JP2020172399A - Sheet processing device and image formation system - Google Patents

Abstract

To provide a sheet processing device that can shorten a time from the application of liquid onto a sheet to the crimping.SOLUTION: The sheet processing device that performs binding processing on a sheet bundle comprised of multiple sheets includes: application means that applies liquid onto a sheet; and binding processing means that binds the sheet bundle. The application means applies the liquid onto the outermost sheet of the sheet bundle, and the static surface tension of the liquid is smaller than the static surface tension of water. The binding processing means has a pair of compression teeth, and the compression teeth hold and compress the sheet bundle. On the sheet bundle, a liquid application area where the liquid is applied and a compression area that is compressed by the compression teeth are provided in an overlapping manner.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sheet processing apparatus and an image forming system that perform a binding process on a sheet.

Conventionally, in an image forming apparatus such as a copier, a laser beam printer, a facsimile, or a multifunction device thereof, a sheet on which an image is formed is conveyed and placed on a processing tray, and a binding process is performed on the placed sheet bundle. There is a sheet processing device having a unit.

In such a device, from the viewpoint of labor saving and environmental protection, there is known a device in which sheets are crimped to each other without using a metal needle as a binding member. In this so-called crimp binding, a load is applied to the pressure teeth in which a pair of uneven teeth are meshed with the overlapping sheets, and the fibers of the sheets are entwined and bound.

With this crimp binding, the sheet can be bound without using a needle, but if the number of sheets is several, crimp bonding is possible, but if the number of sheets is large, the uneven pressure teeth (pressurized teeth and receiver) The teeth) became difficult to fit and the fastening force was weakened.

In order to strengthen this fastening force, Patent Document 1 describes a sheet when crimping with an upper mold (upper pressure tooth) having triangular irregularities and a lower mold (lower pressure tooth) that meshes with the upper mold (upper pressure tooth). It is described that a lump of water is applied to the surface of the bundle and then crimped.

Further, Patent Document 2 describes that before crimping sheets made of paper to each other, water is added to facilitate entanglement of the fibers of the sheets. It is also described that water is supplied along the edge of the sheet during transportation of the sheet.

Further, Patent Document 3 describes that water is added to the binding area of the sheet for pressure-bonding, and an inkjet head that discharges water from the nozzle hole is used as the water addition mechanism. It is also described that the pressure bonding strength is changed by changing the amount of water added.

Further, in Patent Document 4, when the number of sheets to be placed is several (between 2 and 6), a normal crimping operation is performed without adding water, and when the number exceeds the above number, the crimping range is set. It is described that the pressure is applied after adding water.

Patent No. 3481300 Patent No. 3502204 JP-A-2014-201432 JP-A-2018-199553

However, neither document mentions a configuration that shortens the time for the liquid to permeate the sheet and shortens the time from application of the liquid to the sheet to pressure bonding.

An object of the present invention is to provide a sheet processing apparatus and an image forming system capable of shortening the time from application of a liquid to a sheet to pressure bonding.

The sheet processing apparatus according to the present invention is a sheet processing apparatus including a applying means for applying a liquid to a sheet and a binding processing means for binding a sheet bundle, and performing a binding process on the sheet bundle composed of a plurality of sheets. The applying means applies the liquid to the outermost sheet of the sheet bundle, the static surface tension of the liquid is smaller than the static surface tension of water, and the binding processing means is a pair. A pressure tooth is provided, and the pressure tooth holds and pressurizes the sheet bundle, and in the sheet bundle, a liquid application region to which the liquid is applied and a pressure applied by the pressure tooth. The regions are characterized in that they are provided in an overlapping manner.

According to the present invention, the time from application of the liquid to the sheet to pressure bonding can be shortened.

It is a figure which shows the area around a processing tray and a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of a binding unit. It is a figure for demonstrating the structure of the replacement fluid pump unit. It is a figure for demonstrating the structure of the replacement fluid pump unit. It is a figure for demonstrating the structure of the replacement fluid pump unit. It is a figure for demonstrating the operation of applying a liquid and crimping. It is a figure for demonstrating the operation of applying a liquid and crimping. It is a figure for demonstrating the operation of applying a liquid and crimping. It is a figure for demonstrating the dentition state of a pressure tooth and a receiving tooth. It is a figure for demonstrating the dentition state of a pressure tooth and a receiving tooth. It is a figure for demonstrating the position of a sheet. It is a figure for demonstrating the position of a sheet. It is a figure for demonstrating the relationship between the number of sheets and the addition of a liquid. It is a figure which shows the block structure of a control system.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the attached drawings, the same or similar configurations are designated by the same reference numbers, and duplicate description is omitted.

As an embodiment of the present invention, a sheet processing device (finisher) incorporated in the image forming main body device is raised, but various modifications can be made without departing from the present invention, and the technical idea described in the claims All of the technical matters involved are the subject of this invention. The image forming main body apparatus is not limited, and a printing mechanism such as an electrostatic mechanism, an offset printing mechanism, an inkjet printing mechanism, and an ink ribbon transfer printing mechanism (thermal transfer ribbon printing, sublimation type ribbon printing, etc.) can be adopted.

In this embodiment, the sheet (recording medium) is a thin material in which moisture permeates and fibers are loosened. The structure and mechanism of the apparatus for performing hydroply-bonding in this example will be described in detail below. First, the liquid, which is more permeable than water for use in fastening, is a feature of this example. This will be described in detail.

The fastening method in this embodiment is performed by unraveling and then entwining the fibers constituting the sheet. Therefore, in order to unravel the fibers efficiently, it is necessary to quickly permeate the sheets to be fastened with water. Therefore, the liquid of this example is an aqueous solution having a lower surface tension than water.

The surface tension of the liquid is an index of the ease of penetration into the sheet. Liquids with low surface tension are more likely to penetrate the sheet than liquids with high surface tension.

As a method for adjusting the surface tension of a liquid, a method using a surfactant and a method using a solvent are known. When the surface tension is adjusted by using a surfactant, the surface tension can be adjusted by adding a small amount. On the other hand, when adjusting the surface tension using a solvent, it is necessary to add a larger amount than the surfactant. Further, since the solvent has high moisturizing property, it hinders evaporation of water after fastening the sheets. Therefore, it takes time to dry the sheet after fastening. For the above reasons, in this example, it is preferable to adjust the surface tension of the liquid by using a surfactant. Generally, the surface tension is a value measured by the Wilhelmy method as a static surface tension. The value of the static surface tension of water is "72.8 mN / m", and in this example, a liquid having a static surface tension of a lower value is used. More preferably, a liquid having a surface tension of "45.0 mN / m" or less is used. The static surface tension is the surface tension at the interface between a liquid and a gas when an equilibrium state is reached over time.

Further, in this embodiment, it is preferable that the value of the dynamic surface tension of the liquid is low. Dynamic surface tension is an index different from the above-mentioned static surface tension.

The static surface tension is the value of the surface tension in an equilibrium state after the material exhibiting surface activity is completely oriented at the interface between the liquid and the gas. On the other hand, the dynamic surface tension is a surface tension measured within the time until the material exhibiting surface activity is completely oriented. That is, the dynamic surface tension is an index of the temporal change of the surface tension. Alternatively, it can be said to be the value of surface tension after a predetermined time from the formation of the gas-liquid interface. The dynamic surface tension can be measured by the bubble pressure method, the drop volume method, or the like.

In this embodiment, it is desirable that the liquid permeates the sheet quickly in order to shorten the time required for fastening. Therefore, a liquid having a low surface tension in a short time is suitable for this embodiment. The measurement time of the dynamic surface tension is not particularly limited, but it is preferable that the result measured at 100 msec or less after the formation of the gas-liquid interface is low, and further, the result measured at 50 msec or less is low. That is, the liquid used in this example preferably changes to a value close to the static surface tension in a short time.

For example, the value of surface tension after 100 msec of water is "72.5 mN / m", and the value of surface tension after 50 msec is "72.3 mN / m". The liquid used in this example preferably has a surface tension lower than these values. Then, as described above, those that change to a value close to the static surface tension in a short time are preferable.

Further, in this embodiment, it is preferable that the surface tension of the liquid is equal to or less than the critical surface tension of the sheet to be fastened. The critical surface tension is a surface tension value at which the contact angle of the liquid in contact with the solid is 0 °. When the surface tension of the liquid is equal to or less than the critical surface tension of the solid in contact, the liquid tends to actively wet and spread with respect to the solid. Therefore, the liquid easily permeates the sheet.

The critical surface tension will be described. As a method for measuring the critical surface tension of a target individual, there is a general method proposed by Zisman. First, the contact angle θ with the target is measured for each of a plurality of saturated hydrocarbon liquids having different surface tensions (γ). Then, the relationship between the surface tension (γ) and the cosine of the contact angle (COSθ) is plotted. Based on the result of this plot, the value of the surface tension (γ) extrapolated so that the value of the cosine (COSθ) of the contact angle becomes 1, is the critical oil surface tension of the object.

However, in the recording medium centered on plain paper (general printing paper) as the object to be contacted with the liquid in this embodiment, the value of the critical surface tension is large, so the saturated hydrocarbon liquid as described above is used. It may not be possible to measure correctly with the existing measurement method. Therefore, in this example, the critical surface tension was measured using a solution in which water and ethanol were mixed at a plurality of mixing ratios.

As a result of the above measurement, the critical surface tension of plain paper was "45 mN / m", and the surface tension of the liquid used in this example is preferably less than this value. When there are a plurality of types of sheets to be bound, it is preferable that the surface tension of the liquid is less than the minimum value of the critical surface tension.

The organic solvent for adjusting the surface tension preferably used in this embodiment is not particularly limited as long as it can be dissolved in water, but 1,3-butyl glycol, 3-methyl-1,3-butyl glycol, triethylene glycol, etc. Polyethylene glycol, 1,5-pentanediol, 1,6-hexanediol, 1,2-hexanediol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2, Polyhydric alcohols such as 3-butanetriol and petriol; ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Polyhydric alcohol alkyl ethers; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1 , 3-Dimethylimidazolidinone, ε-caprolactam, γ-butyrolactone and other nitrogen-containing heterocyclic compounds; amides such as formamide, N-methylformamide, N, N-dimethylformamide; monoethanolamine, diethanolamine, triethylamine and the like. Aminates; sulfur-containing compounds such as dimethylsulfoxide, sulfolane, and thiodiethanol; propylene carbonate, ethylene carbonate, and the like. These water-soluble organic solvents can be used alone or in combination of two or more, and it is preferable that the amount of the solvent added is small in order to achieve a predetermined surface tension.

The surfactant for adjusting the surface tension, which is preferably used in this embodiment, is not particularly limited. The following are examples. The surfactant may be used alone or in combination of two. [Nonionic surfactant] Polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxy Ethylene / polyoxypropylene block copolymer, etc. Fatty acid diethanolamide, acetylene glycol ethylene oxide adduct, acetylene glycol-based surfactant, etc.

[Anionic Surfactant] Polyoxyethylene alkyl ether sulfate ester salt, polyoxyethylene alkyl ether sulfone salt, polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene alkyl phenyl ether sulfonate, etc. Alpha sulfo fatty acid ester salt, alkylbenzene sulphonate, alkylphenol sulphonate, alkylnaphthalin sulphonate, alkyltetraline sulphonate, dialkyl sulfosuccinate, etc.

[Cationic surfactant] Alkyltrimethylammonium salt, dialkyldimethylammonium chloride, etc.

[Amphitheater] Alkylcarboxybetaine, etc.

Among them, acetylene glycol-based surfactants, polyoxyethylene alkyl ethers, and the like are particularly preferably used because they can improve the ejection stability of the ink. As the acetylene glycol-based surfactant, (ethylene oxide adduct of 2,4,7,9-tetramethyl-5-decine-4,7-diol) is preferable.

The sheet used in the sheet processing apparatus of this embodiment is not particularly limited as long as it is paper generally used for printing. For example, so-called plain paper or PPC paper having a basis weight of 100 g / cm ² or less is preferably used. More preferably, any sheet of 90 g / cm ² or less can be preferably used. If it is larger than this, the sheet becomes thicker, so that the effect of this example is unlikely to be exhibited.

Subsequently, the structure and mechanism of the fastening portion for fastening the sheets using a liquid in the sheet processing apparatus using the present embodiment will be described. In the sheet processing apparatus of the present embodiment, a configuration capable of using a liquid according to the number of sheets to be fastened and a case of fastening without using the liquid of the present embodiment will be mentioned. Needless to say, the case where this embodiment is applied is the case where a liquid is used.

FIG. 1 is a diagram showing a configuration around a fastening portion for fastening the seat at the finisher. As shown in FIG. 1, a matching plate 59 is provided on the processing tray 58 on which the sheet is placed so as to move in the width direction intersecting from the sheet transport direction each time the sheet is carried out from a transport roller (not shown). .. The matching plate 59 is moved by the matching plate motor 59M of FIG. 19 and is provided so as to sandwich the sheet on both sides in the sheet width direction. As a result, the matching plates 59 move in the direction in which the distance between the matching plates 59 becomes narrower, and the sheets are aligned in the width direction. The processing tray 58 is provided with a paper ejection port (not shown) and a reference stopper 62 for abutting a sheet that is inclined downward and is transferred back by a return paddle or the like to the end thereof.

The binding unit 60 as the binding processing unit shown in FIG. 1 employs crimp binding in which sheets are crimped to each other with pressure teeth without using metal staples, and liquid is applied to the sheets during crimping. In addition, so-called water-bonding binding, which is binding, is possible. In the following, adding a liquid containing water may be referred to as "watering" in the description. Further, the binding unit 60 is located at the HP (home position) position in FIG. 1 during manual binding and hydration. Further, the binding unit 60 moves to each corresponding position in the case of front binding or rear binding and binding at two places.

[Structure of water pressure bonding]
From here, the binding unit 60 for applying a liquid to the binding position of the sheet and then crimping the sheet will be described with reference to the drawings in FIGS. 2 (a) and 2 (b) are perspective views of the (hydraulic pressure-bonded) binding unit 60, FIG. 2 (a) shows the back side, and FIG. 2 (b) shows the front side. 3 (a) and 3 (b) are side views of the binding unit 60, FIG. 3 (a) is a view from the rear side of the sheet processing apparatus, and FIG. 3 (b) is a view from the front side of the binding unit 60. ..

As shown in FIGS. 2 (a), 2 (b), 3 (a) and 3 (b), the binding unit 60 adds moisture to the sheet and raises and lowers one of the pressure teeth in FIG. 5 ( A) and FIG. 5 (b) include a water pressurizing portion 80 having a pressurizing tooth 82, a receiving tooth portion 126 having a receiving tooth 130, and a replacement fluid pump section (replenishment pump unit) 150 for adding water to a sheet. It is composed. One (upper) pressure tooth 82 constituting the pair of pressure teeth is surrounded by an elastic member 92 made of a rubber plate or the like and is provided on the pressure tooth support portion 84.

Further, the receiving tooth 130, which is the other (lower side) pressure tooth, is supported by the receiving tooth support portion 128 to form the receiving tooth portion 126. A sheet (bundle) placed on the processing tray 58 is sandwiched between the pressure teeth 82 and the receiving teeth 130. When performing the binding process, the pressure teeth 82 abut on the outermost sheet of the sheet bundle, and the receiving teeth 130 abut on the lowest sheet of the sheet bundle. Then, the sheet bundle is sandwiched between the pressurizing teeth 82 and the receiving teeth 130 to pressurize.

As shown in FIG. 3 (b), on the back surface side of the pressure tooth 82, a cylindrical shape constituting the liquid pool portion 88 of FIGS. 5 (a) and 5 (b) for holding the liquid to be applied to the sheet. Cylinder 90 is arranged. Above that, the cylinder guide 108 is located on the outer side in the circumferential direction of the pressure piston 104, which will be described later. It constitutes a liquid pressurizing member (hydrating member) applied by the pressurizing piston 104 and the cylinder 90.

Below, the receiving tooth 130 is supported by the receiving tooth support portion 128, and the receiving tooth support portion 128 also supports the lower surface of the seat. Further, below the receiving tooth support portion 128, a drainage dish 133 for receiving the residual liquid applied to the sheet is arranged.

Further, as can be seen from FIG. 3A, the replacement fluid pump unit 150, which serves as a replacement fluid pump section for replenishing the liquid pool portion 88, is bound adjacent to the rear side of the pressurizing tooth 82 and the receiving tooth 130. It is housed in the outer frame 120 of the unit 60. The replacement fluid pump unit 150 will also be described later, and includes a replacement fluid piston portion 154 that supplies fluid to the fluid pool portion 88, a replacement fluid head portion 156 that moves the replacement fluid piston portion 154, and a replacement fluid tank 174 that stores the replacement fluid. It is configured to include a replacement fluid tank portion 152. In FIG. 2A, the pump holding cover 192 covering the replacement fluid tank 174 is visible.

By the way, on the left and right sides of the cylinder 90 constituting the liquid pool portion 88 described above, the pressure tooth support portion 84 that supports the pressure tooth 82 and the elastic member (rubber plate) 92 and the presser plate 102 that raises and lowers the pressure tooth 82 A compression spring 96 is arranged between the and.

The pressing plate 102 is driven by a drive motor (binding motor 60M in FIG. 19) arranged in a space partitioned by the receiving tooth support portion 128 and the outer frame 120. The drive from the binding motor 60M to the pressing plate 102 is configured as follows. That is, as shown in FIGS. 2 (a) and 3 (a), the outer frame 120 on the rear side has an intermediate gear 138 on the motor output shaft gear 136 provided on the output shaft of the binding motor 60M as a drive motor. Are engaged.

The rotation of the intermediate gear 138 is transmitted to the cam gear 140 that rotates the moving cam 145 and the pinion gear 142 that moves the support rack 144 that moves to a position that does not support the bottom 175 of the replacement fluid tank. The pinion gear 142 includes a pinion gear 142a that receives transmission from the intermediate gear 138 and rotates together with the shaft, and a pinion gear 142b that transmits the transmission to the support rack 144 via a one-way clutch 147 with the rotating shaft. ing. As a result, whether or not to move the support rack 144 is selected according to the rotation direction of the drive motor 60, and the replacement fluid piston portion 154 is operated only when necessary. This point will be described later.

The moving cams 145 are arranged on both the front side and the rear side of the outer frame 120. The rotating arm 134 that moves by this is also attached to both sides so as to rotate by the arm fulcrum 146 attached to the outer frame 120. The rotating arm 134 is maintained in a state in which the rear end 143 of the arm is constantly in contact with the moving cam 145 by the return spring 149 stretched between the rotating arm 134 and the outer frame 120.

On the other hand, the upper movement pin 110 of the holding plate 102 of the holding plate 102 is inserted into the arm tip slit 148 on the tip side of the rotating arm 134. Therefore, when the moving cam 145 rotates, the tip side of the rotating arm 134 also moves up and down to move the pressing plate 102 up and down. On the front side (pressurized tooth 82 side) of the holding plate 102, the upper moving pin 110 and the lower moving pin 112 are inserted into the guide slit 124 of the outer frame 120.

The rear guide pin 116 is also inserted into the guide slit 124 of the outer frame 120 on the rear side (replenishment pump unit 150 side) of the presser plate 102. Since the upper movement pin 110 is also inserted into the arm tip slit 148 of the rotation arm 134, the holding plate 102 is moved up and down by the rotation arm 134. Therefore, the pressing plate 102 and the rotating arm 134 form a moving member.

The presser plate 102 moves up and down the water pressurizing unit 80, which will be described with reference to FIGS. 4 (a) to 7 (b). 4 (a) and 4 (b) are perspective views of the water-pressurizing portion 80 of the binding unit, FIG. 4 (a) is a side view, and FIG. 4 (b) is a slightly upward perspective view. 5 (a) and 5 (b) are cross-sectional explanatory views of the water pressurizing section 80, FIG. 5 (a) shows the front surface, and FIG. 5 (b) shows the side surface.

The water pressurizing portion 80 includes a pressing plate 102, a pressurizing tooth support portion 84, and a compression spring 96 interposed between them. An elastic member 92 made of a pressure tooth 82 and a rubber plate surrounding the pressure tooth 82 is provided on the side of the pressure tooth support portion 84 in contact with the sheet. On the back surface side of the pressure tooth 82 (the back surface side of the pressure tooth), a cylindrical cylinder 90 integrally formed with the pressure tooth support portion 84 and a guide bar 94 around which the above compression spring 96 is wound are cylinders. It is provided on both sides of the 90. The tip of the guide bar 94 is always inserted into the guide hole 114 of the holding plate 102.

As shown in FIGS. 5 (a) and 5 (b), the cylinder 90 is formed with a liquid pool portion 88 for holding a liquid to which about 1/3 in the height direction is applied to the sheet. There is. Further, the cylinder 90 is formed with a replenishment port 98 for receiving the liquid from the replacement fluid pump unit 150, which will be described later. In the figure shown, the pressure tooth 82 is also integrally formed, and the pressure tooth 82 is opened with a liquid supply hole (liquid supply pipe) 86 so that the liquid of the liquid pool portion 88 can be applied to the sheet.

Above the cylinder 90, there is a pressure piston 104 that is inserted into the cylinder 90 and pressurizes and moves the liquid in the liquid pool 88 so as to be applied from the liquid supply holes of the pressure teeth 82. ing. The pressure piston 104 is fixedly attached to the pressing plate 102 at its upper end. A piston packing 106 is wound around the circumference of the pressure piston 104 inserted into the cylinder 90. The piston packing 106 of FIGS. 5 (a) and 5 (b) is wound at one place, but if it is wound at two or more places, the pressurization when applying the liquid can be strengthened.

The presser plate 102 is provided with a cylinder guide 108 that moves to the outside of the cylinder 90 so that the pressurizing piston 104 can be inserted and the liquid can be pressed smoothly. Further, the holding plate 102 is provided with a guide hole 114, an upper moving pin 110 and a lower moving pin 112 inserted into the guide slit 124 of the outer frame 120, and a rear guide pin 116 fixedly provided. Of these, the upper moving pin 110 is longer outward than the other pins. This is so that it can be inserted into the arm tip slit 148 of the rotating arm 134 that rotates outside the outer frame 120.

The state in which the water pressurizing unit 80 configured as described above is compressed by the rotating arm 134 is shown in FIGS. 6 (a), 6 (b), 7 (a) and 7 (b). is there. FIG. 6A is a slightly upward perspective view, and FIG. 6B is a perspective view from below. The operation of the rotating arm 134 in the compressed state will be described later with reference to FIGS. 14 (a) to 14 (c) to 13 (a) to 13 (c).

In this compression state diagram, the presser plate 102 is in contact with the receiving tooth support portion 128 by the rotating arm 134, the compression spring 96 wound around the guide bar 94 is compressed, and the guide bar 94 is in the presser plate. The guide hole 114 of 102 protrudes. FIG. 6B is a view seen from the tooth support portion 128 side in response to this state, and the circumference of the pressure tooth 82 provided with the liquid supply hole (liquid supply pipe) 86 is elastic made of a rubber plate or the like. It is surrounded by a member 92. This is done by first pressing the pressure tooth support portion 84 against the sheet bundle, and then applying the liquid of the liquid pool portion 88 by the pressure piston 104, except for the range of crimping by the pressure tooth 82 at that time. This is to prevent the applied liquid from spreading.

7 (a) and 7 (b) are sectional views of the water pressurizing section 80, FIG. 7 (a) is a front sectional view in a direction crossing the cylinder 90 and the guide bar 94, and FIG. 7 (b) is a front sectional view. , FIG. 7 is a cross-sectional view across the cylinder 90 in a direction intersecting FIG. 7A. Then, in these figures, the liquid held in the liquid pool portion 88 in the cylinder 90 is the outermost sheet of the sheet bundle through the liquid supply hole (liquid supply pipe) 86 of the pressure tooth 82 by the pressure piston 104. Is given to and penetrates into the sheet bundle. Then, the sheet is pressed by the pressure piston 104 by receiving the force of the pressing plate 102 so as to receive the sheet bundle in which the liquid has permeated and engage with the teeth 130, and press the sheet.

The cylinder 90 is formed so that the inner diameter becomes narrower as the pressure piston 104 moves from above, and as described above, about 1/3 of the cylinder 90 in the height direction holds the liquid to be applied to the sheet. Part 88 is formed. From this position, the liquid pool portion 88 of the liquid pool portion 88 is pressurized and applied by the pressure piston 104. On the upper side, the liquid discharged from the replacement fluid pump unit 150 and replenished is received from the replenishment port 98 into the liquid reservoir 88, and the operation of the next pressurizing piston 104 is awaited. Therefore, the amount of liquid applied to the sheet at one time is approximately the amount held in the liquid reservoir 88.

[Fluid replacement pump]
Next, the replacement fluid pump unit 150, which is a replacement fluid pump unit that replenishes the liquid in the liquid reservoir 88 through the replenishment port 98, will be described with reference to FIGS. 8 to 10. As already described with reference to FIGS. 2A and 2B, the replacement fluid pump unit 150 is installed in the outer frame 120 of the binding unit 60 in the same manner as the pressure tooth support portion 84 and the receiving tooth portion 126. Has been done. Therefore, it is not necessary to crawl a pipe or the like for replenishing liquid from the outside of the binding unit 60, it is easy to handle, and the device becomes compact.

The replacement fluid pump unit 150 will be described with reference to the drawings. FIG. 8 is a cross-sectional explanatory view of the replacement fluid pump unit 150. FIG. 9 is an exploded perspective view of the replacement fluid piston portion 154, which is an important component of the replacement fluid pump unit 150, is an enlarged explanatory view of the replacement fluid piston portion 154, and FIG. 10 is an enlarged explanatory view of the water discharge state due to this. Is.

First, as shown in FIG. 8, the replacement fluid pump unit 150 has a replacement fluid head portion 156 that is pressed by the holding plate 102 and moves up and down, and a replacement fluid piston that temporarily holds the liquid and discharges the liquid to the replacement fluid head portion 156. A part 154 and a replenishment tank part 152 for storing a liquid to be replenished in the replenishment piston part 154 are included. The liquid discharged from the replacement fluid piston portion 154 by the ascending / descending movement of the replacement fluid head portion 156 is a liquid pool from the replacement fluid joint portion 158 whose protrusion port extends from the replacement fluid head portion 156 to the replacement port 98 of the water pressurization portion 80. The fluid is replenished in part 88.

In the replacement fluid tank portion 152, a moving plate 176 that moves as the liquid decreases each time the liquid is discharged to the replacement fluid joint portion 158 can be moved up and down by the replacement fluid piston portion 154 described with reference to FIGS. 9 to 10. It has become. Further, the bottom portion 175 of the replacement fluid tank portion 152 is provided with an air hole 178 that enables the movement of the moving plate 176.

Next, with reference to FIG. 9, the replacement fluid piston portion 154 that discharges the liquid to the replacement fluid head portion 156 will be described. The replacement fluid piston portion 154 is provided with a tank cap 172 screwed to the replacement fluid tank portion 152 and a replacement fluid cylinder 167 fixed to the tank cap 172 to temporarily hold the liquid in the replacement fluid tank portion 152. A sealing 171 for sealing is provided between the tank cap 172 and the replacement fluid tank 174 of the replacement fluid tank portion 152. In the binding unit 60, the tank cap 172 has a curved portion (FIGS. 4 (a) and 4 (b), 6 (a) and 6 (b) below the replenishment port 98 of the pressure tooth support portion 84. )) Is fitted and supported.

Further, the fluid replacement cylinder 167 is provided with an upper piston 162 that moves upward in the same manner as the fluid replacement head portion 156 moves up and down. An upper spring 169 is wound around the upper piston 162, and a pump valve 165 around which the upper spring 169 is similarly wound is arranged below. In the pump valve 165, a lower piston 163 in which a lower spring 170 is wound is located between the pump valve 165 and the lower part of the replacement cylinder 167. In the circumferential direction of the upper piston 162, a lower piston protrusion 164 that is crimped to the pump valve 165 and sealed is provided. The lower piston protrusion 164 is sealed by the lower spring 170.

At the lower end of the replacement fluid cylinder 167, a ball valve 166 for taking in the liquid in the replacement fluid tank 174 and sealing the replacement fluid cylinder 167 is provided. The ball valve 166 is located at the lower end of the replacement fluid cylinder 167 when the internal pressure inside the replacement fluid cylinder 167 increases, and moves slightly upward so as to take in the liquid in the replacement fluid tank 174 when the internal pressure decreases.

As shown in FIG. 10, when the replacement fluid head portion 156 is lowered by pressing the pressing plate 102, the upper piston 162 is also lowered in the replacement fluid pump unit 150 including the above. The upper spring 169, which is wound by this lowering, is also pushed and pushes the pump valve 165. As the pump valve 165 lowers, the ball valve 166 valve closes the lower end, so that the internal pressure of the replacement fluid cylinder 167 rises.

When the internal pressure of the fluid replacement cylinder 167 exceeds a certain value, the internal pressure causes the upper spring 169 wound around the fluid replacement cylinder 167 and the upper piston 162 to contract, so that a gap is provided between the pump valve 165 and the lower piston protrusion 164. Occurs. From this gap, the liquid in the replacement fluid cylinder 167 is discharged from the replacement fluid joint portion 158 of the fluid replacement head portion 156 to the fluid pool portion 88 through the pump valve 165, the upper part of the lower piston 163, and the upper piston 162 as shown by the arrows in FIG. To. When the amount of liquid in the replacement fluid tank 174 decreases, the moving plate 176 rises due to the decompression of the replacement fluid tank 174 so that the liquid level in the replacement fluid tank 174 is always constant.

In this way, each time the pressing plate 102 is pressed, the liquid in the replacement fluid tank 174 is replenished to the replenishment port 98 of the water pressurization section 80 through the replacement fluid joint section 158.

Hereinafter, the crimp binding operation of the sheet bundle placed on the processing tray 58 in the binding unit 60 will be described. When crimping with a pair of pressure teeth (pressurized teeth 82 and receiving teeth 130), the binding unit 60 is crimped without applying liquid (crimp binding without water), and liquid is applied to the crimped portion. The case of crimping after applying (hydraulic crimp binding) can be selectively executed. For example, it may be made executable according to a selection operation on the setting screen by the user.

[With water (water pressure) binding]
From FIGS. 11 (a) to 13 (c), an operation of applying a liquid to the crimping range before crimping by the pressure tooth 82 and then binding is described. 11 (a) to 11 (c) are state explanatory views from the front side of the binding unit 60, FIGS. 12 (a) to 12 (c) are state explanatory views from the rear side, and FIG. 13 ( a) to 13 (c) are cross-sectional explanatory views of water pressure-bonding binding. 11 (a), 12 (a), and 13 (a) show a state in which the pressure tooth support portion 84 (pressure tooth 82) is separated from the seat. 11 (b), 12 (b), and 13 (b) show a state in which the pressure tooth support portion 84 (pressure tooth 82) is pressed against the sheet. 11 (c), 12 (c), and 13 (c) show a state in which a liquid is applied to the sheet and crimped.

11 (a), 12 (a), and 13 (a) show the initial stage of receiving the sheet, which is placed on the processing tray 58, and the sheet is the pressure teeth 82 and the receiving teeth 130 of the binding unit 60. In between, it is placed on the receiving tooth support 128. In the drawings, the sheets are omitted in FIGS. 11 (a) to 11 (c) and 12 (a) to 12 (c), and the sheets are laminated in FIGS. 13 (a) to 13 (c). Indicates the state. When a specified number of sheets are loaded on the receiving tooth support portion 128 provided with the receiving teeth 130, the binding motor 60M is started to be driven. In this case, since the binding motor 60M rotates in the direction of water addition, it rotates in the direction opposite to the direction of crimping without water as shown in FIGS. 14 (a) to 14 (c), 15 and 16. Further, the number of sheets to be placed is more than 5, for example, 8 in the present embodiment.

That is, since the binding is performed with water in this example, the moving cam 145 drives the binding motor 60M in the counterclockwise direction on the front side and in the clockwise direction on the rear side (FIGS. 12 (a) to 12 (c)). ) In the clockwise drive motor). Since the moving cam 145 has a symmetrical shape with respect to the rotation position, the protruding side of the moving cam 145 also moves in the direction of pushing down the tip of the rotating arm 134. On the other hand, the pinion gear 142 (pinion gear 142b) engaged with the intermediate gear 138 starts moving in the direction of supporting the bottom portion 175 of the replacement fluid tank by the protrusion 141 of the support rack 144 by the action of the one-way clutch 147.

Here, the support rack 144 is interposed between the pinion gear 142 (pinion gear 142b) and the shaft by one-way rotation of the binding motor 60M (clockwise rotation in FIGS. 12A to 12C). The one-way clutch 147 engages and moves to a position where it supports the bottom 175 of the refill tank. By this movement, the bottom of the replacement fluid tank 175 is fixed, and when the replacement fluid head portion 156 is pressed by the pressing plate 102, the replacement fluid piston portion 154 operates, and the water in the replacement fluid tank 174 enters the fluid pool portion 88 via the replacement fluid joint portion 158. Fluid replacement can be supplied. As shown in FIGS. 13 (a) to 13 (c), a rack return spring between the support rack 144 and the outer frame 120 is disengaged and returned to the original position when the shaft is reversed. 139 is intervening.

Subsequently, in FIGS. 11 (b), 12 (b), and 13 (b), the pressing plate 102 is lowered, and the pressure tooth support portion 84 having the pressure teeth 82 is brought into close contact with the outermost sheet of the sheet bundle. When the pressing plate 102 is pressed in this state, the pressing tooth support portion 84 is pressed against the seat by the compression spring 96 interposed between the pressing plate 102 and the pressing tooth supporting portion 84. The pressure tooth support portion 84 is provided with an elastic member (rubber plate) 92 surrounding the pressure tooth 82 on the pressure tooth 82 side, and is pressed so as not to form a gap between the pressure tooth 82 and the seat surface. Here, a force of 70 kgf to 100 kgf is set to act on the seat. At this stage, the liquid is held in the liquid pool 88 by the operation of the replacement fluid piston portion 154, but the pressure piston 104 has not reached the position where the pressure is applied between the cylinder 90 and the cylinder 90. No water was added.

Next, in the states of FIGS. 11 (c), 12 (c), and 13 (c), the rotating arm 134 is further moved by the moving cam 145 while the pressure tooth support portion 84 is in close contact with the seat. The presser plate 102 is lowered. Then, the pressurizing piston 104 is inserted into the cylinder 90, and the liquid in the liquid pool portion 88 is hydrated from the pressurizing tooth 82 liquid supply hole (liquid supply pipe) 86 to the sheet. Even after the water addition is completed, the pressing plate 102 moves in the direction of crimping the sheet by the moving cam 145, whereby the pressure piston 104 receives the pressure teeth 82 and presses them toward the teeth 130 to crimp the sheet. The crimping at this time is weaker than the crimping force without water addition and can be crimped at 300 kgf to 400 kgf. Here, the voltage to the binding motor 60M is controlled so as to be 350 kgf to generate a pressing force.

As described above, the replacement fluid pump unit 150 sandwiches the replacement fluid head portion 156 and the replacement fluid tank bottom portion 175 with the support rack 144, and presses the replacement fluid head portion 156 to liquidate the liquid from the replacement fluid piston portion 154. The pool 88 is replenished. That is, as shown in FIGS. 13 (b) to 13 (c), the support rack 144 is located at the bottom 175 of the replacement fluid tank, and the replacement fluid pump unit 150 is fixed. As a result, the liquid is discharged from the fluid replacement piston portion 154, and the liquid is replenished to the fluid pool portion 88. Here, eight sheets are pressure-bonded to the processing tray 58 with water.

[Pressurized tooth and receiving tooth of hydropressurized part]
From here on, the pressurizing teeth 82 and the receiving teeth 130 of the water pressurizing section 80 will be described with reference to FIGS. 14 (a) to 14 (c), and these tooth engagement states and a liquid supply hole (liquid supply pipe) are shown in FIG. ) 86 positions will be described. First, FIG. 14A is a plan explanatory view of the pressure tooth, and as described above, a cylinder 90 for holding a liquid to be added to the sheet is provided on the back surface side of the pressurizing tooth 82 which is in contact with the sheet. It is provided. The cylinder 90 is formed in a cylindrical shape with a part cut off, and has a range in which the pressurizing piston 104 pressurizes and adds water (the range of the liquid pool 88) and a larger diameter than this, and the pressurizing piston 104 is inserted. It is configured to include a guide and a replacement fluid port 118 that receives liquid from the replacement fluid pump unit 150.

14 (b) is a cross-sectional explanatory view of the pressurized tooth 82 and the receiving tooth portion 126 of the alternate long and short dash line of FIG. 14 (a). As is clear from this figure, the pressure tooth support portion 84 is integrally formed with the pressure tooth 82, the cylinder 90 on the back surface side, and the guide bar 94. This ensures strength and ease of assembly. A drainage solution that temporarily holds the receiving tooth 130 (receiving tooth portion 126) that meshes with the pressurized tooth 82 and the remaining liquid (residual liquid) that has been hydrated under the pressure tooth support portion 84 at a position facing the pressure tooth support portion 84. A dish 133 is provided.

Then, a plurality of liquid supply holes (liquid supply pipes) 86 are provided in the inclined portion of the pressure tooth 82 so that the liquid in the liquid pool portion 88 can be added to the sheet. Further, the receiving tooth 130 is also provided with an outward communication hole 132 in the inclined portion for passing air when the seat is pressed by the pressure tooth support portion 84 and residual liquid when adding water. The capacity through which the communication hole 132 passes is formed larger than that of the liquid supply hole (liquid supply pipe) 86, and is formed so as to efficiently drain air and residual liquid.

FIG. 14C is a view of the pressure tooth support portion 84 viewed from the bottom surface on the pressure tooth 82 side, and an elastic member 92 made of a rubber material surrounding the pressure tooth 82 is attached to the pressure tooth support portion 84. It is attached. As a result, in the process of pressing the pressure tooth support portion 84 against the seat with the compression spring 96, the gap around the pressure tooth 82 is eliminated, and the applied liquid is reduced from spreading outside the pressure region to be crimped. ..

[Arrangement of liquid supply holes (liquid supply pipes) and communication holes]
Next, FIG. 15 shows the liquid supply holes (liquid supply pipes) 86 formed in the pressure teeth 82 of FIGS. 14 (a) to 14 (c) and the outside (drainage dish 133) formed in the receiving teeth 130. The communication hole 132 of the above will be described. FIG. 15 is enlarged for explaining the pressure tooth 82 and the receiving tooth 130, so that the pressure tooth 82 meshes with the receiving tooth 130 to form irregularities in the sheet bundle and entangles the fibers. It is composed of a peak portion 82a protruding from the receiving tooth 130, a recessed valley portion 82b, and an inclined portion 82c binding forming these. Further, the receiving tooth 130 is also configured to include the receiving peak portion 130a, the receiving valley portion 130b, and the receiving inclined portion 130c.

Then, the liquid from the liquid pool portion 88 in the cylinder 90 is discharged from the liquid supply hole (liquid supply pipe) 86 formed in the pressure tooth 82 by pressing the pressure piston 104. At that time, the liquid supply holes 86 are arranged so that the liquid is discharged from a plurality of inclined portions 82c as shown in the figure. With this arrangement, when the pressure teeth 82 and the receiving teeth 130 mesh with each other so as to form irregularities on the sheet as shown in the alternate long and short dash line in FIG. 15, the fibers of the sheet (paper In the case of cellulose fiber), it was confirmed that it could be melted (reciprocal arrow in the figure).

When the liquid is added to the position of the inclination where the fibers are most loosened, the liquid easily permeates, and the fibers are easily entangled by further pressurization thereafter. As a result, in the present embodiment, the liquid supply hole (liquid supply pipe) 86 for adding water is arranged in the inclined portion 82c of the pressure tooth 82. Further, the receiving inclined portion 130c of the receiving tooth 130 is also provided with a communication hole 132 having a larger capacity than the liquid supply hole (liquid supply pipe) 86 so that air and residual liquid can be easily removed.

[Pressurized tooth support and receiving tooth support]
Next, according to FIGS. 16 and 17 (a) to 17 (c), the relationship between the positions of the pressure tooth support portion 84 and the receiving tooth support portion 128 and the position of the sheet to be pinched and pressed between them is explain. FIG. 16 shows the sheet position when crimp binding is performed on the corners of the sheet on the front side of the processing tray 58 already described with reference to FIG. Here, when crimping the corners of the sheet, the sheet includes a pressure region in which the pressure teeth 82 and the receiving teeth 130 that engage with the pressure teeth 82 press the sheet. Position the seat. Further, the position of the seat is regulated so that the pressure tooth support portion 84 that supports the pressure tooth 82 and the bearing tooth support portion 128 that supports the receiving tooth 130 are L3 outside the corner portion of the seat. Tooth. At the same time, the pressurized tooth support portion 84 and the receiving tooth support portion 128 are not hydrated (due to hydration), which are in the center of gravity side of the L2-minute sheet from the position where the liquid hydrated from the pressurized tooth 82 permeates. Contact the position (where moisture has not penetrated).

17 (a) to 17 (c) show the liquid application region (hereinafter referred to as the application region) in which the liquid is applied to the sheet, and the pressurization of the sheet by the pressurizing teeth 82 and the receiving teeth 130 in this embodiment. It is a figure which shows the relationship with a region. By overlapping the applying region and the pressurized region, the crimping force of the sheet bundle can be improved as compared with the case where the liquid is not applied.

FIG. 17A is a cross-sectional view taken along the line Sc of FIG. According to this, the pressurizing tooth 82 and the receiving tooth 130 pressurize the imparting region L1.

In FIG. 17B, the imparting region L1 exceeds the range of the pressure region and enters the seat center of gravity side. Even in this case, the crimping force of the sheet bundle can be improved, but the fibers of the sheet remain in a loosened state due to water addition. Therefore, the sheet is easily torn at the position on the center of gravity side of the sheet. Further, if the sheet to which the liquid is applied is left in a state where it is not pressurized, the applied area of the sheet is wrinkled and the appearance is deteriorated.

In FIG. 17 (c), the imparting region L1 is larger than the pressure region and protrudes toward the sheet end portion (L5 portion). Even in this case, the crimping force of the sheet bundle can be improved, but the end side of the unpressurized sheet tends to fall apart. As shown in FIG. 17A, by arranging the applying region so as to be a part of the pressure region, it is possible to improve the fastening force of the sheet bundle without impairing the appearance of the sheet bundle.

In the above description, the front side of the processing tray 58 described with reference to FIG. 1 is shown. However, it goes without saying that the same effect can be obtained by processing the sheet in the same manner on the rear side of the processing tray 58.

Here, in the case of crimping without applying the liquid described in FIGS. 14 (a) to 14 (c) to 13 (a) to 13 (c), and in the case of crimping with liquid applied, water pressure crimp binding is performed. 18 (a) to 18 (d) will be described with respect to a predetermined number of sheets as a reference for cutting and the number of sheets to which crimping and liquid are applied.

FIG. 18A is a diagram illustrating a predetermined number of sheets relationship between the pressure teeth and the sheet, in which the upper side is the pressure teeth 82 and the lower side is the receiving teeth 130 as a pair of pressure teeth. As shown in this figure, the formation of unevenness on the sheet is composed of the height difference lh of the teeth that mesh with each other, in other words, the distance between the top of the mountain portion 82a and the bottom portion of the valley portion 82b. Normally, this height is formed to be about 0.4 mm to 0.6 mm, and the tooth engagement of the pressure tooth 82 receiving tooth 130 here is set to 0.5 mm.

On the other hand, the sheet used as ordinary copy paper is 68 g / square meter paper, and the thickness lp is about 0.1 mm. Therefore, 5 sheets are suitable for forming irregularities without applying liquid to this sheet. If the number exceeds 5, the crimping force between the sheets bound without applying the liquid becomes weak. Therefore, the predetermined number of sheets to be pressure-bonded by the water-bonding unit 60 without applying liquid is set to 5. When closing more than 5 sheets, liquid is applied to the sheet, and the paper fibers of the sheet are once unraveled and then pressure-bonded, so that water-bonding is performed. As another form, if the height difference between the teeth to be meshed is 0.6 mm, the predetermined number of teeth is 6, and if the height difference is 0.4 mm, the predetermined number of teeth is 4.

As described above, when binding a predetermined number of sheets or less, crimp binding is performed without applying a liquid, and when binding a sheet exceeding a predetermined number, a liquid is applied and pressure bonding is performed. In this way, water pressure bonding may be performed only when the pressure bonding force is reduced when the liquid is applied and bound.

[Explanation of control configuration]
From here, the control configuration of the image forming system 1 will be described with reference to the block diagram of FIG. The image forming system 1 shown in FIG. 19 includes an image forming apparatus and a sheet processing apparatus. The image forming apparatus includes an image forming control unit 200 that collectively controls the image forming apparatus, and the sheet processing apparatus includes a sheet processing control unit 205 (including a control CPU) that collectively controls the sheet processing apparatus.

In the image forming apparatus, the image forming control unit 200 is communicably connected to the paper feed control unit 202 and the input unit 203. The mode setting unit 201 has (1) printout mode, (2) job sorting mode, (3) binding processing mode, and (4) bookbinding (saddle stitching) from the control panel 26 provided on the input unit 203. The operation mode is set by selectively accepting each setting of the processing mode and (5) manual binding mode.

The sheet processing control unit 205 includes a control CPU and operates the sheet processing device according to the operation mode (sheet processing mode) set by the mode setting unit 201. The sheet processing control unit 205 is communicably connected to the ROM 207 that stores the operation program and the RAM 206 that stores the control data. Further, the sheet processing control unit 205 acquires detection information from various sensor input units 220.

[Various sensor inputs]
The various sensor input units 220 have an entrance sensor 38 that detects the transfer of the sheet on which the image is formed from the image forming apparatus, detects the front and rear ends of the sheet, and manages the main various motor drives. A seat sensor 39 for detecting a sheet jam or the like is located on the downstream side of the entrance sensor 38. Further, the processing tray 58 is provided with a processing tray empty sensor 58S for detecting whether or not a sheet is placed. Then, a loading tray position sensor 34S is provided to detect the paper surface of the loading tray 34 that accumulates the sheets discharged by the paper discharging roller while gradually descending. In addition to these sensors, sensors such as a punch unit, a position detection of the binding unit 60, and an operation detection of the saddle stitching unit may be provided.

[Output section of various motors, etc.]
The sheet processing control unit 205 is provided with a transport control unit 210 for transporting the sheet. The transfer control unit 210 includes a carry-in roller motor 41M for carrying in the sheet, a transfer roller motor 48M for transporting the sheet to the processing tray 58, and a paper ejection roller motor 52M for discharging the sheet from the processing tray 58. Control.

Further, a punch control unit 211 is provided at the rear end of the sheet carried in by the carry-in roller driven by the carry-in roller motor 41M to perform a punching process. The punch control unit 211 controls a punch motor 40M that punches holes at a designated position in the width direction of the sheet. Further, the processing tray control unit 212 controls the matching plate motor 59M that moves the matching plate 59 that aligns the sheets carried out to the processing tray 58 by sandwiching them from both sides in the sheet width direction.

The binding control unit 213 controls the binding motor 60M and the binding unit moving motor 60SM that moves the binding unit 60 to a designated position in the sheet width direction, and performs two-point binding and corner binding as shown in FIG. To do. The bound sheet bundle is discharged to the loading tray 34 by the bundle moving belt and the paper discharge roller driven by the paper discharge roller motor 52M. At that time, the tray elevating control unit 214 controls the integrated tray motor 34M by detecting the loading tray position sensor 34S so that the position of the upper surface of the sheet is always constant with respect to the paper ejection port.

The sheet processing control unit 205 may include blocks other than those shown in the figure. For example, a stacker control unit 215 for bookbinding (saddle stitching) processing, a saddle stitching control unit 216 for saddle stitching, a folding / discharging control unit 217, and the like may be provided with blocks corresponding to feasible post-processing.

In each of the binding processing mode and the manual binding mode, it is possible to execute a water binding mode in which water is added to the binding position and a water binding mode in which water is not added. Here, the sheet processing control unit 205 acquires the information on the number of bound sheets from the image formation control unit 200, and sets the water-bonded binding mode or the water-free binding mode according to the number of sheets.

The discriminating unit for determining whether the number of binding sheets is less than or equal to the predetermined number or exceeds the predetermined number is performed by any of the binding control unit 213, the sheet processing control unit (control CPU) 205, and the image formation control unit 200. You may. Further, the bundle of sheets sandwiched between the pressure teeth 82 and the receiving teeth 130 is measured by a known method and converted into the number of sheets, and the water binding mode and the waterless binding mode are set according to the number of sheet bundles. You may switch.

The invention is not limited to the above embodiments, and various modifications and modifications can be made without departing from the spirit and scope of the invention. Therefore, a claim is attached to make the scope of the invention public. Although the embodiments so far have shown suitable examples, those skilled in the art can realize various alternative examples, modified examples, modified examples, or improved examples from the contents disclosed in the present specification. These are included in the technical scope set forth in the appended claims.

1 Image formation system: 60 Binding unit: 82 Pressurized teeth: 86 Liquid supply hole: 90 Cylinder: 104 Pressurized piston: 200 Image formation control unit: 201 Mode setting unit: 205 Sheet processing control unit

Claims (8)

A means of applying liquid to the sheet and
Binding processing means for binding sheet bundles,
A sheet processing device for binding a bundle of sheets composed of a plurality of sheets.
The applying means applies the liquid to the outermost sheet of the sheet bundle, and the static surface tension of the liquid is smaller than the static surface tension of water.
The binding processing means includes a pair of pressure teeth, and the pressure teeth hold the sheet bundle and pressurize it.
In the sheet bundle, the liquid application region to which the liquid is applied and the pressure region to be pressed by the pressure teeth are provided to overlap each other.
A sheet processing device characterized by this. The sheet processing apparatus according to claim 1, wherein the dynamic surface tension of the liquid is smaller than the dynamic surface tension of water. The sheet processing apparatus according to claim 1 or 2, wherein the static surface tension of the liquid is equal to or less than the critical surface tension of the sheet to be bound. The pressurized tooth has a liquid supply hole and has a liquid supply hole.
The sheet processing apparatus according to any one of claims 1 to 3, wherein the applying means supplies the liquid from the liquid supply hole to the outermost sheet. The sheet processing apparatus according to any one of claims 1 to 4, wherein the liquid contains a surfactant. Further provided with an acquisition means for acquiring the number of sheets in the bundle of sheets,
Any one of claims 1 to 5, wherein when the number of sheets is less than or equal to a predetermined number, the binding process is performed by the binding processing means without applying the liquid by the applying means. The sheet processing apparatus according to. The sheet processing apparatus according to any one of claims 1 to 6, wherein the region for applying the liquid to the sheet is a part of a region with which the pressure teeth abut. The sheet processing apparatus according to any one of claims 1 to 7.
Including an image forming apparatus for forming an image on a sheet,
The sheet processing apparatus processes the sheet discharged from the image forming apparatus.
An image forming system characterized by this.