KR20150028544A

KR20150028544A - Rotary Cutting Tool For Cutting A Curved Surface

Info

Publication number: KR20150028544A
Application number: KR20130107311A
Authority: KR
Inventors: 천중원; 홍승인
Original assignee: (주)세화아이엠씨
Priority date: 2013-09-06
Filing date: 2013-09-06
Publication date: 2015-03-16

Abstract

The rotary cutting tool according to the present invention is characterized in that the rotary cutting tool has a concave groove formed so as to protrude convexly with a bottom curvature having a preset bottom curvature formed with a base on the side surface of the cutting edge, It is possible to reduce the amount of the cutting tool transfer marks left on the workpiece surface at the time of cutting the curved surface portion of the workpiece so as to obtain a smoother and more excellent curved surface by forming the rounded edges of the edge surface and the continuous side surface .

Description

Technical Field [0001] The present invention relates to a rotary cutting tool for cutting a curved surface,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary cutting tool, and more particularly, to a rotary cutting tool for curved surface machining, in which a cutting edge of a cutting tool left on a workpiece surface during a cutting process of a curved surface portion having a protrusion is reduced to obtain a more smooth, .

As is well known, cutting processing means a machining method that removes unnecessary portions from a workpiece to obtain a desired shape and surface properties.

In order to perform the cutting process, the workpiece is slightly broken by shearing deformation generated locally through the relative movement of the cutting tool having hardness higher than that of the workpiece and the workpiece, thereby removing unnecessary parts.

On the other hand, a cutting tool refers to a cutting tool, a cutting tool, a milling machine, a drilling machine, and other cutting tools.

Here, the end mill is a rotary cutting tool widely used for milling, and its outer shape is similar to that of a drill tip, but since the drill tip is used for drilling, the bottom and side of the drill tip form a cutting edge. Side machining is possible.

As shown in Figs. 1 and 2, the end mill includes a solid type (see Fig. 1) in which the cutting edge portion and the body or the bag are made of one tool material according to the manufacturing form, (See Fig. 2).

As shown in FIG. 1, the end mill of the solid type may be a flat end mill, a ball end mill, a taper flat end mill, , Taper Ball Endmill, Raughing Endmill, and Corner Radius Endmill.

As shown in Fig. 1 (a), the flat end mill is most widely used and has the largest number of kinds. The flat end mill can be used for grooving, side processing, and surface processing, .

As shown in Fig. 1 (b), the ball end mill is mainly used for curved surface machining and imitation machining, and since the chip pocket at the center portion is small, the cutting endurance is insufficient compared with other end mills.

As shown in Fig. 1 (c), the tapered flat end mill is used mainly for machining of a recessed portion of a mold and a socket portion, and is mainly used for tapering after machining into a flat end mill.

The paper ball end mill is an end mill having the characteristics of the ball end mill and the taper flat end mill as shown in Fig. 1 (d).

As shown in Fig. 1 (e), the cutting edge of the rough end mill is suitable for roughing (rough machining) because the cutting edge is broken and the chip is cut small and the cutting resistance is small, but the machined surface is rough and suitable for finishing After machining, additional finishing and finishing should be performed using flat end mill or ball end mill.

As shown in Fig. 1 (f), the corner radius end mill is mainly used for curvature machining of a corner portion of a workpiece with an end mill having a small curvature at the blade edge, Diameter endmill can be used to enhance the machining efficiency.

3 (a), the workpiece 10 having the planar work surface 11 is machined by using the flat end mill 50 as shown in Fig. 4 And the ball end mill 60 as shown in Fig. 5 is mainly used for machining of the workpiece 20 having the curved machined surface 21 as shown in Fig. 3 (b).

However, in the case of the blank 30 in which the protruding portion 22 protruded to form the groove sipe or the like is formed on the curved surface portion 21 having the predetermined curvature like the vulcanization mold for tire production of Fig. 3 (c) Considering the portion where the curved surface portion 21 and the protruding portion 22 meet, the corner endless mill shown in FIG. 1 (f) is used instead of the ball end mill 60 as shown in FIG. .

However, when the curved surface portion 21 having the predetermined curvature of the workpiece 30 shown in Fig. 3 (c) is machined using the corner radius end mill, the surface of the curved surface portion 21 cut as shown in Fig. 6 There is a problem that scratches like the one shown in Fig. 7 remain on the surface of the post-processing material (see Fig. 13 comparative photographs).

In order to solve the above problems, an object of the present invention is to provide a rotary type cutting tool in which a bottom surface of a cutting edge portion of a solid type end mill is formed so as to protrude convexly with a predetermined curvature, The cutting edges are rounded with predetermined curvatures to reduce the cutting edge of the cutting tool left on the work surface when cutting the curved portion of the workpiece to obtain a more smooth and excellent processed surface. Tool.

According to another aspect of the present invention, there is provided a rotary cutting tool for use in cutting a curved surface portion, wherein a bottom surface of the rotary cutting tool is formed with a predetermined curvature, And an edge portion formed by the bottom surface and the continuous side surface is rounded to have a predetermined corner curvature.

Here, the rotary cutting tool may be an end mill mounted on a milling machine, and the end mill may be a solid type integrally formed with a body for mounting the milling machine together with the cutting edge.

In addition, it is preferable that the diameter of the rotary cutting tool is within a range of 2 mm to 4 mm.

The bottom curvature of the rotary cutting tool is preferably within a range of 80 mm to 120 mm.

The corner curvature of the rotary cutting tool is preferably within a range of 0.2 mm to 0.5 mm.

The present invention relates to a rotary cutting tool for cutting a curved portion of a cutting tool according to the present invention, wherein the cutting tool has a bottom surface formed with a bottom edge on a side surface of a cutting edge portion, And the side edges of the bottom surface and the side edges of the bottom surface are rounded with predetermined corner curvature so that the curved surface portion of the workpiece having the protruding portion is reduced by reducing the cutting tool transferring marks left on the workpiece surface during cutting It is possible to obtain a more smooth and excellent processed surface.

Particularly, by forming the diameter of the rotary cutting tool within the range of 2 mm to 4 mm, it is possible to minimize the interference of the curved surface of the workpiece with the range of the tool tool diameter that can be used in the finishing work, and the bottom curvature of the rotary cutting tool is within the range of 80 mm to 120 mm The distance between the curved point of the concave portion and the imaginary flat bottom surface is prevented from exceeding the range of 0.01 mm to 0.02 mm so as to prevent the cutting from occurring beyond the workpiece curvature to be machined, Is formed within a range of 0.2 mm to 0.5 mm so that corner portions between the curved surface portion and the protruding portion can be machined more angularly and the contact area between the tool and the workpiece is widened so that the load concentrated at the tool edge is dispersed, And the wear of the cutting tool can be reduced.

FIG. 1 is a photograph showing a conventional solid type end mill.
2 is a photograph showing a conventional insert-type end mill.
Fig. 3 is a view showing a machined surface shape of the workpiece.
Fig. 4 is a side cross-sectional view showing a cutting end of a flat end mill in the conventional solid type of Fig. 1;
5 is a side cross-sectional view showing a state of cutting a ball end mill in the conventional solid type of FIG.
FIG. 6 is a side cross-sectional view showing a state of a surface cutting process using a corner-relief endmill in the conventional solid type of FIG. 1. FIG.
FIG. 7 is a side cross-sectional view showing a shape of a tool transferring station left in a curved portion cutting operation using the conventional corner redissue end mill of FIG. 6;
8 is a side view showing a rotary cutting tool for curving according to an embodiment of the present invention.
Fig. 9 is a front view showing a bottom surface of a cutting edge portion of a rotary cutting tool for curved surface machining in Fig. 8; Fig.
10 is a side view of a cutting edge portion of a rotary cutting tool for curved surface machining in Fig.
11 is an enlarged cross-sectional view taken along the line X-X in Fig. 10.
Fig. 12 is a side cross-sectional view showing a cutting machining state of a rotary cutting tool for curved surface machining in Fig. 8;
Fig. 13 is a comparative photograph showing a machining surface using a rotary cutting tool for curved surface machining of the present invention and a conventional corner redissue end mill.
14 is a comparative photograph showing a wear state of a conventional corner redissue end mill and a rotary cutting tool for curved surface machining according to the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are denoted by the same reference numerals throughout the specification.

FIG. 8 is a side view showing a rotary cutting tool for curved surface machining according to an embodiment of the present invention, FIG. 9 is a front view showing a bottom surface of a cutting edge portion of a rotary cutting tool for curved surface machining in FIG. 8, 10 is a side view of the cutting edge portion of the rotary cutting tool for the curved surface machining of Fig. 8, and Fig. 11 is an enlarged sectional view of the side cut along the line X-X of Fig.

8 to 11, a rotary cutting tool 100 (hereinafter referred to as a rotary cutting tool) for curved surface machining in this embodiment includes a cutting edge portion 110 in which silver cutting edges are formed and a chuck And a body portion 120 for engaging and fixing through an end portion of a solid type end mill integrally formed by using one tool material.

In the rotary cutting tool 100 of the present embodiment, the cutting edges 111 of the cutting edge 110 have four number of flutes and a predetermined helical angle with respect to the center line (axial line) And the inclined plane of the outer peripheral blade is formed to have a predetermined outer peripheral inclination angle (Rake Angle) with a virtual center line when viewed from the front side of the base 112, The radial primary relief portion and the radial secondary ridlid portion constituting the second take-off angle are provided, and a flute is easily provided between the cutting edges to easily discharge chips generated during cutting. do.

The base 112 formed on the bottom surface is inclined at an end rake angle with respect to the center line of the end mill. The first inclined base first margin It is formed with an End Teeth Primary Relife and an inclined Second Teeth Secondary Relife the next day of the first.

11, the lower cutting edge 115 of the rotary cutting tool 110 according to the present embodiment is formed so that the bottom surface 115 on which the tread on the side surface is formed is recessed so as to protrude convexly with a predetermined curvature R1. And an edge corner portion 170 formed by the bottom surface 115 and the continuous side surface 116 on the side surface is rounded with a predetermined corner curvature R2.

In other words, the rotary cutting tool 100 of the present embodiment has an arbitrary hypothetical line passing through both ends of the base to prevent friction between the lower end of the end mill and the work surface of the workpiece 30 (see FIG. 3) The bottom surface 115 is formed so as to be concave so as to protrude convexly with a predetermined bottom curvature, and the bottom surface 115 is formed so as to be continuous with the bottom surface 115 The edge corner portion 170 formed by the blade surface 116 is rounded with a predetermined corner curvature R2 so that the cutting edge of the tool conveying trailing edge of the tool conveying trailing edge Reduce the amount so that a more smooth and excellent surface can be obtained.

Therefore, the rotary cutting tool 100 of the present invention is formed such that the workpiece 30 protrudes convexly on the bottom surface 115 so as to obtain a smooth and excellent processed surface, as described above, As long as the edge corner portion 170 is formed round, the number of teeth, the outer circumference inclination angle, the outer circumference first allowance angle, the outer circumference second allowance angle, the land width, the groove, the twist angle, And the second allowance angle can be variously changed according to the cutting characteristics of the workpiece.

The diameter of the rotary cutting tool 100 of the present embodiment is formed to be within a range of 2 mm to 4 mm in order to obtain a more smooth and excellent processed surface in the curved surface working, the bottom curvature is formed within a range of 80 mm to 120 mm, It is preferable that a corner curvature is formed within a range of 0.2 mm to 0.5 mm. For example.

That is, in the case of roughing and machining at the time of machining the curved surface of the workpiece 30 using the rotary cutting tool 100, a machining allowance that leaves more margin than the actual machining amount is applied, Do not.

Therefore, it is more effective to form the diameter D of the rotary cutting tool 100 within the range of 2 mm to 4 mm so as to minimize the interference of the curved surface of the workpiece, while being within the range of the tool diameter available for finishing.

If the diameter D of the rotary cutting tool 100 is less than 2 mm, the rigidity is low and frequent breakage occurs during machining. If the diameter D is more than 4 mm, the tool has a flat section, It has a drawback that the area of curvature that can be machined is reduced.

Further, when concave grooves are formed so as to protrude convexly with a predetermined curvature R1 on the bottom surface of the rotary cutting tool 100, a distance between the curvature of the concave portion of the protrusion and the imaginary flat bottom surface It is more effective to form the bottom curvature R1 of the rotary cutting tool within the range of 80 mm to 120 mm such that the distance L (hereinafter referred to as the distance value) does not exceed 0.01 mm to 0.02 mm.

When the bottom curvature R1 of the rotary cutting tool 100 is less than 80 mm, the distance L is less than 0.01 mm, so that there is no difference from the use of the conventional corner radial end milled product, The distance L between the workpiece and the workpiece is greater than 0.02 mm, which causes the cutting to occur more than the curvature of the workpiece to be machined.

The corner curvature R2 formed at the edge corner portion 170 formed by the lower blade surface 115 of the rotary cutting tool 100 and the continuous side surface 116 of the rotary cutting tool 100 is larger than the curvature portion 21 of the workpiece 30, And the curved shape of the portion where the protrusion 22 meets.

Therefore, the corner curvature R2 of the rotary cutting tool 100 is set such that the inner curved surface portion 21 having the protruding portion 22 is shaped like a tire vulcanizing mold, It is more effective to form it roundly within a range of 0.2 mm to 0.5 mm so that it can be optimized for making the two-dimensional image.

Fig. 12 is a side cross-sectional view showing a cutting cutting state of a rotary cutting tool for curved surface machining in Fig. 8, Fig. 13 is a side sectional view showing a state in which a rotary cutting tool for machining a curved surface according to the present invention and a machined curved surface using a conventional corner radial end mill FIG. 14 is a comparative photograph showing a wear state of a conventional corner redissue end mill and a rotary cutting tool for curved surface machining according to the present invention.

12 to 14, the rotary cutting tool 100 according to the present embodiment has a bottom surface 115 of a cutting edge portion formed in a concave shape so as to protrude convexly with a predetermined bottom curvature R1, So that the area of contact of the rotary cutting tool 100 with the workpiece 30 is wider than that during the cutting of the curved surface using the conventional corner redissue end mill of Fig. 7, It is possible to obtain a more smooth and excellent processed surface by reducing the amount of the tool transferring station.

13 (a) is a photograph of the cutting state of the curved surface portion 21 of the workpiece 30 using the rotary cutting tool 100 of the present embodiment. FIG. 13 (b) The cutting condition of the curved surface portion 21 of the used workpiece 30 is photographed.

13 (a) and 13 (b), when the curved surface portion 21 is cut using the rotary cutting tool 100 of the present embodiment, It can be seen that a more smooth and excellent processed surface can be obtained.

In addition, in the rotary cutting tool 100 of the present embodiment, the edge corner portion 170 formed by the bottom surface 115 and the continuous side surface 116 is rounded so that the corner portion between the curved surface portion and the protruding portion is more The load concentrated on the edge of the rotary cutting tool 100 is dispersed more than during the cutting of the curved surface using the conventional corner redissue end mill shown in FIG. 7, so that the wear of the rotary cutting tool can be reduced do.

14 (a) is a photograph of the abrasion state of the end of the rotary cutting tool 100 of the present embodiment, and FIG. 14 (b) is a photograph of the abrasion state of the end of the rotary cutting tool 100 in the same curved surface cutting condition as that of the rotary cutting tool 100 of the present embodiment And Fig. 8 is a photograph showing a wear state of the conventional corner redissue end mill used.

14 (a) and 14 (b), it can be seen that the rotary cutting tool 100 of the present embodiment is less worn than the conventional corner redissued end mill.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention. And it goes without saying that they belong to the scope of the present invention.

21: curved portion 22:
30: Workpiece 100: Rotary cutting tool
110: cutting edge part 111: cutting edge
112: base blade 115: bottom blade
116: side surface 120:
D: Diameter L: Distance value between
R1: bottom curvature R2: corner curvature

Claims

A rotary cutting tool used for curved surface cutting,

The rotary cutting tool comprises:
Wherein a bottom surface, on which a base is formed on a side surface of a cutting edge portion, is formed to be concave to protrude convexly with a predetermined curvature,
Wherein a corner edge portion formed by the bottom surface and the continuous side surface on the side surface is rounded with a predetermined corner curvature.

The method of claim 1,
The rotary cutting tool comprises:
An end mill mounted on a milling machine,

In the end mill,
And a body portion for mounting the milling machine together with the cutting edge portion is formed integrally with the rotary cutting tool.

3. The method of claim 2,
Wherein the diameter of the rotary cutting tool is within a range of 2 mm to 4 mm.

4. The method of claim 3,
Wherein the bottom curvature of the rotary cutting tool is within a range of 80 mm to 120 mm.

5. The method of claim 4,
Wherein the corner curvature of the rotary cutting tool is within a range of 0.2 mm to 0.5 mm.