JP5151885B2 - Sheet folding device - Google Patents

Description

  The present invention relates to a sheet folding apparatus that performs predetermined sheet folding such as so-called center folding and Z folding.

2. Description of the Related Art Conventionally, a sheet folding apparatus that performs a folding process such as middle folding or Z folding on a sheet on which an image is formed by an image forming apparatus is known.
This sheet folding apparatus includes a folding roller portion in which a pair of rollers are arranged in parallel on one side of the front and back sides of the sheet conveyance path in the middle of the sheet conveyance path so as to be mutually inwardly rotatable with respect to the sheet conveyance path, and between the rollers. And a sheet pushing means for curving the conveyed sheet so that it can be wound up.

  As the conventional sheet folding apparatus described above, a stopper that stops the sheet at a predetermined position by contacting the leading edge of the sheet conveyed to the sheet conveyance path is conveyed from the folding roller unit so as to be able to handle folding of a plurality of sizes. A sheet-shaped folding knife is provided on the downstream sheet conveyance path so that the position can be adjusted, and a plate-like folding knife that pushes the conveyed sheet into the nip is provided so as to be able to advance and retreat at a position facing the nip across the sheet conveyance path ( For example, see Patent Document 1).

  As another example, a pair of rollers is provided with a driven roller across the sheet conveyance path, and a pair of rollers including a roller and a driven roller that rotates with the roller is provided so as to be able to contact and separate. There is a type in which a sheet that has been conveyed by bending a pair of rollers from a state where they are separated from each other is bent and bent toward a nip (see, for example, Patent Document 2).

  As still another example, an arm-shaped guide that is provided with a driven roller for each of a pair of rollers across the sheet conveying path, and swings with the center of the driven roller on the downstream side of the sheet conveying as a rocking fulcrum and moves toward and away from the nip. There is a member provided with a member, and the conveyed sheet is pushed toward the nip by the guide member (for example, see Patent Document 3).

Japanese Utility Model Publication No. 4-117869 JP 2004-338918 A JP 2005-8337 A

However, these sheet folding apparatuses described above have the following problems.
The sheet folding apparatus described in Patent Document 1 and Patent Document 3 moves the folding knife unit or the arm-shaped guide member waiting above the sheet conveying path so as to abut against the conveyed sheet, and the folding roller unit Therefore, depending on the type of paper (sheet), the sheet may be damaged.

  The sheet folding apparatus described in Patent Document 2 has a configuration in which a pair of rollers are brought into contact with and separated from each other, and the conveyed sheet is bent and held in the nip. Depending on the type, size, environment, and the like of the sheet, the bending shape of the sheet changes and the folding position is likely to vary, and the quality is not stable.

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a sheet folding apparatus that improves the quality of sheet folding while wiping out the possibility of breakage of the sheet.

In order to achieve the above technical problem, the present invention has taken the following technical means.
The invention according to claim 1 is composed of a pair of folding rollers that can rotate inward with respect to the sheet conveyance path, and a folding roller portion in which a nip is formed by the pair of folding rollers is disposed in the sheet conveyance path, In the sheet folding apparatus for folding a sheet, the sheet folding unit includes a sheet pushing unit that curves the sheet conveyed to the sheet conveyance path so as to be wound into the nip, and the pushing unit is one of the folding rollers of the folding roller unit. A pressing roller disposed on the sheet conveying path side, and a pressing roller moving unit that moves the pressing roller toward and away from the nip along the circumferential surface of one of the folding rollers. The invention according to claim 2 is characterized in that, in claim 1, the pushing roller moving means includes the pushing roller. The one of the folding rollers is supported so as to be driven to rotate, and the pushing roller is configured to be swingable along the sheet conveying path side peripheral surface of any one of the folding rollers.
According to a third aspect of the present invention, in the first or second aspect, the push-in roller is disposed on a folding roller on the upstream side of sheet conveyance among the pair of folding rollers.
According to a fourth aspect of the present invention, there is provided the sheet folding apparatus according to any one of the first to third aspects, wherein the outer peripheral surface of the pair of folding rollers on the downstream side of the sheet conveyance has low friction. Features.
According to a fifth aspect of the present invention, when the sheet folding presence / absence signal transmitted from the outside is received according to any one of the first to fourth aspects and the sheet folding presence / absence signal is sheet folding, the push roller When the sheet folding is executed by operating the moving means, and the sheet folding presence / absence signal is not sheet folding, the conveyed sheet can be sent to the downstream of the sheet conveying path from the folding roller unit. Control means for maintaining the execution state is provided.
According to a sixth aspect of the present invention, in any one of the first to fifth aspects, a guide plate that guides the sheet is provided on a side facing the folding roller portion with the sheet conveyance path interposed therebetween, and the pair of folding sheets is provided. Among the rollers, the folding roller on the downstream side of the sheet conveyance is provided at a position farther from the guide plate than the folding roller on the upstream side of the sheet conveyance.
According to a seventh aspect of the present invention, in any one of the first to sixth aspects, when the sheet folding presence / absence signal transmitted from the outside is received and the sheet folding presence / absence signal is sheet folding, the push roller When the sheet folding is performed by operating the moving means and the sheet folding presence / absence signal is not sheet folding, the conveyed sheet is separated from the folding roller on the downstream side of the sheet conveyance of the pair of folding rollers. Control means for moving the pushing roller by operating the pushing roller moving means so as to be capable of being fed in the direction of movement is provided.
An invention according to an eighth aspect is the invention according to any one of the first to seventh aspects, wherein the pushing roller moving means presses the pushing roller against the one of the folding rollers, and the pressing force can be varied. It is characterized in that the pressing force is different between when the sheet is folded and when the sheet is not folded.
According to a ninth aspect of the present invention, in any one of the first to eighth aspects, the pushing roller moving means presses the pushing roller against the one of the folding rollers, and also pushes the pushing roller into the nip. It is characterized in that the pressing force increases as it moves.
A tenth aspect of the present invention is the sheet detection unit according to any one of the first to ninth aspects, wherein the sheet detection unit is provided upstream of the folding roller unit to detect the sheet being conveyed, and the sheet detection unit. Control means for adjusting the folding position by variably controlling the time from the detection of the sheet by the start of execution of sheet folding.

  According to the present invention, the sheet pressing means that curves the conveyed sheet so that it can be wound into the nip of the folding roller portion can be moved closer to the nip and separated from the nip so as to follow any one of the folding rollers. When the sheet is folded, the knife or the arm-shaped guide member is not abutted against the conveyed sheet when the sheet is folded. Further, since the pushing roller is moved so as to be separated to the nip along one of the folding rollers and the sheet folding operation is performed, there is no variation in folding position, and stabilization of quality can be expected.

An embodiment of the present invention will be described.
As shown in FIG. 1, a sheet folding apparatus A according to the present embodiment is provided between an image forming apparatus B such as a copying machine and a sheet post-processing apparatus C that performs post-processing such as stapling and punching on a sheet. The sheet (paper) can be received from the image forming apparatus B and the sheet S can be transferred to the sheet post-processing apparatus C. From the image formation to the sheet to sheet folding, stapling and punching is consistently performed. It is built into a processable image forming system. Hereinafter, each embodiment of sheet folding of the sheet folding apparatus A, which is the main part of the present invention, will be described in detail. For convenience, the same reference numerals are used for the sheet folding apparatuses of the embodiments.

(Embodiment 1)
In FIG. 1, the sheet folding apparatus A according to the first embodiment includes a casing 1, a folding roller unit 2, a sheet pushing means 3, and a control means (not shown).

  The casing 1 includes an outer frame 1a that forms the appearance of the sheet folding apparatus A, and an inner frame 1b (FIG. 3) that is provided inside the outer frame 1a and supports each mechanism unit. 2, seat pushing means 3, control means and the like are provided.

  In FIG. 2, a horizontal sheet conveyance in which the sheet S from the image forming apparatus B is received from one side of the casing 1 and the sheet S is transferred to the sheet post-processing apparatus C from the other side in FIG. A path c1 is formed. The sheet conveyance path c1 includes a sheet guide guide plate c3 that is appropriately provided in the vertical direction with a predetermined interval, a conveyance roller c4 that conveys the sheet S from right to left in FIG. It is formed with.

  In the middle of the sheet conveyance path c1, a sheet conveyance path c2 through which the sheet S folded in half from a folding roller section 2 described later is provided. In the middle of the sheet conveyance path c2, a sheet conveyance path c6 that reverses the conveyance direction of the sheet S when the folded sheet S is further Z-folded in FIG. 1 via the conveyance path switching claw c5. The conveyance path of the sheet S is switched in the downstream direction of the sheet conveyance path c2 or the direction of the sheet conveyance path c6 by swinging the conveyance path switching claw c5.

A folding roller section 2 for Z-folding is provided on the downstream side in the transport direction of the sheet transporting path c2 from the transporting path switching claw c5, and the sheet S that has been Z-folded by the folding roller section 2 for Z-folding is provided. A sheet conveyance path c7 to be conveyed is provided. The sheet conveyance path c2 and the sheet conveyance path c7 finally merge with the sheet conveyance path c1 that is transferred to the sheet post-processing apparatus C.
In the case of Z-folding, the folding roller unit 2 for middle folding, which is the first folding roller unit, is folded once except for the center of the sheet S (for example, folded from 1/3 of the sheet S), and then Z-folding is possible by reversing the conveying direction of the sheet S and folding the center of the sheet S, for example, with the folding roller unit 2 for Z-folding, which is the second folding roller unit, from the direction opposite to the direction of the middle folding. It is.
As described above, although there are two folding rollers 2 and sheet pushing means 3 for the middle folding and for the Z folding (both have the same configuration), for the convenience of explanation, the explanation will be made below by taking the middle folding as an example. .

  In FIG. 2, the folding roller unit 2 is disposed below the middle part of the sheet conveyance path c1 (the sheet back side perpendicular to the sheet conveyance direction), and a pair of folding rollers 21a and 21b that are in contact with each other to form a nip N; A drive motor (not shown) is configured to rotate the pair of folding rollers 21a and 21b inward with respect to the sheet conveyance path c1. The pair of folding rollers 21a and 21b is pivotally supported on the inner frame 1b so that the sheet can be conveyed. The folding roller unit 2 folds the sheet by sandwiching the conveyed sheet S in the nip N.

  The folding rollers 21a and 21b have different arrangement heights. That is, the folding roller 21a on the upstream side of the sheet conveyance is disposed so that the highest part of the outer circumferential surface of the folding roller (the outer circumferential surface portion directly above the axis) is flush with the lower surface of the sheet conveyance path c1. The folding roller 21b on the downstream side of the sheet conveyance is disposed at a position separated from the guide plate c3 above the folding roller 21a on the upstream side of the sheet conveyance so as to be lower than the folding roller 21a on the upstream side of the sheet conveyance. Has been.

  As described above, the folding roller 21b on the downstream side of the sheet conveyance is disposed lower than the folding roller 21a on the upstream side of the sheet conveyance, so that the folding roller 21b on the downstream side of the sheet conveyance that rotates in the direction opposite to the conveyance direction of the sheet S is provided. However, it does not become a resistance at the time of sheet conveyance in a process in which the middle folding is not executed. Further, the outer peripheral surface of the folding roller 21b on the downstream side of the sheet conveyance may be configured to have low friction. In this case, the arrangement height of the pair of folding rollers 21a and 21b can be made uniform.

  The sheet pushing means 3 includes a pushing roller moving means 31 and a pushing roller 32, and the pushing roller moving means 31 includes a drive unit, a swing arm 35, and an idle gear 36.

  The driving unit is located in the vicinity of the sheet conveyance upstream side of the lowest outer peripheral surface portion (the outer peripheral surface portion immediately below the shaft center) of the folding roller 21a on the upstream side of the sheet conveyance, and on the inner side of one of the folding rollers. A drive motor (not shown) attached to the frame 1b and capable of controlling the rotation angle, and a drive gear 34 composed of a small-diameter gear attached to a rotation shaft 33 of the drive motor are provided.

The swing arm 35 is a half-moon-shaped support portion 35a that is pivotally supported by the shaft end of the folding roller 21a on the upstream side of the sheet conveyance, and extends radially from the support portion 35a, and is outside the outer peripheral surface of the folding roller 21a. The arm portion 35b has a bearing 35c that supports a push roller 32 described later on the top portion.
The swing arm 35 is a sector gear by cutting the same module as the drive gear 34 only on the outer peripheral surface of the support portion 35a disposed on the drive portion side.

The idle gear 36 is a gear having a required diameter formed by the same module as that of the drive gear 34, and is pivotally supported on the inner frame 1 b so as to mesh with both the sector gear and the drive gear 34 described above.
The pushing roller moving means 31 configured as described above is a gear train including an idle gear 36, a sector gear, and a drive gear 34, and reduces the rotational speed of the rotational shaft 33 of the drive motor to a predetermined rotational speed. The swing arm 35 can be moved toward and away from the nip N by swinging at a predetermined speed.

  Each inner frame 1b on both ends of the push roller 32 is formed with a stopper groove 1c in which the guide shaft portion 32b of the push roller 32 is loosely fitted. The stopper groove 1c is formed in an arc shape centering on the axial center of the folding roller 21a on the upstream side of the sheet conveyance, and restricts the swing range of the pushing roller 32 inside both ends thereof.

The pushing roller 32 has a length substantially the same as the length of the folding roller and has a smaller diameter than the pair of folding rollers 21a and 21b, and extends from both ends of the pressing portion 32a and is reduced in diameter by the pressing portion 32a. The guide shaft portion 32b is formed in a stepped round shaft shape.
As shown in FIGS. 2 and 3, the pushing roller 32 formed in this way has guide shaft portions 32b loosely inserted in the stopper grooves 1c and bearings 35c of the arm portions 35b disposed at both ends of the rollers. The guide shaft portion 32b is pivotally supported by the swing arm 35 so that the outer peripheral surface of the push-in roller 32 is in contact with the outer peripheral surface of the folding roller 21a on the upstream side of sheet conveyance.

  The sheet pushing means 3 configured as described above is configured so that the pushing roller 32 is driven and rotated by the rotation of the folding roller 21a on the upstream side of the sheet conveyance, and the rotation shaft 33 of the drive motor rotates in the forward and reverse directions. The push-in roller 32 swings along the upper outer peripheral surface of the folding roller 21a on the upstream side of sheet conveyance via the train and swing arm 35.

  In FIG. 1, the control means is electrically connected to each of the mechanical units constituting the sheet folding apparatus A, the image forming apparatus B, and the sheet post-processing apparatus C, and the sheet folding from the image forming apparatus B side. In response to a presence / absence signal or the like, an operation signal can be output to each mechanism part of the sheet folding apparatus A according to a predetermined control program, and the sheet post-processing apparatus C disposed on the downstream side of the sheet conveyance can be electrically It is configured to output a typical signal. The sheet folding presence / absence signal is a sheet folding execution signal or a middle folding execution signal or a Z folding execution signal.

This control means includes a non-contact type sheet detection sensor 4 as a sheet detection means for detecting the conveyed sheet S. The sheet detection sensor 4 is upstream of the sheet conveyance from the folding roller 21a on the upstream side of the sheet conveyance. On the side.
Note that the control related to sheet folding is replaced with the following series of operation descriptions.

  Next, a series of operations of the sheet folding apparatus A according to the first embodiment configured as described above will be described.

  When the sheet folding presence / absence signal for the sheet S received from the image forming apparatus B indicates that the sheet is folded, the control means uses the time when the sheet S is detected by the sheet detection sensor 4 as a time measurement start point, and the elapsed time from the start point. Based on the time and the sheet speed of the sheet conveyance path c1, the rotation of the folding roller 21a on the upstream side of the sheet conveyance is controlled to feed the sheet S by a predetermined amount. At this time, the push-in roller 32 is positioned at or near the highest portion of the outer peripheral surface of the folding roller 21 a on the upstream side of the sheet conveyance, and is driven to rotate via the sheet S.

  This control means can variably control the time from the sheet detection by the sheet detection sensor 4 to the start of sheet folding, and by changing the sheet feed amount according to the sheet size and the folding position desired by the user. The folding position can be adjusted.

  As soon as the predetermined sheet feed amount is reached, the rotation shaft 33 of the drive motor starts to rotate counterclockwise in FIG. 2 by a predetermined rotation angle, via the gear train and the swing arm 35. The pushing roller 32 moves in the nip N direction along the upper outer peripheral surface of the folding roller 21a.

  Along with the movement of the pushing roller 32, a part of the sheet S sandwiched between the pushing roller 32 and the folding roller 21a on the upstream side of the sheet conveyance and its surrounding portion are curved toward the nip N, and As the folding roller 21a rotates, the sheet S is sandwiched in the nip N with the scheduled folding position of the sheet S at the head, whereby the sheet folding starts (see FIG. 4).

  When the sheet S passes through the nip N, the pushing roller 32 stands by at the highest portion of the outer peripheral surface of the folding roller 21a by the operation opposite to the operation of the pushing roller moving unit 31. On the other hand, the sheet S that has been folded in half is sent to the sheet conveyance path c2 starting from the exit of the nip N. At this time, the conveyance path switching claw c5 (FIG. 1) moves the sheet S in the downstream direction of the sheet conveyance path c2 or in the direction of the sheet conveyance path c6 based on whether the folding signal is the middle folding execution signal or the Z folding execution signal. Rocks.

In FIG. 1, in the case of an intermediate folding execution signal, the sheet S passes through the Z-folding folding roller section 2 and the sheet pushing means 3, and moves to the sheet post-processing apparatus C via the sheet conveyance path c1.
In the case of the Z-fold execution signal, the sheet S temporarily moves in the direction of the sheet conveyance path c6, and reverses the conveyance direction, and moves toward the Z-folding folding roller section 2 and the sheet pushing means 3. Then, the folding roller section 2 for Z folding and the sheet pushing means 3 Z-folds the sheet S that has been folded in the same manner as the above-described middle folding, and sends it out to the sheet conveying path c7. Then, the sheet is moved to the sheet post-processing apparatus C via the sheet conveyance path c1.

  In addition, when the sheet folding presence / absence signal for the sheet S received from the image forming apparatus B is not sheet folding, the control unit does not execute the sheet folding operation and maintains the non-executed state of the sheet folding. A sheet without folding is delivered to the sheet post-processing apparatus C via the conveyance path c1.

  As described above, in the sheet folding apparatus A according to the first embodiment, the sheet pushing means 3 that pushes the sheet S into the folding roller portion 2 in which the pair of folding rollers 21a and 21b are arranged side by side is provided on the folding roller 21a on the upstream side of the sheet conveyance. Therefore, when the sheet is folded, the pushing roller 32 is moved toward the nip N so that the pushing roller 32 can move toward and away from the nip N. Can eliminate the fear of doing. Further, since the pushing roller 32 is moved to the nip N so as to be separated along the folding roller 21a on the upstream side of the sheet conveyance, and the sheet folding operation is performed, there is no variation in the folding position, and stabilization of quality can be expected. .

  Further, since the space for disposing the sheet pushing means 3 does not require a disposing space extending in the front and back direction of the sheet unlike the folding knife type sheet pushing means 3, the apparatus can be expected to be downsized.

  Further, by arranging the folding roller 21b on the downstream side of the sheet conveyance lower than the folding roller 21a on the upstream side of the sheet conveyance, the folding roller 21b on the downstream side of the sheet conveyance that rotates in the direction opposite to the conveyance direction of the sheet S is Since there is no resistance at the time of sheet conveyance in the sheet folding-free process, there is very little variation in folding position, and the sheet can be folded with high accuracy.

  In this embodiment, the sheet folding apparatus A of both the middle folding and Z folding type is illustrated, but the sheet conveying path c6, the folding roller portion 2 for Z folding, and the sheet pushing means 3 are eliminated, It is good also as a structure only for folding.

  In the first embodiment, the stopper groove 1c is provided to prevent the overrun of the push-in roller 32, and the guide shaft portion 32b is inserted into the stopper groove 1c. However, as shown in FIG. The forward end stopper 1e and the reverse end stopper 1f may be protruded from the inner frame 1b so as to be engageable with the push-in roller 32.

(Embodiment 2)
A sheet folding apparatus A according to the second embodiment shown in FIG. 5 is a modification of the sheet pushing means 3 illustrated in the first embodiment, and substantially the same components as those in the first embodiment are the same as those in the first embodiment. The same reference numerals are used and the description thereof is omitted.

  The sheet pushing means 5 according to the second embodiment includes a pushing roller moving means 51 and a pushing roller 52.

  The pushing roller moving means 51 includes a swing link portion and a plate cam portion.

  The swing link portion is formed in a belt plate shape whose base end is pivotally supported at a predetermined position above the nip N of the inner frame 1b and extends toward the folding roller 21a on the upstream side of the sheet conveyance, and in the longitudinal direction. A link 53 formed with a slot-like slide hole 53a, a slide piece 54 slidably engaged with the slide hole 53a and disposed at the free end of the link 53, the slide piece 54 and the slide hole A compression spring 55 that is stretched between the link 53 base end side of 53a and urges the slide piece 54 in the direction of the folding roller 21a on the upstream side of the sheet conveyance; and a folding roller on the upper side surface of the link 53 on the upstream side of the sheet conveyance A tension spring 56 having one end fastened to the side 21a and the other end fastened to the inner frame 1b is provided. The swing link portions are provided on both ends of the folding roller 21a on the upstream side of sheet conveyance.

  The plate cam portion is provided on a drive motor (not shown) capable of controlling the rotation angle provided at a predetermined position above the folding roller 21a on the upstream side of the sheet conveyance of the inner frame 1b, and a rotation shaft 57 of the drive motor. A plate cam 58 that is fixed and abuts the upper surface of the link 53 and that can push the free end side of the link 53 in the direction of the nip N is provided.

The pushing roller 52 is substantially the same length as the folding roller and has a smaller diameter than the folding roller, a pressing portion 52a, a guide shaft portion 52b extending from both ends of the pressing portion 52a and having a smaller diameter than the pressing portion 52a, and its guide. The support shaft portion 52c extending from the shaft portion 52b forms a stepped round shaft.
As shown in FIGS. 6 and 7, the pushing roller 52 formed in this way has guide shaft portions 52b loosely inserted into the arc-shaped stopper grooves 1c and swing links provided at both ends of the roller. The support shaft portion 52c is pivotally supported by the slide piece 54, and the outer peripheral surface of the push-in roller 52 is supported by the swing link portion so as to be in contact with the outer peripheral surface of the folding roller 21a on the upstream side of sheet conveyance. Yes.

  In the sheet pushing means 5 configured as described above, the pushing roller 52 is driven to rotate by the rotation of the folding roller 21a on the upstream side of the sheet conveyance, and the plate cam 58 is rotated forward and backward via the rotation shaft 57 of the drive motor. As a result, the link 53 swings due to the pressing force of the plate cam 58 and the tensile force of the tension spring 56, and the pressing roller 52 urged by the compression spring 55 is accompanied by the folding roller on the upstream side of the sheet conveyance. It swings along the upper outer peripheral surface of 21a.

  When the pushing roller 52 moves toward the nip N direction from the position of the highest part of the outer peripheral surface of the folding roller 21a on the upstream side of the sheet conveyance or in the vicinity thereof, the link support position of the link 53 and the center of the pushing roller 52 are connected. As the distance is reduced and the compression spring 55 is contracted, the pressing force applied to the folding roller 21a on the upstream side of the sheet conveyance by the pushing roller 52 is pushed toward the folding roller 21a on the upstream side of the sheet conveyance as it moves toward the nip N. The power is getting bigger. The pressing force can be changed by changing the shaft support position of the link 53.

  In the sheet folding apparatus A according to the second embodiment configured as described above, the sheet folding presence / absence signal for the sheet S received from the image forming apparatus B is similar to the series of operations by the control unit exemplified in the first embodiment. When the sheet is folded, the push roller 52 is moved in the direction of the nip N and the sheet S is folded from a predetermined position as shown in FIG. If the sheet folding presence / absence signal indicates that there is no sheet folding, the sheet folding operation is not executed, the non-executed state of the sheet folding is maintained, and the unfolded sheet is sent to the sheet post-processing apparatus C via the sheet conveyance path c1. Deliver.

According to the sheet folding apparatus A according to the second embodiment, in addition to the effects of the first embodiment, the pressing roller 52 is urged by the compression spring 55 so that the pressing roller 52 folds the sheet conveyance upstream side. The pressing force to the roller 21a can be set to an optimal pressing force when the sheet is folded.
In addition, since the pressing force of the pressing roller 52 against the folding roller 21a of the sheet S increases as it moves toward the nip N, the sheet S is surely guided to the nip N, and an accurate folding position is achieved. Can be obtained.

  As described above, in the second embodiment, the compression spring 55 is used to change the pressing force of the pressing roller 52 against the folding roller 21a on the upstream side of the sheet conveyance. The shape of the bearing 35c of the exemplified swing arm 35 is, for example, a U-shaped (or elongated hole) bearing 35d as shown in FIG. On the other hand, instead of the stopper groove 1c illustrated in the first embodiment, the stopper groove 1c is formed so as to slightly approach the outer peripheral surface of the folding roller 21a on the upstream side of the sheet conveyance as it approaches the nip N, and can guide the pushing roller 32. The groove 1d may be used to be displaced in the radial direction simultaneously with the circumferential swing of the push-in roller 52.

(Embodiment 3)
In the first and second embodiments, the arrangement position of the folding roller 21b on the downstream side of the sheet conveyance that rotates in the direction opposite to the conveyance direction of the sheet S is lowered from the folding roller 21a on the upstream side of the sheet conveyance, thereby Although an example in which the conveyance resistance is prevented is shown, the sheet folding apparatus A according to the third embodiment uses the sheet pushing means 3 and 5 according to the first or second embodiment, and a pushing roller by a control means (not shown). 32 and 35 are controlled to change the sheet feeding direction.

  The third embodiment shown in FIG. 10 will be described by taking the sheet pushing means 3 exemplified in the first embodiment as an example. In the third embodiment, the sheet folding presence / absence signal transmitted from the image forming apparatus B is a sheet folded. In this case, the control means moves the push roller 32 in the direction of the nip N to execute the sheet folding. However, when the sheet is fed before the sheet folding is performed, the control means performs the folding roller 21a and the push roller on the upstream side of the sheet conveyance. Immediately after the sheet S enters between 32 and 32, the highest part of the outer peripheral surface of the folding roller 21a on the upstream side of the sheet conveyance (the outer peripheral surface portion directly above the axis) or its vicinity so that the sheet S is sent out upward The pushing roller 32 is moved further to the upstream side in the conveyance direction, and the sheet S is separated from the folding roller 21b on the downstream side of the sheet conveyance to perform sheet feeding. This operation is the same when the sheet folding presence / absence signal is “no sheet folding”, and prevents sheet conveyance resistance from being generated by the folding roller 21b on the downstream side of sheet conveyance.

  According to the third embodiment, as in the first and second embodiments, the arrangement position of the folding roller 21b on the downstream side of the sheet conveyance that rotates in the direction opposite to the conveyance direction of the sheet S is set to the folding position on the upstream side of the sheet conveyance. The folding roller 21b on the downstream side of the sheet conveyance can be arranged at the same height level as the folding roller 21a on the upstream side of the conveyance of the sheet. Further, since the position of the push roller 32 is controlled so that the sheet S is sent upward, the separation distance between the folding roller 21b on the downstream side of the sheet conveyance and the sheet S can be easily changed.

(Embodiment 4)
In each of the above-described embodiments, the sheet pressing unit 3 is engaged with the folding roller 21a on the upstream side of the sheet conveyance. However, the sheet folding apparatus A according to the fourth embodiment shown in FIG. In this example, the sheet pushing means 3 is engaged with the folding roller 21b on the downstream side, and the same components as those in the above-described embodiments are denoted by the same reference numerals and detailed description thereof is omitted.

  As shown in FIG. 11, the configuration shown in FIG. 5 in the first embodiment is an example of diverting to the folding roller 21 b side on the downstream side of the sheet conveyance. In this case, when the sheet is folded or when the sheet is simply passed without being folded, the push roller 32 interferes with the conveyance of the sheet S. Therefore, instead of the arm portion 35b illustrated in the first embodiment, the folding roller A linear actuator 35d such as a solenoid provided with a rod 35e capable of moving back and forth in the radial direction 21b is provided, and a bearing 35c is provided at the tip of the rod 35e so that the pushing roller 32 is an outer peripheral surface of the folding roller 21b on the downstream side of the sheet conveyance It is configured to be able to contact and separate.

(Embodiment 5)
As shown in FIG. 12, the fifth embodiment is an example in which the configuration of the second embodiment shown in FIG. 6 is diverted to the folding roller 21b side on the downstream side of sheet conveyance. In this case, instead of the stopper groove 1c provided for preventing the overrun of the push-in roller 32, the forward end stopper 1e is configured so as to be able to contact and separate from the outer peripheral surface of the folding roller 21b on the downstream side of the sheet conveyance.

Thus, the sheet pushing means 3 according to the present invention can be engaged with either the folding roller 21a on the upstream side of sheet conveyance or the folding roller 21b on the downstream side of sheet conveyance.
Further, although the folding roller unit 2 is illustrated as being disposed below the middle part of the sheet conveyance path c1, it is not limited to this and may be disposed on the sheet front side of the sheet conveyance path c1.

  As mentioned above, although the sheet folding apparatus concerning this Embodiment was demonstrated, each embodiment shows an example of the suitable embodiment of this invention, This invention is not limited to it, The Various modifications can be made without departing from the scope of the invention.

1 is a schematic view of an image forming system provided with a sheet folding apparatus according to the present embodiment. FIG. 3 is a front view of a main part of the sheet folding apparatus according to the first embodiment. FIG. It is the front view of the principal part which showed the operation state following FIG. FIG. 10 is a front view of a modification of the first embodiment. FIG. 6 is a front view of a main part of a sheet folding apparatus according to a second embodiment. FIG. It is a front view of the principal part which showed the operation state following FIG. FIG. 6 is a front view showing a modification of the first embodiment. FIG. 6 is a front view of a main part of a sheet folding apparatus according to a third embodiment. It is a front view of the principal part of the sheet folding apparatus concerning Embodiment 4. FIG. 10 is a front view of a main part of a sheet folding apparatus according to a fifth embodiment.

Explanation of symbols

A Sheet folding device B Image forming device C Sheet post-processing device c1, c2 Sheet conveying path c3 Guide plate c4 Conveying roller N Nip 1 Case 1a Outer frame 1b Inner frame 1c Stopper groove 2 Folding roller portion 21a Folding of sheet conveying upstream side Roller 21b Folding roller on the downstream side of sheet conveyance 3 Sheet pushing means 31 Moving means 32 Pushing roller 32a Pressing part 32b Guide shaft part 32c Support shaft part 33 Rotating shaft 34 Small diameter gear 35 Swing arm 35a Supporting part 35b Arm part 35c Bearing 36 Idle gear 4 Sheet detection sensor 5 Sheet pushing means 51 Moving means 52 Pushing roller 52a Pressing portion 52b Guide shaft portion 52c Support shaft portion 53 Link 53a Slide hole 54 Slide piece 55 Compression spring 56 Pulling spring 57 Rotating shaft 58 Plate cam

Claims (10)

In a sheet folding apparatus comprising a pair of folding rollers that can rotate inward with respect to the sheet conveying path, a folding roller part that forms a nip with the pair of folding rollers is disposed in the sheet conveying path, and the sheet is folded at the nip.
A sheet pushing means for curving the sheet conveyed to the sheet conveyance path so as to be wound around the nip;
The pushing means is
A pressing roller disposed on the sheet conveying path side of any one of the folding rollers; and
A pushing roller moving means for moving the pushing roller in the approaching and separating directions with respect to the nip along the circumferential surface of the one of the folding rollers;
A sheet folding apparatus comprising:   The pushing roller moving means supports the pushing roller so as to be driven and rotated by any one of the folding rollers, and can swing the pushing roller along the sheet conveyance path side peripheral surface of any one of the folding rollers. The sheet folding apparatus according to claim 1, wherein the sheet folding apparatus is configured as described above.   3. The sheet folding apparatus according to claim 1, wherein the push-in roller is disposed on a folding roller on the upstream side of sheet conveyance among the pair of folding rollers.   4. The sheet folding apparatus according to claim 1, wherein an outer peripheral surface of the pair of folding rollers on the downstream side of the sheet conveyance has low friction. 5.   When a sheet folding presence / absence signal transmitted from the outside is received and the sheet folding presence / absence signal is sheet folding, the push roller moving means is operated to execute sheet folding, and the sheet folding presence / absence signal is 2. The apparatus according to claim 1, further comprising a control unit that maintains a non-executed state of sheet folding so that the sheet that has been conveyed can be fed downstream from the folding roller unit to a sheet conveying path when there is no folding. The sheet folding apparatus according to any one of 4.   A guide plate that guides the sheet is provided on the side facing the folding roller portion across the sheet conveyance path, and the folding roller on the downstream side of the sheet conveyance among the pair of folding rollers is the folding roller on the upstream side of the sheet conveyance The sheet folding apparatus according to claim 1, wherein the sheet folding apparatus is provided at a position further away from the guide plate.   When a sheet folding presence / absence signal transmitted from the outside is received and the sheet folding presence / absence signal is sheet folding, the push roller moving means is operated to execute sheet folding, and the sheet folding presence / absence signal is In the case of no folding, the moving means is operated to move the push roller so that the conveyed sheet can be sent out in a direction away from the folding roller on the downstream side of sheet conveyance among the pair of folding rollers. The sheet folding apparatus according to claim 1, further comprising a control unit.   The push roller moving means is configured to press the push roller against any one of the folding rollers and to change the pressing force so that the sheet is folded and when the sheet is not folded. The sheet folding apparatus according to any one of claims 1 to 7, wherein the pressing force is varied.   2. The pressing roller moving means is configured to press the pressing roller against one of the folding rollers and to increase the pressing force as the pressing roller moves to the nip. The sheet folding apparatus according to any one of 1 to 8.   Provided on the upstream side of the sheet conveyance from the folding roller unit, and a sheet detection means for detecting the sheet being conveyed, and the time from the detection of the sheet by the sheet detection means to the start of sheet folding is controlled to be variable The sheet folding apparatus according to claim 1, further comprising a control unit that adjusts a folding position.

Images