JP5912257B2 - Paper punching device - Google Patents

Description

  The present invention relates to a paper sheet punching apparatus that punches filing holes in a sheet conveyed from an image forming apparatus such as a copying machine, a printing machine, or a printer, and relates to an improvement of a punching mechanism that punches a plurality of holes in a paper sheet.

  Generally, a punching device that punches filing punch holes in sheets (paper sheets) that are sequentially carried out is used as a post-processing device such as an image forming device. For example, in Patent Document 1, a sheet is set between an upper frame and a lower frame, a plurality of punch members are supported on the upper frame so as to be movable up and down, and a die (blade receiving hole) adapted to each punch member is supported on the lower frame. ) And moving the punch member up and down with a drive motor is disclosed.

  In this document, a slide cam that reciprocates at a predetermined stroke is provided on the upper frame, a cam pin of a punch member is engaged with a V-groove cam formed on the slide cam, and the slide cam is reciprocated by a drive motor. A punching mechanism for causing each punch member to perform a punching operation is disclosed.

  Further, Patent Document 2 is provided with a rack in which a plurality of punch members arranged linearly as in Patent Document 1 are reciprocated with a predetermined stroke in the direction of the punch row, and each punch member is rotated by this rack. And a drive mechanism that reciprocates in the drilling direction by a cam mechanism between the punch member and the frame has been proposed.

JP 2001-009791 A (FIGS. 14 and 15) JP 2008-036752 (FIG. 1)

  A punching mechanism for reciprocating a plurality of punch members arranged in a straight line as described above in the drilling direction by a drive member (sliding member) reciprocating in the arrangement direction is already known in Patent Documents 1 and 2, etc. . In this case, in the method of Patent Document 1, a cam is provided on a slide plate and a cam pin of a punch member is engaged with the cam to perform a perforating motion (FIG. 1 of the same document) and a toothed belt in a direction crossing the punch row. Is arranged so as to reciprocate with a predetermined stroke, and a mechanism (FIG. 14 of the same document) is disclosed in which a cam and a cam pin are arranged between a gear meshed with the toothed belt and a punch member.

  In Patent Document 2, a rack is provided in a direction intersecting with a plurality of punch members arranged in a straight line, and the punch is rotated in a predetermined direction by the reciprocating motion of the rack, and a cam mechanism disposed between the punch and the frame. A mechanism for moving the punch in the drilling direction is disclosed.

  In this way, the plurality of punch members are arranged in, for example, 2 holes, 3 holes, 4 holes, etc. at a standardized interval in order to punch file holes in the paper sheet. At this time, five punch members are arranged on a straight line in the apparatus specification for punching with two holes and three holes, and four punch members are arranged on a straight line in the apparatus specification with two holes and four holes being switched. The plurality of punch members arranged in this way uses a drive mechanism that moves in the perforating direction by a member (rack, toothed belt, etc.) that reciprocates in the same direction (perforation orthogonal direction) as the arrangement direction.

  FIG. 8 shows an example of this drive mechanism. A plurality of punch members 101 are linearly arranged on the apparatus frame and supported so as to be movable in the drilling direction. A rack 102 (same as a toothed belt) that reciprocates with a predetermined stroke in the arrangement direction of the punches is slidably attached to the frame, and a drive motor (not shown) is connected to the rack. The drive teeth 103 of the rack 102 are meshed with passive gears 104 formed integrally with the punch members 101.

  Accordingly, when the rack 102 is moved at a predetermined stroke St, the punch is rotated counterclockwise when moving in the arrow direction of the figure, and the punch is rotated clockwise when moving in the opposite direction. Each punch member 101 is provided with a cylindrical cam (not shown) together with the passive gear 104, and this cylindrical cam is engaged with a cam pin (cam follower) fixed to the frame. Accordingly, the plurality of punch members 101 supported on the frame so as to be movable up and down in the perforating direction rotate in the forward and reverse directions by the reciprocating motion of the rack 102. The punch members are moved up and down in the perforating direction by the cylindrical cams provided on the punch members.

  In such an apparatus configuration, a plurality of punch members are arranged. The punch intervals (L1, L2) are preset according to the file hole specifications, and the punch intervals cannot be changed. Therefore, the punch member interval is set to be constant regardless of whether it has a four-punch configuration (two-hole four-hole switching) or a five-punch configuration (three-hole four-hole switching). The stroke for transmitting the rotation operation to the plurality of punch members or the stroke length of the toothed belt 102 is also set to be constant.

  For this reason, the minimum length of a transmission member such as a rack or a toothed belt is a sum total (Lz = L1 + L2 + 2St) twice the punch interval (L1, L2) and the drive stroke St. Accordingly, the unit length (Lz) of the punch unit is twice the sum of the total punch interval and the drive stroke, so there is a problem that the unit size becomes large.

  Therefore, the present inventor, when transmitting the rotation to a plurality of punch members, when the gear member is connected to a transmission member such as a rack or a toothed belt that reciprocates with a predetermined stroke, the punch located at the left end or the right end The idea is that the member and the transmission member are connected via an intermediate gear, and the gear train direction is set to the moving stroke direction of the transmission member.

  In the present invention, when a plurality of punch members are arranged in a straight line and the rotation member is reciprocated in the arrangement direction and the rotation operation is transmitted to each punch member, the stroke length of the transmission member can be set short. An object of the present invention is to provide a paper sheet punching device that can reduce the size of the device.

In order to achieve the above object, according to the present invention, a plurality of punch members are linearly arranged on a base frame, and a transmission member that reciprocates with a predetermined stroke in the row direction is arranged. When the drive teeth formed on the transmission member and the driven teeth formed on the punch members are meshed, the punch member and the drive teeth positioned at least one of the right limit position and the left limit position of the transmission member are excluded from the predetermined range. It is characterized by being connected via an intermediate gear having a diameter.

  In this case, the drive teeth, the driven teeth, and the intermediate gear are arranged substantially linearly in the reciprocating direction of the transmission member, and the connecting position of the punch member and the transmission member set at a predetermined interval is set at the center in the reciprocating direction. Offset a predetermined amount to the part side. As a result, the length of the punch unit in the punch row direction can be set small, and the apparatus can be made compact and compact.

  More specifically, the structure includes a base frame (30), a plurality of punch members (40) arranged on the base frame, and a driving means for reciprocating each punch member in the punching direction. The members are arranged in a substantially straight line at predetermined intervals on the base frame, and the driving means has a driving motor (M) and a right limit position (RL) at a predetermined stroke in a direction intersecting the drilling direction by rotation of the driving motor. A transmission member (50) reciprocating between the left limit position (LL), a drive tooth (51) formed on the transmission member, and a driven tooth (46) formed on each punch member. The drive teeth and the driven teeth mesh with each other so as to move up and down in the drilling direction while rotating each punch member, and the punch member (40) located at at least one of the right limit position and the left limit position of the transmission member is The driven teeth and the drive teeth of the transmission member are connected via an intermediate gear (47) having a predetermined outer diameter.

  The transmission member (50) is constituted by a rack supported on the base frame so as to be reciprocally movable.

  Between the base frame and the plurality of punch members, a cam (44) for converting the rotation of the punch member into a movement in the punching direction is provided on one side, and a cam follower (33) for engaging the cam is provided on the other side.

  When the punch member (40) located at at least one of the left limit position and the right limit position of the transmission member connects the driven tooth (46) and the intermediate gear (47), the driven tooth moves the transmission member. The intermediate gear is disposed outside the area and within the movement area of the transmission member.

  The plurality of punch members are composed of four punch members, and are connected to the driving means so as to selectively execute 2-hole drilling and 4-hole drilling.

The present invention relates to punches positioned on the outer side (frontmost row or last row) in the arrangement direction when a rotational motion is transmitted to a plurality of punch members arranged linearly by a transmission member that reciprocates with a predetermined stroke in the arrangement direction. Since the driven teeth of the member and the driving teeth formed on the transmission member are gear-coupled via an intermediate gear having a predetermined outer diameter, the following effects are produced.

  In the present invention, a transmission member that reciprocates in the punch arrangement direction and a punch member located at the outermost side in the punch arrangement direction (in the right limit position or the left limit position) are gear-coupled via an intermediate gear. Therefore, the operating region of the transmission member can be set small by offsetting the intermediate gear and the drive teeth of the transmission member toward the center in the moving direction.

  Therefore, a plurality of punch members can be arranged at predetermined intervals, and the movement space of the transmission member for transmitting the rotational motion to the punch members can be reduced. At the same time, it is possible to further reduce the moving space of the transmission member by enlarging the intermediate gear with a plurality of gear trains or gear outer diameters.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the punching apparatus concerning this invention. It is explanatory drawing of the principal part in the apparatus of FIG. 1, (a) shows the cross-section of the apparatus of FIG. 1, (d) is the expanded view of a cam surface. Explanatory drawing of the arrangement structure of the punch member in the apparatus of FIG. The conceptual diagram which showed the relationship between the punch member and intermediate | middle gear in the apparatus of FIG. It is a block diagram of the position sensor of the drive mechanism in FIG. 1 apparatus, (a) is the top view, (b) is sectional drawing. (A) thru | or (e) Explanatory drawing of the operation state in the position sensor of FIG. 1 shows a configuration of a post-processing apparatus in an image forming apparatus according to the present invention, (a) is an overall view, and (b) shows a punching apparatus. An example of the drive mechanism in the conventional drilling apparatus.

The present invention will be described in detail below based on the preferred embodiments shown in the drawings.
FIG. 1 shows a case where the present invention is applied to a punch unit that automatically forms file holes in a sheet image-formed by an image forming apparatus or the like.

  The punch unit A includes a base frame (upper frame 30 and lower frame 35) and a plurality of punch members 40 (40a, 40b, 40c, 40d) attached to the upper frame 30 so as to be capable of reciprocating in the drilling direction (vertical direction in FIG. 1). ) And a lower frame 35 having a die (blade receiving hole) 38 adapted to the punching blade 41 formed in each punch member.

The upper frame 30 and the lower frame 35 are arranged so as to face each other vertically with a gap Sd for setting a perforated sheet S (hereinafter simply referred to as “sheet”), and the length dimension (FIG. 1Lx) is the width direction of the sheet It is formed larger than the length. A plurality of punch members 40 are linearly arranged on the upper frame 30, and each punch interval Ls is set to a predetermined standard (file hole standard). The form shown in FIG. 1 shows a case in which 2-hole perforation and 4-hole perforation are selectively formed in the sheet. In this case, Ls1 = Ls2 = Ls3 is set. Then, 2-hole drilling is executed with the two punch members 40b and 40c, and 4-hole drilling is executed with the four punch members 40a to 40d.

  In addition, the punch member 40 may have a configuration in which five punches are linearly arranged so as to selectively perform two-hole drilling and three-hole drilling, or single-function drilling such as two-hole drilling, three-hole drilling, and four-hole drilling. Can also be arranged

  The punch member 40 is formed in a normal cylindrical shape, and a drilling blade 41 is provided at the tip thereof. The illustrated first to fourth punch members 40a to 40d have the same structure, and one of them will be described with reference to FIG. The upper frame 30 is composed of a channel member having a U-shaped cross section, and guide holes 31 a and 32 a are provided in an upper guide 31 and a lower guide 32 that face each other in the vertical direction. The punch members 40a to 40d are fitted and supported by the guide hole 31a with the upper shaft portion 42a and the guide hole 32a with the lower shaft portion 42b. Therefore, the punch member 40 is supported by the upper frame 30 so as to be slidable in the vertical direction (perforation direction) in FIG. The lower frame 35 is provided with a blade receiving hole 38 that fits the perforating blade 41. The lower frame 35 is attached to the upper frame 30 integrally with a fixing screw while forming the gap Sd.

"Cam mechanism"
The plurality of punch members 40 are provided with cam means (cylindrical cam 44 in the figure) that receives the rotational motion from the drive motor M and converts the rotational motion into the drilling direction. A cylindrical cam 44 is formed integrally with each of the punch members 40a to 40d, and this cam is constituted by a cam groove 45 having an inclined cam surface 45θ.

  As will be described later, the cam groove 45 converts a rotational motion acting on the punch member 40 into a motion that moves in the drilling direction while using a rotor. Therefore, a cam follower member (cam pin) 33 that is engaged with the cam groove 45 is fixed to the upper frame 30. The cam follower member 33 is provided with a guide shaft portion and has a function of slidably guiding a transmission member (slide plate: the same applies hereinafter) 50 described later.

Further, a driven tooth 46 is integrally attached to each punch member 40. The driven gear 46 is engaged with a rack 51 constituting “driving means” described later, and is connected to a drive motor M. In the punch member 40 configured in this way, the punching blade 41 and the upper and lower shaft portions 42a and 42b are made of a material having good polishing properties such as SUS steel. In addition, it may be formed of iron-based metal or ceramic.

  The cylindrical cam 44 and the driven tooth 46 are preferably molded from a synthetic resin such as POM (Duracon resin) from the viewpoint of workability and silence, but the material is not particularly specified. Then, the punching blade 41 of the punch member 40, the cylindrical cam 44, and the driven tooth 46 are integrated. This integration is for these three members to rotate integrally, and is integrated by insert molding at the time of molding, or is fixed with a fixing screw, a penetration pin, an adhesive or the like.

  The punching blade 41 provided at the front end of the punch member 40 has a front end surface that is cut into a wave shape such as a U-shaped cross section or a V shape, and an end surface that comes into contact with the sheet S is formed in an uneven shape. This is to increase the shearing force when punching while rotating the punch member 40 in the radial direction at the same time that the punching blade 41 penetrating the sheet S is formed sharply. Further, the shape of the perforating blade 41 can be further increased in shearing action at the time of perforation by configuring the perforation blade 41 in an oblique shape with a sharp tip.

"Configuration of drive means"
The structure of the driving means for reciprocating the punch members 40 in the punching direction will be described. As shown in FIG. 1, the “driving means” for rotating each punch member 40 includes a drive motor M and a right limit position RL and a left limit position LL with a predetermined stroke in a direction intersecting the drilling direction by the rotation of the drive motor. , A drive tooth (rack) 51 formed on the transmission member, and a driven tooth 46 formed on each punch member 40.

  A drive motor M is coupled to the transmission member 50 as shown in FIG. A drive motor M is attached to the upper frame 30 by a bracket 53, and its rotation shaft is connected to the drive gear G1 via a reduction gear. The drive gear G1 meshes with the drive teeth (rack) 51 of the transmission member 50. Therefore, the transmission member 50 moves in the left-right direction in FIG. 54 is an encoder provided on the rotating shaft of the motor, and Se is an encode sensor for detecting this.

  Therefore, the present invention is characterized in that the transmission member 50 reciprocating at a predetermined stroke and the plurality of punch members 40a to 40d are drive-connected as follows. A plurality of punch members 40 arranged in a straight line and a transmission member 50 reciprocating in the row direction of the punches are connected to a rack 51 provided on the transmission member and a driven tooth 46 provided on the punch member 40 as follows. Match.

  As shown in FIG. 1 and FIG. 4, the fourth punch member 40d and / or the first limit position LL located at the right limit position LL of the transmission member 50 with respect to the punch members 40a to 40d arranged linearly. The driven teeth 46d of at least one of the punch members 40a (the illustrated fourth punch member 40d) and the rack 51 formed on the transmission member 50 are connected via an intermediate gear 47. Then, the outer diameter of the intermediate gear 47 is set so as to form a predetermined inter-axis distance Ly between the intermediate gear 47 and the fourth punch member 40d.

  With this configuration, the effective length Lx of the base frame 30, the distance Ls1 between the first punch member 40a and the second punch member 40b, the distance Ls2 between the second and third punch members 40b and 40c, and the third 3- The relationship with the interval Ls3 between the fourth punch members 40c and 40d is [Lx ≧ Ls1 + Ls2 + Ls3]. At this time, assuming that the one-way movement amount of the transmission member 50 is St and the inter-axis distance of the intermediate gear 47 is Ly, the operation region Lz of the transmission member 50 is [Lz = Lx + 2St−Ly].

  Therefore, as shown in FIG. 8, when a plurality of punch members 101 are directly gear-coupled to a conventional rack 102 without using an intermediate gear, the operation region Lz of the rack 102 is [Lz = Lx + 2St]. The operating region of the transmission member 50 can be shortened by the length Ly.

Plate member that reciprocates with a predetermined stroke St as described above (transmission member; 50) The rack 51 (drive teeth) is formed, the driven gear plurality of punch members 40 in the rack 51, which is formed in each 46 is engaged. As shown in FIG. 1, a drive motor M is connected to one end of the transmission member 50 (left end in FIG. 1). Further, the punch member 40 d located at the other end (right end in FIG. 1) of the transmission member 50 is engaged (engaged) with the rack 51 via the intermediate gear 47. The engagement relationship between the drive motor M and the transmission member 50 will be described later with reference to FIG.

In the embodiment shown in FIG. 1, the plurality of punch members 40 a to 40 d are engaged with the first punch members 40 a, 40 b, and 40 c that are directly engaged with the rack 51, and the rack 51 and the intermediate gear 47. And a second punch member 40d. At this time, the first punch member 40a, 40b, and vertical position of the driven gear 46 and a cam 45 provided along the drilling direction in 40c, a driven gear 46 provided along the drilling direction in the second punch member The vertical positions of the cams are arranged differently.

In the present invention, the punch member 40d at the right limit position RL and the rack 51 are connected by the intermediate gear 47. However, the punch member 40a at the left limit position LL and the rack 51 are connected by the intermediate gear 47. the same effect can be obtained even if. In this case, it is necessary to set the intermediate gear 47 on the rack center side.

"Position sensor"
The transmission member 50 is provided with a position sensor for detecting its position. This will be described with reference to FIG. As shown in FIG. 5A, the transmission member 50 is provided with a first sensor flag 55 (55a, 55b, 55c) and a second sensor flag 56, and the first sensor flags 55a to 55c are used as the first position sensor. Sp1 detects the position of the second sensor flag 56 by the second position sensor Sp2 and the third position sensor Sp3. The position sensors Sp1 to Sp3 will be described later.

  Next, the cam groove 45 of the punch member 40 configured as described above will be described. As described above, the cam groove 45 as shown in FIG. 2B is provided in the cylindrical cam 44 provided in each of the punch members 40a to 40d. The illustrated one has a structure in which punching is performed on the sheet S by selecting either 2 holes or 4 holes. In this relationship, cam grooves 45a and 45d having the same shape are formed on the outer circumferences of the cylindrical cams 44 of the first punch member 40a and the fourth punch member 40d on the outer circumferences of the cylindrical cams 44 of the second punch member 40b and the third punch member 40c. Are formed with cam grooves 45b and 45c having the same shape.

  Each of the cam grooves 45a to 45d is provided with an inclined cam surface 45θ inclined by a predetermined angle (θ) with respect to the drilling direction (vertical direction in FIG. 2B), and the first and fourth cam grooves 45a and 45d have In one place, the second and third cam grooves 45b and 45c are formed with inclined cam surfaces 45θ at two places (see FIG. 2B). The inclined cam surfaces 45θ of the first and fourth cam grooves 45a and 45d and one inclined cam surface 45θ of the second and third cam grooves 45b and 45c are respectively at the same angular position (first angular position) of the cylindrical cam 44. 4 holes are made in the sheet S at the first angular position.

  Further, the other inclined cam surfaces 45θ of the second and third cam grooves 45b and 45c are formed at the same angular position at an angular position (second angular position) different from the first angular position of the cylindrical cam 44. In the position, 2 holes are made in the sheet. At the second angular position, the first and fourth cam grooves 45 a and 45 d are formed as linear grooves that are horizontal in the outer circumferential direction of the cylindrical cam 44. Therefore, as described above, the first to fourth cam grooves 45a to 45d engaged with the cam follower 33 fixed to the upper frame 30 have the first to fourth punch members 40a to 40d moved to the sheet S at the first angular position. The second and third punch members 40b and 40c punch two holes in the sheet S at the second angular position.

The cylindrical cams 44 are attached to the punch members 40a to 40d so as to have a phase difference by a predetermined angle, and the punching timings of the punch members 40a to 40d are varied when simultaneously punching holes. That is, as shown in FIG. 1, when four holes are formed, each punch member 40a to 40d has a time difference (cam groove) in the order of the first punch member 40a, the second punch member 40b, the third punch member 40c, and the fourth punch member 40d. The timing of drilling is shifted with the difference of the deviation. Similarly, when the two holes are formed, the second punch member 40b and the third punch member 40c are sequentially provided with a phase difference. Such a phase difference is generated by shifting the positions of the cam grooves 45a to 45d by a predetermined angle when the driven teeth 46 of the punch members 40a to 40d are engaged with the rack 51 of the transmission member 50 at the time of assembling the apparatus. Make the opening timing different.

  In the above description, the punch holes are made into two holes and four holes. However, by changing the arrangement interval and arrangement number of the punch members 40 described above, three holes are punched, or four holes are formed above and below the sheet by changing the central interval. Of course, it is also possible to perforate. In the apparatus shown in FIG. 1, the cylindrical cam 44 has a cam groove 45 formed on the entire outer periphery thereof, but this is formed only on the inclined cam surface 45θ, and the punch member 40 is reciprocated by this cam portion. There may be. Furthermore, in the present invention, the case where the end face shape of the perforating blade 41 is cut into a U shape or a V shape has been shown, but this may be a semicircular shape.

  Next, the operation control of the punch member 40 will be described. First, the drilling operation of the first to fourth punch members 40a to 40d will be described with reference to FIG. This figure shows a cam diagram in which the above-described cylindrical cam 44 is developed in a plane. The second third punch members 45b and 45c are formed with two inclined cam surfaces 45θ, and the first and fourth punch members 40a, One inclined cam surface 45θ is formed on 40d.

  And all the punch members 45a-45d are formed with the inclined cam surface θ at the same location (exactly, with a slight phase difference). Therefore, home positions HP1, HP2, and HP3 are set at the positions illustrated in FIG. 2B, and when the transmission member 50 is reciprocated between the first home position HP1 and the second home position HP2, the punched sheet has four holes. When the transmission member 50 is reciprocated between the second home position HP2 and the third home position HP3, the perforated sheet is perforated with two holes.

  Therefore, the transmission member 50 is provided with a first sensor flag 55 and a second sensor flag 56 as shown in FIG. 6, and the first sensor flag 55 is provided with three flags 55a, 55b and 55c. One flag is provided for the two-sensor lug 56. A first position sensor Sp1 that detects the first sensor flag 55 and two position sensors (second position sensor Sp2 and third position sensor Sp3) that detect the second sensor flag 56 are provided. The drive motor M is provided with an encoder 54 and an encode sensor Se.

  The first sensor flag 55 is disposed at a position where the first, second, and third home positions of the transmission member 50 are detected. The second sensor flag 56 is disposed on the transmission member 50 at a position where the state of the punching operation is detected. The detection states of these sensors will be described with reference to FIG. In the state of FIG. 5A, Sp1 “ON”, Sp2 “OFF”, and Sp3 “ON” are detected, and the state where the transmission member 50 is located at the left limit position LL is detected. The home position HP1 (operation start & end position) when the four holes are drilled is detected in the detection state of this sensor.

  That is, when the drive motor M moves to the left side of the transmission member 50 in the figure, the left limit position LL is detected by this position detection and the drive motor M is stopped. When the transmission member 50 is moving to the right side of the figure, this position detection detects the home position HP1 (operation start / end position) when the four holes are drilled, and the rotation amount of the drive motor M is determined based on this position. Control.

  Next, in the state of FIG. 5B, Sp1 “OFF”, Sp2 “ON”, and Sp3 “ON” are detected, and the four-hole drilling operation position is detected. That is, in this state, the punch members 40a to 40d perform a punching operation on the sheet S. In the state shown in FIG. 7C, Sp1 “ON”, Sp2 “ON”, and Sp3 “OFF” are detected, and the second home position HP2 is detected. In this state, the four-hole drilling operation is finished. When the transmission member 50 is moved to the left side of FIG. 7 with reference to this position, the operation moves to the 4-hole drilling operation, and when it moves to the right side of the drawing, the operation moves to the 2-hole drilling operation.

  Next, when Sp1 “OFF”, Sp2 “OFF”, and Sp3 “OFF” in FIG. In this state, the punch members 40b and 40c perform a punching operation on the sheet S. Then, when Sp1 “ON”, Sp2 “OFF”, and Sp3 “OFF” in FIG. 5E, the third home position HP3 (end position of the two-hole drilling operation) is detected. That is, when two holes are drilled, the drive motor M is stopped by detecting this state, and then the rotation is reversed.

  As described above, 4-hole drilling is performed in the process of reciprocating the slide plate 50 between the first and second home positions, and 2 holes in the process of reciprocating the slide member 50 between the second and third home positions. Drilling is performed. The encoder 54 provided in the drive motor M detects a state in which the punch member stops abnormally due to the rotation direction of the rotation shaft of the drive motor M and a jam. Control of the drive motor M will be described later.

[Description of Embodiment of Post-Processing Apparatus]
Next, the configuration of the post-processing apparatus in the image forming apparatus according to the present invention will be described with reference to FIG. The image forming system shown in FIG. 8 includes an image forming apparatus B that sequentially prints sheets, and a post-processing apparatus C that is attached downstream of the image forming apparatus B. The sheet formed by the image forming apparatus B is subjected to punching processing on the printed sheet by the post-processing apparatus C. First, the image forming apparatus B can employ various structures such as a copying machine, a printer, and a printing machine, but the illustrated one shows an electrostatic printing apparatus.

  In the image forming apparatus B, a paper feed unit 2, a printing unit 3, a paper discharge unit 4, and a control unit (not shown) are built in a casing 1. A plurality of cassettes 5 corresponding to the sheet size are prepared in the sheet feeding unit 2, and a sheet having a size designated by the control unit is fed out to the sheet feeding path 6. A registration roller 7 is provided in the sheet feeding path 6 and the sheet is fed to the downstream printing unit 3 at a predetermined timing after the leading edges of the sheets are aligned.

  An electrostatic drum 10 is provided in the printing unit 3, and a print head 9, a developing device 11, a transfer charger 12, and the like are disposed around the drum 10. The print head 9 is composed of, for example, a laser light emitter, and forms an electrostatic latent image on the electrostatic drum 10. A toner ink is attached to the latent image by the developing device 11 and printed on a sheet by the transfer charger 12. . This print sheet is fixed by the fixing device 13 and carried out to the paper discharge path 17.

  The paper discharge unit 4 is provided with a paper discharge port 14 and a paper discharge roller 15 formed in the casing 1. Reference numeral 16 denotes a circulation path. The print sheet from the paper discharge path 17 is turned upside down on the switchback path and then sent to the registration roller 7 again to form an image on the back surface of the print sheet. In this way, the print sheet on which one side or both sides are formed is carried out from the paper discharge port 14 by the paper discharge roller 15.

  In the figure, reference numeral 20 denotes a scanner unit which optically reads a document image to be printed by the print head 9. As is generally known, the platen 23 on which a document sheet is placed and set, a carriage 21 that scans a document image along the platen 23, and an optical device that photoelectrically converts an optical image from the carriage 21. It comprises a reading means (for example, a CCD device) 22. In the illustrated example, a document feeder 25 for automatically feeding a document sheet to the platen is provided on the platen 23.

  Therefore, a post-processing device C is connected to the paper discharge port 14 of the image forming apparatus B. The post-processing apparatus C includes a sheet conveyance path 26, a punch unit A disposed in the conveyance path 26, and a paper discharge stacker 28. The sheet conveying path 26 is provided with an aligning means 26a on the upstream side of the punch unit A, and aligns the sheet trailing edge. In addition, a forward / reverse roller 26b is disposed in the transport path 26, and a sheet from the carry-in entrance 26c is abutted and aligned with the aligning means 26a. . Si shown in the figure is a sheet detection sensor. The punch unit A is constituted by the apparatus shown in FIG.

  The post-processing apparatus C configured as described above receives the printed sheet from the image forming apparatus B from the carry-in entrance 26c, detects the sheet rear end by the sheet detection sensor Si, and the timing at which the sheet rear end passes through the aligning unit 26a. Thus, the forward / reverse rotation roller 26b is reversely rotated (counterclockwise in the figure). Then, the sheet is switched back and the rear end of the sheet is abutted and aligned with the aligning means 26a. After this alignment, the forward / reverse roller 26b stops and holds the sheet in that position.

  In this state, the punch unit A drives the drive motor M to execute the above-described punching operation. After execution of the punching operation, the forward / reverse rotation roller 26b is rotated in the clockwise direction in the figure by the end signal from the position sensor S1, and the punched sheet is carried out to the discharge stacker 28. In addition, although not shown, a staple unit, a stamp unit, and the like are incorporated in the post-processing apparatus C according to apparatus specifications.

A Unit 30 Upper frame (base frame)
31 Upper guide 32 Lower guide 33 Cam follower 35 Lower frame (base frame)
40 Punch member (40a-40d)
41 Drilling blade 44 Cylindrical cam 45 Cam groove 46 Driven tooth 47 Intermediate gear 50 Transmission member (slide plate)
51 Drive teeth (rack)
54 Encoder M Drive motor RL Right limit position LL Left limit position St Predetermined stroke

Claims (7)

A base frame,
A plurality of punch members disposed on the base frame;
Drive means for reciprocating each punch member in the perforating direction;
With
The plurality of punch members are arranged on a substantially straight line at a predetermined interval on the base frame,
The driving means includes
A drive motor;
A transmission member that reciprocates with a predetermined stroke in a direction intersecting the drilling direction by rotation of the drive motor;
Drive teeth formed on the transmission member;
Driven teeth formed on each punch member;
Consists of
The drive teeth and the driven teeth mesh with each other so as to move up and down in the perforating direction while rotating the punch members, and the punch members positioned on at least one of the transmission members include the driven teeth and the transmission members A paper sheet punching device, wherein the drive teeth are connected to each other through an intermediate gear having a predetermined outer diameter. The transmission member is constituted by a slide plate which reciprocates with a predetermined stroke to said base frame, said driving tooth, according to claim 1, characterized in that it is constituted by a rack formed on said slide plate Paper punching device. The drive motor is disposed at a position that engages with one end of the rack in the reciprocating direction formed on the slide plate, and a punch member that engages with the other end of the rack in the reciprocating direction is interposed via the intermediate gear. The paper sheet punching device according to claim 2 , wherein the paper punching device is engaged with each other. Between the base frame and the plurality of punch members, a cam for converting the rotation of the punch member into a movement in a punching direction is provided on one side, and a cam follower for engaging with the cam is provided on the other side. The paper sheet punching device according to any one of claims 1 to 3 . The plurality of punch members include a first punch member whose driven teeth are directly engaged with the rack, and a second punch member engaged with the rack via an intermediate gear,
The plurality of punch members are provided with cams for converting the rotation of the punch members into movements in a punching direction, and the base frame is provided with a cam follower that engages with the cams.
In the plurality of punch members, driven teeth and cams are arranged vertically along the drilling direction, and the vertical positions of the driven teeth and the cams are different between the first punch member and the second punch member. The paper sheet punching device according to claim 2, wherein   The transmission member is constituted by a rack, and the punch member located at at least one of the left limit position and the right limit position of the transmission member is connected to the intermediate gear with the driven tooth. The paper sheet punching device according to claim 1, wherein the paper punching device is disposed outside the meshing region.   2. The paper according to claim 1, wherein the plurality of punch members include four punch members and are connected to the driving unit so as to selectively execute 2-hole drilling and 4-hole drilling. Leaf punching device.

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