JP2011246260A - Sheet folding apparatus and image formation system having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet folding apparatus capable of surely removing a sheet jammed in a sheet folding mechanism part by simple operation.SOLUTION: A guide member 42 is arranged for guiding a folding sheet along a peripheral surface of a second roll 49 between a third roll 50 and a fourth roll 64 by bringing a plurality of rolls into pressure contact in order of the second, the third and the fourth with a first roll 41b positioned in the center. The first roll is arranged in a first bracket member for rocking in the separating direction from the second and third rolls, and the fourth roll and the guide member are arranged in a second bracket member 46 for rocking in the separating direction from the first roll. The first bracket member and the second bracket member are interlocked so as to rock in the separating direction by an operation means arranged in one of them.

Description

  The present invention relates to a sheet folding apparatus that folds an image-formed sheet, and relates to an improvement of a sheet conveying mechanism that transfers a sheet to a folding mechanism section.

  In general, this type of sheet folding apparatus is widely known as an apparatus for folding and finishing a sheet on which an image has been formed by an image forming apparatus such as a printing machine, a printer apparatus, or a copying machine at a predetermined folding position. For example, Japanese Patent Application Laid-Open No. 2003-228620 proposes an apparatus that folds an image-formed sheet connected to a paper discharge port of an image forming apparatus for filing and transports the sheet to a subsequent binding processing apparatus.

  Thus, the sheet folding apparatus that folds the sheet in half or one-third and carries it out is configured as a post-processing apparatus of the image forming apparatus, or is built in the image forming apparatus or the binding processing apparatus. It is configured as a unit. Various folding specifications are known for filing depending on the purpose of use, such as 1/2 folding, outer 3 folding, and 1/3 letter folding.

  Therefore, a folding device (unit) that is connected to or built in an image forming apparatus, a binding device (finisher device, bookbinding device), or the like includes a folding processing mechanism and a conveyance mechanism that feeds and sets sheets. ing. For example, Patent Document 1 discloses a folding plate in which a pair of rollers for folding a sheet bundle is provided on a stacking guide for aligning sequentially fed sheets in a bundle shape, and the roller pair is disposed at a position facing the roller pair across a path. An apparatus for inserting a fold of a sheet bundle into a nip portion of a roller pair with a (folding blade) is disclosed.

  Similarly, in Patent Document 2 and Patent Document 3, a pair of roller pairs and a folding plate are arranged in a path for feeding a sheet, and the folding position of the sheet is inserted into the nip portion of the roller pair by the folding plate and folded. Is disclosed. Further, on the upstream side and the downstream side of the folding roll, the conveying means for feeding out the leading end and the trailing end of the sheet is constituted by a leading end stopper and a belt in Patent Document 2 and a roller in Patent Document 3, respectively. . A folding processing apparatus that folds a bundle of sheets by stacking sheets together is widely known in Patent Documents 1 to 3, for example.

  On the other hand, Patent Document 4 discloses an apparatus that folds sheets fed from an image forming apparatus one by one and carries them out to a downstream post-processing apparatus. In this document, a plurality of rollers are arranged in pressure contact with each other in the rotational direction of the roller disposed at the center, the sheet is primarily folded at the upstream roller nip portion, and the sheet is secondarily folded at the downstream roller nip portion. A folding roll mechanism for carrying out along a roller peripheral surface is disclosed.

  A folding mechanism that folds a sheet with a roller pair in this manner is widely known. However, when a sheet jam occurs at a folded portion, it is difficult to remove the sheet. For example, Patent Document 5 discloses a roller mechanism in which three rollers are pressed against each other to fold a sheet, and Patent Document 6 discloses a roller mechanism in which two rollers are pressed against each other. Both documents convey the sheet to the roller mechanism. There is disclosed a jam handling mechanism that removes a jam sheet sandwiched between rollers by opening a conveyance mechanism.

Japanese Patent Laying-Open No. 2008-247531 (FIG. 1) JP 2007-320665 A Japanese Patent Laying-Open No. 2008-7297 (FIG. 7) JP 2006-76776 A (FIG. 1) Japanese Patent Laid-Open No. 61-2638 (FIG. 4) JP-A-11-106112 (FIG. 4)

  As described above, for example, Patent Document 4 proposes a folding roll mechanism that folds sheets fed from the carry-in portion one by one and carries them out to the downstream side. This folding roll mechanism is basically composed of three rollers. The second roller and the third roller are arranged around the first roller located at the center, the sheet is primarily folded at the upstream nip portion, and then downstream. The sheet is secondarily folded at the side nip. It is also known that a pressure roller (increasing roller) is provided on the most downstream side of the first roller, and the sheet folded on the upstream side is subjected to strong pressure finishing (increasing folding).

  Thus, in the folding mechanism in which a plurality of rollers are radially pressed against the central roller and the sheet is diffracted a plurality of times, it is necessary to press each roller strongly. In other words, if the pressure contact portion of the roller is weakly engaged, there is a problem that the fold position of the sheet is distorted as well as the sheet cannot be reliably folded. For this reason, the rollers that are in pressure contact with each other are in an engagement state with little elastic deformation and strong pressure contact. Therefore, removal of the jam sheet generated at the pressure contact portion of the folding roll becomes a problem.

  On the other hand, as a method of removing a jammed sheet at the pressure contact portion of a pair of rollers that are in pressure contact with each other, Patent Documents 5 and 6 propose to remove the sheet sandwiched between the rollers by releasing the sheet conveying mechanism. .

  As described above, conventionally, when a sheet is jammed at the pressure contact portion of the pair of folding rollers, the transport mechanism in front of the sheet is opened, and the sheet is pulled out while being sandwiched between the rollers. For this reason, a thin sheet or a sheet gathered by jam may be partially damaged and remain in the apparatus. Further, the user may be injured when the sheet sandwiched between the rollers is pulled out in the apparatus.

  Therefore, the present inventor can release a plurality of press contact portions by retreating the roller located in the center in the folding roll mechanism in which a plurality of press contact rollers are arranged around the center roller, and at the same time reliably. It came to the idea that it is possible to return to the original engagement relationship.

An object of the present invention is to provide a sheet folding apparatus that can reliably remove a jammed sheet by a simple operation by a sheet folding mechanism for folding the sheet.
Furthermore, the present invention provides a sheet folding apparatus that is simple and safe in removing the jammed sheet by the sheet folding mechanism in an apparatus configuration in which a folded sheet storage is provided below the sheet folding mechanism. Is the issue.

In order to achieve the above object, the present invention presses a plurality of rolls in the order of the second, third, and fourth to the first roll located at the center, and the first roll is between the third roll and the fourth roll. A guide member for guiding the folded sheet along the peripheral surface is provided.
The first roll is provided on a first bracket member that swings away from the second and third rolls, and the fourth roll and the guide member are second brackets that swing away from the first roll. Provided on the member. The first bracket member and the second bracket member are interlocked so as to swing in the separating direction by operating means provided on one side.

More specifically, the folding processing path (33) for folding the sheet sent from the carry-in section (30), the primary folding pressure contact section (Np1), the secondary folding pressure welding section (Np2), and the additional folding pressure welding section. Folding roll means (41b, 49, 50, 64) for forming (Np3) and a paper discharge path (36) for guiding the sheet folded by the folding roll means to the carry-out section (31).
The folding roll means includes a roll (41b, 50, 64) press-contacted in the second, third, and fourth order in the rotation direction of the first roll (49) located at the center, and the third roll (50). And the fourth roll (64), the folded sheet is constituted by a guide member (42) for guiding the folded sheet along the peripheral surface of the first roll.

The first roll is provided on the first bracket member (45), and the first bracket member is supported on the apparatus frame so as to be swingable so that the first roll is separated from the second roll and the third roll.
The fourth roll and the guide member are provided on the second bracket member (46), and the second bracket member is swingable so that the fourth roll and the guide member are separated from the first roll. To do. And the 1st bracket member and the 2nd bracket member mutually interlock | cooperate so that the 1st roll, the 4th roll, and the guide member may be spaced apart by the operation means arrange | positioned in any one.

  In the present invention, the second, third, and fourth rolls are pressed against the first roll located at the center in this order, and the folded sheet is formed along the peripheral surface of the first roll between the third roll and the fourth roll. The first roll is provided on the first bracket member that swings in the direction away from the second and third rolls, and the fourth roll and the guide member are separated from the first roll. Provided on the second bracket member that swings at a distance. Since the first bracket member and the second bracket member are interlocked so as to swing in the separating direction by the operating means provided on one side, the following effects can be obtained.

  A roll mechanism that performs primary folding, secondary folding, and additional folding of the sheet is folded in the process of moving the sheet along the first roll by pressing the second, third, and fourth rolls against the first roll located at the center. Since the processing is performed, the folding roll mechanism can be made compact and compact.

  According to the present invention, the first fold pressure contact portion and the secondary fold pressure contact portion can be simultaneously released by separating the first roll located at the center from the second and third rolls. The sheet can be removed. At the same time, the fourth roll and the guide member that are in pressure contact with the first roll can be simultaneously retracted in the separation direction. Accordingly, since the additional folding pressure contact portion and the guide member therefor can be retracted in conjunction with the folding pressure contact portion, the jam processing is easy and simple.

  In addition, the first roll is attached to the first bracket member and the fourth roll and the guide member are attached to the second bracket member so as to be swingable in the separating direction. Since the two bracket members are interlocked so as to swing in the separating direction by the operating means provided on one side, a plurality of press contact portions can be simultaneously released with a simple structure and a simple operation.

  Further, according to the present invention, a folding sheet storage portion is provided below the folding roll mechanism, and the second folding member is oscillated within the space of the folding sheet storage portion. The member can be swung and retracted at a wide angle, and the jam sheet can be safely taken out in a relatively large work space.

1 is an explanatory diagram of an overall configuration of an image forming system including a sheet folding apparatus according to the present invention. The principal part expansion explanatory drawing of the post-processing apparatus in the system of FIG. FIG. 2 is an explanatory diagram of an overall configuration of a sheet folding device in the system of FIG. 1. Explanatory drawing which shows the layout structure of a folding roller of FIG. 3, and a secondary folding deflection | deviation means. (A) shows the structure explanatory drawing of a folding process part, (b) is an expansion explanatory drawing of the cam engaging part of a bracket member. The conceptual diagram which shows the press-contact / separation state of a folding roller means. Explanatory drawing of the cancellation | release state of a folding process part. (A) is a block diagram of an operation means, (b) is detailed explanatory drawing of a cover member. FIGS. 5A and 5B are explanatory diagrams showing the secondary folding deflecting unit of FIG. 4, in which FIG. 4A shows a retracted state, FIG. 4B shows a state where the driven roller is in the operating position, and FIG. It is explanatory drawing of the drive mechanism of the primary folding deflection | deviation means and secondary folding deflection | deviation means in the apparatus of FIG. 3, (a) is an explanatory view which shows the state of a standby position, (b) shows the state of an operation position. 4A and 4B are explanatory diagrams of an operation state of the apparatus of FIG. 3, in which FIG. 3A shows a state where a sheet is registered, and FIG. 3B shows a state where the sheet is transferred from a first path to a second path. 4A and 4B are explanatory diagrams of the operating state of the apparatus of FIG. 3, in which FIG. 3A shows a state in which the sheet folding position is inserted into the first nip portion, and FIG. 3B shows a state in which the primary folded sheet is conveyed to the second switchback path. Indicates. FIGS. 4A and 4B are explanatory diagrams of an operation state of the apparatus of FIG. 3, in which FIG. 3A illustrates an initial state in which a sheet is secondarily folded at a second nip portion, and FIG. Shows the state of unloading. It is explanatory drawing of the sheet folding specification in the sheet folding apparatus of this invention, (a) is a mode which folds a sheet | seat inside 3 at a 1/3 position, (b) is a sheet | seat folded outside 3 at a 1/3 position. (C) shows a mode in which the sheet is Z-folded at a 1/4 position, (d) shows an inner three-folded form with a margin, and (e) shows an outer three-folded with a margin. An aspect is shown. Explanatory drawing of the control structure in the system of FIG. The flowchart which shows the processing operation in the control structure of FIG.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments. FIG. 1 shows an image forming system provided with a sheet folding apparatus B according to the present invention. This system includes an image forming apparatus A and a post-processing apparatus C, and a sheet folding apparatus B is attached to the post-processing apparatus C as a unit.

The image forming apparatus A is configured as a printer, a copier, a printer, or the like that sequentially forms images on sheets. 1 is composed of an image forming unit 7, a document reading unit 20, and a feeder unit (document feeding device) 25 as a composite copying machine having a copying machine function and a printer function.
Further, the post-processing apparatus C is configured to perform post-processing such as folding processing, punching, stamping processing, and binding processing on the sheet on which the image is formed by the image forming apparatus A. A sheet folding device B for folding the image-formed sheet is integrally provided in the post-processing device C. Hereinafter, the sheet folding apparatus B, the image forming apparatus A, and the post-processing apparatus C will be described in this order.

[Sheet folding device]
The sheet folding apparatus B according to the present invention is built in the image forming apparatus A or the post-processing apparatus C, or is configured as an independent apparatus (stand-alone configuration). The illustrated one is arranged as an optional unit between the image forming apparatus A and the post-processing apparatus C.

The sheet folding device B is shown in FIG. 3 as a whole, but the apparatus housing 29 is provided with a carry-in port 30 and a carry-out port 31, and the carry-in port 30 is located at a position continuous with the main body discharge port 18 of the image forming apparatus A on the upstream side. The carry-out port 31 is arranged at a position continuous with the sheet receiving port 69 of the downstream post-processing apparatus C. In the present invention, the sheet folding apparatus B is not provided with an independent apparatus housing 29, but may be built in, for example, the casing of the post-processing apparatus C. In this case, the carry-in port 30 and the carry-out port 31 are required. do not do.
Therefore, hereinafter, the carry-in port 30 is synonymous with the carry-in unit, and the carry-out port 31 is synonymous with the carry-out unit.

  As shown in FIG. 3, the carry-in port 30 and the carry-out port 31 are disposed so as to cross the apparatus housing 29, and the illustrated carry-in port 30 and the carry-out port 31 are disposed at positions that are substantially opposed in the horizontal direction. Between the carry-in port 30 and the carry-out port 31, a first conveyance path 32 (sheet conveyance path; the same applies hereinafter) for carrying out the sheet from the carry-in port 30 to the carry-out port 31 without being folded, and the carry-in port 30. A second conveyance path 33 (folding path; the same applies hereinafter) for folding the sheet from the sheet and carrying it out to the carry-out port 31 is arranged. A “sheet conveying mechanism” that conveys the sheet in a predetermined direction (horizontal direction) is arranged in the first conveying path 32, and a “folding mechanism” that folds the sheet is arranged in the second conveying path 33. .

[Route configuration]
As shown in FIG. 3, a first transport path 32 is disposed between the carry-in port 30 and the carry-out port 31 in the apparatus housing 29. As shown in the figure, this path may be arranged in a horizontal direction as a straight path, or may be arranged in a vertical direction even if it is constituted by a curved path. As described above, the first conveyance path 32 guides the sheet from the carry-in entrance 30 to the carry-out exit 31 without folding the sheet.

The second conveyance path 33 is configured as a path for folding the sheet from the carry-in entrance 30. For this reason, the sheet is branched from the first conveyance path 32 to guide the sheet from the carry-in entrance 30 to the folding positions Np1 and Np2. At the same time, the second transport path 33 is arranged in a direction intersecting the first transport path 32 as shown in FIG. 3, and a first folding position Np1 and a second folding position Np2 are set in this path.
The second transport path 33 includes a first switchback path (first reverse path) 34 for guiding the leading edge of the sheet for primary folding to the first folding position Np1, and a folding for secondary folding of the folded sheet. A second switchback path (second reversal path) 35 that guides the leading end of the sheet to the second folding position Np2.

Thus, the second conveyance path 33 is arranged in a direction intersecting with the first conveyance path 32, the first switchback path 34 is in the upper area of the first conveyance path 32, and the sheet is downstream from the intersection in the lower area ( The second switchback path 35 transported in the second folding position (Np2 direction) is configured to be opposed vertically.
The first switchback path 34 and the second switchback path 35 are each configured by a curved path, and are formed in an approximately S-shaped curve as shown in FIG. In the second conveyance path (folding processing path) 33, a folding processing unit 48, which will be described later, is arranged at the first folding position Np1 and the second folding position Np2, and a folded sheet from the second folding position Np2 is sent to the carry-out port 31. A third transport path 36 that carries out the heads is provided continuously.

The first conveyance path 32 and the second conveyance path 33 are arranged so as to cross each other, but the first switchback path 34 that guides the sheet to the first folding position Np1 is below the first conveyance path 32. The second switchback path 35 for guiding the folded sheet to the downstream side may be disposed above the first conveyance path 32.
In the embodiment of FIG. 3, the first transport path 32 is disposed in the horizontal direction. However, when the first transport path 32 is disposed in the apparatus housing 29 in the vertical direction, the first switchback path 34 and the second switchback are disposed. It is also possible to dispose the path 35 opposite to the left and right areas of the first transport path 32.

  Further, in the embodiment of FIG. 3, the second switchback path 35 is configured to reverse the sheet feeding direction in order to guide the folded sheet to the second folding position Np2 in order to perform the secondary folding of the sheet. However, when the sheet is not folded secondarily, it is possible to use a straight path, and in this case, it is not necessary to provide the second switchback path described above.

  The second transport path 33 is provided with a third transport path 36 that guides the folded sheet to the carry-out port 31. The illustrated third conveyance path 36 is provided between the second folding position Np <b> 2 where the sheet is secondarily folded and the carry-out port 31. A paper discharge path 37 for guiding the folded sheet to the storage stacker 65 from a paper discharge outlet 51 different from the carry-out port 31 is disposed in the third transport path 36.

  Then, the path length (L1) of the first switchback path 34 for guiding the sheet from the first conveying path 32 to the first folding position (first nip portion) Np1, and the first folded sheet is folded second. The path length (L2) of the second switchback path 35 for guiding to the position (second nip portion) Np2 is configured such that path length L1> path length L2.

  Further, the path length L3 of the sheet discharge path 37 for guiding the folded sheet from the second folding position Np2 to the storage stacker 65 is configured to satisfy L3 <L2 <L1. This is because when the first folding position (first nip portion) Np1 is arranged in the vicinity of the first transport path 32, each path length becomes L3 <L2 <L1, resulting in a compact path configuration.

  Accordingly, the first switchback path 34 having a long path length is disposed in the upper area of the first transport path 32, and the second switchback path 35 and the paper discharge path 37 having a short path length are disposed in the lower area so as to face the first switchback path 34. Further, a storage stacker 65 is disposed below the second switchback path 35 and the paper discharge path 37. With such a layout configuration, the inner space of the device housing 29 is concentrated.

[Route switching means]
The next path switching means 63 is disposed at the intersection of the first transport path 32 and the second transport path (folding processing path) 33 described above. As described above, the second conveyance path 33 guides the sheet branched from the first conveyance path 32 and fed from the carry-in entrance 30 to the first and second folding positions Np1 and Np2. For this reason, route switching means 63 is arranged at the intersection of the first and second transport routes 32 and 33. As shown in FIG. 3, the base end portion is pivotally supported by an apparatus frame (the illustrated one is a support shaft 62x of the carry-out roller 62a) so as to be swingable.

  Then, the path switching means 63 guides the sheet sent to the first conveyance path 32 in the solid line attitude of FIG. 3 to the first switchback path 34 of the second conveyance path 33, and enters the first conveyance path 32 in the attitude of the broken line in FIG. The fed sheet is guided from the pair of carry-out rollers 62 to the carry-out port 31.

  A sheet guide 61 is provided at the intersection of the first conveyance path 32 and the second conveyance path 3 together with the path switching means 63 described above. The sheet guide 61 is arranged between the second roll 41b and the carry-out roller pair 62 in the first conveyance path 32, and guides the sheet sent from the carry-in roller pair 40 to the second conveyance path 33, and at the same time, the first switch. The reverse sheet from the back path 34 is guided to the first folding position Np1. Further, the sheet guide 61 guides the sheet sent to the first transport path 32 from the unloading roller pair 62 to the transport outlet 31 without guiding the sheet to the second transport path 33.

  For this reason, the sheet guide 61 is disposed at an intersection where the conveyance span is relatively long, and guides the sheet to the second conveyance path 33 side and the carry-out port 31 side in cooperation with the path switching means 63 described above. As shown in FIG. 3, the illustrated apparatus is constituted by a guide plate supported on an apparatus frame so as to be swingable by a support shaft 61x.

[Folding roller configuration]
The second roll 41b, the first roll 49, and the third roll 50 are arranged in the second transport path 33 so as to be in pressure contact with each other. A first nip portion (first folding position) Np1 is formed at the pressure contact between the second roll 41b and the first roll 49, and the sheet is applied to the pressure contact between the first roll 49 and the third roll 50. A second nip portion (second folding position) Np2 for secondary folding is formed.

The diameters of the first, second, and third rollers are such that the second roller diameter is 30 mm at the maximum, the first and third roller diameters are 20 mm, and the first roll 49 located at the center is the maximum diameter ( (For example, 1.5 times). This is because the front end of the folded portion is configured to be compact by arranging the second roll 41b and the third roll 50 on the outer periphery of the first roll 49 in a satellite shape.
That is, the first nip portion Np1 that is primarily folded by pressing the small-diameter second roll 41b upstream of the large-diameter first roll 49 and the small-diameter third roll 50 downstream thereof is second-folded. Two nip portions Np2 are formed.

  Further, the second roll 41b is disposed at a position where a part of the outer periphery faces the first transport path 32, and the pinch roller 41a is pressed against the roller peripheral surface. As a result, the sheet in the first conveyance path 32 is conveyed downstream by the second roll 41b and the pinch roller 41a, and it is not necessary to provide a special conveyance means and its drive mechanism in the first conveyance path 32.

[Configuration of folding deflection means]
As described above, the folding roller means composed of the three rolls (41b, 49, 50) has a primary folding deflection means 53 at the first nip portion Np1 and a secondary folding deflection means at the second nip portion Np2. 54 is arranged. The primary folding deflection means 53 and the secondary folding deflection means 54 are configured by a mechanism that inserts the fold position of the sheet sent to the second conveyance path 33 into the first nip portion Np1 and the second nip portion Np2.

  The illustrated apparatus has the function of “inserting the sheet folding position into the roller nip portion” and the function of “feeding the leading and trailing edges of the sheet into the nip portion” for the primary folding deflection means 53 and the secondary folding deflection means 54. Therefore, the primary and secondary folding deflecting means 53 and 54 include driven rollers 53a and 54a and curved guides 53b and 54b, and are configured to move from the retracted position outside the path to the operating position within the path. Then, the driven roller and the curved guide are moved from the retracted position to the operating position, and the fold position of the sheet is inserted into the nip portion.Then, the driven roller is pressed against the circumferential surface of the folding roller and rotated to move the front and rear ends of the sheet. Acts to feed into the nip.

[Configuration of primary folding deflection means]
The primary folding deflection means 53 includes a driven roller 53a, a curved guide 53b, and an elevating member 53c as shown in FIG. 4 for guiding the sheet fold to the first nip portion (pressure contact) Np1.

  As shown in FIG. 4, the first nip portion Np1 for first folding the sheet is composed of a second roll 41b and a first roll 49. The second roll 41b is arranged on the upstream side, and the first roll 49 is arranged on the downstream side. Yes. Therefore, the driven roller 53 a is disposed at a position in contact with the peripheral surface of the first roll 49. And the curved guide 53b is comprised by the curved surface along the surrounding surface of the 2nd roll 41b located in an upstream.

  The driven roller 53a and the curved guide 53b are supported by an elevating member 53c. The elevating member 53c is composed of a bracket member (frame member) having an appropriate shape, and the driven roller 53a is rotatably supported by the elevating member 53c, and at the same time, the curved guide 53b is fixed. The elevating member 53c is supported by a guide rail (not shown) provided in the apparatus frame, and the operating position (a broken line position in FIG. 4) where the driven roller 53a contacts the peripheral surface of the first roll 49 and the path of the second transport path 33. It is configured to move up and down between the standby position retracted outside (solid line position in FIG. 4). The elevating member 53c is connected to a shift motor MS, which will be described later, and moves the driven roller 53a and the curved guide 53b between the operating position and the standby position.

  The driven roller 53a is in pressure contact with the first roll 49 located on the downstream side, and the pressure contact is indicated by p2 in FIG. Therefore, when guiding the fold position of the sheet to the first nip portion Np1, the rear end side of the sheet is given a conveying force by the pressure contact p1, and is guided to the first nip portion Np1 along the peripheral surface of the second roll 41b. The Further, the front end side of the sheet is given a conveying force by the pressure contact p <b> 2 and is guided to the first nip portion Np <b> 1 along the peripheral surface of the first roll 49.

  At this time, the conveyance length Lx between the pressure contact p1 and the first nip portion Np1 and the conveyance length Ly between the pressure contact p2 and the first nip portion Np1 are set to Lx> Ly. The position of the driven roller 53a is set according to such a conveyance length relationship. And the above-mentioned curve guide 53b forms the curve-shaped curve guide surface along the surrounding surface of the 2nd roll 41b with large conveyance length.

In other words, conventionally, a blade member for guiding the sheet folds to the fold nips (Np1, Np2) is provided separately from the sheet steering means. It was the cause that occurred. In order to solve this problem, the illustrated apparatus sets the conveyance length Lx of the second roll 41b on the upstream side of the sheet toward the first nip portion Np1 and the conveyance length Ly of the first roll 49 on the downstream side to [Lx> Ly], and at the same time, the curved guide surface of the curved guide 53b is configured so that the sheet runs along the peripheral surface of the second roll 41b having a long conveying length, and the driven roller 53a and the curved guide 53b are simultaneously moved from the standby position. The position has been moved to the operating position.
With this configuration, the sheet fold can be accurately guided to the first nip portion Np1 without using any special folding blade means.

[Configuration of secondary folding deflection means]
Next, the secondary folding deflection means 54 will be described. As shown in FIG. 4, the secondary folding deflecting means 54 includes an elevating member 54c, a driven roller 54a attached thereto, and a curved guide 54b. The driven roller 54a is arranged at a position facing the peripheral surface of the third roll 50 located on the downstream side of the first roll 49, and the curved guide 54b is located at a position facing the peripheral surface of the first roll 49 located on the upstream side. Is arranged.

  At the same time, the driven roller 54a and the curved guide 54b are moved between the retracted position Wp retracted from the sheet transport path (hereinafter referred to as the sheet path Sp; see FIG. 4) by the elevating member 54c and the operating position Ap entered into the sheet path Sp. The position is configured to move.

  As shown in FIG. 4, the elevating member 54c is arranged to reciprocate at a predetermined stroke S along a guide rail (not shown) provided on the apparatus frame. A rack 54r is integrally formed with the elevating member 54c, and a pinion 54p that meshes with the rack is disposed on the apparatus frame side. The drive of the pinion 54p is transmitted to a shift motor MS described later. Therefore, the drive is transmitted so that the pinion 54p reciprocates in the rack 54r with a predetermined stroke S by forward and reverse rotation of the shift motor MS.

  On the other hand, the curved guide 54b is swingably supported by the apparatus frame. The illustrated one is integrally formed with a bracket 54d loosely fitted to the rotation shaft 41x of the second roll 41b, and the guide surface of the curved guide 54b is disposed at a position facing the peripheral surface of the first roll 49. The curved guide 54b is engaged so as to move between a retracted position retracted from the seat path Sp and an operating position entering the path in conjunction with the reciprocating movement of the elevating member 54c.

  Similar to the primary folding deflection means 53, the secondary folding deflection means 54 described above applies a conveying force to the sheet at the first nip portion Np1 of the first roll 49 located on the upstream side. From this point, the second nip portion Np2 The conveyance length Ly between the pressure contact p3 between the driven roller 54a and the third roll 50 located on the downstream side and the second nip portion Np2 is set to [Lx> Ly]. (See FIG. 4).

  The curved guide surface of the curved guide member 54b is formed in a shape that allows the sheet to run along the peripheral surface of the first roll 49 having a long conveying length. The secondary folding deflection means 54 and the primary folding deflection means 53 move reciprocally so that when one is in the operating position, the other is in the standby position. This is because the elevating member 53c and the elevating member 54c are raised and lowered by the same driving means (described later).

[Operation of secondary folding deflection means]
Therefore, the operation of the secondary folding deflection means 54 will be described with reference to the operation state diagrams of FIGS. 9 (a) to 9 (c). The sheet whose sheet leading edge is folded at the first folding position Np1 is sent to the second switchback path 34 in the state shown in FIG. At this time, the driven roller 54a and the curved guide 54b are located at the retracted position retracted from the sheet path Sp. As shown in the drawing, the retracted positions of the driven roller 54a and the curved guide 54b are set outside the path away from the sheet path Sp. In the state of FIG. 9A, the driven roller 54a is positioned at the retracted position, and the curved guide 54b is also positioned at the retracted position. This retracted position is set to a position retracted from the sheet path Sp to the outside of the path.

Next, after an expected time (for example, a detection signal of the leading edge detection sensor S2 described later) that the sheet leading edge reaches a predetermined position on the second switchback path 34, the lifting member 54c is moved from the retracted position (top dead center) to the operating position (bottom position). Move to the dead center) side. Then, the driven roller 54a is brought into contact with the circumferential surface of the third roller 50 and presses the folded front end of the sheet in the state of FIG.
At this time, the above-described elevating member 54c and the engaging piece 54j of the bending guide 54b are arranged in a positional relationship where the bending guide 54b is positioned on the retracted position side where it does not enter the sheet path Sp. In the state of FIG. 9B, the driven roller 54a is positioned at the operating position, and the curved guide 54b is positioned at a position close to the sheet path Sp. The position of the curved guide 54b is set to a position away from the sheet path Sp.

  In this way, the curved guide 54b is configured so that the driven roller 54a enters the sheet path Sp after the leading end of the sheet presses against the peripheral surface of the third roller 50 (the state shown in FIG. 9B). The position of the crease is not displaced by the curved guide 54b.

  Then, after the driven roller 54a comes into contact with the circumferential surface of the third roller 50, the leading end of the sheet folded by the rotation of the roller 50 is reversed and conveyed (switchback conveyance) toward the second folding position Np2. At this time, if the curved guide 54b is stopped, the leading end of the sheet may abut against this and the leading end may be bent. On the other hand, after the curved guide 54b enters the sheet path Sp and moves toward the operating position, the bending position of the sheet is inserted into the second nip portion Np2 without causing the sheet leading edge to bend.

This state is shown in FIG. 9 (c). The elevating member 54c further overruns after the driven roller 54a contacts the peripheral surface of the third roller 50 with a predetermined stroke, and the curved guide 54b is moved to the second nip portion Np2. Move to an operating position close to At this time, the follower roller 54a is compressed by the adjuster spring 54e to allow the overrun operation of the elevating member 54c.
In the state of FIG. 9C, the bending guide 54b and the driven roller 54a are both positioned at the operating position. Then, the curved guide 54b enters the sheet path Sp after the driven roller 54a is positioned at the operating position, and moves the leading end of the sheet reversely conveyed by the driven roller 54a to the second nip portion Np2 by moving to the operating position. insert.

  As described above, the elevating member 54c, the driven roller 54a, and the bending guide 54b are moved from the retracted position to the operating position after the roller 54a moves to the operating position and presses the leading edge of the folded sheet against the circumferential surface of the folding roller. Then, the curved guide 54b is moved to the operating position Ap.

[Sheet transport mechanism]
The sheet transport mechanism of the first transport path 32 and the second transport path 33 will be described with reference to FIG. In the first transport path 32, a pair of carry-in rollers 40 is arranged at the carry-in entrance (carry-in section) 30, and a pair of carry-out rollers 62 is arranged at the carry-out exit (carry-out section) 31, and a registration roller is arranged between these rollers. The illustrated registration roller includes an outer periphery of a second roll 41b described later and a pinch roller 41a in pressure contact therewith.
Accordingly, a carry-in roller pair 40, a carry-out roller pair 62, and a registration roller (second roll) 41b are arranged in the first conveyance path 32.

  The carry-in roller pair 40 includes a pair of rollers 40a and 40b, and a conveyance motor Mf (not shown) described later is connected to one of the rollers 40b. Similarly, the carry-out roller pair 62 includes a pair of rollers 62a and 62b, and a conveyance motor Mf is connected to one of the rollers 62b. The pinch roller 41a is disposed so as to be driven and rotated by the second roll 41b, and the second roll 41b is also connected to the transport motor Mf.

A second roll 41b, a first roll 49, and a third roll 50 are arranged in pressure contact with each other in the second conveyance path (folding processing path) 33, and a pair of paper discharge rollers 67 are arranged in the paper discharge path 37. Has been. As shown in FIG. 3, no sheet transport mechanism is arranged in the second transport path 33 (the first switchback path 34 and the second switchback path 35).
Then, a sheet is carried into the first switchback path 34 by a pair of carry-in rollers 40 and a registration roller (second roll) 41b disposed in the first conveyance path 32 in the second conveyance path 33, and the first and second rolls 49 and 41b convey the sheet to the downstream side.

  The illustrated apparatus is characterized in that the sheet conveying mechanism disposed in the first and second conveying paths 32 and 33 is simplified, and the apparatus is reduced in size, silence, and power consumption is reduced. For this reason, a part of the outer periphery of the folding roller (second roll 41 b) disposed in the second conveyance path 33 is transferred to the first conveyance path 32 between the carry-in roller pair 40 and the carry-out roller pair 62. Arranged to face.

  A pinch roller 41 a is arranged on the outer periphery of the second roll 41 b, and the sheet sent from the carry-in roller pair 40 is sent to the first switchback path 34. As a result, it is not necessary to arrange a special transport roller in the first transport path 32, and the transport mechanism is simplified.

  At the same time, when the sheet is folded, the second roll 41b is rotated to convey the pair of carry-in rollers 40 and the sheet from the carry-in roller pair 40 to the first switchback path 34 by the second roll 41b. In the mode and the mode in which the sheet is conveyed from the carry-in entrance 30 to the carry-out exit 31 without being folded, the second roll 41b is stopped and the carry-in roller pair 40 and the carry-out roller pair 62 feed the sheet from the carry-in entrance 30 to the carry-out exit 31. Transport. This reduces power consumption and achieves quiet operation.

[Folder configuration]
As described above, the folding processing section 48 includes the first, second, third, and fourth rolls 49, 41b, 50, and 64 that are in pressure contact with each other. And the 2nd roll 41b, the 3rd roll 50, and the 4th roll 64 are arrange | positioned in this order along the rotation direction in the state which located the 1st roll 49 in the center. A guide member 42 that guides the folded sheet along the peripheral surface of the first roll 49 is disposed between the third roll 50 and the fourth roll 64.

  Then, the sheet is primarily folded at the pressure contact portion Np1 between the second roll 41b and the first roll 49, the sheet is secondarily folded at the pressure contact portion Np2 between the first roll 49 and the third roll 50 on the downstream side, and then the first roll The folded sheet is further folded at 49 and the pressure contact portion Np3 of the fourth roll 64.

  A device configuration of the folding processing unit 48 will be described. Reference numeral 44 shown in FIG. 5A denotes an apparatus frame, which illustrates the front side of the front and rear side frame frames (front and rear in FIG. 5) of the apparatus housing that face each other. The rolls 49, 41b, 50, 64 are rotatably supported between the front and rear side frame frames 44 (hereinafter, the pair of front and rear side frame frames are simply referred to as “device frames”).

At this time, the first roll 49 is supported by the apparatus frame 44 via the first bracket member 45, and the fourth roll 64 is supported by the apparatus frame 44 via the second bracket member 46. The guide member 42 is supported by the second bracket member 46.
This is because the first bracket member 45 separates the first roll 49 from the second third rolls 41 b and 50, and the second bracket member 46 separates the fourth roll 64 from the first roll 49.

  For this reason, as shown in FIG. 6, the present invention configures the positional relationship of the first to fourth rolls 49, 41b, 50, 64 as follows. The second and third rolls 41b and 50 are brought into pressure contact with the outer periphery of the first roll 49 at the right hemisphere portion (angle interval within 180 degrees), and the fourth roll 64 is brought into pressure contact with the left hemisphere portion (angle interval outside 180 degrees). . In FIG. 6, the second third rolls 41b and 50 are pressed against each other within 180 degrees on the right side with respect to the vertical line zz, and the fourth roll 64 is pressed within 180 degrees on the left side.

  Such a positional relationship, that is, the second roll 41b and the third roll 50 are set to the first roll 49 at the angular position between 0 degrees and 180 degrees with the vertical line zz passing through the circle center of the first roll 49 as the base point. It arrange | positions on the outer periphery of a roll, and the 4th roll 64 is press-contacted similarly to the angular position between 180 degree | times and 360 degree | times. As a result, the second and third rolls 41b and 50 are fixed to the apparatus frame, and the first and fourth rolls 49 and 64 can be moved at the same time to simultaneously release the three pressure contacts. In addition, the second third rolls 41b and 50 can be arranged in the right hemisphere portion of the first roll 49, and the fourth roll 64 can be arranged in the left hemisphere portion, so that the roll mechanism can be made compact and compact.

Therefore, the second and third rolls 41b and 50 are supported by the apparatus frame 44 at an angular interval of 180 degrees or less. In FIG. 6, the rotation shaft 41x of the second roll 41b is rotatably supported by the apparatus frame 44, and similarly, the rotation shaft 50x of the third roll 50 is also supported by the bearing.
On the other hand, the first roll 49 is supported by the first bracket member 45, and the bracket member 45 is supported by the device frame 44 by the support shaft 45r. The support shaft 45r is set at a central position for swinging the first roll 49 in a direction away from the second and third rolls 41b and 50.

  The first bracket member 45 is subjected to a spring force in the direction indicated by an arrow from an urging spring (urging means) 47 having one end fixed to the apparatus frame 44, and the first roll 49 is moved to the second and third rolls 41 b and 50. Is in pressure contact.

  On the other hand, the fourth roll 64 is attached to the second bracket member 46, and the second bracket member 46 is supported by the apparatus frame 44 so as to be swingable by a support shaft. A guide member 42 is attached to the second bracket member 46, and the guide member 42 is curved between the third roll 50 and the fourth roll 64 to guide the folded sheet along the peripheral surface of the first roll 49. It is formed into a shape.

  The position of the support shaft of the second bracket member 46 is set so that the fourth roll 64 and the guide member 42 can swing on the apparatus frame 44 in the direction away from the first roll 49. In the illustrated example, the support shaft is set to the rotation shaft 50 x of the third roll 50. This support shaft may be set at a position other than the rotation shaft 50x.

  The fourth roll 64 is not directly attached to the second bracket member 46 but supported by a biasing lever 38 attached to the bracket. As shown in FIG. 5 (a), the urging lever 38 pivotally supports the fourth roll 64 at its tip, and its central portion is pivotally supported by the second bracket member 46 by the pivot 38r. A biasing spring 52 is engaged with the base end portion. One end of the urging spring 52 is fixedly supported by the second bracket member 46, and a spring force in the direction of the arrow is applied to the urging lever 38. The fourth roll 64 is pressed against the first roll 49 by this spring force.

Therefore, when the first bracket member 45 swings in the clockwise direction in FIG. 6 about the support shaft 45r, the first roll 49 is separated from the second and third rolls 41b and 50. Further, when the second bracket member 46 swings about the rotation shaft 50x in the counterclockwise direction of FIG. 6, the fourth roll 64 and the guide member 42 are separated from the first roll 49.
In this case, after the second bracket member 46 is moved in the direction in which the fourth roll 64 is separated from the first roll 49, the first bracket member 45 is moved to the first roll 49. It is necessary to move the position in a direction away from the head. This is to prevent the fourth roll 64 from interfering with the movement when the first roll 49 is moved in the separation direction (see FIG. 6).

  One of the first and second bracket members 45 and 46 is provided with an operating means 55, and when one is swung, the other is swung simultaneously. In the illustrated example, when the second bracket member 46 is swung around the rotation shaft 50x, the cam engagement portion 46c provided on this member presses the interlocking engagement portion 45z of the first bracket member 45, and the first bracket member 46 is pressed. The bracket member 45 is pivoted clockwise in FIG. 6 about the support shaft 45r.

  The illustrated apparatus shows a case where the operating means 55 is provided on the second bracket member 46. The second bracket member 46 is provided with a latch 56 for holding the member in the press contact position, and this latch is released. Then, the second bracket member 46 can swing in the counterclockwise direction in FIG. 6 about the rotation shaft 50x.

  The latch 56 includes a cam lever 56a and a latch groove 46w. The cam lever 56a is rotatably provided on the apparatus frame side, and an operation lever (first operation lever) 56b is integrally attached. In the state of FIG. 8A in which the tip of the cam lever 56a is engaged with the latch groove 46w, the second bracket member 46 is positioned at the operating position (posture).

  Therefore, when the operation lever 56b is operated to rotate the cam lever 56a in the clockwise direction in the drawing, the tip of the cam lever is disengaged from the latch groove 46w, and the second bracket member 46 freely rotates around the rotation shaft 50x (free state). Become.

  In the above, the second bracket member 46 is provided with a temporary latch 57. The temporary latching latch 57 has engaging claws 57a and 57b that are engaged with each other, one on the apparatus frame side and the other on the second bracket member side.

  The engaging claw 57a disposed on the second bracket member side is provided with an operating lever (second operating lever) 57c for releasing the latch engagement. When the operation lever 57c is rotated clockwise in the state of FIG. 8A, the temporary fixing latch 57 is released, and the second bracket member 46 freely rotates about the rotation shaft 50x.

  In this way, the second bracket member 46 has a three-stage posture of the engagement position (main latch position) Lp1, the first release position (temporary fastening latch position) Lp2, and the second release position (free state) Lp3. . Therefore, at the latch position Lp1, the first to fourth rolls 49, 41b, 50, and 64 are set to be in pressure contact with each other, and at the temporary fixing latch position Lp2, the first to fourth rollers are set to a loosely fitted state. In the state Lp3, the second bracket member 46 can be swung to a free angular position.

  Further, when the second bracket member 46 is moved from the engagement position Lp1 to the second release position Lp3 about the rotation shaft 50x, the cam engagement portion 46c is connected to the interlocking engagement portion 45z of the first bracket member 45. Press. Then, the first bracket member 45 is interlocked in the clockwise direction in FIG. 8A around the support shaft 45r, and swings the bracket member 45 in the separating direction. By this swinging, the first roll 49 is separated from the second third rolls 41b and 50, and the engagement of the press contact portions Np1 and Np2 is released.

The folding processing unit 48 is arranged in the apparatus housing 29 from the top to the bottom in the order of the sheet conveyance path (first conveyance path) 32, the folding roll means 49, 41b, 50, 64, and the storage stacker 65. The first roll 49, the second roll 41 b, the third roll 50, and the fourth folding roll 64 constituting the folding roll means are arranged above the storage stacker 65.
Accordingly, when taking out the sheet from the storage stacker 65, the operator may touch the roll pressure contact portion. At the same time, when a sheet jam occurs at the roll pressure contact portion, it is necessary to open the pressure contact portion. Therefore, a cover member 58 is provided on the second bracket member 46 as follows.

[Composition of cover member]
A cover member 58 is attached between the second switchback path 35 and the second bracket member 46 to prevent the user from holding his / her hand between the folding rollers when a jam occurs. The cover member 58 is made of a flexible resin film member, the base end portion 58a of the cover member 58 is fixed to the guide member of the second switchback path 35 (see FIG. 7), and the tip end portion 58b of the second switchback path 35 is a second member. The pin 46p provided on the bracket member 46 is engaged and supported by a slit 58s.

A pair of second bracket members 46 are arranged opposite to each other at both ends in the axial direction of the folding roll, and a cover member 58 is attached between the pair of bracket members.
Therefore, the cover member 58 covers the storage stacker 65 and the roller pressure contact portions Np2, Np3 located below when the second bracket member 46 is in an operating state. Further, when the second bracket member 46 is in the open state, the operator can approach the roller pressure contact portion from the storage stacker 65.

[Configuration of full detection sensor]
The second bracket member 46 is provided with a full detection lever 60 that detects the uppermost sheet of the storage stacker 65. This may damage the detection lever when the operator opens the second bracket member 46 and performs jamming. Therefore, by opening the detection lever 60 integrally with the second bracket member 46, the detection lever 60 is retreated from the jam processing work area. Sd in the figure is a sensor that detects the detection lever 60.

[Shift motor drive mechanism]
Next, the drive mechanism of the primary folding deflection means 53 and the secondary folding deflection means 54 will be described. As shown in FIG. 10, the primary folding deflector 53 is supported by a follower roller 53a and a curved guide 53b that move up and down with a predetermined stroke. The lifting member 53c is provided with an operating lever 85a that can swing around a support shaft 85x. That is, the elevating member 53c supported by the apparatus frame by a guide rail (not shown) so as to be movable up and down is provided with a cam groove 53d, and the cam groove 53d is disposed so that the tip of the operating lever 85a engages. .

  The operating lever 85a is connected to the support shaft 85x via a spring clutch 85d. At the same time, a pulley 85b is provided on the support shaft 85x, and the rotation of the shift motor MS is transmitted to the pulley 85b by a transmission belt 85c. Therefore, the spring clutch 85d is set to transmit the rotation of the shift motor MS from the support shaft 85x to the operating lever 85a. At the same time, the spring clutch 85d is idled between the support shaft 85x and a rotation of the shift motor MS is not transmitted to the operating lever 85a when a load exceeding a predetermined torque is applied.

  Therefore, if the shift motor MS is rotated in the forward direction, the operating lever 85a is rotated clockwise from the state shown in FIG. 10A to the state shown in FIG. 10B, and the driven roller 53a is moved to the circumferential surface of the first roll 49. After the contact, the spring clutch 85d is idled. When the shift motor MS is rotated in the opposite direction, the operating lever 85a is raised from the state shown in FIG. 5B to the state shown in FIG. 5A, and after the elevating member 53c hits the stopper 53e, the spring clutch 85d is idled. Thus, it is locked in the illustrated state. A limit sensor Ls is disposed at this position, and the rotation of the shift motor MS is stopped by a state signal when the elevating member 53c is moved to a predetermined stopper position.

  On the other hand, the secondary folding deflecting means 54 is similarly supported by the apparatus frame so that the elevating member 54c moves up and down with a predetermined stroke, and is provided with a driven roller 54a and a curved guide 54b. As described above, the lifting member 53c is provided with the rack 54r and meshes with the pinion 54p. Therefore, a shift motor MS is connected to the pinion 54p via a spring clutch 86a. The spring clutch 86a is set to transmit the rotation of the shift motor MS within a predetermined torque and to idle at a predetermined torque or more.

  The primary folding deflection means 53 and the secondary folding deflection means 54 move the elevating member 53c from the retracted position to the operating position by the forward rotation of the shift motor MS, and the secondary folding deflection means by the rotation in this direction. The elevating member 54c is moved from the operating position to the retracted position. On the other hand, in the reverse rotation of the shift motor MS, the elevating member 54c of the secondary folding deflector 54 is moved from the retracted position to the operating position, and in this rotational direction, the elevating member 53c of the primary folding deflector 53 is moved from the operating position to the retracted position. Move position. In this way, the primary folding deflecting means 53 and the secondary folding deflecting means 54 are configured to reciprocally move between the operating position and the retracted position by forward and reverse rotation of the shift motor MS.

[Sheet edge detection sensor]
As shown in FIG. 3, the first sensor S <b> 1 that detects the edge of the sheet is disposed in the first conveyance path 32 described above, and the edge (leading edge and trailing edge) of the sheet that is carried into the first switchback path 34. Is detected. A second sensor S2 for detecting the edge of the sheet carried into the second switchback path 35 is disposed. The first sensor S1 and the second sensor S2 detect the edge of the sheet in order to determine the fold position of the sheet, and the operation thereof will be described later together with the folding specification described later.

[Folding specification]
Next, a sheet folding method by the above folding processing means will be described with reference to FIG. A sheet on which an ordinary image is formed may be folded in two or three for letter finishing. Further, when folding three times, there are cases where the outer three and the inner three are folded. FIG. 14A shows an inner three-fold, FIG. 14B shows an outer three-fold, and FIG. 14C shows a Z-fold.

  In the case of folding in half, the sheet sent to the second conveyance path 33 is moved to the 1/2 position of the sheet size by the first and second rolls 49 and 41b or the 1/2 position leaving a margin at the end of the sheet. Fold together (primary fold).

  Further, in the case of folding in three, the sheet sent to the second conveyance path 33 is folded at the 1/3 position of the sheet size by the first and second rolls 49 and 41b (primary folding). The folded sheets are folded by the first third rolls 49 and 50 at the 1/3 position (secondary folding) and sent to the third transport path 36.

  In the case of folding in three, when the inner three is folded as shown in FIG. 14A, the sheet fed to the second transport path 33 is fed by the first second roll 49, 41b to the sheet rear end side 1 / The three positions are folded, and then the sheet leading end side 1/3 position is folded. Similarly, when the sheet is folded three times outwardly, the sheet fed to the second conveyance path 33 is folded at the 1/3 position of the sheet leading end side by the first and second rolls 49 and 41b, and then the sheet trailing end side 1/3 position is set. Fold together.

  When the sheet is further folded in three and Z-folded as shown in FIG. 14 (c), the sheet fed to the second transport path 33 is folded at the 1/4 position on the sheet trailing edge side by the first and second rolls 49 and 41b. Align and then fold the 1/2 position of the sheet.

  In addition, there is a case where a margin is left by widening the folding width of three folds according to the envelope size. In the case of folding the inner three as shown in FIG. 14D, the rear end side is folded slightly (primary folding) from the 1/3 position of the sheet size (primary folding), and then the sheet width is substantially the same as the primary folding. Fold at the width position (secondary folding). Similarly, in the case of the three outer folds shown in FIG. 14 (e), the front end side is folded slightly from the 1/3 position on the front end side of the sheet, and then the rear end side of the sheet is folded at a position substantially the same width as the sheet width. Match (secondary folding). That is, when a margin is left on the three-fold sheet, the sheets are folded so that the side of the secondary folded sheet becomes longer.

[Control means]
The control means 95 for folding the sheet is configured as follows. A control CPU is mounted on the sheet folding device B described above, or a folding processing control unit is provided in the control unit 91 of the image forming apparatus A. The control unit is configured so that the following operation is possible.

  First, stopper means (not shown) for regulating the position of the sheet leading edge in the first switchback path 34 and the second switchback path 35 of the second conveying path 33, or sensor means (S1, S2 shown in the figure) for detecting the position of the sheet leading edge. ). In the illustrated apparatus, the first sensor S1 is arranged on the first switchback path 34, and the second sensor S2 is arranged on the second switchback path 35. The control unit 95 is configured to calculate the timing at which the sheet fold position reaches a predetermined position based on the sheet size information sent from the image forming apparatus A and the detection signal from the sensor S1 (S2).

  Therefore, description will be made according to the control block diagram shown in FIG. In the image forming apparatus A, the control CPU 91 is provided with a control panel 15 and a mode setting unit 92. The control CPU 91 controls the paper feeding unit 3 and the image forming unit 7 according to the image forming conditions set on the control panel 15. Then, the control CPU 91 transfers data and commands necessary for post-processing such as “post-processing mode”, “job end signal”, and “sheet size information” to the control unit 95 of the post-processing apparatus C.

  The control unit 95 of the post-processing apparatus C is a control CPU and includes a post-processing operation control unit 95a. The control CPU 95 receives detection signals from the first sensor S1 and the second sensor S2. Further, the control CPU 95 transmits an “ON” and “OFF” control signal to the path switching means 63.

  The control CPU 95 stores in the ROM 96 a folding process execution program for controlling the conveyance motor Mf (not shown), the shift motor MS, and the path switching means 63 so as to execute the folding specifications described above. The RAM 98 stores data for calculating the sheet crease by the crease position calculation means 97 and the operation timing time of the shift motor MS as data.

  The crease position calculation means 97 is an arithmetic circuit that calculates the crease position (dimension) from the leading end of the sheet (distal end in the paper discharge direction) from the “sheet length size”, “folding specification”, and “margin dimension”. It is configured. For example, in the two-fold mode, the sheet is folded at a 1/2 position in the paper discharge direction, or folded at a 1/2 position leaving a preset margin. The calculation of the crease position is, for example, calculated by [{(sheet length size) − (margin)} / 2]. In the three-fold mode, the fold position is calculated according to the folding specifications such as letter folding (inner three-fold, outer three-fold), filing fold (Z-fold, outer three-fold).

[Folding operation]
The operation of the configuration of the sheet folding apparatus B will be described. FIG. 11A shows a state in which the sheet that has entered the carry-in entrance 30 is corrected, and FIG. 11B shows a state in which the sheet has been carried into the first switchback path 34 for primary folding. 12A shows a state where the sheet is folded at the primary folding position Np1, FIG. 12B shows a state where the folded sheet is carried into the second switchback path 35, and FIG. 13A shows a secondary folding position Np2. FIG. 13B shows a state in which the folded sheet is carried out.

  In FIG. 11A, the sheet is guided to the carry-in entrance 30 and is sent downstream by the carry-in roller pair 40. Then, the leading end of the sheet is locked by the stopper member 43 and is bent and deformed in a loop shape within the registration area, so that the leading ends are aligned.

  In FIG. 11B, when the stopper member 43 is retracted from the first conveyance path 32, the sheet is fed to the downstream side of the first conveyance path 32 by the sheet conveyance mechanism described above. Then, the control means 95 controls the path switching means 63 to guide the seat from the first path 32 to the first switchback path 34 as shown.

  Then, the sheet is carried into the first switchback path 34 by the pinch roller 41a and the second roll 41b. A first sensor S1 is disposed on the first conveying path 32 on the downstream side of the pinch roller 41a and the second roll 41b, and detects the leading edge of the sheet carried into the first switchback path 34.

  In FIG. 12A, the control means 95 moves the elevating member 53c of the primary folding deflecting means 53 at the timing when the sheet fold position is transferred to a predetermined position based on the signal detected by the first sensor S1. Move from the standby position to the operating position. Then, the sheet in the first conveyance path 32 is deformed into a V shape toward the first nip portion Np1. When the driven roller 53a attached to the elevating member 53c comes into pressure contact with the peripheral surface of the first roll 49, the leading end of the sheet is fed out in the opposite direction (the rotation direction of the first roller).

  On the other hand, the sheet rear end side feeds the sheet toward the first nip portion Np1 by the conveying force of the pinch roller 41a and the second roll 41b. At this time, the curved guide surface of the curved guide 53b regulates the sheet along the roller circumferential surface so as to follow the circumferential surface of the second roll 41b.

  Accordingly, the sheet is fed to the primary folding position Np1 by the driven roller 53a on the leading end side, the pinch roller 41a and the second roll 41b on the trailing end side toward the first nip portion Np1, and the lifting timing of the lifting member 53c is adjusted. The crease position will be determined. Therefore, the control means 95 determines the speed at which the sheet is transferred by the pinch roller 41a and the second roll 41b, and the timing at which the driven roller 53a is moved from the standby position to the operating position (particularly, the driven roller 53a contacts the peripheral surface of the first roll 49. (Timing) is previously set to an optimum value by experiment.

  Since the curved guide surface of the curved guide 53b guides the sheet along the peripheral surface of the opposing second roll 41b in synchronization with the movement of the driven roller 53a from the standby position to the operating position, the sheet fold position However, there is no fear of changing each time.

  In FIG. 12B, the sheet that has been folded at the first nip portion Np1 at the 1/2 position (2 folds), 1/3 position (3 folds), and 1/4 position (3 folds) A conveyance force is applied at the first nip portion Np1, and the sheet is sent downstream. Therefore, the control means 95 positions the elevating member 54c of the secondary folding deflecting means 54 in the operating position in the two-fold mode and in the standby position in the three-fold mode. This figure shows the control in the three-fold mode. When folding in two, the elevating member 54c is positioned at the operating position, and the folded sheet is guided from the tip to the second nip portion Np2 and sent to the carry-out port 31 on the downstream side.

  Therefore, in the three-fold mode, the control means 95 positions the elevating member 54c of the secondary folding deflecting means 54 at the standby position as shown in FIG. Then, the sheet sent from the first nip portion Np1 is sent from the leading edge to the second switchback path 35. Then, the second sensor S2 detects the leading end (fold position) of the sheet.

  In FIG. 13A, the control means 95 moves the elevating member 54c of the secondary folding deflecting means 54 from the standby position when the secondary folding position reaches the predetermined position based on the detection signal of the second sensor S2. Move to operating position. Then, the sheet in the second switchback path 35 is fed out in the opposite direction when the driven roller 54a comes into contact with the peripheral surface of the third roll 50.

  As a result, the front end side of the sheet is driven by the driven roller 54a, and the rear end side is fed by the first nip portion Np1 in the opposite direction to guide the sheet to the second nip portion Np2. In this case, the movement timing of the elevating / lowering member 54c from the standby position to the operating position is the same as in the case of the primary folding deflecting means 53 described above, and the operation of the guide member 54b is also the same.

  In FIG. 13B, the folded sheet sent to the secondary folding position (second nip portion) Np2 is reliably folded by the additional folding roller 64 in pressure contact with the first roll 49, and the third conveyance is performed. It is transferred to the path 36. Therefore, the control means 95 sends the folded sheet to the paper discharge path 37 or returns it to the first transport path 32 with a preset sorting specification. The illustrated apparatus controls the path switching flapper 38 and guides it from the paper discharge path 37 to the storage stacker 65 in the case of letter folding specifications of inner folding and outer folding, which need not be bound by the post-processing apparatus C. To do.

  Further, in a three-fold mode such as two-folding or 1 / 4Z-folding that requires post-processing such as filing or bookbinding and binding processing, the sheet is transferred from the third transport path 36 to the first transport path 32, and the transport outlet 31. To post-processing device C.

[Folding operation in 2-fold mode]
In the above-described folding operation, in the mode in which the sheet is folded in half, as shown in FIG. Then, the control means 95 calculates the crease position by the crease position calculation means 97 (St01). Therefore, in the two-folding mode (St02), the control unit 95 detects the leading edge of the sheet (St03). The primary folding deflecting means 53 is moved from the standby position to the operating position after the passage of the sheet feeding time corresponding to the length of the sheet calculated by the fold position calculating means 97 from this detection signal (St04) (St05). This movement is controlled by the rotation of the shift motor MS.

  In the process in which the elevating member 53c of the primary folding deflector 53 moves to the operating position, the sheet on the first transport path 32 is directed toward the first nip portion Np1 with reference to the fold position as described with reference to FIG. It is distorted. When the driven roller 53a of the primary folding deflecting means 53 comes into contact with the peripheral surface of the first roll 49, the sheet is dragged and inserted from the fold position into the first nip portion Np1.

  At this time, in the two-fold mode, the control means 95 moves the secondary folding deflecting means 54 after the estimated time when the sheet fold is inserted into the first nip portion Np1 with reference to the detection signal from the first sensor S1 (St06). It moves to the operating position (St07). This estimated time is set to a time before the fold position of the sheet is inserted into the first nip portion Np1 and the leading end of the folded sheet reaches the curved guide 54b. Therefore, the leading edge of the folded sheet is guided by the curved guide surface of the curved guide 54b and is along the circumferential surface of the second roller.

  At the same time, since the driven roller 54a positioned at the operating position rotates following the rotation of the third roll 50, even if the leading end of the folded sheet is curled in a direction deviating from the second nip portion Np2, the driven roller 54a As the third roll 50 rotates, it is reliably guided to the second nip portion Np2.

  Therefore, the control means 95 carries out the folded sheet carried out from the second nip portion Np2 to the third transport path 36 to the first transport path 32 from the third transport path 36. Then, the control means 95 prepares for the subsequent sheet processing with the secondary folding deflecting means 54 positioned at the operating position (St08). The illustrated one has a relationship in which the primary folding deflecting means 53 is positioned at the standby position, and the secondary folding deflecting means 54 that moves in the opposite direction is positioned at the operating position. It is also possible to configure so that the secondary folding deflecting means 54 is moved to the standby position by the detection signal of the paper discharge sensor S3.

[Folding operation in 3-fold mode]
In the mode in which the sheet is folded in three, as described with reference to FIGS. Then, the control means 95 calculates the crease position by the crease position calculation means 97 (St01). Therefore, in the three-fold mode (St09), the control unit 95 detects the leading edge of the sheet (St10).

  The primary folding deflecting means 53 is moved from the standby position to the operating position (St12) after elapse of a sheet feeding time corresponding to the length of the sheet calculated by the fold position calculating means 97 from this detection signal (St11). This movement is controlled by the rotation of the shift motor MS.

  In the process in which the elevating member 53c of the primary folding deflector 53 moves to the operating position, the sheet on the first transport path 32 is directed toward the first nip portion Np1 with reference to the fold position as described with reference to FIG. It is distorted. When the driven roller 53a of the primary folding deflecting means 53 comes into contact with the peripheral surface of the first roll 49, the sheet is dragged and inserted from the fold position into the first nip portion Np1. At this time, the control means 95 waits for the second sensor S2 to detect the leading edge of the sheet in the three-fold mode (St13).

  Based on the signal that the second sensor S2 detects the leading edge of the sheet, the control means 95 moves the secondary folding deflecting means 54 to the operating position after the expected time that the secondary fold position of the sheet reaches the predetermined position (St14). (St15). This estimated time is set by the calculated value of the crease position calculating means 97. Therefore, the sheet is inserted into the second nip portion Np2 with a conveying force applied from the driven roller 54a. The front end of the sheet is detected by the paper discharge sensor S3, and it is carried out from the third conveyance path 36 to the first conveyance path 32 according to the folding specification, or is carried out from the paper discharge path 37 to the storage stacker 65 (St16).

  When the post-processing mode in which the sheet folding process is not performed is set from the mode setting unit 92 in step St01, the sheet is fed toward the carry-out roller pair 62. In the first path 32, the sheet guide 61 feeds the leading end of the sheet to the nip portion of the carry-out roller pair 62. Therefore, the sheet is smoothly guided to the unloading port (unloading unit) 31 without being subjected to stress of the gate stopper 43, the pinch roller 41a, and the second roll 41b.

[Output path configuration]
As described above, the folded sheet that is folded in half is fed to the third conveyance path 36 from the pressure contacts of the first and third rolls 49 and 50. Then, the sheet is further folded by an additional folding roller (fourth roll) 64 that is in pressure contact with the first roll 49 and guided to the third transport path 36. The third transport path 36 joins the first transport path 32 as described above. A paper discharge path 37 is branched from the third transport path 36 and is continuously provided via a path switching flapper 38, and the paper discharge path 37 is folded into a storage stacker 65 disposed below the second transport path 33. To guide you.

  Therefore, sheets that are folded in letter specifications, such as inner three-fold or outer three-fold, that do not need to be transferred to the post-processing apparatus C, are stored in the storage stacker 65 without being transferred to the carry-out port 31.

  Of the folded sheets sent to the third conveyance path 36, the sheet to be transferred to the post-processing apparatus C and to be post-processed is transferred toward the outlet 31 by the pair of carry-out rollers 62. In this case, the determination as to whether or not to perform post-processing is configured such that, for example, the post-processing conditions are set simultaneously with the image forming conditions on the control panel 15 described above. Then, it is configured to be carried out to the storage stacker 65 or to be transferred to the post-processing apparatus C according to the set finishing conditions.

[Image forming apparatus]
The image forming apparatus A has the following configuration as shown in FIG. This apparatus sends a sheet from the sheet feeding unit 3 to the image forming unit 7, prints the sheet on the image forming unit 7, and then carries out the sheet from the main body discharge port 18. The sheet feeding unit 3 stores sheets of a plurality of sizes in sheet feeding cassettes 4 a and 4 b, and separates designated sheets one by one and feeds them to the image forming unit 7. The image forming unit 7 includes, for example, an electrostatic drum 8, a print head (laser light emitting device) 9 and a developing device 10 arranged around the electrostatic drum 8, a transfer charger 11, and a fixing device 12. An electrostatic latent image is formed by the light emitting device 9, toner is attached to the developing device 10, an image is transferred onto the sheet by the transfer charger 11, and heat fixing is performed by the fixing device 12.

  The sheets on which images are formed in this way are sequentially carried out from the main body discharge port 18. 13 is a circulation path. The sheet printed on the front surface side from the fixing device 12 is turned upside down via the main body switchback path 14 and then fed again to the image forming unit 7 to be printed on the back surface side of the sheet. This is the path for duplex printing. The sheet printed on both sides in this way is turned upside down by the main body switchback path 14 and then carried out from the main body discharge port 18.

  An image reading unit 20 shown in FIG. 1 scans an original sheet set on the platen 21 with a scan unit 22 and electrically reads it with a photoelectric conversion element (not shown). The image data is digitally processed by an image processing unit, for example, and then transferred to the data storage unit 16 to send an image signal to the laser emitter 9. Reference numeral 25 denotes a feeder device that feeds a document sheet stored in the stacker 26 to the platen 21.

  The image forming apparatus A having the above-described configuration is provided with a control unit (controller) (not shown), and image forming conditions such as sheet size designation, color / monochrome printing designation, print number designation, single-sided / double-sided printing designation, and enlargement from the controller panel 15. -Printout conditions such as reduced print designation are set.

  On the other hand, in the image forming apparatus A, image data read by the scan unit 22 or image data transferred from an external network is accumulated in the data storage unit 16, and the image data is transferred from the data storage unit 16 to the buffer memory 17. The data signal is sequentially transferred from the buffer memory 17 to the print head 9.

  From the controller panel 15, the post-processing conditions are also input and designated simultaneously with the image forming conditions. As the post-processing conditions, for example, “print-out mode”, “staple binding mode”, “sheet bundle folding mode”, or the like is selected. As the post-processing conditions, the folding specifications in the sheet folding apparatus B described above are set.

[Post-processing equipment]
As shown in FIG. 2, the post-processing device C has the following configuration. This apparatus includes a sheet receiving port 69, a sheet discharge stacker 70, and a post-processing path 71 in an apparatus housing 68. The sheet receiving port 69 is connected to the carry-out port 31 of the above-described sheet folding apparatus B, and is configured to receive a sheet from the first conveyance path 32 or the third conveyance path 36.

  The post-processing path 71 is configured to guide the sheet from the sheet receiving port 69 to the paper discharge stacker 70, and a processing tray 72 is provided in this path. Reference numeral 73 in the drawing denotes a paper discharge port for collecting sheets from the post-processing path 71 on a processing tray 72 arranged on the downstream side. A punch unit 74 is disposed in the post-processing path 71. A paper discharge roller 75 is disposed at the paper discharge port 73, and sheets from the sheet receiving port 69 are stacked on the processing tray 72.

  The processing tray 72 switches back the sheet from the post-processing path 71 (conveying direction reverse) and collects and aligns it on a rear end regulating member (not shown) provided on the tray. For this reason, a forward / reverse roller 75 for switching back the sheet from the sheet discharge port 73 is provided above the tray. Further, the processing tray 72 is connected to the paper discharge stacker 70, and the sheet from the paper discharge port 73 is supported by the paper discharge stacker 70 at the front end side and the processing tray 72 at the rear end side (bridge support).

  The processing tray 72 is provided with a stapler unit 77 for binding the sheet bundle positioned on the rear end regulating member. Reference numeral 78 shown in the figure denotes alignment means that aligns the sheets carried on the processing tray in the direction perpendicular to the conveyance direction. Reference numeral 79 denotes a paddle rotating body, which is drivably coupled to the rotation shaft of the paper discharge roller 75 so as to transfer the sheet from the paper discharge roller 75 toward the trailing edge regulating member.

  Reference numeral 80 in the drawing denotes sheet bundle carrying-out means, which transfers the sheet bundle bound together by the stapler unit 77 to the sheet discharge stacker 70 on the downstream side. For this reason, the illustrated sheet bundle carrying-out means 80 includes a lever member 81 whose base end is pivotally supported so as to be swingable, and a sheet end engaging member 82.

  The sheet end engaging member 82 is mounted on the processing tray so as to reciprocate in the paper discharge direction along the processing tray 72, and is connected to the lever member 81. In the drawing, Mm is a drive motor that swings the lever member 81. Although not shown, the paper discharge stacker 70 is provided with an elevator mechanism that moves up and down according to the amount of stacked sheets.

30 Carriage entrance (carry-in part)
31 Unloading port (unloading part)
32 First transport path (sheet transport path)
33 Second transport path (folding path)
34 First switchback path (first reverse path)
35 Second switchback path (second reverse path)
37 Paper discharge path 38 Energizing lever 41b First roll (folding roller means)
41x Rotating shaft 42 Guide member 44 Device frame (side frame)
45 First bracket member 45r Support shaft 45z Interlocking engagement portion 46 Second bracket member 46c Cam engagement portion 46w Latch groove 47 Energizing spring (urging means)
48 Folding processing part 49 Second roll (folding roller means)
50 Third roll (folding roller means)
50x Rotating shaft 52 Biasing spring (Biasing means)
53 Primary folding deflecting means 54 Secondary folding deflecting means 55 Operating means 56 Latch 56a Cam lever 56b Operating lever (first operating lever)
57 Temporary fixing latch 57a Engaging claw 57b Engaging claw 57c Operation lever (second operation lever)
58 Cover member 64 Fourth roll Np1 First folding position (first nip portion: pressure contact portion)
Np2 second folding position (second nip part: pressure contact part)
Np3 pressure weld

Claims (12)

A folding path for folding the sheet sent from the carry-in section;
Folding roll means for forming a primary folding pressure welding part, a secondary folding pressure welding part and an increased folding pressure welding part;
A paper discharge path for guiding the sheet folded by the folding roll means to the carry-out section;
With
The folding roll means includes:
A roll press-contacted in the second, third and fourth order in the rotation direction of the first roll located in the center;
A guide member that guides the folded sheet along the peripheral surface of the first roll between the third roll and the fourth roll;
Consists of
The first roll is provided on the first bracket member, and the first bracket member is supported by the apparatus frame so as to be swingable so that the first roll is separated from the second roll and the third roll,
The fourth roll and the guide member are provided on a second bracket member, and the second bracket member is swingable so that the fourth roll and the guide member are separated from the first roll. And
The first bracket member and the second bracket member are interlocked with each other so as to separate the first roll, the fourth roll, and the guide member by operating means disposed on one of them. A sheet folding apparatus. On the outer periphery of the first roll, the second roll and the third roll are press-contacted at an angular interval of 180 degrees or less,
The sheet folding apparatus according to claim 1, wherein the first bracket member is supported by the apparatus frame so as to be swingable in a direction away from the second roll and the third roll. On the outer periphery of the first roll, the second roll and the third roll are at an angular position between 0 degrees and 180 degrees, and the fourth roll is 180 degrees with a vertical line passing through the circle center of the first roll as a base point. Arranged so as to be pressed against the angular position between 360 degrees,
The sheet folding apparatus according to claim 1, wherein the first bracket member swings so as to separate the first roll in conjunction with the second bracket member. The folding processing path is
A first reversing path for guiding the sheet sent from the carry-in portion to a primary folding pressure contact portion between the first roll and the second roll;
A second reversing path for guiding the folded sheet sent from the primary folding pressure contact portion to a secondary folding pressure contact portion between the first roll and the third roll;
A paper discharge path for guiding the folded sheet sent from the secondary folding pressure contact portion to the increased folding pressure contact portion between the first roll and the fourth roll;
The sheet folding apparatus according to claim 1, comprising: The second bracket member is axially supported by a rotation shaft of the third roll, and the second bracket member is supported so as to be swingable about the rotation shaft of the third roll. Item 2. The sheet folding device according to Item 1. The second roll and the third roll are fixedly supported at predetermined positions of the apparatus frame,
2. The seat according to claim 1, wherein the first roll is pressed against the second roll and the third roll by an urging means provided between the first bracket member and the apparatus frame. Folding device. The operating means is disposed on the second bracket member,
The sheet folding apparatus according to claim 6, wherein the second bracket member is provided with a cam engaging portion that moves the first bracket member in the separation direction. The second bracket member is provided with locking means for holding the fourth roll at a position in pressure contact with the first roll,
The operation means includes
A first operating lever for releasing the locking means;
A second operating lever that swings the second bracket member in the separating direction;
The sheet folding apparatus according to claim 7, further comprising: The sheet folding device according to claim 1, further comprising a device housing;
A sheet conveyance path that is arranged in the apparatus housing and transfers the sheet from the carry-in part to the carry-out part without folding the sheet;
A folded sheet accommodating portion for accommodating a folded sheet from the folding processing path;
With
The folding processing path is arranged in a direction crossing the sheet conveying path,
The sheet conveyance path, the folding roll means, and the folded sheet storage portion are arranged in this order from the top to the bottom in the apparatus housing,
A sheet folding device, wherein a cover member for preventing an operator from entering is provided between the folding roll means positioned above and the sheet storage portion positioned below. The cover member is made of a flexible resin film member,
The sheet folding apparatus according to claim 9, wherein the cover member is attached to the second bracket member. The pair of second bracket members are disposed opposite to each other at both ends in the axial direction of the fourth roll, and the cover member is attached between the pair of bracket members. The sheet folding apparatus according to 10. The folded sheet storage unit is provided with a detection sensor for detecting a stack amount of folded sheets,
The sheet folding apparatus according to claim 9, wherein the detection sensor is attached to the second bracket member.

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