Unequal lead radius end mill

Abstract

To provide an unequal lead radius end mill that is configured so that chatter vibration of a radius part can be suppressed, even in processing difficult-to-cut materials such as stainless steel.SOLUTION: An unequal lead radius end mill 10 comprises four bottom blades 1A, 1B, 1C and 1D, four curved blades 2A, 2B, 2C and 2D formed in succession to the four bottom blades 1A, 1B, 1C and 1D, and four side peripheral blades formed in succession to the four curved blades 2A, 2B, 2C and 2D. Relief angles are formed at the curved blades 2A, 2B, 2C and 2D. The relief angles are gradually increased in a range of 0°-4° from the bottom blades 1A, 1B, 1C and 1D sides toward the side peripheral blades.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a variable lead radius end mill for performing milling such as side machining and groove machining on metal materials and the like. [Background technology]

[0002] Conventionally, in order to suppress chatter vibrations that occur during cutting, so-called unequal lead end mills, in which the helix angles of the end mill side peripheral cutting edges are different, have been used. In addition, end mills with small clearances on the cutting edge ridges have also been used (see Patent Documents 1 to 5). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-118826 [Patent Document 2] Patent No. 6967516 [Patent Document 3] Special Publication No. 7-90410 [Patent Document 4] JP 2023-54484 A [Patent Document 5] International Publication No. 2006-046278 Brochure Summary of the Invention [Problem to be solved by the invention]

[0004] However, when using a variable lead radius end mill to machine difficult-to-cut materials such as stainless steel, chatter vibrations at the radius portion, which is a curved cutting edge, can increase the surface roughness of the workpiece.

[0005] Therefore, an object of the present invention is to provide a unequal lead radius end mill that can suppress chatter vibration in the radius section even when machining difficult-to-cut materials such as stainless steel. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the unequal lead radius end mill of the present invention is an unequal lead radius end mill having two or more bottom blades, curved blades formed continuously from these bottom blades, and blade side blades formed continuously from these curved blades, in which a clearance angle is provided on the curved blade and the clearance angle gradually increases in the range of 0° to 4° from the bottom blade side toward the side blade.

[0007] The side cutting edge may also be provided with a clearance angle in the range of 2° to 4°. In this case, the width of the clearance angle of the side cutting edge may be in the range of 0.02 mm to 0.10 mm when viewed in a cross section perpendicular to the axis. Effect of the Invention

[0008] The unequal lead radius end mill of the present invention has the effect of suppressing chatter vibrations in the radius portion even when cutting difficult-to-cut materials such as stainless steel. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of a variable lead radius end mill 10 of the present invention. [Diagram 2] FIG. 2 is a right side view of the unequal lead radius end mill 10 of the present invention. [Diagram 3] 2 is a cross-sectional view taken along line XX of the variable lead radius end mill 10 shown in FIG. [Figure 4] 3 is a cross-sectional view taken along line YY of the variable lead radius end mill 10 shown in FIG. 2. [Diagram 5] 5 is a schematic enlarged view of a side peripheral blade 3A shown in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] An embodiment of the unequal lead radius end mill 10 of the present invention will be described with reference to the drawings. FIG. 1 shows a front view of the unequal lead radius end mill 10 of the present invention, and FIG. 2 shows a right side view thereof. As shown in FIG. 1 and FIG. 2, the unequal lead radius end mill 10 of this embodiment has four bottom cutting edges 1 (1A, 1B, 1C, 1D), four curved cutting edges 2 (2A, 2B, 2C, 2D) formed continuously to these four bottom cutting edges 1, and four side cutting edges 3 (3A, 3B, 3C, 3D) formed continuously to these four curved cutting edges 2 along the longitudinal direction (axial direction) of the unequal lead radius end mill 10. In addition, in the unequal lead radius end mill 10 of this embodiment, the twist angles of the adjacent side cutting edges 3A, 3B, 3C, 3D are different from each other, forming a so-called unequal lead.

[0011] Furthermore, four twisted grooves (helical grooves) 8 (8A, 8B, 8C, 8D) are formed along the rotation axis O on the front side of each side cutting edge 3 (3A, 3B, 3C, 3D), i.e., on the front side in the rotation direction of the unequal lead radius end mill 10. The helical grooves 8 (8A, 8B, 8C, 8D) may have two or more helical grooves with different radii of curvature when viewed in a cross section perpendicular to the axis of the unequal lead radius end mill 10 as shown in FIG.

[0012] Next, the clearance angle of the cutting edge of the unequal lead radius end mill 10 shown in Figures 1 and 2 will be described with reference to the drawings. Figure 3 shows a cross section of the curved edge 2A of the unequal lead radius end mill 10 shown in Figure 1 taken along line XX, Figure 4 shows a cross section of the unequal lead radius end mill 10 shown in Figure 2 taken along line YY, and Figure 5 shows a schematic enlarged view of the peripheral side edge 3A of the unequal lead radius end mill 10 shown in Figure 4. The curved edge 2A is provided with a clearance angle θ1 adjacent to the clearance face 4A and the rake face 5A as shown in Figure 3.

[0013] The clearance angle θ1 of the curved blade 2A gradually increases in the range of 0° to 4° from the bottom blade 1A side toward the side blade 3A. That is, the clearance angle of the curved blade 2A adjacent to the bottom blade 1A is 0°, and the clearance angle θ1 increases as it approaches the side blade 3A, and finally the clearance angle of the curved blade 2A adjacent to the side blade 3A is 4°. The width (dimension) L1 of the clearance angle θ1 is preferably in the range of 0.02 mm to 0.10 mm.

[0014] The side cutting edge 3A is provided with a clearance angle θ2 adjacent to the clearance face 6A and the rake face 7A as shown in Figures 4 and 5, and the range of the angle θ2 is set to 2° or more and 4° or less. In this case, it is desirable that the width L2 of the clearance angle θ2 of the side cutting edge 3A is set to a range of 0.02 mm or more and 0.10 mm or less when viewed in a cross section perpendicular to the axis of the unequal lead radius end mill 10. The clearance angle θ2 of the side cutting edge 3A is based on a tangent to a virtual circumscribing circle C0 of the unequal lead radius end mill 10 that passes through the cutting edge of the side cutting edge 3A, and the width L2 of the clearance angle θ2 is based on a virtual line connecting the rotation axis O (see Figure 2) of the unequal lead radius end mill 10 and the cutting edge of the side cutting edge 3A.

[0015] With the above-described configuration, the unequal lead radius end mill of the present invention has the effect of suppressing chatter vibration even when cutting difficult-to-cut materials such as stainless steel. [Explanation of symbols]

[0016] 1(1A~1D) Bottom blade 2(2A~2D) Curved blade 3(3A~3D) Side peripheral blade 4A,6A~6D Flank 5A, 7A~7D Rake face 8(8A~8D) Groove 10 Unequal lead radius end mill C0 Virtual circumscribing circle L1 Width of the clearance angle of the curved edge L2 Width of clearance angle of side cutting edge O Rotation axis θ1 Clearance angle of curved edge θ2 Clearance angle of the side edge

Claims

1. This unequal lead radius end mill has a plurality of bottom blades, a plurality of curved blades formed contiguous to the bottom blades, a plurality of side blades formed contiguous to the curved blades, and a plurality of twist grooves formed adjacent to the side blades, and in which the twist angles of adjacent side blades are different from each other, the curved blades are provided with a clearance angle, and the clearance angle gradually increases in the range of 0° to 4° from the bottom blade side toward the side blades.

2. 2. The variable lead radius end mill according to claim 1, wherein the peripheral cutting edge is provided with a clearance angle, the clearance angle being in the range of 2 degrees to 4 degrees.

3. The variable lead radius end mill according to claim 2, characterized in that the width of the clearance angle of the side peripheral cutting edge is in the range of 0.02 mm to 0.10 mm when viewed in a cross section perpendicular to the axis.

4. The variable lead radius end mill according to any one of claims 1 to 3, characterized in that the spiral flute has two or more spiral flutes having different radii of curvature when viewed in a cross section perpendicular to the axis of the variable lead radius end mill.

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