JP2015020217A - Sheet punching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet punching device capable of punching processing in a sheet heated to the comparatively high temperature, and endurable against the high temperature including the environmental temperature.SOLUTION: A sheet punching device comprises an upper frame of the predetermined length adapted to the width directional length of a sheet, a lower frame oppositely arranged at a passing interval of the sheet to the upper frame, a punch member liftably shaft-supported at a predetermined interval by the upper frame, a bearing member arranged in the upper frame and liftably shaft-supporting a plurality of punch members and a blade receiving hole arranged in the lower frame and adapted to the plurality of punch members. The upper-lower frames join both left-right end parts. This joining is executed by at least one rivet pin and a fitting hole, and at least one of the fitting holes formed in the upper-lower frames for fitting this rivet pin is constituted in a long hole shape Xd in the arrangement direction of the punch members, and a length adjusting margin due to a thermal expansion difference between the upper-lower frames is formed between this fitting hole and the rivet pin.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet punching device that punches punch holes in a sheet transported from an image forming apparatus such as a copying machine, a printing machine, or a printer, and takes on a sheet when punching a sheet continuously at high speed. The present invention relates to an improvement of a drilling mechanism in which a frame structure is not distorted by heat.

2. Description of the Related Art Generally, a sheet punching device that punches filing punch holes in sequentially transported sheets (paper sheets) is known as a post-processing device such as an image forming device.
For example, Patent Document 1 discloses a die (blade receiving hole) in which 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 each punch member is fitted to the lower frame. And an apparatus for moving the punch member up and down with a drive motor is disclosed.

  In this document, a transmission mechanism that moves up and down in the drilling direction while rotating a plurality of punch members transmits rotational motion to the punch members by a rack gear or timing belt that is connected to a drive motor and reciprocates at a predetermined stroke. It is disclosed as a mechanism that moves up and down by cam means provided between a member and a base frame.

  In Patent Document 2, 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.

JP 2008-036752 A JP 2001-009791 A

  As described above, an apparatus for punching a predetermined number of punch holes in a sheet by moving a plurality of punch members up and down in the punching direction is already known. For example, Patent Document 1 discloses a mechanism that moves a plurality of punch members up and down by a rack gear mechanism, and Patent Document 2 discloses a mechanism that moves a plurality of punch members up and down by a slide cam mechanism.

  A plurality of punch members are arranged so that two holes can be drilled simultaneously or three holes can be drilled simultaneously. It is arranged.

Thus, for example, the plurality of punch members are supported by the upper frame so as to be able to reciprocate up and down, and the lower frame is disposed to face the lower frame so as to form a gap between the upper frame and the sheet. The same shall apply hereinafter).
For example, in the apparatus of Patent Document 1, the upper frame is made of channel steel and the lower frame is made of flat steel, and the two are connected via a spacer member that forms a passage gap for one sheet.

The connection between the upper frame and the lower frame is required not to be easily separated and to prevent the punch members and the blade receiving holes from being displaced.
If the upper and lower frame members are detached in this way, the basic function of the device is impaired and a device failure occurs. Further, when the punch member and the blade receiving hole are misaligned, the blade edge is damaged and the function is significantly deteriorated.

Therefore, the upper frame and the lower frame must be made of a material that does not easily deform and must be firmly constructed, but the upper and lower frames are connected to each other because a space through which the maximum size sheet can pass is required between the upper and lower frames. Occupies an important machine element.
For example, fixing the upper and lower frames with a fastening fixture such as a screw or a bolt causes a positional shift due to the slack, and it becomes difficult to exchange due to wear of the upper frame or the lower frame by welding or the like.

  Therefore, caulking joining is known as a joining method that has relatively little positional deviation and can be separated (disassembled). This caulking joining method is known as a method of forming fitting holes in upper and lower frames, fitting (inserting) rivet pins, and caulking the tip.

However, the following problems are encountered when connecting the upper and lower frames. For example, a sheet heat-fixed by an image forming apparatus has a high temperature (fixing temperature is around 200 ° C.), so that heat is stored in the upper and lower frames, causing a problem of temperature deformation of the frames.
When the thermal expansion (volume, shape, expansion coefficient) of the upper and lower frames is different, the deformation amount is different, and as a result, one of the upper and lower frames is curved and deformed as shown in FIG.

As shown in FIG. 7A, the upper frame 60 and the lower frame 61 having a predetermined length (L) set according to the seat width are fastened with the right and left rivet pins 62a and 62b. Then, a sheet is inserted (carried in) at a distance d formed between the upper and lower frames, and punching is performed.
At this time, when the sheet temperature is high, heat of the sheet is propagated and accumulated in the upper and lower frames. When this high-temperature sheet is repeatedly guided to the perforation processing section at a high speed, the upper and lower frames are exposed to a high temperature and thermally deformed.

Therefore, when the upper and lower frames are thermally expanded by the same amount at the same temperature, the fixed span (Ls) in the figure expands and contracts by the same amount in the same direction as the upper and lower frames, so that a plurality of shafts supported by the upper frame are supported. The punch member 63 is guaranteed to have a positional relationship that matches the blade receiving hole 61 a formed in the lower frame 61. At this time, there is no problem in the drilling operation due to thermal expansion.
However, when one of the upper and lower frames becomes hotter than the other or a difference in thermal expansion occurs, one of the upper and lower frames may extend from the other. When this phenomenon occurs, the lower frame or the upper frame is distorted.

FIG. 7B shows a case where the lower frame is deformed and deformed, and the blade edge 63 a of the punch member 63 supported by the upper frame is displaced from the blade receiving hole 61 a of the lower frame 61. If the drilling operation is performed in this state, drilling becomes impossible and the cutting edge is lost.
This distorted deformation of the lower frame 61 appears as an unstable phenomenon that occurs when either in the perforation direction or in the downward direction or in the upward direction as illustrated.

The thermal deformation of the upper and lower frames is deformed into a bow shape in the longitudinal direction of the frame as shown in FIG. 7A, and at the same time, the frame is also deformed in the short direction perpendicular to the longitudinal direction (punch arrangement direction).
In the case where the frame shape is configured to have a cross-sectional shape that prevents the frame shape from being deformed in the longitudinal direction, the shape in the longitudinal direction is suppressed, but there is a tendency that the frame shape is greatly distorted in the transverse direction perpendicular thereto.
In such a case, as shown in FIG. 7C, one of the upper and lower frames may be distorted and deformed in the illustrated direction, and the position of the blade edge of the punch member and the blade receiving hole may be out of position.

  If the upper and lower frames are deformed due to thermal expansion in this manner, the positional deviation between the cutting edge of the punch member and the blade receiving hole is caused, and the apparatus cannot be drilled and the apparatus is damaged due to damage to the cutting edge. The failure repair is not easy.

  An object of the present invention is to provide a sheet punching device that can punch a sheet heated to a relatively high temperature and can withstand high temperatures including environmental temperatures.

  In order to achieve the above-mentioned object, the present invention has an upper frame in which a plurality of punch members are linearly arranged and a lower frame having a blade receiving hole that matches the blade edge of each punch member to form a sheet passing gap. When the frames are connected, at least one of both end portions in the arrangement direction of the punch members is crimped with a rivet pin so that either one of the upper and lower frames can move in the longitudinal direction.

  The structure will be described in detail. An apparatus for punching punch holes on a sheet with a plurality of punch members arranged in a linear direction, the upper frame (30) having a predetermined length adapted to the length in the width direction of the sheet; A lower frame (35) disposed opposite to the upper frame with a sheet passing gap therebetween, a punch member (40) axially supported by the upper frame so as to be movable up and down at a predetermined interval, and a plurality of punches disposed on the upper frame. Bearing members (31a, 32a) that support the members so as to be able to move up and down, blade receiving holes (39) that are arranged on the lower frame and fit to a plurality of punch members, and a plurality of punch members (40) as top dead centers Punch drive means (M, G1, 50) that moves up and down between the bottom dead center.

  The upper frame and the lower frame are integrally joined at both left and right ends with a plurality of punch members interposed therebetween, and the right and left ends are joined to at least one rivet pin (37, 38). At least one of the fitting holes formed in the upper frame and the lower frame, which are joined by the holes (30y, 35y) and fit the rivet pin, is formed in an elongated hole shape (Xd) in the arrangement direction of the punch members. The length of the upper and lower frames is adjusted by the difference in thermal expansion and contraction using the elongated hole-shaped fitting hole.

  In the present invention, an upper frame that supports a plurality of punch members so as to move up and down, and a lower frame that is opposed to the frame with a sheet passing gap therebetween are fitted with rivet pins at both ends of the punch row. Since the fitting hole is formed into a long hole that allows one of the upper and lower frames to move in the arrangement direction of the punch members due to a difference in thermal expansion when crimping is stopped with the hole, the following effects can be obtained.

  When an upper frame that supports a plurality of punch members so as to reciprocate at a predetermined interval and a lower frame that has blade receiving holes that match the blade edges of the punch members are integrally connected by forming a sheet passage gap In addition, since both ends in the punch arrangement direction (longitudinal direction) are caulked and fixed with rivet pins and fitting holes, the upper frame is more durable without being displaced as compared with the case where it is connected with a fastening fixture such as a screw. The positional relationship between the cutting edge of the punch member and the blade receiving hole of the lower frame can be ensured.

In addition, the rivet pin has a base hole (flange side) fitted into the long hole fitting hole and the tip is fixed by caulking so that the frame located on the flange side of the upper and lower frames is oblong when it is deformed by thermal expansion. Since it becomes free in the direction, the upper and lower frames are not distorted into a bow shape.
Therefore, even if a high-temperature sheet is repeatedly carried in and out between the upper frames at a high speed, even if a difference in thermal expansion occurs between the upper and lower frames, there is no distortion deformation.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows the whole structure of the sheet | seat punching apparatus concerning this invention. The cross-section of the principal part in the apparatus of FIG. 1 is shown. The joining state of the upper frame in the apparatus of FIG. 1 and a lower frame is shown, (a) is the perspective structure, (b) shows the shape of the fitting hole of the principal part. 2A and 2B are explanatory views of a cross-sectional structure showing a joining state of an upper frame and a lower frame in the apparatus of FIG. 1, wherein FIG. 2A is a cross-sectional structure, and FIG. The structure of the punch member in the apparatus of FIG. 1 is shown, (a) is the perspective structure of a punch member, (b) is an expanded view of the cylindrical cam of a punch member. 2A and 2B are explanatory diagrams of an image forming apparatus including the sheet punching device of FIG. 1, wherein FIG. 2A is an overall configuration thereof, and FIG. 2B is an explanatory diagram of a layout configuration of the punching device. It is explanatory drawing which shows the frame structure of the conventional drilling apparatus, (a) is explanatory drawing of the state which the frame deform | transformed by the thermal expansion difference of an upper frame and a lower frame, (b) is explanatory drawing of the principal part. (C) is explanatory drawing of the state which the frame curved and deform | transformed in the transversal direction.

  The present invention will be described in detail below based on the preferred embodiments shown in the drawings. FIG. 1 is an explanatory view showing the overall configuration of a sheet punching apparatus A according to the present invention, and FIG. 2 is a cross-sectional view of an essential part thereof. FIG. 3 is an explanatory view of a rivet & caulking mechanism for joining the upper frame and the lower frame.

The sheet punching apparatus A shown in FIG. 1 punches holes to be punched in two holes (first group) or four holes (second group) with four punch members 40 (40a, 40b, 40c, 40d; the same applies hereinafter). 1 shows an apparatus, and shows a configuration in which a plurality of punch members are perforated by transmission members (rack, slide cam, etc.) that reciprocate at a predetermined stroke S.
The illustrated one shows a device in which each punch member 40 moves up and down in the drilling direction while rotating from a top dead center (standby position; the same applies hereinafter) to a bottom dead center (a punching position; the same applies below). The configuration will be described below.

As shown in FIG. 1, this apparatus includes an upper frame (base frame) 30 and a lower frame (die plate) 35. The upper frame 30 and the lower frame 35 are opposed to each other with an interval Sd for setting the perforated sheet S (hereinafter simply referred to as “sheet”). The length dimension L is formed larger than the length in the width direction of the sheet.
In the upper frame 30, the first punch member 40a, the second punch member 40b, the third punch member 40c, and the fourth punch member 40d are arranged at predetermined intervals on a straight line at intervals according to a predetermined standard (file hole standard). Has been.
The lower frame 35 is provided with blade receiving holes (die) 39 (39a to 39d) at positions facing the punch members.

Each of the punch members 40a to 40d is formed in a normal cylindrical shape, and a perforating blade 41 is provided at the tip thereof. Since the first to fourth punch members 40a to 40d have the same structure, one of them will be described.
As shown in FIG. 2, the upper frame 30 is composed of a channel member having a U-shaped cross section, and upper and lower guides 31 and 32 facing each other are provided with guide holes 31a and 32a for bearing support of the punch member 40. Yes.

In the punch member 40, the upper shaft portion 42a is fitted and supported in the guide hole 31a, and the lower shaft portion 42b is supported in the guide hole 32a. 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.
Further, the lower frame 35 is provided with a blade receiving hole 39 adapted to the drilling blade 41. The lower frame 35 is formed as a unit by forming a gap Sd in the upper frame 30 and integrally connected by caulking joining described later.

[Joint mechanism of upper frame and lower frame]
The configuration of the upper frame 30 and the lower frame 35 will be described with reference to FIGS.
The upper frame 30 is formed to have a length L in which a plurality of punch members 40 are arranged in a straight line, and the punch members 40 are arranged at intervals according to a predetermined standard.
The illustrated one is composed of four punch members 40a to 40d of a first group (2-hole drilling) and a second group (4-hole drilling), and each punch member is axially supported by the upper frame 30 so as to be reciprocally movable. Yes.

Therefore, the upper frame 30 is made of channel steel having a U-shaped cross section, and the punch members 40 are supported by bearings 31a and 32a (guide holes) so as to be movable up and down.
Further, the lower frame 35 is made of a flat steel material, and is formed with blade receiving holes 39 (39a, 39b, 39c, 39d; the same applies hereinafter) adapted to the cutting edge 41 of the punch member 40. The illustrated upper frame 30 and lower frame 35 are each made of a metal material such as steel (nickel plating) or SUS steel (stainless steel).

Further, a gap Sd allowing passage of one sheet is formed between the upper frame 30 and the lower frame 35, and right and left ends in the longitudinal direction (sheet width direction) as shown in FIG. And it is fastened with the left rivet pin 38. The left and right rivet & caulking joining will be described below.
As shown in FIG. 3, the upper frame 30 has a fitting hole 30y and the lower frame 35 has a fitting hole 35y, and the right rivet pin 37 penetrates both the fitting holes 30y and 35y. . The right rivet pin 37 has a flange 37a formed at the base end with a large diameter portion like the screw head, and a crimp hole 37b provided at the tip end.

  The shaft diameter of the rivet pin 37 (38) is set to Cd. If the rivet pin 37 is fitted in the fitting holes 30y and 35y of the upper and lower frames with such a configuration and the tip portion is crimped, the upper and lower frames 30 and 35 can be joined. The left rivet pin 38 is also formed in the same shape although not shown.

  On the other hand, the fitting hole 30y of the upper frame 30 is formed as a long hole having a dimension Xd (Xd> Cd) in the longitudinal direction of the frame while being able to penetrate the shaft diameter (Cd) of the rivet pin. Further, the fitting hole 35y of the lower frame 35 is formed to have substantially the same diameter as the shaft diameter Cd of the rivet pin.

In FIG. 4, a rivet pin 37 is fitted into the fitting hole 30y of the upper frame 30 and the fitting hole 35y of the lower frame 35 so that the flange 37a is located on the upper frame 30 side and the crimping hole 37b is located on the lower frame 35 side. It is.
The caulking hole 37b is caulked and the upper frame 30 and the lower frame 35 are joined. At this time, the fitting hole 30y of the upper frame 30 is formed to be longer (2 × δ) than the shaft diameter of the rivet pin in the longitudinal direction of the frame, and the frame lateral direction has a diameter substantially equal to the shaft diameter Cd of the rivet pin. It is formed. 36 is a spacer member (bush) that forms a gap Sd between the upper frame 30 and the lower frame 35.

When the upper and lower frames 30 and 35 are swaged with the rivet pins 37 and 38 in such a configuration, the upper frame 30 can be moved in the longitudinal direction of the frame by a length adjustment allowance (± δ) in the illustrated structure.
At this time, when the caulking stop is loose, the upper frame 30 can be easily moved by the adjustment allowance (± δ), and when the caulking stop is tight, the position can be moved by the adjustment allowance (± δ) when a predetermined stress or more is applied. It becomes.
On the other hand, in the illustrated structure, the fitting hole 35y of the lower frame 35 is integrated with the rivet pin 37 (38) with the same diameter.

The upper frame 30 and the lower frame 35 joined in this manner rise to substantially the same temperature as the sheet in both the upper and lower frames when a high temperature sheet is carried in / out at the interval Sd.
For example, when the sheet temperature exceeds 100 ° C., the upper and lower frames expand considerably as compared with room temperature. At this time, if a difference in thermal expansion (volume expansion) between the upper frame 30 and the lower frame 35 occurs, the upper or lower frame that is easily bent is distorted. As a result, the above-described failure phenomenon of FIG. 7 occurs.

However, the fitting hole 30y of the upper frame 30 is formed as a long hole, and the length adjustment allowance (± δ) can be expanded and contracted. Therefore, the length adjustment allowance is set in accordance with the difference in thermal expansion between the upper frame 30 and the lower frame 35 (experimental values are preferred), so that distortion of the upper and lower frames can be prevented.
Further, as shown in FIG. 4 (a), the rivet pins 37 and 38 have their shaft portions (the portions having the shaft diameter Cd) engaged with the elongated holes as shown in FIG. 4 (b) due to the action of caulking force. . Thus, the rivet pins 37 and 38 can be adjusted in length by ± δ in the elongated hole direction of the engagement hole 30y (35y), and at the same time, they are closely fitted and integrated in the orthogonal direction.
As a result, the rivet pins 37 and 38 are securely coupled without causing displacement in the enlarged portion (short direction of the fitting hole), and thermal deformation of the frame is caused by a gap (± in the long direction of the fitting hole). The length is adjusted by δ) and is not distorted.

In the present invention, the upper and lower frames 30 and 35 show a case where the right and left end portions are joined with rivet pins and caulking, and the length adjustment allowance (± δ) for the left and right rivet pins 37 and 38 is shown as the right rivet pin. 37 and the left rivet pin 38 are formed respectively, but this may be provided with a length adjustment allowance at either one of the left and right.
It is also possible to join two or more rivet pins and caulking joints on the left and right ends of the upper and lower frames 30, 35.

The configuration of the punch member 40 will be described with reference to FIG. Each punch member 40a to 40d is integrally provided with a cam means (cylindrical cam 44 in the figure), and a cam groove 45 having an inclined cam surface 45θ is formed on the outer periphery of the cylindrical cam 44.
The cam means constituted by the cylindrical cam 44 converts a rotational motion acting on the punch member 40 into a drilling direction motion as will be described later.

A cam follower member 33 (hereinafter referred to as “cam pin”) that engages with the cam groove 45 is fixed to the upper frame (base frame) 30. As shown in FIG. 2, the cam pin 33 includes a pedestal portion 33a, a guide shaft portion 33b, and a cam engagement portion 33c. The pedestal 33a is fixed to the upper frame 30 with screws or the like.
Therefore, the punch member 40 is supported by the upper frame 30 so as to be slidable up and down, and the cam groove 45 engages with the cam pin 33c, so that the rotational movement of the punch member is converted into the punching direction (vertical direction in the figure).

A passive gear 46 is integrally attached to the punch member 40 (see FIG. 2). The passive gear 46 is engaged with a gear transmission member (rack) 50 and connected to the 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. The cylindrical cam 44 and the passive gear 46 are formed of a synthetic resin such as POM (Duracon resin).
The punching blade 41 of the punch member 40, the cylindrical cam 44, and the passive gear 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 fixed with a fixing screw, 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-shaped cross section, and a front end that contacts the sheet S is formed in an uneven shape. This is because the punching blade 41 penetrating the sheet S is formed in a sharp shape, and at the same time, the shearing force when punching while rotating the punch member 40 is increased.
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.

[Composition of cam means]
The cam groove 45 of the punch member 40 will be described. As described above, the cam groove 45 as shown in FIGS. 5A and 5B 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 that is inclined by a predetermined angle (θ) in the perforating direction (vertical direction in FIG. 5A), 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. 5B).
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 pins 33 fixed to the upper frame 30 have the first to fourth punch members 40a to 40d 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.

Further, each cylindrical cam 44 is attached to the upper frame 30 so as to form a phase difference by a predetermined angle (see FIG. 5B). This is to reduce the punching load by making the punching timings of the punch members 40a to 40d different when simultaneously punching with a plurality of punch members.
As shown in FIG. 5B, when four holes are formed, the time difference (the cam groove displacement difference Δ) is made 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 drilling timing is shifted so as to hold. Similarly, when two holes are formed, a displacement difference Δ is given in the order of the second punch member 40b and the third punch member 40c.

  Such a phase difference Δ shifts the positions of the cam grooves 45a to 45d by a predetermined angle when the passive gear 46 of each punch member 40a to 40d is engaged with the rack gear 51 of the gear transmission member 50 when the apparatus is assembled. Depending on the situation, the drilling timing is made different.

  Although the case where the punch holes are made into 2 holes (first group) and 4 holes (second group) has been described above, 2 holes and 3 holes are punched by changing the arrangement interval and the number of arrangement of the punch members 40 described above. Of course it is possible.

[Configuration of gear transmission member]
As described above, a gear transmission member 50 that reciprocates at a predetermined stroke in the arrangement direction (direction perpendicular to the drilling direction) is provided for a plurality of punch members arranged on a substantially straight line. Rotational motion is transmitted to 40a-40d.

  As shown in FIG. 1, the gear transmission member 50 is configured to reciprocate with a predetermined stroke in an arrangement direction of a plurality of punch members (a direction orthogonal to the drilling direction). A gear transmission member 50 is incorporated in the upper frame 30 so as to be movable in the horizontal direction of the drawing. A rack gear 51 is formed on the gear transmission member 50, and the rack gear 51 meshes with the passive gears 46 of the punch members 40a to 40d.

The gear transmission member 50 is regulated in the vertical direction between the guide shaft portion 33 b of the cam pin 33 and the lower guide 32, and in the front-rear direction thereof is regulated between the back surface of the upper frame 30 and each passive gear 46. (See FIG. 2).
As a result, the passive gear 46 of each punch member 40a to 40d and the rack gear 51 of the gear transmission member 50 are meshed, and each punch member 40a to 40d is rotated by a predetermined angle in accordance with the amount of movement of the gear transmission member 50. .

A drive motor M is connected to the gear transmission member 50 as shown in FIG. A drive motor M is attached to the upper frame 30 with 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 rack gear 51 of the gear transmission member 50.
Therefore, the gear 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.

[Configuration of Image Forming Apparatus]
Next, the configuration of the image forming apparatus B 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 thereof. The sheet punching device A is built in the post-processing device C as a punch unit.

  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.

  A scanner unit 20 shown in the figure 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.
A forward / reverse roller 26b is disposed in the sheet conveyance path 26, and the sheet from the carry-in entrance 26c is abutted and aligned with the aligning means 26a. To do. Si shown in the figure is a sheet detection sensor.

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 an end signal from a position sensor (not shown), and the sheet with punch holes is carried out to the paper 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.

10 Sheet punching device 30 Upper frame (base frame)
30y fitting hole 33 cam follower member (cam pin)
35 Lower frame 35y Fitting hole 36 Spacer member 37 Right rivet pin 37a Flange 37b Caulking hole 38 Left rivet pin 39 Blade receiving hole (die)
40 Punch member 40a First punch member 40b Second punch member 40c Third punch member 40d Fourth punch member 41 Drilling blade 44 Cylindrical cam (cam means)
45 Cam grooves 45a, 45d Cam grooves (first and fourth punch members)
45b, 45c Cam groove (second and third punch members)
46 Passive gear 50 Gear transmission member Xd Longitudinal dimension Cd Short dimension

Claims (5)

An apparatus for punching punch holes on a sheet with a plurality of punch members arranged in a linear direction,
An upper frame of a predetermined length that fits the width direction length of the seat,
A lower frame disposed opposite to the upper frame with a sheet passage gap therebetween;
A punch member axially supported by the upper frame so as to be movable up and down at a predetermined interval;
A bearing member arranged on the upper frame and supporting the plurality of punch members so as to be movable up and down;
A blade receiving hole disposed in the lower frame and adapted to the plurality of punch members;
Punch driving means for raising and lowering the plurality of punch members between a top dead center and a bottom dead center;
With
The upper frame and the lower frame are
While the left and right ends are integrally joined across the plurality of punch members,
The left and right ends are joined by at least one rivet pin and a fitting hole,
At least one of the fitting holes formed in the upper frame or the lower frame for fitting the rivet pin is formed in a long hole shape in the arrangement direction of the punch members,
A sheet punching device, wherein a length adjustment margin due to a thermal expansion / contraction difference between the upper and lower frames is formed between the long hole-shaped fitting hole and the rivet pin. The upper frame and the lower frame are
The left and right ends of the plurality of punch members are joined with rivet pins and fitting holes,
2. The sheet punching device according to claim 1, wherein at least one of the left and right fitting holes is formed in an elongated hole shape in the arrangement direction of the punch members. The rivet pin is
A head portion having a proximal flange;
The caulking part at the tip,
Consists of
A fitting hole of the upper frame or the lower frame that fits the head part is formed in a long hole shape in the arrangement direction of the punch members,
The fitting hole of the other frame to which the caulking part is fitted is formed in a substantially circular shape,
The sheet punching device according to claim 2, wherein a length adjustment margin is formed between the elongated hole shape and the fitted rivet pin by a thermal expansion / contraction difference between the upper and lower frames. The upper frame is made of a channel-shaped steel material,
The lower frame is made of a flat steel material,
The upper frame is formed with a bearing hole for supporting a plurality of punch members so as to be movable up and down,
4. The sheet punching device according to claim 1, wherein a blade receiving hole adapted to the plurality of punch members is formed in the lower frame. 5. In the upper frame, a transmission member such as a rack gear or a slide cam is disposed so as to be able to reciprocate at a predetermined stroke,
The sheet punching device according to any one of claims 1 to 4, wherein the transmission member moves the plurality of punch members up and down by rotation of a drive motor.

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