JP7271172B2 - SHEET PRESSING DEVICE AND IMAGE FORMING SYSTEM INCLUDING THE SAME - Google Patents

Description

The present invention relates to a sheet pressing device for folding a sheet and an image forming system such as a copying machine, a printer, a facsimile machine, or a multi-functional machine equipped with the same.

Conventionally, in a sheet folding processing device (post-processing device) installed in an image forming system such as a copier or a printer, the increase in the thickness (folding height) of the crease formed on the sheet due to the folding process has been prevented. For the purpose of preventing this, there is known a method in which a sheet is once folded by a folding unit to form a fold line, and then the fold line is further pressed by another pressing member (additional folding process).

For example, Japanese Patent Application Laid-Open No. 2002-100001 discloses that an additional folding mechanism configured by a plurality of pairs of rollers is arranged in parallel with the pair of folding rollers downstream of a pair of folding rollers that fold the sheet. A sheet processing apparatus is disclosed that performs additional folding without increasing the processing time by continuously applying a load to a folding portion (folding line) with a plurality of pairs of rollers.

Further, Japanese Patent Application Laid-Open No. 2002-200002 discloses a folding roller that folds a 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. A sheet processing apparatus is disclosed which is provided with a fold-enhancing roller for further folding the paper, and which is moved in a direction orthogonal to the paper-conveying direction.

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

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 additional folding are determined. The direction in which the axis extends is the same, and from the viewpoint of crushing the fibers in the crease, the effect of additional folding is reduced compared to the method of additionally folding by moving a repressurizing means such as a roller along the crease. There is a problem.

Further, the paper processing apparatus disclosed in Patent Document 2 described above presses the crease while moving the fold-enhancing roller in the direction orthogonal to the paper conveying direction, so the additional folding method disclosed in Patent Document 1 Compared to , additional folding can be performed efficiently. However, since the effect of additional folding, that is, reinforcement of the crease is obtained by crushing the fibers of the crease, the pressing force exerted by the rotating roller has a large effect. In the case of a sheet in which a plurality of sheet portions partitioned by a plurality of folds are folded through the folds, such as Z-folding, there are cases where the fold-enhancing roller directly contacts the folds and between the fold-enhancing rollers and the folds. There may be cases where the sheet portion is interposed in the In the sheet folding apparatus disclosed in Patent Document 2, pressure is applied under the same conditions regardless of whether or not the sheet portion is interposed between the fold-enhancing roller and the fold-enhancing roller. If the sheet portion is interposed between the fold-enhancing rollers, the pressing force of the fold-enhancing roller is dispersed among the sheet portions, and the pressing force acting on the fold is weakened. Therefore, there is a problem that the effect of the additional folding varies depending on the positional relationship between the additional folding roller, the fold line, and the sheet portion, resulting in a change in the folding height.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the problems existing in the prior art, in order to change the folding height depending on whether or not the roller for additional folding directly contacts the fold of the sheet during additional folding. It is to suppress things.

In view of the above object, the present invention provides, as a first aspect, a first crease and a second crease formed between a first edge and a second edge opposite to the first edge. A sheet pressing device for performing additional folding on a sheet folded in a Z-shape by a fold line, comprising: a first portion between the first fold line and the second fold line; the folded sheet divided into a second portion between the fold and the first edge, and a third portion between the second edge and the second fold, the first portion The second part faces the first surface of the first part, and the third part faces the second surface opposite to the first surface of the first part. a conveying means for conveying so as to overlap ; a pressing roller for pressing the folded sheet by rotating around a rotation axis extending in a conveying direction of the conveying means ; and a facing member arranged to face the pressing roller. and a first position that presses the folded sheet positioned between the pressing roller and the opposing member , and a first position that moves away from the opposing member in the thickness direction of the sheet pressed at the first position . a first moving mechanism for moving the pressing roller between two positions ; and in a state in which the pressing roller is moved to the first position with respect to the opposing member by the first moving mechanism, the first moving mechanism. a second moving mechanism for moving the pressing roller along a direction intersecting the conveying direction so as to press the fold line or the second fold line; The folded sheet is conveyed so that the second portion faces the pressing roller and the third portion faces the opposing member, and the second moving mechanism moves the first fold between the pressing roller and the pressing roller. When the second fold is positioned between the pressing roller and the opposing member , the number of times the pressing roller moves along the intersecting direction is greater than when the second fold is positioned between the pressing roller and the opposing member. To provide a sheet pressing device characterized by increasing the number of times a pressing roller moves along the intersecting direction .

In the above-described sheet pressing device, a crease formed in advance in the carried-in sheet is arranged between the additional folding roller and the pedestal, and the additional folding roller is moved to the pedestal along the crease while being moved to the pressing position. Additional folding of the fold line of the sheet can be performed by moving the folding member. In addition, direct contact with the rotating additional folding roller crushes the fibers in the crease, so the additional folding effect is high. The pressure is distributed among the sheet portions and the pressing force acting on the crease is weakened. However, in the sheet pressing device, when the sheet portion is positioned between the additional folding roller and the fold line, the additional folding roller moves along the fold line at the pressing position more than when the additional folding roller and the fold line face each other directly. Since the number of times of folding is increased, the time for pressing the sheet between the additional folding roller and the pedestal becomes longer, and the total amount of pressing force (work) applied to the sheet portion and the fold between the additional folding roller and the pedestal. increases. Therefore, the total amount of pressing force applied to the fold when the sheet portion is interposed between the additional folding roller and the fold is applied to the fold when the sheet portion is not interposed between the additional folding roller and the fold. Reduction compared to the total amount of pressing force can be suppressed. As a result, fluctuations in the additional folding effect due to the positional relationship between the additional folding rollers, the folds and the sheet portion are suppressed, and the folds with a more uniform folding height regardless of the positional relationship between the additional folding rollers, the folds and the sheet portion. can be realized.

The sheet pressing device further includes sheet basis weight recognition means for acquiring basis weight information of the sheet. When the grammage of the sheet acquired by the recognition means is equal to or greater than a predetermined value, the additional folding roller is positioned at the pressing position at the fold line more than when the grammage of the sheet is smaller than the predetermined value. The second movement mechanism may be controlled so as to increase the number of times it moves along. In the case of a sheet having a basis weight of a predetermined value or more and being difficult to fold, the number of times the additional folding roller is moved along the crease at the pressing position is reduced more than in the case of a sheet having a basis weight smaller than a predetermined value and being easy to fold. Since the number is increased, the time for pressing the sheet between the additional folding roller and the pedestal becomes longer, and the total amount of pressing force (workload) applied to the sheet and the fold between the additional folding roller and the pedestal increases. Therefore, in the case of a sheet having a large grammage and being difficult to fold, the effect of strengthening the crease is enhanced, and it is possible to realize a crease with a more uniform folding height regardless of the grammage of the sheet.

In one embodiment, the sheet pressing device further includes a support member and an elastic member, and the additional folding roller is supported by the support member via the elastic member and attached toward the base by the elastic member. You can make it look like it's being pushed.

When the sheet portion is positioned between the additional folding roller and the fold line, the control unit is configured such that the additional folding roller is positioned at the pressing position more than when the additional folding roller is directly opposed to the fold line. The second movement mechanism may be controlled so as to slow down the speed of movement along the fold. By slowing down the speed at which the additional folding roller moves along the fold at the pressing position, the time for pressing the sheet between the additional folding roller and the pedestal becomes longer, and the sheet portion and the sheet portion are pushed between the additional folding roller and the pedestal. The total amount of pressing force (work) applied to the crease can be increased. Therefore, the total amount of pressing force applied to the fold when the sheet portion is interposed between the additional folding roller and the fold is applied to the fold when the sheet portion is not interposed between the additional folding roller and the fold. Reduction compared to the total amount of pressing force can be further suppressed. As a result, variations in the additional folding effect due to the positional relationship between the additional folding rollers, the folds, and the sheet portion are further suppressed, and the folding height is more uniform regardless of the positional relationship between the additional folding rollers, the folds, and the sheet portion. The effect of providing creases is enhanced.

When the sheet portion is positioned between the additional folding roller and the fold line, the control unit adjusts the distance between the additional folding roller and the base more than when the additional folding roller is directly opposed to the fold line. The first moving mechanism may be controlled so as to increase the pressing force applied to the fold in . By increasing the pressing force applied to the sheet between the additional folding roller and the pedestal, the total amount of pressing force (workload) applied to the sheet portion and folds can be increased. Therefore, the total amount of pressing force applied to the fold when the sheet portion is interposed between the additional folding roller and the fold is Reduction compared to the total amount of pressure can be further suppressed. As a result, variations in the additional folding effect due to the positional relationship between the additional folding rollers, the folds, and the sheet portion are further suppressed, and the folding height is more uniform regardless of the positional relationship between the additional folding rollers, the folds, and the sheet portion. The effect of providing creases is enhanced.

Further, according to a second aspect of the present invention, there is provided an image forming apparatus that forms an image on a sheet and carries out the sheet on which the image is formed, and a sheet processing apparatus that folds the sheet carried out from the image forming apparatus. and the sheet pressing device described above.

According to the present invention, when the sheet portion is positioned between the additional folding roller and the fold, the additional folding roller moves along the fold at the pressing position more times than when the additional folding roller and the fold directly face each other. is increased, the time for pressing the sheet between the additional folding roller and the pedestal becomes longer, and the total amount of pressing force (work) applied to the sheet and the fold between the additional folding roller and the pedestal increases. . Therefore, the total amount of pressing force applied to the fold when the sheet portion is interposed between the additional folding roller and the fold is A decrease compared to the total amount of pressure can be suppressed. Therefore, fluctuations in the additional folding effect due to the positional relationship between the additional folding rollers, the folds, and the sheet portion are suppressed, and the folds with a more uniform folding height are produced regardless of the positional relationship between the additional folding rollers, the folds, and the sheet portion. Realization is possible.

1 is an overall configuration diagram of an image forming system provided with a sheet pressing device of the present invention; FIG. 2 is an explanatory view showing main parts of a folding mechanism and an additional folding unit (corresponding to a sheet pressing device) of the folding device shown in FIG. 1; FIG. FIG. 2 is a view of the additional folding unit of the folding processing apparatus shown in FIG. 1 as seen from the discharge port side; FIG. 4 is an explanatory view showing a mechanism provided inside the additional folding unit shown in FIG. 3 and urging the additional folding roller toward the sheet; FIG. 10A is an explanatory view showing the basic operation of the additional folding section when performing the additional folding process on the sheet in the additional folding unit; (b) is a state in which the additional folding roller is moved to the pressing position and the additional folding roller presses the first fold of the sheet, and (c) is the state in which the sheet is pressed at the pressing position shown in (b). (d) shows a state where the additional folding roller is moved along one fold line, and (d) shows a state where the additional folding roller is moved to the first retracted position from the state shown in (c). FIG. 12E is an explanatory diagram showing the basic operation of the additional folding section when additionally folding the sheet in the additional folding unit; (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; (g) is a state in which the sheet is pressed at the pressing position shown in (f). (h) shows a state in which the additional folding roller is moved along the second fold, and (h) shows a state in which the additional folding roller is moved to the second retracted position from the state shown in (g). 2 is a flow chart showing the operation of the folding device shown in FIG. 1; FIG. 10A is an explanatory view showing the operation of the additional folding unit when performing the additional folding process on the first fold of the sheet in the additional folding unit; (b) is a state in which the first fold on the leading edge side of the sheet in the conveying direction is pressed between the additional folding roller and the pedestal; (c) is the additional folding roller from the state shown in (b); is moved to the first retracted position. FIG. 10D is an explanatory view showing the operation of the additional folding unit when performing the additional folding process on the second fold when the sheet is thick paper in the additional folding unit; (e) is a state in which the second fold on the rear end side of the sheet in the conveying direction is pressed between the additional folding roller and the pedestal, (f) is shown in (e) It shows a state in which the additional folding rollers are moved to the second retracted position from the state in which the folding rollers are in the state. FIG. 3 is a schematic diagram showing a modification of the additional folding unit shown in FIG. 2;

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. In the accompanying drawings, similar components are represented by similar reference numerals.

First, referring to FIG. 1, the overall configuration of an image forming system including a folding device having an additional folding unit, which is a sheet pressing device according to the present invention, will be described. The image forming system includes an image forming apparatus A, a folding apparatus B, and a post-processing apparatus C. A sheet S on which an image is formed by the image forming apparatus A is folded by the folding apparatus B. After that, in the post-processing device C on the further downstream side, stapling processing, alignment processing, etc. are performed as necessary, and the sheet is discharged to the storage tray 27 on the downstream side. Image forming systems include, for example, copiers, printers, and printing machines of various configurations. The image forming apparatus A, the folding device B, and the post-processing device C will be described in detail below.

[Image forming device]
The image forming apparatus A, as shown in FIG. 1, includes an image forming unit A1, an image reading unit A2, and a document feeding unit A3. The image forming unit A1 includes a paper feeding section 2, an image forming section 3, a paper discharging section 4, and a data processing section 5 in the housing 1 of the apparatus.

The paper feeding unit 2 includes a plurality of cassettes 2a, 2b, 2c, and 2d, and each cassette 2a, 2b, 2c, and 2d can store sheets S of different standard sizes that have been selected in advance. . Each of the cassettes 2a, 2b, 2c, and 2d incorporates a separation mechanism for separating the sheets S inside one by one and a sheet feeding mechanism for feeding the sheets S therein. Sheets S stored in the sheet feeding unit 2 having such a configuration are fed to the sheet feeding path 6 in a size specified by a main body control unit (not shown). In the paper feeding path 6, there are conveying rollers 7 arranged in the middle and conveying the sheets S supplied from the plurality of cassettes 2a, 2b, 2c and 2d to the downstream side, and conveying rollers 7 arranged at the end of the path for conveying the respective sheets S to the leading edge. 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 section 3 on the downstream side at a predetermined timing.

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

The image forming unit 3 shown in FIG. 1 includes a photoreceptor 9 (drum, belt) and a light emitter 10 for emitting an optical beam to the photoreceptor 9. A developing device 11 (developer) and a cleaner are provided. (not shown) are arranged around the rotating photoreceptor 9 . The illustrated one is a monochrome printing mechanism, in which a light emitting device 10 optically forms a latent image on a photosensitive member 9, and a developing device 11 adheres toner ink to the latent image. The ink image (ink toner) adhered to the photosensitive member 9 is image-transferred by the transfer charger 12 onto the sheet S sent from the paper supply unit 2. After the image-transferred sheet S is fixed by the fixing roller 13, It is sent to the discharge path 14 . Further, the image forming section 3 is provided with a circulation path 17, and after the sheet S from the discharge path 14 is turned upside down in a switchback path, it is sent again to the registration rollers 8, and an image is formed on the back side of the sheet S. is removed and sent to the discharge path 14 . A paper discharge roller 15 is arranged in the paper discharge path 14, and a paper discharge port 16 is formed at the end thereof. do.

Above the image forming unit A1 configured as described above, a document reading unit A2 for optically reading a document image formed by the image forming section 3 is provided. A feeding unit A3 is mounted.

The image reading unit A2 includes a first platen 18 and a second platen 19 made of transparent glass, a reading carriage 20, a light source mounted on the reading carriage 20, a photoelectric conversion element 21, mirrors and lenses. The scanning carriage 20 scans the reading carriage 20 along the first platen 18 to apply light from the light source to the image of the document sheet S placed on the first platen 18 . The light reflected from the image on the document sheet S is guided to the photoelectric conversion element 21 by the reduction optical system 22, and the image is read. The photoelectric conversion element 21 converts the image data into an electric signal and transfers it to the image forming section 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 documents placed on the paper feed tray 23 one by one along the paper feed path 24. Then, it passes over the second platen 19 and is discharged to the discharge tray 25 . When reading a document fed from the document feeding unit A3 and passing over the second platen 19, the reading carriage 20 is previously stopped below the second platen 19, and the reading carriage 20 is stopped above the second platen 19. to generate image data from the image passing through the .

[Post-processing device]
The post-processing device C is connected further downstream of the folding processing device B connected to the image forming device A, and the sheet that has been folded by the folding processing device B or discharged without being subjected to the folding processing. The sheet S is received and subjected to stapling processing, alignment processing, etc. as necessary.

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

[Folding device]
The folding device B connected to the image forming apparatus A is a device that receives the image-formed sheet S ejected from the sheet ejection port 16 of the image forming apparatus A and folds the sheet.

FIG. 2 shows the internal configuration of the folding device B. As shown in FIG. The folding device B includes a control unit 140 that controls the operation of the folding device B. Inside the folding device B, a transport path 101 extending 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 as sheet basis weight recognition means, and a folding mechanism 103 arranged downstream 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 . The folding processing apparatus B folds the sheet S transported along the transport path 101 by the folding processing mechanism 103, and then performs additional folding by the additional folding unit 104, thereby performing the folding processing and the additional folding processing. The sheet S can be handed over to the post-processing device C.

As shown in FIG. 1, the transport path 101 is arranged so as to be continuous with the sheet ejection port 16 of the image forming apparatus A, and the sheet S ejected from the sheet ejection port 16 is conveyed through the transport path 101. It can be carried into the folding processing device B. 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. It can be brought in.

The conveying roller pair 102 is formed of rubber rollers and includes an upper conveying roller 102a arranged on the upper side and a lower conveying roller 102b arranged on the lower side facing the upper conveying roller 102a. In this embodiment, the upper conveying roller 102a is connected to a conveying roller drive motor (not shown) and is rotated as the conveying roller drive motor rotates, while the lower roller 102b is connected to the conveying roller drive motor (not shown). It is pressed against the upper conveying roller 102a by the urging force of the spring that is not engaged, and rotates in a driven manner. However, the transport roller pair 102 is not limited to the configuration described above as long as the sheet S can be transported, and an appropriate configuration can be adopted.

A sheet basis weight detection sensor 141, which is a sheet basis weight recognition unit, obtains information about the basis weight of the sheet S conveyed on the conveying path 101 by, for example, ultrasonic waves, and the obtained information about the basis weight of the sheet S is controlled. 140, and used in additional folding processing in the additional folding unit 104 as described later. Since the sheet grammage detection sensor 141 is a known technique, detailed description of the measurement principle and structure is omitted here. In this embodiment, the sheet basis weight detection sensor 141 is used as the sheet basis weight recognition means, but it is not limited as long as it can acquire information about the basis weight of the sheet S. For example, as the sheet grammage recognition means, a data storage unit storing information on grammage corresponding to various sheet types is used, and information such as the type of sheet S selected by the operator when using the image forming system is used. Information regarding the basis weight of the sheet S may be provided to the control unit 140 .

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

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 conveying guide 108 is formed from immediately behind the conveying roller pair 102 to above the thrust plate 107 so as to guide the leading edge of the sheet S from the conveying roller pair 102 to the thrust plate 107 . The upper conveying guide 108 is for regulating the flow of the sheet S conveyed along the conveying path 101, is arranged above the conveying path 101, and has a shape bent downward toward the downstream side. . The upper folding guide 110 is arranged between the upper conveying guide 108 and the folding roller pair 105 , and guides the leading edge of the sheet S and a folded portion of the sheet S to be described later to the folding roller pair 105 . It extends to the front. The upper folding guide 110 is for regulating the flow of the sheet S in the folding mechanism 103 , and is provided downstream of the upper transport guide 108 and above the transport path 101 .

The lower conveying guide 109 is for regulating the flow of the sheet S conveyed along the conveying path 101, and is arranged below the conveying path 101. Similar to the upper conveying guide 108, the lower conveying guide 109 is arranged downstream. It has a downward curved shape. The lower conveying guide 109 is cut off before the sliced plate 107, and an open space is formed downstream of the lower conveying guide 109. As shown in FIG. The lower folding guide 111 is disposed on the downstream side of the veneer 107 and extends across the upstream and downstream sides of the folding roller pair 105 . The portion has a horizontal surface for guiding the leading edge of the conveyed sheet S and a folded portion of the sheet S, which will be 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 sliced plate 107 is moved horizontally by a sliced plate driving device (not shown) and a controller 140 . Also, the thrust plate 107 fills the space between the lower conveying guide 109 and the lower folding guide 111 when the conveying roller pair 102 conveys the sheet S to the folding roller pair 105 along the conveying path 101 . It is arranged so as to guide the leading edge of the conveyed sheet S 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 folding roller pair 105 in the sheet S conveying 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 regulating member 115 attached to the support member 112, and a lower folding guide for the support member 112. A first moving mechanism 116 for moving toward and away from 111 and a second moving mechanism 117 for horizontally moving the support member 112 along the fold of the sheet S are provided. Portions of the upper folding guide 110 and the lower folding guide 111 that face each other vertically and 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 . , upstream ends of the pair of carry-in guides 118 form a carry-in opening 119 of the additional folding unit 104 . Further, the additional folding portion is constituted by the plurality of additional folding rollers 114 supported by the support member 112 and the lower folding guide 111 as described above, and the lower folding guide 111 facing the additional folding rollers 114 in the vertical direction. A portion (hereinafter referred to as a pedestal portion) functions as a pedestal.

Each of the plurality of additional folding rollers 114 is rotatable around a rotation axis extending in the conveying direction of the sheet S (the direction parallel to the upper surface of the pedestal portion of the lower folding guide 111 and perpendicular to the fold of the sheet S). In addition, they are arranged in the pressing member arrangement area along the folding line direction of the sheet S at a constant interval from each other and are supported by the supporting member 112 . Also, the first moving mechanism 116 moves the support member 112 supporting the plurality of additional folding rollers 114 in a direction toward and away from the pedestal portion of the lower folding guide 111 . As a result, the plurality of additional folding rollers 114 are caused to approach and separate from the pedestal portion of the lower folding guide 111, and the fold lines of the sheet S disposed between each of the additional folding rollers 114 and the pedestal portion of the lower folding guide 111 are formed. are pressed by the additional folding rollers 114 and the pedestal portion of the lower folding guide 111 and a retracted position where the plurality of additional folding rollers 114 are moved away from the pressing position in the direction away from the sheet S. It has become. Further, the second moving mechanism 117 can move the plurality of additional folding rollers 114 along the folds of the sheet S by moving the support member 112 in the horizontal direction (horizontal direction in FIG. 3) at the pressing position. ing. Note that the plurality of additional folding rollers 114 and the pedestal portion of the lower folding guide 111 are in direct contact with each other unless the sheet S is interposed therebetween at the pressing position. The length of the pressing member arrangement area (i.e., the distance between the additional folding rollers 114 arranged at the extreme positions of the pressing member arrangement area) is set so that it is adjacent to one extreme position when moved from the retracted position to the pressing position. One end of the fold of the sheet S (the end on the upstream side of the moving direction of the additional folding roller 114) is arranged between the two additional folding rollers 114 arranged, and the additional folding roller is arranged at the other extreme position. 114 is determined to be positioned on the fold line. Preferably, as in the illustrated embodiment, the length of the pressing member arrangement area, that is, the length between the additional folding rollers 114 arranged at the extreme positions of the pressing member arrangement area, is carried into the additional folding unit 104. 1 pitch of the array of the additional folding rollers 114 (one interval between two additional folding rollers arranged adjacent to each other) is shorter than the length of the fold of the sheet S on which the sheet S is folded. 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. In addition, since the number of additional folding rollers 114 supported by the support member 112 is reduced, when the same force is applied to the support member 112, the pressing force per additional folding roller 114 against the sheet S is increased. The folding effect is enhanced, and efficient additional folding is possible with a smaller force.

In the additional folding unit 104, the additional folding unit 104 is operated in a state in which the plurality of additional folding rollers 114 are arranged at the receiving position away from the pedestal portion of the lower folding guide 111 toward the retracted position or the pressing position. receives a sheet S inside. Thereafter, the position of the sheet S is detected by sheet position detection means (not shown) provided upstream of the folding roller pair 105, and when the fold of the sheet S reaches below the folding rollers 114, the sheet S is folded. Then, the first moving mechanism 116 moves the plurality of additional folding rollers 114 to the pressing position against the pedestal portion of the lower folding guide 111 . When the plurality of additional folding rollers 114 move to the pressing position, one end of the fold (the upstream end in the direction of movement along the fold) of the sheet S is positioned at one extreme position in the pressing member arrangement area. , while the other end of the fold (end on the downstream side in the direction of movement along the fold) is outside the pressing member arrangement area (i.e., the pressing member arrangement area outside of the additional folding roller 114 at the other extreme position in the direction) is carried into the additional folding unit 104 . Further, the plurality of additional folding rollers 114 are moved along the folds of the sheet S with respect to the pedestal portion of the lower folding guide 111 at the pressing position by the second moving mechanism 117 , thereby folding the sheet with the plurality of additional folding rollers 114 . Further folding is performed by pressing the S fold over the entire fold to strengthen the fold. In this way, each additional folding roller 114 and the lower folding guide 111 (more specifically, its pedestal portion) function as pressing members.

Further, a regulating member 115 having a substantially L-shaped cross section attached to the support member 112 is disposed outside the additional folding rollers 114 at the extreme positions and between the additional folding rollers 114 that are spaced apart from each other. The regulating member 115 moves the additional folding roller 114 along the crease of the sheet S at a position where the additional folding roller 114 is pressed against the pedestal portion of the lower folding guide 111 to perform additional folding. (that is, the surface facing the pedestal portion of the lower folding guide 111) and the upper surface of the pedestal portion of the lower folding guide 111 is the height of the normal conveying path, for example, when the additional folding unit 104 is carried in. It is placed at a regulating position that is shorter than the distance d2 between the pair of carry-in guides 118 (upper carry-in guide 118a and lower carry-in guide 118b) that form the carry-in path leading to the port 119, and is positioned together with the support member 112 while maintaining the distance d1. It moves along the fold of the sheet S. The distance d1 between the bottom surface of the regulating member 115 and the top surface of the pedestal portion of the lower folding guide 111 is determined so that these members do not come into direct contact with each other. As a result, prior to pressing by the additional folding rollers 114, the regulating member 115 pushes down the fold to be lower than the height between the upper carry-in guide 118a and the lower carry-in guide 118b. Additional folding can be performed by pressing the crease.

The gaps between the plurality of additional folding rollers 114 and the pedestal portion of the lower folding guide 111 and the gaps between the regulating member 115 and the pedestal portion of the lower folding guide 111 are in the direction along the fold of the sheet S. is kept constant over the entire range.

As shown in FIG. 4, a plurality of additional folding rollers 114 are rotatably attached to auxiliary members 113 that are movably supported with respect to the support member 112, and formed on the support member 112. A spring 121 is arranged as an elastic member between the spring receiving portion 120 and the upper end portion of each auxiliary member 113 to bias the additional folding roller 114 toward the pedestal portion of the lower folding guide 111 . is preferred. With such a configuration, when the support member 112 of the additional folding unit 104 and the regulating member 115 attached thereto move downward toward the pedestal portion of the lower side folding guide 111, the additional folding roller 114 is The downward movement is stopped when the sheet S contacts the pedestal portion of the lower folding guide 111 . On the other hand, the support member 112 and the regulating member 115 can continue to move downward due to the contraction of the spring 121, and the distance between the bottom surface of the regulating member 115 and the top surface of the pedestal portion of the lower folding guide 111 is a desired value. It becomes possible to stop the regulating member 115 when it reaches the regulating position. Further, if each auxiliary member 113 is biased by an individual spring 121, even if the support member 112 is slightly tilted and moves along the fold of the sheet S, the additional folding rollers 114 do not move toward the fold of the sheet S. Therefore, it is possible to prevent uneven additional folding due to a change in the pressing force depending on the crease portion. 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 reliably 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 housing 122 of the folding processing apparatus B or the like via a bracket 125 so as to be vertically movable. It moves in conjunction with the slider 124 in the horizontal direction. A rack 127 that engages with a pinion (not shown) that rotates integrally with a pulley 126 is provided on the slider 124 . 126 to rotate the pulley 126 , the slider 124 can be moved horizontally along the guide rail 123 .

Further, the support member 112 is formed with a cam groove 131 that engages with a contactor 130 fixed to the housing 122 of the folding device B or the like. As the support member 112 moves horizontally, the cam groove 131 moves while being engaged with the contactor 130 , and the support member 112 moves while being guided according to the shape of the cam groove 131 . The cam groove 131 includes a first bottom horizontal portion extending substantially horizontally, a first inclined portion extending obliquely upward from the end of the first portion, and a substantially horizontal portion extending from the end of the first inclined portion. An extending top horizontal portion, a second sloping portion extending downwardly from an end of the top horizontal portion, and a second bottom horizontal portion extending generally horizontally from the end of the second sloping portion. Support is achieved by moving the support member 112 in the horizontal direction in FIG. The member 112 moves toward and away from the pedestal portion of the lower folding guide 111, that is, moves vertically in FIG. Thus, 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 contactor 130, and the first and second inclined portions of the cam groove 131 are the first and second inclined portions. 1 moving mechanism 116 is configured. Further, by moving the support member 112 in the horizontal direction in the drawing with respect to the housing 122 by the slider 124 while engaging the top horizontal portion of the cam groove 131 with the contactor 130, the support member 112 and the support member 112 supported by this are moved. A plurality of additional folding rollers 114 move along the folds of the sheet S in the horizontal direction in FIG. Thus, the guide rail 123, the slider 124, the bracket 125, the pulley 126, the rack 127, the additional folding driving motor 128, the belt 129, the contactor 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 or the like and the cam groove 131 is formed in the support member 112. However, the contact 130 is fixed to the support member 112 and the cam groove 131 is formed in It goes without saying that it may be formed on the body 122 as well.

Note that when a plurality of additional folding rollers 114 are arranged at regular intervals as in the illustrated embodiment, all folds positioned between adjacent additional folding rollers 114 are folded by the additional folding rollers. In order to press between 114 and the pedestal portion of the lower folding guide 111, the pedestal portion of the lower folding guide 111 must be pushed at the pressing position by at least the interval between the adjacent additional folding rollers 114 (that is, the distance of one pitch). It is necessary to move a plurality of additional folding rollers 114 along the folds. In the configuration of the first moving mechanism 116 described above, the slider 124 is horizontally moved while the contactor 130 and the first inclined portion of the cam groove 131 are engaged with each other to move the plurality of sliders supported by the support member 112 . The additional folding roller 114 approaches the pedestal portion of the lower folding guide 111 and is moved to the pressing position. In addition, in the configuration of the second moving mechanism 117 described above, by moving the slider 124 in the horizontal direction while engaging the contactor 130 with the top horizontal portion of the cam groove 131, the plurality of moving mechanisms supported by the support member 112 are moved. The additional folding roller 114 moves along the fold at the pressing position. Therefore, the length of the top horizontal portion of the cam groove 131 in the horizontal direction (direction along the crease) is equal to or longer than one pitch of the adjacent additional folding rollers 114 .

During the additional folding process, the control unit 140 controls the additional folding roller 114 so that the additional folding roller 114 directly faces the fold without interposing a sheet portion (the portion where the sheet S is divided by the fold) between the additional folding roller 114 and the fold. When contacting, the second moving mechanism moves the plurality of additional folding rollers 114 arranged at the pressing position by the first moving mechanism 116 along the fold a predetermined number of times N1 with respect to one fold. 117. On the other hand, when the sheet portion is interposed between the additional folding rollers 114 and the fold line during the additional folding process, the control unit 140 moves the additional folding rollers 114 arranged at the pressing position by the first moving mechanism 116 . The second moving mechanism 117 is controlled so as to move along one fold N2, which is greater than N1, along the fold. Here, the unit number of times of movement along the crease means that the support member 112 moves along the crease of the sheet S, so that the entire crease is additionally folded. Specifically, the unit is a one-way stroke in which the contactor 130 and the cam groove 131 are engaged with each other from one end to the other end of the top horizontal portion of the cam groove 131, or from the other end to the one end. number of times.

When the additional folding rollers 114 arranged at the pressing position are repeatedly moved along the folding line for a number of times N2 which is larger than the number of times N1, the plurality of additional folding rollers 114 and the pedestal portion of the lower folding guide 111 are moved. Since the time to apply the pressing force to the fold is longer, the additional folding roller 114 and the pedestal portion of the lower folding guide 111 are moved more than when the plurality of additional folding rollers 114 are moved along the fold N1 times. The total amount of pressing force (workload) applied to the sheet portions and folds between . When the sheet portion is interposed between the additional folding roller 114 and the fold, the pressing force is dispersed by the sheet portion and the pressing force applied to the fold decreases. If the folding roller 114 is moved along the fold N2 times, which is greater than the number N1, the pressing force applied to the fold is offset by the sheet portion interposed between the additional folding roller 114 and the fold. Between the additional folding roller 114 and the pedestal portion of the lower folding guide 111, the total amount of pressing force (work) applied to the sheet portion and the fold increases. Therefore, the total amount of pressing force applied to the fold when the sheet portion is interposed between the additional folding roller 114 and the fold is equal to the total amount of pressing force applied when the additional folding roller 114 and the fold are in direct contact with each other. It is possible to prevent the pressure from becoming smaller than the total amount of pressure. As a result, variation in the effect of additional folding due to the positional relationship between the additional folding roller 114, the fold, and the sheet portion is suppressed, and the fold with a more uniform folding height can be realized.

Next, with reference to FIGS. 5 to 9, the operations of the folding apparatus B and the additional folding unit 104 of the illustrated embodiment will be described in detail. Here, folding processing is performed by the folding processing mechanism 103 as described above, and the sheet is divided into three sheet portions by the first folding line 132 and the second folding line 133, and the first folding line 132 is the upper side of the sheet portion. and the second fold line 133 is positioned on the lower side of the sheet portion is carried into the additional folding unit 104, and a thin sheet as the sheet S with a small basis weight, It is assumed that a sheet of thick paper or plain paper is carried into the additional folding unit 104 as the sheet S having a large basis weight.

First, with reference to FIGS. 5 and 6, the basic operation of the additional folding process for the sheet S having a plurality of folds will be described. When the sheet S from the folding mechanism 103 is received into the additionally 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, FIG. Thus, the plurality of additional folding rollers 114 supported by the supporting member 112 are arranged at the receiving position, which is the home position. At this time, the lower end portions 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. It functions as a guide that guides the first fold line 132 to between the additional folding roller 114 and the lower folding guide 111 . Also, at this time, the contactor 130 is positioned at the end of the first bottom horizontal portion of the cam groove 131 . In the illustrated embodiment, a second retracted position, which will be described later, is the receiving position. However, if the additional folding roller 114 and the pedestal portion of the lower folding guide 111 are separated from each other by being located on the retracted position (first retracted position or second retracted position) side of the pressing position, The receiving position may be set at a position different from the second retracted position.

The position of the sheet S is detected by a sheet position detection means (not shown) provided upstream of the folding roller pair 105, and the front end side of the sheet S carried into the carry-in port 119 from the folding roller pair 105 is detected. When it is recognized that the first fold line 132 has reached below the additional folding roller 114 , the conveying of the sheet S is stopped, and the additional folding drive motor 128 is driven to rotate the pinion and rack integrally with the pulley 126 . 127 to move the support member 112 together with the slider 124 in the horizontal direction. As a result, the portion where the contactor 130 engages with the cam groove 131 moves from the first bottom horizontal portion to the first inclined portion, and accordingly the support member 112 is directed toward the pedestal portion of the lower folding guide 111. 5(b), a plurality of additional folding rollers 114 supported by the support member 112 are placed between the base portion of the lower folding guide 111 and the first sheet S. It moves to a pressing position where it pinches and presses the crease 132 . At this time, one end of the first fold line 132 of the sheet S (the upstream end in the direction of movement of the additional folding rollers 114 in the forward pass) is positioned at one extreme position of the adjacent two additional folding rollers 114 . The additional pushing roller 114 disposed between and at the other extreme position is placed on the first fold 132 of the sheet S, and the other end of the first fold 132 of the sheet S (outward travel) is placed on the first fold 132 of the sheet S. downstream end in the moving direction of the additional folding roller 114 at ( ) is arranged outside the pressing member arrangement area (see FIG. 5B). In FIG. 5B, one end of the first fold line 132 of the sheet S is shown to be located at the middle position between the two adjacent additional folding rollers 114 located at the extreme positions. , "between the 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 one end of the first fold line 132 of the sheet S. Positions matching 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 is lowered, and the additional folding roller 114 is pushed through the sheet S. Even after coming into contact with the pedestal portion of the lower folding guide 111, the support member 112 can be further lowered. Along with this, the regulating member 115 also descends further to press the first crease 132 of the sheet S positioned below the additional folding roller 114, thereby reducing the thickness of the crease of the sheet S to a predetermined thickness or less. to regulate. Further, each additional folding roller 114 presses the first fold line 132 of the sheet S toward the pedestal portion of the lower folding guide 111 by being biased by the spring 121 . Note that the carry-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 opening 119 .

When the support member 112 is further horizontally moved together with the slider 124 by driving the additional folding drive motor 128 from the state shown in FIG. The point where 130 engages cam groove 131 moves from the first sloping portion to the top horizontal portion. Then, the regulating member 115 attached to the supporting member 112 regulates the thickness of the first fold line 132 of the sheet S to a predetermined thickness (corresponding to the distance d1) or less, and the plurality of folding lines 132 supported by the supporting member 112 are regulated. The additional folding rollers 114 are moved at the pressing position relative to the pedestal portion of the lower folding guide 111 along the first fold line 132 of the sheet S by a distance equal to or greater than one pitch of the plurality of additional folding rollers 114. The leading additional folding roller 114 in the direction moves over the other end of the first fold line 132 of the sheet S (the downstream end in the moving direction of the additional folding roller 114 in the forward pass). Specifically, the other end of the first fold line 132 of the sheet S is arranged between two adjacent additional folding rollers 114 arranged at the other extreme position and additionally folded at one extreme position. When the roller 114 is placed on the first fold of the sheet S, one end of the first fold 132 of the sheet S (upstream end in the direction of movement of the additional folding roller 114 in the forward pass) is pressed. It is arranged outside the member placement area (see FIG. 5(c)). In FIG. 5C, the other end of the first fold line 132 of the sheet S is shown to be arranged at the intermediate position between the two adjacent additional folding rollers 114 arranged at the extreme positions. , "between the 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 the other end of the first fold line 132 of the sheet S. Positions matching part are also included. In this way, the additional folding roller 114 and the pedestal portion of the lower folding guide 111 press the first fold line 132 over the entire area to strengthen the first fold line 132, that is, perform additional folding.

When the support member 112 is further horizontally moved together with the slider 124 by driving the additional folding drive motor 128 from the state shown in FIG. portion through a second slanted portion to a second bottom horizontal portion. As a result, as shown in FIG. 5(d), the support member 112 is lifted together with the regulating member 115 in the direction away from the base portion of the lower folding guide 111, and a plurality of additional foldings supported by the support member 112 are performed. The roller 114 moves to the first retracted position located above and close to the position where the pressing is finished, 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 FIG. 5D is reached, the sheet S can be conveyed by the conveying roller pair 102 and the folding roller pair 105 located on the upstream side in the carry-in direction. Become. The sheet S is conveyed by the conveying roller pair 102 and the folding roller pair 105 from the state shown in FIG. Then, when it is recognized that the second fold line 133 located on the rear end side in the carry-in direction of the first fold line 132 has reached below the additional folding roller 114, the sheet S is stopped to be conveyed.

When the second fold line 133 of the sheet S is stopped below the additional folding roller 114 (see FIG. 6(e)), the additional folding drive motor 128 is driven to rotate in the direction opposite to that of the outward path. The support member 112 is horizontally moved together with the slider 124 via the pinion and the rack 127 that rotate integrally with the pulley 126 in a direction opposite to that during the outward travel. As a result, the portion where the contactor 130 engages with the cam groove 131 moves from the second bottom horizontal portion to the second inclined portion, and along with this, the support member 112 is directed toward the pedestal portion of the lower folding guide 111. 6(f), a plurality of additional folding rollers 114 supported by the supporting member 112 are placed between the base portion of the lower folding guide 111 and the second sheet S. It moves to a pressing position where it pinches and presses the crease 133 . At this time, the positions of the plurality of additional folding rollers 114, that is, the position of the starting point of the return pass, is the same position as the position of the end point of the forward pass. Further, at this time, one end of the second fold line 133 of the sheet S (upstream end in the movement direction of the additional folding roller 114 in the return path) is positioned at one extreme position of the adjacent two additional folding rollers. The additional folding roller 114 arranged between 114 and arranged at the other extreme position is placed on the second fold line 133 of the sheet so that the other end of the second fold line 133 of the sheet S ( The downstream end in the moving direction of the additional folding roller 114 in the return path) is arranged outside the pressing member arrangement area (see FIG. 6(f)). Further, since the auxiliary member 113 to which the additional folding roller 114 is attached is urged by the spring 121 toward the pedestal portion of the lower side folding guide 111, the support member 112 descends, and the additional folding roller 114 moves the sheet S. The support member 112 can be further lowered even after contacting the pedestal portion of the lower folding guide 111 via the support member 112 . Along with this, the regulating member 115 is also further lowered to press the sheet portion of the sheet S positioned below the additional folding roller 114 and the second fold line 133, thereby reducing the thickness of the sheet S to a predetermined thickness or less. It regulates the thickness of the portion and the second fold 133 . Further, each additional folding roller 114 presses the sheet portion of the sheet S and the second folding line 133 toward the pedestal portion of the lower folding guide 111 by being biased by the spring 121 .

When the support member 112 is further horizontally moved together with the slider 124 from the state shown in FIG. 6(f) by driving the additional folding drive motor 128, the state shown in FIG. 6(g) is obtained. , the point where the contactor 130 engages the cam groove 131 moves from the second inclined portion to the top horizontal portion. Then, the regulating member 115 attached to the support member 112 adjusts the thickness of the sheet portion of the sheet S positioned below the additional folding roller 114 and the thickness of the second fold line 133 to a predetermined thickness (corresponding to the distance d1). The plurality of additional folding rollers 114 supported by the support member 112 are regulated to the following and are directed opposite to the forward path along the second fold line 133 of the sheet S against the pedestal portion of the lower folding guide 111 at the pressing position. Then, the leading additional folding roller 114 in the moving direction moves over the end of the second fold line 133 of the sheet S. As shown in FIG. In this way, the additional folding roller 114 and the pedestal portion of the lower folding guide 111 press the entire area of the second fold line 133 to strengthen the second fold line 133, that is, perform additional folding.

From the state shown in FIG. 6G, when the additional folding drive motor 128 is driven to move the support member 112 together with the slider 124 in the horizontal direction in the opposite direction to the outward movement, the contactor 130 engages with the cam groove 131. The point to be moved moves from the top horizontal portion to the first horizontal portion via the first sloping portion. As a result, as shown in FIG. 6(h), the supporting member 112 is lifted together with the regulating member 115 in a direction away from the pedestal portion of the lower folding guide 111, and a plurality of additional foldings supported by the supporting member 112 are performed. The rollers 114 move to the second retracted position located close to the position where the pressing is finished, and the second additional folding process is completed. In this embodiment, the second retracted position is set at the same position as the receiving position, which is the home position. However, it is also possible to set the second retracted position at a position different from the receiving position.

After completing a series of additional folding operations in this manner, the sheet S is conveyed toward the post-processing apparatus C on the downstream side by the conveying roller pair 102 and the folding roller pair 105 located on the upstream side in the carry-in direction. The lower end portions of the plurality of additional folding rollers 114 and the bottom surface of the regulating member 115 that have been moved to the retracted position also function as guides when the additionally folded sheet S is discharged.

In the additional folding unit 104, when the additional folding roller 114 is moved from the retracted position or the receiving position to the pressing position with respect to the pedestal portion of the lower folding guide 111 by the first moving mechanism 116, one of the folds of the sheet S is folded. The end portion (the upstream end portion 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 portion of the fold (the fold line downstream side in the direction of movement along ) 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 a plurality of additional folding rollers 114 are arranged at regular intervals in the direction in which they are moved along the folds, all the folds located between the adjacent additional folding rollers 114 are and the pedestal portion of the lower folding guide 111, the plurality of additional folding rollers 114 must be moved along the crease by at least the distance between the adjacent additional folding rollers 114 (that is, the distance of one pitch). need to let Therefore, if the plurality of additional folding rollers 114, that is, the support member 112 is moved along the crease by a distance equal to or more than one pitch of the plurality of additional folding rollers 114, which is the minimum required for additional folding, the folds can be folded along the crease. The additional folding roller 114 at the extreme position on the upstream side in the movement direction passes over the edge of the sheet S on the upstream side in the movement direction, and is positioned adjacent to the additional folding roller 114 at the extreme position on the upstream side in the movement direction at the start of movement. The sheet S is reliably moved to the position of the additional folding roller 114, and the end portion of the sheet S positioned between the two additional folding rollers 114 at the extreme position on the upstream side in the moving direction is pressed and additionally folded at the beginning of the movement. .

Further, in the additional folding unit 104, the movement of the plurality of additional folding rollers 114 along the fold line is performed by performing additional folding at the first fold line in the forward pass, and folding one sheet S by Z-folding, inward three-folding, or the like. When a plurality of creases are formed on the sheet, additional folding is performed on the second crease in the return trip. Therefore, the additional folding can be applied to a plurality of folds by pressing different creases in the forward and return passes, so that the increase in the time required for the additional folding can be suppressed, and the plurality of folds can be processed efficiently and in a short time. Additional folding can be performed by pressing the

In the above description, the additional folding processing by the additional folding unit 104 when the sheet S is Z-folded has been described. Sheets can also be accommodated. When only one fold line is formed on the sheet, such as when the sheet is folded in half, the fold line of the preceding sheet is additionally folded in the forward pass, the preceding sheet is discharged, and the fold line of the succeeding sheet is folded in the return pass. By additionally folding, continuous sheets can be efficiently additionally folded in a short time. Furthermore, when three or more creases are formed on the sheet, such as when the sheet is folded in four, the conveyance of the sheet is stopped each time the crease reaches below the additional folding roller 114, and the sheet is fed along the crease on the outward or return path. The additional folding can be performed by moving the plurality of additional folding rollers 114 by pressing. In addition, the object to be folded may be a sheet bundle, a single sheet, a bound sheet bundle, or an unbound sheet bundle.

Next, referring to FIGS. 7 to 9, the control performed by the control unit 140 of the folding processing apparatus B during the additional folding process shown in FIGS. 5 and 6, particularly the second moving mechanism 117 Control will be explained in detail. Here, as shown in FIGS. 8 and 9, in a Z-shape such that the first fold 132 is above the sheet portion and the second fold 133 is below the sheet portion. Description will be made on the assumption that the folded sheet S is carried into the additional folding unit 104 .

In the folding device B, first, the folding mechanism 103 folds the sheet S so that the first folding line 132 is positioned above the sheet portion and the second folding line 133 is positioned below the sheet portion. Next, the sheet S is folded into a Z shape (step S1). Specifically, upon recognizing that the leading edge of the sheet S has been nipped by the pair of folding rollers 105, the control unit 140 controls the folding mechanism 103 to horizontally move the veneer 107 to form a folded portion. A space for forming a loop is formed between the lower transport guide 109 and the lower folding guide 111 by moving it to the retracted position below the lower transport guide 109 . After the space for forming the loop is formed, when the sheet S is conveyed by a predetermined amount while the leading edge of the sheet S is nipped by the pair of folding rollers 105, the intermediate portion of the sheet S is bent downward in the space for forming the loop. to create the loop part. In this state, the thrust plate 107 is horizontally moved from the retracted position toward the folding roller pair 105 to form a folded portion. By driving and conveying the sheet S, the first fold line 132 is formed, and after the thrust plate 107 is moved to the retracted position, the sheet S is conveyed by the folding roller pair 105 to nip the loop portion. , a second fold line 133 is formed, and the Z-folded sheet S is conveyed downstream.

The sheet S folded by the folding mechanism 103 is carried into the additional folding unit 104 through the inlet 119 by the pair of folding rollers 105 (step S2). In the additional folding unit 104, the additional folding unit 104 is operated in a state in which the plurality of additional folding rollers 114 are arranged at the receiving position away from the pedestal portion of the lower folding guide 111 toward the retracted position or the pressing position. receives a sheet S inside. At this time, the control unit 140 controls the position of the sheet S as shown in FIG. , when it is recognized that the first crease 132 on the front end side in the carry-in direction of the sheet S carried into the carry-in port 119 from the folding roller pair 105 has reached the additional folding portion, that is, below the additional folding roller 114 . is stopped (step S3).

When the first fold line 132 stops at the additionally folded portion, the control unit 140 drives the first moving mechanism 116 to cause a plurality of folds supported by the support member 112, as shown in FIG. 8(b). The additional folding roller 114 is moved to the pressing position. After that, the control unit 140 drives the second moving mechanism 117 to move the additional folding rollers 114 along the first folding line 132 to the pedestal portion of the lower folding guide 111 at the pressing position. The first fold line 132 is pressed by the additional folding roller 114 and the pedestal portion of the lower folding guide 111 to strengthen the first fold line 132, that is, perform additional folding.

When the additional folding roller 114 is moved along the fold at the pressing position as described above, the control unit 140 controls the operation of the second moving mechanism 117 to determine whether the additional folding roller 114 can come into direct contact with the fold. Based on whether or not there is a sheet portion interposed between the additional folding roller 114 and the fold line, the number of times the additional folding roller 114 is moved along the fold line is changed (step S4). ).

When the fold is positioned above the sheet portion and the additional folding roller 114 can directly contact the fold, such as the first fold 132 on the leading side of the sheet S in the conveying direction, the control unit 140 operates the second moving mechanism. By controlling the operation of 117, the additional folding roller 114 is moved a predetermined number of times N1 along the first fold line 132 with respect to the pedestal portion of the lower folding guide 111 at the pressing position for one fold line ( step S5). Specifically, the control unit 140 drives the additional folding drive motor 128 to horizontally move the support member 112 together with the slider 124 so that one end of the top horizontal portion of the cam groove 131 and the other end of the top horizontal portion of the cam groove 131 move toward the contactor 130 . By repeatedly moving the one-way stroke to and from the end portion N1 times, the additional folding roller 114 is moved N1 times along the first fold line 132 with respect to the pedestal portion of the lower folding guide 111 at the pressing position. Then, additional folding processing is applied to the first fold line 132 .

When the additional folding process for the first fold line 132 is completed, the control unit 140 controls the operation of the first moving mechanism 116 to move the pedestal portion of the lower folding guide 111 as shown in FIG. 8(c). After moving (raising) the plurality of additional folding rollers 114 supported by the support member 112 toward the retracted position by a predetermined distance in a direction away from the sheet S, the sheet S is conveyed downstream (step S6).

The sheet S subjected to the additional folding process for the first fold line 132 is conveyed, and sheet position detection means (not shown) provided upstream of the folding roller pair 105 is used as in the case of the first fold line 132 . ), the controller 140 recognizes that the second fold line 133 has reached the additionally folded portion based on the position of the sheet S detected by ), the control unit 140 changes the position of the sheet S as shown in FIG. is stopped (step S3).

When the second fold line 133 stops at the additionally folded portion, the control unit 140 controls the operation of the first moving mechanism 116 in the same manner as the first fold line 132, and the position shown in FIG. As shown, the plurality of additional folding rollers 114 supported by the support member 112 are moved to the pressing position. After that, the control unit 140 controls the operation of the second moving mechanism 117 to move the additional folding roller 114 along the second fold line 133 with respect to the pedestal portion of the lower folding guide 111 at the pressing position, The second folding line 133 is pressed by the additional folding roller 114 and the base portion of the lower folding guide 111 to strengthen the second folding line 133, that is, perform additional folding.

As in the case of the first fold 132, the control unit 140 controls the operation of the second moving mechanism 117 to move the additional folding roller 114 along the fold at the pressing position. The additional folding roller 114 is moved along the fold with respect to one fold based on whether or not the sheet can be in direct contact with the fold, that is, whether or not the sheet portion is interposed between the additional folding roller 114 and the fold. Change the number of times (step S4).

When the fold line is located below the sheet portion and the sheet portion is interposed between the additional folding roller 114 and the fold line, such as the second fold line 133 on the trailing end side of the sheet S in the conveying direction, the control unit 140 , the operation of the second moving mechanism 117 is controlled to move a plurality of folds supported by the support member 112 along the second fold 133 to the pedestal portion of the lower folding guide 111 at the pressing position for one fold. The additional folding roller 114 is moved by the number of times N2, which is greater than the number of times N1, to perform the additional folding process on the second fold line 133 (step S7). Specifically, the control unit 140 drives the additional folding drive motor 128 to horizontally move the support member 112 together with the slider 124 so that one end of the top horizontal portion of the cam groove 131 and the other end of the top horizontal portion of the cam groove 131 with respect to the contactor 130 . The additional folding roller 114 is moved N2 times along the second fold line 133 with respect to the pedestal portion of the lower folding guide 111 at the pressing position by repeatedly moving the one-way stroke to and from the edge N2 times. Then, additional folding processing is applied to the second fold line 133 .

When the sheet portion is interposed between the additional folding roller 114 and the fold, the pressing force is dispersed by the sheet portion and the pressing force applied to the fold is reduced. However, if the additional folding roller 114 is repeatedly moved along the second folding line 133 at the pressing position for one fold by the number of times N2, which is larger than the number of times N1, the additional folding roller 114 and the lower folding guide 111 are separated. The time to press the sheet portion and the second fold line 133 between the pedestal portion becomes longer, and the sheet portion and the second fold line 133 are given between the additional folding roller 114 and the pedestal portion of the lower side folding guide 111. The total amount of pressing force (work) increases. Therefore, the effect of the decrease in the pressing force applied to the fold by the sheet portion interposed between the additional folding roller 114 and the fold is accompanied by an increase in the number of times the additional folding roller 114 moves along the second fold 133. This is offset by an increase in the total amount of pressing force applied to the sheet portion and the second crease 133 . As a result, the total amount of pressing force applied to the second fold line 133 when the sheet portion is interposed between the additional folding roller 114 and the second fold line 133 causes the additional folding roller 114 and the first fold line 132 to By suppressing the decrease in comparison with the total amount of pressing force applied in direct contact, variation in the additional folding effect due to the positional relationship between the additional folding roller 114, the second fold line 133, and the sheet portion is suppressed. This makes it possible to achieve creases with a more uniform folding height.

Further, in steps S5 and S7, when the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is equal to or greater than a predetermined threshold value α, the control unit 140 When the sheet portion is interposed between the plurality of additional folding rollers 114 and the fold line, the plurality of additional folding rollers 114 are pushed to the second position at the pressing position than when the basis weight of the sheet S is smaller than the predetermined threshold α. The operation of the second moving mechanism 117 may be controlled so as to increase the number of times of movement along the fold line 133 . As a result, the time for pressing the sheet portion and the second fold line 133 between the additional folding roller 114 and the pedestal portion of the lower folding guide 111 becomes longer, and the total amount of pressing force applied to the second fold line 133 ( workload) increases. As a result, in the case of a sheet S such as thick paper that is difficult to fold and has a basis weight equal to or greater than a predetermined threshold value, the effect of strengthening the crease is enhanced, and a more uniform folding height is obtained regardless of the basis weight of the sheet. It becomes possible to realize a crease. When the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is equal to or greater than a predetermined threshold value α, the control unit 140 detects when the sheet portion is interposed between the additional folding rollers 114 and the fold line. In addition, even when the plurality of additional folding rollers 114 face and directly contact the crease, the basis weight of the sheet S acquired by the sheet basis weight detection sensor 141 is smaller than the predetermined threshold value α. Alternatively, the operation of the second moving mechanism 117 may be controlled so as to increase the number of times the additional folding rollers 114 are moved along the folds at the pressing position.

Further, the control unit 140 interposes the sheet portion between the plurality of additional folding rollers 114 and the folds to perform the additional folding processing for the second fold in step S7. When applying a pressing force to the fold between the guide 111 and the pedestal portion, in addition to controlling the number of times of movement along the fold, a plurality of additional folds such as the additional folding processing for the first fold 132 in step S5 are performed. The second moving mechanism 117 is controlled so that the speed of moving the additional folding roller 114 arranged at the pressing position along the fold is slower than when the folding roller 114 is brought into direct contact with the fold and pressed. good too. As a result, the time for pressing the second fold line 133 between the additional folding roller 114 and the pedestal portion of the lower folding guide 111 becomes longer, and the total amount of pressing force applied to the second fold line 133 increases. . Therefore, the effect of the decrease in the pressing force applied to the fold by the sheet portion interposed between the additional folding roller 114 and the fold is accompanied by a decrease in the moving speed of the additional folding roller 114 along the second fold 133. An increase in the total amount of pressing force applied to the sheet portion and the second fold line 133 is also offset. As a result, the total amount of pressing force applied to the second fold line 133 when the sheet portion is interposed between the additional folding roller 114 and the second fold line 133 causes the additional folding roller 114 and the first fold line 132 to Further suppressing reduction compared to the total amount of pressing force applied during direct contact, further suppressing variation in the additional folding effect due to the positional relationship between the additional folding roller 114, the fold line 133, and the sheet portion, The effect of providing folds with a more uniform folding height is enhanced regardless of the positional relationship between the additional folding rollers, the folds, and the sheet portion.

In addition, when the sheet portion is interposed between the additional folding roller 114 and the fold like the second fold 133, the control unit 140 controls the number of times of movement along the fold and also controls the additional folding roller. The first movement is performed so as to increase the pressing force applied to the sheet portion and the fold between the additional folding roller 114 and the pedestal portion of the lower folding guide 111 than when the additional folding roller 114 is in direct contact with the fold. Mechanism 116 may be controlled. As a result, the total amount of pressing force applied to the fold between the additional folding roller 114 and the pedestal portion of the lower folding guide 111 is further increased, so that the sheet is folded between the additional folding roller 114 and the second fold 133 . The total amount of pressing force applied to the second fold line 133 when the part is interposed is reduced compared to the total amount of pressing force applied when the additional folding roller 114 and the first fold line 132 are brought into direct contact. can be further suppressed. Therefore, the variation in the additional folding effect due to the positional relationship between the additional folding roller 114, the fold line 133, and the sheet portion is further suppressed, and the folding height is more uniform regardless of the positional relationship between the additional folding roller, the fold line, and the sheet portion. The effect of providing the crease is enhanced.

When the additional folding process for the second fold line 133 is completed, similarly to the case of the additional folding process for the first fold line 132, the control unit 140 moves the first moving mechanism 116 as shown in FIG. 9(f). After the plurality of additional folding rollers 114 supported by the support member 112 are lifted by a predetermined distance toward the retracted position in the direction away from the pedestal portion of the lower folding guide 111, the sheet S is conveyed downstream. (step S6).

When there are two or more creases such as Z-folding or tri-folding, the operations from step S3 to step S7 are repeated until the additional folding processing for the last crease is completed (step S8). is arranged in the additional folding portion, and a plurality of additional folding rollers 114 are moved along the folds of the sheet S to perform additional folding processing. When the additionally folding process is completed for all folds, the additionally folded sheet S is conveyed to the post-processing apparatus C. As shown in FIG.

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, a guide rail 123, a slider 124, a bracket 125, a pulley 126, a rack 127, an additional folding drive motor 128, a belt 129, a contact 130, a first inclined portion of a cam groove 131 and a second The second moving mechanism 117 includes guide rails 123, sliders 124, brackets 125, pulleys 126, racks 127, additional folding drive motors 128, belts 129, contacts 130, and tops of cam grooves 131. However, if the support member 112 can be moved toward and away from the pedestal portion of the lower folding guide 111 and the support member 112 can be moved along the fold of the sheet S, the first movement mechanism can be used. 116 and the second moving mechanism 117 are 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 can be moved horizontally with respect to the base member 142 , and the base member 142 can be moved up and down by the lifting mechanism 143 to move the support member 112 up and down. In this case, the guide rail 123, the slider 124, the bracket 125, and the linear motion mechanism function as the second movement mechanism, and the lift mechanism 146 functions as the first movement mechanism. Further, in this case, the distance between the support member 112 and the base portion of the lower folding guide 111 at the pressing position can be changed, and the amount of compression of the spring 121 at the pressing position can be changed so that the additional folding roller 114 and the lower folding guide can be folded. It is possible to adjust the pressing force to be applied to the seat S with the pedestal portion 111 . Therefore, as described above, when a sheet portion is interposed between the additional folding roller 114 and the fold like the second fold 133, the control unit 140 causes the additional folding roller 114 to face and directly contact the fold. It is possible to control the first moving mechanism 116 so as to increase the pressing force applied to the sheet portion and the fold between the additional folding roller 114 and the pedestal portion of the lower folding guide 111. .

Furthermore, in the illustrated embodiment, by moving the additional folding roller 114, the additional folding roller 114 is moved with respect to the pedestal portion of the lower folding guide 111. By moving , the additional folding roller 114 may be moved with respect to the base portion of the lower folding guide 111 . Of course, both the additional folding roller 114 and the pedestal portion of the lower folding guide 111 may be moved. Further, instead of the additional folding roller 114 , the pedestal portion of 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 device C Post-processing device 104 Additional folding unit 110 Upper folding guide 111 Lower folding guide 112 Supporting 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 port 121 spring 140 controller 141 sheet basis weight detection sensor

Claims (8)

A sheet folded in a Z -shape by first and second folds formed between a first edge and a second edge opposite the first edge. A sheet pressing device for additionally folding a sheet,
a first portion between the first fold and the second fold; a second portion between the first fold and the first edge; and a second portion between the second edge and the second edge. The folded sheet divided into the third part between the folds is placed on the second part facing the first surface of the first part and the second part on the side opposite to the first surface of the first part. a conveying means that conveys the second portion so that the second portion overlaps the second fold line in a state where the third portion faces the surface;
a pressing roller that rotates around a rotation axis extending in the transport direction of the transport means and presses the folded sheets ;
a facing member arranged to face the pressing roller;
A first position that presses the folded sheet located between the pressing roller and the opposing member , and a second position that moves away from the opposing member in a thickness direction of the sheet pressed at the first position . and a first moving mechanism for moving the pressing roller;
In a state in which the pressing roller is moved to the first position with respect to the facing member by the first moving mechanism, the pressing roller is conveyed so as to press the first fold line or the second fold line. a second moving mechanism for moving along a direction intersecting the direction ;
with
the conveying means conveys the folded sheet such that the second portion of the folded sheet faces the pressing roller and the third portion faces the opposing member;
The second moving mechanism moves the pressing roller more than the number of times the pressing roller moves along the intersecting direction when the first fold is positioned between the pressing roller and the facing member. increasing the number of times that the pressing roller moves along the intersecting direction when the fold is located between the pressing roller and the opposing member ;
A sheet pressing device characterized by : further comprising acquisition means for acquiring basis weight information of the sheet;
The second moving mechanism moves the pressing roller more than the number of times of movement along the intersecting direction when the basis weight of the folded sheet acquired by the acquisition means is smaller than a predetermined basis weight . The basis weight of the folded sheet acquired by the acquiring means is the predetermined
increase the number of times the pressing roller moves along the intersecting direction when the basis weight is equal to or greater than
The sheet pressing device according to claim 1 , characterized in that : The second moving mechanism moves the second fold faster than the pressing roller moves in the intersecting direction when the first fold is positioned between the pressing roller and the opposing member . is positioned between the pressing roller and the opposing member, slowing down the speed at which the pressing roller moves in the intersecting direction ;
3. The sheet pressing device according to claim 1 , wherein : When the second fold is positioned between the pressing roller and the opposing member, the pressing force applied to the folded sheet between the pressing roller and the opposing member is such that the first fold is the stronger than the pressing force applied to the folded sheet between the pressing roller and the opposing member when positioned between the pressing roller and the opposing member ;
The sheet pressing device according to any one of claims 1 to 3 , characterized in that : 5. The sheet pressing device according to claim 1, wherein the second portion of the folded sheet has a larger area than the first portion. The conveying means is a pair of folding rollers for forming the first fold and the second fold on the sheet,
generating the folded sheet by nipping and conveying the sheet by the pair of folding rollers;
The sheet pressing device according to any one of claims 1 to 5, characterized in that: a pair of conveying rollers provided upstream of the pair of folding rollers in the conveying direction for nipping and conveying a sheet;
A first position that allows the pair of conveying rollers to continue conveying the sheet in a state where the pair of folding rollers nips the sheet and stops rotating, thereby forming a loop that hangs down on the sheet, and the loop is formed. a projecting member movable to a second position for projecting a portion of the sheet toward the nip portion of the pair of folding rollers;
7. The sheet pressing device according to claim 6, comprising: an image forming apparatus that forms an image on a sheet;
The sheet pressing device according to claim 6 or 7 , wherein the sheet conveyed from the image forming apparatus is folded .
An image forming system comprising:

Images