JP2009113199A - Drive cam for punching apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform punching work with low torque by slowly moving a punch stroke from a home position to a punching position where load is applied. <P>SOLUTION: In a punching apparatus, a cum surface of a drive cum 17 is formed such that the amount of a turning angle of the drive cum 17 required for a punching operation from depressing a punch 13 to punch a recording paper is made larger than the amount of the rotation angle of the drive cum 17 required for a returning operation of restoring to the original position after punching. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a punch processing apparatus that can punch holes in a recording sheet discharged from an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine thereof.

  Various recording paper post-processing apparatuses have been developed that can perform various post-processing operations on each recording paper on which an image is recorded by the image forming apparatus.

  As this recording paper post-processing apparatus, for example, a recording paper post-processing apparatus having a punch processing apparatus described in JP-A-8-25292 is known.

  In this punch device, when the drive cam is rotationally driven, the cam holder is pressed, and the punch attached to the cam holder is pressed to punch holes in the recording paper. Further, when the drive cam rotates, the drive cam acts to push up the cam holder, and the punch returns to the standby position which is the home position.

Japanese Patent Laid-Open No. 08-025292 Japanese Patent Application Laid-Open No. 07-136990 Japanese Patent Laid-Open No. 10-309694

  By the way, in this punch processing apparatus, the rotation angle amount of the drive cam until the punch hole is opened, that is, the pressing angle is set to 180 degrees. In other words, the drive cam is drilled. In order to return to 180 degrees, it is necessary to rotate at 180 degrees.

  Therefore, in this punch processing apparatus, the driving cam is rotated only 180 degrees during drilling with a heavy load, so the punch stroke operation cannot be performed slowly, and a large torque is required during drilling. The inconvenience is caused.

  Accordingly, in view of the above-described circumstances, the present invention has an object to provide a punch processing device that can perform punching with low torque by slowly operating a punch stroke from a home position to a time of punching with a load. To do.

Therefore, the invention described in claim 1 is a punch processing device that punches a punch hole in a recording sheet discharged from the image forming apparatus,
A driving cam that is fixed to a rotating shaft that is rotated by a driving source such as a motor and that is rotated by the rotating operation;
A cam holder that integrally attaches a punch for punching the recording paper and reciprocates by the rotation of the drive cam;
A guide member for guiding the movement of the punch,
The rotational angle of the drive cam required for the punching operation until the recording paper is punched after the punch is pressed down is the rotational angle of the drive cam required for the return operation until the original position after punching is restored. The cam surface of the drive cam is formed so as to be larger than this.

According to a second aspect of the present invention, in the first aspect of the present invention, the cam surface of the drive cam has a forward movement surface that contacts the cam holder until the punch reaches the recording paper from the home position, and the punch is the recording paper. Is composed of a perforation surface that abuts the cam holder until it is perforated, and a surface that abuts the cam holder until the punch reaches the bottom dead center after the perforation operation is completed.
The cam surface of the drive cam is formed so that the punch movement amount per unit rotation angle of the drive cam is minimized as compared with the other cam surfaces.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the drive cam includes a push-down cam that presses the cam holder to press the punch, and a push-up that presses the cam holder to lift the punch. The cam has two types of cams.

  As described above, according to the present invention, the rotation angle amount of the drive cam required for punching operation until the recording sheet is punched by pressing the punch is returned until it returns to the original position after punching. Since the cam surface of the drive cam is formed so as to be larger than the rotational angle of the drive cam required for the operation, a punch processing device capable of drilling with low torque can be provided.

  Further, according to the second aspect of the present invention, among the cam surfaces provided on the drive cam, the perforated surface that comes into contact with the cam holder when the punch perforates the recording paper has a drive cam as compared with the other cam surfaces. Since the punch movement amount per unit rotation angle is the smallest, the punch stroke amount per unit rotation angle of the drive cam at the time of drilling with the most load is also when the drilling surface comes into contact with the cam holder. Since this is smaller than the case where the other cam surface abuts against the cam holder, the punch can be slowly stroked, and a punch capable of drilling with low torque can be provided.

  Furthermore, according to the invention of claim 3, the drive cam has two types of cams: a push-down cam that pushes the cam holder and presses the punch, and a push-up cam that pushes the cam holder and lifts the punch. The amount of rotation angle of the drive cam required for the punching operation until the punching operation is performed until the recording paper is punched, and the amount of rotation angle of the drive cam required for the return operation until returning to the original position after punching. Since the configuration for forming the cam surface of the drive cam can be easily realized so as to be larger than this, drilling with low torque can be easily realized. Furthermore, when the punch is pushed up, it can be configured with a small rotation angle, so that it is possible to provide a product with good productivity while reducing wasted time.

It is a perspective view which shows the punch processing apparatus which concerns on this invention. (A) is the perspective view which shows the drive cam used for the punch processing apparatus, (b) is the perspective view which looked at the drive cam from the bottom face side. (A) is the perspective view which shows the cam holder used for the punch processing apparatus, (b) is the perspective view which looked at the cam holder from the bottom face side. (A) is a perspective view which shows the punch used for the punch processing apparatus, (b) is the front view. It is a graph which shows the conventional correlation with the rotation angle and punch stroke of the drive cam in the Example and the past. (A) is a perspective view which shows the drive cam concerning 2nd Example of the punch processing apparatus concerning this invention, (b) is the perspective view which looked at the drive cam from the bottom face side. It is a graph which shows the conventional correlation with the rotation angle and punch stroke of the drive cam in the Example and the past.

Embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows an overall perspective view of a punch processing apparatus according to the present invention.

  The punch processing apparatus 1 of this embodiment includes a punch 13, a rotary shaft 15, a drive cam 17, and a cam holder 18, and is screwed into a casing of a recording paper post-processing apparatus (not shown) via a lower bracket 11. It has been stopped.

  A substantially U-shaped upper bracket 12 is fixed to the lower bracket 11 with a screw 11a. A gap is formed between the upper bracket 12 and the recording paper so that the recording paper can pass therethrough. Is temporarily held. The lower bracket 11 is provided with a hole (not shown) slightly larger than the punch 13 at a position coaxial with the punch 13 so that the cutting edge portion at the lower end of the punch 13 can penetrate the lower bracket 11.

  The upper bracket 12 is composed of a flat surface portion 12a on the center portion side and wall surface portions 12b standing on both sides. A bearing 14 is press-fitted into the flat surface portion 12a, and a bearing 16 for rotatably supporting the rotary shaft 15 is attached to both wall surface portions 12b.

  A punch insertion hole is formed in the bearing 14 to guide the vertical movement of each punch 13.

  The rotating shaft 15 is provided with a hole for inserting a parallel pin (not shown), and a drive cam 17 is attached via the parallel pin. Thus, since the drive cam 17 is attached with the parallel pin, the rotating shaft 15 has some play between the drive cam 17 and the punch 13 provided on the drive cam 17 is the punch of the bearing 14. Even if it is slightly displaced from the insertion hole, the displacement is easily absorbed and assembled.

  As shown in FIGS. 2A and 2B, the drive cam 17 includes a cam 17a for pushing down the punch 13 (hereinafter referred to as a push-down cam) and a cam for pushing up the punch 13 (hereinafter referred to as push-up). There are two types of cams 17b. Of these, the push-down cam 17a for pushing down the punch 13 has a unique cam surface that allows the rotary shaft 15 to be rotated by 270 degrees, that is, the punch 13 can be pushed down slowly.

  On the other hand, the push-up cam 17b is formed to rotate the rotary shaft 15 by 90 degrees, that is, to lift the punch 13 at once. In FIG. 2, reference numeral 17c denotes a surface (hereinafter referred to as a neutral surface) on which the pressing cam 17a of the drive cam 17 comes into contact with the cam holder 18 described next when the punch 13 reaches the bottom dead center at which the punch 13 is lowered. ).

  As shown in FIGS. 3A and 3B, the cam holder 18 is formed in a substantially box shape and is provided so as to surround the outer periphery of the drive cam 17. The cam holder 18 has a first contact surface 18a that contacts the push-down cam 17a of the drive cam 17 and a second contact surface 18b that contacts the push-up cam 17b. Further, the cam holder 18 is provided with a notch 18c having a long hole shape as a guide for the reciprocating motion toward the upper and lower brackets 11 and 12 by the rotational motion of the drive cam 17. The notch 18c is also provided with a function of preventing the cam holder 18 from rotating in the horizontal direction.

  The cam holder 18 is pushed downward when the push cam 17 a on the drive cam 17 side contacts the first contact surface 18 a on the floor side of the cam holder 18. On the contrary, the push cam 17 b of the drive cam 17 is pushed to the ceiling of the cam holder 18. When the second contact surface 18b is lowered from the left and right side portions of the portion, the portion is lifted upward. The bottom surface of the cam holder 18 has a groove 18d for attaching the punch 13 and a hole 18e for positioning.

  The punch 13 is punched in a recording paper or the like while moving up and down together with a cam holder 18 that reciprocates in the vertical direction while being guided by a bearing 14 that is press-fitted. Therefore, as shown in FIGS. 4 (a) and 4 (b), the punch 13 has a cutting edge at the bottom, and a neck 13c that is constricted to be inserted and mounted in the groove 18d in an engaged state at the top. Is formed. In addition, the lower end portion of the blade edge has an uppermost portion 13b formed in a concave shape and a lowermost portion 13a formed in a sharp edge shape at both end portions sandwiching the uppermost portion 13b.

Next, the operation of the punch processing apparatus according to this embodiment will be described.
A recording sheet on which an image is formed by the image forming apparatus and conveyed through the recording sheet post-processing apparatus is subjected to punch processing when passing through the punch processing apparatus 1 shown in FIG.

  Prior to the recording paper to be punched being conveyed to the punch processing apparatus 1, the punch 13 is lifted by the push-up cam 17b of the drive cam 17 so as not to obstruct the recording paper conveyance operation. Waiting in the state. The rotation posture of the drive cam 17 at this time (the state where the push-up cam 17b is vertically upward) is defined as a home position (hereinafter abbreviated as HP). In this embodiment, the recording paper conveyance operation is temporarily stopped to form the punch holes. However, the punching holes may be formed while being conveyed at a predetermined speed.

  The recording paper transported in the recording paper post-processing apparatus is controlled to pause at the transport position (hereinafter referred to as processing position) where the punching process is performed, and when the recording paper stops at the processing position, A driving force from a motor which is a drive source (not shown) is transmitted to the rotary shaft 15, and the rotary shaft 15 rotates the drive cam 17 via a parallel pin (not shown).

  When the drive cam 17 starts rotating, the first contact surface 18a of the cam holder 18 is gradually pushed downward by the pressing cam 17a of the drive cam 17. When the cam holder 18 is pressed by the drive cam 17, the punch 13 integrated with the cam holder 18 is also pressed. When the cutting edge of the punch 13 reaches the recording paper by the rotation of the drive cam 17, the punching is gradually performed. This drilling operation is performed between the lowermost portion 13a and the uppermost portion 13b at the cutting edge of the punch 13.

  When this drilling operation is completed, the drive cam 17 is further rotated, and when it is rotated 270 degrees, the punch 13 is moved to the bottom dead center. At this time, the stroke amount of the punch 13 is maximized, and the drive cam 17 presses the first contact surface 18a of the cam holder 18 with the neutral surface 17c of the press cam 17a.

  In this way, the punch 13 pressed by the rotating operation of 270 degrees by the rotating shaft 15 and the driving cam 17 rotating integrally with the rotating shaft 15 is rotated by the remaining 90 degrees by the driving cam 17, and the pushing cam 17 b Thus, the second contact surface 18b is lifted at once. Accordingly, the punch 13 is also detached from the recording paper and lifted upward, and returns to the original position (hereinafter abbreviated as HP).

  Here, as for the punch 13 after punching the recording paper, even if it returns slowly to the initial position or returns quickly at once, there is no adverse effect on the already formed punch, so it is as fast as possible. By returning to HP, it is possible to shorten the punching time for one round.

  Next, the drive cam rotation angle and the punch stroke amount in this embodiment and the prior art will be described with reference to FIG. In FIG. 5, the horizontal axis represents the rotation angle of the drive cam, and the vertical axis represents the stroke amount of the punch. The broken line is the characteristic when using the structure shown in the prior art (hereinafter, conventional type), and the solid line is the characteristic when using the drive cam 17 and punch 13 according to this embodiment (hereinafter, the embodiment type). Respectively.

  When the punch stroke amount is point A, the lowermost part of the punch edge portion (position 13a in this embodiment) reaches the recording paper, and when the stroke amount is point B, the punch is the uppermost portion of the blade edge portion (this embodiment). Then pass the position 13b). Both the prior art and this embodiment have the same punch stroke amount, and are HP when the rotation angle of the drive cam is 0 degree or 360 degrees.

  As described above, with the conventional type drive cam, the punch reaches the maximum stroke when it is rotated 180 degrees, and returns to HP with the remaining 180 degrees of rotation. On the other hand, in this embodiment type, the punch 13 reaches the maximum stroke when it is rotated by 270 degrees, and returns to HP by the remaining 90 degrees of rotation.

  As can be seen from the figure, the torque is most required during the 360-degree rotation angle of the drive cam during punching (in the case of this embodiment type, the lowermost portion 13a of the punch 13 is the recording paper. Until the uppermost part 13b penetrates and passes through the recording paper). Comparing the amount of rotation angle between the conventional type and this example type at this time, this example type is larger.

  For the conventional type and this example type, when the punch stroke amount is constant (point A to point B) and the rotation shaft rotates at the same angular velocity, the larger the rotation angle amount of the drive cam, the greater the punch Since 13 slowly strokes, this embodiment type can drill with lower torque than the conventional type. That is, this is because the stroke displacement amount per unit time (proportional to the differential coefficient within a certain region for the function corresponding to each graph) can be reduced.

  In this embodiment type, the punch 13 is slowly pushed down at a rotation angle of 270 degrees, and the punch 13 is quickly lifted at a rotation angle from 270 degrees to 360 degrees, that is, the remaining 90 degrees. However, after the punch 13 is slowly pushed down with a rotation angle of 0 to 270 degrees, an elastic body such as a spring is used for the remaining 90 degrees to use the punch 13. The same effect can be obtained by quickly lifting the.

Next explained is the second embodiment of the invention.
In this embodiment, the same members as those in the first embodiment are denoted by the same reference numerals to avoid redundant description.

  In the punch processing apparatus 1 of the second embodiment, only the driving cam 27 is different in shape from the first embodiment, and other members, that is, the punch 13, the rotary shaft 15, and the cam holder 18 are different. Are the same as those in the first embodiment.

  In the drive cam 27, as shown in FIG. 6, the pressing cam 27 a is composed of a forward movement surface 271, a perforated surface 272, and a moving surface 273.

  The forward movement surface 271 is configured to reach the lowermost portion of the punch edge portion to the recording paper by pressing down on the first contact surface of the cam holder, and is configured in an angle range of 0 degrees to 60 degrees. .

  The punching surface 272 is configured to allow the recording paper to slowly pass through from the lowermost portion to the uppermost portion of the punch edge portion by contacting the first contact surface of the cam holder, and is configured in an angle range of 60 degrees to 180 degrees. Has been.

  The moving surface 273 contacts the first contact surface of the cam holder to move the punch to the bottom dead center (at this time, the drive cam 27 is in contact with the first contact surface of the neutral surface 27c). The angle range is from 270 degrees to 270 degrees.

  Next, the rotation angle of the drive cam and the stroke amount of the punch in the second embodiment and the prior art will be described with reference to FIG. In FIG. 7, the horizontal axis, the vertical axis, the broken line, and the solid line are the same as those in FIG. 5 in the first embodiment.

  As can be seen from this figure, the drive cam of the conventional type reaches the maximum stroke at the rotation angle of 180 degrees and returns to HP in the range of the rotation angle of 180 degrees. The rotation angle of 27 reaches 270 degrees and reaches the maximum stroke, and returns to HP in the remaining 90 degrees of angle range.

  Among the 360 degrees of the rotation angle of the driving cam, the torque is most required when punching (from the time when the lowermost part of the punch reaches the recording paper until the uppermost part passes the recording paper). is there. Comparing the amount of rotation angle of the driving cam between the conventional type and that of this embodiment type, this embodiment type is larger.

  When the punch stroke amount is constant (from point A to point B), the larger the rotation angle amount, the slower the punch moves, so that the punch can be drilled with lower torque than the conventional type.

  By the way, as described above, the drive cam 27 of the second embodiment is different in four types of angle regions of 0 to 60 degrees, 60 degrees to 180 degrees, 180 degrees to 270 degrees, and 270 degrees to 360 degrees. It is comprised so that it may have a surface.

  In particular, in this embodiment type, the angle region where the rotation angle of the drive cam 27 is 0 to 60 degrees is the forward movement surface, and reaches the recording paper earlier in time than the conventional type. In this angle region, since it is not directly related to punching, it reaches the recording paper quickly, and accordingly, a substantial punching time can be ensured for punch punching, and the punching work time can be shortened. I can plan.

  In this embodiment type, in order to enable drilling with low torque, that is, to enable the punch to stroke as slowly as possible, the rotation angle of the drive cam 27 is 120 degrees from 60 degrees to 180 degrees. The angle is large enough with the degree as the perforated surface.

  For example, when the rotation angle of the driving cam of the conventional type and that of this embodiment type is compared between the points A and B in FIG. 7, the rotation angle of this embodiment type is larger. The stroke displacement amount is small, and the punch 13 can be slowly stroked. By performing the stroke of the punch 13 at the time of drilling which is most loaded, the drilling operation can be performed with a torque lower than that of the conventional type. The wider this angular area, the lower the torque can be drilled.

  In this embodiment type, as described above, when the rotation angle of the drive cam 27 reaches 180 to 270 degrees, the punch that has finished the drilling operation reaches the bottom dead center.

  In this embodiment type, the punch returns to HP when the rotation angle of the drive cam 27 is 270 to 360 degrees. In this case, another cam surface, that is, the push-up cam 27b is used. Thus, the push-up cam 27b presses and pushes the second contact surface of the cam holder and returns to HP.

1 Punch Unit 11 Lower Bracket 12 Upper Bracket 13 Punch 14 Bearing (Guide)
DESCRIPTION OF SYMBOLS 15 Rotating shaft 16 Bearing 17 Drive cam 17a Push-down cam 17b Push-up cam 18 Cam holder 27 Drive cam 271 Forward surface 272 Drilling surface 273 Moving surface

Claims (3)

A punch processing apparatus that punches punch holes in recording paper discharged from an image forming apparatus,
A driving cam that is fixed to a rotating shaft that is rotated by a driving source such as a motor and that is rotated by the rotating operation;
A cam holder that integrally attaches a punch for punching the recording paper and reciprocates by the rotation of the drive cam;
A guide member for guiding the movement of the punch,
The rotational angle amount of the drive cam required for the punching operation until the recording paper is punched by pressing the punch, and the rotational angle amount of the drive cam required for the return operation until the original position after the punching is restored. The punch processing apparatus is characterized in that the cam surface of the drive cam is formed so as to be larger than. The cam surface of the drive cam has a forward movement surface that contacts the cam holder until the punch reaches the recording paper from the home position, a punching surface that contacts the cam holder until the punch punches the recording paper, and the punch finishes the punching operation. And a surface that contacts the cam holder until reaching the bottom dead center,
The cam surface of the drive cam is formed so that the punch movement amount per unit rotation angle of the drive cam is the smallest in the perforated surface compared to other cam surfaces. Punch processing equipment.   The drive cam has two types of cams: a push-down cam that pushes the cam holder and presses the punch, and a push-up cam that pushes the cam holder and lifts the punch. Punch processing equipment.

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