JPH09248707A - Boring blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent anyone of burrs in protrusion shape, tears or cracks, etc., from taking place when a preset-sized hole is opened in a synthetic resin plate, and a hard rubber plate, etc. SOLUTION: A knife-like marking-off cutting blade 2 provided with a slant blade tip 21 aiming upward by a loose angle α as approaching to the rotational direction R and a cutting-across type Russel cutting blade 3 for cutting a ring- shape groove of a preset width W are provided, and a step E is provided between the marking-off cutting blade 2 and the Russel cutting blade 3 so that the blade tip end of the marking-off cutting blade 2 may precede, by a preset dimension, blade tip end of the Russel cutting blade 3 in the cutting depth direction from the blade tip end of the Russel cutting blade 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piercing blade, and more particularly to a piercing blade suitable for making a hole of a predetermined size in a plate material such as synthetic resin or hard rubber or a hollow product thereof.

[0002]

2. Description of the Related Art As a conventional piercing blade of this kind, the actual cutting blade is 5
The perforating blades disclosed in JP-A 5-142214, JP-A-59-86909, JP-A-59-140117, etc. are known.

The drilling cutter disclosed in Japanese Utility Model Laid-Open No. 55-142214 is a drilling cutter designed to be suitable for drilling large-diameter holes in aircraft structural members, as shown in FIG. At the lower edge of the blade cylinder 51 having the blade bag 51a at the lower edge portion, a blade composed of at least a pair of outer blade 53 and inner blade 52 whose cutting positions are slightly different from each other is provided, and the outer blade 53 is pointed outward and the blade is pointed inward. The inner blades 52 are each formed such that the rake angle δ is a negative angle, and the inner and outer blades 5
2 and 53 move so as to draw a pair of inner and outer concentric circles, so the inner and outer blades cut the surface of the material to be punched while scoring until the inner and outer blades are exposed on the back surface of the material to be drilled. When inserted, a through hole having the same size as the locus of the blade edge of the outer blade 53 is punched. At this time, the rake angle δ
With a negative angle, it is possible to prevent excessive cutting of the inner and outer blades into the material to be drilled. The symbol R indicates the rotation direction of the punch cutter.

Next, the hole saw disclosed in Japanese Utility Model Laid-Open No. 59-86909 discloses that when a hole is made in a hard resin plate, a wood plate, an iron plate or the like, disc-shaped chips are easily discharged from the inside of the hole saw to the outside. With a hole saw designed for the purpose of making it possible, as shown in FIG. 6, the inner peripheral surface of the blade portion is tapered downward 69 toward the outer side in the radial direction of the main body so that chips are contained in the blade portion. It is in a state that it is easily disengaged from the fitting with the peripheral surface side.

The hole saw shown in Japanese Utility Model Laid-Open No. 59-140117 is installed at the tip of the cylinder of the hole saw as shown in the front view of FIG. 7A and the bottom view of FIG. A large number of cutting edges are divided into several groups and divided into several groups, and the tips of the cutting edges 73, 74, and 75 in the group are sequentially drawn with a step from the first cutting edge in the direction of rotation, and the outer circumference is drawn as the step of the cutting edge pulls in. It is a hole saw with a cutting edge with a small radius, and each cutting edge is provided with an angle B that pushes out all the chips in the outer circumferential direction. And, the step of this cutting edge and the change in the outer circumferential radius provided according to the step By combining the functions of the cutting edge and the angle provided on each cutting edge, it is possible to efficiently cut deep holes without interrupting the work for removing chips. It is over.

[0006]

The hole saw shown in FIGS. 6 and 7 among the conventional blades for boring described above,
The cutting blade formed on the lower edge of the blade portion is inclined downward as it goes forward in the rotation direction, and as a result,
A rake face having a regular rake angle δ is formed on the front part of the cutting edge.

In the piercing cutter shown in FIG. 5, the rake angle δ of the rake face of the inner and outer blades is formed to be a negative angle, but the negative angle is small and its shape is small. Is a reverse rake surface at an angle close to a right angle with respect to a surface perpendicular to the axis of the cylindrical blade cylinder.

As described above, a synthetic resin plate is formed by the conventional blade for perforation in which the rake face having the regular rake angle δ is provided in the front portion in the rotation direction or the reverse rake face having a negative angle with a small value is provided. When a hole of a predetermined size is made in a hard rubber plate, etc., there is a problem that burrs, chips, and other defects occur because the material to be perforated is forcibly cut off by the cutting blade, especially the hard rubber plate. Or, in the case of perforating a plate or hollow product such as polypropylene that is soft among synthetic resins, a large problem that a burred burr remains on the back surface side of the material to be perforated and post-processing takes time and effort. was there.

The present invention has been made in view of the above-mentioned conventional drawbacks, and it is a sag-like burr for making a hole of a predetermined size in a plate material such as synthetic resin or hard rubber or a hollow product thereof. An object of the present invention is to provide a piercing blade capable of forming a clean hole without requiring post-treatment without causing tearing or chipping.

[0010]

The present invention adopts the following means in order to solve the above technical problems. The first invention to obtain a patent is a shank,
A cylindrical body concentrically provided under the shank,
Consisting of a plurality of cutting blades provided at the bottom of the cylinder of the body,
The plurality of cutting blades is a punching blade composed of at least one scoring blade and at least one Russell cutting blade, the outermost diameter of which is the same as the diameter of the hole to be pierced. The cutting blade includes an outer peripheral side surface of the scoring blade, an inclined blade tip of a predetermined length that is upward at a predetermined loose angle as it goes downward in the rotation direction of the scoring blade, and from the inclined blade tip. A cutting edge having a cutting edge portion formed by an inner peripheral side surface that is a tapered surface that approaches the axis of the main body as it goes upward, and the Russell cutting edge is an outer peripheral side surface and an inner peripheral side surface of the Russell cutting edge. Is formed by a blade width of a predetermined dimension formed by the following, a flank face which is upward at a predetermined angle as it goes in the counter-rotational direction under the Russell cutting blade, and a rake face provided in the front portion in the rotational direction. A cutting edge with a parting-off type cutting edge for scoring And the blade tip providing a step in the cutting tip and the Russell cutting tip for 該罫 writing to a predetermined size prior to a depth cutting direction than the Russell cutting tip.

As described above, the outer peripheral side surface, the inclined blade tip having a predetermined length that is directed upward at a predetermined gentle angle as it moves in the rotational direction, and the tapered surface that approaches the axial direction of the main body as it goes upward from the inclined blade tip. The cutting edge part of the cutting edge for scoring formed by the inner peripheral side surface and the sharp edge point, and
Since the approach angle to the material to be perforated is small, it is possible to easily cut into the material to be perforated and form a scoring circular kerf having the same size as the diameter of the perforation.

In addition, the scoring cutting blade tip and the Russell cutting blade tip are arranged so that the cutting edge of the scoring blade precedes the cutting edge of the Russell cutting blade, which is actually in charge of cutting, in the cutting depth direction. Since there is a step in the Russell cutting edge, the Russell cutting edge always cuts the inside after the circular scoring groove is machined, and the Russell cutting edge is cut. The side surface of the hole is not forcibly scraped off, and it progresses to the end in this state.As a result, no burrs like burrs are left on the back surface of the material to be drilled or chipped, and a clean hole is drilled. You will be able to.

Further, since not only the scoring blade for scoring is used for piercing, but the subsequent Russell cutting blade having a blade width is used for piercing, the tip of the scoring blade for scoring is not overpowered. Even if the cutting edge of the writing cutting edge is made sharper, it becomes possible to form a sharp circular kerf for a long period of time.

A second invention to be patented is that the inclination angle of the inclined blade tip gradually increases upward as it goes in the rotational direction at the lower part of the scoring blade 1 with respect to a plane perpendicular to the main body axis.
The punching blade according to claim 1, wherein the punching blade has an angle in a range of 0 to 30 degrees, and more specifically, an entrance angle of the cutting blade of the scoring blade with respect to the material to be punched. It is shown.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The punching blade of the present invention has two types of cutting blades having different shapes called a scoring blade and a Russell cutting blade, which are provided at the bottom of a cylindrical main body which is concentrically provided with a shank. One or more, preferably two or more are provided.
The diameter of the outermost circumference of each cutting edge is set to be the same as the diameter of the hole to be drilled.

The cutting blade portion of the scoring blade, which is one of the two types of cutting blades, has an outer peripheral side surface of the scoring blade and a lower angle at a lower portion thereof in the rotational direction. It is formed by an inclined blade tip of a predetermined length that is directed upward and an inner peripheral surface that is a tapered surface that approaches the axial center of the main body as it goes upward from the inclined blade tip, and forms a so-called knife blade.

Next, the other Russell cutting edge, which is the other cutting edge, has a blade width formed by the outer peripheral side surface and the inner peripheral side surface that is inside by a predetermined dimension from the outer peripheral side surface, and the Russell cutting blade rotates. A rake face is provided in the front part of the direction, and a flank face is provided in the lower part to form a so-called cutting edge.

Then, a step is provided at the height of both cutting edges so that the cutting edge for the scoring blade has a cutting edge ahead of the cutting edge of the Russell cutting blade in the cutting depth direction. As a result, before the scraping of the material to be perforated with the Russell cutting edge, the outer diameter of the perforation is the same as the outer diameter of the perforated cutting edge, and the outermost portion is the deepest and the cross section is a square groove with a square cross section. Will be processed.

In addition, the inclination angle of the inclined blade point which is directed upward as it goes in the direction of rotation at the lower part of the scoring blade should be within the range of 10 to 30 degrees with respect to the plane perpendicular to the axis of the main body. Is effective. Further, the number of scoring cutting edges and the number of Russell cutting edges do not necessarily have to be the same, but the positions of the respective cutting edges are equally distributed from the viewpoint of the balance of the cutting load and the rotation balance. It is preferable.

[0020]

Embodiments of the punching blade of the present invention will now be described with reference to the drawings. FIG. 1 shows a perforating blade according to the present invention.
It is a front view which shows an Example, and FIG. 2 is a side view of FIG. In FIGS. 1 and 2, the cylindrical main body 1 provided below the shank 4 is concentric with the shank 4. On the lower part of the cylindrical main body 1, a scoring blade 2 for processing a circular kerf on a material to be drilled by rotation and a cut-off type Russell for scraping the material to be drilled into a ring shape with a predetermined width W. The cutting edge 3 is provided concentrically with the main body axis. The diameter D of the outermost cutting edge of the scoring blade 2 and the Russell cutting blade 3 is the same as the diameter of the hole to be punched, and blade bags 2a and 3a are provided in front of the cutting blades 2 and 3 in the rotational direction. It is used as a refuge for shavings.

At the lower part of the scoring blade 2, there is provided an inclined blade point 21 which opens in the rotational direction R at a gentle angle α.
The inner peripheral surface side is a tapered surface 9 starting from the inclined blade tip 21, and a sharp knife-shaped single blade is formed on the inclined blade tip 21, and the outermost dimension of the perforated material is D by the rotation of the main body 1.
A circular kerf with a square cross section is processed.

Next, the Russell cutting edge 3 is a cut-off edge having a width W, a rake face 31 having a rake angle δ is provided on the front surface in the rotating direction R, and a clearance angle ε is provided on the lower portion. The flank 32 is provided, and the ring-shaped groove whose outer diameter is D and whose inner diameter is (D-2W) is cut by the rotation of the main body 1.

With respect to the scoring blade 2 and the Russell cutting blade 3 having the above-described shapes, the tip of the scoring blade 2 is ahead of the tip of the Russell blade 3 in the cutting depth direction. Is provided with a step E. By providing this step E, the Russell cutting edge 3 can scrape the inside of the Russell cutting edge 3 in a ring shape along the circular kerf previously processed by the scoring cutting edge 2. The side surface is a clean machined surface attached by the scoring blade 2.

In the case of the present embodiment, the edging angle 2 of the scoring blade 2 is 10 degrees, and the angle γ of the inner peripheral surface side tapered surface 9 is 30.
The clearance angle β on the back side is 75 degrees, the blade width W of the Russell cutting edge 3 is 3 mm, the rake angle δ is 5 degrees, and the clearance angle ε is 5 degrees. An alloy tip was used for brazing and fixing to the main body 1 made of rolled steel for general structure. The step E between the scoring blade 2 and the Russell blade 3 has a value of 0.5 mm, the outermost diameter D of both blades 2 and 50 is 50 mm, and a clean hole is punched in a polypropylene plate having a thickness of 10 mm. We were able to. Moreover, even if the angle of inclination α of the cutting edge 2 for scoring was 30 degrees, it was possible to open a good hole without sagging, but when the angle of inclination α of the angle was 5 degrees, heat generation increased. Moreover, when the blade tip inclination angle α is set to 35 degrees, some sagging occurs on the lower surface of the perforated material.

In this embodiment, the piercing blade without the center drill for centering is described, but the center drill may be provided if necessary. Moreover, although the inclined blade tip of the scoring blade has been described as being linear, it may be a curved blade tip that is concave upward.

Next, another embodiment will be described with reference to FIGS. 3 is a front view of a main part of another embodiment, and FIG. 4 is a bottom view of FIG. The present embodiment is one embodiment of the perforating blade according to the present invention, which is effective when the perforating diameter is small. In the figure, an outer diameter D of a cylindrical main body 1 provided at a lower portion of a shank (not shown) is 8 mm, and a scoring blade 2 and a Russell blade 3 are provided on the lower portion thereof.
Are continuously provided in the form of leading in the rotation direction R,
A blade bag 3 a is provided in front of the Russell cutting blade 3. In this embodiment, the angle of inclination α of the scoring blade 2 is 15 degrees and the angle γ of the taper surface 9 on the inner peripheral surface side is 30 degrees, but the clearance angle β on the back side is 90 degrees. did. Further, the blade width W of the Russell cutting edge 3 was 0.5 mm, and the rake angle δ of the rake face 31 was 0 °. However, the rake face has an inclination angle θ at which cutting chips are released in the axial direction of the main body 1. To reduce cutting resistance. Also in this embodiment, the value of the step E between the scoring blade 2 and the Russell blade 3 is 0.5 mm.

[0027]

As described above, the present invention has a sharp beveled edge, and the angle of approach of the beveled blade tip with respect to the material to be perforated is a gentle inclination, so that the material to be perforated is reasonably clean. Since the tip of the scoring cutting edge with a cutting edge that can process the cutting edge is configured to precede the edge of the Russell cutting edge that is actually in charge of cutting in the cutting depth direction, synthetic resin When a hole having a predetermined size is formed in a plate material such as a hard rubber or a hollow product thereof, a sag-like burr does not remain on the back surface side of a material to be perforated or a chip does not occur. Further, since the phenomenon of forcibly scraping off the perforated side surface with the Russell cutting edge does not occur, a clean perforated side surface can be obtained without causing peeling-like fluffing.

Furthermore, since not only the scoring blade is used for piercing, but the subsequent Russell cutting blade having a blade width is used for piercing, the scoring blade is not overly forceful. Even if the cutting edge portion is used as a sharper blade, it becomes possible to process a sharp circular kerf for a long time, and the life of the entire piercing blade is extended.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a punching blade according to the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a front view of a main part of a punching blade showing another embodiment of the present invention.

FIG. 4 is a bottom view of FIG. 3;

FIG. 5 is a front view showing a conventional punch cutter.

FIG. 6 is a cross-sectional view showing a conventional hole saw.

FIG. 7 is a front view and a bottom view showing another example of a conventional hole saw.

[Description of sign]

 1 Main Body 2 Cutting Edge for Marking 3 Russell Cutting Edge 4 Shank 9 Tapered Surface 21 Inclined Blade Tip 31 Rake Surface 32 Flank Surface 2a Blade Bag 3a Blade Bag 51 Tool Barrel 52 Inner Blade 53 Outer Blade 69 Tapered Surface R Rotational Direction E Step

Claims (2)

[Claims] 1. A shank, a cylindrical main body concentrically provided at a lower portion of the shank, and a plurality of cutting blades provided at a lower cylindrical portion of the main body, the plurality of cutting blades being cutting blade portions. A piercing blade comprising at least one scoring blade and at least one Russell cutting blade whose outermost peripheral diameter is the same as the piercing diameter, wherein the scoring blade is the scoring blade. The outer peripheral side surface of the scoring blade, a slanting blade tip of a predetermined length that faces upward at a predetermined loose angle as it goes in the direction of rotation at the lower part of the scoring blade, and the axial center of the main body as it goes upward from the slanting blade tip. Is a cutting edge having a cutting edge portion formed by a tapered inner peripheral side surface, the Russell cutting edge having a predetermined size formed by an outer peripheral side surface and an inner peripheral side surface of the Russell cutting edge. Width and predetermined according to the counter-rotational direction at the bottom of the Russell cutting edge A cutting edge having a cutting edge part of a cut-off shape formed by a flank facing upward at an angle and a rake surface provided in the front part in the rotation direction, and the tip of the scoring edge for scoring is the Russell cutting edge. A piercing blade, wherein a step is provided between the tip of the scoring cutting blade and the tip of the Russell cutting blade so as to precede the tip by a predetermined dimension in the cutting depth direction. 2. The inclination angle of the inclined blade tip, which gradually rises upward as it goes in the direction of rotation at the lower part of the scoring blade, is within a range of 10 to 30 degrees with respect to a plane perpendicular to the axis of the main body. The punching blade according to claim 1, wherein