JP2020104993A - Sheet pressing device and image formation system having the same - Google Patents

Abstract

To improve the quality of a sheet after additional-folding processing by suppressing a mark due to a fold from being left on a sheet portion when the sheet portion exists between a roller for additional-folding and the fold.SOLUTION: A sheet pressing device includes: a carry-in port 119 which receives a sheet previously formed into the Z-shape with two folds; an additional-folding roller 114 which is arranged on the downstream side of the carry-in port to press the fold; a lower side folding guide 111 which is arranged so as to face the additional-folding roller; a first movement mechanism which moves the additional-folding roller between the pressing position for pressing the fold by bringing the additional-folding roller close to the lower side folding guide and the retreat position where the additional-folding roller is moved from the pressing position with respect to the lower side folding guide in a direction apart from the sheet; a second movement mechanism which moves the additional-folding roller along the fold; sheet basis weight recognition means; and a control unit. The control unit adjusts the speed of moving the additional-folding roller along the fold on the basis of the basis weight of the sheet acquired by the sheet basis weight recognition means.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sheet pressing device that performs a folding process on a sheet and an image forming system such as a copying machine, a printer, a facsimile, or a complex machine thereof including the sheet pressing device.

Conventionally, in a sheet folding apparatus (post-processing apparatus) installed in an image forming system such as a copying machine or a printer, the thickness (fold height) of a fold portion formed on a sheet by folding processing is increased. For the purpose of prevention, there is known one in which a folding process is performed once on a sheet to form a fold, and then the fold is further pressed (an additional fold process) by another pressing member.

For example, in Patent Document 1, an additional folding mechanism configured by a plurality of pairs of rollers is arranged on the downstream side of a pair of folding rollers that perform a folding process on a sheet so as to be parallel to the pair of folding rollers. There is disclosed a sheet processing apparatus that performs an additional folding process without increasing the processing time by continuously applying a load to a folding part (fold) with a plurality of pairs of rollers.

Further, in Patent Document 2, a folding roller is provided between a folding roller that performs folding processing on a sheet (sheet) while passing through a nip of a pair of rollers, and a folding section between a lower guide plate and a folding section of the folded sheet. On the other hand, there is disclosed a sheet processing apparatus which is provided with a fold-enhancing roller that further folds the fold-enhancing roller and moves the fold-enhancing roller in a direction orthogonal to the sheet conveying direction.

JP 2012-153525 A JP, 2004-59304, A

In the sheet processing apparatus disclosed in Patent Document 1 described above, since a plurality of pairs of rollers of the additional folding mechanism are arranged in parallel with the pair of folding rollers, the direction of the fold of the sheet and the rotation of the rollers for the additional folding. From the viewpoint that the axis extends in the same direction and the fibers at the fold line are crushed, the additional fold effect is smaller than the method of performing additional fold by moving a re-pressurizing means such as a roller along the fold line. There is a problem.

Further, the sheet processing apparatus disclosed in Patent Document 2 described above presses the fold while moving the fold-enhancing roller in the direction orthogonal to the sheet transport direction, and thus the additional folding method disclosed in Patent Document 1 is adopted. Compared with, more efficient folding can be performed. However, in a sheet in which a plurality of sheet parts partitioned by a plurality of folds are folded and folded through the folds, such as Z-folding, a case where the additional fold roller directly contacts the fold and a case where the additional fold roller and the fold are There is a case where a sheet portion is interposed between the sheet and the sheet portion, and when the sheet portion is interposed between the fold-enhancing roller and the fold, a step is formed below the sheet portion due to the presence of the fold. In the sheet folding apparatus as disclosed in Patent Document 2, pressure is applied under the same condition regardless of whether or not the sheet portion is interposed between the fold line and the additional folding roller. When the fold line is pressed through the sheet, there is a problem that, especially in the case of a sheet having a small basis weight and easy to have a crease, a mark due to the fold line remains as a streak in the sheet portion due to a step due to the fold line.

Therefore, in order to solve the problems existing in the prior art, it is an object of the present invention to prevent the fold marks from remaining in the sheet portion when the sheet portion is present between the roller for additional folding and the fold. To improve the quality of the sheet after the additional folding process.

In view of the above object, the present invention, as a first aspect, is a sheet pressing for performing additional folding on a sheet in which three sheet portions partitioned by two folds formed by a folding process are folded in a Z shape. A device, which is arranged downstream of the carry-in port in the carrying-in direction and receives a sheet that is carried in from a predetermined carrying-in direction after two folds have been previously formed by a folding process, and presses the fold line. A first pressing member, a second pressing member that is arranged so as to face the first pressing member and that presses the fold in cooperation with the first pressing member, and the first pressing member. A pressing position for pressing the fold line disposed between the first pressing member and the second pressing member by moving the second pressing member closer to the second pressing member, and a direction away from the sheet from the pressing position. A first moving mechanism for moving the first pressing member with respect to the second pressing member between a retracted position and a second moving member for the second pressing member. And a second moving mechanism for moving the first pressing member along the fold line in a state where the first pressing member is moved to the pressing position, and a sheet base for acquiring basis weight information of the sheet. An amount recognizing unit and a control unit that controls operations of the first moving mechanism and the second moving mechanism are provided, and the control unit is provided between the first pressing member and the fold line. Is located and the basis weight of the sheet acquired by the sheet basis weight recognition means is smaller than a predetermined value, the basis weight of the sheet is greater than or equal to a predetermined value. A sheet pressing device for controlling the second moving mechanism so as to increase the speed at which the first pressing member moves along the fold line.

In the above-described sheet pressing device, the fold line formed in advance on the carried-in sheet is arranged between the first pressing member and the second pressing member, and the first pressing member is attached to the second pressing member. By moving the first pressing member along the fold while being moved to the pressing position, the additional folding of the fold of the sheet can be performed. Further, when the sheet portion is located between the first pressing member and the fold, a step due to the fold occurs between the sheet portion and the second pressing member, so that the basis weight of the sheet is small and a crease is easily formed. When the sheet portion and the fold line are pressed between the first pressing member and the second pressing member, the crease marks become streaks on the sheet portion sandwiched between the first pressing member and the fold line. It becomes easier to remain. However, in the above-described sheet pressing device, in the case of a sheet having a small grammage and in which marks due to folds are likely to remain, it is more likely that the gap between the first pressing member and the folds is greater than in the case of a sheet having large grammage and in which marks due to folds are hard to remain Since the speed of the first pressing member moving along the fold is increased when the sheet portion is located at, the time for pressing the sheet between the first pressing member and the second pressing member is shortened. , The total amount (working amount) of pressing force applied between the first pressing member and the second pressing member to the sheet portion and the fold is reduced, and the sheet portion sandwiched between the additional folding roller and the fold. In addition, it is possible to prevent the marks due to the folds from remaining as streaks.

In the above-described sheet pressing device, the control unit is configured such that the sheet portion is located between the first pressing member and the fold, and the basis weight of the sheet acquired by the sheet basis weight recognition unit is predetermined. When the value is equal to or more than the value, the second moving mechanism is controlled so that the moving speed of the first pressing member along the fold is slower than that when the first pressing member directly faces the fold. Preferably. When the sheet portion is located between the first pressing member and the fold, the pressing force applied by the first pressing member is dispersed by the sheet portion and the pressing force acting on the fold is reduced, so that the fold is not strengthened. May be sufficient. However, in the case of a sheet having a large grammage and hardly leaving marks due to folds, when the sheet portion is located between the first pressing member and the fold, the speed of movement of the first pressing member along the fold is slowed. Then, the time for pressing the sheet between the first pressing member and the second pressing member becomes long, and the sheet portion and the fold are provided between the first pressing member and the second pressing member. The total amount of pressing force (work load) increases. Therefore, in the case of a sheet having a small crease having a small crease, it is possible to prevent crease marks from remaining on the sheet portion, and in the case of a sheet having a large grammage and a crease hardly leaving a mark, When the sheet portion is located between the pressing member and the fold, the influence of the reduction in the pressing force that acts on the fold due to the dispersion of the pressing force by the sheet portion is offset, and the effect of strengthening the fold is sufficiently obtained. Is possible.

Further, the control unit, when the first pressing member directly faces the fold, makes the speed of movement of the first pressing member along the fold the same regardless of the basis weight of the sheet. Thus, it is preferable to control the second moving mechanism. When the first pressing member directly faces the fold, the first pressing member directly presses the fold, so that the speed of movement of the first pressing member along the fold is the same regardless of the basis weight of the sheet. However, there is no fear that the crease marks will remain as streaks on the sheet portion, and the control is simplified.

In the above case, the control unit is configured such that the sheet portion is located between the first pressing member and the fold, and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is smaller than a predetermined value. Is smaller, the second moving mechanism is controlled so that the speed of movement of the first pressing member along the fold is faster than when the first pressing member directly faces the fold. It is preferable.

Further, when the sheet portion is located between the first pressing member and the fold and the basis weight of the sheet acquired by the sheet basis weight recognition means is equal to or larger than a predetermined value , The second movement so as to increase the number of times of movement of the first pressing member along the fold with respect to one fold, as compared to when the first pressing member directly faces the fold. The mechanism may be controlled. Increasing the number of movements of the first pressing member along the fold also lengthens the time for pressing the sheet between the first pressing member and the second pressing member, and the first pressing member and the second pressing member are pressed. It is possible to increase the total amount of pressing force (work amount) applied between the pressing member and the sheet portion and the folds. Therefore, in the case of a sheet having a large grammage and hardly leaving marks due to folds, when the sheet portion is located between the first pressing member and the fold, the movement of the first pressing member along the fold with respect to one fold By increasing the number of times, while suppressing the trace of creases remaining on the sheet part, the influence of the reduction of the pressing force that acts on the folds due to the dispersion of the pressing force by the sheet part is offset, and the effect of strengthening the folds is further increased. It is possible to raise it.

As one embodiment, the first pressing member may be an additional folding roller that rotates around a rotation axis extending in the sheet carrying-in direction.

Further, the sheet pressing device further includes a supporting portion and an elastic member, the first pressing member is supported by the supporting member via the elastic member, and is directed by the elastic member toward the second pressing member. May be biased.

When the sheet portion is located between the first pressing member and the fold and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is smaller than a predetermined value, the controller controls the The first pressing member is configured to weaken the pressing force applied to the fold between the first pressing member and the second pressing member, as compared with the case where the first pressing member directly faces the fold. The movement mechanism may be controlled. In the case of a sheet having a small grammage and easily leaving marks due to folds, if the pressing force applied to the folds is weakened when the sheet portion is located between the first pressing member and the folds, the first pressing member Since the total amount of pressing force (work amount) applied between the first pressing member and the fold is further reduced between the first pressing member and the fold, the sheet portion sandwiched between the first pressing member and the fold causes a crease. It is possible to further enhance the effect of suppressing the marks remaining as streaks.

Further, as a second aspect of the present invention, an image forming apparatus that forms an image on a sheet and carries out the image-formed sheet, and a sheet processing apparatus that performs a folding process on the sheet carried out from the image forming apparatus. And an image forming system including the sheet pressing device described above.

According to the present invention, in the case of a sheet in which the sheet portion is located between the first pressing member and the crease and the basis weight is small and crease marks are likely to remain, the sheet having a large grammage and the crease marks hardly remain Since the speed at which the first pressing member moves along the fold is made faster than in the case, the total amount of pressing force applied to the sheet portion and the fold between the first pressing member and the second pressing member ( The amount of work can be reduced, and it is possible to prevent the marks due to the folds from remaining as streaks in the sheet portion sandwiched between the additional folding roller and the folds. Therefore, it becomes possible to improve the quality of the sheet after the additional folding process while providing the effect of the additional folding.

FIG. 1 is an overall configuration diagram of an image forming system including a sheet pressing device of the present invention. FIG. 2 is an explanatory diagram showing main parts of a folding processing mechanism and an additional folding unit (corresponding to a sheet pressing device) of the folding processing device shown in FIG. 1. It is the figure which looked at the additional folding unit of the folding processing apparatus shown in FIG. 1 from the discharge port side. It is explanatory drawing which is provided in the inside of the additional folding unit shown in FIG. 3, and shows the mechanism which urges an additional folding roller toward a sheet|seat. 3 is a flowchart showing an operation of the folding processing device shown in FIG. 1. It is explanatory drawing which shows the operation|movement of the additional fold part when performing an additional fold process on a sheet|seat in an additional fold unit, (a) received the 1st fold located in the front end side of the sheet carrying direction in the additional fold part. The state, (b) is a state in which the additional folding roller is moved to the pressing position to press the first fold of the sheet with the additional folding roller, and (c) is the first position of the sheet at the pressing position shown in (b). The additional folding roller is moved along the fold line, and (d) shows the additional folding roller moved from the state shown in (c) to the first retracted position. It is explanatory drawing which shows the operation|movement of the additional fold part when performing an additional fold process on a sheet|seat in an additional fold unit, (e) receives the 2nd fold located in the rear end side of the sheet carrying direction in an additional fold part. (F) is a state in which the additional folding roller is moved to the pressing position and the second fold of the sheet is pressed by the additional folding roller, and (g) is the sheet at the pressing position shown in (f). The additional folding roller is moved along the second fold line, and (h) shows the additional folding roller moved from the state shown in (g) to the second retracted position. It is explanatory drawing which shows operation|movement of the additional folding part when performing an additional folding process on a sheet|seat in an additional folding unit, and (a) to (d) is each shown by (a) to (d) of FIG. The side view of the additional fold is shown. It is explanatory drawing which shows operation|movement of the additional folding part when performing an additional folding process on a sheet|seat in an additional folding unit, (e) to (h) is each shown by (e) to (h) of FIG. The side view of the additional fold is shown. It is a schematic diagram which shows the modification of the additional folding unit shown by FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, similar components will be designated with similar reference numerals.

First, with reference to FIG. 1, an overall configuration of an image forming system including a folding processing apparatus having an additional folding unit that is a sheet pressing apparatus according to the present invention will be described. The image forming system includes an image forming apparatus A, a folding processing apparatus B, and a post-processing apparatus C. The sheet S on which an image is formed by the image forming apparatus A is folded by the folding processing apparatus B. After that, the downstream post-processing apparatus C further performs stapling processing, aligning processing, and the like, if necessary, and discharges to the storage tray 27 on the downstream side. The image forming system includes various structures such as a copying machine, a printer, and a printing machine. Hereinafter, the image forming apparatus A, the folding processing apparatus B, and the post-processing apparatus C will be described in detail.

[Image forming device]
As shown in FIG. 1, the image forming apparatus A includes an image forming unit A1, an image reading unit A2, and an original feeding unit A3. The image forming unit A1 includes a paper feed unit 2, an image forming unit 3, a paper discharge unit 4, and a data processing unit 5 in the apparatus housing 1.

The paper feeding unit 2 includes a plurality of cassettes 2a, 2b, 2c, 2d, and each of the cassettes 2a, 2b, 2c, 2d can store sheets S of different standard sizes selected in advance. .. Each of the cassettes 2a, 2b, 2c, 2d has a built-in separation mechanism for separating the internal sheets S one by one and a paper feed mechanism for feeding out the sheets S. The sheet S stored in the sheet feeding unit 2 having such a configuration feeds the sheet S of a size designated by the main body control unit (not shown) to the sheet feeding path 6. The sheet feeding path 6 is provided with a conveyance roller 7 that is arranged at an intermediate portion and conveys the sheets S supplied from the plurality of cassettes 2a, 2b, 2c, and 2d to the downstream side, and each sheet S that is arranged at the end portion of the path is the leading edge of each sheet S. A registration roller 8 for aligning is provided, and the sheet S whose leading edge is aligned by the registration roller 8 is fed to the image forming unit 3 on the downstream side at a predetermined timing.

The image forming unit 3 may be configured to form an image on the sheet S sent from the paper feeding unit 2, and various image forming mechanisms can be adopted. In the illustrated embodiment, an electrostatic image forming mechanism is shown as the image forming unit 3. However, the image forming unit 3 is not limited to the electrostatic image forming mechanism shown in the figure, and an ink jet type image forming mechanism, an offset type image forming mechanism or the like may be adopted.

In the image forming section 3 shown in FIG. 1, a photoconductor 9 (drum, belt) and a light emitter 10 for emitting an optical beam to the photoconductor 9 are provided, and a developing device 11 (developer) and a cleaner are provided. (Not shown) is arranged around the rotating photoconductor 9. The one shown in the figure is a monochrome printing mechanism, in which a light emitter 10 optically forms a latent image on a photoconductor 9, and a toner ink is attached to the latent image by a developer 11. The ink image (ink toner) attached to the photoconductor 9 is image-transferred by the transfer charger 12 to the sheet S sent from the paper feeding unit 2, and after the image-transferred sheet S is fixed by the fixing roller 13, It is sent to the paper discharge path 14. Further, the image forming unit 3 is provided with a circulation path 17, and after the sheet S from the sheet discharge path 14 is turned upside down by the switchback path, it is sent again to the registration roller 8 to form an image on the back surface of the sheet S. The sheet is ejected and is sent to the sheet discharge path 14. A sheet discharge roller 15 is arranged in the sheet discharge path 14, and a sheet discharge port 16 is formed at the end thereof. The sheet S is conveyed from the sheet discharge port 16 to the folding processing apparatus B by the sheet discharge roller 15. To do.

A document reading unit A2 that optically reads a document image formed by the image forming unit 3 is provided above the image forming unit A1 configured as described above, and a document reading unit A2 is further provided above the document reading unit A2. The feeding unit A3 is mounted.

The image reading unit A2 includes a first platen 18 and a second platen 19 formed of transparent glass, a reading carriage 20, a light source mounted on the reading carriage 20, a photoelectric conversion element 21, a mirror and a lens. And a reduction optical system 22 configured in combination, and scans the reading carriage 20 along the first platen 18 to apply light from a light source to the image of the original sheet S placed on the first platen 18. The reflected light from the image of the original sheet S is guided to the photoelectric conversion element 21 by the reduction optical system 22 to read the image. The photoelectric conversion element 21 converts the image data into an electric signal and transfers the electric signal to the image forming unit 3.

The document feeding unit A3 includes a paper feed tray 23, a paper feed path 24, and a paper discharge tray 25, and conveys the documents placed on the paper feed tray 23 one by one along the paper feed path 24. Then, the paper is passed over the second platen 19 and discharged to the paper discharge tray 25. When reading a document fed from the document feeding unit A3 and passing on the second platen 19, the reading carriage 20 is stopped in advance below the second platen 19, and the reading platen 20 is placed on the second platen 19. Image data is generated from the image passing through.

[Post-processing device]
The post-processing apparatus C is connected to the further downstream side of the folding processing apparatus B connected to the image forming apparatus A, and is subjected to the folding processing by the folding processing apparatus B or discharged without being subjected to the folding processing. The sheet S is received, and staple processing, alignment processing, and the like are performed as necessary.

A post-processing path 26 is provided inside the post-processing apparatus C, and post-processing devices (not shown) such as a staple unit and an alignment unit are arranged along the post-processing path 26. The post-processing apparatus C receives the sheet S discharged from the image forming apparatus A via the folding processing apparatus B, and if necessary, performs a stapling process on the received sheet S by a post-processing apparatus such as a stapling unit or an aligning unit. The sheet S is discharged and stored in the storage tray 27 after performing the alignment process and the like.

[Folding device]
The folding processing apparatus B connected to the image forming apparatus A is an apparatus that receives the image-formed sheet S discharged from the sheet discharge port 16 of the image forming apparatus A and performs a folding process.

FIG. 2 shows the internal configuration of the folding device B. The folding processing apparatus B includes a control unit 140 that controls the operation of the folding processing apparatus B. Inside the folding processing apparatus B, a transport path 101 that extends in a substantially horizontal direction is provided. On the conveying path 101, one or a plurality of conveying roller pairs 102, a sheet basis weight detection sensor 141 that is a sheet basis weight recognizing unit, and a folding processing mechanism 103 arranged on the downstream side of the conveying roller pair 102 are provided. An additional folding unit 104 corresponding to the sheet pressing device according to the present invention is further provided at the end of the conveying path 101 on the downstream side of the folding processing mechanism 103. In the folding processing apparatus B, the sheet S transported along the transport path 101 is subjected to the folding processing by the folding processing mechanism 103, and then subjected to the additional folding processing by the additional folding unit 104 to perform the folding processing and the additional folding processing. The sheet S can be delivered to the post-processing apparatus C.

As shown in FIG. 1, the conveyance path 101 is arranged so as to be continuous with the paper ejection port 16 of the image forming apparatus A, and the sheet S ejected from the paper ejection port 16 is conveyed via the conveyance path 101. It can be loaded into the folding device B. Further, the discharge port of the additional folding unit 104 is also arranged so as to be continuous with the post-processing path 26 of the post-processing apparatus C, and the sheet S discharged from the additional folding unit 104 enters the post-processing apparatus C via the post-processing path 26. You can carry it in.

The conveying roller pair 102 is formed of a rubber roller, and includes an upper conveying roller 102a arranged on the upper side and a lower conveying roller 102b arranged on the lower side so as to face the upper conveying roller 102a. In the present embodiment, the upper transport roller 102a is connected to a transport roller drive motor (not shown) and is configured to rotate with the rotation of the transport roller drive motor, while the lower roller 102b is shown. It is pressed against the upper conveying roller 102a by the urging force of a spring that is not driven, and is rotated following it. However, the conveying roller pair 102 is not limited to the above-described configuration as long as it can convey the sheet S, and an appropriate configuration can be adopted.

The sheet basis weight detection sensor 141, which is a sheet basis weight recognizing unit, acquires information about the basis weight of the sheet S conveyed on the conveyance path 101 by, for example, ultrasonic waves, and controls the acquired information about the basis weight of the sheet S. It is transmitted to the section 140 and used in the additional folding process in the additional folding unit 104 as described later. Since the sheet basis weight detection sensor 141 is a known technique, a detailed description of the measurement principle and structure will be omitted here. In the present embodiment, the sheet basis weight detection sensor 141 is used as the sheet basis weight recognition unit, but the sheet basis weight detection sensor 141 may be any information as long as it can acquire information about the basis weight of the sheet S, and is not limited thereto. For example, as the sheet basis weight recognition means, a data storage section that stores information about basis weights corresponding to various sheet types is used, and from the information such as the type of the sheet S selected by the operator when using the image forming system. Information regarding the basis weight of the sheet S may be provided to the control unit 140.

The folding processing mechanism 103 includes a folding roller pair 105 and a thrust plate 107. The folding roller pair 105 is formed of a rubber roller, and includes an upper folding roller 105a arranged on the upper side and a lower folding roller 105b arranged on the lower side so as to face the upper folding roller 105a. The lower folding roller 105b is pressed against the upper folding roller 105a by the urging force of a spring (not shown), and the upper folding roller 105a and the lower folding roller 105b are connected to a common folding roller drive motor (not shown). They are connected to each other and rotate in the opposite directions to each other as the folding roller drive motor rotates. The veneer plate 107 is arranged between the conveying roller pair 102 and the folding roller pair 105, and is connected to a veneer plate drive motor (not shown). It is designed to move parallel to the side transport path.

An upper transport guide 108, a lower transport guide 109, an upper folding guide 110, and a lower folding guide 111 are provided on the transport path 101 between the transport roller pair 102 and the folding roller pair 105.

The upper conveyance guide 108 is formed right after the conveyance roller pair 102 to above the ejection plate 107 so as to guide the leading end of the sheet S from the conveyance roller pair 102 to the ejection plate 107. The upper conveyance guide 108 is for regulating the flow of the sheet S conveyed on the conveyance path 101, is arranged on the upper side of the conveyance path 101, and has a shape bent downward toward the downstream side. .. The upper folding guide 110 is disposed between the upper conveyance guide 108 and the folding roller pair 105, and the upper folding guide 110 of the folding roller pair 105 guides the leading end of the sheet S and a folded portion of the sheet S described later to the folding roller pair 105. It extends to the last minute. The upper folding guide 110 is for regulating the flow of the sheet S in the folding processing mechanism 103, and is provided on the downstream side of the upper transport guide 108 and above the transport path 101.

The lower conveyance guide 109 is provided to regulate the flow of the sheet S conveyed on the conveyance path 101, is arranged on the lower side of the conveyance path 101, and as the upper conveyance guide 108 moves toward the downstream side. The shape is bent downward. The lower conveyance guide 109 is interrupted before the veneer 107, and an open space is formed on the downstream side of the lower conveyance guide 109. The lower folding guide 111 is arranged on the downstream side of the thrust plate 107, extends over the upstream side and the downstream side of the folding roller pair 105, and is located on the upstream side of the folding roller pair 105 in the lower folding guide 111. The portion has a horizontal surface for guiding the leading end of the conveyed sheet S and a bent portion of the sheet S described later to the nip portion of the folding roller pair 105 and an inclined surface for facilitating the guiding to the horizontal surface.

The veneer 107 is horizontally moved by a veneer driving device (not shown) and a control unit 140. Further, when the sheet S is conveyed to the folding roller pair 105 by the conveyance roller pair 102 along the conveyance path 101, the thrust plate 107 fills the space between the lower conveyance guide 109 and the lower folding guide 111. The leading edge of the conveyed sheet S is guided to the lower folding guide 111. The folding processing operation by the projecting plate 107 will be described later.

Next, the configuration of the additional folding unit 104 will be described with reference to FIG. The additional folding unit 104 is arranged above the lower folding guide 111 on the downstream side of the pair of folding rollers 105 in the sheet S transport direction. The additional folding unit 104 includes a movable support member 112, a plurality of additional folding rollers 114 supported by the support member 112, a restricting member 115 attached to the support member 112, and a lower folding guide for the support member 112. A first moving mechanism 116 that moves in a direction toward and away from 111 and a second moving mechanism 117 that horizontally moves the support member 112 along the fold line of the sheet S are provided. Portions of the upper folding guide 110 and the lower folding guide 111, which are vertically opposed to each other, downstream of the folding roller pair 105 function as a pair of carry-in guides 118 that guide the sheet S into the additional folding unit 104. The upstream ends of the pair of carry-in guides 118 form the carry-in port 119 of the additional folding unit 104. Further, the additional folding portion is constituted by the plurality of additional folding rollers 114 and the lower folding guide 111 which are supported by the support member 112 as described above.

Each of the plurality of additional folding rollers 114 is pressed so that each additional folding roller 114 can rotate about a rotation axis extending in the conveyance direction of the sheet S (direction parallel to the upper surface of the lower folding guide 111 and perpendicular to the fold line of the sheet S). The support members 112 are arranged in the member arrangement area along the direction of the folds of the sheet S so as to be spaced apart from each other at regular intervals. In addition, the first moving mechanism 116 moves the support member 112 that supports the plurality of additional folding rollers 114 in a direction in which the supporting member 112 approaches and separates from the lower folding guide 111. As a result, the plurality of additional folding rollers 114 are moved toward and away from the lower folding guide 111, and the fold line of the sheet S arranged between each additional folding roller 114 and the lower folding guide 111 is added to each additional folding roller 114. The lower folding guide 111 and the lower folding guide 111 can move between a pressing position and a retracted position in which a plurality of additional folding rollers 114 are moved from the pressing position in a direction away from the sheet S. Further, the second moving mechanism 117 can move the plurality of additional folding rollers 114 along the fold line of the sheet S by moving the support member 112 in the horizontal direction (left and right direction in FIG. 3) at the pressing position. ing. The plurality of additional folding rollers 114 and the lower folding guide 111 are in direct contact with each other at the pressing position unless the sheet S is interposed between them. The length of the pressing member disposition area (that is, the distance between the additional folding rollers 114 disposed at both extreme positions of the pressing member disposition area) is adjacent to one of the extreme positions when moved from the retracted position to the pressed position. The additional folding roller in which one end of the fold of the sheet S (the upstream end in the moving direction of the additional folding roller 114) is disposed between the two additional folding rollers 114 and the other extreme position. 114 is arranged to be placed on the fold line. Preferably, as in the illustrated embodiment, the length of the pressing member arrangement region, that is, the length between the additional folding rollers 114 arranged at both extreme positions of the pressing member arrangement region is carried into the additional folding unit 104. It is shorter than the length of the fold of the sheet S by one pitch of the array of the plurality of additional folding rollers 114 (one interval between two additional folding rollers arranged adjacent to each other). In this case, the number of additional folding rollers 114 required can be reduced, and the cost of the additional folding rollers 114 can be reduced. Further, since the number of the additional folding rollers 114 supported by the supporting member 112 decreases, the pressing force per one additional folding roller 114 against the sheet S increases when the same force is applied to the supporting member 112, and The effect of folding is enhanced, and it is possible to efficiently perform additional folding with a smaller force.

In the additional folding unit 104, the plurality of additional folding rollers 114 are arranged in the retracted position with respect to the lower folding guide 111 or in the receiving position farther to the retracted position side than the pressed position, and the sheets are placed in the additional folding unit 104. Accept S. After that, the position of the sheet S is detected by the sheet position detecting means (not shown) provided on the upstream side of the pair of folding rollers 105, and when the fold of the sheet S is increased and the sheet S is reached below the folding roller 114, the sheet S is removed. Then, the plurality of additional folding rollers 114 are moved to the pressing position with respect to the lower folding guide 111 by the first moving mechanism 116. In the sheet S, when the plurality of additional folding rollers 114 move to the pressing position, one end of the fold (upstream end in the direction of movement along the fold) is located at one extreme position in the pressing member arrangement area. On the other hand, the other end of the fold (the end on the downstream side in the direction of movement along the fold) is located between the two additional folding rollers 114, outside the pressing member arranging region (that is, the pressing member arranging region). Is placed in the additional folding unit 104 so as to be disposed on the other extreme position of the additional folding roller 114). Further, by moving the plurality of additional folding rollers 114 along the folds of the sheet S with respect to the lower folding guide 111 at the pressing position by the second moving mechanism 117, the folds of the sheet S are folded by the plurality of additional folding rollers 114. Is pressed over the entire area of the fold to perform additional folds and strengthen the fold. In this way, the additional nuclear folding roller 114 and the lower folding guide 111 function as a pressing member.

Further, a restricting member 115 having a substantially L-shaped cross section attached to the support member 112 is arranged outside the additional folding rollers 114 at both extreme positions and between the adjacent additional spaced folding rollers 114. The restricting member 115 moves the additional folding roller 114 with respect to the lower folding guide 111 along the fold line of the sheet S at the pressing position to perform the additional folding, and the bottom surface of the restricting member 115 (that is, The distance d1 between the surface facing the lower folding guide 111) and the upper surface of the lower folding guide 111 forms the height of a normal transport path, for example, a carry-in path continuing to the carry-in entrance 119 of the additional folding unit 104. It is arranged at a regulation position shorter than the distance d2 between the pair of carry-in guides 118 (the upper carry-in guide 118a and the lower carry-in guide 118b), and moves along with the fold line of the sheet S together with the support member 112 while keeping the distance d1. .. The distance d1 between the bottom surface of the regulation member 115 and the top surface of the lower folding guide 111 is determined so that these members do not come into direct contact with each other. As a result, before the pressing by the additional folding roller 114, the restricting member 115 pushes down the height of the fold to be lower than between the upper loading guide 118a and the lower loading guide 118b, and the additional folding roller 114 presses the sheet S. The additional fold can be performed by pressing the fold line.

The gap between the additional folding rollers 114 and the lower folding guide 111 and the gap between the regulating member 115 and the lower folding guide 111 are kept constant over the entire area in the direction along the fold of the sheet S. Is dripping

As shown in FIG. 4, each of the additional folding rollers 114 is rotatably attached to an auxiliary member 113 that is movably supported with respect to the support member 112, and is formed on the support member 112. It is preferable that the spring 121 be arranged as an elastic member between the spring receiving portion 120 and the upper end portion of each auxiliary member 113 so as to urge the additional folding roller 114 toward the lower folding guide 111. .. With such a configuration, when the supporting member 112 of the additional folding unit 104 and the regulating member 115 attached thereto move downward toward the lower folding guide 111, the additional folding roller 114 moves the sheet S. When it comes into contact with the lower folding guide 111 through the above, the downward movement is stopped. On the other hand, the contraction of the spring 121 allows the support member 112 and the regulating member 115 to continue moving further downward, and the distance between the bottom surface of the regulating member 115 and the upper surface of the lower folding guide 111 reaches a desired value. It becomes possible to stop when the regulating member 115 reaches the regulating position. Further, if each auxiliary member 113 is biased by the individual spring 121, even if the support member 112 tilts a little and moves along the fold line of the sheet S, the additional folding rollers 114 move with respect to the fold line of the sheet S. As a result, a constant pressing force can be applied, and the pressing force changes depending on the fold line, and it is possible to suppress uneven uneven folding. Further, the additional folding roller 114 is pressed against the sheet S by the compression of the spring 121, and the pressing force can be surely applied to the fold of the sheet S.

Next, detailed configurations of the first moving mechanism 116 and the second moving mechanism 117 in the illustrated embodiment will be described.

The support member 112 of the additional folding unit 104 is attached to a slider 124 movable along a guide rail 123 fixed to a casing 122 of the folding device B and the like so as to be vertically movable via a bracket 125, It is adapted to move in the horizontal direction in conjunction with the slider 124. A rack 127 that meshes with a pinion (not shown) that rotates integrally with the pulley 126 is provided on the slider 124. The additional folding drive motor 128 is driven to rotate the pulley 127 via a belt 129. By transmitting it to 126 and rotating the pulley 126, the slider 124 can be moved horizontally along the guide rail 123.

In addition, the support member 112 is formed with a cam groove 131 that engages with a contact 130 fixed to the housing 122 of the folding apparatus B or the like. With the horizontal movement of the support member 112, the cam groove 131 moves while engaging with the contact 130, and the support member 112 moves according to the shape of the cam groove 131 while being guided. The cam groove 131 has a first bottom horizontal portion extending in a substantially horizontal direction, a first inclined portion extending obliquely upward from the end of the first portion, and a substantially horizontal direction extending from the end of the first inclined portion. It includes a top horizontal portion that extends, a second sloped portion that slopes downwardly from the end of the top horizontal portion, and a second bottom horizontal portion that extends substantially horizontally from the end of the second sloped portion. While the first inclined portion and the second inclined portion of the cam groove 131 are engaged with the contact 130, the slider 124 moves the support member 112 relative to the housing 122 in the horizontal direction in FIG. The member 112 moves toward and away from the lower folding guide 111, that is, in the vertical direction in FIG. As described above, the guide rail 123, the slider 124, the bracket 125, the pulley 126, the rack 127, the additional folding drive motor 128, the belt 129, the contact 130, and the first and second inclined portions of the cam groove 131 are the first and second inclined portions. The first moving mechanism 116 is configured. Further, the support member 112 is supported by the support member 112 by moving the support member 112 in the horizontal direction in the figure with respect to the housing 122 by the slider 124 while engaging the top horizontal portion of the cam groove 131 with the contact 130. The plurality of additional folding rollers 114 move in the horizontal direction in FIG. 3 along the fold line of the sheet S with respect to the lower folding guide 111. In this manner, the guide rail 123, the slider 124, the bracket 125, the pulley 126, the rack 127, the additional folding drive motor 128, the belt 129, the contact 130, and the top horizontal portion of the cam groove 131 constitute the second moving mechanism 117. ing. In the illustrated embodiment, the contact 130 is fixed to the housing 122 and the cam groove 131 is formed in the support member 112, but the contact 130 is fixed to the support member 112 and the cam groove 131 is formed in the housing. It goes without saying that it may be formed on the body 122.

When a plurality of additional folding rollers 114 are arranged at regular intervals as in the illustrated embodiment, all of the folds located between the adjacent additional folding rollers 114 are subjected to additional folding rollers. In order to press between the lower folding guide 111 and the lower folding guide 111, a plurality of additions are made to the lower folding guide 111 at the pressing position by the distance between adjacent additional folding rollers 114 (that is, a distance of one pitch) or more. It is necessary to move the folding roller 114 along the fold line. In the above-described configuration of the first moving mechanism 116, the slider 124 is moved in the horizontal direction while the contactor 130 and the first inclined portion of the cam groove 131 are engaged with each other. The additional folding roller 114 approaches the lower folding guide 111 and is moved to the pressing position. Further, in the above-described configuration of the second moving mechanism 117, the slider 124 is moved in the horizontal direction while engaging the contactor 130 and the horizontal portion of the top of the cam groove 131. The additional folding roller 114 moves along the fold line at the pressing position. Therefore, the horizontal length (direction along the fold) of the top horizontal portion of the cam groove 131 is equal to or longer than one pitch of the adjacent additional folding rollers 114.

During the additional folding process, the control unit 140 does not interpose the sheet portion (the portion where the sheet S is divided by the fold) between the additional folding roller 114 and the fold, and the additional folding roller 114 directly faces the fold. When contacting, the plurality of additional folding rollers 114 arranged at the pressing position by the first moving mechanism 116 are set at a predetermined speed regardless of the information about the basis weight of the sheet S acquired by the sheet basis weight recognition unit. The second moving mechanism 117 is controlled to move along the fold line at V1. Here, in order to simplify the control, the speed at which the additional folding roller 114 is moved along the first folding line 132 with respect to the lower folding guide 111 at the pressing position is obtained by the sheet basis weight recognition unit. Although the speed V1 is the same regardless of the information about the basis weight of S, the speed may be switched depending on whether the basis weight of the sheet S is equal to or greater than a predetermined threshold value α. On the other hand, the control unit 140, based on the information about the grammage of the sheet S acquired by the sheet grammage recognizing unit when the sheet portion is interposed between the additional fold roller 114 and the fold during the additional fold processing. Then, the second moving mechanism is controlled so as to change the speed at which the plurality of additional folding rollers 114 arranged at the pressing position by the first moving mechanism 116 are moved along the fold, and the plurality of additional folding rollers 114 are controlled. The time for applying the pressing force to the fold between the lower folding guide 111 and the lower folding guide 111 is changed. Specifically, when the additional fold processing is performed, the control unit 140 determines that the basis weight of the sheet S detected by the sheet basis weight detection sensor 141, which is a sheet basis weight recognizing unit, is equal to or larger than a predetermined threshold value α. When the sheet portion is interposed between the additional folding roller 114 and the fold, the plurality of additional folding rollers 114 arranged at the pressing position are moved along the fold at a speed V2 slower than the speed V1 to obtain the sheet basis weight. When the basis weight of the sheet S detected by the sheet basis weight detection sensor 141 which is a recognition unit is smaller than a predetermined threshold value α, when the sheet portion is interposed between the additional folding roller 114 and the fold, The second moving mechanism is controlled so as to move the plurality of additional folding rollers 114 arranged at the pressing position along the fold line at V3 which is faster than the speed V2. The speed V3 may be higher than the speed V2, but is preferably higher than the speed V1.

When the additional folding roller 114 arranged at the pressing position is moved along the fold at a speed V2 lower than the speed V1, a pressing force is applied to the fold between the plurality of additional folding rollers 114 and the lower folding guide 111. Since the time required for the operation is longer, the total amount (working amount) of the pressing force applied between the additional folding roller 114 and the lower folding guide 111 is larger than that at the speed V1. On the other hand, when the additional folding roller 114 arranged at the pressing position is moved along the fold line at a speed V3 higher than the speed V2 (preferably the speed V1), the plurality of additional folding rollers 114 and the lower folding guide 111 are separated from each other. Since the time for applying the pressing force to the folds becomes shorter, the sheet portion and the folds are applied between the additional folding roller 114 and the lower folding guide 111 as compared with the case of the speed V2 (preferably the speed V1). The total amount of pressing force (work load) is reduced. When the sheet portion is interposed between the additional folding roller 114 and the fold, the sheet portion disperses the pressing force to reduce the pressing force applied to the fold, but the sheet is placed at the pressing position at a speed V2 slower than the speed V1. If the additional folding roller 114 is moved along the fold, the additional folding roller 114 cancels the influence of the decrease in the pressing force applied to the fold due to the sheet portion interposed between the additional folding roller 114 and the fold. Since the total amount of pressing force (work amount) applied to the sheet portion and the fold between 114 and the lower folding guide 111 increases, when the sheet portion is interposed between the additional folding roller 114 and the fold, the fold It is possible to prevent the total amount of pressing force applied from becoming smaller than the total amount of pressing force applied when the additional folding roller 114 and the fold are directly contacted. If the additional folding roller 114 arranged at the pressing position is moved along the fold line at a speed V3 faster than the speed V2, the pressing force applied to the fold between the additional folding roller 114 and the lower folding guide 111. Since the total amount of the folds is reduced, even in the case of a sheet having a small grammage and easy to have a crease, even if the fold line is pressed with the sheet part interposed between the additional folding roller 114 and the fold line, the crease marks on the sheet part Can be prevented from remaining as a line. In particular, if the speed V3 is set to be faster than the speed V1, the pressing applied to the fold between the additional folding roller 114 and the lower folding guide 111 is more than the case where the additional folding roller 114 directly contacts and presses the fold. Since the total amount of pressure is reduced, it is possible to further enhance the effect of suppressing the traces of folds left as streaks in the sheet portion. Therefore, the variation of the effect of the additional fold due to the positional relationship between the additional fold roller 114, the fold, and the sheet portion is suppressed, and it becomes possible to realize the fold having a more uniform fold height, and the sheet after the additional fold processing is performed. It is possible to improve the quality of S.

Next, the operations of the folding processing apparatus B and the additional folding unit 104 of the illustrated embodiment will be described in detail with reference to FIGS. 5 to 9. Here, the folding process is performed by the folding mechanism 103 as described above, and the sheet is divided into three sheet portions by the first fold 132 and the second fold 133, which are shown in FIGS. 8 and 9. As described above, the sheet S folded in the Z shape so that the first fold line 132 is located above the sheet portion and the second fold line 133 is located below the sheet portion is carried into the additional folding unit 104. In addition, a sheet of thin paper as the sheet S having a small grammage and a sheet of thick paper or plain paper as the sheet S having a large grammage are carried into the additional folding unit 104.

In the folding device B, first, the folding mechanism 103 performs a folding process on the sheet S so that the first folds 132 are located above the sheet portion and the second folds 133 are located below the sheet portion. Then, the sheet S is folded into a Z shape (step S1). Specifically, when it is recognized that the leading edge of the sheet S is nipped by the folding roller pair 105, the control unit 140 controls the folding processing mechanism 103 to move the veneer 107 in the horizontal direction in order to form a folded portion. The space is moved to a retracted position below the lower conveyance guide 109 to form a space for loop formation between the lower conveyance guide 109 and the lower folding guide 111. After the space for loop formation is formed, when the sheet S is conveyed by a predetermined amount in a state where the front end of the sheet S is nipped by the pair of folding rollers 105, the intermediate portion of the sheet S bends downward in the space for loop formation. Then create the loop part. In this state, the pushing plate 107 is moved in the horizontal direction from the retracted position toward the folding roller pair 105 to form a bent portion, and after the pushing plate 107 reaches before the folding roller pair 105, the folding roller pair 105 is moved. By driving the sheet S to convey the sheet S, the first fold line 132 is formed, and further, the sheet S is conveyed by the folding roller pair 105 after moving the pushing plate 107 to the retracted position to nips the loop portion. Thus, the second fold 133 is formed, and the Z-folded sheet S is conveyed to the downstream side of the folding processing mechanism 103.

The sheet S folded by the folding mechanism 103 is carried into the additional folding unit 104 by the folding roller pair 105 through the carry-in port 119 (step S2). When the sheet S from the folding processing mechanism 103 is received in the additional folding unit 104 through the carry-in port 119 and the carry-in path constituted by the upper carry-in guide 118a and the lower carry-in guide 118b, the additional fold unit 104 is configured as shown in FIG. 8) and FIG. 8A, the plurality of additional folding rollers 114 supported by the support member 112 are arranged at the receiving position which is the home position. At this time, the lower ends of the plurality of additional folding rollers 114 supported by the support member 112 regulate the upper side of the carry-in path, and the lower folding guide 111 regulates the lower side of the carry-in path, so that the sheet S to be carried in is conveyed. The first fold line 132 functions as a guide for guiding the first fold line 132 between the additional folding roller 114 and the lower folding guide 111. At this time, the contact 130 is located at the end of the first bottom horizontal portion of the cam groove 131. In the illustrated embodiment, the second retracted position described later is the receiving position. However, if the additional folding roller 114 and the lower folding guide 111 are located apart from the pressing position on the retracted position (first retracted position or second retracted position) side, the accepting position will be changed. It may be set at a position different from the second retracted position.

The control unit 140, based on the position of the sheet S detected by the sheet position detection means (not shown) provided on the upstream side of the folding roller pair 105, as shown in FIG. The sheet S is stopped when it is recognized that the first fold 132 on the leading end side of the sheet S carried in from the folding roller pair 105 to the carry-in port 119 has reached below the additional folding portion, that is, the additional folding roller 114. (Step S3).

When the first fold line 132 stops at the additional fold portion, the control unit 140 drives the additional fold drive motor 128 to cause the support member together with the slider 124 via the pinion and the rack 127 that rotate integrally with the pulley 126. 112 is moved horizontally. As a result, the portion where the contact 130 engages with the cam groove 131 moves from the first bottom horizontal portion to the first inclined portion, and the support member 112 descends toward the lower folding guide 111 accordingly. As shown in FIGS. 6B and 8B, the plurality of additional folding rollers 114 supported by the support member 112 are arranged between the lower folding guide 111 and the first folding sheet 111. The fold line 132 is moved to a pressing position where the fold line 132 is sandwiched and pressed. At this time, one end of the first fold line 132 of the sheet S (an upstream end in the moving direction of the additional fold roller 114 on the outward path) of two adjacent additional fold rollers 114 arranged at one extreme position. The additional pressing roller 114, which is disposed between the two and is located at the other extreme position, is placed on the first fold line 132 of the sheet S, and the other end portion (forward path) of the first fold line 132 of the sheet S. The downstream side end of the additional folding roller 114 in the moving direction) is arranged outside the pressing member arrangement area (see FIG. 6B). In FIG. 6B, one end of the first fold line 132 of the sheet S is shown to be arranged at an intermediate position between two adjacent additional folding rollers 114 arranged at the extreme position. In the above-mentioned “between two adjacent additional folding rollers 114 arranged at the extreme position”, the pressing point of the additional folding roller 114 arranged at the extreme position is at one end of the first fold 132 of the sheet S. Positions that match the part are also included. Further, since the auxiliary member 113 to which the additional folding roller 114 is attached is urged toward the lower folding guide 111 by the spring 121, the support member 112 descends, and the additional folding roller 114 passes through the sheet S. The support member 112 can be further lowered even after contacting the lower folding guide 111. Along with this, the regulating member 115 further descends to press the first fold line 132 of the sheet S positioned below the additional folding roller 114, and the thickness of the fold line of the sheet S becomes equal to or smaller than a predetermined thickness. Regulate. Further, each additional folding roller 114 presses the first fold line 132 of the sheet S toward the lower folding guide 111 by the bias of the spring 121. Note that the carrying-in direction in this specification means the direction in which the sheet S is carried into the additional folding unit 104 from the folding roller pair 105 through the carry-in port 119.

When the plurality of additional folding rollers 114 move to the pressing position, the controller 140 drives the additional folding drive motor 128 from the state shown in FIGS. 6B and 8B to support the slider 124 and the supporting member. 112 is further moved in the horizontal direction to move the position where the contact 130 engages with the cam groove 131 from the first inclined portion to the top horizontal portion, as shown in FIG. 6C. Then, the regulation member 115 attached to the support member 112 regulates the thickness of the first fold line 132 of the sheet S to be equal to or less than a predetermined thickness (corresponding to the distance d1) and is supported by the support member 112. The additional folding roller 114 moves at a pressing position along the first folding line 132 of the sheet S with respect to the lower folding guide 111 by a distance equal to or more than one pitch of the plurality of additional folding rollers 114, and moves in the moving direction. The additional folding roller 114 moves to the other end of the first fold 132 of the sheet S (downstream end in the moving direction of the additional folding roller 114 in the forward path). In this way, the first folding line 132 is pressed over the entire area by the additional folding roller 114 and the lower folding guide 111, and the first folding line 132 is strengthened, that is, the additional folding is performed.

The control unit 140 determines whether the additional folding roller 114 can directly contact the fold when moving the additional folding roller 114 along the fold at the pressing position as described above, that is, between the additional folding roller 114 and the fold. The operation of the second moving mechanism 117 is controlled based on whether or not the sheet portion is present in the sheet, and the speed at which the additional folding roller 114 is moved along the fold is changed (step S4).

When the fold line is located above the sheet portion and the additional folding roller 114 can directly contact the fold line, such as the first fold line 132 on the leading side of the sheet S in the transport direction, the control unit 140 causes the second moving mechanism. By controlling the operation of 117, the first fold 132 with respect to the lower folding guide 111 at the pressing position regardless of the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 that is the sheet basis weight recognition unit. The additional folding roller 114 is moved at a predetermined speed V1 along with (step S5). In order to simplify the control, the speed at which the additional folding roller 114 is moved along the first folding line 132 with respect to the lower folding guide 111 at the pressing position is determined by the sheet basis weight of the sheet S acquired by the sheet basis weight recognition unit. It is preferable to set the same speed V1 regardless of the information about the amount, but the speed may be switched depending on whether the basis weight of the sheet S is a predetermined threshold value α or more.

When the pressing on the first fold line 132 is completed, the control unit 140 drives the additional folding drive motor 128 from the state shown in FIGS. 6C and 8C to move the support member 112 together with the slider 124. Further, it is moved in the horizontal direction to move the position where the contact 130 engages with the cam groove 131 from the top horizontal portion to the second bottom horizontal portion via the second inclined portion. As a result, as shown in FIGS. 6D and 8D, the support member 112 ascends together with the restriction member 115 in the direction away from the lower folding guide 111, and a plurality of additional members supported by the support member 112 are provided. The folding roller 114 moves to the retracted position, and the first additional folding process is completed. The first retracted position is a position different from the receiving position which is the home position. When the first additional folding process is completed and the state shown in FIGS. 6D and 8D is reached, the sheet S can be transported from the additional folding portion, and the sheet S is positioned on the upstream side in the carry-in direction. The sheet S is conveyed downstream by the conveying roller pair 102 and the folding roller pair 105 (step S6).

Similar to the case of the first fold line 132, the sheet S that has undergone the first additional folding process with respect to the first fold line 132 is conveyed, and the sheet position detection unit (upper side of the folding roller pair 105 ( When the controller 140 recognizes that the second fold 133 has reached the additional fold based on the position of the sheet S detected by (not shown), the controller 140 determines as shown in FIG. The sheet S is stopped when the second fold 133 of the sheet S reaches below the additional folding portion, that is, the additional folding roller 114 (step S3).

When the second fold 133 is stopped at the additional folding section, the control section 140 drives the additional folding drive motor 128 so as to rotate in a direction opposite to the forward path, thereby rotating the pinion and the rack together with the pulley 126. The support member 112 together with the slider 124 is moved in the horizontal direction via 127 in the direction opposite to that of the forward path. As a result, the position where the contact 130 engages with the cam groove 131 moves from the second bottom horizontal portion to the second inclined portion, and the support member 112 descends toward the lower folding guide 111 accordingly. As shown in FIGS. 7F and 9F, the plurality of additional folding rollers 114 supported by the supporting member 112 are arranged between the lower folding guide 111 and the second folding guide 111. The fold line 133 is moved to a pressing position where the fold line 133 is sandwiched and pressed. The positions of the plurality of additional folding rollers 114 at this time, that is, the position of the starting point of the return path is the same as the position of the ending point of the outward path. Further, at this time, one end of the second fold line 133 of the sheet S (an upstream end in the moving direction of the additional fold roller 114 on the return path) is located at one extreme position and is adjacent to the two additional fold rollers. The additional folding roller 114, which is disposed between 114 and at the other extreme position, is placed on the second fold 133 of the sheet, and the other end portion of the second fold 133 of the sheet S ( The downstream side end in the moving direction of the additional folding roller 114 on the return path is arranged outside the pressing member arrangement area (see FIG. 7(f)). Further, since the auxiliary member 113 to which the additional folding roller 114 is attached is urged toward the lower folding guide 111 by the spring 121, the support member 112 descends, and the additional folding roller 114 passes through the sheet S. The support member 112 can be further lowered even after contacting the lower folding guide 111. Along with this, the regulating member 115 further descends to press the sheet portion of the sheet S located below the additional folding roller 114 and the second fold line 133, and the sheet of the sheet S to a predetermined thickness or less. The thickness of the portion and the second fold 133 is regulated. Further, each additional folding roller 114 presses the sheet portion of the sheet S and the second fold 132 toward the lower folding guide 111 by the bias of the spring 121.

When the plurality of additional folding rollers 114 move to the pressing position, the control unit 140 drives the additional folding drive motor 128 from the state shown in FIGS. 7F and 9F to support the slider 112 and the support member 112. 7 is further moved horizontally in the direction opposite to the outward path, and as shown in FIG. 7(g), the position where the contact 130 engages with the cam groove 131 is changed from the second inclined portion to the top horizontal portion. To move. Then, the thickness of the sheet portion of the sheet S located below the additional folding roller 114 and the second fold 133 by the regulating member 115 attached to the support member 112 is a predetermined thickness (corresponding to the distance d1). While restricting to the following, the plurality of additional folding rollers 114 supported by the support member 112 at the pressing position along the second fold 133 of the sheet S with respect to the lower folding guide 111 are provided with a plurality of additional folding rollers 114 in a direction opposite to the outward path. The additional folding roller 114 is moved by a distance equal to or more than one pitch of the folding roller 114 so that the leading additional folding roller 114 in the moving direction is at the other end of the second fold 133 of the sheet S (downstream in the moving direction of the additional folding roller 114 in the return path). Move over the side edge). In this manner, the additional folding roller 114 and the lower folding guide 111 press the entire area of the second fold 133 to strengthen or strengthen the second fold 133.

As in the case of the first fold line 132, the control unit 140 moves the additional fold roller 114 along the second fold line 133 at the pressing position and determines whether the additional fold roller 114 can directly contact the fold line. That is, the speed of moving the additional folding roller 114 along the fold line is changed by controlling the operation of the second moving mechanism 117 based on whether the sheet portion is interposed between the additional folding roller 114 and the fold line. Yes (step S4). Further, the control unit 140 has a fold located below the sheet portion, such as the second fold 133 on the trailing end side of the sheet S in the transport direction, and the sheet portion is interposed between the additional folding roller 114 and the fold. In doing so, the operation of the second moving mechanism 117 is controlled according to the basis weight of the sheet S acquired by the sheet basis weight recognition means, and the plurality of additional folding rollers 114 are moved along the second folds 133. After changing the speed to be applied from the speed V1, the second folding line 133 is subjected to the additional folding process (step S7).

When the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is equal to or larger than a predetermined threshold value α (for example, when the conveyed sheet S is plain paper or thick paper), the control unit 140 causes the additional folding roller 114. When the sheet portion is interposed between the second folding mechanism 133 and the second folding mechanism 133, the second moving mechanism 117 supports the lower folding guide 111 on the supporting member 112 along the second folding mechanism 133 at the pressing position. The additional folding rollers 114 are moved at a speed V2 slower than the speed V1 to perform the additional folding process on the second fold 133 (step S8).

When the sheet portion is interposed between the additional folding roller 114 and the fold, the sheet portion disperses the pressing force to reduce the pressing force applied to the fold, but the sheet is placed at the pressing position at a speed V2 slower than the speed V1. By moving the additional folding roller 114 along the second fold 133, the total amount of pressing force applied to the sheet portion and the second fold 133 between the additional folding roller 114 and the lower folding guide 111 (work Amount) will increase. Therefore, when the sheet portion is interposed between the additional folding roller 114 and the second folding line 133, the total amount of the pressing force applied to the second folding line 133 causes the additional folding roller 114 and the first folding line 132 to move. It is possible to suppress a decrease in the total amount of pressing force applied when making direct contact, and to suppress fluctuations in the effect of additional folding due to the positional relationship between the additional folding roller 114, the fold 133, and the sheet portion. Thus, it becomes possible to realize a fold line having a more uniform fold height.

On the other hand, when the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is smaller than a predetermined threshold value α (for example, when the conveyed sheet S is thin paper), the control unit 140 causes the additional folding roller 114. When the sheet portion is interposed between the second folding mechanism 133 and the second folding mechanism 133, the second moving mechanism 117 supports the lower folding guide 111 on the supporting member 112 along the second folding mechanism 133 at the pressing position. The additional folding rollers 114 to be moved are moved at a speed V3 higher than the speed V2, and the additional folding processing is performed on the second fold 133 (step S9).

When the sheet portion is interposed between the additional folding roller 114 and the fold, a step due to the fold is generated between the lower folding guide 111 and the lower side of the sheet portion, and the basis weight is small and a crease is formed like thin paper. In the case of the easy sheet S, when the sheet portion and the folds are pressed between the additional folding roller 114 and the lower folding guide 111, the traces due to the folds tend to remain in the sheet portion as streaks. However, by moving the additional folding roller 114 arranged at the pressing position at a speed V3 faster than the speed V2 along the second fold 133, the additional folding roller 114 is increased more than in the case of a sheet having a large grammage and less likely to leave marks by the fold. The total amount of pressing force applied to the sheet portion and the second fold 133 between the folding roller 114 and the lower folding guide 111 is reduced. Therefore, in the case of the sheet S having a small grammage and a tendency to have a crease, even if the fold is pressed with the sheet portion interposed between the additional folding roller 114 and the second fold 133, the second portion is not applied to the sheet portion. It is possible to prevent the marks due to the fold line 133 from remaining as streaks, and it is possible to improve the quality of the sheet S after the additional folding process.

In this way, the control unit 140, when the sheet portion is interposed between the additional folding roller 114 and the fold, according to the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 that is the sheet basis weight identifying unit. By changing the speed at which the additional folding roller 114 is moved along the fold at the pressing position, it is possible to suppress the creases due to the folds from remaining on the sheet portion, and to strengthen the creases when the creases are hardly left. So that you can get enough.

In the illustrated embodiment, in the case of a sheet S such as thin paper having a small grammage and having a tendency to fold, a sheet portion is interposed between the additional folding roller 114 and the second folding line 133. It is described that the additional folding roller 114 moves along the second fold line 133 at a speed V3 faster than the speed V2 at which the additional folding roller 114 moves along the first fold line 132 at the pressed position. However, in order to make it easier to prevent a crease from being left on the sheet portion, in the case of a sheet S such as thin paper having a small grammage and having a tendency to fold easily, the additional folding roller 114 and the second fold 133 are When the sheet portion is interposed between the additional folding roller 114 and the additional folding roller 114, the additional folding roller 114 may be moved along the second fold 133 at a speed V3 higher than the speed V1 in the additional folding process.

In addition, when the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is equal to or larger than a predetermined threshold value α, as in the additional folding process for the second fold 133 in step S8, When the sheet portion is interposed between the plurality of additional folding rollers 114 and the folds to apply the pressing force to the folds between the plurality of additional folding rollers 114 and the lower folding guide 111, the additional folding rollers 114 are The operation of the second moving mechanism 117 may be controlled so as to increase the number of times of movement of the additional folding roller 114 along the second fold 133, as compared with the case of facing and directly contacting the second fold 133. .. Here, the unit number of movements along the fold means that the support member 112 moves along the fold of the sheet S, so that the entire region of the fold is additionally folded. Specifically, the location where the contact 130 and the cam groove 131 engage is a one-way stroke in which one end travels from one end to the other end of the top horizontal portion of the cam groove 131, or from the other end to one end. The number of times. As a result, the time for pressing the second fold 133 between the additional folding roller 114 and the lower folding guide 111 becomes longer, and the total amount (working amount) of the pressing force applied to the second fold 133 increases. Therefore, the effect of strengthening the second fold 133 can be enhanced. Therefore, when the grammage of the sheet S is equal to or larger than the predetermined threshold value α, such as plain paper or thick paper, and the marks due to the folds are hard to remain, the effect of the additional folds due to the positional relationship between the additional fold roller 114 and the folds and the sheet portion is obtained. It is possible to further suppress the variation and realize a fold having a more uniform fold height. When the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is smaller than a predetermined threshold value α, the control unit 140 forms a sheet between the additional folding roller 114 and the fold like the second fold 133. When the portion intervenes, the pressing force applied between the additional folding roller 114 and the lower folding guide 111 is weaker than when the additional folding roller 114 directly contacts the fold line. Thus, the first moving mechanism 116 may be controlled. As a result, the total amount of pressing force applied to the folds between the additional folding roller 114 and the lower folding guide 111 is further reduced, so that the basis weight is smaller than a predetermined threshold value like thin paper, and the crease is not generated. In the case of a sheet that is easy to attach, it is possible to further suppress the leaving of marks due to folds.

When the pressing on the second fold line 133 is finished, the additional folding drive motor 128 drives the slider 124 and the support member 112 in the direction opposite to the outward direction from the state shown in FIGS. 7(g) and 9(g). When moved in the horizontal direction, the position where the contact 130 engages with the cam groove 131 moves from the top horizontal portion to the first horizontal portion via the first inclined portion. As a result, as shown in FIGS. 7H and 9H, the support member 112 ascends together with the restriction member 115 in the direction away from the lower folding guide 111, and the plurality of support members 112 are supported by the support member 112. The additional folding roller 114 moves toward the second retracted position located close to the position where the pressing is finished, and the second additional folding process is completed. In the present embodiment, the second retracted position is set to the same position as the receiving position which is the home position. However, it is also possible to set the second retracted position to a position different from the receiving position. When the second additional folding process is completed and the state shown in FIG. 7(h) and FIG. 9(h) is reached, the sheet S can be conveyed from the additional folding portion, and the sheet S is positioned on the upstream side in the carry-in direction. The sheet S is conveyed downstream by the conveying roller pair 102 and the folding roller pair 105 (step S6).

When there are two or more folds such as a Z fold and a tri-fold, the operations from step S3 to step S9 are repeated until the additional fold processing for the last fold is completed, and the fold of the sheet S increases. The conveyance of the sheet is stopped every time it is arranged in the folding portion, and the additional folding rollers 114 are moved along the fold line of the sheet S to perform the additional folding processing (step S10). When the additional folding processing is completed for all the folds, the sheet S subjected to the additional folding processing is conveyed to the post-processing apparatus C. The lower end portions of the additional folding rollers 114 that have been moved to the retracted position and the bottom surface of the regulating member 115 also function as guides for discharging the sheet S that has undergone the additional folding.

In the additional folding unit 104, when the first folding mechanism 114 moves the additional folding roller 114 with respect to the lower folding guide 111 from the retracted position or the receiving position to the pressing position, one end of the fold of the sheet S ( The upstream end in the direction of movement along the fold is arranged between the two additional folding rollers 114 at one extreme position in the pressing member arrangement area, and the other end of the fold (along the fold) The downstream end portion in the moving direction) is arranged outside the pressing member arrangement area (that is, outside the additional folding roller 114 at the other extreme position in the pressing member arrangement area). On the other hand, when the plurality of additional folding rollers 114 are arranged at regular intervals in the direction in which they are moved along the folds, all of the folds located between the adjacent additional folding rollers 114 are added. In order to press between the lower folding guide 111 and the lower folding guide 111, it is necessary to move the plurality of additional folding rollers 114 along the fold line by the distance between adjacent additional folding rollers 114 (that is, the distance of one pitch). is there. Therefore, if the plurality of additional folding rollers 114, that is, the support members 112, are moved along the folds by a distance equal to or more than one pitch of the plurality of additional folding rollers 114, which is the minimum required for performing the additional folding, the folds follow the folds. The additional folding roller 114 at the extreme position on the upstream side in the moving direction crosses over the end of the sheet S on the upstream side in the moving direction and is adjacent to the additional folding roller 114 at the extreme position on the upstream side in the moving direction at the beginning of the movement. The additional folding roller 114 is reliably moved to the position of the additional folding roller 114, and at the beginning of the movement, the end portion of the sheet S located between the two additional folding rollers 114 at the extreme position on the upstream side in the moving direction is pressed to be additionally folded. ..

In addition, in the additional folding unit 104, the movement of the plurality of additional folding rollers 114 along the fold performs the additional folding of the first fold on the outward path, and one sheet S such as Z-folding or inner tri-folding is performed. When a plurality of folds are formed in the back path, the second fold is additionally folded in the return path. Therefore, it is possible to press different folds on the outward path and the return path to perform additional folding processing on a plurality of folds, and suppress an increase in the time required for the additional folding processing, and efficiently and for a plurality of folds in a short time. Additional folding processing can be performed.

In the above description, the additional fold processing by the additional fold unit 104 in the case where the sheet S is Z-folded has been described. However, the additional fold unit 104 may be a double-folded sheet, a quarter-fold, or the like. Seats can also be accommodated. If only one fold is formed on a sheet, such as a double fold, the preceding sheet is ejected after performing additional folding on the fold of the preceding sheet on the outward path, and then on the fold of the following sheet on the return path. By performing the additional fold, the additional fold processing can be efficiently performed on a continuous sheet in a short time. Further, when the sheet has three or more folds, such as a four-fold fold, the conveyance of the sheet is stopped every time the fold reaches below the additional folding roller 114, and the sheet is fed along the fold line in the forward or return path. The additional folding rollers 114 may be moved to perform additional folding. In addition, the folding processing target may be a sheet bundle, a single sheet, a bound sheet bundle, or a unbound sheet bundle.

Although the sheet pressing device of the present invention and the image forming system including the same have been described above with reference to the illustrated embodiments, the present invention is not limited to the illustrated embodiments. In the illustrated embodiment, the guide rail 123, the slider 124, the bracket 125, the pulley 126, the rack 127, the additional folding drive motor 128, the belt 129, the contact 130, the first inclined portion of the cam groove 131, and the second inclined portion. The second moving mechanism 117 is configured by an inclined portion and the guide rail 123, the slider 124, the bracket 125, the pulley 126, the rack 127, the additional folding drive motor 128, the belt 129, the contact 130, and the top of the cam groove 131 are horizontal. However, if the support member 112 can be moved toward and away from the lower folding guide 111 and the support member 112 can be moved along the fold line of the sheet S, the first moving mechanism 116 and the second moving mechanism 116 can be formed. The structure of the moving mechanism 117 is not limited. For example, as shown in FIG. 10, a guide rail 123 and a slider 124 are provided on a base member 142, the slider 124 and the support member 112 are connected by a bracket 125, and the slider 124 is driven by a linear motion mechanism (not shown). By doing so, the support member 112 may be moved horizontally with respect to the base member 142, and the support member 112 may be moved up and down by moving the base member 142 up and down by the elevating mechanism 143. In this case, the guide rail 123, the slider 124, the bracket 125, and the linear movement mechanism function as a second moving mechanism, and the elevating mechanism 146 functions as a first moving mechanism. Further, in this case, the distance between the support member 112 and the lower folding guide 111 at the pressing position can be changed, and the compression amount of the spring 121 at the pressing position can be changed to cause the additional folding roller 114 and the lower folding guide 111 to change. It becomes possible to adjust the pressing force applied to the sheet S in the interval. Therefore, as described above, when the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is smaller than the predetermined threshold value α, the control unit 140, like the second fold 133, performs the additional folding roller 114. When the sheet portion is interposed between the fold and the fold, the sheet fold and the fold between the additional fold roller 114 and the lower folding guide 111 are larger than when the additional fold roller 114 faces and directly contacts the fold. It is possible to control the first moving mechanism 116 so as to weaken the pressing force applied.

Further, in the illustrated embodiment, the additional folding roller 114 is moved to move the additional folding roller 114 with respect to the lower folding guide 111. However, by moving the lower folding guide 111, The additional folding roller 114 may be moved with respect to the lower folding guide 111. Of course, both the additional folding roller 114 and the lower folding guide 111 may be moved. Further, instead of the additional folding roller 114, the lower folding guide 111 may be biased toward the additional folding roller 114 by a spring as an elastic member.

A image forming apparatus B folding processing apparatus C post-processing apparatus 104 additional folding unit 110 upper folding guide 111 lower folding guide 112 support member 113 auxiliary member 114 additional folding roller 115 regulating member 116 first moving mechanism 117 second moving mechanism 118 carry-in guide 118a upper carry-in guide 118b lower carry-in guide 119 carry-in entrance 121 spring 140 control unit 141 sheet basis weight detection sensor

Claims (9)

A sheet pressing device for performing an additional fold on a sheet in which three sheet portions partitioned by two folds formed by a folding process are folded in a Z shape.
A carry-in port for receiving a sheet carried in from a predetermined carrying-in direction after the two folds are formed in advance by the folding process;
A first pressing member arranged downstream of the carry-in direction in the carrying-in direction and pressing the fold line;
A second pressing member that is arranged so as to face the first pressing member and that presses the fold in cooperation with the first pressing member;
A pressing position at which the first pressing member is brought closer to the second pressing member to press the fold line disposed between the first pressing member and the second pressing member, and the pressing position. A first moving mechanism for moving the first pressing member with respect to the second pressing member in a direction away from the sheet to a retracted position,
A second moving mechanism that moves the first pressing member along the fold line in a state where the first pressing member is moved to the pressing position with respect to the second pressing member by the first moving mechanism. A moving mechanism,
A sheet basis weight recognizing means for acquiring basis weight information of the sheet;
A control unit that controls operations of the first moving mechanism and the second moving mechanism;
And the control unit is configured such that the sheet portion is located between the first pressing member and the fold, and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is greater than a predetermined value. When the weight is small, the second moving mechanism is controlled so that the speed of the first pressing member moving along the fold is faster than when the basis weight of the sheet is a predetermined value or more. A sheet pressing device characterized by: When the sheet portion is located between the first pressing member and the fold and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is equal to or more than a predetermined value, the control unit is The second moving mechanism is controlled so that the speed of movement of the first pressing member along the fold is slower than when the first pressing member directly faces the fold. The sheet pressing device described. When the first pressing member directly faces the fold, the control unit makes the speed of movement along the fold of the first pressing member the same regardless of the basis weight of the sheet. The sheet pressing device according to claim 2, wherein the second moving mechanism is controlled. The control unit, when the sheet portion is located between the first pressing member and the fold, and the basis weight of the sheet acquired by the sheet basis weight recognition means is smaller than a predetermined value, 4. The second moving mechanism is controlled so that the speed of movement of the first pressing member along the fold is faster than when the first pressing member directly faces the fold. The sheet pressing device described in. When the sheet portion is located between the first pressing member and the fold and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is equal to or more than a predetermined value, the control unit is The second moving mechanism is arranged so as to increase the number of times of movement of the first pressing member along the fold with respect to one fold, as compared with the case where the first pressing member directly faces the fold. The sheet pressing device according to any one of claims 1 to 4, which is controlled. The sheet pressing device according to claim 1, wherein the first pressing member is an additional folding roller that rotates around a rotation axis extending in the sheet carrying-in direction. The sheet pressing device further includes a support portion and an elastic member, the first pressing member is supported by the supporting member via the elastic member, and is attached by the elastic member toward the second pressing member. The sheet pressing device according to any one of claims 1 to 6, which is biased. When the sheet portion is located between the first pressing member and the fold and the basis weight of the sheet acquired by the sheet basis weight recognizing unit is smaller than a predetermined value, the controller controls the The first pressing member is configured to weaken the pressing force applied to the fold between the first pressing member and the second pressing member, as compared with the case where the first pressing member directly faces the fold. The sheet pressing device according to any one of claims 1 to 7, which controls a moving mechanism. An image forming apparatus which forms an image on a sheet and carries out the image-formed sheet,
A sheet processing apparatus for folding the sheet carried out from the image forming apparatus;
A sheet pressing device according to any one of claims 1 to 8,
An image forming system comprising:

Images