End Mills

Abstract

To provide an end mill that can efficiently perform face milling, side milling, etc., on a workpiece, and also prevents damage to the peripheral blade and the boundary between the tip blade and the peripheral blade during cutting. [Solution] In an end mill having, at the tip of a tool body 10, an arc-shaped tip blade 11 that extends radially with a convex central portion, and arc-shaped peripheral blades 12 provided on both radial sides of the tip blade, the central portion of the peripheral blade is formed in an arc shape so that it bulges radially outward more than the tip blade, and the outer diameter D1 of the bulging peripheral blade is made larger than the neck diameter D2 of the tool body, and the tip blade and peripheral blade are connected by an arc-shaped connecting blade 13 that contacts the tip blade and peripheral blade, the radius of curvature R1 of the tip blade is in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral blade, and the radius of curvature R2 of the peripheral blade is smaller than the radius of curvature R1 of the tip blade.

Description

[Technical field]

[0001] The present invention relates to an end mill having an arc-shaped tip blade at the tip of the tool body, which extends in a radial direction perpendicular to the central axis and has a convex central portion, and arc-shaped peripheral blades provided on both radial sides of the tip blade. In particular, the present invention is characterized in that the end mill can be used to efficiently perform front cutting (flat surface processing) and side cutting (vertical wall surface processing) on ​​a workpiece, while preventing damage to the peripheral blade and the boundary between the tip blade and the peripheral blade during cutting. [Background technology]

[0002] 2. Description of the Related Art Conventionally, end mills such as those shown in Patent Document 1 have been used to perform face milling, side milling, and the like on a workpiece.

[0003] Here, in the end mill shown in Patent Document 1, a tip cutting edge is provided at the tip of the tool body, which extends in a radial direction perpendicular to the central axis and has an arc-shaped convex central portion, and spiral peripheral cutting edges are provided on both radial sides of the tip cutting edge so as to be continuous with the tip cutting edge.

[0004] When the end mill shown in Patent Document 1 is used to cut a workpiece, generally, the front cutting is performed by the arc-shaped tip blade, and the side cutting is performed by the spiral peripheral blade.

[0005] Here, in the end mill shown in Patent Document 1, a spiral peripheral blade is provided so as to be continuous with the tip blade as described above, and the spiral peripheral blade is always in contact with the side of the workpiece being cut to perform side cutting, which results in a large load being applied to the spiral peripheral blade, causing problems such as breakage of the peripheral blade. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. WO2020 / 166421 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0007] The present invention aims to solve the above-mentioned problems that occur when cutting a workpiece using an end mill having, at the tip of the tool body, an arc-shaped tip blade that extends radially perpendicular to the central axis and has a convex central portion, and arc-shaped peripheral blades provided on both radial sides of the tip blade.

[0008] In other words, the present invention aims to use an end mill as described above to efficiently perform face cutting (flat surface processing) and side cutting (vertical wall surface processing) on ​​a workpiece, while preventing damage to the outer blade and the boundary between the tip blade and the outer blade during cutting. [Means for solving the problem]

[0009] In the end mill of the present invention, in order to solve the above-mentioned problems, the tip of the tool body has an arc-shaped tip blade that extends in the radial direction and has a convex central portion, and arc-shaped peripheral blades provided on both radial sides of the tip blade, and the central portion of the peripheral blade is formed in an arc shape so as to bulge outward in the radial direction more than the tip blade, and the outer diameter D1 of the bulged peripheral blade is is the diameter of the neck portion which is small in diameter at the rear of the peripheral cutting edge and parallel to the axial direction of the tool body. The diameter is larger than the neck diameter D2, and the tip blade and the peripheral blade are connected by an arc-shaped connecting blade that contacts the tip blade and the peripheral blade, and the radius of curvature R1 of the tip blade is in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral blade, and the radius of curvature R2 of the peripheral blade is smaller than the radius of curvature R1 of the tip blade and in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral blade.

[0010] Here, as in the end mill of the present invention, when the central portion of the peripheral blade is formed in an arc shape so as to bulge radially outward more than the tip blade, and the outer diameter D1 of the bulging peripheral blade is larger than the neck diameter D2 of the tool body, when the tip blade performs face milling on the workpiece and the peripheral blade performs side milling on the workpiece, the tool body does not come into contact with the side of the workpiece, and the side of the workpiece is cut by the part of the peripheral blade that bulges radially outward more than the tip blade, which reduces damage to the peripheral blade compared to the conventional case in which the spiral peripheral blade always comes into contact with the side of the workpiece to perform side milling.

[0011] Furthermore, as in the end mill of the present invention, when the tip blade and peripheral blade are connected by an arc-shaped connecting blade that contacts the tip blade and peripheral blade, when performing front and side milling on a workpiece as described above, a load is applied to the connection portion between the tip blade and peripheral blade, which prevents the connection portion from being damaged.

[0012] Furthermore, as in the end mill of the present invention, by setting the radius of curvature R1 of the arc-shaped tip cutting edge with a convex center in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral cutting edge, the cutting resistance during face milling can be reduced while ensuring the amount of cut into the workpiece, making it possible to efficiently perform high-feed machining.

[0013] Furthermore, if the radius of curvature R2 of the peripheral blade is made smaller than the radius of curvature R1 of the tip blade, as in the end mill of the present invention, and the central portion of the peripheral blade is arranged to bulge radially outward more than the tip blade, the axial length of the tool body at the peripheral blade can be shortened and the load applied to the peripheral blade during side cutting can be reduced, making it possible to perform side cutting efficiently.

[0014] Further, the end mill in the present invention Like When the radius of curvature R2 of the peripheral cutting edge is set in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge, the axial length of the peripheral cutting edge of the tool body can be reduced as described above. twistIt can be made shorter and the load applied to the peripheral cutting edge during side milling can be further reduced.

[0015] Furthermore, in the end mill of the present invention, if the neck diameter D2 of the tool body is in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral cutting edge, the tool body can be prevented from coming into contact with the side of the workpiece, as described above, and the side of the workpiece can be cut by the part of the peripheral cutting edge that bulges radially outward more than the tip cutting edge, and it is possible to prevent the neck diameter D2 of the tool body from becoming smaller, thereby preventing a decrease in the rigidity and strength of the tool body. Effect of the Invention

[0016] As in the end mill of the present invention, the central portion of the peripheral cutting edge is formed in an arc shape so as to bulge radially outward from the tip cutting edge, and the outer diameter D1 of the bulged peripheral cutting edge is is the diameter of the neck portion which is small in diameter at the rear of the peripheral cutting edge and parallel to the axial direction of the tool body. By making the neck diameter larger than D2, when the tip blade performs face cutting on the workpiece and the peripheral blade performs side cutting on the workpiece, the tool body does not come into contact with the side of the workpiece, and the side of the workpiece is cut by the part of the peripheral blade that bulges radially outward from the tip blade, thereby preventing damage to the peripheral blade.

[0017] In addition, by connecting the tip blade and the peripheral blade with an arc-shaped connecting blade that contacts the tip blade and the peripheral blade, when performing front and side cutting processes on a workpiece as described above, the connection part between the tip blade and the peripheral blade is prevented from being damaged due to a load being applied to the connection part.

[0018] Furthermore, by setting the radius of curvature R1 of the arc-shaped tip cutting edge with a convex center to the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral cutting edge, the cutting resistance during face milling can be reduced while ensuring the amount of cut into the workpiece, enabling high-feed machining to be performed efficiently.

[0019] In addition, by making the radius of curvature R2 of the peripheral cutting edge smaller than the radius of curvature R1 of the tip cutting edge, when the central portion of the peripheral cutting edge is arranged to bulge radially outward more than the tip cutting edge, the axial length of the peripheral cutting edge of the tool body can be shortened and the load applied to the peripheral cutting edge during side milling can be reduced. Furthermore, by setting the radius of curvature R2 of the peripheral cutting edge to a range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge, the axial length of the peripheral cutting edge of the tool body can be further shortened as described above, and the load applied to the peripheral cutting edge during side milling can be further reduced. do. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic side view showing the state of a tip portion of an end mill according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic explanatory diagram showing the state of the tip of the end mill in the embodiment. [Diagram 3] 1 is a partially enlarged explanatory diagram showing the state in which the tip blade and the peripheral blade are connected so as to be continuous by an arc-shaped connecting blade in the end mill of the same embodiment. FIG. [Figure 4] FIG. 2 is a schematic perspective view showing the state of a tip portion of the end mill in the embodiment. BEST MODE FOR CARRYING OUT THEINVENTION

[0021] Hereinafter, an end mill according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the end mill of the present invention is not limited to the embodiment shown below, and can be appropriately modified without departing from the spirit of the present invention.

[0022] As shown in Figures 1 to 4, the end mill in this embodiment has an arc-shaped tip blade 11 that extends radially and has a convex center at the tip of a tool body 10, and arc-shaped peripheral blades 12 are provided on both radial sides of the tip blade 11, and the tip blade 11 and the peripheral blades 12 on both sides are connected by arc-shaped connecting blades 13 that contact the tip blade 11 and the peripheral blades 12, respectively.

[0023] In the end mill of this embodiment, the central portions of the peripheral cutting edges 12 on both sides are formed in an arc shape so as to bulge radially outward from the tip cutting edge 11, and as shown in FIG. 2, the outer diameter D1 of the bulging peripheral cutting edges 12 is The diameter of the neck portion that is small in diameter at the rear of the peripheral cutting edge 12 and parallel to the axial direction of the tool body 10. In the end mill of this embodiment, the neck diameter D2 of the tool body 10 is set to be in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral cutting edge 12, thereby preventing the rigidity of the tool body 10 from decreasing.

[0024] In the end mill of this embodiment, the radius of curvature R1 of the tip cutting edge 11 is in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral cutting edge 12, and the radius of curvature R2 of the peripheral cutting edge 12 is smaller than the radius of curvature R1 of the tip cutting edge and in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge 12.

[0025] Here, by making the radius of curvature R2 of the peripheral blade 12 smaller than the radius of curvature R1 of the tip blade 11 as described above and within the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral blade, when the central portion of the peripheral blade 12 is arranged to bulge radially outward more than the tip blade 11, the axial length of the tool body 10 at the peripheral blade 12 can be shortened, and the load applied to the peripheral blade 12 during side cutting processing can be reduced.

[0026] When the end mill of this embodiment is rotated and the workpiece is cut with the tip cutting edge 11, the cutting resistance applied to the tip cutting edge 11 during face milling can be reduced while ensuring the amount of cutting into the workpiece by the tip cutting edge 11, thereby enabling efficient high feed machining.

[0027] Furthermore, when the end mill of this embodiment is rotated to perform front cutting with the tip blade 11 and to perform side cutting of the workpiece with the peripheral blade 12, the side of the workpiece is cut by the part of the peripheral blade 12 that bulges radially outward from the tip blade 11, so that the entire peripheral blade 12 is not constantly under load, and damage to the peripheral blade 12 is suppressed.

[0028] In addition, as described above, the outer diameter D1 of the bulging peripheral blade 12 is larger than the neck diameter D2 of the tool body 10, so that the tool body 10 does not hit the side of the workpiece during side cutting.Furthermore, the neck diameter D2 of the tool body 10 is in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral blade 12, so that the rigidity of the tool body 10 is maintained and stable side cutting can be performed. [Explanation of symbols]

[0029] 10: Tool body 11: Tip blade 12: Peripheral blade 13: Joint blade D1: Outer diameter of peripheral cutting edge D2: Neck diameter R1: Radius of curvature of tip R2: Radius of curvature of peripheral cutting edge

Claims

1. An end mill having an arc-shaped tip blade at the tip of a tool body, the tip blade extending in the radial direction and having a convex central portion, and arc-shaped peripheral blades provided on both radial sides of the tip blade, the central portion of the peripheral blade being formed in an arc shape so as to bulge radially outward more than the tip blade, the outer diameter D1 of the bulging peripheral blade being larger than the neck diameter D2 which is the diameter of a neck portion which becomes smaller in diameter at the rear of the peripheral blade and is parallel to the axial direction of the tool body, the tip blade and the peripheral blade being connected by an arc-shaped connecting blade which is in contact with the tip blade and the peripheral blade, the radius of curvature R1 of the tip blade being in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral blade, and the radius of curvature R2 of the peripheral blade being smaller than the radius of curvature R1 of the tip blade and in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral blade.

2. An end mill as described in claim 1, characterized in that the neck diameter D2 of the tool body is in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral cutting edge.

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