Perforation device and sheet post-processing device equipped therewith

Abstract

To provide a punching device which can switch a punching pattern to a sheet with a compact configuration and reduce the switching time, and a sheet post-processing apparatus having the same.SOLUTION: A punching device 1 includes a shaft 12, a punching motor 11, a first punching part 15a and a second punching part 15b, a first cam 14a, a second cam 14b, a control part and a punching switching mechanism 90. The punching switching mechanism 90 moves the shaft 12 in a reciprocal manner in the axial direction to be selectively arranged at the first position where the first cam 14a is opposed to the first punching part 15a and the second punching part 15b and at the second position where the second cam 14b is opposed to the first punching part 15a. The control part can selectively execute the first punching processing and the second punching processing performed by arranging the shaft 12 at the first position and the second position.SELECTED DRAWING: Figure 4

Description

Technical Field

[0005] ,

[0004] , , ,

[0001] The present invention relates to a punching device that performs punching on a sheet and a sheet post-processing device including the same.

Background Art

[0002] Conventionally, a sheet post-processing device (finisher) attached to an image forming apparatus and performing predetermined post-processing on a sheet (paper) on which an image has been formed has been widely used. Some sheet post-processing devices include a punching device that performs punching (punch hole forming processing) on a sheet. <00000十一><00000十二>The punching device includes a punching blade for punching a sheet, and a punching process is performed on the sheet by the protruding punching blade hitting the sheet. The protruding punching blade is returned to a retracted position (home position) so as not to interfere with the punching process for the next sheet. When performing punching using a motor, a configuration is known in which the punching device includes a rotating member that rotates by the driving force of the motor and reciprocates the punching blade.

[0004] [[ID=十九]] In such a punching device, in order to change the number of punches, conventionally, units for two holes and four holes were mounted. However, there was a problem in that the configuration became complicated and the number of parts increased.<00000十六><00000十七><00000十八>Therefore, a technique for switching the number of punches has been proposed. For example, in Patent Document 1, there is a punch pin having a first rack gear and forming a hole in a sheet by moving in the axial direction, a slider having a second rack gear and reciprocating in a direction intersecting the moving direction of the punch pin by receiving a driving force from a drive source, and a sector pinion gear and / or a toothless pinion gear, and a gear conversion mechanism that meshes with the second rack gear of the slider and the first rack gear of the punch pin to convert the reciprocating motion of the slider into the moving motion of the punch pin. A sheet punching device that switches a punch pin that performs a punching operation by performing a reciprocating motion in one direction (F direction) and a reciprocating motion in the other direction (L direction) of the slider is disclosed. <00000十九>

[0006] Furthermore, Patent Document 2 discloses a sheet punching device that switches between a two-hole punch and a three-hole punch by changing the position of a cam that pushes down a bracket attached to the shaft, by sliding a support member that supports the shaft on a base using a motor. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2009-291881 [Patent Document 2] Japanese Patent Publication No. 2010-70385 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the configuration in Patent Document 1 required a large number of gears as a switching mechanism, which led to an increase in the number of parts and assembly steps, as well as a decrease in drilling accuracy due to gear backlash, etc. Furthermore, the configuration in Patent Document 2 required the use of a large motor with high torque in order to move both the shaft and the support member back and forth.

[0009] In view of the above problems, the present invention aims to provide a perforation device and a sheet post-processing device equipped therewith that can switch perforation patterns on a sheet with a compact configuration and shorten the switching time. [Means for solving the problem]

[0010] To solve the above problems, the first configuration of the present invention is a perforating device that includes a shaft, a perforating motor, an eccentric cam, a perforating section, a control unit, and a perforating switching mechanism, and performs perforation processing on a sheet. The perforating motor rotates the shaft. The eccentric cam is attached to the shaft. The perforating section is arranged along the axial direction of the shaft and has a perforating blade for making holes in the sheet and a biasing member that biases the perforating blade in a direction approaching the eccentric cam, and moves the perforating blade back and forth by the pressing force of the eccentric cam and the biasing force of the biasing member in accordance with the rotation of the eccentric cam. The control unit controls the driving of the perforating motor. The perforating section includes a first perforating section that performs a first perforation on the sheet with a first perforating blade, and a second perforating section that performs a second perforation on the sheet with a second perforating blade. The eccentric cam includes a first cam that reciprocates the first drilling blade of the first drilling section and the second drilling blade of the second drilling section, and a second cam that reciprocates only the first drilling blade of the first drilling section, with the first and second cams positioned axially separated from the shaft. The drilling switching mechanism reciprocates the shaft axially to select the shaft to be in a first position where the first cam faces the first and second drilling sections, and a second position where the second cam faces the first drilling section. The control unit can selectively perform a first drilling process, in which a first drill is made by the first drilling section and a second drill is made by the second drilling section in the sheet, by rotating the shaft while it is in the first position, and a second drilling process, in which only a first drill is made by the first drilling section in the sheet, by rotating the shaft while it is in the second position. The drilling switching mechanism includes a rack attached to a shaft and having rack teeth formed on its side, a drilling switching motor that reciprocates the shaft in the axial direction, and a pinion gear fixed to the rotating shaft of the drilling switching motor and meshing with the rack directly or via an idler gear. [Effects of the Invention]

[0011] According to the first configuration of the present invention, the first and second drilling processes can be switched simply by reciprocating the shaft in the axial direction to position it at a first and second position. Therefore, the time required to switch the drilling pattern is reduced, and processing efficiency (productivity) can be increased. In addition, the drilling device can be made smaller compared to a configuration in which the drilling pattern is switched by moving the shaft in the forward and backward direction (conveying direction). Furthermore, by using a rack attached to the shaft, a drilling switching motor that reciprocates the shaft in the axial direction, and a pinion gear fixed to the rotation axis of the drilling switching motor and meshing with the rack directly or via an idler gear as a drilling switching mechanism that reciprocates the shaft in the axial direction, the height dimension can be reduced while ensuring a switching stroke compared to a configuration in which the shaft is reciprocated using a solenoid, which is advantageous for miniaturizing the drilling device. [Brief explanation of the drawing]

[0012] [Figure 1] Block diagram showing an example of a control path for a paper post-processing device 2 equipped with the perforating device 1 of the present invention and an image forming apparatus 100 to which the paper post-processing device 2 is attached. [Figure 2] A schematic cross-sectional view showing an example of an image forming apparatus 100 with a paper post-processing device 2 attached. [Figure 3] Block diagram showing the control path of a drilling device 1 according to one embodiment of the present invention. [Figure 4] Perspective view of the perforation device 1 of this embodiment, viewed from the upstream side in the paper transport direction. [Figure 5] Enlarged view of the rotation speed detection unit 7 and home position detection unit 8 used in the drilling device 1 of this embodiment. [Figure 6] This is a side cross-sectional view showing the operation of the first drilling section 15a and the second drilling section 15b in the drilling device 1 of this embodiment, showing the state in which the first drilling blade 9a is retracted upward. [Figure 7] This is a side cross-sectional view showing the operation of the first drilling section 15a and the second drilling section 15b in the drilling device 1 of this embodiment, showing the first drilling blade 9a in a state where it is protruding downward. [Figure 8]Perspective view showing the arrangement of the shaft 12 when performing four-hole punching in the punching device 1 of the present embodiment [Figure 9] Perspective view showing the arrangement of the shaft 12 when performing two-hole punching in the punching device 1 of the present embodiment [Figure 10] Side view of the punching switching mechanism 90 in the punching device 1 of the present embodiment [Figure 11] Perspective view of the punching switching mechanism 90 in the punching device 1 of the present embodiment

Mode for Carrying Out the Invention

[0013] Hereinafter, with reference to FIGS. 1 to 11, the punching device 1 according to the present invention, the paper post-processing device 2 including the punching device 1, and the image forming apparatus 100 on which the paper post-processing device 2 is mounted will be described. However, each element such as the configuration and arrangement described in the present embodiment does not limit the scope of the invention and is merely an illustrative example.

[0014] (Outline of the image forming apparatus) FIG. 1 is a block diagram showing an example of a control path of a paper post-processing device 2 including the punching device 1 of the present invention and an image forming apparatus 100 to which the paper post-processing device 2 is attached. First, the control path of the image forming apparatus 100 (here, a multifunction peripheral) will be described based on FIG. 1.

[0015] The image forming apparatus 100 includes a main control unit 3 and a storage unit 3a. The main control unit 3 oversees the operation of the entire image forming apparatus 100 and controls each part of the image forming apparatus 100. The main control unit 3 includes a CPU 31, an image processing unit 32, and a communication unit 33. The CPU 31 performs calculations and controls related to control. The image processing unit 32 performs processing necessary for a job (printing) on the transmitted image data. The storage unit 3a includes storage devices such as a ROM, a RAM, and an HDD. The storage unit 3a stores control programs, image data, and the like. The communication unit 33 is an interface for communicating with a computer 200 such as a PC or a server. The communication unit 33 receives data indicating the printing content such as image data (printing data).

[0016] The main control unit 3 is communicably connected to the original document conveyance unit 4a and the image reading unit 4b. The original document conveyance unit 4a conveys the set original document toward the reading position. The image reading unit 4b can read the original document conveyed by the original document conveyance unit 4a and the original document set on the document table (contact glass, not shown). The image reading unit 4b generates image data. The main control unit 3 controls the operations of the original document conveyance unit 4a and the image reading unit 4b. The main control unit 3 is communicably connected to the operation panel 5. The operation panel 5 includes a display panel 51, a touch panel 52, and hard keys 53. The operation panel 5 receives the operations of the user.

[0017] The image forming apparatus 100 includes an image forming unit 6. The image forming unit 6 includes an engine control unit 60, a paper feeding unit 6a, a conveyance unit 6b, a transfer unit 6c, and a fixing unit 6d. The engine control unit 60 is communicably connected to the main control unit 3. The main control unit 3 transmits a printing instruction, the content of the printing job, and the image data used for printing to the engine control unit 60. Based on the instruction of the main control unit 3, the engine control unit 60 controls the operations of the paper feeding unit 6a, the conveyance unit 6b, the transfer unit 6c, and the fixing unit 6d. Specifically, the engine control unit 60 sequentially executes a paper feeding operation of feeding paper one by one to the paper feeding unit 6a, a conveyance operation of conveying the supplied paper to the conveyance unit 6b, an image forming operation of forming a toner image on the transfer unit 6c, a transfer operation of transferring the toner image to the paper in the transfer unit 6c, and a fixing operation of fixing the toner image transferred to the paper in the fixing unit 6d.

[0018] (Paper post-processing device 2) Next, the outline of the paper post-processing device 2 of the present embodiment will be described using FIGS. 1 and 2. FIG. 2 is a schematic cross-sectional view showing an example of the image forming apparatus 100 to which the paper post-processing device 2 of the present embodiment is attached.

[0019] The paper post-processing device 2 performs various post-processing on the printed paper discharged from the image forming apparatus 100. The paper post-processing device 2 is attached to the main body of the image forming apparatus 100. As shown in FIG. 2, the paper post-processing device 2 is attached (fitted) to the in-body discharge portion 101 of the image forming apparatus 100. There is also a type of paper post-processing device 2 that is attached to the side surface of the image forming apparatus 100.

[0020] The image-formed paper that has passed through the fixing unit 6d is fed into the paper post-processing device 2 from the input 102. The paper post-processing device 2 includes a punch hole forming unit 10, a paper transport unit 21, a stapling unit 22, a processing tray unit 23, and an output tray 24. As shown in Figure 1, the paper post-processing device 2 also includes a post-processing control unit 20 (corresponding to a control unit). The post-processing control unit 20 is a circuit board that includes a processing circuit 2a such as a CPU, a memory 2b, and a timing circuit 2c. The post-processing control unit 20 controls the operation of each part of the paper post-processing device 2. Alternatively, the post-processing control unit 20 may not be provided within the paper post-processing device 2, and the operation of the paper post-processing device 2 may be controlled by the main control unit 3 or engine control unit 60 of the image forming apparatus 100.

[0021] The paper post-processing device 2 includes a punching device 1. As shown in Figure 1, the punching device 1 includes a post-processing control unit 20 and a punch hole forming unit 10. When the setting for punching is made on the operation panel 5, the post-processing control unit 20 performs punching on the paper using the punch hole forming unit 10.

[0022] The paper transport unit 21 transports the paper that has passed through the punch hole forming unit 10 to the processing tray unit 23. The paper transport unit 21 includes a first transport roller pair 21a, a second transport roller pair 21b, and a paper transport guide 21c. The processing tray unit 23 includes a processing tray 23a, a first discharge roller 23b, a second discharge roller 23c, a stopper 23d, and a width regulating plate 23e. The post-processing control unit 20 aligns and discharges the stacks of paper that have been transported and loaded into the processing tray unit 23. When stapling is set on the operation panel 5, the post-processing control unit 20 uses the stapling unit 22 to perform stapling on the stacks of paper loaded into the processing tray unit 23 before discharge.

[0023] (Drilling device 1) Next, the perforation device 1 of this embodiment will be described using Figures 3 to 9. Figure 3 is a block diagram showing an example of the control path of the perforation device 1 according to one embodiment of the present invention. Figure 4 is a perspective view showing an example of the perforation device 1 of this embodiment. Figure 4 is a perspective view of the perforation device 1 viewed from the upstream side in the paper transport direction, with the direction of paper entry indicated by a dashed arrow. Figure 5 is an enlarged view of the rotation speed detection unit 7 and the home position detection unit 8 used in the perforation device 1 of this embodiment. Figures 6 and 7 are side cross-sectional views showing the operation of the first perforation unit 15a and the second perforation unit 15b in the perforation device 1 of this embodiment.

[0024] As shown in Figure 3, the punching device 1 includes a post-processing control unit 20 and a punch hole forming unit 10. The punch hole forming unit 10 includes a punching motor 11, a shaft 12, a motor drive unit 13, cams 14a and 14b, punching units 15a and 15b, a rotation speed detection unit 7, a home position detection unit 8, and a punch switching mechanism 90. The punching units 15a and 15b each include punching blades 9a and 9b, respectively. The white arrows in Figure 3 indicate the transmission paths of driving force from the punching motor 11 and the punch switching motor 91.

[0025] The drilling motor 11 causes the drilling blades 9a and 9b to reciprocate. For example, a DC brush motor can be used for the drilling motor 11. The motor drive unit 13 includes a plurality (four in this case) of switching elements 13a to 13d. The switching elements 13a to 13d turn the supply of current to the drilling motor 11 ON / OFF. The post-processing control unit 20 controls each of the switching elements 13a to 13d. The post-processing control unit 20 controls the motor drive unit 13 and performs brake control of the drilling motor 11.

[0026] As shown in Figure 4, the perforating device 1 has an upper guide section 16 and a lower guide section 17 that are positioned opposite each other at a predetermined distance apart. Multiple perforations 15a and 15b are provided above the upper guide section 16, and here we show an example where four perforations 15a and 15b are provided (corresponding to a 4-hole system). Specifically, the perforations 15a and 15b consist of a first perforation section 15a that forms two holes in the center of the paper in the width direction, and a second perforation section 15b that forms two holes at both ends of the paper in the width direction. The first perforation section 15a and the second perforation section 15b perform perforation on the paper as it passes between the upper guide section 16 and the lower guide section 17. Hereinafter, the perforating blades 9a and 9b arranged in the first perforation section 15a and the second perforation section 15b will be distinguished as the first perforation blade 9a and the second perforation blade 9b, respectively.

[0027] The shaft 12 is positioned to straddle the first perforation 15a and the second perforation 15b. The shaft 12 is rotatably supported by the support shaft member 12a. Cams 14a and 14b are attached to the shaft 12. The cams 14a and 14b consist of a first cam 14a and a second cam 14b. The first cam 14a is attached to four locations in the axial direction of the shaft 12 and is positioned corresponding to the two inner first perforations 15a and the two outer second perforations 15b. The second cam 14b is attached to two locations in the axial direction of the shaft 12 and is positioned adjacent to the first cam 14a corresponding to the two first perforations 15a. A cam cover 141 is attached above the first perforations 15a and the second perforations 15b, covering the first cam 14a and the second cam 14b. When the first drilling blade 9a and the second drilling blade 9b are pulled up, the first cam 14a and the second cam 14b rotate upward while sliding along the inner wall surface of the cam cover 141. In other words, the cam cover 141 assists the movement of the first cam 14a and the second cam 14b when pushing up the first drilling blade 9a and the second drilling blade 9b by the biasing force of the coil spring 19.

[0028] The shaft 12 is connected to the rotating shaft of the drilling motor 11 via a gear, and as the drilling motor 11 rotates the shaft 12, the first cam 14a and the second cam 14b rotate together with the shaft 12. For example, when the drilling motor 11 rotates once, the shaft 12 rotates once.

[0029] As shown in Figure 5, the rotation speed detection unit 7 detects the rotation speed of the shaft 12 (drilling motor 11). The rotation speed detection unit 7 includes a first pulse plate 71 and a first sensor unit 72. The first sensor unit 72 is a transmissive optical sensor. The first sensor unit 72 includes a light-emitting unit 73 and a light-receiving unit 74. The first pulse plate 71 is attached to the shaft 12. The light-emitting unit 73 and the light-receiving unit 74 are arranged to sandwich the outer edge of the first pulse plate 71 attached to the shaft 12.

[0030] The first pulse plate 71 is held so as to be slidable in the axial direction while its rotation in the circumferential direction is restricted relative to the shaft 12. As a result, when the shaft 12 is moved back and forth in the axial direction, as will be described later, the first pulse plate 71 does not move in the axial direction, and therefore the positional relationship between the first pulse plate 71 and the first sensor unit 72 does not change. As a method for holding the first pulse plate 71 so as to be slidable only in the axial direction relative to the shaft 12, for example, a rib extending in the axial direction is formed on the outer circumferential surface of the shaft 12, and a groove is formed on the first pulse plate 71 that slidably engages with the rib.

[0031] Multiple slits 71a are provided on the first pulse plate 71. For example, the number of slits 71a is several tens to several hundred (for example, 40 to 50). The slits 71a are provided on the outer edge of the first pulse plate 71 sandwiched between the light-emitting unit 73 and the light-receiving unit 74. The slits 71a are formed at regular intervals, and the output of the first sensor unit 72 (light-receiving unit 74) changes each time the shaft 12 rotates by a certain angle. The output of the light-receiving unit 74 when the first pulse plate 71 rotates between the light-emitting unit 73 and the light-receiving unit 74 is the output of the rotation speed detection unit 7. The output of the light-receiving unit 74 is a pulse signal that rises or falls each time the shaft 12 (drilling motor 11) rotates by a certain angle. The output of the light-receiving unit 74 is input to the post-processing control unit 20. The post-processing control unit 20 detects that the shaft 12 has rotated by a certain angle based on the output of the first sensor unit 72.

[0032] Furthermore, the post-processing control unit 20 detects the rotational speed of the shaft 12 (drilling motor 11) based on the pulse period of the pulse signal. More specifically, the post-processing control unit 20 detects the rotational speed of the shaft 12 based on the time interval between the rising edge or falling edge of the pulse signal. Therefore, the timing circuit 2c within the post-processing control unit 20 measures the period (edge ​​interval) of each pulse signal.

[0033] Let's explain how to determine the rotational speed (rps) of the shaft 12 per second. In this case, the post-processing control unit 20 divides 1 (second) by the period of one pulse. This calculates the number of pulses A per second in the current period. Then, the post-processing control unit 20 divides the number of pulses A by the number of pulses B (number of slits in the first pulse plate 71) that are generated when the shaft 12 completes one rotation. This allows us to determine the rotational speed of the shaft 12. To find rpm, multiply by 60. For example, when the period of one pulse is 10 milliseconds, the number of pulses A = 100. When the number of pulses B is 50, the number of rotations per second = 100 / 50 = 2 [rps].

[0034] The home position detection unit 8 detects when the rotation angle of the shaft 12 (drilling motor 11) reaches a predetermined reference angle, and detects whether or not the drilling blade 9 is in the home position. The home position detection unit 8 includes a second pulse plate 81 and a second sensor unit 82. The second sensor unit 82 is a transmissive optical sensor. The second sensor unit 82 includes a light-emitting unit 83 and a light-receiving unit 84 (see Figure 3). The light-emitting unit 83 and the light-receiving unit 84 are arranged to sandwich the outer edge of the second pulse plate 81 attached to the shaft 12.

[0035] The second pulse plate 81 is held so as to be slidable in the axial direction while its rotation in the circumferential direction is restricted relative to the shaft 12. As a result, when the shaft 12 is moved back and forth in the axial direction, as will be described later, the second pulse plate 81 does not move in the axial direction, and therefore the positional relationship between the second pulse plate 81 and the second sensor unit 82 does not change. The method of holding the second pulse plate 81 so as to be slidable only in the axial direction relative to the shaft 12 is the same as that for the first pulse plate 71 described above.

[0036] A notch 81a is provided on the outer edge of the second pulse plate 81. The notch 81a is formed at a position where the output of the second sensor unit 82 (light receiving unit 84) changes when the angle of the shaft 12 reaches the reference angle. The output of the light receiving unit 84 when the second pulse plate 81 rotates between the light emitting unit 83 and the light receiving unit 84 is the output of the home position detection unit 8. The output of the light receiving unit 84 is transmitted to the post-processing control unit 20 as a detection signal. Based on the output of the home position detection unit 8, the post-processing control unit 20 detects that the angle of the shaft 12 has reached the reference angle.

[0037] In this embodiment, a notch 81a is provided at one location on the second pulse plate 81 in order to detect one rotation of the shaft 12 during two-hole and four-hole drilling.

[0038] Here, the position where the paper being transported does not come into contact with the first punching blade 9a and the second punching blade 9b is defined as the home position of the punching blade 9. In other words, when the first punching blade 9a and the second punching blade 9b are in their home position, the first punching blade 9a of the first punching section 15a and the second punching blade 9b of the second punching section 15b are both retracted (separated) from the paper.

[0039] Specifically, the home position is the range of positions that the first drilling blade 9a and the second drilling blade 9b can take when the home position detection unit 8 detects that the shaft 12 has reached the reference angle, and the output of the rotation speed detection unit 7 rotates the shaft 12 in the forward direction by a predetermined number of pulses (alignment pulses). For example, if the number of alignment pulses is 2, the reference angle is the angle of the shaft 12 when it has rotated forward by 2 pulses of the rotation speed detection unit 7 from the position where the first drilling blade 9a and the second drilling blade 9b are in the home position. Therefore, at 1 pulse and 3 pulses from the reference angle, the position is outside the home position. If the number of slits 71a in the first pulse plate 71 is 36, the rotation angle per pulse is 360 / 36 = 10°.

[0040] When the main power to the image forming apparatus 100 or the paper post-processing device 2 is turned on, the post-processing control unit 20 performs a startup process. The startup process includes setting the punching blade 9 to the home position. In this case, the post-processing control unit 20 rotates the punching motor 11 in the forward direction at a low speed, and after the home position detection unit 8 detects that the shaft 12 has reached the reference angle, the post-processing control unit 20 stops the punching motor 11 when the output of the rotation speed detection unit 7 changes by the number of alignment pulses.

[0041] As shown in Figures 6 and 7, the first drilling section 15a and the second drilling section 15b each have a first drilling blade 9a, a second drilling blade 9b, a contact member 18, and a coil spring (biasing member) 19, respectively. The first drilling blade 9a and the second drilling blade 9b are, for example, metal pipes with blades formed at their lower ends. The contact member 18 is provided above the first drilling blade 9a and the second drilling blade 9b, and the upper ends of the first drilling blade 9a and the second drilling blade 9b are fixed to the contact member 18.

[0042] The upper guide section 16 and the lower guide section 17 have holes (not shown) positioned opposite the first punching blade 9a and the second punching blade 9b. The first punching blade 9a and the second punching blade 9b move downward so that their lower ends hit the paper, and then the first punching blade 9a and the second punching blade 9b move further downward to punch holes in the paper. After punching, the first punching blade 9a and the second punching blade 9b retract upward so as not to interfere with the punching process of the next sheet of paper being transported.

[0043] A contact member 18 is provided below the shaft 12 and the first cam 14a and second cam 14b. As shown in Figure 6, the first cam 14a and second cam 14b are elliptical in shape when viewed from the axial direction of the shaft 12, and the outer surfaces of the first cam 14a and second cam 14b contact the upper surface of the contact member 18. The contact member 18 is biased upward by a coil spring 19. When the shaft 12 rotates due to the driving force of the drilling motor 11, the outer diameters of the parts of the first cam 14a and second cam 14b that contact the contact member 18 change according to the rotation angle of the shaft 12. That is, the amount of pressure the first cam 14a and second cam 14b apply to the contact member 18 changes according to the rotation angle of the shaft 12.

[0044] As shown in Figure 6, when the small-diameter portions of the first cam 14a and the second cam 14b are in contact with the contact member 18, the contact member 18 rises due to the biasing force of the coil spring 19, and the first drilling blade 9a and the second drilling blade 9b also retract upward. On the other hand, as shown in Figure 7, when the large-diameter portions of the first cam 14a and the second cam 14b are in contact with the contact member 18, the contact member 18 is pushed down against the biasing force of the coil spring 19, and the first drilling blade 9a and the second drilling blade 9b protrude downward. In this way, the first drilling blade 9a and the second drilling blade 9b reciprocate in accordance with the rotation of the first cam 14a.

[0045] Figures 8 and 9 are perspective views showing the arrangement of the shaft 12 when performing 4-hole punching and 2-hole punching, respectively, in the punching device 1 of this embodiment. For convenience of explanation, the first punching blade 9a, the second punching blade 9b, the coil spring 19, and the cam cover 141 are omitted from Figures 8 and 9. The following describes the switching between 4-hole punching (first punching process), which forms a total of 4 holes (2 holes each in the center and both ends of the paper in the width direction), and 2-hole punching (second punching process), which forms 2 holes in the center of the paper in the width direction, in the punching device 1 of this embodiment, with reference to Figures 6 to 9.

[0046] When performing four-hole punching, as shown in Figure 8, the shaft 12 is positioned at a location (first position) where the first cams 14a attached to four locations on the shaft 12 contact the contact members 18 of the first punching section 15a and the second punching section 15b. In this state, the shaft 12 is started to rotate forward from the home position (see Figure 6, the position rotated by the number of alignment pulses from the detection timing of the notch 81a). This causes the first cams 14a to push down the first punching section 9a and the second punching section 9b together with the contact members 18. Then, when the shaft 12 is rotated 90° from the home position, the first punching section 9a and the second punching section 9b descend to the position where they pierce the paper (see Figure 7, below the lower guide section 17). As a result, the two inner holes are drilled by the two first perforations 15a, and the two outer holes are drilled by the two second perforations 15b.

[0047] Subsequently, when the post-processing control unit 20 further rotates the shaft 12 in the forward direction, the amount by which the first cam 14a pushes down the contact member 18 decreases, and the first punching blade 9a and the second punching blade 9b move upward due to the biasing force of the coil spring 19. As the forward rotation of the shaft 12 continues, the second punching blade 9b of the second punching unit 15b is raised to a position that does not obstruct paper transport (above the upper guide unit 16). The post-processing control unit 20 stops the punching motor 11 so that the first punching blade 9a and the second punching blade 9b return to their home positions. By repeating the above operation, four holes are punched by the two first punching units 15a and the two second punching units 15b.

[0048] When performing two-hole drilling, the drilling switching motor 91 (see Figure 10) is rotated forward, causing the shaft 12 to move axially by a predetermined amount from the state shown in Figure 8, as shown in Figure 9. The shaft 12 is then positioned at a location (second position) where the second cams 14b attached to two locations on the shaft 12 contact the contact member 18 of the first drilling section 15a. At this time, the four first cams 14a are positioned axially offset from the first drilling section 15a and the second drilling section 15b.

[0049] In this state, the shaft 12 is started to rotate forward from the home position (see Figure 6) where the first punching blade 9a is. This causes the second cam 14b, together with the contact member 18, to push down the first punching blade 9a. Then, when the shaft 12 is rotated 90° from the home position, the first punching blade 9a descends to the position where it penetrates the paper (see Figure 7). As a result, the two inner holes are punched by the two first punching sections 15a.

[0050] Subsequently, when the post-processing control unit 20 rotates the shaft 12 further in the forward direction, the amount by which the second cam 14b pushes down the contact member 18 decreases, and the first punching blade 9a moves upward due to the biasing force of the coil spring 19. As the forward rotation of the shaft 12 continues, the first punching blade 9a of the first punching unit 15a is raised to a position that does not obstruct paper transport (above the upper guide unit 16). The post-processing control unit 20 stops the punching motor 11 so that the first punching blade 9a returns to the home position. By repeating the above operation, two holes are punched by the two first punching units 15a.

[0051] Figure 10 is a side view of the drilling switching mechanism 90 in the drilling device 1 of this embodiment. Figure 11 is a perspective view of the drilling switching mechanism 90 in the drilling device 1 of this embodiment. As shown in Figures 10 and 11, the drilling switching mechanism 90 comprises a drilling switching motor 91, a rack 93, and an idler gear 95.

[0052] The drilling switching motor 91 is fixed to the lower guide section 17 by a motor holding frame 96. A pinion gear 91a is fixed to the rotating shaft 91b of the drilling switching motor 91.

[0053] The rack 93 is held at one end of the shaft 12 (the front side of the paper in Figures 8 and 9). The rack 93 has rack teeth 93a, a light-shielding plate 93b, and a guide portion 93c. The rack teeth 93a are formed on the surface facing the idler gear 95 (the front side of the paper in Figure 10) and mesh with the small diameter portion 95b of the idler gear 95. The light-shielding plate 93b is formed on the surface facing the motor holding frame 96. As the shaft 12 moves back and forth in the axial direction, the light-shielding plate 93b transmits and blocks light from the detection portion of the shaft position detection sensor 97 located on the motor holding frame 96. The post-processing control unit 20 detects the movement of the shaft 12 to a first position or a second position based on the output of the shaft position detection sensor 97.

[0054] The idler gear 95 is a two-stage gear having a large-diameter section 95a and a small-diameter section 95b. The large-diameter section 95a of the idler gear 95 meshes with the pinion gear 91a. The small-diameter section 95b of the idler gear 95 meshes with the rack teeth 93a. With this configuration, the rotational driving force of the drilling switching motor 91 is transmitted to the rack 93 via the idler gear 95. By rotating the drilling switching motor 91 in forward and reverse directions, the shaft 12 reciprocates axially together with the rack 93 to be positioned at a first position (see Figure 8) and a second position (see Figure 9).

[0055] The rack 93 is restricted from axial movement relative to the shaft 12, and Circumference of shaft 12 It is held so as to be slidable in the direction. In addition, the rotation axis 95c of the idler gear 95 is slidably engaged with the guide portion 93c. As a result, when the shaft 12 is rotated, the rack 93 does not rotate with it, and when the shaft 12 is moved back and forth in the axial direction, the positional relationship between the rack teeth 93a and the idler gear 95 does not change. Therefore, the meshing state between the rack teeth 93a and the idler gear 95 can be maintained regardless of the phase (rotation angle) of the shaft 12.

[0056] One method for holding the rack 93 so that it can slide radially only relative to the shaft 12 is to insert the shaft 12 through a through hole formed in the rack 93 to attach the rack 93 to the shaft 12, and then to fit stop rings (not shown) into locking grooves formed at two locations in the axial direction of the shaft 12 to fix it, thereby restricting the axial movement of the rack 93. Another method for restricting the rotation of the rack 93 around the shaft 12 is to insert the rotating shaft 95c of the idler gear 95 into the guide portion 93c of the rack 93, and then to fit stop rings (not shown) onto the rotating shaft 95c to fix it.

[0057] According to the drilling device 1 of this embodiment, the shaft 12 has a first cam 14a positioned corresponding to the two inner first drilling portions 15a and the two outer second drilling portions 15b, and a second cam 14b positioned corresponding only to the first drilling portion 15a. With the shaft 12 positioned at a first position where the first cam 14a contacts the contact members 18 of the first drilling portions 15a and the second drilling portions 15b, four holes are drilled using the first drilling portions 15a and the second drilling portions 15b by rotating the shaft 12 once. Also, with the shaft 12 positioned at a second position where the second cam 14b contacts the contact member 18 of the first drilling portion 15a, two holes are drilled using the first drilling portion 15a by rotating the shaft 12 once.

[0058] This allows switching between 4-hole drilling and 2-hole drilling simply by reciprocating the shaft 12 in the axial direction to position it between the first and second positions. Consequently, the time required to switch drilling patterns is reduced, and processing efficiency (productivity) can be increased.

[0059] Furthermore, compared to a configuration in which the drilling pattern is switched by moving the shaft 12 in the forward / backward direction (conveying direction), the drilling device 1 can be made smaller. In addition, by using a gear mechanism (rack and pinion mechanism) as shown in Figure 10 as the drilling switching mechanism 90, the switching stroke can be secured even when the position of the shaft 12 is lowered, compared to a configuration using a solenoid, which is advantageous for miniaturizing the drilling switching mechanism 90.

[0060] Furthermore, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. For example, in the above embodiment, four holes are formed along the width direction of the paper by two first perforations 15a and two second perforations 15b, and two holes are formed in the center of the paper in the width direction by two first perforations 15a, thereby enabling switching between four-hole perforation and two-hole perforation. However, the placement locations and number of the first perforations 15a and second perforations 15b can be arbitrarily set.

[0061] Furthermore, in the above embodiment, the drilling switching mechanism 90 is configured to include a drilling switching motor 91, a rack 93, and an idler gear 95, but it is not limited to this configuration, and two or more idler gears 95 may be provided. Alternatively, the pinion gear 91a of the drilling switching motor 91 may be configured to directly mesh with the rack teeth 93a of the rack 93. [Industrial applicability]

[0062] The present invention is applicable to perforating devices and sheet post-processing devices including perforating devices. By utilizing the present invention, it is possible to provide a perforating device and a sheet post-processing device equipped therewith that can switch perforation patterns on a sheet in a compact configuration and shorten the switching time. [Explanation of Symbols]

[0063] 1 Drilling device 7. Rotational speed detection unit 8. Home position detection unit 9a 1st drilling blade 9b 2nd drilling blade 10 Punch hole forming section 11 Drilling motor 12 shafts 14a First Cam 14b Second Cam 15a 1st drilling part 15b 2nd drilling part 18 Contact Member 19. Coil spring (biasing member) 20 Post-processing control unit (control unit) 71 First pulse plate 72 First Sensor Section 81 Second pulse plate 82 Second Sensor Section 90 Perforation switching mechanism 91 Drilling Switching Motor 91a Pinion Gear 91b Rotation axis 93 racks 95 Idol Gear 100 Image forming apparatus

Claims

1. The shaft and A drilling motor that rotates the aforementioned shaft, An eccentric cam attached to the aforementioned shaft, The perforating section comprises perforating blades arranged along the axis of the shaft for making holes in the sheet, and a biasing member that biases the perforating blades toward the eccentric cam, and moves the perforating blades back and forth in accordance with the rotation of the eccentric cam by the pressing force of the eccentric cam and the biasing force of the biasing member, A control unit that controls the drive of the drilling motor, A perforating device that includes and performs perforation processing on the sheet, The perforating section includes a first perforating section that performs a first perforation in the sheet using a first perforating blade, and a second perforating section that performs a second perforation in the sheet using a second perforating blade. The eccentric cam includes a first cam that reciprocates the first drilling blade of the first drilling section and the second drilling blade of the second drilling section, and a second cam that reciprocates only the first drilling blade of the first drilling section, wherein the first cam and the second cam are positioned spaced apart in the axial direction with respect to the shaft. The system includes a drilling switching mechanism that reciprocates the shaft in the axial direction to select the shaft to be positioned in a first position where the first cam faces the first and second drilling portions, and in a second position where the second cam faces the first drilling portion. The control unit, A first perforation process is performed by rotating the shaft while it is positioned in the first position, thereby performing a first perforation by the first perforation part and a second perforation by the second perforation part on the sheet. By rotating the shaft while it is positioned in the second position, a second perforation process is performed in which only the first perforation is made in the sheet by the first perforation section. It is possible to selectively execute, The aforementioned perforation switching mechanism is A rack attached to the aforementioned shaft, with rack teeth formed on its side, A drilling switching motor that reciprocates the shaft in the axial direction, A pinion gear fixed to the rotating shaft of the drilling switching motor, which meshes with the rack via an idler gear, Includes, The drilling device is characterized in that the rack has an elongated guide portion into which the rotation shaft of the idler gear slidably engages.

2. The drilling device according to claim 1, characterized in that the rack is held so as to be rotatable in the circumferential direction of the shaft and its movement in the axial direction is restricted with respect to the shaft.

3. The first perforations are located at two locations in the center of the sheet in the width direction, and the second perforations are located at both ends of the sheet in the width direction. The perforating device according to claim 1 or 2, characterized in that the first perforation process is a four-hole perforation in which the first perforation section and the second perforation section perforate four locations in the width direction of the sheet, and the second perforation process is a two-hole perforation in which the first perforation section perforates two locations in the width direction of the sheet.

4. A rotation speed detection unit for detecting the rotation speed of the shaft, A home position detection unit that detects whether the first and second drilling blades are in a home position separated from the sheet, Equipped with, The rotation speed detection unit and the home position detection unit are, A pulse plate that rotates together with the shaft, A sensor unit is positioned so as to sandwich the outer edge of the pulse plate, Includes, The drilling device according to any one of claims 1 to 3, characterized in that the pulse plate is held so as to be slidable in the axial direction and its rotation in the circumferential direction is restricted with respect to the shaft.

5. A sheet post-processing device comprising a perforating device according to any one of claims 1 to 4.

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