feeding device 20, and an image on the paper P. Are formed in this order from the upstream side to the downstream side in the conveyance direction of the paper P.

  Further, a control unit 15 that controls the paper feeding device 20, the registration roller pair 12, the image forming unit 13, and the paper discharge unit 14 is installed in the housing 11 of the image forming apparatus 10.

  Here, the paper feeding device 20 according to the present invention will be described in detail. A paper feeding base 21 on which a plurality of papers P are stacked includes a paper feeding base raising / lowering motor 22 using a geared motor and a rack pinion (not shown). It is provided so that it can be moved up and down along one outer surface 11a of the housing 11 by a mechanism.

  At this time, a plurality of one type of paper P having the same outer size of the paper P is stacked on the paper feed tray 21, but here, for example, a plurality of paper P of A2 size (420 mm × 594 mm) is stacked. ing.

  In addition, in the vicinity of the paper feed position set above the paper feed table 21, a single rotation shaft 24 rotated by a roller driving motor 23 using a geared motor has a paper width perpendicular to the conveyance direction of the paper P. It is provided long along the direction. One rotary shaft 24 described above is pivotally supported by a pair of bearings 25 (shown only in FIG. 3) at both ends.

  Further, on one rotating shaft 24, a plurality of separating rollers 26 corresponding to the A2 size (420 mm × 594 mm) paper P are fixed with a predetermined interval K (FIG. 3), and a plurality of separating rollers 26 are fixed. A plurality of separating plates 27 are provided below the separating rollers 26 to which the paper P fed by the respective separating rollers 26 comes into sliding contact.

  In addition, on one rotating shaft 24, one end sides of a plurality of arms 28 are swingably supported in pairs with a plurality of separating rollers 26, respectively.

  Further, on the other end side of the plurality of arms 28, one sheet feeding roller 30 is rotatably supported by a pair of the plurality of separating rollers 26 via a shaft 29.

  Accordingly, the plurality of the separating rollers 26 and the plurality of the sheet feeding rollers 30 can secure the conveyance force to the A2 size sheet P.

  At this time, the plurality of separation rollers 26 and the plurality of separation plates 27 are located in the housing 11 of the image forming apparatus 10. On the other hand, the plurality of paper feed rollers 30 are positioned on the outer side of one outer surface 11a of the housing 11 and are the uppermost paper among the plurality of papers P stacked on the paper feed table 21 that can be raised and lowered. It is free to contact and separate from Pu.

  Here, since the plurality of separating rollers 26 and the plurality of sheet feeding rollers 30 are configured in the same manner, one set of one separating roller 26 and one sheet feeding roller 30 will be described in detail with reference to FIG. Describe.

  As shown in an enlarged view in FIG. 2, a stepped shaft 31 is press-fitted toward the rolling roller 26 and the sheet feeding roller 30 at an intermediate portion between one end and the other end of an arm 28 that is swingably supported on one rotating shaft 24. It is fixed by.

  Further, the first gear 32 disposed between the one roller 26 fixed to one rotating shaft 24 and the arm 28 is also fixed to one rotating shaft 24. The first gear 32 meshes with the second gear 33 that is pivotally attached to the stepped shaft 31 described above. Further, the second gear 33 meshes with a third gear 34 that is fixed together with the paper feed roller 30 to a shaft 29 that is pivotally supported on the other end side of the arm 28.

  At this time, the first to third gears 32 to 34 are a kind of a rotation transmission mechanism connected to one rotating shaft 24 for rotationally driving the paper feed roller 30, and the first to third gears 32 to 34 are connected. Instead, timing belt drive is also possible.

  Accordingly, one set of one roller 26 and one paper feed roller 30 uses a roller driving motor 23 that rotates one rotating shaft 24 as the same drive source, and the first to third gears 32 to 32 are used. By rotating both in the counterclockwise direction shown in FIG. 1, the uppermost paper Pu can be fed.

  Further, as shown in FIG. 3, one sheeting roller 26 and one sheet feeding roller 30 are combined to form a plurality of groups corresponding to the A2 size sheet P, for example, three groups of sheeting roller 26 and sheet feeding roller 30. Are arranged along one rotation axis 24.

  At this time, among the three sets, the centering roller 26 and the paper feeding roller 30 are arranged at the central portion in the width direction of the A2 size paper P, and each has a predetermined interval around the center set. Another set of the separating roller 26 and the sheet feeding roller 30 are arranged on both the left and right sides separated by K, respectively.

  Further, the three sets of the separating roller 26 and the paper feeding roller 30 are respectively covered with a case 35 having an opening at the bottom. Each group of the rolling rollers 26 is in sliding contact with a rolling plate 27 installed below this group. On the other hand, each set of paper feed rollers 30 protrudes from the opening 35a of each case 35 toward the uppermost paper Pu below.

  At this time, each pair of cases 35 inserts a shaft 29 supporting the paper feed roller 30 between the outer surfaces facing each other to prevent the paper feed roller 30 from coming off from both outer surfaces. The arm 28 can be swung integrally with the attached arm 28.

  Further, a bracket 36 is bent in an L shape at the front surface 36a and the lower surface 36b at an upper portion on the downstream side in the paper transport direction with respect to each roller 26, and is provided long along the paper width direction. Yes. Therefore, the bracket 36 is substantially parallel to the single rotation shaft 24.

  In addition, bent pieces 35c are formed so as to protrude from the top surface 35b of each case 35 toward the downstream side in the paper transport direction. The bent piece 35c of each case 35 passes through the lower surface 36b of the bracket 36 and is freely contactable with and separated from the concave notch 36c formed on the lower surface 36b. Each bent piece 35c contacts the concave notch 36c. The stand-by posture of each paper feed roller 30 that hangs down in the direction of gravity via each arm 28 (FIGS. 1 and 2) when it comes into contact is regulated.

  In addition, a plurality of cut pieces 36d to 36f are formed on the upper portion of the front surface 36a of the bracket 36 so as to cut substantially at right angles toward the upstream side in the paper transport direction.

  Since the paper feed position detection unit 37 is attached to the central cut piece 36e among the plurality of cut pieces 36d to 36f using a micro switch (or an optical sensor), the paper feed position detection unit ( The micro switch 37) is disposed above the paper feed roller 30 so as to face the paper feed roller 30 disposed in the center via the case 35.

  The uppermost paper Pu comes into contact with the central paper feed roller 30 as the paper feed table 21 is raised, so that the roller position of the paper feed roller 30 is higher than the uppermost paper Pu via the arm 28. When the switch abutting portion 35b1 projecting on the top surface 35b of the central case 35 that swings integrally with the arm 28 abuts against the microswitch 37 when displaced toward the top, the uppermost paper Pu is supplied. It is possible to detect that the paper position has been reached.

  On the other hand, a micro switch (paper feed position detection unit) is not provided facing the paper feed rollers 30 arranged on the left and right.

  Therefore, since the micro switch (paper feed position detecting unit) 37 for detecting that the uppermost paper Pu loaded on the paper feed tray 21 has reached the paper feed position is provided at one place, the paper feeder 20 is provided. It can be provided at low cost.

  Accordingly, the left and right paper feed rollers 30 not facing the microswitch (paper feed position detection unit) have a swing stroke that swings upward from the uppermost paper Pu via the arm 28. Further, the stroke is set to be larger than the swing stroke through the arm 28 of the central paper feed roller 30 facing the micro switch (paper feed position detection unit) 37.

  In other words, the displacement amount of the left and right paper feed rollers 30 that do not face the paper feed position detection unit among the plurality of paper feed rollers 30 is the center paper feed roller that faces the paper feed position detection unit 37. That is, it is set larger than the amount of displacement of 30.

  Accordingly, the left and right cut pieces 36d and 36f among the plurality of cut pieces 36d to 36f formed on the bracket 36 corresponding to the left and right paper feed rollers 30 in which the displacement amount of the paper feed roller 30 is set large. Each of the tension springs 38 having a weak urging force is hooked between the spring hooking portions 35b2 provided on the top surfaces 35b of the left and right cases 35, and the left and right paper feeds hang downward by the tension springs 38. The gravity of the roller 30 is reduced.

  Further, among the plurality of overcut pieces 36d to 36f formed in the bracket 36, the left and right overcut pieces 36d and 36f are formed with stopper pieces 36d1 and 36f1 with which the top surfaces 35b of the left and right cases 35 abut. The operation of these stopper pieces 36d1 and 36f1 will be described later in the operation.

  As described above, the micro switch (paper feed position detection unit) 37 is opposed to the paper feed roller 30 disposed in the center. However, the present invention is not limited to this. It suffices if the sheet feeding roller 30 is opposed.

  Here, the operation of the sheet feeding device 20 according to the present invention configured as described above will be described with reference to FIGS.

  4A to 4F show timing charts of the respective components in the sheet feeding device according to the present invention. FIG. 5 shows the operation of the paper feeding device according to the present invention when the paper feeding base is raised, (a) shows the state where the paper feeding roller arranged at the center has reached the paper feeding position, (B) is a diagram showing a state in which foreign matter has entered below the paper feed rollers arranged on the left or right side.

  As shown in FIGS. 4A to 4E and FIG. 5A, when the sheet feeding table raising / lowering motor 22 is started, the sheet feeding table 21 on which a plurality of sheets P are loaded is located outside the casing 11. It rises along the side surface 11a.

  When the paper feed roller 30 arranged at the center contacts the uppermost paper Pu among the plurality of papers P stacked on the paper feed table 21, the paper feed roller 30 is connected to one rotating shaft 24 via the arm 28. As a result, the roller is displaced slightly from the standby position.

  At this time, the case 35 covering the sheet feeding roller 30 disposed in the center also swings slightly upward together with the sheet feeding roller 30. As a result, the switch abutting portion 35b1 formed on the top surface 35b of the case 35 abuts on the microswitch (paper feed position detecting portion) 37 attached to the cutting piece 36e at the substantially center of the bracket 36, and the microswitch 37 is thereby brought into contact. Since it is turned on, the control unit 15 determines that the uppermost paper Pu loaded on the paper feed tray 21 has reached the paper feed position.

  Here, since the control unit 15 stops the sheet feed table raising / lowering motor 22 and starts the roller driving motor 23 to rotate one rotating shaft 24, the roller 15 and the sheet feeding roller disposed in the center are provided. 30 rotates counterclockwise.

  At this time, if the periphery of the uppermost paper Pu stacked on the paper feed tray 21 is in a normal state, the separating roller 26 and the paper feed roller 30 arranged on the left and right also rotate counterclockwise.

  Therefore, if the periphery of the uppermost sheet Pu is in a normal state, the uppermost sheet Pu is separated one by one when the uppermost sheet Pu passes through each of the separating plates 27 by the three sets of the separating roller 26 and the sheet feeding roller 30. Paper is fed downstream.

  When the paper feeding operation is continued, the loading amount of the plurality of papers P stacked on the paper feeding table 21 decreases, so that the control unit 15 turns on the paper feeding table raising / lowering motor 22 every time the predetermined number of sheets decreases. / OFF control is performed so that the uppermost paper Pu reaches the paper feed position.

  On the other hand, as shown in FIGS. 4 (f) and 5, while the paper feed table 21 is raised, the topmost paper Pu loaded on the paper feed table 21 and a micro switch (paper feed position detection unit). ) And a paper feed roller 30 arranged on the left or right side that is not opposed to the left side or the right side, and some foreign matter I enters the uppermost sheet Pu with the upper side of the paper Pu as the paper feed table 21 is raised. When sandwiched between the paper feed rollers 30, the left or right paper feed roller 30 swings significantly upward about the one rotation shaft 24 via the arm 28 and reaches the retreat position. The foreign matter I can be removed during the retreat.

  While the sheet feed table 21 is moving up, the uppermost layer loaded on the sheet feed table 21 by the micro switch 37 due to the displacement of the roller position of the sheet feed roller 30 arranged in the center before the load is applied to the foreign matter I. When it is detected that the paper Pu has reached the paper feed position, the paper feed table 21 is stopped, so that the safety of the paper feed device 20 can be ensured.

  At this time, the case 35 covering the left or right sheet feeding roller 30 also swings significantly upward, and the top surface 35b of the case 35 becomes the left or right cutting piece 36d or 36f of the bracket 36. The retreat range of the left or right sheet feeding roller 30 is allowed until it comes into contact with the formed stopper piece 36d1 or 36f1.

  As described above, the paper feed roller is attached to the plurality of swingable arms 28 attached to the one rotary shaft 24 disposed along the width direction of the paper P corresponding to the paper P of A2 size or more with a space therebetween. 30, and when one of the plurality of sheet feeding rollers 30 is opposed to the sheet feeding position detection unit 37, the sheet feeding position detection unit among the plurality of sheet feeding rollers 30. For example, the amount of displacement of the sheet feeding roller 30 disposed on the left side or the right side that is not opposed to the sheet is set larger than the amount of displacement of, for example, the center sheet feeding roller 30 facing the sheet feeding position detection unit 37. Yes.

  As a result, some foreign matter I enters between the uppermost sheet Pu stacked on the sheet feeding table 21 and the left or right sheet feeding roller 30 while the sheet feeding table 21 is moving up. In addition, since the foreign matter I can be retreated by swinging the paper feed roller 30 upwardly from the uppermost paper Pu via the arm 28, the uppermost paper Pu, the paper feed roller 30, The safety of the paper feeding device 20 can be ensured without damaging the foreign matter I. Furthermore, since only one paper feed position detector 37 is provided, the low cost paper feeder 20 can be provided.

DESCRIPTION OF SYMBOLS 10 ... Image forming apparatus, 11 ... Housing | casing, 11a ... One outer side surface,
20: Paper feeding device,
21... Paper feed table, 22... Motor for raising and lowering the paper feed table, 23...
24 ... one rotating shaft, 26 ... whispering roller, 27 ... whispering plate, 28 ... arm,
29 ... Shaft, 30 ... Feed roller, 31 ... Stepped shaft,
32 ... 1st gear, 33 ... 2nd gear, 34 ... 3rd gear,
35 ... Case, 36 ... Bracket, 37 ... Paper feed position detector (microswitch),
I: Foreign matter, P: Paper, Pu: Top paper.

Claims (2)

A paper feed base provided with a paper stack, which can be raised and lowered via a lift motor;
One rotating shaft provided along the width direction of the paper and driven to rotate by a roller driving motor;
The uppermost sheet among the sheets loaded on the sheet feeding table, supported by a plurality of swingable arms mounted on the one rotation shaft at intervals, and rotated through a rotation transmission mechanism. A plurality of paper feed rollers that feed
The arm is disposed so as to face one of the plurality of sheet feeding rollers, and the uppermost sheet comes into contact with the one sheet feeding roller as the sheet feeding table is raised. A paper feed position detecting unit that detects that the uppermost sheet has reached the paper feed position by the roller position being displaced upward via
The amount of displacement of the sheet feed roller that does not face the sheet feed position detection unit among the plurality of sheet feed rollers is the amount of displacement of the one sheet feed roller that faces the sheet feed position detection unit. A paper feeding device characterized in that it is set larger than the above. Three paper feed rollers are provided in the paper width direction,
The paper feed position detection unit is installed facing the central paper feed roller, and the amount of displacement of the left and right paper feed rollers across the central paper feed roller is larger than the amount of displacement of the central paper feed roller. The sheet feeding device according to claim 1, wherein the sheet feeding device is set large.

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