JP2012056040A - Hole-punching pin, hole-punching device, sheet processing device, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hole-punching pin capable of reducing a load which occurs when blade top parts bite into paper and a load which occurs when a blade valley part cuts through the paper while avoiding the occurrence of imperfect cut such as break-off or insufficient cut such as burring, and to provide a hole-punching device, a paper processing device and an image forming device.SOLUTION: In the side view of a blade edge section 204 having the blade valley part 203 located between the opposed blade top parts 202, a blade edge line 205 extending from the blade top parts 202 toward the blade valley portion 203 is formed by combining first circular arcs 210 and second circular arcs 220 on the sides of the blade top parts 202 with a third circular arc 230. Relative to the blade edge line 205, the centers of the first circular arcs 210 and the third circular arc 230 are located on an axial line e of a body section 201 and the centers of the second circular arcs 220 are located on mutually opposite sides to form S-shaped curves 206. The S-shaped curves 206 are formed symmetrical to the axial line e of the body section 201. The S-shaped curves 206 symmetrical with respect to the axial line e continue the third circular arc 230 in common to form the blade valley part 203.

Description

  The present invention relates to a punch pin, a punch device, a paper processing device, and an image forming apparatus.

  In a punching device that punches a sheet by reciprocating the die pin of a punching pin using a DC motor or the like as a driving source, the thicker the sheet or the greater the number of sheets, the greater the load when punching the sheet. . In order to cope with a large load, it is necessary to use a DC motor or the like that can obtain a large torque as a drive source. It is not preferable. For this reason, for example, in Patent Document 1, the cutting edge portion of the punch is formed with a two-stage shear angle, and the sheet material is sharply perforated with a small outer shear angle, thereby reducing the load during perforation and motor torque. A technique for lowering is disclosed. Further, for example, Patent Document 2 discloses a technique for shifting the height direction position of the blade pin top portion of the punch pin to shift the timing at which the blade top portion bites into the sheet material, thereby reducing the load during drilling.

International Publication No. 2006/038291 Pamphlet JP-A-10-109299

  By the way, the load generated when punching the paper becomes a large load on the drive source. The load generated when the top of the punch pin bites into the paper and the trough of the punch pin cut out the paper. It is a generated load. However, in each of the above-described conventional techniques, only a reduction in the load generated when the top of the punch pin bites into the paper is considered, and the load generated when the blade trough of the punch pin cuts the paper is reduced. Is not considered.

  Also, as shown in FIG. 22, when punching a folded sheet depending on the thickness and number of sheets, the tip of the edge line of the edge line of the conventional inverted U-shaped or V-shaped valley edge bite. Later, when the cutting edge line was further cut, the strength of the paper reached the limit before the bottom of the blade valley reached the paper, and one end of the edge of the blade was broken, and the other was broken and lost support. Because it tries to cut off a piece of paper, it may be incompletely cut out.

  The present invention has been made in view of the above circumstances, and can reduce the load generated when the blade top portion bites into the paper and the load generated when the blade valley portion cuts out the paper, and can be broken. It is an object of the present invention to provide a perforation pin, a perforation device, a paper processing device, and an image forming device that do not cause incomplete cutting, burr and uncut portions.

Means for Solving the Problems and Effects of the Invention

  In order to solve the above-mentioned problems, the punch pin of the present invention is a punch pin for punching a paper, and is formed with a blade tip portion that has a blade top portion that cuts into the paper and a blade valley portion that cuts out the paper, and is opposed to the punch pin. In the side view of the cutting edge portion where the cutting edge portion is located between the cutting edge portions, the cutting edge line from the cutting edge portion toward the cutting edge portion is a first arc, a second arc, and a second arc on the cutting edge side. 3 arcs are combined, and the center of the first arc and the third arc is located on the axis side of the main body with respect to the cutting edge line, and the center of the second arc is located on the opposite side. A character-shaped curve is formed, and the S-shaped curve is symmetrical with respect to the axis of the main body, and the S-shaped curve that is symmetric with respect to the axis is continuous with the third arc in common. And the said blade trough part is formed, It is characterized by the above-mentioned.

  In this way, it is possible to reduce the load generated when the blade top portion bites into the paper and the load generated when the blade valley portion cuts out the paper. Specifically, even after biting into the paper at the top of the blade, it is cut out without being broken by the curves of the first arc and the second arc, and even if a middle break occurs in the remaining portion, the third arc causes the valley portion Can be cut out on the entire surface. Therefore, there is no incomplete drilling such as tearing or burrs, and a clean drill hole can be formed and drilled smoothly. There is an effect that drilling can be performed without applying a film.

  In the present invention, the S-shaped curve symmetrical to the axis shares the first arc.

  In this way, the cutting edge is formed symmetrically with respect to the axis of the main body, so that it can be cut evenly from both sides, and a well-formed perforation can be made without generating uncut residue on one side. Paper can be cut out with holes.

  In the present invention, at least one of the first arc, the second arc, and the third arc is an elliptical shape, and the elliptical shape has a diameter of an arc in a direction perpendicular to the axis of the main body. It is said to be big.

  In this way, for example, if the first arc and the second arc are elliptical, the cutting edge is formed at a lower position than the main body, and the depth at which the cutting edge bites into the paper can be reduced. . Therefore, the sheet is not easily folded and can be punched in a short time, so that the load on the driving source can be reduced. Further, for example, if the third arc is formed in an elliptical shape, the blade valley portion is formed at a lower position with respect to the main body portion, and even if the paper is bent halfway, the paper is applied to the entire surface of the blade valley portion before being broken. Since it becomes easy to touch, more reliable drilling becomes possible.

  According to another aspect of the present invention, there is provided a drilling device including a drilling mechanism having the drilling pin, a drive source for generating power for driving the drilling mechanism, and transmitting the power to the drilling mechanism, Transmission means for reciprocating the pin with respect to the die hole.

  In addition, a paper processing apparatus according to another aspect of the present invention includes the punching device, and transports the paper punched by the punching device along a predetermined internal path and discharges the paper to the outside. And

  An image forming apparatus according to another aspect of the present invention includes the sheet processing device, reads image data from a document, performs predetermined image processing on the read image data, and performs the image processing. An image indicated by the data is printed.

  According to these punching device, paper processing device, and image forming apparatus, it is possible to reduce the load that occurs when the blade top portion of the punching pin bites into the paper and the load that occurs when the blade valley portion cuts out the paper. At the same time, there is an effect that there is no occurrence of incomplete cutting that is torn off, or burrs.

1 is a schematic diagram illustrating an example of a copying system including a punching device according to a first embodiment. The perspective view which shows the example of the guide mechanism with which the punching apparatus of 1st Embodiment is provided. The perspective view which shows the example of the punching mechanism with which the punching apparatus of 1st Embodiment is provided, and a drive mechanism. The enlarged view of the part of the circle | round | yen 4 of the punching mechanism shown in FIG. The enlarged view which looked at the part of the circle | round | yen 5 of the punching mechanism shown in FIG. 3 from the direction of arrow a. The enlarged view at the time of seeing the part of the circle | round | yen 6 of a piercing | drilling mechanism and a drive mechanism shown in FIG. 3 in the state before rotation of a drive gear from the direction of arrow b. The enlarged view which looked at the part of the circle | round | yen 6 of the punching mechanism and drive mechanism which are shown in FIG. The front view of the punch pin of 1st Embodiment. FIG. 9 is a side view of the piercing pin of FIG. 8. FIG. 9 is a plan view of the drill pin of FIG. 8. FIG. 9 is a bottom view of the piercing pin of FIG. 8. FIG. 9 is a perspective view of the piercing pin of FIG. 8. The elements on larger scale which show the blade edge part of FIG. The elements on larger scale which show the example which made the shape of the 1st circular arc, the 2nd circular arc, and the 3rd circular arc of the punch pin of FIG. The elements on larger scale which show the state which the blade top part bite into the paper. The elements on larger scale which show the state which perforates a paper with a 1st circular arc. The elements on larger scale which show the state which punches a paper with a 2nd circular arc. FIG. 9 is a partial enlarged view showing a state in which punching of a sheet is completed by a third arc. The schematic diagram which shows an example of the 2nd paper processing apparatus provided with a punching apparatus. FIG. 3 is a schematic diagram illustrating an example of a copying apparatus including a punching device. FIG. 4 is a schematic diagram illustrating an example of a copying apparatus including a second paper processing apparatus including a punching device. The front view of the perforation pin which has an inverted U-shaped and V-shaped trough edge part which shows an example of a prior art.

  Hereinafter, embodiments of a punch pin, a punch device, a paper processing device, and an image forming apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, a copying apparatus is described as an example of the image forming apparatus. However, the present invention is not limited to this. For example, in addition to the copying function, at least one of a printer function, a scanner function, and a facsimile function is used. It may be a multifunction peripheral (MFP) having the above functions.

(First embodiment)
First, an outline of the image forming apparatus copying system 100 including the punching apparatus 110 according to the first embodiment will be described.

  FIG. 1 is a schematic diagram illustrating an example of a copying system 100 including a punching device 110 according to the first embodiment. As shown in FIG. 1, the copying system 100 includes a copying apparatus 101, a first sheet processing apparatus 102 including a punching apparatus 110, and a second sheet processing apparatus 103.

  The copying apparatus 101 copies an image printed on a document onto a sheet. Specifically, the copying apparatus 101 reads image data from a document, performs predetermined image processing on the read image data, prints an image indicated by the image data subjected to the image processing, and prints the image. Eject the paper out of the device.

  The first sheet processing apparatus 102 is disposed on the side of the copying apparatus 101 on the sheet discharge side, and transfers the sheet discharged from the copying apparatus 101 through a predetermined transfer path (not shown) inside the apparatus. A punching device 110 is provided in the middle of the transport path. When the first paper processing device 102 transports the paper to the position where the punching device 110 is provided, the transport is temporarily stopped and the punching device 110 performs the punching. . Then, the first paper processing apparatus 102 resumes the conveyance of the paper when the punching of the paper is completed, and the punched paper is discharged out of the apparatus.

  The second paper processing device 103 is disposed on the side of the first paper processing device 102 on the paper discharge side, and conveys the paper discharged from the first paper processing device 102 into the inside of the device. Then, the second paper processing device 103 performs collation processing, binding processing (staple processing), and the like on the bundle of paper stored in the device, and discharges the paper to the paper tray 104.

  Next, the configuration of the perforating apparatus 110 according to the first embodiment will be described.

  As shown in FIG. 2, the guide mechanism 120 includes an upper guide frame 122, a lower guide frame 124, a die frame 126, a right side plate 128, and a left side plate 130.

  The upper guide frame 122, the lower guide frame 124, and the die frame 126 are formed with die holes 122A and 122B, die holes 124A and 124B, and die holes 126A and 126B at the same interval. It is fixed so as to be sandwiched between the plates 130. The die holes 122A, 124A, and 126A are located side by side in the vertical direction, and guide the reciprocating movement of the drill pin 200A in the vertical direction. Similarly, the die holes 122B, 124B, and 126B are also arranged in the vertical direction, and guide the reciprocating movement of the drill pin 200B in the vertical direction. The diameters of the die holes 122A, 124A, and 126A all correspond to the diameter of the drilling pin 200A, and the diameters of the die holes 122B, 124B, and 126B all correspond to the diameter of the drilling pin 200B. Yes.

  As shown in FIGS. 3 to 5, the drilling mechanism 140 includes a slide arm 142, support pins 144 </ b> A and 144 </ b> B, links 146 </ b> A and 146 </ b> B, and drill pins 200 </ b> A and 200 </ b> B.

  The link 146B holds the piercing pin 200B via the support pin 144B, and shaft-shaped fulcrums are provided at both ends in the holding direction of the piercing pin 200B. Note that both fulcrums provided on the drill pin 200B are rotatably supported by the right side plate 128 and the left side plate 130 of the guide mechanism 120, and one of the fulcrum points is connected to the connecting portion of the slide arm 142. . Similarly, the link 146A holds the piercing pin 200A via the support pin 144A, and shaft-shaped fulcrums are provided at both ends in the holding direction of the piercing pin 200A. Note that both fulcrums provided on the drill pin 200 </ b> A are rotatably supported by the right side plate 128 and the left side plate 130 of the guide mechanism 120, and one of the fulcrums is connected to the connecting portion of the slide arm 142. .

  As shown in FIG. 3, the drive mechanism 150 includes a drive motor 152, a drive motor gear 154, a reduction gear train 156, drive gears 158A and 158B, a sensor filler 160, a home position sensor 162, and a pulse count sensor 164. Are provided.

  The drive motor 152 is a drive source that generates power for driving the drilling mechanism 140 and can be realized by, for example, a DC brush motor. The driving force (rotational driving force) generated by the drive motor 152 is transmitted to the drive gears 158A and 158B through the reduction gear train 156 coupled to the drive motor gear 154. The sensor filler 160 integrated with or integrally attached to the drive gear 158A and the home position sensor 162 detect the rotation speed (rotation amount) of the drive gear 158B required for punching paper. , Notify a control unit (not shown). In addition, the pulse count sensor 164 detects the number of pulses of the drive motor 152, and the control unit described above controls the drive motor 152 so that the rotation speed is appropriate according to the detected number of pulses.

  As shown in FIG. 6, the convex portion 159 provided on the drive gear 158 </ b> B of the drive mechanism 150 is movably connected to a D-shaped groove 143 formed on the slide arm 142 of the punching mechanism 140. When the driving force of the driving motor 152 is transmitted from the driving gears 158A to 158B and the driving gear 158B rotates counterclockwise (in the direction of arrow c in FIG. 6), the slide arm 142 reciprocates in the longitudinal direction. Specifically, the convex portion 159 of the drive gear 158B pushes the linear portion of the groove 143 of the slide arm 142, so that the slide arm 142 moves in the direction of the arrow d as shown in FIG. Return to the state of 6. Then, the reciprocating movement of the slide arm 142 in the longitudinal direction causes the links 146A and 146B to reciprocate and reciprocate the perforating pins 200A and 200B, respectively. As a result, two holes are punched in the paper.

  As described above, in the present embodiment, the case of drilling two holes has been described as an example, but the number of holes to be drilled is not limited to this. For example, it is possible to drill a desired number of holes by providing a drilling device with die holes, drilling pins, support pins, and links according to the desired number of holes.

  Next, the shape of the punch pin 200A of the first embodiment will be described. Note that the shape of the perforation pin 200B is the same as the shape of the perforation pin 200A, and a description thereof will be omitted. 8 to 12 respectively show a front view, a side view, a plan view, a bottom view, and a perspective view of the drill pin 200A.

  As shown in FIGS. 8 to 12, the perforating pin 200 </ b> A has a cylindrical shape, and a blade edge portion 204 having a blade top portion 202 that cuts into the paper and a blade valley portion 203 that cuts out the paper is formed at the lower end of the main body portion 201. Is formed. As the material of the perforated pin 200A, a non-metallic inorganic material such as ceramic having a light weight and high hardness is used. As a result, the weight of the perforation pin 200A is reduced, and the load on the drive motor 152 can be reduced. Further, the blade edge portion 204 is subjected to a film treatment such as a TiN treatment. As a result, the wear resistance and durability of the cutting edge portion 204 can be improved, and the deterioration of the cutting edge portion 204 of the punching pin 200A in the case of punching various types of paper or thick paper can be dealt with.

  As shown in FIG. 13, in the side view of the blade edge portion 204 where the blade valley portion 203 is located between the opposite blade edge portions 202, the blade edge line 205 from the blade edge portion 202 toward the blade valley portion 203 is on the blade edge portion 202 side. The first arc 210, the second arc 220, and the third arc 230 are combined. Then, the center of the first arc 210 and the third arc 230 is located on the axis e side of the main body 201 with respect to the cutting edge line 205 obliquely extending from the blade top portion 202 to the blade valley portion 203, and the second arc The S-shaped curve 206 is formed by the center of 220 being located on the opposite side.

  Further, the S-shaped curve 206 is symmetric with respect to the axis e of the main body 201, and the S-shaped curve 206 that is symmetric with respect to the axis e is continuously shared by the third arc 230. 203 is formed.

  More specifically, since the S-shaped curve 206 is symmetric about the axis e of the main body 201, an inverted S-shaped curve 207 is formed on the right side of the axis e. The S-shaped curve 206 and its inverse S-shaped curve 207 have the first arc 210 in common, and further, the third arc 230 smoothly continues in the center to form the blade valley 203.

  The first arc 210, the second arc 220, and the third arc 230 described above are formed by a first circle 211, a second circle 221, and a third circle 231 having these arcs, respectively. The first circle 211, the second circle 221, and the third circle 231 have centers 212, 222, and 232, respectively.

  The center 212 of the first circle 211 having the first arc 210 is located on the axis e of the main body 201 and is located on the lower end side of the main body 201 with respect to the blade edge portion 204. On the other hand, the center 222 of the second circle 221 having the second arc 220 is located on the upper end side of the main body 201 with respect to the cutting edge portion 204, and the two second arcs 220 are relative to the axis e of the main body 201. Located symmetrically.

  The center 232 of the third circle 231 having the third arc 230 is located on the axis e of the main body 201 and is located on the lower end side of the main body 201 with respect to the blade edge portion 204. It can be said that the center 232 of the third circle 231 is located between the center 212 of the first circle 211 and the center 222 of the second circle 221.

  Further, at least one of the first arc 210, the second arc 220, and the third arc 230 has a different radius of curvature depending on the position of the center of the arc. In this embodiment, in these three arcs, The radius of curvature of the third arc 230 is the smallest, followed by the radius of curvature of the first arc 210 and the second arc 220 being the largest. Therefore, since the radius of curvature of the third arc 230 is the smallest, the bottom of the blade valley portion 203 becomes narrow, and the load on the drive motor 152 when punching out the paper can be reduced.

  As described above, according to the perforated pin 200A of the first embodiment, the blade top portion 202 can be sharpened, and the load generated when the blade top portion 202 bites into the paper and the blade valley portion are generated when the paper is cut out. Load to be reduced. Thereby, the drive motor 152 can be reduced in size (a small drive motor is employed), and the drilling device 110 can be reduced in size, reduced in current consumption, reduced in noise, and reduced in cost.

  Further, the blade valley portion 203 formed by a gentle curve by the third arc is continuous with the first arc 210 and the second arc 220, so that at the end of the blade valley portion 203 at the time of drilling, It is possible to cut out the end portion of the middle-folded portion and cut out the middle-folded central portion at the bottom of the blade valley portion 203. Therefore, the cutout in an incomplete state in which the sheet is torn off at the end of the blade valley portion 203 is eliminated. Note that specific operation modes and effects at the time of punching paper will be described in detail later.

(Second Embodiment)
Next, in the second embodiment, the shape of a drill pin having a circular arc whose cutting edge is an ellipse will be described. In the following description, only the shape of the perforation pin, which is the difference from the first embodiment, will be described, and the description of the other parts will be omitted because they are common.

  As shown in FIG. 14, the first arc 310, the second arc 320, and the third arc 330 of the drill pin 300 </ b> A are elliptical shapes having a major axis and a minor axis, and the elliptical shape is the axis of the main body 301. The diameter of the arc in the direction orthogonal to e can be large.

  More specifically, in the side view, the cutting edge line 305 from the blade top portion 302 toward the blade valley portion 303 has the same elliptical first arc 310 on the blade top portion 302 side as that of the second elliptic arc 320 having the same elliptical shape. It is formed by combining an elliptical third arc 330. The center of the first arc 310 and the third arc 330 is located on the axis e side of the main body 301 with respect to the cutting edge line 305, and the center of the second arc 320 is located on the opposite side. A letter-shaped curve 306 and an inverted S-shaped curve 307 are formed.

  Further, the S-shaped curve 306 is symmetrical with respect to the axis e of the main body 301, and the S-shaped curve 306 and the inverse S-shaped curve 307 that are symmetric with respect to the axis e share the third arc 330. As a result, the blade valley portion 303 is formed smoothly and continuously.

  Since the positional relationship and the radius of curvature of each arc are the same as those in the first embodiment, description thereof is omitted.

  According to the drilling pin 300A according to the second embodiment, the first arc 310, the second arc 320, and the third arc 330 are elliptical, and the elliptical shape is orthogonal to the axis e of the main body 301. Since the diameter of the arc in the direction to be moved is large, the position of the blade edge portion 304 is formed lower on the lower end side of the main body 301 than the circular arc of the first embodiment is circular. . Therefore, even with the same punching operation (piercing speed), the paper can be punched quickly in a short time, and since the first arc (blade top 302) is short, the biting into the paper can be reduced, so that tearing or bending occurs. It becomes difficult to do.

  Furthermore, since the third arc 310 is also formed at a low position with respect to the main body 301 due to the elliptical shape, the blade valley portion 303 is also formed low, and can reach the paper more reliably and be perforated.

  Hereinafter, a specific mode when punching a sheet will be described with reference to FIGS. 15 to 18 by taking the punching pin 300A of the second embodiment as an example. 15 shows a state in which the blade top portion 302 bites into the paper P. FIG. 16 shows the first arc 310, FIG. 17 shows the second arc 320, and FIG. 18 shows the third arc 330. The cut-out state is shown step by step.

  As shown in FIG. 15, at the time of punching, when the punching pin 300 </ b> A starts the punching operation from above to below, the sharp blade tip 302 bites into the paper P and is a part of the punching hole 308 in the paper P. A first cut portion 308a is formed.

  After that, as shown in FIG. 16, the paper P is cut in an arc shape by a first arc 310 that obliquely continues from the blade top portion 302 toward the blade valley portion 303. As a result, a second cut 308b larger than the first cut 308a is formed. In addition, since the first arc 310 is the sharpest curve among the cutting edge lines 305, the cutting edge portion 304 can easily bite into the paper, and the cutting can be started by reliably grasping both ends of the perforated hole 308 on the paper. . Further, the sheet P is reliably captured by the depression of the punch pin 300A, and the cutting proceeds.

  Subsequently, as shown in FIG. 17, the paper P is cut along the second arc 320. More specifically, after cutting in by the first arc 310, the paper P is cut out while pushing in the paper P while further biting in by the second arc 320. As a result, a third cut 308c larger than the first cut 308a and the second cut 308b is formed. Since the second arc 320 forms an arc in the opposite direction to the first arc 310, the second arc 320 is more effective when the punching pin 300 </ b> A is pushed down than when the sheet is continuously cut by the first arc 310. The cutting of the paper by the two arcs 320 proceeds slowly, and the paper can be cut out cleanly without being torn.

  Finally, as shown in FIG. 18, the paper P is cut out by the third arc 330, that is, the blade valley portion 303, and the perforated hole 308 is completely formed to complete the perforation. Since the blade valley portion 303 formed by the third arc 330 is formed as a gentle arc, even if the paper P is not stiff and is bent at the time of punching, the paper P does not have the blade valley 303. Can reach the entire bottom. That is, at the end of the blade valley portion 303, the end portion of the folded portion of the sheet can be cut out, and the center portion of the folded portion can be cut out at the bottom portion of the blade valley portion 303. As a result, like the conventional inverted U-shaped or V-shaped valley shown in FIG. 22, the sheet folded at the end of the blade valley is caught, and the sheet is placed at the bottom of the blade valley. There is no risk of tearing before reaching.

  As described above, even if it bites in the sharp first arc 310, it cuts out without breaking with the gentle second arc 320, and even if the remaining part is broken, the third arc 330 cuts out everything in the valley portion. be able to. Therefore, even when the punching operation at a constant speed is performed on the paper, the perforation hole 308 can be formed without incomplete punching, and the motor torque can be smoothly formed at a constant speed. As a result, the hole can be drilled without applying a load to the drive source 152.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, as shown in FIG. 19, the second paper processing device 103 that performs collation processing, binding processing, and the like may include the punching device 110 of each of the above embodiments, or as shown in FIG. The copying apparatus 101 for copying the image printed on the paper may be provided with the punching apparatus 110 of the above embodiment. Further, as shown in FIG. 21, the copying apparatus 101 may include a second sheet processing apparatus 103 including the punching apparatus 110 of the above-described embodiment.

100 Copying System 101 Copying Device (Image Forming Device)
102 First paper processing device (paper processing device)
103 Second paper processing device (paper processing device)
110 Punching device 122A, 122B, 124A, 124B, 126A, 126B Die hole 140 Punching mechanism 152 Drive motor (drive source)
200A, 200B, 300A Drilling pin 201, 301 Main body portion 202, 302 Blade top portion 203, 303 Blade valley portion 204, 304 Blade edge portion 205, 305 Blade line 206, 306 S-shaped curve 207, 307 Reverse S-shaped curve 210, 310 1st circular arc 211 1st circle 212 center (center of 1st circle)
220, 320 2nd circular arc 221 2nd circle 222 center (center of 2nd circle)
230, 330 3rd circular arc 231 3rd circle 232 center (center of 3rd circle)
Axis e
Paper P

Claims (6)

A punch pin for punching paper,
A blade edge portion having a blade top portion that bites into the paper and a blade valley portion that cuts out the paper is formed,
In the side view of the blade edge portion where the blade valley portion is located between the opposed blade top portions,
The cutting edge line from the cutting edge to the cutting edge is a combination of the first arc, the second arc, and the third arc on the cutting edge side, and the first arc and the third arc with respect to the cutting edge line. Is located on the axis side of the main body portion and the center of the second arc is located on the opposite side to form an S-shaped curve, and the S-shaped curve is centered on the axis line of the main body portion. It is symmetrical
The piercing pin according to claim 1, wherein the S-shaped curve symmetric with respect to the axis is continuous with the third arc as a common part, and the edge portion is formed.   The piercing pin according to claim 1, wherein the S-shaped curve symmetric with respect to the axis is common to the first arc.   3. The at least one of the first arc, the second arc, and the third arc has an elliptical shape, and the elliptical shape has a large arc diameter in a direction perpendicular to the axis of the main body portion. Drilling pin as described in.   A drilling mechanism having the drilling pin according to any one of claims 1 to 3, a drive source for generating power for driving the drilling mechanism, and transmitting the power to the drilling mechanism, And a transmission means for reciprocating with respect to the die hole.   A paper processing apparatus comprising the punching device according to claim 4, wherein the paper punched by the punching device is transported along a predetermined internal path and discharged to the outside.   A paper processing apparatus according to claim 5 is provided, image data is read from a document, predetermined image processing is performed on the read image data, and an image indicated by the image data subjected to the image processing is printed. An image forming apparatus.

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