End mill

Abstract

To efficiently perform face milling, side milling or the like on a material to be cut by an end mill, and to prevent breakage of an outer peripheral cutting edge and a boundary part between a tip cutting edge and the outer peripheral cutting edge during cutting.SOLUTION: In the end mill having an arc-shaped tip end cutting edge 11 extending in a radial direction and having a convex center part and arc-shaped outer peripheral cutting edges 12 provided on both sides of the tip end cutting edge in a radial direction at a tip end part of a tool body 10, a center part of the outer peripheral cutting edge is formed in an arc shape so as to bulge outward in a radial direction from the tip end cutting edge, and an outer diameter D1 of the bulged outer peripheral cutting edge is larger than a neck diameter D2 of the tool body. The tip edge and the outer peripheral edge are connected by a circular arc-shaped connecting edge 13 in contact with the tip edge and the outer peripheral edge, the radius of curvature R1 of the tip edge is in a range of 3 / 4 to 1.5 times the outside diameter D1 of the outer peripheral edge, and the radius of curvature R2 of the outer peripheral edge is smaller than the radius of curvature R1 of the tip edge.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] BACKGROUND 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 workpieces.

[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 is arc-shaped and extends radially perpendicular to the central axis with a convex central portion, and spiral peripheral cutting edges are provided on both radial sides of the tip cutting edge, each of which is 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 cutting edge, and the side cutting is performed by the spiral-shaped peripheral cutting edge.

[0005] Here, in the end mill shown in Patent Document 1, a spiral peripheral blade is provided that is 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, performing side cutting, which results in a large load being applied to the spiral peripheral blade, causing problems such as damage to the peripheral blade. [Prior art documents] [Patent documents]

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

[0007] The present invention aims to solve the above-mentioned problems that arise when cutting a workpiece using an end mill that has, 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 that are provided on both radial sides of the tip blade.

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

[0009] In order to solve the above-mentioned problems, the end mill of the present invention has an end mill having an arc-shaped tip cutting edge at the tip of the tool body, which extends radially and has a convex central portion, and arc-shaped peripheral cutting edges provided on both radial sides of the tip cutting edge, wherein the central portion of the peripheral cutting edge is formed in an arc shape so that it bulges radially outward more than the tip cutting edge, and the outer diameter D1 of the bulged peripheral cutting edge is larger than the neck diameter D2 of the tool body, and the tip cutting edge and peripheral cutting edge are connected by an arc-shaped connecting edge that contacts them, and the radius of curvature R1 of the tip cutting edge is in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral cutting edge, and the radius of curvature R2 of the peripheral cutting edge is smaller than the radius of curvature R1 of the tip cutting edge.

[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 bulged 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 conventional cases where the spiral-shaped 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 between the tip blade and peripheral blade, which prevents the connection 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 central portion to a 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.

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

[0014] Furthermore, in the end mill of the present invention, if the radius of curvature R2 of the peripheral cutting edge is in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge, the axial length of the tool body at the peripheral cutting edge can be shortened as described above, 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 set in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral cutting edge, the tool body will not come 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. [Effects 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 that it bulges radially outward more than the tip cutting edge, and the outer diameter D1 of the bulging peripheral cutting edge is made larger than the neck diameter D2 of the tool body.When the tip cutting edge performs face milling on the workpiece and the peripheral cutting edge 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 cutting edge that bulges radially outward more than the tip cutting edge, thereby preventing damage to the peripheral cutting edge.

[0017] Furthermore, if 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 the workpiece as described above, a load is applied to the connection between the tip blade and peripheral blade, which prevents the connection from being damaged.

[0018] Furthermore, by setting the radius of curvature R1 of the arc-shaped tip cutting edge with a convex center to a 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] Furthermore, if the radius of curvature R2 of the peripheral cutting edge is smaller than the radius of curvature R1 of the tip cutting edge, when the central portion of the peripheral cutting edge is configured to bulge radially outward more than the tip cutting edge, the axial length of the tool body at the peripheral cutting edge can be shortened and the load applied to the peripheral cutting edge during side milling can be reduced. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic side view showing the state of the tip of the end mill according to the embodiment of the present invention. [Figure 2] FIG. 2 is a schematic explanatory diagram showing the state of the tip of the end mill in the embodiment. [Figure 3] This is a partially enlarged explanatory diagram showing the state in which the tip cutting edge and the peripheral cutting edge are connected continuously by an arc-shaped connecting edge in the end mill in this embodiment. [Figure 4] FIG. 2 is a schematic perspective view showing the state of the tip of the end mill in the embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

[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 following embodiment, and can be appropriately modified within the scope of the present invention.

[0022] As shown in Figures 1 to 4, the end mill in this embodiment has an arc-shaped tip cutting edge 11 at the tip of the tool body 10, which extends radially and has a convex center, and arc-shaped peripheral cutting edges 12 are provided on both radial sides of the tip cutting edge 11, and the tip cutting edge 11 and the peripheral cutting edges 12 on both sides are connected by arc-shaped connecting edges 13 that contact the tip cutting edge 11 and the peripheral cutting edge 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 more than the tip cutting edges 11, and as shown in Fig. 2, the outer diameter D1 of the bulging peripheral cutting edges 12 is larger than the neck diameter D2 of the tool body 10. In the end mill of this embodiment, the neck diameter D2 of the tool body 10 is set in the range of 0.8 to 0.97 times the outer diameter D1 of the bulging peripheral cutting edges 12, preventing a decrease in the rigidity of the tool body 10.

[0024] In the end mill of this embodiment, the radius of curvature R1 of the tip cutting edge 11 is set to be 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 is set to be in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge 12.

[0025] Here, if the radius of curvature R2 of the peripheral cutting edge 12 is made smaller than the radius of curvature R1 of the tip cutting edge 11 as described above and is in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge, when the central portion of the peripheral cutting edge 12 is configured to bulge radially outward more than the tip cutting edge 11, the axial length of the tool body 10 at the peripheral cutting edge 12 can be shortened, and the load applied to the peripheral cutting edge 12 during side milling 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 and the tip cutting edge 11 performs front cutting and the peripheral cutting edge 12 performs side cutting of the workpiece, the side of the workpiece is cut by the part of the peripheral cutting edge 12 that bulges radially outward from the tip cutting edge 11, so that the entire peripheral cutting edge 12 is not constantly under load, and damage to the peripheral cutting edge 12 is suppressed.

[0028] Furthermore, as described above, the outer diameter D1 of the bulging peripheral cutting edge 12 is larger than the neck diameter D2 of the tool body 10, so the tool body 10 does not come into contact with the side of the workpiece during side cutting.Furthermore, 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, so 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: Connecting 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, at the tip of the tool body, an arc-shaped tip cutting edge that extends radially and has a convex central portion, and arc-shaped peripheral cutting edges provided on both radial sides of the tip cutting edge, wherein the central portion of the peripheral cutting edge is formed in an arc shape so that it bulges radially outward more than the tip cutting edge, the outer diameter D1 of the bulged peripheral cutting edge is larger than the neck diameter D2 of the tool body, the tip cutting edge and the peripheral cutting edge are connected by an arc-shaped connecting edge that contacts them, the radius of curvature R1 of the tip cutting edge is in the range of 3 / 4 to 1.5 times the outer diameter D1 of the peripheral cutting edge, and the radius of curvature R2 of the peripheral cutting edge is smaller than the radius of curvature R1 of the tip cutting edge.

2. 2. The end mill according to claim 1, wherein the radius of curvature R2 of the peripheral cutting edge is in the range of 0.17 to 0.4 times the outer diameter D1 of the peripheral cutting edge.

3. An end mill according to claim 1 or claim 2, 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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