JP6687419B2 - Punching system, control method thereof, sheet processing apparatus and image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punching system for automatically punching files or other punched holes in various sheet-shaped workpieces such as a paper sheet, a plastic sheet, a metal sheet, and a cloth sheet, and a control method thereof. Further, the present invention relates to a sheet processing apparatus and an image forming apparatus provided with such a punching system.

  Conventionally, it is mounted on an image forming apparatus such as a copying machine, a printing machine, a facsimile machine, a post-processing apparatus, a bookbinding apparatus, etc., and a binding hole for a file is automatically formed on a sheet such as a paper sheet carried out from the apparatus. A piercing device is used for piercing. For example, there is known a punching device which punches a plurality of punch holes in a sheet by vertically reciprocating a plurality of punch members in a punching direction by a drive motor (see, for example, Patent Documents 1 and 2).

  The punching devices described in Patent Documents 1 and 2 are provided with a drive rotating shaft that transmits the forward and reverse rotations of the drive motor to a plurality of punch members, and the rotation of the drive rotating shaft is rotated by a gear mechanism and a cam mechanism. And a linear reciprocating motion in the axial direction to perform a punching operation for a plurality of punch holes. The number of punch holes to be punched in one sheet is selected by controlling the rotation direction and the rotation range of the drive rotary shaft to select a group of punch members to be punched, whereby two or four holes (or 3 holes) and so on.

  In the punching device of Patent Document 2, when the punch member is in the standby position at the top dead center and the rotation position of the drive rotation shaft is used as a reference position and the drive motor is normally rotated from the reference position, the punch members in the first group are punched. When operated and reversed, the punch members of the second group perform a punching operation. The rotation direction of the drive motor is controlled based on ON / OFF signals from the first and second flag sensors that detect the positions of the first and second flags that rotate integrally with the drive rotation shaft.

JP2012-228770A JP, 2013-116535, A

  When the power of the image forming apparatus or the sheet processing apparatus on the main body side is cut off for some reason, the punching device mounted therein stops in the state where the drive rotary shaft and each punch member are cut off. When the power is turned on again, the punch member of the punching device is once returned from the stop position when the power is cut off to the standby position at the top dead center.

  In the above-described conventional punching device, the drive rotation shaft is controlled so as to be located at the reference position during the initialization operation of the punching device. Therefore, in order to return the drive rotating shaft to the reference position when the power is turned on again, the drive rotating shaft has to be rotated at most one rotation at the stop position when the power is shut off. Therefore, there is a problem that it takes a long time to return the punching device to the state where the punching operation can be started.

Therefore, the present invention has been made in view of the above-mentioned problems of the conventional technology, and an object thereof is to shorten the startup time from the power-on after power-off to the state in which the punching operation can be started to a minimum. However, it is another object of the present invention to provide a drilling system having improved productivity and a control method thereof.
A further object of the present invention is to provide a sheet processing apparatus and an image forming apparatus provided with such a punching system.

The drilling system of the present invention, in order to achieve the above object,
A plurality of punch members that reciprocate between a punching position and a standby position to punch a sheet,
A drive motor capable of rotating in the forward and reverse directions for driving the plurality of punch members,
A rotary drive shaft that transmits the rotation of the drive motor to the plurality of punch members;
A plurality of sensor flag members that rotate integrally with the rotary drive shaft,
A plurality of position sensors that are provided in the same number as the plurality of sensor flag members and detect the corresponding sensor flag members , respectively.
A control unit for controlling the rotation of the drive motor,
Within one rotation of the rotary drive shaft, a plurality of operating positions in which at least one of the punch members is performing a punching operation, and the same number of home positions as the plurality of operating positions in which all of the punch members are in the standby position. And are provided alternately ,
One of the sensor flag members has a plurality of flag portions corresponding to the plurality of operating positions and the home position, and the plurality of flag portions are respectively provided at both ends in the rotation direction when the one sensor flag member is rotated. said detected by position sensor corresponding to the one sensor flag member has an edge portion off are provided to switch the output signal, and the edge portion of said plurality of flag unit, each of the Arranged to correspond to a boundary between a plurality of operating positions and the home position adjacent thereto,
The remaining sensor flag member has one flag portion corresponding to the one different operating position and the home position adjacent thereto, and the one flag portion has the remaining sensor at both ends in the rotation direction. When the flag member is rotated, the flag sensor has an edge portion which is detected by the position sensor corresponding to each of the remaining sensor flag members to switch ON / OFF of the output signal, and the edge portion of the one flag portion is Are arranged so as to correspond to the boundaries between the one operating position and the home position adjacent thereto, and the operating position and the home position adjacent to them.
The control unit detects a rotational position of the rotary drive shaft based on output signals of the plurality of position sensors.

  According to the present invention, by configuring the sensor flag member and the position sensor in this way, the control unit can easily determine which working position or home position the rotary drive shaft is. As a result, when the punch member is stopped at any of the operating positions, the punch member can be moved to the adjacent home position in a shorter time to prepare for the next punching process. When stopped at the home position, it is possible to prepare for the next punching process without moving the punch member as it is.

  In one embodiment, one revolution of the rotary drive shaft alternates between two actuated positions and two home positions, and a plurality of sensor flag members correspond to the two actuated positions and the two home positions. It comprises a first sensor flag member having one flag portion and a second sensor flag member having one flag portion corresponding to one of the two operating positions and one of the two home positions adjacent thereto. Since the number of operating positions and the number of home positions are each two, it is easy to determine the rotational position of the rotary drive shaft and control the drive motor.

  In another embodiment, the punch member reciprocates between the punching position and the standby position in the axial direction while rotating about the axis of the punch member to punch the sheet, and the punch member rotates once and the rotary drive shaft rotates once. Is supported. This makes it possible to more clearly understand the relationship between the movement of the punch member and the rotation of the rotary drive shaft.

  In another embodiment, the position sensor is a transmissive photo sensor. This type of photosensor has been widely used from the past, and can secure a stable control function.

Further, the drilling system control method of the present invention,
A plurality of punch members that reciprocate between a punching position and a standby position to punch a sheet,
A drive motor capable of rotating in the forward and reverse directions for driving the plurality of punch members,
A rotary drive shaft that transmits the rotation of the drive motor to the plurality of punch members;
A plurality of sensor flag members that rotate integrally with the rotary drive shaft,
The same number as the plurality of sensor flag members is provided, and a plurality of position sensors for detecting the corresponding sensor flag members are provided,
Within one rotation of the rotary drive shaft, a plurality of operating positions in which at least one of the punch members is performing a punching operation, and the same number of home positions as the plurality of operating positions in which all of the punch members are in the standby position. And are provided alternately ,
One of the sensor flag members has a plurality of flag portions corresponding to the plurality of operating positions and the home position, and the plurality of flag portions are respectively provided at both ends in the rotation direction when the one sensor flag member is rotated. said detected by position sensor corresponding to the one sensor flag member has an edge portion off are provided to switch the output signal, and the edge portion of said plurality of flag unit, each of the Arranged to correspond to a boundary between a plurality of operating positions and the home position adjacent thereto,
The remaining sensor flag member has one flag portion corresponding to the one different operating position and the home position adjacent thereto, and the one flag portion has the remaining sensor at both ends in the rotation direction. When the flag member is rotated, the flag sensor has an edge portion which is detected by the position sensor corresponding to each of the remaining sensor flag members to switch ON / OFF of the output signal, and the edge portion of the one flag portion is In one of the operating positions and the home position adjacent thereto, and a drilling system arranged so as to correspond to a boundary between the operating position and the home position adjacent to them,
The rotation position of the rotary drive shaft is determined based on the output signals of the plurality of position sensors.

  According to the present invention, it is possible to easily determine which working position or home position the rotational position of the rotary drive shaft is based on the output signals of the plurality of position sensors. Therefore, after the punching process is completed, or when the punching process is interrupted, the punching system can be brought into a state in which the next punching process can be started in a shorter time or in a state in which the punching process can be restarted.

  In one embodiment, when it is determined from the on / off signals output from the plurality of position sensors that the punch member is stopped at the operating position, the punch member is moved to the home position adjacent to the operating position. And control the drive motor. As a result, the next punching process can be started in a shorter time.

  According to another aspect of the present invention, the above-described punching system of the present invention is provided, whereby the start-up time from power-on after power-off to the state in which the punching operation can be started is shortened to a minimum, and production is performed. Provided is a sheet processing apparatus having improved property.

  According to another aspect of the present invention, the above-described punching system of the present invention or the above-described sheet processing apparatus of the present invention is provided, whereby a punching operation on a sheet after image formation can be started. There is provided an image forming apparatus in which the start-up time is shortened to the minimum and the productivity is improved.

1 is an overall configuration diagram of an image forming apparatus and a sheet post-processing apparatus to which the present invention is applied. FIG. 3 is a perspective view of a punching device according to the present invention. The front view of the punching device of FIG. The top view of the punching device of FIG. The side view which shows the drive mechanism of the punching apparatus of FIG. FIG. 6 is an enlarged sectional view taken along line VI-VI of FIG. 2. (A), (b) figure is explanatory drawing of the punching operation | movement of a punch member. The development view of the cylindrical cam of each punch member. (A), (b) figure is explanatory drawing which shows the positional relationship of a 1st, 2nd sensor flag member and a 1st, 2nd position sensor. Explanatory drawing which shows the relationship between the rotation position of a 1st, 2nd sensor flag member and the on-off signal of a 1st, 2nd position sensor. The block diagram which shows the control structure of the punching apparatus of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the accompanying drawings, similar components are denoted by similar reference numerals throughout the present specification.

  FIG. 1 schematically shows the overall configuration of an image forming system including a punching device according to the present invention. As shown in the figure, the image forming system is composed of an image forming apparatus A that sequentially prints sheets and carries them out, and a sheet post-processing apparatus B that is provided downstream of the image forming apparatus A. The sheet post-processing device B includes the punching device C of the present invention.

  The image forming apparatus A according to this embodiment is a copying machine that uses an electrostatic printing process, and includes an image forming unit A1, a scanner unit A2, and a feeder unit A3. The present invention can be applied to image forming apparatuses having various structures such as printers and printing machines.

  The image forming unit A1 includes a paper feed unit 2, an image forming unit 3, a paper discharge unit 4, and a control unit (not shown) inside the housing 1. The sheet feeding unit 2 is provided with a plurality of sheet cassettes 5, and the sheets of the size and orientation instructed by the control unit are fed to the sheet feeding path 6. The sheet fed to the paper feed path 6 is fed to the image forming unit 3 on the downstream side at a predetermined timing after aligning the leading end positions by the registration rollers 7.

  The image forming unit 3 attaches toner ink to the latent image formed on the electrostatic drum 10 by the head 9 formed of, for example, a laser light emitting device by the developing device 11 and transfers the image transferred onto the sheet by the transfer charger 12 to the fixing roller 13 Fix with. In the paper discharge unit 4, a paper discharge path 16 in which a paper discharge port 14 and a paper discharge roller 15 opening in the casing 1 are arranged, and a sheet fed in a switchback manner from the paper discharge path is turned upside down, and the registration roller is again turned. 7 and a circulation path 17 for forming an image on the back surface of the sheet. The sheet on which one side or both sides of the image are formed by the image forming unit 3 is conveyed to the sheet post-processing apparatus B from the sheet discharge port 14 by the sheet discharge roller 15.

  The scanner unit A2 includes a platen 21 on which a document sheet is placed, a carriage 22 that reciprocates along the platen to scan an image on the document sheet, and photoelectrically converts light reflected from the document on the platen 21 by the carriage. And an optical reading unit 23 for outputting to the image forming unit 3. A document sheet is automatically fed to the platen 21 from a feeder unit 25 arranged on the scanner unit A2.

  The sheet post-processing device B is arranged with the carry-in port 27 of the housing 26 aligned with the paper ejection port 14 in order to introduce the sheet from the paper ejection port 14 of the image forming apparatus A. The housing 26 is provided with a sheet carry-in path 28 for transporting a sheet from the carry-in entrance 27, and a sheet discharge stacker 29 for stacking sheets carried out from the sheet carry-in path.

  A punching device C is arranged in the sheet carrying-in path 28, and a carrying-in roller pair / sheet end aligning means 30 is provided on the upstream side thereof, and a forward / reverse transporting roller 31 pair is provided on the downstream side. A sheet detection sensor Si that detects the trailing end of the sheet carried into the sheet carry-in path 28 is provided between the punching device C of the sheet carrying path 28 and the carry-in roller 29.

  When the trailing edge of the sheet is detected by the sheet detection sensor Si, the control section reverses the conveyance roller pair 31 to switch back the sheet, and the trailing edge of the sheet hits the sheet edge aligning means 30 to align the sheet. Then, the transport roller pair 31 is stopped. The punching device C is operated to punch a punched hole at a predetermined position in the sheet in which the trailing ends of the sheet are aligned and positioned.

  FIG. 2 schematically shows the entire configuration of the punching device C. The punching device C of the present embodiment is provided with four punch members for automatically punching two holes or four holes in the sheet as described later. As a matter of course, the present invention can be similarly applied to a punching device having a structure including two, three, or five or more punch members.

  As shown in FIGS. 2 to 4, the punching device C includes four punch members 40, a device frame 41 for mounting and supporting the punch members 40, a common drive motor 42 for driving the punch members, and rotation of the drive motors. And a common rotary drive shaft 43 that is transmitted to the punch member. Further, the punching device C includes a control unit for controlling the rotation of the drive motor as described later.

  The device frame 41 includes an upper frame 44 and a lower frame 45 extending in parallel to the longitudinal direction, and a side frame 46 arranged on one side (left side in the drawing) of them. As shown in FIG. 6, the upper frame 44 includes a horizontal upper plate portion 48, an intermediate plate portion 49 extending vertically downward from one end of the upper plate portion, and a right angle from a lower end of the intermediate plate portion. It has an upper plate portion 48 and a lower plate portion 50 having a substantially L-shaped cross section and extending in parallel.

  The lower frame 45 has a horizontal and flat upper surface defining a sheet support surface 45a for supporting a sheet to be punched. The upper and lower frames 44, 45 are arranged so that a constant small gap 51 is defined between the horizontal lower surface of the lower plate portion 50 and the seat supporting surface 45a over substantially the entire length thereof. In addition, they are integrally connected at the left and right ends thereof. The gap 51 forms a sheet path for arranging the sheet carried into the sheet post-processing apparatus B from the image forming apparatus A at a predetermined punching position.

  In the upper frame 44, four punch members 40 (40a to 40d) are linearly arranged along the longitudinal direction thereof at predetermined intervals, for example, corresponding to the file hole intervals set by a predetermined standard. ing. As shown in FIG. 6, each punch member 40 is a circular rod-shaped member that extends in the vertical direction in the drawing and has a substantially constant diameter over the entire length, and has a cylindrical perforating blade 53 formed at the lower end thereof. . The piercing blade 53 cuts the cylindrical peripheral edge of the punch member 40 into a V-shape when viewed from the side surface direction, that is, defines a V-shaped notch at each of the opposed side surface positions of the cylindrical peripheral edge. Is formed in.

  Guide holes 44a and 44b are formed in the upper frame 44 at positions vertically opposed to the upper plate portion 48 and the lower plate portion 50, respectively. An upper end portion 40a of the punch member 40 is inserted into the upper guide hole 44a, and a lower end portion 40b thereof is inserted into the lower guide hole 44b so as to be rotatable and axially slidable. In the lower frame 45, a circular die hole 54 for punching a sheet with the punching blade 41 is provided at a position corresponding to the lower guide hole 44b of the upper frame 44.

  A cam member 56, which is a cylindrical cam concentric with the punch member 40, is integrally packaged in the circumferential direction and the axial direction. Further, in the punch member 40, a driven gear 57 composed of a screw gear is sandwiched above the cam member 56 with a partition plate 58 extending horizontally from the intermediate plate portion 49 of the upper frame 44 toward the punch member at a right angle. Thus, it is mounted so as to be integrally rotatable in the circumferential direction and relatively displaceable in the axial direction. The cam member 56 is axially movable integrally with the punch member 40 between the lower plate portion 50 and the partition plate 58. On the other hand, the driven gear 57 is held substantially displaceable in the axial direction between the upper plate portion 48 and the partition plate.

  The cam member 56 has an endless cam groove 60 (60a to 60d) formed on the outer peripheral surface thereof so as to be recessed over the entire circumference. On the intermediate plate portion 49, a cam pin 61 is horizontally projected toward the outer peripheral surface of the cam member 56. The cam pin 61 is arranged so that its tip is fitted into the cam groove 60 and is engaged with the upper and / or lower cam surface thereof.

  As shown in FIG. 6, the cam groove 60 has a linear portion 62 extending in the circumferential direction at a constant low height position, and a linear portion 62 rising from the linear portion to a vertex portion of a predetermined height at a substantially constant rate. And a sloped portion 63 that descends from the portion to the straight portion 62 at the same rate. The apex portion of the inclined portion 63 is preferably curved to some extent in order to avoid a sudden change in the cam groove 60.

  When the cam pin 61 is in the straight portion 62 of the cam groove 60, the punch member 40 is held at the top dead center position in the axial direction, as shown in FIG. The punch member 40 is arranged so that the tip of the punching blade 41 does not project into the gap 51 from the lower guide hole 44b at the top dead center position.

  When the cam member 56 rotates and the cam pin 61 enters the inclined portion 63 from the straight portion 62 of the cam groove 60, the punch member 40 descends axially downward from the top dead center position. When the cam pin 61 reaches the apex of the inclined portion 63, the punch member 40 reaches the bottom dead center position in the axial direction shown in FIG. 7B and completely penetrates the sheet S to form a punch hole. It The punch member 40 moves upward from the bottom dead center position in the axial direction when the cam member 56 further rotates and the cam pin 61 crosses the apex of the inclined portion 63. When the cam pin 61 enters the straight portion 62 from the inclined portion 63 of the cam groove 60, the punch member 40 reaches the top dead center position in FIG. 7A and stops moving in the axial direction.

  As shown in FIG. 4, the rotary drive shaft 43 extends on the rear side of the punch member 40 along the arrangement direction thereof, and pivots to the left and right end support portions 64a and 64b of the upper frame 44 near the left and right ends thereof. It is supported freely. Four drive gears 65, which are screw gears, are concentrically and integrally mounted on the rotary drive shaft 43 in the circumferential direction and the axial direction. Each drive gear 65 has its axial direction orthogonal to that of the driven gear 57 of each punch member 40 through a window 66 opened from the intermediate plate portion 49 of the upper frame 44 to the upper plate portion 48. It is arranged to mesh with the staggered shafts. In the present embodiment, the rotation direction of the rotary drive shaft 43 as viewed from the side frame 46 side and the rotation direction of the punch member 40 as viewed in plan are provided so as to coincide with each other.

  As shown in FIG. 3, the drive motor 42 is horizontally mounted on the side frame 46 so that its output shaft 67 faces the punch member 40 and is parallel to the rotary drive shaft 43. A drive gear 68 is attached to the tip of the output shaft 67. A driven gear 69 is attached to an end portion 43a of the rotary drive shaft 43 protruding from the support portion 64a of the upper frame 44 toward the drive motor 42 side. The drive gear 68 and the driven gear 69 are connected via an intermediate gear train 70 provided on the side frame 46, and the rotation of the drive motor 42 is decelerated and transmitted to the rotary drive shaft 43. In this embodiment, the rotation direction of the drive motor 42 and the rotation direction of the rotary drive shaft 43 are set to coincide with each other.

  An encoder 71 for detecting the rotation amount of the drive motor 42 is provided on the side frame 46 on the side opposite to the punch member 40. The encoder 71 of the present embodiment is an optical transmission type, and is opposed to a code wheel 72 mounted integrally rotatably at an end of the drive motor 42 on the opposite side of the output shaft 67, and to the side frame 46 with the code wheel interposed therebetween. The sensor unit 73 includes a light projecting unit and a light receiving unit arranged. Thereby, the rotation of the drive motor 42 can be controlled with higher accuracy.

  Further, the side frame 46 is provided with two position sensors 75 and 76 as a position detection mechanism for detecting the rotational position of the rotary drive shaft 43. The position sensors 75 and 76 of the present embodiment are transmissive photosensors having a light projecting section and a light receiving section that are opposed to each other with a predetermined gap. The position sensor is turned off when light passes from the light projecting unit to the light receiving unit, and is turned on when a sensor flag passes through the gap between the light projecting unit and the light receiving unit to block light. The light emitting / receiving positions of the light emitting unit and the light receiving unit of the first position sensor 75 are set to the reference position PR, and the rotation angle position of the rotary drive shaft 43 can be determined by setting the rotation angle to 0 °.

  Two sensor flag members 77, 78 are attached to the end 43a of the rotary drive shaft 43 on the drive motor 42 side so as to rotate integrally with the rotary drive shaft on the tip side of the driven gear 69. The first sensor flag member 77 on the more distal side passes through the gap between the light projecting portion and the light receiving portion of the first position sensor 75, and the second sensor flag member 78 projects the second position sensor 76. They are arranged so as to pass through the gap between the light portion and the light receiving portion.

  In the present embodiment, the first and second sensor flag members 77 and 78 are arranged close to each other in the axial direction of the rotary drive shaft 43 in order to reduce the size of the device. Therefore, the first and second position sensors 75 and 76 are arranged. As shown in FIG. 4, are attached while being displaced in the rotational direction of the rotary drive shaft 43. Further, the second sensor flag member 78 is formed such that its radius is slightly larger than that of the first sensor flag member 77.

  FIG. 8 is a development view of the cam grooves 60a to 60d of the punch members 40a to 40d. As shown in the figure, in the first punch member 40a at the left end in FIG. 3, the cam groove 60a has one linear portion 62a and one inclined portion 63a. The cam groove 60b of the second second punch member 40b from the left has two inclined portions 63b1 and 63b2 and two linear portions 62b1 and 62b2 connecting them. The cam groove 60c of the third third punch member 40c from the left has two inclined portions 63c1 and 63c2 and two linear portions 62c1 and 62c2 connecting them, like the second punch member 40b. . The cam groove 60d of the fourth punch member 40d at the right end has one linear portion 62d and one inclined portion 63d, like the first punch member 40a. The straight portions 62a to 62d of each cam groove are formed at the same height position, and the inclined portions 63a, 63b1, 63b2, 63c1, 63c2, 63d are formed in the same shape and size.

  In FIG. 8, the inclined portions 63a, 63b1, 63c1 and 63d of the first to fourth punch members 40a to 40d described on the left side portion are used to punch four holes in the sheet. The inclined portions 63b2 and 63c2 of the second and third punch members 40b and 40c shown in the right side portion of the figure are used to punch two holes in the sheet.

  The cam pins 61 that engage with the cam grooves 60a to 60d are all provided at the same angular position, while the apex positions of the inclined portions are arranged with a slight phase difference therebetween. The inclined portions 63a, 63b1, 63c1, 63d for punching four holes are arranged such that the respective vertex positions 63pa, 63pb1, 63pc1, 63pd are sequentially shifted in phase by a predetermined angle Δα along the circumferential direction. Similarly, the inclined portions 63b2 and 63c2 for punching two holes are arranged such that the vertex positions 63pb2 and 63pc2 are sequentially shifted in phase by a predetermined angle Δβ along the circumferential direction. The predetermined angle Δα and the predetermined angle Δβ may have the same value or different values.

  By providing the phase difference in this manner, punch holes of four holes or two holes are punched in the sheet with the timing slightly shifted. This makes it possible to reduce the load applied to the drive motor 42 of the punch members when punching a sheet simultaneously with the punch members 40.

  In FIG. 8, the cam grooves 60a to 60d are provided with two angular ranges in which the linear portions of all the punch members 40a to 40d overlap at the same time. In this embodiment, the two angular ranges are referred to as first and second home positions Hp1 and Hp2. At the first and second home positions, all punch members 40a to 40d are in a state of waiting for the next punching operation at the top dead center position. On the other hand, in the two angular ranges between the first and second home positions Hp1 and Hp2, at least one punch member 40 is performing the punching operation, and in the present embodiment, these are set to the first and second operating positions. Called Op1 and Op2.

  When the punch members 40a to 40d rotate clockwise from the first home position Hp1 in a plan view of the punch member, the cam pin 61 moves rightward in the drawing to enter the first operating position Op1 of the cam grooves 60a to 60d. A two-hole punching operation is performed. On the contrary, when the punch member rotates counterclockwise from the first home position Hp1, the cam pin 61 moves to the left side in the drawing to enter the second operation position Op2 of the cam groove, and a four-hole punching operation is performed. . When the punch members 40a to 40d rotate from the second home position Hp2, the rotation direction is opposite to the 2-hole / 4-hole punching operation.

  9A and 9B, the first and second sensor flag members 77, 78 and the first and second position sensors 75, 76 are shown in which the end portion 43a of the rotary drive shaft 43 is viewed from the drive motor 42 side. Shows the positional relationship with. As shown in FIG. 9A, the first sensor flag member 77 is formed of a fan-shaped shading plate having a wing shape with a constant width and extending outward in the radial direction about the axis of the rotary drive shaft 43. It has 1 and 2 flag parts 80 and 81.

  One rotation of the rotary drive shaft 43 is set so as to correspond to one rotation of the cam member 56, that is, the cam groove 60. The first and second flag portions 80 and 81 are set such that their angular ranges correspond to the angular ranges of the first and second operating positions Op1 and Op2 of FIG. 8, respectively. The fan-shaped first and second gap portions 82 and 83 defined between the first and second flag portions 80 and 81 have angular positions and angular ranges that are the same as those of the first and second home positions Hp1 and Hp2. It is set to correspond.

  As shown in FIG. 9B, the second sensor flag member 78 is also formed of a fan-shaped light-shielding plate having a wing shape with a constant width and extending outward in the radial direction around the axis of the rotary drive shaft 43. The third flag unit 85 is included. The third flag portion 85 is set such that its angular range corresponds to the continuous angular range of the adjacent second operating position Op2 and first home position Hp1 in FIG. Therefore, the void portion 86 of the second sensor flag member 78 without the light shielding plate corresponds to the continuous angular range of the first operating position Op1 and the second home position Hp2 in FIG. Further, the radius of the third flag portion 85 is formed to be slightly larger than that of the first and second flag portions 80 and 81.

  The first position sensor 75 detects the edge portions 80a and 80b of the first flag portion 80 and switches the output signal ON / OFF, and the first and second home positions Hp1 and Hp2 adjacent to the first operating position Op1. It is arranged with respect to the first sensor flag member 77 so that the timings at which the boundaries are crossed coincide with each other. Therefore, the first position sensor 75 detects the edge portions 81a and 81b of the second flag portion 81 and switches the on / off of the output signal, and the first and the second operation positions Op2 adjacent to the second flag portion 81. The timing of crossing the boundary between the two home positions Hp1 and Hp2 coincides.

  The second position sensor 76 detects the edge portion 85a of the third flag portion 85 and separates the boundary between the timing at which the output signal is switched from off to on and the second home position Hp2 adjacent to the second operation position Op2. It is arranged with respect to the second sensor flag member 78 so that the timing to cross it may coincide. Accordingly, the second position sensor 76 detects the other edge portion 85b of the third flag portion 85 and switches the output signal from ON to ON, and the boundary between the first operating position Op1 and the first home position Hp1. The timing of crossing is the same.

  FIG. 10 shows the relationship between the output signal of the position detection mechanism of the rotary drive shaft 43 set in this way and the home position and operating position set by the cam groove 60 of the punch member 40. As shown in the figure, when the punch member 40 is at the first home position Hp1, the first position sensor 75 is off, the second position sensor 76 is on, and when the punch member 40 is at the second home position Hp2, Both the first and second position sensors 75 and 76 are turned off. When the punch member 40 is in the first operating position Op1, the first position sensor 75 is on and the second position sensor 76 is off. When the punch member 40 is in the second operating position Op2, the first and second positions are the same. Both the position sensors 75 and 76 are turned on.

  By detecting the output signals of the first and second position sensors 75 and 76 in this way, it is possible to easily determine in which rotation angle range the rotation drive shaft 43 is within the one rotation range. Therefore, when the punch member 40 is stopped at the first home position Hp1 or the second home position Hp2, the drive motor 42 is rotated in the normal direction or the reverse direction from that position, so that the two holes or the four holes specified from the main body side are obtained. The punching operation of can be started.

  Further, when the punch member 40 is stopped at the first or second operating positions Op1 and Op2 due to an unexpected power interruption or the like, the position is immediately determined by turning on the power again. Therefore, by rotating the rotary drive shaft 43 in the forward or reverse direction by a maximum of 1/2, the punch member 40 can be returned to the first or second home position Hp1, Hp2, and the desired punching operation can be resumed. .

  FIG. 11 schematically shows the control configuration of the punching device C of the present embodiment. The punching device C includes a control unit 87 for controlling the punching operation of the sheet. The control unit 87 includes a CPU 88 that controls the drive voltage applied to the drive motor 42, and a memory 89 that stores information and data necessary for the punching process and its control. In another embodiment, the control unit 87 can be provided in a main body device such as an image forming device or a sheet post-processing device in which the punching device C is incorporated.

  The controller 87 is connected to the motor drive circuit 91 connected between the drive motor 42 and its power source 90, the encoder 71, and the first and second position sensors 75 and 76. Further, the main body control unit 92 provided in the main body device is connected to the control unit 87. The control unit 87 can obtain from the main body control unit 92 the information necessary for performing the punching process on the sheet conveyed from the main body apparatus.

  When the punching process ends normally, the punch member 40 stops at either the first home position Hp1 or the second home position Hp2. The control unit 87 can detect which home position the punch member 40 has stopped by the output signals from the first and second position sensors 75 and 76 at the end of the punching process. Therefore, when the control section 87 receives an instruction for the next punching process from the main body control section 92, it does not perform the punching operation of two holes or four holes without returning the punch member to the sole home position as in the above-described conventional technique. You can start.

  Further, when the punching process is not normally completed for some reason, the control unit 87 can also detect the stop position of the punch member 40 by the output signals from the first and second position sensors 75 and 76. it can. For example, when the punch member 40 is stopped at the first or second operating position Op1 or Op2, the control unit 87 rotates the rotary drive shaft 43 by a maximum of 1/2 to move the punch member 40 to the first home position Hp1 or the first home position Hp1. It is possible to return to the two-home position Hp2 and prepare for restarting the punching operation or the next punching process.

  In the above embodiment, the case where the punching device C includes four punching members and punches the sheet in two punching patterns of two holes or four holes has been described. The present invention can be similarly applied to a punching device capable of punching with three or more punching patterns. In that case, the same number of sensor flag members and position sensors as the number of drilling patterns are arranged on the rotary drive shaft 43, and one sensor flag member has a flag portion corresponding to the home position and the operating position formed in the cam groove 60. However, the other sensor flag members may be provided with one flag portion corresponding to a different operation position and a home position adjacent thereto.

  For example, when the punching device C has five punch members and executes three punching patterns of 2 holes / 3 holes / 4 holes, three sensor flag members are attached to the rotary drive shaft 43, and the corresponding three holes are used. Place two position sensors. One sensor flag member is formed with three flag positions corresponding to three operating positions corresponding to three drilling patterns and three home positions. The other two sensor flag members are provided with one flag portion corresponding to a different operating position and a home position adjacent thereto. Thus, the output signals from the three position sensors can similarly detect the rotational position of the rotary drive shaft 43 and the positional state of the punch member.

  Although the present invention has been described above with reference to the preferred embodiments, the present invention is not limited to the above embodiments, and various modifications or changes can be made within the technical scope thereof. Needless to say. For example, the first and second position sensors 75 and 76 are not limited to the transmissive photosensors described above, but may be any one that uses a detector that rotates integrally with the rotary drive shaft 43 like the sensor flag member. Various known sensors such as a reflective photo sensor, a magnetic sensor, and an ultrasonic sensor can be used.

A image forming device B sheet post-processing device C punching device 40, 40a to 40d punch member 41 device frame 42 drive motor 43 rotary drive shaft 53 punching blade 56 cam member 60 cam groove 61 cam pin 71 encoder 75, 76 position sensor 77, 78 Sensor flag member 80 First flag portion 81 Second flag portion 85 Third flag portion 87 Control portion

Claims (8)

A plurality of punch members that reciprocate between a punching position and a standby position to punch a sheet,
A drive motor capable of rotating in the forward and reverse directions for driving the plurality of punch members,
A rotary drive shaft that transmits the rotation of the drive motor to the plurality of punch members;
A plurality of sensor flag members that rotate integrally with the rotary drive shaft,
A plurality of position sensors that are provided in the same number as the plurality of sensor flag members and detect the corresponding sensor flag members , respectively.
A control unit for controlling the rotation of the drive motor,
Within one rotation of the rotary drive shaft, a plurality of operating positions in which at least one of the punch members is performing a punching operation, and the same number of home positions as the plurality of operating positions in which all of the punch members are in the standby position. And are provided alternately ,
One of the sensor flag members has a plurality of flag portions corresponding to the plurality of operating positions and the home position, and the plurality of flag portions are respectively provided at both ends in the rotation direction when the one sensor flag member is rotated. said detected by position sensor corresponding to the one sensor flag member has an edge portion off are provided to switch the output signal, and the edge portion of said plurality of flag unit, each of the Arranged to correspond to a boundary between a plurality of operating positions and the home position adjacent thereto,
The remaining sensor flag member has one flag portion corresponding to the one different operating position and the home position adjacent thereto, and the one flag portion has the remaining sensor at both ends in the rotation direction. When the flag member is rotated, the flag sensor has an edge portion which is detected by the position sensor corresponding to each of the remaining sensor flag members to switch ON / OFF of the output signal, and the edge portion of the one flag portion is Are arranged so as to correspond to the boundaries between the one operating position and the home position adjacent thereto, and the operating position and the home position adjacent to them.
The drilling system, wherein the control unit detects a rotational position of the rotary drive shaft based on output signals of the plurality of position sensors. One revolution of the rotary drive shaft alternately has two working positions and two home positions,
A plurality of sensor flag members having a first sensor flag member having two flag portions corresponding to the two actuation positions and the two home positions; and one of the two actuation positions and the two homes adjacent thereto. The drilling system according to claim 1, comprising a second sensor flag member having one flag portion corresponding to one of the positions.   The punch member reciprocates between the punching position and the standby position in the axial direction while rotating about the axis thereof to punch the sheet, and the punch member makes one rotation and the rotary drive shaft makes one rotation. 3. Corresponding to and, the drilling system according to claim 1 or 2.   The perforation system according to claim 1, wherein the position sensor is a transmissive photo sensor. A plurality of punch members that reciprocate between a punching position and a standby position to punch a sheet,
A drive motor capable of rotating in the forward and reverse directions for driving the plurality of punch members,
A rotary drive shaft that transmits the rotation of the drive motor to the plurality of punch members;
A plurality of sensor flag members that rotate integrally with the rotary drive shaft,
The same number as the plurality of sensor flag members is provided, and a plurality of position sensors for detecting the corresponding sensor flag members are provided,
Within one rotation of the rotary drive shaft, a plurality of operating positions in which at least one of the punch members is performing a punching operation, and the same number of home positions as the plurality of operating positions in which all of the punch members are in the standby position. And are provided alternately ,
One of the sensor flag members has a plurality of flag portions corresponding to the plurality of operating positions and the home position, and the plurality of flag portions are respectively provided at both ends in the rotation direction when the one sensor flag member is rotated. said detected by position sensor corresponding to the one sensor flag member has an edge portion off are provided to switch the output signal, and the edge portion of said plurality of flag unit, each of the Arranged to correspond to a boundary between a plurality of operating positions and the home position adjacent thereto,
The remaining sensor flag member has one flag portion corresponding to the one different operating position and the home position adjacent thereto, and the one flag portion has the remaining sensor at both ends in the rotation direction. When the flag member rotates, the position sensor corresponding to each of the remaining sensor flag members has an edge portion for switching on / off of the output signal, and the edge portion of the one flag portion is the In one of the operating positions and the home position adjacent thereto, and a drilling system arranged so as to correspond to a boundary between the operating position and the home position adjacent to them,
A drilling system control method, comprising: determining a rotational position of the rotary drive shaft based on output signals of the plurality of position sensors.   When it is determined from the output signals of the plurality of position sensors that the punch member is stopped at the operating position, the drive is performed to move the punch member to the home position adjacent to the operating position. The method according to claim 5, further comprising controlling a 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 7.

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