JP2017154192A - Punching system, control method thereof, sheet processing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a punching system and a control method capable of easily detecting a rotation position of a rotation driving shaft by using one flag member and one position sensor which are attached to the rotation driving shaft.SOLUTION: A punching device C comprises: a plurality of punching members 40; a drive motor 42 that drives the punching members; a rotation driving shaft 43 that transfers rotations of the drive motor to the punching members; and a control part 87 that controls the drive motor. The rotation driving shaft, during one rotation, has first and second operation positions where at least one punching member performs punching operation and first and second home positions where all the punching members are in a stand-by state, alternately. The control part determines a rotation position of the rotation driving shaft by detecting an edge of a flag part of a sensor flag member 77 fixed to the rotation driving shaft with use of a position sensor 75.SELECTED DRAWING: Figure 9

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. For example, there is known a perforating apparatus that perforates a plurality of punch holes in a sheet by reciprocating a plurality of punch members in a perforating direction with a drive motor (see, for example, Patent Documents 1 and 2).

  The perforating apparatus described in Patent Documents 1 and 2 includes a drive rotation shaft that transmits forward and reverse rotations of a drive motor to a plurality of punch members, and the rotation of each drive member is rotated by a gear mechanism and a cam mechanism. And it converts into the linear reciprocating motion of an axial direction, and the punching operation | movement of a several punch hole is performed. The number of punch holes formed in one sheet is controlled by controlling the rotation direction and rotation range of the drive rotation shaft, thereby switching the group of punch members that perform the punching operation, and selecting 2 holes or 4 holes (or 3 holes). You can choose.

  In the punching device of Patent Document 2, when the rotation position of the drive rotary shaft in which the punch member is at the top dead center standby position is set as the reference position and the drive motor is rotated forward from the reference position, the punch member of the first group is punched. When operated and reversed, the second group of punch members are perforated. The rotation direction of the drive motor is controlled based on on / off signals from first and second flag sensors that detect the positions of the first and second flags that rotate together with the drive rotation shaft.

  Further, the home position sensor detects the notch of the home position filler mounted on the shaft of the crank gear that is rotated by the DC brush motor that is the driving source for drilling, so that the punch blade does not protrude into the gap from the lower frame. A paper punching device that detects a home position is known (see, for example, Patent Document 3). Two notches of the home position filler are provided at positions that face each other by 180 °.

JP 2012-228770 A JP 2013-116535 A JP 2004-345834 A

  When the main body of the image forming apparatus or sheet processing apparatus equipped with the punching device or the punching device itself is turned off for some reason and then turned on again, the punching member of the punching device often restarts the punching operation. Before, it is returned to the top dead center standby position. When the punching device is normally completed, as described in Patent Document 2, for example, the drive rotation shaft is controlled to be positioned at the reference position during the initialization operation of the punching device.

  In order to return the punch member to the standby position, it is necessary to know the rotational position of the drive rotary shaft. If a plurality of flag sensors and flags are used as in the conventional devices described in Patent Documents 1 and 2, it is not always possible to detect the rotational position of the drive rotary shaft in any group of punching operations. Not difficult. However, as the number of flag sensors and flags increases, the size of the drilling device increases and the cost increases.

  As described in Patent Document 3, when two home positions are provided at a position opposite to one home position filler by 180 °, it is not easy to identify the home position with one home position sensor. Therefore, as described in Patent Documents 1 and 2, in the case of a punching device in which the number of punch holes is switched depending on the rotation direction and rotation range of the drive rotary shaft, the drilling process is interrupted when starting the next drilling operation or interrupted. When resuming, there is a possibility that the direction in which the drive rotation shaft should be rotated cannot be determined.

Therefore, the present invention has been made in view of the above-described problems of the prior art, and the object thereof is, in particular, perforation in which the number of punch holes perforated in a sheet is switched depending on the rotation direction and rotation range of the drive rotation shaft. It is an object of the present invention to provide a drilling system that can easily detect the rotational position of a drive rotary shaft using one flag member attached to the drive rotary shaft and one position sensor, and a control method therefor.
Another object of the present invention is to provide a sheet processing apparatus and an image forming apparatus provided with such a perforation system.

In order to achieve the above object, the drilling system of the present invention provides
A plurality of punch members that reciprocate between the punching position and the standby position to punch the sheet;
A drive motor capable of rotating forward and reverse to drive a plurality of punch members;
A rotation drive shaft that transmits rotation of the drive motor to the plurality of punch members;
One sensor flag member that rotates integrally with the rotary drive shaft;
One position sensor for detecting the sensor flag member;
An encoder that detects the amount of rotation of the drive motor;
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 punch member is perforated, and a plurality of operating positions in which all punch members are in the standby position and the same number of home positions are alternately provided. And
The sensor flag member has a plurality of flag portions corresponding to the plurality of operating positions and home positions,
The control unit detects the rotational position of the rotary drive shaft based on the rotation amount of the drive motor detected by the encoder while the position sensor detects the passage of any one of the flag units.

  According to the present invention, the control unit can detect the rotational position of the rotary drive shaft by using one sensor flag member, one position sensor, and an encoder in this way, and thus starts or resumes next. The direction in which the rotary drive shaft should be rotated can be easily determined in accordance with the drilling operation, and the entire apparatus can be reduced in size and cost.

  In one embodiment, two operation positions and two home positions are alternately provided in one rotation of the rotary drive shaft, and the sensor flag member is associated with the two operation positions and the two home positions. It has two flag parts provided. Since the number of operating positions and home positions is two, the determination of the rotational position of the rotary drive shaft and the control of the drive motor become easier and more reliable.

  In another embodiment, the punch member rotates about its axis and reciprocates between the punching position and the standby position in the axial direction to punch the sheet, and the punch member and the rotation drive shaft rotate once. Corresponds. Thereby, the relationship between the operation of the punch member and the rotation of the rotary drive shaft can be grasped and controlled more clearly.

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

Moreover, the drilling system control method of the present invention includes:
A plurality of punch members that reciprocate between the punching position and the standby position to punch the sheet;
A drive motor capable of rotating forward and reverse to drive a plurality of punch members;
A rotation drive shaft that transmits the rotation of the drive motor to a plurality of punch members;
One sensor flag member that rotates integrally with the rotary drive shaft;
One position sensor for detecting the sensor flag member;
With an encoder that detects the amount of rotation of the drive motor,
Within one rotation of the rotary drive shaft, a plurality of operating positions in which at least one punch member is perforated, and a plurality of operating positions in which all punch members are in the standby position and the same number of home positions are alternately provided. And
In the drilling system, wherein the sensor flag member has a plurality of flag portions corresponding to the plurality of operation positions and the home position,
While the position sensor detects the passage of at least one of the flag portions, the rotational position of the rotational drive shaft is determined based on the rotational amount of the drive motor detected by the encoder.

  According to the present invention, the rotational position of the rotary drive shaft can be determined by using one sensor flag member, one position sensor and an encoder as described above, so that it corresponds to the drilling operation to be started or restarted next. Thus, the direction in which the rotary drive shaft should be rotated can be easily determined, and the entire apparatus can be reduced in size and cost.

  In one embodiment, the drive motor is controlled to move the rotary drive shaft to a predetermined home position based on the determined rotational position of the rotary drive shaft. As a result, the next drilling process can be started in a shorter time and more reliably.

  According to another aspect of the present invention, the above-described drilling system of the present invention is provided, whereby the detection of the rotational position of the rotary drive shaft in preparation for the start or restart of the drilling process is performed using one sensor flag member and one sensor Provided is a sheet processing apparatus that can be performed using a position sensor and an encoder, and that can realize downsizing and cost reduction of the apparatus.

  According to still another aspect of the present invention, the above-described punching system of the present invention or the sheet processing apparatus of the present invention described above is provided, thereby detecting the rotational position of the rotary drive shaft in preparation for the start or restart of the punching process. Can be performed using one sensor flag member, one position sensor, and an encoder, and an image forming apparatus that can realize downsizing and cost reduction of the apparatus is provided.

1 is an overall configuration diagram of an image forming apparatus and a sheet post-processing apparatus to which the present invention is applied. 1 is a perspective view of a drilling device according to the present invention. FIG. 3 is a front view of the punching device of FIG. 2. FIG. 3 is a plan view of the punching device of FIG. 2. The side view which shows the drive mechanism of the piercing | piercing apparatus of FIG. The expanded sectional view in the VI-VI line of FIG. (A), (b) figure is explanatory drawing of punching operation | movement of a punch member. The expanded view of the cylindrical cam of each punch member. Explanatory drawing which shows the positional relationship of a sensor flag member and a position sensor. The diagram which shows the relationship between the rotation position of a sensor flag member, the ON / OFF signal of a position sensor, and the operation state of a punch member along the rotation direction of a rotational drive shaft. 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 the accompanying drawings, similar components are denoted by the same reference numerals throughout the present specification.

  FIG. 1 schematically shows the overall configuration of an image forming system provided with a punching device according to the present invention. As shown in the figure, the image forming system includes an image forming apparatus A that sequentially prints and discharges sheets, and a sheet post-processing apparatus B that is provided on the downstream side in the sheet discharging direction. The sheet post-processing apparatus B incorporates a punching apparatus C of the present invention.

  The image forming apparatus A according to the present embodiment is a copying machine using 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 a printer and a printing machine.

  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 sheet having the size and direction designated by the control unit is fed out to the sheet feeding path 6. The sheet fed to the sheet feeding path 6 is fed to the downstream image forming unit 3 at a predetermined timing after the leading edge position is aligned by the registration roller 7.

  For example, the image forming unit 3 attaches toner ink to the latent image formed on the electrostatic drum 10 by the head 9 composed of a laser light emitter by the developing unit 11 and transfers the image transferred onto the sheet by the transfer charger 12 to the fixing roller 13. To fix. In the paper discharge unit 4, a paper discharge path 16 in which a paper discharge port 14 and a paper discharge roller 15 that are opened in the casing 1 are arranged, and a sheet fed back in a switchback manner from the paper discharge path are reversed, and the registration roller is again turned on. A circulation path 17 for forming an image on the back side of the sheet by feeding to 7- is arranged in parallel. The sheet on which the image forming unit 3 forms an image on one side or both sides is carried out from the sheet discharge port 14 to the sheet post-processing apparatus B by the sheet discharge roller 15.

  The scanner unit A2 photoelectrically converts a platen 21 on which a document sheet is placed, a carriage 22 that reciprocates along the platen to scan an image of the document sheet, and reflected light 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 disposed on the scanner unit A2.

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

  The sheet carry-in path 28 is provided with a punching device C, and is provided with a pair of carry-in rollers / sheet end aligning means 30 on the upstream side and a pair of conveyance rollers 31 capable of forward and reverse rotation on the downstream side. Between the punching device C and the carry-in roller 29 in the sheet conveyance path 28, a sheet detection sensor Si that detects the rear end of the sheet carried into the sheet carry-in path 28 is provided.

  When the trailing edge of the sheet is detected by the sheet detection sensor Si, the control unit reverses the conveying roller pair 31 to switch back the sheet, and the trailing edge of the sheet abuts against the sheet edge aligning unit 30 for alignment. Then, the conveyance roller pair 31 is stopped. In this way, punching holes are punched at predetermined positions by operating the punching device C on the sheet in which the rear end of the sheet is aligned and positioned.

  FIG. 2 schematically shows the entire configuration of the punching device C. As will be described later, the punching device C of this embodiment includes four punch members in order to automatically punch two or four holes in the sheet. Of course, the present invention can be similarly applied to a punching device having a structure including two, three, 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 motor. And a common rotational drive shaft 43 that is transmitted to the punch member. Furthermore, the perforation apparatus C includes a control unit for controlling the rotation of the drive motor, as will be described later.

  The apparatus frame 41 includes an upper frame 44 and a lower frame 45 extending in parallel with the longitudinal direction, and a side frame 46 disposed on one of the side portions (left side in the drawing). 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 portion of the upper plate portion, and a right angle from the lower end of the intermediate plate portion. The upper plate portion 48 and the lower plate portion 50 having a substantially L-shaped cross section extending in parallel with the upper plate portion 48 are included.

  The lower frame 45 defines a sheet support surface 45a for supporting a sheet to be punched by its horizontal and flat upper surface. The upper and lower frames 44 and 45 are arranged so that a slight gap 51 is defined between the horizontal lower surface of the lower plate portion 50 and the seat support surface 45a over substantially the entire length thereof. And they are integrally joined at their left and right ends. The gap 51 forms a sheet path for placing a sheet carried from the image forming apparatus A into the sheet post-processing apparatus B at a predetermined punching position.

  In the upper frame 44, four punch members 40 (40a to 40d) are arranged in a straight line along the longitudinal direction at a predetermined interval, for example, corresponding to the interval of the file holes set by a predetermined standard. ing. As shown in FIG. 6, each punch member 40 is formed of a circular rod-shaped member extending in the vertical direction in the drawing and having a substantially constant diameter over the entire length, and has a cylindrical perforated blade 53 formed at the lower end thereof. . The perforation blade 53 is formed so as to cut out the cylindrical peripheral edge of the punch member 40 in a V shape when viewed from the side, that is, to define a V-shaped cutout at a certain facing side surface position of the cylindrical peripheral edge. Is formed.

  In the upper frame 44, guide holes 44a and 44b are formed so as to penetrate the upper plate portion 48 and the lower plate portion 50, respectively, at positions facing each other in the vertical direction. 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 slidable in the axial direction. In the lower frame 45, a circular die hole 54 for punching a sheet by the punching blade 41 is provided at a position corresponding to the lower guide hole 44 b of the upper frame 44.

  A cam member 56 formed of a cylindrical cam concentric with the punch member 40 is integrally covered in the circumferential direction and the axial direction. Further, the punch member 40 has a driven gear 57 made of a screw gear sandwiching a partition plate 58 extending horizontally toward the punch member at a right angle from the intermediate plate portion 49 of the upper frame 44 on the upper side of the cam member 56. Thus, it is externally mounted so as to be rotatable in the circumferential direction and relatively displaceable in the axial direction. The cam member 56 is movable in the axial direction 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 undisplaceable 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) that is recessed over the entire outer periphery thereof. A cam pin 61 projects horizontally from the intermediate plate portion 49 toward the outer peripheral surface of the cam member 56. The cam pin 61 is disposed so that its tip end is fitted in the cam groove 60 and engages with the upper and / or lower cam surface.

  As shown in FIG. 6, the cam groove 60 has a straight portion 62 extending in the circumferential direction at a certain low height position, and rises from the straight portion to a vertex portion of a predetermined height at a substantially constant rate. A cam profile comprising an inclined portion 63 descending from the portion to the straight portion 62 at the same rate. In order to avoid a sudden change of the cam groove 60, the apex portion of the inclined portion 63 is preferably somewhat curved.

  When the cam pin 61 is in the linear 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 disposed so that the tip of the punching blade 41 does not protrude 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 downward in the axial direction from the top dead center position. When the cam pin 61 reaches the apex portion 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. The When the cam member 56 further rotates and the cam pin 61 exceeds the apex portion of the inclined portion 63, the punch member 40 moves upward in the axial direction from the bottom dead center position. When the cam pin 61 enters the linear 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 along the arrangement direction immediately behind the punch members 40, and rotates to the left and right end support portions 64a and 64b of the upper frame 44 in the vicinity of the left and right ends. It is supported freely. Four drive gears 65 made of screw gears are concentrically mounted on the rotary drive shaft 43 and integrally in the circumferential direction and the axial direction. Each drive gear 65 has the axial direction orthogonal to the driven gear 57 of each punch member 40 through a window 66 that extends from the intermediate plate portion 49 to the upper plate portion 48 of the upper frame 44. It arrange | positions so that it may mesh | engage with a misalignment axis | shaft. In the present embodiment, the rotation direction of the rotary drive shaft 43 as viewed from the side frame 46 side is provided so that the rotation direction of the punch member 40 in plan view coincides.

  As shown in FIG. 3, the drive motor 42 is mounted horizontally 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 driving gear 68 is attached to the tip of the output shaft 67. A driven gear 69 is attached to an end 43a of the rotary drive shaft 43 that protrudes from the support portion 64a of the upper frame 44 to 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 the present embodiment, the rotation direction of the drive motor 42 and the rotation direction of the rotation drive shaft 43 are set to coincide.

  The side frame 46 is provided with an encoder 71 for detecting the amount of rotation of the drive motor 42 on the side opposite to the punch member 40. The encoder 71 of the present embodiment is an optically transmissive type, and is opposed to a code wheel 72 that is rotatably attached to the opposite end of the output shaft 67 of the drive motor 42 and the side frame 46 with the code wheel interposed therebetween. And a sensor unit 73 including a light projecting unit and a light receiving unit. Thereby, the rotation of the drive motor 42 can be controlled with higher accuracy.

  Further, the side frame 46 is provided with a position sensor 75 as a position detection mechanism for detecting the rotational position of the rotation drive shaft 43. The position sensor 75 of the present embodiment is a transmissive photosensor having a light projecting portion and a light receiving portion arranged to face 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 turned on when a sensor flag passes through the gap between the light projecting unit and the light receiving unit and is blocked.

  A sensor flag member 77 is attached to an end portion 43a of the rotational drive shaft 43 on the drive motor 42 side so as to rotate integrally with the rotational drive shaft on the tip side of the driven gear 69. The sensor flag member 77 is disposed so as to pass through the gap between the light projecting unit and the light receiving unit of the position sensor 75. The position sensor 75 can determine the rotational angle position of the rotational drive shaft 43 by setting the light projecting / receiving position of the light projecting unit and the light receiving unit as a reference position PR and setting this as the rotational angle of 0 °.

  FIG. 8 is a development view of the cam grooves 60a to 60d of the punch members 40a to 40d. As shown in FIG. 3, 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 punch member 40b that is the second from the left has two inclined portions 63b1 and 63b2 and two linear portions 62b1 and 62b2 that connect them. Similar to the second punch member 40b, the cam groove 60c of the third punch member 40c third from the left has two inclined portions 63c1 and 63c2 and two linear portions 62c1 and 62c2 connecting them. . 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 the respective cam grooves are formed at the same height position, and the inclined portions 63a, 63b1, 63b2, 63c1, 63c2, and 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 in the left part are used for punching four holes in the sheet. The inclined portions 63b2 and 63c2 of the second and third punch members 40b and 40c described in the right part of the figure are used for punching 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, whereas the apex positions of the inclined portions are arranged with a slight phase difference. The inclined portions 63a, 63b1, 63c1, and 63d for drilling the four holes are arranged such that the vertex positions 63pa, 63pb1, 63pc1, and 63pd are sequentially shifted in phase by a predetermined angle Δα along the circumferential direction. Similarly, in the inclined portions 63b2 and 63c2 for drilling two holes, 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 be the same or different values.

  By providing the phase difference in this manner, four or two punch holes are formed in the sheet with the timing slightly shifted. Thereby, when simultaneously punching a sheet with a plurality of punch members 40, the load applied to the drive motor 42 of the punch members can be reduced.

  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 the present embodiment, the two angular ranges are referred to as first and second home positions Hp1 and Hp2. The first and second home positions are a state where all punch members 40a to 40d are waiting for the next punching operation at the top dead center position, that is, a standby position. On the other hand, the two angular ranges between the first and second home positions Hp1 and Hp2 are states in which at least one punch member 40 is performing a punching operation. In the present embodiment, these are the first and second home positions Hp1 and Hp2. These are referred to as two operation positions Op1, Op2.

  When the punch members 40a to 40d rotate in the clockwise direction from the first home position Hp1 in a plan view, the cam pin 61 moves to the right side in the drawing and enters the first operation position Op1 of the cam grooves 60a to 60d. A two-hole drilling operation is performed. Conversely, when the punch member rotates counterclockwise from the first home position Hp1, the cam pin 61 moves to the left side in the drawing and enters the second operation position Op2 of the cam groove, and a four-hole drilling operation is performed. . When the punch members 40a to 40d rotate from the second home position Hp2, the rotation direction and the drilling operation of 2 holes / 4 holes are reversed.

  FIG. 9 shows the positional relationship between the sensor flag member 77 and the position sensor 75 when the end 43a of the rotation drive shaft 43 is viewed from the drive motor 42 side. As shown in the figure, the sensor flag member 77 includes first and second flag portions formed of a fan-shaped light shielding plate having a fixed width extending outward in the radial direction around the axis of the rotation drive shaft 43. 80, 81. The first and second flag units 80 and 81 are provided so that their rotation angle ranges are different. In the present embodiment, the rotation angle range of the second flag unit 81 is larger than that of the first flag unit 80. The fan-shaped first and second gap portions 82 and 83 defined between the first and second flag portions 80 and 81 may have the same or different rotation angle ranges.

  One rotation of the rotation drive shaft 43 is set 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 provided such that their rotation angle ranges and positions correspond to those of the first and second operation positions Op1 and Op2 in FIG. The first and second gap portions 82 and 83 are also provided such that their rotational angle positions and ranges correspond to those of the first and second home positions Hp1 and Hp2. This means that the first and second operation positions Op1 and Op2 and the first and second home positions Hp1 and Hp2 are alternately provided within one rotation of the rotation drive shaft 43.

  The position sensor 75 detects the edge portions 80a and 80b of the first flag portion 80 relative to the sensor flag member 77, and the timing at which the output signal is turned on and off, and the first and first positions adjacent to the first operating position Op1. The two home positions Hp1 and Hp2 are arranged so as to coincide with the timing exceeding the boundary. As a result, the second flag portion 81 also has its edge portions 81a and 81b detected by the position sensor 75 and the timing at which the output signal is switched on and off, and the first and second home positions adjacent to the second operation position Op2. The timing of crossing the boundary between Hp1 and Hp2 is the same.

  FIG. 10 shows the relationship between the output signal of the position sensor 75 and the operating state of the punch member 40 set by the cam groove 60, that is, the home position and the operating position. As shown in the figure, the position sensor 75 is turned off when the punch member 40 is at the first or second home position Hp1, Hp2, and the punch member 40 is at the first or second operating position Op1, Op2. When turned on.

  As described above, since the rotation angle ranges of the first and second flag units 80 and 81 are different, the output pulse of the encoder 71 detected while the output of the position sensor 75 is turned on from off and turned off. By counting, it is possible to determine which of the first or second flag units 80 and 81 has passed through the position sensor 75. As a result, the positions of the first and second gap portions 82 and 83 can be determined based on the positional relationship with the first or second flag portions 80 and 81 that have just passed through the position sensor. In other words, the positions of the first and second home positions Hp1, Hp2 in one rotation of the rotation drive shaft 43 can be determined.

  Thereby, when the punching process is normally completed and all the punch members 40 return to the standby position, it is possible to determine the first home position Hp1 or the second home position Hp2. Therefore, the next 2-hole or 4-hole drilling operation can be started by rotating the drive motor 42 forward or backward as it is from the position of the home position where the punch member 40 is stopped.

  In addition, the first or second home position Hp1, Hp2 is selected from the determination result of the flag section that has just passed through the position sensor 75 and the rotation direction of the rotary drive shaft 43, and is matched with the reference position PR. The rotation drive shaft 43 can be stopped. Further, the position sensor 75 detects the edge portion on the rear end side of the flag portion that has just passed, and from the time when the position sensor 75 switches from on to off, the output pulse of the encoder 71 is counted to rotate the rotary drive shaft 43. By detecting the amount, the rotational drive shaft 43 can be stopped more accurately in accordance with the reference position PR.

  Further, when the punching process does not end normally due to unexpected power interruption during operation and the punch member 40 is stopped at the first or second operation position Op1, Op2, the drive motor 42 is driven after the power is turned on again. The rotational position of the rotational drive shaft 43 is determined in the same manner by rotating the rotational drive shaft 43 at a maximum of nearly one revolution and allowing any one of the flag portions to completely pass through the position sensor 75. Accordingly, the first and second home positions Hp1, Hp2 are discriminated, and the rotary drive shaft 43 is moved to one of them to return the punch member 40 to the standby position so that the punching operation can be resumed. be able to.

  FIG. 11 schematically shows a 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 apparatus or a sheet post-processing apparatus incorporating the punching device C.

  The controller 87 is connected to a motor drive circuit 91, an encoder 71, and a position sensor 75 connected between the drive motor 42 and its power supply 90. Further, a main body control unit 92 provided in the main body device is connected to the control unit 87. The control unit 87 can obtain information necessary for perforating the sheet conveyed from the main body apparatus from the main body control unit 92.

  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 determines which of the rotary drive shafts 43 is in accordance with the number of output pulses of the encoder 71 counted until the output signal from the position sensor 75 switches from off to on and switches off again immediately before the end of the punching process. Can detect whether stopped at home position. Accordingly, when the control unit 87 receives an instruction for the next drilling process from the main body control unit 92, the control unit 87 immediately returns to the next 2-hole or 4-hole without returning the punch member to the only home position as in the conventional technique described above. The drilling operation can be started.

  When the punching process does not end normally for some reason, the control unit 87 drives the drive motor 42 immediately after the power is turned on again so that one of the flag units completely passes through the position sensor 75. In addition, the rotation drive shaft 43 is rotated at a maximum of nearly one rotation. At this time, the rotational position of the rotary drive shaft 43 is similarly determined based on the number of output pulses of the encoder 71 counted from when the output signal from the position sensor 75 is switched from OFF to ON and then switched again. Therefore, the control unit 87 discriminates the first and second home positions Hp1, Hp2, moves the rotary drive shaft 43 to one of them, returns the punch member 40 to the standby position, and resumes the punching operation. It can be made possible.

  In the above embodiment, the case where the punching device C includes four punch members and punches a sheet with two punching patterns of two holes or four holes has been described. The present invention can be similarly applied to a drilling apparatus capable of drilling with three or more drilling patterns. In that case, one sensor flag member is fixed to the rotation drive shaft 43 and one corresponding position sensor is arranged, and the sensor flag member corresponds to the home position and the operating position formed in the cam groove 60. A plurality of flag portions are provided. At this time, the rotation angle range of at least one flag unit is set different from the rotation angle range of the other flag units. Accordingly, the rotational position of the rotary drive shaft is similarly determined from the number of output pulses of the encoder 71 counted when the position sensor completely detects the at least one flag portion and the rotational direction of the rotary drive shaft 43. can do.

  For example, when the punching device C includes five punch members and executes three punching patterns of 2 holes / 3 holes / 4 holes, the sensor flag member mounted on the rotation drive shaft 43 has three punching patterns. Three flag portions are formed in correspondence with the three operating positions and the home position corresponding to. At this time, by making the rotation angle range of at least one flag portion different from other flag portions, the rotation position of the rotary drive shaft 43 and the punch member are similarly detected by the output signal from the position sensor that detects the sensor flag member. The operating state can be detected.

  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, the position sensor 75 is not limited to the above-described transmission type photosensor, and may be a reflection type photosensor, as long as it uses a detector that rotates integrally with the rotation drive shaft 43, such as the sensor flag member. Various known sensors such as a magnetic sensor and an ultrasonic sensor can be used.

A Image forming apparatus B Sheet post-processing apparatus C Punching device 40, 40a to 40d Punch member 41 Device frame 42 Drive motor 43 Rotation drive shaft 53 Punching blade 56 Cam member 60 Cam groove 61 Cam pin 71 Encoder 75 Position sensor 77 Sensor flag member 80 1st flag part 81 2nd flag part 87 Control part

Claims (8)

A plurality of punch members that reciprocate between the punching position and the standby position to punch the sheet;
A drive motor capable of rotating forward and reverse to drive the plurality of punch members;
A rotation drive shaft for transmitting rotation of the drive motor to the plurality of punch members;
One sensor flag member that rotates integrally with the rotation drive shaft;
One position sensor for detecting the sensor flag member;
An encoder for detecting the rotation amount of the drive motor;
A controller for controlling the rotation of the drive motor,
A plurality of operating positions in which at least one punch member is perforated within one rotation of the rotational drive shaft, and the same number of home positions as the plurality of operating positions in which all the punch members are in the standby position Are provided alternately,
The sensor flag member has a plurality of flag portions corresponding to the plurality of operating positions and the home position,
The control unit detects a rotation position of the rotary drive shaft based on a rotation amount of the drive motor detected by the encoder while the position sensor detects the passage of any one of the flag units. Perforation system characterized by. Within one rotation of the rotary drive shaft, the two operating positions and the two home positions are alternately provided,
2. The drilling system according to claim 1, wherein the sensor flag member has two flag portions provided to correspond to the two operation positions and the two home positions.   The punch member rotates about the axis thereof and reciprocates between the punching position and the standby position in the axial direction to punch the sheet, and makes one rotation of the punch member and one rotation of the rotary drive shaft. The perforation system according to claim 1 or 2, wherein   The perforation system according to any one of claims 1 to 3, wherein the position sensor is a transmissive photosensor. A plurality of punch members that reciprocate between the punching position and the standby position to punch the sheet;
A drive motor capable of rotating forward and reverse to drive the plurality of punch members;
A rotation drive shaft for transmitting rotation of the drive motor to the plurality of punch members;
One sensor flag member that rotates integrally with the rotation drive shaft;
One position sensor for detecting the sensor flag member;
An encoder that detects the amount of rotation of the drive motor;
A plurality of operating positions in which at least one punch member is perforated within one rotation of the rotational drive shaft, and the same number of home positions as the plurality of operating positions in which all the punch members are in the standby position Are provided alternately,
In the drilling system, the sensor flag member has a plurality of flag portions corresponding to the plurality of operating positions and the home position,
While the position sensor detects the passage of at least one of the flag units, the rotational position of the rotational drive shaft is determined based on the rotational amount of the drive motor detected by the encoder. A drilling system control method.   6. The drilling system control method according to claim 5, wherein the drive motor is controlled to move the rotary drive shaft to a predetermined home position based on the determined rotational position of the rotary drive shaft. .   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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