JP3372315B2 - Perforator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a punching device for punching a thin metal plate such as aluminum or steel.

[0002]

2. Description of the Related Art A thin metal plate such as aluminum or steel is used as a support for a PS plate for lithographic printing. Since the PS plate is mounted on a printing machine for use, it is necessary to punch holes for mounting the PS plate. The punching device used for this purpose is provided with a punch (movable blade) having a punching shape of a punch hole and a die (fixed blade) having a hole shape into which the tip of the punch fits. A sheet-like thin metal plate is sandwiched between a punch and a die for perforation. Regarding the sheet-shaped thin metal plate, a plurality of these may be laminated and perforated.

In order to maintain a good punching shape of the punch holes, the punch and the die are made of a hard metal material, and the shape of each cutting edge is processed with high precision, and the surface roughness of the cutting edge is made fine enough. There is a need. For this reason, in the past, SKH material was used for the punch and SKH was used for the die.
Material D is used, and the surface roughness of the cutting edge is 1.0 to 2.
It is about 0 μm. In addition, the clearance between the punch and the die at this time is generally about 5 to 8% of the plate thickness of the metal thin plate to be punched.

Further, in the course of repeated perforation, chips from a thin metal plate often adhere to the cutting edge to deteriorate the sharpness, so that it is also described in JP-A-61-241096. In this way, interleaving paper such as polyethylene laminated paper is stacked on the surface of the metal thin plate, and the perforation is performed from above. According to this method, the cutting powder adhered to the surface of the cutting edge is wiped off by the interleaving paper, and the sharpness can be maintained to some extent.

[0005]

However, interleaving paper mixed with resin fibers, such as polyethylene laminated paper, must be treated as industrial waste after its use, which is problematic from the viewpoint of resource protection and recycling. . An aluminum thin plate (thickness: 0.15 mm) is formed by using a punch made of SKH material and a die made of SKD material in which the surface roughness of the cutting edge is 1.0 to 2.0 μm, using polyethylene mixed paper as interleaving paper.
Even when the holes are drilled in the hole, when the number of holes is about 10 to 20 times, as shown in FIGS. 10 and 11, a circle (φ4 m
m) punch hole 2, oval punch hole 3 (6 × 10
mm), swells 4, 5 and scratches 6 occur around the punch holes, which is a problem in product quality.

The cause of such a defect is that aluminum chips are aggregated on the punch or the edge of the die during repeated drilling to deteriorate the sharpness, resulting in sagging on the cut surface. The reason is that when the is raised, it rises while contacting the punch. Therefore, in the conventional punching devices, it is necessary to inspect and clean the cutting edge at the time of punching about 10 to 20 times, which is a problem in improving the work efficiency of punching.

The present invention has been made in view of the above-mentioned prior art, and it is possible to maintain the sharpness of the cutting edge satisfactorily without producing industrial waste, and further without causing the shape defect around the punch hole to be continuously formed. An object of the present invention is to provide a punching device capable of significantly increasing the number of punches.

[0008]

In order to achieve the above-mentioned object, the present invention coats the surface of the cutting edge of at least one of a punch and a die with amorphous hard carbon and has a surface roughness of 0.8 μm. It is as follows. At this time, the clearance between the punch and the die is preferably within the range of 10 to 30% of the plate thickness of the metal thin plate to be punched. Further, the blade edge of the punch is preferably a stepped shape having a height 0.5 to 2.0 times the plate thickness of the thin metal plate, or a conical shape. Furthermore, it is preferable to provide a cushioning material on the contact surface of the stripper plate with the thin metal plate.

In FIG. 4, which schematically shows the structure of the single-wafer punching apparatus using the present invention, the punch holder 12 moves up and down along the guide rod 13 by the operation of the drive mechanism 10 including the motor. A punch 14 is provided on the punch holder 12 so as to project downward, and when the punch holder 12 descends, a thin metal plate 15 conveyed in a direction perpendicular to the paper surface is sandwiched between the die 16 and a punch hole.

As shown in FIG. 5, the die 16 has an opening 16a corresponding to the outer diameter of the punch 14, and the opening 1
The punch 14 is fitted in the 6a to form a punch hole, and punch waste is discharged through the opening 16a and the opening 17a of the die holder 17. Further, the stripper plate 18 is arranged so as to abut the surface of the metal thin plate 15 so that the metal thin plate 15 does not rise together with the punch 14 when the punch holder 12 is lifted after the punch holes are opened. ing. Stripper plate 18 metal sheet 1
A buffer material 1 made of a polyethylene terephthalate (PET) sheet having a thickness of 170 μm is provided on the lower surface portion that contacts
9 is provided.

FIG. 1 schematically shows the punch 14 and the die 16. As shown by hatching in the drawing, amorphous carbon is coated from the cutting edge surface 14a of the punch 14 and the upper surface of the die 16 to the inner wall of the opening 16a. The surface roughness of these carbon-coated surfaces is 0.8 μm or less. Further, as shown in FIGS. 2 and 3, the cutting edge of the punch 14 has a columnar stepped shape, and the stepped height h is 0.5 to 2.0 times the plate thickness of the metal thin plate 15. It has become a degree.
The clearance C between the punch 14 and the die 16 is
It is within the range of 10 to 30% of the plate thickness.

FIG. 6 shows a punching device used for repeatedly punching a sheet of metal sheet 15 with interleaving paper fed by a web in synchronism with its conveyance. Members having the same functions as the constituent members of the punching device described in FIG. 5 are designated by common reference numerals. In this punching device, the stripper plate 18 is used for the punch holder 1
When the punch holder 12 is movably attached and is lowered, the stripper plate 18 first comes into contact with the stopper 22, and then the punch holder 12 is lowered against the stripper spring 23 to punch. After punching, the punch 14 and the punch 14 are lifted to a certain position, and then the stripper plate 18 is lifted.

[0013]

EXAMPLE An aluminum thin plate is used as the metal thin plate 15,
Further, in the case where polyethylene mixed paper is adhered to the surface as an interleaving paper, the conventional punching using a punch and a die shows that the number of punching is about 100 to 500 times.
As shown in Fig. 6, the swelling 5 was generated around the punch hole 3, whereas the apparatus shown in Fig. 6 was used to apply a carbon coating to the required portions of the punch 14 and the die 16 as described above to make the surface roughness 0.8 µm. In the following, in the case where the clearance between the punch 14 and the die 16 was 10% of the plate thickness, the defective shape as shown in FIG. 11 did not occur even when the number of perforations reached 5000 times.

Further, in the apparatus shown in FIG. 4, three aluminum thin sheets having polyethylene mixed paper adhered on the surface were stacked and punched with a conventional circular punch and die. When the number of punching was about 60, the sharpness was poor. As a result, the punch hole had a defective shape, but when punching was performed under the same conditions with the punch and die using the present invention, 50,000 was formed.
Even if continuous punching was performed more than once, the punch hole shape did not become defective.

Next, three 0.15 mm-thick aluminum thin plates adhered on the surface with all-pulp paper as an interleaving paper are stacked and punched with a conventional punch and die, and the cutting edge of the present invention is circular. A punch 14 having a columnar stepped shape is used, and at least one of the punch 14 and the die 16 is coated with a carbon coating so as to have a surface roughness of 0.8 μm or less. The clearance was set to 20% of the plate thickness, and a comparison was made with the case where the stripper plate 18 was provided with the cushioning material 19 on the lower surface and the punching was performed. The buffer material 1
As for 9, a PET sheet having a thickness of 170 μm was used, and the diameter of the punch 14 was φ4.0 mm, and the diameter of the cylinder of the cutting edge was φ.
The height was 2.0 mm and the column height was 0.2 mm.

In the conventional punch and die punching, a defective shape was generated around the punch holes when the punching was performed 10 to 20 times. On the other hand, in the case of punching with the punch and die of the present invention, no scratch was generated even when the number of punching times reached 5000, and the amount of swelling around the punch hole was 1/2 or less of the conventional amount. . Further, it was confirmed that there was almost no attachment of cutting chips to the cutting edge, and polyethylene cutting paper was used as the interleaving paper, and a sharpness equal to or more than that of the conventional punch and die could be maintained.

As the material for the punch and die of the present invention, not only the above-mentioned SKH material and SKD material but also various high speed steel, powder high speed steel, etc. may be used as long as they are steel materials having sufficient hardness. You can Further, the same effect can be seen when the cutting edge shape of the punch is also a conical shape, a truncated cone shape, or a prismatic stepped shape, like the punches 25 to 27 shown in FIGS.

[0018]

As described above, in the punching device of the present invention,
Amorphous hard carbon is coated on the surface of the cutting edge of at least one of the punch and die, and the surface roughness of this coating surface is set to 0.8 μm or less. It becomes difficult to adhere to and can keep good sharpness longer than ever. Also, as an interleaving paper to be stacked on the surface of a thin metal plate,
Sufficient continuous perforation is possible without using polyethylene resin.

Further, the cutting edge of the punch has a stepped shape or a conical shape having a height of 0.5 to 2.0 times the plate thickness of the thin metal plate to be punched, and the clearance between the punch and the die has a plate thickness. Since it is set within the range of 10 to 30%, the clearance between the punch and the die is maintained even after punching, and the thin metal plate is not lifted together with the punch to cause swelling or scratches around the punch hole. Further, since the buffer material is provided on the contact surface of the stripper plate with the thin metal plate, it is possible to prevent scratches caused by the contact of the stripper plate with the surface of the thin metal plate.

[Brief description of drawings]

FIG. 1 is an explanatory view of a punch and a die using the present invention.

FIG. 2 is an explanatory diagram showing a blade edge shape of a punch.

FIG. 3 is an explanatory view of a main part of the punch and the die shown in FIG.

FIG. 4 is a schematic view of a single-wafer punching device according to the present invention.

5 is a cross-sectional view of a main part of the device shown in FIG.

FIG. 6 is a schematic view of a web punching device according to the present invention.

FIG. 7 is an explanatory diagram showing a second embodiment of the shape of the cutting edge of a punch.

FIG. 8 is an explanatory view showing a third embodiment of the shape of a punch blade edge.

FIG. 9 is an explanatory view showing a fourth embodiment of the shape of the punch blade edge.

FIG. 10 is an explanatory diagram of a defect caused in a circular punch hole by a conventional single-wafer punching device.

FIG. 11 is an explanatory diagram of a defect caused in an oval punch hole by a conventional web punching device.

[Explanation of symbols]

12 punch holder 14,25,26,27 punch 15 Metal thin plate 16 dice 17 Dice holder 18 stripper plate 19 Buffer material

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A 63-203223 (JP, A) JP-A 60-227931 (JP, A) JP-A 62-265113 (JP, A) JP-A 60- 190557 (JP, A) JP 59-113938 (JP, A) Actual opening 57-32726 (JP, U) Actual opening 3-95123 (JP, U) Actual opening 5-51598 (JP, U) 4-108921 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B21D 28/34 B21D 37/01 C23C 14/06

Claims (5)

(57) [Claims] 1. A on the surface of the aluminum sheet abuts has a stripper plate for pressing the aluminum thin plate on the die side, and presses the punch into the die, the punch holes on the aluminum sheet by sandwiching an aluminum sheet between the two In a punching device for punching, at least one of the punch and the die is coated with amorphous hard carbon, and the coated surface
And a surface roughness of 0.8 μm or less . 2. The clearance between the punch and the die is
Perforating apparatus according to claim 1, characterized in that 10% to 30% of the thickness of the aluminum thin plate. 3. The cutting edge of the punch has a thickness of 0.
The punching device according to claim 2, which has a stepped shape having a height of 5 times to 2.0 times. 4. A punch blade having a blade edge of 0.
The punching device according to claim 2, which has a conical shape having a height of 5 times to 2.0 times. The contact surface between the aluminum thin plate 5. A stripper plate, according to claim 3 also characterized in that a damping material
Is a punching device according to item 4 .