JP2014117788A - Drill hole opening processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hole processing method which performs hole processing with high quality of hole by using a drill, when a workpiece 10 formed by sticking glass epoxy resin 2 and felt 3 to cowhide or artificial leather 1 is subjected to hole opening processing, when the processing is performed by laser processing, the surrounding of the hole burns and when the processing is performed by punch processing, a ring-shaped mark is left on the surrounding of the hole, so as to avoid the problems, hole opening is performed by a drill processing, but by using aluminum generally used as an upper plate 4, and paper phenol generally used as a lower plate 5, deposition of aluminum on the surrounding of the hole and fuzz in an inner part of the hole are generated, so the hole quality deteriorates.SOLUTION: Pet resin is used as an upper plate 4 and ABS resin is used as a lower plate 5 to perform drill hole opening processing. Thereby, deposition of aluminum on the surrounding of the hole and fuzz in an inner part of the hole are not generated so much and achieves excellent hole quality.

Description

  The present invention relates to a drilling method for machining high-quality holes at high speed using a drill in cow leather and artificial leather.

  Conventionally, an epoxy resin-impregnated glass fiber cloth sheet 2 (hereinafter referred to as glass epoxy resin) and felt (microfiber) 3 are bonded to cowhide or artificial leather 1 as shown in FIG. 4 and a thickness of 0.8 mm to 1.5 mm. In order to make a hole in the workpiece 10, laser processing or punching has been performed. However, in the case of laser processing, the periphery of the hole is burnt, and in the case of punching, the use of male and female molds causes a ring-shaped mark to be created around the hole. there were.

  It is better to drill with a drill to prevent the above-mentioned burn around the hole and the ring-shaped mark. In the case of drilling with a drill, as shown in FIG. 4, the workpiece 10 is processed by being sandwiched between the upper plate 4 and the lower plate 5. Usually, the upper plate 4 is made of aluminum, and the lower plate 5 is made of phenol. Resin-impregnated paper (hereinafter referred to as paper phenol) is used (see Patent Documents 1 to 3).

JP 2003-209334 A JP 2003-334708 A Japanese Patent Laid-Open No. 4-122506

  However, when such a leather-based workpiece is drilled by sandwiching a conventional aluminum upper plate and a paper phenol lower plate, aluminum welding may occur around the hole, or inside the hole. There is a problem that the quality of the hole is low due to the occurrence of uncut felt (fluffing). The present invention aims to provide a method that can solve this problem.

  Referring to FIG. 4, a work (10) formed by laminating glass epoxy resin (2) and felt (3) to cowhide or artificial leather (1) is sandwiched between an upper plate (4) and a lower plate (5). In the drilling method performed using a drill, it is preferable to use PET resin (polyethylene terephthalate resin) as the upper plate (4) and ABS resin (acrylonitrile / butadiene / styrene resin) as the lower plate (5).

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, it does not have any influence on description of a claim by this.

  By drilling with the above configuration, drilling with good hole quality can be achieved with less aluminum welding and fuzz inside the hole. Furthermore, the processing time can be shortened.

It is the drawing substitute photograph which showed the state of the hole by the processing method of this invention. (Example) It is the drawing substitute photograph which showed the state of the hole by the conventional processing method. (Comparative Example 1) It is the drawing substitute photograph which showed the state of the hole by the conventional processing method. (Comparative Example 2) It is sectional drawing which shows the state which pinched | interposed the workpiece | work with the upper board and the lower board from the upper and lower sides for drilling.

(Example)
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a drawing-substituting photograph showing the state of a hole viewed from the front side (cowhide side) and the back side (felt side) according to the processing method of the present invention. The workpiece 10 is obtained by bonding a glass epoxy resin 2 and a felt 3 to cowhide 1 and has a thickness of 0.8 mm to 1.5 mm. The upper plate and the lower plate were as follows.
Upper plate: PET resin (thickness 0.25 mm or 0.35 mm)
(PET resin preferably has a thickness of 0.25 mm or more.)
Lower plate: ABS resin Drill developed product:
Drill diameter: 1.2mm diameter
Drill twist angle: 40 °
Drills and other specifications: Tip angle 150 ° / 2 No. clearance angle 15 ° /
Core thickness 0.15mm / groove width ratio 2.0
General drills:
Drill diameter: 1.2mm diameter
Drill twist angle: 35 °
Drills and other specifications: Tip angle 130 ° / 2 No. clearance angle 15 ° /
Core thickness 0.14mm / groove width ratio 1.8
Drill rotation speed: 80,000 min ^-1
Cutting speed: 1.5 m / min
Tip bush inner diameter: 3.0mm diameter
Here, as can be seen from FIG. 1, the hole quality is sufficiently good (◯) even with a general drill, but it becomes even better when a drill is developed (◎). This is thought to be due to the fact that the larger the twist angle of the drill, the better the cutting of soft objects such as leather. Therefore, it is preferable to set the twist angle to 40 ° or more. In addition to the above, processing with good hole quality can be performed within the following range.
Drill diameter: 1.0mm to 1.5mm in diameter
Drill and other specifications: Tip angle 130 ° to 150 ° / No. 2 clearance angle 12 ° to 15 ° /
Core thickness 0.14 mm to 0.16 mm / groove width ratio 1.8 to 2.2
Drill rotation speed: 60,000 min ^{−1 to} 100,000 min ⁻¹
Cutting speed: 1.0 m / min to 5.0 m / min
Tip bush inner diameter: 1.8mm to 5.0mm in diameter
In the conventional conditions, the drill rotation speed was set to 40,000 min ⁻¹ to 50,000 min ^{−1 in} order to prevent drill wear and prolong the drill life. To emphasize this, high-speed rotation was used and the chip load was lowered. In addition, the inner diameter of the conventional tip bush is often 9.8 mm, but in this processing method, in order to suppress burrs, the vicinity of the processing point can be pressed and a certain amount of dust collecting ability can be secured. The one with a small inner diameter was used. Furthermore, when PET resin was used, burr was suppressed and processability was good, but nesting to the drill had to be prevented, so air was blown to the processing point.

  In addition, although the flat workpiece 10 was used in the present Example, even if it is the curved workpiece 10, the upper plate and the lower plate used in this processing method are easy to mold and deform and have good workability. Can be processed without problems. Further, the conventional cutting speed is 2.0 to 4.0 m / min. However, since high-quality drilling can be performed even at a high cutting speed of 5.0 m / min, the processing time can be shortened.

(Comparative Example 1)
FIG. 2 is a drawing-substituting photograph showing the state of a hole when conventionally used aluminum is used as the upper plate. The workpiece 10 is the same as that of the embodiment. The upper plate and the lower plate were as follows. Other conditions are the same as in the above embodiment.
Upper plate: Aluminum (thickness 0.15 mm)
Lower plate: ABS resin Other processing conditions are as described in the figure. Aluminum welding occurs so that white bright spots can be seen in the circled portion of the photograph from the front side.

(Comparative Example 2)
FIG. 3 is a drawing-substituting photograph showing the state of a hole when paper phenol conventionally used as a lower plate is used. The workpiece 10 is the same as that of the embodiment. The upper plate and the lower plate were as follows. Other conditions are the same as in the above embodiment.
Upper plate: Aluminum (thickness 0.15 mm) or
PET resin (thickness 0.25mm or 0.35mm)
Lower plate: Paper phenol Other processing conditions are as described in the figure. As can be clearly seen by comparing with FIG. 1, the uncut felt (fluff) of the felt (microfiber) can be seen.

1 Leather 2 Glass epoxy resin 3 Felt (microfiber)
4 Upper plate 5 Lower plate 10 Workpiece

Claims (1)

In a drilling method that uses a drill, sandwiching a work made by attaching glass epoxy resin and felt to cowhide or artificial leather between the upper and lower plates,
PET resin is used as the upper plate,
A drilling method characterized by using an ABS resin as the lower plate.