JP3938156B2 - Folding device - Google Patents

Description

  The present invention relates to a folding apparatus used as a post-processing apparatus such as an image forming apparatus.

As a folding device used as a post-processing device of an image forming apparatus, for example, as described in Patent Document 1, there is an apparatus that can perform a trifold that creases two places on a sheet. In such a folding apparatus, a three-fold process is performed by two folding processes.
JP 2003-54808 A

  In the folding device described in Patent Document 1, the folded sheet is introduced into the folding processing unit at the time of the second folding process. In this case, a pair of folding rollers in the folded state, that is, press contact Since the rear end of the folded sheet passes between the folding rollers, there is the following problem.

  The crease formed by the first fold process passes between the fold rollers that are in pressure contact with each other, so that the crease is applied again, and the second fold is displaced from the first fold. Collapses or has wrinkles.

  Since the folded paper is twice as thick, there is a problem of impacting the folding roller when the fold passes.

  An object of the present invention is to solve such a problem that occurs in multiple folding processing.

The object is achieved by the following invention.
1. In the folding device in which the intermediate portion of the paper is introduced between a pair of folding rollers that are pressed against each other and conveyed by the folding roller, and a plurality of folding portions are provided along the paper conveyance path.
At least one of the downstream folds of the fold is
A first conveying roller pair comprising an upstream first folding roller and a first pressure roller in pressure contact with the first folding roller;
The second conveying roller pair consisting of the second pressing roller which presses against the second folding roller and the second folding rollers of the downstream side, has,
The pair of folding rollers formed by the first folding roller and the second folding roller and the second conveying roller pair are:
In the folding process in which a sheet is fed between the pair of folding rollers to form a folded portion on the sheet, the sheet is pressed against the sheet,
After the folding step, before the folding portion of the sheet formed by the upstream folding portion located upstream from the at least one downstream folding portion passes between the folding roller pair and the second conveying roller pair. Folding device characterized in that it is spaced apart .

The invention of claim 1, a plurality of times of folding process the fold applied against the one the paper processing, or collapsed folds formed previously, problems such deviation or or wrinkles are generated are resolved, folding A high-quality multi-folding process in which the above is correctly formed is performed.

(1) Image Forming Apparatus FIG. 1 is an overall view of an image forming apparatus including an image forming apparatus main body A, an automatic document feeder DF, a post-processing apparatus B, and a large-capacity paper feeding apparatus LT.

  The illustrated image forming apparatus main body A includes an image reading unit (image input device) 1, an image processing unit 2, an image writing unit 3, an image forming unit 4, paper feed cassettes 5A, 5B, and 5C, a manual paper feed tray 5D, A first paper feed unit 6A, 6B, 6C, 6D, a second paper feed unit 6F, a fixing device 7, a paper discharge unit 8, and an automatic duplex copy paper feed unit (ADU) 8B are provided.

  An automatic document feeder DF is mounted on the upper part of the image forming apparatus main body A. A post-processing device B is connected to the paper discharge unit 8 side on the left side of the image forming apparatus main body A shown in the figure.

  The document placed on the document table of the automatic document feeder DF is conveyed in the direction of the arrow, the image on one or both sides of the document is read by the optical system of the image reading unit 1, and is read by the image sensor 1A.

  The analog signal photoelectrically converted by the image sensor 1A is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the image processing unit 2, and then sent to the image writing unit 3.

  In the image writing unit 3, output light from the semiconductor laser is irradiated onto the photosensitive drum 4 </ b> A of the image forming unit 4 to form a latent image. In the image forming unit 4, processes such as charging, exposure, development, transfer, separation, and cleaning are performed. An image is transferred by the transfer unit 4B to the paper S fed from the paper feed cassettes 5A to 5C, the manual paper feed tray 5D, and the large capacity paper feeder LT by the first paper feed units 6A to 6E. The sheet S carrying the image is fixed by the fixing device 7 and sent from the paper discharge unit 8 to the post-processing device B. Alternatively, the single-sided image-processed paper S sent to the automatic double-sided copy paper feeding unit 8B by the conveyance path switching plate 8A is again discharged from the paper discharge unit 8 after the double-sided image processing in the image forming unit 4.

(2) Post-Processing Device The post-processing device B includes a post-processing device carry-in unit 10, a post-processing device discharge unit 20, a paper adding unit (cover paper feeding unit) 30, a punching processing unit (punch processing unit, first processing unit). ) 40, a conveyance unit 50, and a folding processing unit (second processing unit) 60.

  FIG. 2 is an overall configuration diagram of the post-processing apparatus B according to the present invention.

(2-1) Post-Processing Device Carry-in Unit / Post-Processing Device Ejecting Unit The post-processing device carry-in unit 10 is fed with the paper S that has undergone image forming processing from the image forming apparatus main body A.

  The paper introduction position of the post-processing apparatus carry-in section 10 faces the paper discharge position of the paper discharge section 8 of the image forming apparatus main body A.

  The sheet S introduced into the entrance roller 11 is branched to either the post-processing apparatus discharge unit 20 or the punching processing unit 40 (branching unit) by the conveyance path switching unit G1.

  When the punching process and the folding process are not set, the conveyance path switching unit G1 blocks the conveyance path to the punching processing unit 40 and opens the conveyance path to the post-processing apparatus discharge unit 20.

  The sheet S passing through the first conveyance path p1 toward the post-processing device discharge unit 20 is sandwiched between the conveyance rollers 21 and 22 and advances straight, and is discharged from the post-processing device discharge unit 20 by the discharge roller 23 and can be moved up and down. Stacked on the main paper discharge tray 24. A maximum of 2000 sheets S can be stacked on the main paper discharge tray 24.

  The sheet S branched upward in the figure on the downstream side in the sheet conveyance direction of the conveyance roller 22 by the conveyance path switching means G2 passes through the conveyance roller 25 in the sixth conveyance path p6 and is discharged by the paper discharge roller 26, and is a post-processing device. The paper is stacked on a sub paper discharge tray (top tray) 27 as a post-processing apparatus discharge portion arranged at the upper part of B. On the sub paper discharge tray 27, paper on which an image is formed as a test, paper discharged after jam processing, and the like are stored.

(2-2) Paper adding unit 30
The cover sheet or the insert sheet S accommodated in the sheet feeding tray 31 of the sheet adding unit 30 is separated and fed by the sheet feeding means 32, and the conveyance rollers 33, 34, 35, and 36 in the fifth conveyance path p5. So as to join the conveyance path on the upstream side of the branching portion (merging portion).

  The sheet feeding trays 31 of the sheet adding unit 30 are arranged in two upper and lower stages, and each sheet feeding tray 31 can store a maximum of 500 cover sheets or insert sheets S.

  It is also possible to perform punching processing and folding processing on the paper S without loading the paper S in the paper adding unit 30 and performing image recording.

(2-3) Perforation processing unit 40
The sheet S branched by the transport path switching means G1 of the post-processing apparatus carry-in section 10 is sandwiched between transport rollers 41 disposed below the transport path switching means G1 and transported to the punching processing section (first processing section) 40. (Second transport path p2).

  An aligning means 42 is arranged in the transport path on the downstream side of the punching processing unit 40 and aligns the sheet width direction of the sheet S before the punching process.

  The punching device of the punching processing unit 40 includes a punch that is driven by a driving means (not shown) and a die that is fitted to the blade portion of the punch. The perforated paper S is sent to the lower conveyance unit 50 (punch function).

(2-4) Transport unit 50
The sheet S sent to the conveyance unit 50 is nipped by the conveyance rollers 51, 52, 53, and 54 and conveyed to the folding device 60. The conveyance rollers 51, 52, 53, and 54 include a driving roller that is connected to a driving source and a driven roller that is in pressure contact with the driving roller. Each driven roller is connected to a solenoid SOL and can be brought into contact with and separated from the drive roller.

  Of the small-sized paper S that has been punched, the paper S that is not subjected to folding processing passes through the third A transport path P3A branched by the transport path switching means G3, and is sandwiched by the transport rollers 600 and transported. . The large-size sheet S that has been punched is transported to the third B transport path P3B below the branching position of the transport path switching means G3 regardless of whether or not folding processing is necessary, and is transported by the transport rollers 53 and 54 to be folded. 60. Here, the third transport path P3A and the third B transport path P3B together constitute a third transport path.

  In addition, a conveyance path switching unit 55 is provided in the conveyance unit 50, and two small-size sheets S are accumulated and conveyed, whereby two sheets described later can be folded simultaneously.

(2-5) Folding device 60
The sheet S conveyed from the conveyance unit 50 to the folding device (second processing unit) 60 is nipped and conveyed by the registration rollers 601, and in the first folding unit 61, the second folding unit 62, and the third folding unit 63, Folding processing (folding function) of various modes such as outer middle fold, inner middle fold, Z fold, outer trifold, inner trifold, inner fourfold (hereinafter also referred to as Kannon fold) and double parallel fold, which will be described later, is applied. Then, it returns to the first transport path p1 via the fourth transport path p4.

  FIG. 3 is a cross-sectional view of the folding device 60.

  The first folding unit 61 includes a folding roller 611 and a pressure roller 613 that is in pressure contact with the folding roller 611, and a downstream folding roller 612 and a pressure roller 614 that is in pressure contact with the folding roller 612. The guide member 615 guides the sheet S to the nip between the pair of rollers and the folding rollers 611 and 612. The folding rollers 611 and 621 are driven and rotated by the motor M1 to convey and fold the paper S. The guide member 615 includes a roller that approaches and separates from the nip between the folding rollers, similarly to the guide member 721 described later.

  The folding device 60 holds a plurality of transport paths m, n, q, r, u, v, w, x, and a sheet S connecting the first folding unit 61, the second folding unit 62, and the third folding unit 63. A plurality of transport rollers 602, 6O3, 604, 605, 606, 607, 608, and 609 are disposed.

  The second folding part 62 and the third folding part 63 have substantially the same configuration as the first folding part 61, the first folding part 61 is at the bottom, the second folding part 62 is in the middle, and the third folding part 63. Are arranged at the top. When transporting from the first folding part 61 to the third folding part 63, the switching is directly guided by the transport switching means G4. The folding rollers 621 and 622 of the second folding unit 62 are driven by the motor M2 to rotate. The sheet S is conveyed and folded, and the folding rollers 631 and 632 of the third folding unit 63 are driven and rotated by the motor M3 to convey and fold the sheet S. The sheet S is supplied from below by the registration rollers 601 and, as will be described later in the process of being conveyed upward, the conveyance paths m to x and the first to third folding portions 61 to 62 are appropriately selected to perform various folding processes. Is done.

  The guide members 615, 633, and 721 have the same structure, and the guide member 721 will be described later.

(3) Folding Processing Next, various folding processing modes that can be executed using the three folding portions 61, 62, and 63 will be described.

  In the folding device 60, two-sided outer and inner-folding processes, three-sided opening Z-folding process, outer three-folding process, inner three-folding process, four-sided open folding process and double parallel folding process 7 The seed is viable. When the folding processing function is set, the sheet S after fixing is fed halfway to the automatic double-sided copy paper feeding unit 8B, and then reversed and carried out from the image forming apparatus main body A. The image is taken out with the image surface t facing down. Further, in the folding process of the paper S on which the double-sided image is formed, the image surface t is a surface that carries the front surface image.

(3-1) Outer / Folding Processing Outer / inner folding processing of the sheet S on the outer side of the sheet image surface is performed in the first folding unit 61.

  4A is a front view showing the processing path of the sheet S during the outer and middle folding process, FIGS. 4B to 4D are schematic diagrams showing the outer and middle folding process steps of the sheet S, and FIG. FIG. 4 is a perspective view of a folded sheet S.

  Hereinafter, the middle folding process step on the outer side of the sheet image surface will be described.

  (A) The sheet S formed and discharged by the image forming apparatus main body A with the image surface t facing down (face-down) is, as shown in FIG. As shown in FIG. 4A, the paper passes through the conveyance unit 50, is sandwiched by registration rollers 601 with the image surface t facing down, and is introduced into the folding device 60.

  The leading end of the sheet S conveyed to the first folding unit 61 passes through the nipping position between the folding roller 611 and the folding pressure contact roller 613 that are driven to rotate, and is nipped and conveyed by the folding roller 612 and the folding pressure roller 614 that are driven to rotate. And go straight on the conveyance path m. After the passage of the leading edge of the sheet is detected by the sensor PS1 (see FIG. 3), the driving of the folding rollers 611 and 612 is stopped by the control means CR (shown in FIG. 17) after a predetermined time has elapsed, and the sheet S is brought to a predetermined position. Stopped. The sheet stop position is an intermediate position between the folding rollers 611 and 612 near the center of the sheet S in the transport direction (see FIG. 4B).

  (B) When the reverse rotation driving of the folding roller 612 and the folding pressure contact roller 614 is started, the guide member 615 is actuated by the pressure contact position of the folding rollers 611 and 612 at one half position in the front end direction of the sheet S and is pressed and pressurized. Then, a folded fold a is formed (see FIGS. 4C and 4D).

  (C) The sheet S on which the folded fold line a is formed is sandwiched and discharged by the driven folding rollers 611 and 612, passes through the conveyance paths n and q with the fold line a as the head, and the second folding section Proceed to 62.

  (D) The sheet S in which the fold line a is formed and the half-folding process is completed is sandwiched by the driving conveyance rollers 603 and 607 and is discharged through the conveyance path r, and the first conveyance path starts from the fold line a. Proceed to p1.

(3-2) Inner / Folding Process The inner / folding process on the inner side of the sheet image surface of the sheet S is performed in the third folding unit 63.

  FIG. 5A is a front view showing the processing path of the sheet S during the inner / folding process, FIGS. 5B to 5E are schematic views showing the inner / folding process of the sheet S, and FIG. FIG. 4 is a perspective view of a folded sheet S.

  The sheet S introduced into the folding device 60 passes through the first folding unit 61 without being processed, and is sent to the third folding unit 63 through the conveyance paths n and v. In the third folding unit 63, the sheet S that has been subjected to the middle folding process by the folding rollers 631 and 632 with the image surface t set inward passes through the conveyance path r with the fold line a at the top, and is discharged to the first conveyance path p1. The

(3-3) Z-folding process In the Z-folding process on the paper S, the first folding part 61 performs a Z-folding first folding process, and the third folding part 63 performs a Z-folding second folding process. .

  6A is a front view showing a processing path of the paper S during the Z-folding process, and FIGS. 6B to 6G show a Z-folding process step by the first folding part 61 and the third folding part 63. FIG. It is a schematic diagram.

  The leading edge of the sheet S sandwiched between the registration rollers 601 and conveyed to the first folding unit 61 passes through a position where the folding roller 611 and the folding pressure contact roller 613 that are driven to rotate are in contact with the folding roller 612 that is driven to rotate. It is nipped by the roller 614 and conveyed. After the passage of the leading end of the sheet is detected by the sensor PS1, after a predetermined time has elapsed, the driving of the folding rollers 611 and 612 is stopped by the control means CR, and the sheet S stops at a predetermined position. This sheet stop position is a position where the leading edge of the sheet S has advanced by a quarter of the total length L in the sheet conveyance direction from the position where the folding rollers 611 and 612 are opposed (see FIG. 6B).

  By pressing the folding roller 612 against the folding roller 611 and driving the reverse rotation start of the folding roller 612 and the folding pressure contact roller 614, a quarter position in the front end direction of the sheet S is brought to the pressure contact position N of the folding rollers 611 and 612. The guide member 615 is pushed in and pressurized to form a first fold b of Z-fold (see FIG. 6C).

  The sheet S on which the first fold line b of the Z fold is formed is sandwiched and discharged by the folding rollers 611 and 612 that are driven to rotate, and proceeds to the third fold portion 63 with the first fold line b as the head (see FIG. 6 (d)).

  After the first fold b of the sheet S conveyed to the third folding unit 63 passes between the driving and rotating folding rollers 631 and 632 and the passage of the leading edge of the sheet is detected by the sensor PS3, the control is performed after a predetermined time has elapsed. The driving of the pair of folding rollers is stopped by means CR (shown in FIG. 17), and the sheet S stops at a predetermined position. In this paper stop position, the distance between the rear end portion of the paper S and the opposing position of the pair of folding rollers is a half of the total length L of the paper S (see FIG. 6E).

  In the same manner as the first folding unit 61, the center of the sheet S in the conveyance direction is pushed by the guide member 633 into the pressure contact position of the folding rollers 631, 632 and pressed by the pressing of the pair of folding rollers and the start of reverse rotation. The second crease c is formed (see FIG. 6F). At this time, the leading edge of the sheet S reaches the pressure contact position of the folding rollers 631 and 632 first, and then the curved portion serving as the second fold c reaches the pressure contact position. The guide member 633 is composed of a roller that approaches and separates from the nip between the folding rollers, like the guide member 721 described later.

  The sheet S in which the second fold c is formed and the Z-folding process is completed is sandwiched and ejected by the driving and rotating folding rollers 631 and 632 and the transport roller 606, and the transport path r starts from the second fold c. And is discharged to the first transport path p1 (see FIG. 6G).

  FIG. 6H is a perspective view of the sheet S that has been Z-folded. b is a first fold of the sheet S that has been subjected to Z-folding, c is a second fold, and t is an image surface. The Z-folded paper S has a shape suitable for file loading.

(3-4) Outer Tri-Fold Process In the outer tri-fold process for the paper S, the first fold part 61 performs the first fold process, and the second fold part 62 performs the second fold process.

  FIG. 7A is a front view showing the processing path of the paper S during the outer tri-fold process, and FIGS. 7B to 7G are outer tri-fold process steps by the first fold part 61 and the second fold part 62. It is a schematic diagram which shows.

  In the first folding unit 61, after the sensor PS2 detects passage of the conveyed paper S through the leading end and counts a predetermined pulse, the control means CR (shown in FIG. 17) stops the paper S at a predetermined position.

  After the leading edge of the sheet S stops at a position corresponding to two-thirds of the total sheet length L from the position where the pair of folding rollers is opposed, the first folding process is performed by the folding rollers 611 and 612, and the first fold line d is formed on the sheet S. Is formed (see FIGS. 7B to 7D).

  In the second folding section 62, the first fold d of the sheet S stops at a position that is one third of the total length L of the sheet from the position facing the folding rollers 621 and 622, and is then pushed by the guide member 721 and the folding roller 621. A second folding process is performed in step 622, and a second fold e is formed on the sheet S (see FIGS. 7E to 7G).

  The sheet S on which the second fold e is formed and the outer tri-folding process is completed is sandwiched between the folding rollers 621 and 622 and the transport rollers 604 and 605 of the second folding portion 62 that is driven to rotate, and the second fold e is formed. It is transported at the head, passes through the third folding part 63, is sandwiched and ejected by the transport rollers 608 and 609, passes through the transport path r with the second fold c as the head, and is discharged to the first transport path p1. (See FIG. 7A).

  FIG. 7H is a perspective view of the paper S that has been subjected to outer tri-fold processing into a Z-shape. d indicates the first fold of the sheet S that has been subjected to outer fold processing, e indicates the second fold, and t indicates the image surface.

(3-5) Inner Tri-Folding Process In the inner tri-folding process on the paper S, the first folding process is performed in the first folding part 61 and the second folding process is performed in the second folding part 62.

  Since the inner tri-fold process has the same sheet conveyance path during the outer tri-fold process, a front view showing the process path of the sheet S is omitted.

  FIGS. 8A to 8F are schematic views showing an inner tri-fold process step by the first fold part 61 and the second fold part 62.

  At the time of the inner fold processing, the stop position of the paper S in the first fold portion 61 and the second fold portion 62 is different.

  In the first folding unit 61, after the leading end of the sheet S stops at a position that is one third of the total length L of the sheet from the position where the folding rollers 611 and 612 are opposed, the guide member 615 is placed between the folding rollers 611 and 612. The first folding process is performed, and a first fold f is formed on the paper S (see FIGS. 8A to 8C).

  In the second folding section 62, after the first fold d of the sheet S stops at a position that is one third of the total length L of the sheet from the position where the folding rollers 621 and 622 are opposed, the guide member 721 is interposed between the folding rollers 621 and 622. , The second folding process is performed, and a second fold g is formed on the paper S (see FIGS. 8D to 8F).

  FIG. 8G is a perspective view of the sheet S that has been subjected to the inner folding process. f is the first fold of the sheet S that has been subjected to the inner folding process, g is the second fold, and t is the image plane.

(3-6) Double Parallel Folding Process In the double parallel folding process on the paper S, the first folding part 61 performs the first folding process, and the second folding part 62 performs the second folding process.

  In the double parallel folding process, the paper conveyance path during the outer tri-folding process is the same, so the front view showing the processing path of the paper S is omitted.

  FIGS. 9A to 9F are schematic diagrams illustrating a double parallel folding process performed by the first folding unit 61 and the second folding unit 62. FIG.

  In the double parallel folding process, the paper conveyance path during the outer trifold process and the inner trifold process is the same, but the stop position of the paper S is different.

  In the first folding unit 61, the leading end of the sheet S stops at a position that is a half of the total length L of the sheet from the position where the folding rollers 611 and 612 face each other, and is then pushed between the folding rollers 611 and 612 by the guide member 615. Then, the first folding process is performed, and the first fold line h is formed on the sheet S (see FIGS. 9A to 9C).

  In the second folding section 62, the first fold h of the sheet S stops at a position that is a quarter of the total length L of the sheet from the position facing the folding rollers 621 and 622, and then between the folding rollers 621 and 622. The second folding process is performed, and the inner second fold line i and the outer third fold line j are simultaneously formed on the sheet S (see FIGS. 9D to 9F).

  FIG. 9G is a perspective view of the paper S that has been subjected to the double parallel folding process. h is a first fold of the sheet S that has been subjected to double-parallel folding processing, i is a second fold, j is a third fold, and t is an image plane.

(3-7) Kannon folding process In the Kannon folding process on the paper S, the first folding unit 61 performs the first folding process, the second folding unit 62 performs the second folding process, and the third folding unit 63. A third folding process is performed at.

  FIG. 10A is a front view showing the processing path of the paper S during the kannon folding process, and FIGS. 10B to 10G are the first folding part 61, the second folding part 62, and the third folding part 63. It is a schematic diagram which shows a Kannon folding process process.

  In the first folding unit 61, the leading end of the sheet S stops at a position that is a quarter of the total length L of the sheet from the position facing the folding rollers 611 and 612, and is then pushed by the guide member 615 between the folding rollers 611 and 612. Then, the first folding process is performed, and the first fold pk is formed on the paper S (see FIGS. 10B to 10D).

  The sheet S on which the first fold line pk is formed is such that the interval between the rear end portion of the sheet S and the opposing position of the folding rollers 621 and 622 is a quarter of the total length L of the sheet. After stopping, the sheet is pushed between the folding rollers 621 and 622 by the guide member 633, the second folding process is performed, and the second fold pm is formed on the sheet S (see FIGS. 10E and 10F). .

  The sheet S on which the first fold line pk and the second fold line pm are formed is the third fold part 63, after the central part in the conveyance direction of the sheet S stops at the position opposite to the fold rollers 631, 632, and then the fold roller 631. , 632, the third folding process is performed, and a third fold n is formed on the sheet S (see FIGS. 10G and 10H).

  The sheet S for which the folding-in folding process has been completed is sandwiched and ejected from the third folding unit 63 by the transport rollers 606 and 607, and discharged to the first transport path p1 with the third fold n as the head (FIG. 10 ( a)).

  FIG. 10 (i) is a perspective view of the paper S that has been subjected to the double folding process. pk is the first fold of the paper S, pm is the second fold, n is the third fold, and t is the image plane.

(4) Second folding part 62
In the (2-5) folding device 60 and (3) folding process, the schematic configuration and the folding function of the folding device 60 have been described. Hereinafter, the second folding unit 62 will be described in detail. Note that the sheet S travels upward along the transport path q in FIG. 11 in the process of being introduced into the second folding unit 62, and in the folding process, after traveling down the transport path q, the sheet S travels along the transport path u to the upper left. Drive to. That is, since the sheet S is switched back in the conveyance path q, the upstream and downstream relationship is reversed between the introduction process and the folding process.

  In this specification, in order to avoid confusion, the upstream in the introduction process to the folding part is referred to as upstream in all processes, and the downstream in the introduction process is referred to as downstream in all processes.

Explained second folding unit with reference to FIG. 11 to 15. 11 is a front sectional view of the second folding part 62 in the introduction process, FIG. 12 is a side view of the folding rollers 621 and 622, FIG. 13 is a diagram showing a drive system of the folding rollers 621 and 622, and FIG. 14 is a folding process. It is front sectional drawing of the 2nd folding part 62 in a. FIG. 15 is a front sectional view showing a process of discharging the paper from the second folding part 62 .

  As shown in FIG. 11, the guide plates 80 and 81 form a transport path r, and the guide plate 82 and the lower part of the guide plate 84 form a transport path q, and the guide plate 83 and the central portion of the guide plate 84. And the guide plate 85 form a transport path v, and the folded upper portion of the guide plate 84 and the guide plate 85 form a transport path u (see FIG. 3 for the transport path).

  The second folding part 62 is disposed between the transport path q and the transport path r.

  As shown in FIG. 11, the folding roller 621 constituting the pair of folding rollers of the second folding section 62 is supported by the shaft 621X and rotates, and the pressure roller 621A as the first pressure roller is spring-loaded to the folding roller 621. )). The shaft 621X is not displaced.

  As shown in FIG. 12, the folding roller 621 supported by the shaft that is not displaced is fixed to the shaft 621X, but the cam 623 as the first displacement means supported by the shaft 621X is supported via the bearing BA. It can rotate independently of the cage folding roller 621. The folding roller 621 is rotated by the motor M2 (shown in FIG. 3) to carry and fold, but the cam 623 as the first displacing means is rotated by the motor (described later), as will be described later. Then, the folding plate 622 is displaced by rotating the swinging plate 70. Before the paper S is introduced, the folding rollers 621 and 622 are held apart from each other by the cam 623.

  A folding roller pair is constituted by the folding roller 621, and the folding roller 622 as a second folding roller supported by a displaceable shaft is supported by the swing plate 70 supported by the shaft 71. A swing lever 72 is rotatably supported on the shaft 722. Further, it is urged clockwise by a spring SP1. A roller 721 as a guide member is provided at the tip of the swing lever 72. A wire 625 is connected to the free end of the swing lever 72, and the wire 625 is wound around a rotating shaft 6251 driven by a motor (described later). Thus, the spring SP1 is held at a position away from the nip between the folding rollers 621 and 622 against the elasticity of the spring SP1, but in the folding process, as shown in FIG. 14, the nip between the folding rollers 621 and 622 approaches. Set to position. Such displacement of the roller 721 is performed by the motor and the spring SP1 that rotate the shaft 6251.

  The guide plates 80 and 81 are guide members that guide the leading edge of the paper S to be folded (the leading edge in the introduction process). The second folding part 62 feeds the paper S that has been folded in the first folding part 61. When further folding processing is performed, the folding portion SA of the paper S formed in the first folding portion 61 is guided.

  The conveyance path r formed by the guide plates 80 and 81 is preferably a straight line that is substantially perpendicular to the straight line connecting the shaft of the folding roller 622 and the pressure roller 622A as the second pressure roller.

  By forming the conveyance path r in such a substantially straight line, when the folding portion SA of the paper S enters the nip between the folding roller 622 and the pressure roller 622A in the folding process, it is folded back from the main body of the paper S. The traveling distance to the part becomes equal, the crease formed by the first fold part is maintained as it is, and a beautiful crease is made at the correct position.

  If the conveyance path r is bent, that is, if the guide plates 80 and 81 are bent, there is a difference between the travel distance of the main body portion of the paper S and the travel distance of the folded portion, and this difference causes the first folding. In some cases, the crease attached at the part is broken, the crease is shifted, or wrinkles are generated.

FIG. 13 shows a drive system for the folding rollers 621 and 622, FIG. 13 (a) shows the drive system in the introduction process, and FIG. 13 (b) shows the drive system in the folding process.
An integral gear GA1 coaxial with the folding roller 621 is connected to a motor M2 (shown in FIG. 3). The gear GA2 is a gear that is coaxial and integral with the folding roller 622, and GA3 is a clutch gear.

  As shown in FIG. 13A, in the introduction process, the folding roller 621 and the folding roller 622 are separated from each other, and the gears GA1 and GA2 are connected via the clutch gear GA3. Accordingly, the folding rollers 621 and 622 rotate counterclockwise, which is the same direction. By this rotation, the sheet is conveyed upward.

  As shown in FIG. 13B, in the folding step, the clutch gear GA3 is disengaged from the drive system, and the power transmission from the gear GA1 to the gear GA2 is cut off. Since the folding roller 622 is in pressure contact with the folding roller 621, the folding roller 622 is driven by the frictional force by the folding roller 621 through the sheet. Therefore, the folding roller 621 rotates counterclockwise, and the folding roller 622 rotates clockwise.

  The displacement of the folding roller 622 shown in FIG. That is, the cam 623 is rotated by the motor (not shown) through the gears GA4 and GA5, the cam follower 624 made of a disk is displaced following the cam 623, and the swing plate 70 is rotated to displace the folding roller 622. Let

  A mechanism for displacing the folding roller 622, such as the cam 623, the cam follower 624, and the swing member 70, is provided at both shaft ends of the folding rollers 621 and 622.

  Next, the folding action in the second folding part 62 will be described.

The process of introducing the paper S into the second folding part, performing the folding process, and transporting the paper S from the second folding part 62 includes:
a. An introduction process for introducing the paper S into the transport paths q and r;
b. A pair of folding rollers that includes a folding roller 621 serving as a first folding roller and a folding roller 622 serving as a second folding roller that conveys the first half of the sheet S in the reverse direction and the latter half in the forward direction. A folding step of pushing into the nip between,
c. A paper transporting process for carrying out the paper S after the folding process;
It consists of.

  In the introducing step, the pair of folding rollers are separated from each other, and the folding roller 621 and the pressure roller 621A as the first pressure roller are in pressure contact to form the first conveying roller pair, and the folding roller 622 and the second pressure roller are The second pressure roller 622A is in pressure contact to form a second transport roller pair.

  FIG. 11 shows a state in the introducing step of introducing the paper into the second folding part 62, and the paper S is introduced with the folding part SA formed at the leading part. In that case, it guides to the conveyance path q by the conveyance path switching means G4.

  The folding rollers 621 and 622 are rotated counterclockwise by a drive system that is separated by the cam 623 and the clutch gear GA3 is interposed, and forms a pair of conveying rollers with the pressure rollers 621A and 622A. Is conveyed to the upper right along the conveyance path q.

  When the upstream quarter portion of the sheet S reaches the middle of the folding rollers 621 and 622, the process shifts from the introduction process to the folding process, and the folding roller 622 is pressed against the folding roller 621 by the action of the cams 623 and 624. Thus, a pair of rollers in pressure contact with each other is formed, and the clutch gear GA3 is detached from the drive system as shown in FIG.

  As shown in FIG. 14, simultaneously with the displacement of the folding roller 622, the swing lever 72 rotates in the clockwise direction, and the roller 721 is displaced to approach the nip between the folding rollers 621 and 622. Due to the displacement of the folding roller 622 and the reversal of the rotation direction of the folding roller 622, the paper S that can be bent is actuated by the roller 721 by the elastic force of the spring SP1, and guided in the nip direction, with the folded portion SB at the head. It proceeds to the nip between the folding rollers 621 and 622.

  The folding roller 622 in pressure contact with the folding roller 621 rotates following the folding roller 621, and the sheet S is press-fitted between the folding rollers 621 and 622 by the rotation of the folding rollers 621 and 622 and folded.

When the folding of the sheet S is completed and the folded sheet S reaches the position of the conveying roller 604 as a conveying unit that conveys the folded sheet from the second folding unit 62, the operation of the second folding unit 62 Is temporarily stopped. Next, before starting the conveyance of the sheet S toward the conveyance path u, the cam 623 is rotated to separate the folding roller 622 from the folding roller 621 as shown in FIG. The contact of 621 and 622 is cut off. As shown in FIG. 14, the folding of the sheet S is completed and separated by the cam 623. Such in conjunction with the operating clutch gear GA3 as shown in FIG. 13 (b) rotating the folding rollers 622 engage only the gear GA2 folding roller 622 in the counterclockwise direction, but fold from folded sheet S Since the rollers 622 are separated, the conveyance is not affected. FIG. 15 shows a state in which the folding roller 622 is separated from the folding roller 621 in this way.

  In the state of FIG. 15, the folding roller 622 is separated from the folding roller 621, and the pressure roller 622 </ b> A is separated from the folding roller 622.

  The pressure contact / separation mechanism of the pressure roller 622A with respect to the folding roller 622 is as follows.

The pressure roller 622A is supported by one end of the swing lever 73, and the other end of the swing lever 73 is in contact with a cam 74 as second displacement means. The pressure roller 622A is in pressure contact with the folding roller 622 by the bias of the compression spring SP3, but is separated from the folding roller 622 by the rotation of the cam 74. The cam 74 is rotated by a motor drive as will be described later.
FIG. 15 shows a state where the pressure roller 622A is separated by the motor.

  Next, the conveyance of the folded sheet S is started by the conveyance roller 604. In this way, the sheet S on which the first folding unit SA is formed is separated between the folding roller 622 and the pressure roller 622A and the separated folding. It passes between the roller 621 and the folding roller 622.

  Therefore, deformation of the first folding part SA, generation of wrinkles and the like are prevented, and the motor M2 that drives the folding roller 621 is also prevented from receiving an impact.

  FIG. 16 is a block diagram of a control system of the second folding unit 62 shown in FIGS. 11 to 16, and FIG. 17 shows an operation sequence of the motors M2 and M4 to M6.

  M4 is a motor for driving the cam 623, M5 is a motor for driving the shaft 6251, and M6 is a motor for driving the cam 74.

  The control means CR controls the operation described above based on the paper leading edge detection signal of the sensor PS2 provided in the paper introducing portion of the second folding portion. A stepping motor is used as the motor M2 for driving the conveyance rollers including the folding roller 621. The control means CR reversely conveys the folding rollers 621 from the introduction step of introducing the paper into the conveyance paths q and r. The folding process for introducing the sheet between the sheets 622, the displacement control of the roller 721 executed in the folding process and the conveyance of the sheet are temporarily stopped, the folding roller 622 is separated from the folding roller 621, and the pressure roller 622A is folded. The start and end of various steps such as the step of separating from 622 are determined based on the counted number by counting the number of driving pulses for driving the motor M2 from the reference based on the detection of the PS2. The motors M4 to M6 are started and stopped.

  As shown in FIG. 17, the motor M2 is started at the detection time T0 of the paper S by the sensor PS2 of FIG.

  An introduction step is performed in which the sheet S is conveyed by driving the motor M2, and the leading end of the sheet S is introduced into the conveyance path r.

  At the time T1 when the motor M2 is driven with a predetermined number of pulses, the motor M2 is stopped, and in conjunction with this stop, the motors M4 and M5 are started to drive the cams 623 and 6251, and the folding roller 622 is moved to the folding roller. The roller 721 is brought close to the nip between the folding roller 621 and the folding roller 622 while being brought into pressure contact with 621. Based on the stop signal of the motor M4, the motor M2 is operated at T2 to drive the folding roller 621, and the folding process is executed.

  At the time T3 when the motor M2 is driven with a predetermined number of pulses, the motor M2 is stopped, and based on the stop signal, the motor M4 and the motor M6 are operated to separate the folding roller 622 from the folding roller 621 and to press the pressure roller. The sheet is conveyed by separating 622A from the folding roller 622.

  The size of the paper to be folded and the number of pulses corresponding to the folding processing mode are stored in the memory of the control means CR. The control means CR controls the start / stop of the motors M4 to M6 according to the paper size and the folding processing mode. To perform the above-mentioned steps.

1 is an overall view of an image forming apparatus. It is a general view of a post-processing apparatus. It is sectional drawing of the folding apparatus which concerns on embodiment of this invention. FIG. 6 is a front view showing a paper processing path during outer and inner folding processing, a schematic diagram showing outer and middle folding processing steps of the paper, and a perspective view of the folded paper. FIG. 6 is a front view showing a paper processing path during an inner / inner folding process, a schematic diagram showing an inner / inner folding process step, and a perspective view of the folded paper. FIG. 5 is a front view showing a processing path of the paper S during the Z-folding process, a schematic diagram showing a Z-folding process, and a perspective view of the paper that has been Z-folded. FIG. 6 is a front view showing a paper processing path during an outer tri-fold process, a schematic diagram showing an outer tri-fold process, and a perspective view of a sheet that has been subjected to an outer tri-fold process. It is a schematic diagram which shows an inner trifold process, and is a perspective view of the paper by which the inner trifold process was carried out. FIG. 5 is a schematic diagram showing a double parallel folding process, and a perspective view of a sheet subjected to double parallel folding. It is a front view showing a paper processing path at the time of folding door folding processing, a schematic diagram showing a folding door folding process, and a perspective view of a paper sheet that has been subjected to folding door folding. It is front sectional drawing of the 2nd folding part in an introduction process. It is a side view of a folding roller pair. It is a figure which shows the drive system of a folding roller. It is sectional drawing of the 2nd folding part in a folding process. It is sectional drawing of the 2nd folding part at the time of completion | finish of a folding process. It is a block diagram of the control system of a 2nd folding part. It is a figure which shows the action | operation sequence of a 2nd folding part.

Explanation of symbols

A Image forming apparatus main body B Post-processing device 61 1st folding unit 62 2nd folding unit 63 3rd folding unit 611, 612, 621, 622, 631, 632 Folding rollers 613, 614, 621A, 622A Pressing rollers 623, 74 Cam 721 roller

Claims (1)

In the folding device in which the intermediate portion of the paper is introduced between a pair of folding rollers that are pressed against each other and conveyed by the folding roller, and a plurality of folding portions are provided along the paper conveyance path.
At least one of the downstream folds of the fold is
A first conveying roller pair comprising an upstream first folding roller and a first pressure roller in pressure contact with the first folding roller;
The second conveying roller pair consisting of the second pressing roller which presses against the second folding roller and the second folding rollers of the downstream side, has,
The pair of folding rollers formed by the first folding roller and the second folding roller and the second conveying roller pair are:
In the folding process in which a sheet is fed between the pair of folding rollers to form a folded portion on the sheet, the sheet is pressed against the sheet,
After the folding step, before the folding portion of the sheet formed by the upstream folding portion located upstream from the at least one downstream folding portion passes between the folding roller pair and the second conveying roller pair. Folding device characterized in that it is spaced apart .

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