JP2017109257A - Drilling system, control method thereof, sheet processor and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling system capable of drilling a plurality of punch holes with high accuracy and high quality while conveying a sheet and a control method thereof.SOLUTION: A drilling system 100 is provided with a drilling device 1 having a punch member 21 which reciprocally moves in an axial direction by a drive motor 48, and drills a sheet S to be conveyed by a sheet conveyance mechanism 101. The punch member engages with punch holes to be drilled to integrally move with the sheet in a predetermined conveyance direction by force to be received from peripheral edges of the punch holes. A control part 80 determines a drilling operation starting position to scheduled drilling positions of the punch holes of the sheet in consideration of time until the punch member moves in the axial direction and a drilling blade starts to drill the punch holes after starting the drive motor, or a rotation amount of the drive motor, and controls timing for starting the drive motor.SELECTED DRAWING: Figure 16

Description

  The present invention relates to a punching system for automatically punching files or other punch holes in various sheet-like workpieces such as paper sheets, plastic sheets, metal sheets, and cloth sheets, and a control method thereof. The present invention further relates to a sheet processing apparatus and an image forming apparatus provided with such a punching system.

  Conventionally, for example, a binding hole for a file is automatically provided on a sheet such as a paper sheet that is mounted on an image forming apparatus such as a copying machine, a printing machine, a facsimile machine, a post-processing apparatus, or a bookbinding apparatus. A drilling device for drilling is used. In recent years, high-speed processing of sheets discharged from an image forming apparatus or the like has progressed, and in response to this, the punching device is also required to increase the speed and efficiency of the punching processing.

  Many perforating apparatuses perforate a sheet conveyed to a predetermined position by reciprocating a punch member in a perforating direction via a cam mechanism by a drive motor. At this time, if the conveyed sheet is decelerated or completely stopped and punched, the punching process cannot be speeded up. Therefore, a punching device that punches while conveying the punch and the die at the same speed as the sheet is known (see, for example, Patent Document 1).

  Further, when the punching operation is controlled by the rotation amount of the drive motor, the stop position of the punch member may vary because the motor rotation amount varies depending on the thickness and material of the sheet. If the punching operation is continuously executed in this state, the operation position of the punch member is gradually shifted, and problems such as sheet jam (paper jam) occur.

  Therefore, in order to solve such a problem, there has been proposed a punching device that controls the timing of operating the brake means to the drive motor of the punch member so as to vary according to the thickness of the sheet (for example, Patent Document) 2). Thus, the punch member is controlled to always stop at a predetermined position so that the rotation position of the drive motor and the operation position of the punch member do not shift when the punching operation is continued.

  Also, a conveyance roller that always conveys the paper downstream of the punching blade is provided so as to slide a predetermined amount with respect to the paper when the paper is restrained by the punching blade to absorb the tension acting on the paper from the conveyance roller. A paper punching device that does not cause damage due to the bending of the paper is known (see, for example, Patent Document 3). This paper punching device further reduces damage to the paper by the punching blade by setting the product of the time during which the paper is restrained by the punching blade and the transport speed by the transport roller to be a predetermined value. .

JP 2008-173734 A JP 2012-139815 A Japanese Patent Laid-Open No. 7-186098

  Generally, when punching a sheet discharged from an image forming apparatus or the like, a plurality of punch holes are punched as a file binding hole in one sheet. In order to cope with the high-speed processing of the image forming apparatus, it is necessary to punch a plurality of punch holes in one sheet at high speed with high accuracy and high quality.

  However, in the paper punching device of Patent Document 1, the punch unit and the die unit are moved to a predetermined position in the sheet width direction after detecting the leading edge and the side edge of the sheet, and after detecting the trailing edge of the sheet, While moving to the downstream side in the sheet conveying direction at the same speed, the punch is moved up and down to make a hole at the rear end of the sheet. Therefore, in order to make a plurality of punch holes in one sheet, the same number of punch units and die units as the number of punch holes and a crank for reciprocating them at the same speed as the sheet conveying speed A mechanism is needed. For this reason, the entire apparatus becomes large, the control of each punch unit and the crank mechanism becomes complicated, and there is a possibility that high-accuracy and high-quality drilling and its speed cannot be accommodated.

  In the punching device of Patent Document 2, in order to punch a plurality of punch holes in a sheet, a plurality of punch members are alternately operated with a time difference by one drive motor. The paper punching device disclosed in Patent Document 3 also drives a plurality of punching blades arranged in a straight line at a predetermined interval by individual driving means and punches along the rear end of the paper. In either case, as in the apparatus of Patent Document 1, it is only possible to punch punch holes equal to or less than the number of punch members to be equipped at preset positions. These apparatuses are also difficult to cope with downsizing, high-speed processing, high-precision and high-quality drilling.

  Therefore, the present invention has been made in view of the above-described problems of the prior art, and the purpose thereof is to continuously punch a plurality of punch holes with high quality and high accuracy while conveying a sheet. An object of the present invention is to provide a drilling system capable of handling high-speed processing and a control method thereof.

In order to achieve the above object, the drilling system of the present invention provides
A punch member having a perforated blade at one end in the axial direction and reciprocating in the axial direction;
A drive motor that reciprocates the punch member in the axial direction so that a punch hole is punched by a punching blade in a sheet transported in a predetermined transport direction;
A control unit for controlling the drive motor,
The punch member is movable together with the sheet in a predetermined conveying direction by engagement with a punch hole being punched,
The control unit controls the timing of starting the drive motor based on the sheet conveyance amount linked to the displacement amount of the punch member until the punching blade starts to punch the punch hole after starting the drive motor. Features.

  In this way, by directly linking to the displacement amount of the punch member that punches the punch hole, the start timing of the drive motor is controlled based on the sheet conveyance amount, so that the desired punch hole punching position on the sheet is always maintained. In addition, it is possible to drill the punch hole by matching the timing of the drilling start more accurately. Thereby, a plurality of punch holes can be continuously drilled in the sheet with high accuracy.

  In an embodiment, the conveyance amount of the sheet is a length in a predetermined conveyance direction starting from the leading edge of the sheet, whereby the timing for starting the drive motor can be easily and accurately derived.

  In another embodiment, a sensor for detecting the leading edge of the sheet is further provided, and the control unit determines the timing for starting the drive motor with the detection of the leading edge of the sheet output from the sensor as a starting point. As a result, it is possible to easily and accurately derive the timing for starting the drive motor in order to punch holes in the entire length of the sheet along the predetermined conveyance direction.

  In a certain embodiment, a control part determines the displacement amount of a punch member with the rotation time after starting of a drive motor. Since the time until the punch member starts punching a punch hole after the drive motor is started can be known in advance from the test result of the punch system, the start timing of the drive motor can be accurately determined.

  In another embodiment, a control part determines the amount of displacement of a punch member with the amount of rotations after starting of a drive motor. Similarly, since the rotation amount until the punch member starts punching a punch hole after the drive motor is started can be known in advance from the test results of the punch system, the start timing of the drive motor can be accurately determined. it can.

  In yet another embodiment, the punch member reciprocates in the axial direction while rotating about its axis to punch holes in the sheet, and the control unit rotates the punch member after the drive motor is activated. To determine the amount of displacement of the punch member. Since the start timing of the drive motor is directly determined from the rotational position of the punch member that is disengaged from the engagement with the punch hole, it can be controlled more accurately.

  Further, in an embodiment, in order to convey the sheet in a predetermined conveyance direction, the sheet further includes a conveyance roller pair disposed on the upstream side of the punch member and a conveyance roller pair disposed on the downstream side, The nip pressure of the transport roller pair is larger than the nip pressure of the downstream transport roller pair, and the sheet transport speed of the downstream transport roller pair is faster than the sheet transport speed of the upstream transport roller pair. As a result, while the sheet is sandwiched between both the upstream and downstream conveying roller pairs, a slip is generated between the roller surface of the downstream conveying roller pair and the sheet, so that the sheet is upstream and downstream. Because it is transported at a constant speed determined by the upstream transport roller pair without causing slack between the transport roller pairs, the drive motor start timing is always accurately controlled based on the sheet transport amount. can do.

  In another embodiment, the friction coefficient of the roller surface of the downstream conveyance roller pair is smaller than the friction coefficient of the roller surface of the upstream conveyance roller pair, so that the distance between the roller surface of the downstream conveyance roller pair and the sheet is low. It is possible to make slip easily.

  In another embodiment, in order to convey the sheet in a predetermined conveyance direction, a conveyance roller pair disposed upstream and / or downstream of the punch member, and a conveyance roller pair that is pulse-controlled by the control unit. A drive driving motor for driving, and in order to make a plurality of punch holes in the sheet, a deviation between a desired drilling planned position and an actual punching position of the plurality of punch holes is 1 / The control unit controls the conveyance drive motor so that it is within the range of the sheet conveyance amount for two pulses. As a result, a plurality of punch holes can be drilled within a range of a minimum deviation from a desired planned drilling position, and a drilling system with high hole position accuracy can be obtained.

The punching system control method according to the present invention has a punching blade at one end in the axial direction, punches a punch member that can reciprocate in the axial direction, and a punched hole in a sheet transported in a predetermined transporting direction. A punching system that includes a drive motor that reciprocates the punch member in the axial direction, and the punch member is movable together with the sheet in a predetermined conveyance direction by engagement with the punch hole being punched,
The timing for starting the drive motor is controlled based on the sheet conveyance amount linked to the displacement amount of the punch member until the punching blade starts to punch the punch hole after starting the drive motor.

  In this way, by directly linking to the displacement amount of the punch member that punches the punch hole, the start timing of the drive motor is controlled based on the sheet conveyance amount, so that the desired punch hole punching position on the sheet is always maintained. In addition, it is possible to drill the punch hole by matching the timing of the drilling start more accurately. Thereby, it is possible to continuously punch a plurality of punch holes in the sheet with high accuracy.

  In an embodiment, the conveyance amount of the sheet is a length in a predetermined conveyance direction starting from the leading edge of the sheet, whereby the timing for starting the drive motor can be easily and accurately derived.

  In another embodiment, before starting the driving motor, the leading edge of the conveyed sheet is detected, and the timing for starting the driving motor is determined using the detection of the leading edge of the sheet as a starting point. As a result, it is possible to easily and accurately derive the timing for starting the drive motor in order to punch holes in the entire length of the sheet along the predetermined conveyance direction.

  In one embodiment, the amount of displacement of the punch member is determined by the rotation time after activation of the drive motor. Since the time until the punch member starts punching a punch hole after the drive motor is started can be known in advance from the test result of the punch system, the start timing of the drive motor can be accurately determined.

  In another embodiment, the amount of displacement of the punch member is determined by the amount of rotation after activation of the drive motor. Similarly, since the rotation amount until the punch member starts punching a punch hole after the drive motor is started can be known in advance from the test results of the punch system, the start timing of the drive motor can be accurately determined. it can.

  In yet another embodiment, the punch member reciprocates in the axial direction while rotating about its axis to punch holes in the sheet, and the punch member displacement amount is determined by the punch member after activation of the drive motor. Determined by the rotational position. Since the start timing of the drive motor is directly determined from the rotational position of the punch member that is disengaged from the engagement with the punch hole, it can be controlled more accurately.

  Further, in an embodiment, the punching system is pulse-controlled by a control unit and a pair of transport rollers disposed on the upstream side and / or the downstream side of the punch member to transport the sheet in a predetermined transport direction. A conveyance drive motor for driving the pair of conveyance rollers, and in order to punch a plurality of punch holes in the sheet, a deviation between a desired drilling scheduled position of the plurality of punch holes and an actual punching position is determined by the conveyance drive motor. The rotation of the conveyance drive motor is controlled so as to be within the range of the sheet conveyance amount for 1/2 pulse. Thereby, when drilling a plurality of punch holes, it is possible to suppress deviation from a desired planned drilling position within a minimum range, and it is possible to improve the hole position accuracy of the drilling system.

  According to another aspect of the present invention, there is provided a sheet processing apparatus provided with the above-described punching system of the present invention, thereby enabling a plurality of punch holes to be punched with high accuracy and high quality while conveying the sheet. .

  Further, according to another aspect of the present invention, the punching system of the present invention described above or the sheet processing apparatus of the present invention described above is provided, whereby a plurality of punch holes are raised while conveying the sheet after image formation. Provided is an image forming apparatus that can be punched with high accuracy and high quality.

1 is a plan view showing an embodiment of a drilling system according to the present invention. FIG. 2 is a side view of the drilling system of FIG. 1. The front view of a punching apparatus. The side view of a punching apparatus. The top view of a punching device. The longitudinal cross-sectional view which shows the perforation part of a perforation apparatus. The perspective view which shows a sheet | seat press part and a perforation part. The block diagram which shows the control structure of the drilling system of FIG. FIGS. 5A and 5B are a partial cross-sectional side view and a top view of the punch member showing an operation state of the punching system in which the punch member is at the top dead center position in the sheet punching process. (A) Drawing and (b) figure are the fragmentary sectional side views and the top view of a punch member which show the operation state of a punching system in which the cutting edge of a punch member fell to the upper end position of a sheet passage. (A) Drawing and (b) figure are the fragmentary sectional side views and the top view of a punch member which show the operation state of the punching system in which the blade edge of the punch member fell to the sheet upper surface position. FIGS. 5A and 5B are a partial cross-sectional side view and a top view of the punch member showing an operation state of the punching system in which the punch member has reached the bottom dead center position. FIGS. 4A and 4B are a partial cross-sectional side view and a top view of the punch member showing an operation state of the punching system in which the cutting edge of the punch member is raised to the upper surface position of the sheet in the process of returning from the punch hole. FIGS. 5A and 5B are a partial cross-sectional side view and a top view of the punch member showing an operating state of the punching system in which the cutting edge of the punch member is raised to the upper end position of the sheet path. FIGS. 5A and 5B are a partial cross-sectional side view and a top view of the punch member showing an operation state of the punching system in which the punch member returns to the top dead center position. The timing chart explaining control of a drilling system. (A)-(c) is a figure explaining the setting of the starting timing of the drive motor using the 1st sheet sensor for punching the first punch hole in a sheet. (A)-(c) is a figure explaining another setting of starting timing of a drive motor using the 1st sheet sensor for punching the first punch hole in a sheet. (A)-(c) is a figure explaining the setting of the starting timing of the drive motor using the 2nd sheet sensor for punching the first punch hole in a sheet | seat. (A)-(c) is a figure explaining the setting of the starting timing of the drive motor using the 1st sheet sensor for punching the last punch hole in a sheet. The figure explaining the control which adjusts the several punch hole drilling position on a sheet | seat.

DESCRIPTION OF EMBODIMENTS Hereinafter, a drilling system of the present invention will be described in detail based on an embodiment thereof with reference to the accompanying drawings.
The punching system of the present embodiment is incorporated in a main body device such as an image forming apparatus or a post-processing apparatus, for example, and is used for punching holes while conveying a sheet such as a paper sheet carried from the image forming apparatus. To do. In particular, the punching system is suitable for punching a plurality of punch holes in one sheet, such as a file binding hole.

  1 and 2 show the overall configuration of a drilling system 100 according to a preferred embodiment of the present invention. The punching system 100 includes a punching device 1, a frame 2 to which the punching device is attached, and a sheet transport mechanism 101 that transports the sheet S. The sheet conveying mechanism 101 extends from the upstream side to the downstream side of the punching device 1 along the sheet conveying direction A, and has an upper guide plate 102 and a lower guide plate 103 that are arranged to face each other. Between the upper guide plate and the lower guide plate, a guide path 104 for the sheet S having a certain slight gap is defined.

  On the upper and lower guide plates 102, 103, a pair of upper and lower carry rollers 105, 106 are arranged symmetrically with respect to the sheet conveyance direction A on the upstream side immediately in the sheet conveyance direction A of the punching device 1. Yes. Further, four pairs of upper and lower pair of carry-out rollers 107 and 108 are arranged symmetrically on the downstream side of the punching device 1 in the sheet conveying direction A. In particular, the pair of carry-out rollers 107 a and 108 a disposed at the end on the side of the punching device 1 are disposed at corresponding positions in the left-right direction on the downstream side of the punching position of the punching device 1.

  Each of the carry-in roller pairs is rotatably supported by carry-in roller shafts 109 and 110 that traverse the upper and lower guide plates 102 and 103 in the left-right direction. Similarly, each of the carry-out roller pairs is rotatably supported by carry-out roller shafts 111 and 112 that traverse the upper and lower guide plates 102 and 103 in the left-right direction.

  The upper carry-in roller shaft 109 and the carry-out roller shaft 111 are urged at a predetermined pressure toward the lower carry-in roller shaft 110 and the carry-out roller shaft 112 by coil springs 113 and 114, respectively. Accordingly, the outer peripheral surfaces of the upper carry-in roller 105 and the carry-out roller 107 press the corresponding outer peripheral surfaces of the lower carry-in roller 106 and the carry-out roller 108 with the predetermined pressure, respectively. By this pressing force, each of the carry-in and carry-out rollers sandwiches the sheet S in the guide path 104 from above and below through windows opened on the upper and lower guide plates 102 and 103, respectively. It conveys in the conveyance direction A by rotation.

  The lower carry-in roller shaft 110 and the carry-out roller shaft 112 are connected to each other at their opposite ends 110 a and 112 a by a belt transmission mechanism including pulleys 115 and 116 and a belt 117. Similarly, the opposite end 110b of the carry-in roller shaft 110 is connected to an output shaft (not shown) of the drive motor 120 by a belt transmission mechanism including a pulley 118 and a belt 119. Accordingly, when the drive motor is rotated, the lower carry-in roller shaft 110 and the carry-out roller shaft 112 are rotationally driven in the sheet conveyance direction, and the upper carry-in roller pressed against the lower carry-in roller 106 and the carry-out roller 108. Similarly, 105 and the carry-out roller 107 rotate in the sheet conveyance direction.

  In the present embodiment, the outer diameter of the driving-side carry-out roller 108 is set slightly larger than the outer diameter of the driving-side carry-in roller 106. As described above, since the carry-out roller 108 and the carry-in roller 106 are rotationally driven by the common drive motor 120 via the belt transmission mechanism, the sheet conveyance speed of the carry-out roller 108 is higher than the sheet conveyance speed of the carry-in roller 106. The difference in roller outer diameter is faster.

  Furthermore, the biasing force of the coil spring 114 on the carry-out side is set to be weaker than the biasing force of the coil spring 113 on the carry-in side. Thereby, the pressing force acting between the carry-out rollers 107 and 108, that is, the nip pressure for nipping the sheet between the rollers is set somewhat lower than the nip pressure acting between the carry-in rollers 105 and 106. Therefore, since the sheet conveying force of the unloading roller pair 107 and 108 is weaker than that of the loading roller pair 105 and 106, when the sheet is nipped and conveyed simultaneously by the loading roller pair and the unloading roller pair, the sheet and the roller surface A slip occurs between the two. Accordingly, the sheet is conveyed at the sheet conveyance speed of the carry-out roller 108.

  In another embodiment, the roller surface of the carry-in roller 106 is formed of a roller material excellent in frictional force such as a rubber material that is often used for a sheet conveyance roller, whereas the roller surface of the carry-out roller 108 is formed. It is made of a material with a smaller frictional force. Examples of the roller material having a small frictional force include a plastic resin material having a relatively low friction coefficient. Thus, by reducing the friction coefficient of the roller surface, the nip pressure of the carry-out roller pair 107 and 108 can be similarly set lower than that of the carry-in roller pair 105 and 106.

  The punching device 1 is fixed to the frame 2 using an attachment unit 3. The attachment unit 3 has a lower support member 4 fixed to the frame 2 and an upper movable attachment member 5 movable with respect to the support member. The movable attachment member 5 can move linearly in both directions along the sheet conveying direction within a predetermined movement range defined by guide rod means (not shown) provided on the support member 4.

  3 to 6 show the entire configuration of the perforation apparatus 1. The punching device 1 includes a punching unit 11, a drive unit 12, and a frame structure 13. The frame structure 13 includes a lower frame 14 for guiding a sheet to be punched and for mounting the punching device 1 to the mounting unit 3, and an upper frame 15 for assembling the punching unit 11 and the drive unit 12. The

  A pin 121 protrudes from the frame 2 immediately upstream in the sheet conveying direction of the punching device 1. A tension coil spring 122 is interposed between the punching device 1 and the frame 2 with each end engaged with the upper frame 15 and the pin 121. The punching device 1 is always urged upstream by the tension coil spring 122 toward the home position at the upstream end of the moving range.

  As shown in FIGS. 3 and 4, the lower frame 14 is formed of a substantially rectangular flat plate member, and the upper surface thereof is a horizontal and flat sheet support surface 14a for supporting the sheet S that is a work piece to be punched. Is defined. The upper frame 15 has a lower plate 16 disposed so as to face the seat support surface 14a with a certain slight gap. A slight gap between the sheet support surface 14a and the lower plate 16 defines a sheet path 17 for allowing the sheet S to pass through the punching position. The lower frame 14 and the lower plate 16 of the upper frame 15 are integrally coupled with the spacer plate at the end opposite to the seat passage 17.

  The sheet support surface 14 a is disposed so as to be flush with the upper surface of the lower guide plate 103 of the sheet conveying mechanism 101. The sheet path 17 is provided at substantially the same height as the guide path 104 of the sheet conveying mechanism 101. Thereby, the sheet conveyed through the guide path 104 can pass smoothly on the sheet support surface 14a of the punching device 1.

  As shown in FIGS. 3 and 5, the upper frame 15 is provided with the perforated portion 11 on the seat passage 17 side and the drive portion 12 on the opposite side. The upper frame 15 is bent vertically upward from the end of the lower plate 16 opposite to the drive portion 12 and vertically upward from the upstream end of the lower plate 16. It further includes a side plate 19 and an upper plate 20 that is bent inwardly in parallel with the lower plate 16 at the upper end of the side plate 19, that is, horizontally to form a U-shape as a whole.

  As shown in FIG. 6, the perforated portion 11 includes a circular rod-shaped punch member 21 that extends in the vertical direction and has a substantially constant diameter over the entire length. The punch member 21 has a cylindrical punching blade 22 formed at the lower end thereof. The perforating blade 22 is formed so as to cut out the cylindrical peripheral edge of the punch member 21 in a V shape when viewed from the side, that is, to define a V-shaped notch at a certain facing side surface position of the cylindrical peripheral edge. Is formed. The punch member 21 has two diametrical through-holes 23 and 24 formed in the upper and lower portions, and a relatively narrow circumferential groove 25 is provided around the entire circumference in the vicinity of the center in the axial direction. Yes.

  Circular through holes 26 and 27 are formed in the lower plate 16 and the upper plate 20 of the upper frame 15 at positions corresponding to the vertical direction, respectively. An upper end portion of the punch member 21 is inserted into the upper through hole 27 and a lower end portion thereof is inserted into the lower through hole 26 so as to be rotatable and slidable in the axial direction. A circular die hole 28 for punching the sheet S by the punching blade 22 is provided in the lower frame 14 at a position corresponding to the through hole 26 of the lower plate 16 in the vertical direction.

  The punch member 21 is externally provided with a cam member 31 formed of a cylindrical cam concentrically therewith. The cam member 31 can be composed of a substantially cylindrical upper cam half 31a and a lower cam half 31b. The upper cam half body 31a and the lower cam half body 31b are assembled so as to be able to rotate integrally in the circumferential direction by fitting each other vertically.

  An upper cam surface 32a is formed on the lower surface of the upper cam half 31a so as to be continuous over the entire circumference along the outer peripheral edge thereof. A lower cam surface 32b is formed on the upper surface of the lower cam half 31b so as to be continuous over the entire circumference along the outer peripheral edge thereof. By integrating the two cam halves 31a and 31b as described above, an endless cam groove 33 is formed on the outer peripheral surface of the cam member 31 in the circumferential direction.

  On the side plate 18, cam pins 34 project horizontally toward the outer peripheral surface of the cam member 31. The cam pin 34 is disposed so as to fit into the cam groove 33 and engage with the upper cam surface 32a and / or the lower cam surface 32b.

  On the lower surface of the cam member 31 (lower cam half 31b), a narrow groove 35 having a predetermined depth extending in the diameter direction from the periphery of the shaft hole through which the punch member 21 is inserted is formed. On the upper surface of the cam member 31 (upper cam half 31a), a step 36 having a predetermined width and depth is provided along the periphery of the shaft hole through which the punch member is inserted.

  The narrow groove 35 on the lower surface of the cam member 31 is fitted with both end portions of the connecting pin 37 inserted through the lower through hole 24 of the punch member 21 and projecting from both ends of the through hole. For example, a rubber ring 38 is fitted into the step 36 on the upper surface of the cam member 31, and an E ring 39 is fitted into the circumferential groove 25 of the punch member 21 immediately above. Accordingly, the cam member 31 is integrally attached to the punch member 21 in the axial direction and the circumferential direction.

  A sensor flag member 41 is integrally fixed to the upper surface of the cam member 31 as a position detecting member for a position sensor described later. The sensor flag member 41 is formed of a fan-shaped light shielding plate having a fixed width and extending horizontally outward in the radial direction around the axis of the punch member 21.

  A driven gear 42 is concentrically mounted on the punch member 21 at an upper end portion protruding upward from the through hole 27 of the upper plate 20. As will be described later, the driven gear 42 is a worm wheel or a helical gear that meshes with a worm or screw gear on the driving side. The driven gear 42 is formed with a narrow groove 43 extending in the diametrical direction from the periphery of the shaft hole through which the punch member 21 is inserted.

  The narrow groove 35 on the lower surface of the cam member 31 is fitted with both end portions of the connecting pin 44 inserted through the upper through hole 23 of the punch member 21 and projecting from both ends of the through hole. The both end portions of the connecting pin 44 are disposed in the narrow groove 35 so as not to move in the rotational direction of the cam member 31 and to be slidable in the axial direction of the cam member. Further, the driven gear 42 is supported with its lower surface in sliding contact with the upper surface of the upper plate 19. Thus, the driven gear 42 is held so as to be integrally rotatable in the circumferential direction with respect to the punch member 21 and relatively movable in the axial direction.

  As shown in FIG. 4, the upper frame 15 is provided with a sheet pressing portion 70 for pressing the sheet S in the sheet passage 17 against the sheet support surface 14 a on the upstream side in the sheet conveying direction of the punching portion 11. . The sheet pressing portion 70 includes a leaf spring member 71 obtained by bending a thin metal plate made of a spring material such as spring steel into a V shape. The leaf spring member 71 has the bent portion 74 in the seat with the upper surface of the upper spring plate portion 72 facing the lower surface of the cam member 31 and the lower surface of the lower spring plate portion 73 facing the seat support surface 14a. It arrange | positions toward the upstream of a conveyance direction.

  The sheet pressing portion 70 further includes a swing arm 75 for supporting the leaf spring member 71 and a fixture 76 fixed to the side plate 19 of the upper frame 15. The swing arm 75 protrudes laterally from both side edges of the upper spring plate portion 72, and a plate portion extending beyond the bent portion toward the bent portion 74 along the both side edges is bent at a right angle upward. And is pivotally supported by the fixture at the end on the bent portion side so as to swing up and down. Accordingly, the leaf spring member 71 is supported on the side plate 19 of the upper frame 15 so as to be swingable up and down between the cam member 31 and the seat support surface 14a.

  As shown in FIG. 7, the upper spring plate portion 72 has a distal end bent slightly downward to form a cam receiving portion 77 for contacting the lower surface of the cam member 31. The lower spring plate portion 73 is bent slightly upward from the vicinity of the middle portion thereof to form a sheet presser 78 for pressing the sheet S in the sheet passage 17 against the sheet support surface 14a.

  The sheet presser 78 is formed in a Y shape whose front end opens toward the downstream side, and the punch member 21 can penetrate through the opening 78a without contacting the periphery of the opening up and down. Yes. The sheet presser 78 abuts on a sheet portion formed by or formed around the punch hole by the punch member 21. The front end of the sheet presser 78 is bent slightly upward so as to come into contact with the upper surface of the sheet without being caught.

  When the cam receiving portion 77 is pushed down to the lower surface of the cam member 31 and the distance between the upper spring plate portion 72 and the lower spring plate portion 73 is reduced, the plate spring member 71 exerts a biasing force, and the sheet presser 78 is The sheet S is pressed against the sheet support surface 14a. The pressing force applied from the sheet presser 78 to the upper surface of the sheet S increases or decreases depending on the displacement amount of the leaf spring member 71 caused by the cam receiving portion 77 being pushed down to the lower surface of the cam member 31, that is, the axial displacement amount of the lower surface of the cam member. To do.

  The drive unit 12 includes a drive motor 48 for rotating the punch member 21. The upper frame 15 has a side plate 46 disposed opposite to the side plate 18 on the opposite side of the perforated portion 11. The drive motor 48 is mounted horizontally on the side plate 46 with its output shaft 49 protruding horizontally toward the perforated portion 11.

  A driving gear 50 is attached to the tip of the output shaft 49. The driving gear 50 meshes with an intermediate gear 52 that is rotatably mounted on a horizontal rotating rod 51 that is rotatably supported between the side plate 20 and the side plate 18. A worm 53 is formed on the rotating rod 51 and meshes with the driven gear 42. Thereby, the rotation of the drive motor 48 can be transmitted to the punch member 21, and the punch member can be decelerated and rotated.

  In order to detect the rotation amount of the drive motor 48, for example, an optical transmission type encoder 55 is provided on the side opposite to the perforated portion 11. Thereby, the rotation of the drive motor 48 can be controlled with higher accuracy in relation to the position of the sheet S with respect to the punching device 1, for example.

  In the upper frame 15, a position sensor 60 for detecting the rotational position of the punch member 21 is attached to the extension portion 47 of the side plate 46 on the side opposite to the rotating rod 51. The position sensor 60 is a transmissive photosensor, and includes a rectangular box-shaped light projecting unit 62 and a light receiving unit 63 that project toward the punch member 21. The light projecting unit 62 and the light receiving unit 63 are arranged so as to face each other with a predetermined gap therebetween so that the sensor flag member 41 that rotates horizontally can pass through the gap. The position sensor 60 is turned off when light passes from the light projecting unit 62 to the light receiving unit 63, and is turned on when light is blocked by the sensor flag member 41.

  The position sensor 60 is not limited to the transmissive photosensor of the present embodiment described above. If a detector that rotates integrally with the punch member 21 such as the sensor flag member 41 is used, various known sensors such as a reflective photosensor, a magnetic sensor, and an ultrasonic sensor may be used. it can.

  FIG. 8 schematically shows a control configuration of the drilling system 100 of the present embodiment. The punching system 100 further includes a control unit 80 for controlling the punching operation of the sheet by the punching device 1. The control unit 80 includes a CPU 81 that controls the drive voltage applied to the drive motor 48, a memory 82 that stores information and data necessary for the punching process and its control, and a timer 83. In the present embodiment, the control unit 80 is provided in a main body device such as an image forming apparatus or a post-processing apparatus in which the punching system 100 is incorporated. In another embodiment, the control unit 80 can be provided in the drilling system 100 itself.

  The control unit 80 is connected to a motor drive circuit 85 connected between the drive motor 48 and its power source 84. The motor drive circuit 85 is provided with a short circuit having a suitable resistance between the terminals of the drive motor 48. The controller 80 can quickly stop the rotation of the drive motor 48 by connecting the short circuit.

  The control unit 80 is connected to the encoder 55 and the position sensor 60 of the punching device 1 and the first and second sheet sensors 86 and 87 provided in the punching system 100. As shown in FIG. 9A, the first sheet sensor 86 is arranged at a position on or slightly upstream of the carry-in rollers 105 and 106 along the sheet conveyance direction, and the second sheet sensor 87 is arranged on the carry-out roller 107. , 108 or between the position and the carry-in roller, the leading edge and / or trailing edge of the sheet conveyed through the guide path 104 is detected.

  Further, an input unit 88 provided in the main body device is connected to the control unit 80. The user can input information or data necessary for performing the drilling process by the drilling system 100 to the control unit 80 via the input unit 88. The control unit 80 causes the memory 82 to store information and data input by the user or sent from the main device side as necessary.

  Next, a series of operations for punching holes in the sheet S moving along the guide path 104 at a predetermined conveying speed by the punching system 100 of this embodiment and the control by the control unit 80 are shown in FIGS. The operation will be described with reference to the operational state diagram of FIG. 15 and the timing chart of FIG. 9 to 15 show a case where the sheet S is conveyed while being sandwiched between the pair of carry-in rollers 105 and 106 and the pair of carry-out rollers 107 and 108 at the same time. In FIG. 16, the horizontal axis represents time, and the vertical axis represents the drive voltage applied to the drive motor 48, the flag signal output from the position sensor 60, and the pulse signal output from the encoder 55.

  9A and 9B, the punching device 1 is located at the most upstream home position in the range of movement by the mounting unit 3. The punch member 21 and the cam member 31 are at the top dead center position that is the uppermost position in the axial direction, and the punching blade 22 stands by in the through hole 26 of the lower plate 16.

  In this standby state, when the leading edge of the sheet S conveyed on the guide path 104 is detected by the first or second sheet sensor 86, 87, the control unit 80 uses the timer 83 to determine the elapsed time thereafter. Start measurement. The controller 80 calculates the product of the measured elapsed time and the sheet conveyance speed of the carry-in roller 106 to thereby convey the sheet S from the position of the first or second sheet sensor 86, 87, that is, the sheet conveyance direction. Thus, the position of the sheet S can be accurately detected.

  When the sheet S reaches the punching operation start position set in advance in the sheet conveyance direction in the standby state, the control unit 80 operates the drive motor 48 to start the punching operation. As a result, the punch member 21 descends along the axial direction from the top dead center position together with the cam member 31 while rotating clockwise in FIG. 9B according to the profile of the cam groove 33. The start of lowering of the punch member 21 is detected by the control unit 80 when the position sensor 60 detects the end 41a of the sensor flag member 41.

  Further, in the standby state, the sheet pressing unit 70 is provided with a slight gap between the cam receiving unit 77 and the lower surface of the cam 31, and the sheet presser 78 is a sheet being conveyed through the sheet path 17 of the punching device 1. It is in contact with the upper surface of S. At this time, only a part of the weight of the leaf spring member 71 is applied to the upper surface of the sheet S, and the urging force is not acting at all. Accordingly, the sheet S is conveyed at a predetermined speed through the sheet path 17 without being substantially disturbed by the contact with the sheet presser 77. Further, even when no sheet is present in the sheet path 17, the sheet presser 78 is only in contact with the sheet support surface 14a, so that it is not hindered when the sheet is conveyed from the upstream side to the sheet path. .

  10A and 10B show a state where the punch member 21 and the cam member 31 are lowered so that the tip of the punching blade 22 reaches the lower end opening of the through hole 26, that is, the upper end position of the sheet passage 17. At this time, the punching device 1 is still held at the home position, and the sheet S continues to move in the sheet path 17 in the sheet conveyance direction A at a predetermined conveyance speed.

  At this time, in the leaf spring member 71, the cam receiving portion 77 of the upper spring plate portion 72 is slightly pushed down from the uppermost position in the standby state described above by the lower surface of the cam member 31. The pressing force acting on the sheet S from the sheet presser 78 has such a magnitude that the movement of the sheet is not substantially delayed or hindered since the displacement amount of the leaf spring member 71 is small.

  FIGS. 11A and 11B show a state in which the punch member 21 and the cam member 31 are further lowered, and the leading end of the punching blade 22 reaches the lower end position of the sheet path 17, that is, the upper surface of the sheet S. From this state, punching of the sheet S substantially starts when the punch member 21 further descends. The control unit 80 determines that the front end of the punching blade 22 has reached the upper surface of the sheet S based on the elapsed time after the detection of the front end of the sheet by the first or second sheet sensors 86 and 87 described above.

  In the state shown in FIG. 11A, the sheet S is supported by the sheet presser 78 with a relatively large pressing force by the cam presser 77 being further pushed down from the position shown in FIG. 14a. As a result, the sheet S immediately before punching is not displaced up and down in the sheet passage 17, so that the position of the sheet in the axial direction is always fixed and maintained at the same timing at the desired punch hole punching position of the sheet. You can start drilling.

  Further, a frictional force due to the pressing force from the sheet presser 78 is generated between the sheet presser 78 and the sheet support surface 14 a and the upper and lower surfaces of the sheet S. On the other hand, when the punching blade 22 starts to punch the sheet S, the peripheral surface on the upstream side of the punch member 21 is engaged with the peripheral edge of the punch hole just punched, and the punch member is moved downstream from the peripheral edge of the punch hole. Acting force is generated in the direction of pushing to the side. At substantially the same time, the frictional force generated between each surface of the sheet S and the sheet presser 78 and the sheet support surface 14a acts to pull the punching device 1 in the sheet conveying direction A.

  With these forces acting from the sheet S, the punching device 1 punches a punch hole while moving downstream at the same speed as the sheet against the urging force of the tension coil spring 122. At this time, the force necessary to move the punching device integrally with the sheet is that the area near the punch hole of the sheet S that is held between the sheet support surface 14a by the contact of the sheet presser 78 and the peripheral edge of the punch hole. And share. In particular, since the reaction force received by the punch hole periphery from the outer peripheral surface of the punch member can be reduced by the frictional force, the possibility of damage to the punch hole periphery is eliminated or greatly reduced. Further, since the punching device 1 does not require separate driving means and control means for moving together with the sheet S, it is easy to reduce the size.

  In the timing chart of FIG. 16, after the drive motor 48 is started from the standby state at time t1, the punch member 21 descends and the tip of the punching blade 22 contacts the upper surface of the sheet until punching is started at time t2. The time, that is, the time lag ΔT1 can be obtained in advance from the test result or the like. When the sheet conveyance distance obtained by multiplying the time lag ΔT1 by the sheet conveyance speed of the carry-in roller 106 is calculated backward from the planned position for punching holes on the sheet, the position of the sheet S where the punching operation should be started, that is, the punching operation start position is obtained. can get.

  Generally, the number and position of the binding holes formed in the file sheet are standardized for each sheet size. Therefore, when forming a standard binding hole in a standard dimension sheet, it is possible to calculate in advance a punching operation start position of each binding hole, that is, a punch hole, for each sheet dimension, and convert it into a table value. Such table values can be stored in the memory 82 of the control device in advance.

  The control unit 80 determines whether the sheet size and the number and position of the punch holes are in accordance with the standard or non-standard from the information and data sent from the input unit 88 and the main device side. In the case of the standard, the control unit 80 selects the sheet size in the sheet conveyance direction and the punching operation start position of all punch holes to be punched from the table values stored in the memory 82. When the sheet size or the number and / or position of punch holes are out of specification, the control unit 80 may calculate the punching operation start position of each punch hole from the time lag and the sheet conveyance speed before starting the punching operation. it can.

  The timing at which the sheet S reaches the punching operation start position is determined by the control unit 80 based on the elapsed time counted from the detection of the leading edge of the sheet by the first or second sheet sensor 86, 87. Control of the operation of punching the first punch hole in the sheet will be described below.

  FIGS. 17A to 17C show control when the punching operation start position is determined based on detection of the sheet leading edge by the first sheet sensor 86. In the drawing, P0 is a punching position by the punch member 21 (axial position of the punch member), P1 is a scheduled punching position of the first punch hole of the sheet S (center position of the punch hole), and D0 is a punch hole from the sheet leading end Sa. The distance to the scheduled punching position P1, D1 is the sheet conveyance distance at the time lag ΔT1 from the start of the drive motor to the start of punching, and L1 is the distance between the punching operation position P0 of the punch member 21 and the first sheet sensor 86. The distance D0 is larger than the sheet conveyance distance D1, and is set to D0> D1.

  At time t0, as shown in FIG. 17A, when the first sheet sensor 86 detects the sheet leading edge Sa, the control unit 80 starts measuring time by the timer 83. At time t1, as shown in FIG. 17B, the sheet S is transported to a position where the distance between the punch hole scheduled position P1 and the punching operation position P0 of the punch member 21 coincides with the sheet transport distance D1 at the time lag ΔT1. Then, the control unit 80 activates the drive motor 48 by applying a predetermined drive voltage. Thereby, the punch member 21 starts to descend in the axial direction while rotating.

  The sheet conveyance distance from time t0 to time t1 is L1 + ΔD1 = L1 + (D0−D1). When the sheet conveyance speed of the carry-in roller 106 is v1, the time ΔT0 from time t0 to time t1 is calculated by (L1 + ΔD1) / v1. Here, L1 is a fixed value, and D1 is a table value stored in the memory 82 after being converted into data from a prior test result or the like.

  Therefore, D0 is a table value stored in the memory 82 when the sheet size and the binding hole are in accordance with the standard. In this case, the time ΔT0 can also be calculated in advance and stored in the memory 82 as a table value. Even when the sheet size and the binding hole are out of the standard, D0 can be obtained from data or the like previously input to the input unit 88 by the user. Therefore, the control unit 80 can obtain the time ΔT0 from the table value in the memory 82 before starting the punching process, or can calculate the time ΔT0 based on the above-described formula.

  The sheet S is conveyed to a position where the punch hole punching scheduled position P1 coincides with the punching operation position P0 of the punch member 21, as shown in FIG. 17C, at time t2 when the time lag ΔT1 has elapsed from time t1. Here, the tip of the punching blade 22 comes into contact with the upper surface of the sheet S, and punching at the punch hole punching scheduled position P1 is started. Note that when D0 = D1, the start timing of the drive motor 48 is controlled in the same manner as when D0> D1, and the description thereof is omitted.

  18A to 18C, the first sheet sensor 86 detects the sheet leading edge Sa as in FIG. 17, but the distance D0 is shorter than the sheet conveyance distance D1, and D0 <D1 is set. In this case, the sheet conveyance distance from time t0 when the first sheet sensor 86 detects the sheet leading edge Sa as shown in FIG. 18A to time t1 when the drive motor 48 is activated as shown in FIG. 18B. Is L1−ΔD1 = L1− (D0−D1), which is shorter by the distance difference ΔD1 between D0 and D1. Accordingly, the time t1 at which the drive motor 48 is activated may be set earlier by the distance difference ΔD1 than the time at which the sheet front end Sa reaches the punching operation position P0. Further, assuming that a position preceding the actual sheet front end Sa by a distance difference ΔD1 downstream in the sheet conveying direction is assumed to be a virtual sheet front end Sa ′, it can be considered in the same manner as in FIGS. .

  Time ΔT0 from time t0 to time t1 is calculated by (L1−ΔD1) / v1. Since the sheet conveyance speed v1 of the carry-in roller 106 is constant, when the sheet size and the binding hole are in accordance with the standard, the time ΔT0 can be converted into data in advance and stored in the memory 82 as a table value. Even when the sheet size and the binding hole are out of the standard, D0 can be calculated based on the above-described formula from data or the like that the user inputs to the input unit 88 in advance.

  As shown in FIG. 18 (b), the controller 80 at time t1, until the position where the distance between the punch hole scheduled position P1 and the punching operation position P0 coincides with the sheet conveyance distance D1 at the time lag ΔT1, that is, virtual When the sheet S is conveyed to a position where the sheet front end Sa ′ coincides with the punching operation position P 0, the control unit 80 applies a predetermined drive voltage to activate the drive motor 48. Thereby, the punch member 21 starts to descend in the axial direction while rotating. Then, at time t2, as shown in FIG. 18C, when the sheet S is transported to a position where the punch hole punching scheduled position P1 coincides with the punching operation position P0, the tip of the punching blade 22 contacts the upper surface of the sheet S. Then, the punching at the punch hole drilling scheduled position P1 is started.

  FIGS. 19A to 19C show control when the punching operation start position is determined based on detection of the sheet leading edge by the second sheet sensor 87. In the drawing, the second sheet sensor 87 is disposed upstream of the carry-out roller 108 and downstream of the punch member 21 along the sheet conveyance direction. In the figure, L 2 is the distance between the punching operation position P 0 of the punch member 21 and the second sheet sensor 87.

  In FIGS. 19A to 19C, as in FIGS. 17A to 17C, the distance D0 is larger than the sheet conveying distance D1, and D0> D1 is set. Further, in FIGS. 19A to 19C, when the second sheet sensor 87 detects the sheet leading end Sa, the distance D0 and the sheet are set so that the punch hole scheduled position P1 is located upstream from the punching operation position P0. The transport distance D1 is set to D0 ≧ L2 + D1.

  At time t0, as shown in FIG. 19A, when the second sheet sensor 87 detects the sheet leading edge Sa, the control unit 80 starts measuring time by the timer 83. At time t1, as shown in FIG. 19B, the sheet S is transported to a position where the distance between the punch hole scheduled position P1 and the punching operation position P0 of the punch member 21 coincides with the sheet transport distance D1 at the time lag ΔT1. Then, the control unit 80 activates the drive motor 48 by applying a predetermined drive voltage. Thereby, the punch member 21 starts to descend in the axial direction while rotating.

  The sheet conveyance distance ΔD1 from time t0 to time t1 is ΔD1 = D0− (L2 + D1). Therefore, the time ΔT0 from time t0 to time t1 is calculated by ΔT0 = {D0− (L2 + D1)} / v1. Here, L2 is a fixed value.

  Therefore, when the sheet size and the binding hole are in accordance with the standard, the time ΔT0 can also be calculated in advance and stored in the memory 82 as a table value. Even when the sheet size and the binding hole are out of the standard, D0 is obtained from data or the like previously input to the input unit 88 by the user, so that the control unit 80 can calculate the time ΔT0 based on the above formula. it can.

  The sheet S is conveyed to a position at which the punch hole drilling scheduled position P1 coincides with the punching operation position P0 of the punch member 21, as shown in FIG. 19C, at time t2 when the time lag ΔT1 has elapsed from time t1. Here, the tip of the punching blade 22 comes into contact with the upper surface of the sheet S, and punching at the punch hole punching scheduled position P1 is started. Note that when D0 = D1, the start timing of the drive motor 48 is controlled in the same manner as when D0> D1, and the description thereof is omitted.

  In another embodiment, the second sheet sensor 87 can be disposed between the punch member 21 and the carry-in roller 106. In this case, the activation timing of the drive motor 48 is controlled in the same manner as in the case of FIG. 17 or FIG. 18 depending on the magnitude of the distance D0 and the sheet conveyance distance D1, and thus the description thereof is omitted.

  Next, control of the operation of punching the last punch hole in the sheet will be described below. After the sheet trailing edge Sb passes through the carry-in roller 106, the sheet S is conveyed at a higher speed than the carry-in roller 106 by the carry-out roller 108. Therefore, when the last punch hole is punched after the sheet trailing edge Sb passes the carry-in roller 106, it is necessary to adjust the start timing of the drive motor 48.

  In the present embodiment, the timing at which the drive motor 48 is started to punch the last punch hole is controlled based on the time measured by the timer 83, starting from the detection of the sheet leading edge Sa by the second sheet sensor 87. . Since the distance between the second sheet sensor 87 and the carry-in roller 106 is a fixed value, the time tz when the sheet rear end Sb passes through the carry-in roller 106 is known in advance from the total length Ls of the sheet S. The distance ΔDz between the punching operation position P0 of the punch member 21 at the time tz and the final punch hole scheduled position Pz is also known in advance.

  Accordingly, the time ΔTz during which the sheet S is transported from the time tz to the position where the final punch hole punching scheduled position Pz coincides with the punching operation position P0 is expressed as ΔTz = ΔDz / v2. On the other hand, the time lag ΔT1 from the start of the drive motor to the start of punching is constant regardless of the sheet conveyance speed. Therefore, when ΔTz ≧ ΔT1, the control unit 80 may start the drive motor 48 after the time (ΔTz−ΔT1) has elapsed from the time tz.

  In the case of ΔTz <ΔT1, a distance difference D1−ΔDz = ΔDz1 obtained by subtracting the distance ΔDz from the sheet conveyance distance D1 by the carry-in roller 106 is equal to the position of the distance D1 on the downstream side from the final punch hole scheduled position Pz of the sheet S. This is the distance transported by the carry-in roller 106 from the time point when the operating position P0 coincides to the time tz. The conveyance time ΔTz ′ by the carry-in roller 106 with the distance difference ΔDz1 is ΔTz ′ = ΔDz1 / v1. Therefore, the control unit 80 may activate the drive motor 48 earlier than the time tz by the time ΔTz ′.

  In another embodiment, based on detection of the sheet trailing edge Sb by the first sheet sensor 86, the timing at which the drive motor 48 is activated to punch the last punch hole can be controlled. FIGS. 20A to 20D show control when the punching operation start position is determined based on the time measured by the timer 83 with the detection of the sheet trailing edge Sb by the first sheet sensor 86 as a starting point. ing. In the drawing, Dz is the distance between the last punch hole punching scheduled position Pz and the sheet rear end Sb, and Lr1 is the distance between the punching operation position P0 of the punch member 21 and the carry-in roller 106. The distance L1 between the punching operation position P0 and the first sheet sensor 86 is set to be larger than the sum of the distance Dz and the sheet conveyance distance D1.

  As shown in FIG. 20A, when the first sheet sensor 86 detects the sheet trailing edge Sb at time tz0, the control unit 80 starts measuring time by the timer 83. As shown in FIG. 20B, the sheet S is conveyed to the speed v1 by the carry-in roller until time tz01 when the sheet rear end Sb passes through the carry-in roller 106, and thereafter is conveyed by the carry-out roller 108 at the speed v2. The If the sheet transport time from time tz0 to time tz01 is ΔTz1, time tz01 is tz01 = tz0 + ΔTz1 = tz0 + (Lr1 / v1).

  The sheet conveyance speed v2 of the carry-out roller 108 is faster than the sheet conveyance speed v1 of the carry-in roller 106, and the time lag ΔT1 from the start of the drive motor to the start of punching is constant regardless of the sheet conveyance speed. Accordingly, in FIG. 20C, the timing for driving the drive motor 48 is set earlier than the case where the drive motor 48 is transported by the carry-in roller 106, that is, at a distance D1 + ΔD1 ′ downstream from the final punch hole scheduled position Pz. Must. Here, the distance ΔD1 ′ is an adjustment distance that is added when the sheet conveyance speed increases from v1 to v2.

  The distance between the drilling operation position P0 and the punch hole drilling scheduled position Pz in FIG. 20B is L1-Lr1-Dz. Therefore, if the sheet conveyance time from FIG. 20B to FIG. 20C is ΔTz2, ΔTz2 = {L1−Lr1−Dz− (D1 + ΔD1 ′)} / v2. Here, the distance D1 + ΔD1 ′ is (ΔT1−ΔTz1) × v2 + Lr1, and can be calculated before the punching process of the sheet S is started.

  Therefore, the time tz1 = tz01 + ΔTz2 at which the drive motor 48 is activated in FIG. 20C is calculated from data from a prior test result and the like and stored in the memory 82 as a table value when the sheet size and the binding hole comply with the standard. I can leave it to you. Further, when the sheet size and the binding hole are out of the standard, it can be calculated in advance based on the data obtained from the input unit 88 and / or the apparatus main body before the punching process is started.

  As shown in FIG. 20C, the control unit 80 applies a predetermined drive voltage to start the drive motor 48 at the time tz1 that is converted into a table value or calculated as described above. Then, at time tz2, as shown in FIG. 20 (d), the sheet S is conveyed to a position where the punch hole punching scheduled position Pz coincides with the punching operation position P0, and the tip of the punching blade 22 contacts the upper surface of the sheet S. Drilling is started at the punch hole drilling scheduled position Pz.

  As described above, in the present embodiment, the two sheet sensors 86 and 87 are arranged on the upstream side and the downstream side of the pair of carry-in rollers 105 and 106. However, as can be seen from the above description, one of the sheet sensors can be omitted, and it is preferable to leave the second sheet sensor 87 on the downstream side.

  12A and 12B, the punch member 21 and the cam member 31 are lowered to the bottom dead center position, the punching blade 22 enters the lowest position in the die hole 28, and a punch hole is formed in the sheet S. Shows the state. After this, the drive motor 48 continues to rotate, so that the punch member 21 rises in the axial direction from the bottom dead center position while rotating, and detaches upward from the punch hole to penetrate the lower plate 16. The return process of returning to the standby position in the hole 24 is started.

  When the punch member 21 reaches the bottom dead center position, the pressing force from the leaf spring member 71 to the sheet S, and thus the frictional force between the sheet S and the sheet presser 78 and the sheet support surface 14a is maximized. Until the punch member 21 is completely removed from the punch hole, the punching device 1 is configured to apply the acting force from the punch hole periphery to the punch member outer peripheral surface, and between the sheet pressing and sheet support surfaces and the sheets S. The frictional force keeps moving together with the sheet S.

  13A and 13B show a state in which the sheet S has reached the lower end position of the sheet path 17 from the bottom dead center position, that is, the upper surface of the sheet S, from the bottom dead center position. In this state, the punch member 21 is completely detached from the punch hole and released from the engagement with the punch hole.

  While the punch member 21 is engaged with the punch hole, the sheet S is subjected to the reaction force of the acting force that the peripheral edge of the punch hole receives from the outer peripheral surface of the punch member 21 and the sheet conveying force of the pair of carry-in rollers 105 and 106. , Acting in the direction opposite to each other in the sheet conveying direction. On the other hand, the sheet passage 17 of the punching device 1 has a predetermined height to allow sheets of various thicknesses to pass smoothly. Therefore, when the sheet S is thin or soft and has low rigidity, for example, as indicated by an imaginary line S ′ in FIG. 12A, the sheet S is placed between the punch member 21 and the pair of carry-in rollers 105 and 106 in the sheet path 17. There is a risk of slack in the height direction.

  In the present embodiment, as described above, the sheet conveyance speed of the pair of carry-out rollers 107 and 108 is set faster than the sheet conveyance speed of the pair of carry-in rollers 105 and 106. Therefore, at the same time when the punch member 21 is released from the engagement with the punch hole, the unloading roller pair 107, 108 keeps the sheet S between its upper and lower surfaces until the height direction is eliminated. It can be transported without slipping. Meanwhile, the pair of carry-in rollers 105 and 106 continue to convey the sheet at the same speed, so that the position of the punch hole formed by the next punching operation can be controlled with high accuracy. Therefore, it is possible to position and punch a plurality of punch holes continuously with high accuracy.

  Also in the returning process, the sheet S is pressed against the sheet support surface 14a by the leaf spring member 71 until the tip of the punching blade 22 reaches the upper surface of the sheet from the bottom dead center position. Thereby, the punch member 21 can be detached from the punch hole in a very short time. Therefore, even when the sheet S is conveyed at a high speed, the possibility that the edge of the punching blade 22 touches the periphery of the punching edge 22 when it comes out of the punched hole or deteriorates the quality of the punched hole is eliminated or greatly reduced. The

  Further, a sufficient pressing force similar to that in the punching process is applied to the sheet S from the leaf spring member 71 until at least the tip of the punching blade 22 reaches the upper surface of the sheet from the bottom dead center position. Therefore, the frictional force necessary for moving the punching device 1 can be generated between the sheet presser and the sheet support surface.

  In the timing chart of FIG. 16, at the time t3, the control unit 80 cuts off the power supply from the power source 84 to the drive motor 48 and connects the short circuit in the motor drive circuit 85 at the same time as the punch member 21 leaves the punch hole. Thus, the rotation of the drive motor 48 is braked. By controlling the drive of the drive motor 48 in this way, the time T0 from the time t2 to the time t3 when the punch member 21 is engaged with the punch hole of the sheet S can be minimized. Thereby, the possibility of damage to the punch hole due to the cutting edge of the punching blade 22 and the deterioration of the quality can be more reliably eliminated or further reduced.

  The time t3 at which the punch member 21 is released from the punch hole is based on the elapsed time counted from the detection of the leading edge of the sheet by the first or second sheet sensor 86, 87 as in the above-described punching operation start position. The control unit 80 determines. The time T0 from when the punch member 21 starts drilling at time t2 to when the punch member 21 leaves the punch hole at time t3 can be obtained in advance from the test result or the like. Therefore, it is easy to calculate the time t3 by adding the time lag ΔT1 and the time T0 to the time t1.

  Until the drive motor 48 is completely stopped at time t4 from the start of braking at time t3, the punch member 21 continues to rise in the axial direction at a reduced speed due to inertial rotation of the drive motor. As shown in FIGS. 14 (a) and 14 (b), the punch member 21 has the tip of the punching blade 22 passing through the lower end opening of the through hole 26, that is, the upper end position of the sheet passage 17, and is shown in FIGS. 15 (a) and 15 (b). Thus, it reaches the top dead center position and stops at a predetermined position together with the drive motor 48.

  As can be seen from FIGS. 9A to 14A, the cam groove 33 of the present embodiment has one cam crest for the punch member 21 to perform a punching operation between the standby position and the standby position. It is only provided. Accordingly, even when braking of the drive motor 48 is started when the punch member 21 leaves the punch hole, the punch member 21 is stopped at a standby position with a sufficient margin, that is, without entering the next drilling process. Can do.

  Similarly, the time lag ΔT2 from when the driving motor 48 starts braking at time t3 until it completely stops at time t4 can be obtained in advance from the test results, and therefore time t4 can be easily calculated in advance. These times t2, t3, t4, time lags ΔT1, ΔT2, and time T0 can be stored in advance as table values in the memory 82, and by reading these from the memory 82 as appropriate, the control unit 80 can drive the drive motor. The drive of 48 can be controlled easily and accurately.

  When the punch member 21 is detached from the punch hole and the engagement between the outer peripheral surface and the punch hole periphery is released, the punching device 1 quickly moves horizontally by the urging force of the tension coil spring 122, and Returned to home position. Since the time for the punch member 21 to leave the punch hole is very short, the punching device can be automatically returned to the home position more quickly.

  On the other hand, the sheet S continues to move along the sheet conveyance direction A at a predetermined conveyance speed. The pressing force from the leaf spring member 71 decreases as the punch member 21 and the cam member 31 are raised, and even if the sheet presser 78 is in contact with the upper surface of the sheet after the punch member 21 is detached from the punch hole, The conveyance of the sheet S is not delayed or hindered.

  When the punch member 21 reaches the top dead center position and stops at the predetermined position, the punch member 21 enters a standby state in preparation for the next drilling operation. The controller 80 determines the timing for entering the next drilling operation on the basis of the time t4 when the punch member 21 stops and the stop position.

  In another embodiment, the conveyance amount of the sheet S, that is, the sheet position in the sheet conveyance direction, can be accurately determined by the rotation amount of the drive motor 120 of the sheet conveyance mechanism 101. For example, the drive motor 120 is provided with an encoder, and a pulse signal output from the encoder is counted by the timer 83 to detect the rotation amount of the drive motor 120. The control unit 80 causes the timer 83 to start counting pulse signals received from the encoder of the drive motor 120 at the same time when the first or second sheet sensor 86 or 87 detects the leading edge of the sheet S. The conveyance count of the sheet S is calculated by converting the pulse count value with a coefficient obtained in advance from a test result or the like.

  In another embodiment, the timing at time t3 when the control unit 80 connects the short circuit and brakes the rotation of the drive motor 48 can be determined by the amount of rotation of the drive motor 48. The rotation amount of the drive motor 48 is detected by the encoder 55 as described above, and is sent to the control unit 80. The control unit 80 causes the timer 83 to start counting the pulse signals sent from the encoder 55 simultaneously with the detection of the sheet leading edge by the first or second sheet sensor 86, 87.

  The number of count pulses corresponding to time t3 can be obtained in advance from the test result or the like. The number of count pulses corresponding to other times t2, t4, time lags ΔT1, ΔT2 and time T0 can also be obtained in advance from the test results and the like. By storing these count pulse numbers in advance in the memory 82 as table values and reading them out as appropriate, the control unit 80 can perform drive control of the drive motor 48 easily and accurately.

  In the present embodiment, the driving motor 48 is rotated only in the forward rotation direction, and the punch member 21 is driven while rotating in one direction (clockwise in the present embodiment), thereby continuously performing the punching operation. The control unit 80 considers the operation time (or rotation amount) of the drive motor 48 from the stop position of the punch member 21 described above until the punch member 21 starts to descend in the axial direction from the standby position in the next drilling process. Thus, the timing for starting the drive motor 48 again is determined. The timing for restarting the drive motor 48 can also be converted into a table value and stored in the memory 82 in advance if it can be obtained from the test result or the like in advance.

  In another embodiment, the drilling operation can be continuously performed by reversing the direction of rotation of the drive motor 48 every time one drilling operation is completed. In this case, the punch member 21 also rotates alternately in the clockwise direction and the counterclockwise direction corresponding to the rotation direction of the drive motor 48. In this case, it is preferable to determine the axial position (or rotational position) of the punch member 21 based on the rotation amount of the drive motor 48, that is, the number of count pulses output from the encoder 55, and to control the drive motor 48. .

  In yet another embodiment, the timing for starting braking of the drive motor 48 can be determined by an on / off flag signal output from the position sensor 60. In this case, the sensor flag member 41 may be provided so that the rising and falling edges of the flag signal coincide with the timing of the punching start of the punch member 21 and the punch hole removal. Thereby, the timing of the braking start of the drive motor 48 can be directly determined from the operation of the punch member 21 being detached from the punch hole.

  In another embodiment, in the sheet conveying mechanism 101, the belt transmission mechanism including the pulleys 115 and 116 and the belt 117 is omitted, and the driving-side carry-in roller 106 and the carry-out roller 108 are respectively driven by dedicated drive motors. Can do. In this case, the control unit 80 separately controls the drive motors so that the rotation speed of the carry-out roller 108, that is, the sheet conveyance speed is faster than the rotation speed of the carry-in roller 106, that is, the sheet conveyance speed.

  In particular, the standardized binding holes for files include the center position of the first hole (and / or the final hole) and the distance between the sheet edges adjacent thereto, that is, the sheet edge-to-hole distance, and the distance between each hole center (hole (Pitch) is determined in advance in length units (for example, millimeters). On the other hand, when the rotation amount of the drive motor 120 is pulse-controlled as described above, the number of pulses required for one rotation of the drive motor is an integer value, whereas the carry-in roller 106 and the carry-out roller 108 driven thereby. The sheet feed amount per pulse is calculated in radians. Therefore, when the sheet end-to-hole distance and the hole pitch are converted into the number of pulses of the drive motor 120, in many cases, a fraction after the decimal point occurs.

  However, in practice, the control unit 80 commands the number of pulses (integer value) to control the rotation amount of the drive motor 120, so that a desired sheet conveyance amount (that is, the sheet end-hole distance and hole pitch). There is a possibility that an error smaller than the sheet feed amount for one pulse may occur between the actual sheet transport amount and the actual sheet transport amount. If this error is accumulated for each punch hole, the actual punch hole may be greatly deviated from the punch hole scheduled position before or after the last punch hole, and the sheet may be bound into a desired file. The problem of not being able to occur.

  Therefore, in still another embodiment of the present invention, in order to eliminate the occurrence of such a problem, a command output by the control unit 80 corresponding to the sheet end-hole distance and the hole pitch as described below. The number of pulses is adjusted to control the sheet conveyance amount for each punch hole. FIG. 21 shows a sheet S in which a plurality (n) of punch holes are continuously punched along one side (length Ls).

  In the figure, H1 to Hn indicated by imaginary lines virtually indicate punch holes formed at desired drilling scheduled positions P1 to Pn, respectively. d0 to dn are a sheet end-hole distance between a desired first hole and a final hole, and a hole pitch (unit: for example, millimeter) between adjacent punch holes. k0 to kn are temporary feed pulse numbers obtained by dividing d0 to dn by a sheet feed amount f (unit: millimeters) per pulse to the decimal point (for example, two digits), and K0 to Kn are k0 to kn. Is the actual number of feed pulses adjusted to an integer value. Q1 to Qn indicate punch hole punching positions (hole center positions) when the sheet is conveyed according to the actual feed pulse numbers K0 to Kn.

  First, for all the punch holes H1 to Hn, the provisional feed pulse numbers k0 to kn corresponding to the sheet end-hole distance and the hole pitches d0 to dn are adjusted to an integer, and the provisional feed pulse numbers K0 to Kn are provisionally set. Is derived. The adjustment to the integer is performed, for example, by rounding off the fractions after the decimal point of the temporary feed pulse numbers k0 to kn. Here, it is preferable that the adjustment range of the rounding up or down with respect to the temporary feed pulse numbers k0 to kn is less than 0.5. When the fraction after the decimal point is 0.50, in this embodiment, it is rounded up by rounding off.

  Thus, the actual sheet end-to-hole distances q0 and qn between the punch hole drilling positions Q1 and Qn of the first hole H1 and the final hole Hn and the sheet ends Sa and Sb adjacent thereto are determined. Subtract the distances q0 and qn from the total sheet length Ls and divide this by the sheet feed amount f per pulse to calculate the total number of feed pulses K (1, n-1) allocated between the punch holes H1 to Hn. To do. This total feed pulse number K (1, n-1) is compared with the sum of the provisional feed pulse numbers K1 to Kn-1 between the punch holes derived earlier. In the case of coincidence, the feed pulse numbers K0 to Kn provisionally derived earlier are determined as the actual feed pulse numbers.

  If they do not match, the number of differences in the total number of feed pulses is selected and distributed from the provisional number of feed pulses K1 to Kn-1 between the punch holes by the same number as that of the difference. The number of pulses assigned to the individual feed pulse numbers K1 to Kn-1 is +1 or -1. In this distribution, the difference between the punch hole drilling positions Q2 to Qn-1 determined by the number of feed pulses K1 to Kn-1 after distribution and the desired drilling scheduled positions P2 to Pn-1 is converted into the number of pulses. It is preferable to set it to be less than +/− 0.5.

  Thus, according to the present embodiment, the deviation between the desired drilling scheduled positions P1 to Pn and the punch hole drilling positions Q1 to Qn determined by the actual feed pulse numbers K0 to Kn is converted into the number of pulses. It can be suppressed within a sheet conveying distance of 1/2 pulse. As a result, all the punch holes can be actually drilled within a minimum deviation from the positions of the desired punch holes H1 to Hn.

  According to the modification of the present embodiment, the actual number of feed pulses K0 to Kn can be determined as follows. First, similarly, for all punch holes H1 to Hn, provisional feed pulse numbers k0 to kn corresponding to the sheet end-hole distance and the hole pitches d0 to dn are adjusted to an integer to tentatively feed pulse numbers K0. ~ Kn is derived. Since the integerization is adjusted in the same manner as described above, description thereof is omitted.

  Next, a punch hole punching position Q2 corresponding to the feed pulse number K1 of the second hole H2 is derived with reference to the punch hole punching position Q1 corresponding to the feed pulse number K0 of the first hole H1. The punch hole punching position Q2 corresponds to the feed pulse number K1 in units of pulse number by adding the feed pulse number K1 to the feed pulse number K0 or the distance q0 from the sheet edge Sa to the punch hole punching position Q1. By adding the sheet conveyance distance (= K1 × f), it can be derived in length units.

  At this time, it is determined whether the deviation between the punch hole punching position Q2 and the desired scheduled punching position P2 is less than 1/2 pulse or less than the corresponding sheet conveyance distance. If so, the provisional feed pulse number K1 is determined as the actual feed pulse number. Otherwise, 1 is added to or subtracted from the provisional feed pulse number K1, and the punching hole drilling position Q2 is derived again, and the deviation from the desired drilling scheduled position P2 is less than 1/2 pulse or a sheet corresponding thereto. Adjust so that it is less than the transport distance. Then, the number of feed pulses obtained by adding or subtracting 1 to the provisional number of feed pulses K1 is determined as the actual number of feed pulses.

  Similarly, for all remaining punch holes from the third hole to the final hole, the provisional feed pulse numbers K2 to Kn-1 are similarly adjusted to determine the actual feed pulse number. In this way, with respect to all punch holes, the deviation between the desired scheduled drilling positions P1 to Pn and the punch hole drilling positions Q1 to Qn due to the actual feed pulse numbers K0 to Kn is reduced to 1/2. The deviation from the position of the desired punch holes H1 to Hn can be suppressed within a minimum range within the range of the sheet conveyance distance for the pulse.

  In any case, the determined actual feed pulse numbers K0 to Kn are calculated in advance and converted into data and stored in the memory 82 in advance as table values if the sheet dimensions and the binding holes are in accordance with the standard. Can do. Further, even when the sheet size and the binding hole are out of specification, the memory is calculated before the punching operation is started by the above-described method based on the data obtained from the input unit 88 and / or the apparatus main body before the punching process is started. 82 can be stored.

  In addition, the above-described process of controlling the rotation of the drive motor 120 in consideration of the deviation between the desired punching scheduled position and the actual punching position of the punch hole is not limited to the present embodiment and its modifications. . Various other processes can be considered as long as the deviation between the scheduled punching position and the actual punching position is suppressed within the range of the sheet conveyance distance of 1/2 pulse in terms of the number of pulses of the drive motor 120. Will be apparent to those skilled in the art.

  As mentioned above, although this invention was demonstrated in relation to preferred embodiment, this invention is not limited to the said embodiment, In the technical scope, it can implement by adding various change or deformation | transformation. Needless to say. For example, as long as the punching apparatus includes a punch member that reciprocates in the vertical direction with respect to a horizontally conveyed sheet, various configurations other than the above-described embodiment can be applied.

DESCRIPTION OF SYMBOLS 1 punching apparatus 2 frame 3 mounting unit 4 support member 5 movable mounting member 11 punching part 12 drive part 13 frame structure 14 lower frame 14a sheet support surface 15 upper frame 16 lower plate 17 sheet path 18, 20 side plate 19 upper plate 21 Punch member 22 Drilling blade 22a Bottom top portion 28 Die hole 31 Cam member 33 Cam groove 34 Cam pin 41 Sensor flag member 42 Driven gear 48 Drive motor 50 Drive gear 53 Warm 55 Encoder 60 Position sensor 70 Sheet pressing portion 71 Leaf spring member 75 Shaking Moving arm 77 Cam receiving portion 78 Sheet pressing 80 Control portion 86 First sheet sensor 87 Second sheet sensor 100 Punching system 101 Sheet conveying mechanism 102 Upper guide plate 103 Lower guide plate 104 Guide paths 105 and 10 Carrying roller 107 and 108 carry-out roller 120 driving motor

Claims (18)

A punch member having a perforation blade at one end in the axial direction and reciprocating in the axial direction;
A drive motor for reciprocating the punch member in the axial direction so that a punch hole is punched by the punching blade in a sheet transported in a predetermined transport direction;
A control unit for controlling the drive motor,
The punch member is movable together with the sheet in the predetermined conveying direction by engagement with the punch hole being punched;
Timing at which the control unit activates the drive motor based on a sheet conveyance amount linked to a displacement amount of the punch member until the punching blade starts to punch the punch hole after the drive motor is activated. To control the perforation system.   The punching system according to claim 1, wherein the transport amount of the sheet is a length in the predetermined transport direction starting from a leading end of the sheet.   The sensor further comprises a sensor for detecting the leading edge of the sheet, and the control unit determines the timing for starting the drive motor with the detection of the leading edge of the sheet output from the sensor as a starting point. Drilling system as described in.   The drilling system according to any one of claims 1 to 3, wherein the control unit determines a displacement amount of the punch member based on a rotation time after the drive motor is started.   The drilling system according to any one of claims 1 to 3, wherein the control unit determines a displacement amount of the punch member based on a rotation amount after the drive motor is activated.   The punch member reciprocates in the axial direction while rotating about the axis thereof to punch a punch hole in the sheet, and the control unit determines the rotation position of the punch member after the drive motor is activated. The drilling system according to claim 1, wherein a displacement amount of the punch member is determined.   In order to convey the sheet in the predetermined conveying direction, the sheet further includes a conveying roller pair disposed on the upstream side of the punch member and a conveying roller pair disposed on the downstream side, and the upstream conveying roller pair The nip pressure is larger than the nip pressure of the downstream conveying roller pair, and the sheet conveying speed of the downstream conveying roller pair is faster than the sheet conveying speed of the upstream conveying roller pair. A perforation system according to crab.   The drilling system according to claim 7, wherein a friction coefficient of a roller surface of the downstream conveyance roller pair is smaller than a friction coefficient of a roller surface of the upstream conveyance roller pair.   In order to convey the sheet in the predetermined conveyance direction, a conveyance roller pair arranged on the upstream side and / or downstream side of the punch member, and conveyance that drives the conveyance roller pair under pulse control by the control unit A drive motor, and a plurality of punch holes are formed in the sheet. In this case, a deviation between a desired drilling position of the plurality of punch holes and an actual drilling position is ½ by the conveyance drive motor. The punching system according to any one of claims 1 to 6, wherein the control unit controls the conveyance drive motor so that the sheet conveyance amount within a pulse is within a range. A punch member having a punching blade at one end in the axial direction, and a punch member capable of reciprocating in the axial direction, and the punch member so as to punch holes in the sheet transported in a predetermined transport direction by the punching blade. A punching system control method comprising: a drive motor that reciprocates in the axial direction, wherein the punch member is movable together with the sheet in the predetermined conveying direction by engagement with the punch hole being punched. ,
Drilling for controlling the timing of starting the drive motor based on the sheet conveyance amount linked to the displacement amount of the punch member until the punching blade starts to punch the punch hole after starting the drive motor System control method.   The punching system control method according to claim 10, wherein the transport amount of the sheet is a length in the predetermined transport direction starting from a leading end of the sheet.   The punching system control method according to claim 11, wherein the leading edge of the sheet is detected before starting the driving motor, and the timing for starting the driving motor is determined with the detection of the leading edge of the sheet as a starting point.   The drilling system control method according to any one of claims 10 to 12, wherein a displacement amount of the punch member is determined based on a rotation time after activation of the drive motor.   The drilling system control method according to any one of claims 10 to 12, wherein a displacement amount of the punch member is determined based on a rotation amount after activation of the drive motor.   The punch member reciprocates in the axial direction while rotating about the axis thereof to punch punch holes in the sheet, and the displacement amount of the punch member depends on the punch member after the drive motor is activated. The drilling system control method according to any one of claims 10 to 12, which is determined by a rotational position.   In order for the punching system to transport the sheet in the predetermined transport direction, a pair of transport rollers disposed on the upstream side and / or downstream side of the punch member, and the transport roller is pulse-controlled by the control unit. A conveyance drive motor for driving the pair, and in order to form a plurality of punch holes in the sheet, a shift between a desired drilling position and an actual drilling position of the plurality of punch holes is caused by the conveyance drive. The perforation system control method according to any one of claims 10 to 15, wherein the rotation of the conveyance drive motor is controlled so as to be within a range of a sheet conveyance amount for 1/2 pulse by the motor.   A sheet processing apparatus comprising the punching system according to claim 1.   An image forming apparatus comprising the punching system according to claim 1 or the sheet processing apparatus according to claim 17.

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