End mill

Abstract

To provide an end mill capable of enhancing discharge characteristics of chips generated during cutting work while securing rigidity of an end mill body.SOLUTION: In an end mill having four end cutting edges, four peripheral cutting edges formed continuously to these end cutting edges, and four grooves formed adjacent to these peripheral cutting edges, width of a land of the peripheral cutting edge is changed along a longitudinal direction of the end mill in a cross-sectional view perpendicular to a rotary shaft of the end mill. The width of the land of theses peripheral cutting edges is made wider on a shank side of the end mill than on the end cutting edge side of the end mill.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an end mill for machining the side surface of a workpiece. [Background technology]

[0002] Conventionally, end mills used for groove machining or side machining of workpieces have a constant land width and groove cross-sectional area from the bottom cutting edge side to the shank side, as disclosed in Patent Documents 1 to 3. In addition, the land width and groove cross-sectional area of ​​the end mill can be changed depending on the type of workpiece and machining conditions.

[0003] For example, increasing the land width of the end mill improves the rigidity of the end mill itself, preventing the end mill from tipping over during side machining. Also, increasing the cross-sectional area of ​​the groove (widening the groove width) can prevent chips from clogging the groove during groove machining. A schematic cross-sectional view of a conventional end mill 100 is shown in FIG. 6, a cross-sectional view of the end mill 100 shown in FIG. 6 taken along line XX is shown in FIG. 7, and a cross-sectional view of the end mill 100 shown in FIG. 6 taken along line YY is shown in FIG. 8. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-287114 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-90148 [Patent Document 3] Patent No. 4936495 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the land widths 201 and 202 of the end mill 100 are widened, the groove width becomes narrower, which makes it easier for chips to get stuck in the groove when machining grooves that require chip pockets. On the other hand, if the cross-sectional area of ​​the groove is widened, the land widths 201 and 202 become narrower, which reduces the rigidity of the end mill 100, causing the end mill 100 to lean more when machining side surfaces, resulting in a problem of not being able to improve machining efficiency.

[0006] Therefore, an object of the present invention is to provide an end mill that ensures the rigidity of the end mill body while at the same time improving the discharge characteristics of chips generated during cutting. [Means for solving the problem]

[0007] The end mill of the present invention has a plurality of end cutting edges, a plurality of peripheral cutting edges formed continuously on the end cutting edges, and a plurality of grooves formed adjacent to the peripheral cutting edges, and in a cross section perpendicular to the rotation axis of the end mill, the width of the lands of the peripheral cutting edges is varied along the longitudinal direction of the end mill. Also, the width of the lands of the peripheral cutting edges is wider on the shank side than on the end cutting edge side of the end mill.

[0008] The land of the peripheral cutting edge can also be formed from a first land portion whose width is constant along the axial direction of the end mill, a second land portion whose width changes continuously along the axial direction of the end mill, and a third land portion whose width is constant along the axial direction of the end mill. In this case, the first land portion is formed on the bottom cutting edge side of the end mill, and the third land portion is formed on the shank side of the end mill. [Effects of the Invention]

[0009] The end mill of the present invention has the effect of ensuring the rigidity (of the end mill body) while at the same time improving the discharge characteristics of chips generated during cutting. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic front view of an end mill 10 according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along line AA of the end mill 10 shown in FIG. [Figure 3] 2 is a cross-sectional view of the end mill 10 shown in FIG. 1 taken along the line BB. [Figure 4] 2 is a cross-sectional view of the end mill 10 shown in FIG. 1 taken along line CC. [Figure 5] 2 is a schematic diagram showing a change in the land width of the end mill 10 shown in FIG. 1. [Figure 6] 2 is a schematic diagram showing a change in groove width of the end mill 10 shown in FIG. 1. FIG. [Figure 7] FIG. 1 is a schematic cross-sectional view of a conventional end mill 100. [Figure 8] 7 is a cross-sectional view of the end mill 100 shown in FIG. 6 taken along line XX. [Figure 9] 7 is a cross-sectional view of the end mill 100 shown in FIG. 6 taken along line YY. DETAILED DESCRIPTION OF THE INVENTION

[0011] The end mill of the present invention will be described with reference to the drawings. Fig. 1 shows a schematic front view of an end mill 10 according to one embodiment of the present invention, Fig. 2 shows a cross-sectional view of the end mill 10 shown in Fig. 1 along line AA, Fig. 3 shows a cross-sectional view of the end mill 10 shown in Fig. 1 along line BB, and Fig. 4 shows a cross-sectional view of the end mill 10 shown in Fig. 1 along line CC.

[0012] End Mill 10 1, the end mill 10 of the present invention has four bottom cutting edges 1A-1D at the tip of the end mill 10, four peripheral cutting edges 2A-2D formed continuously with these four bottom cutting edges 1A-1D, and four grooves 3A-3D formed adjacent to these peripheral cutting edges 2A-2D. The bottom cutting edges 1A-1D, peripheral cutting edges 2A-2D, and grooves 3A-3D will be described in detail below.

[0013] 《Bottom Blade》 The four end cutting edges 1A to 1D are cutting edges at the tip of the end mill 10. The end cutting edges 1A to 1D are arranged in equal or unequal divisions in the circumferential direction (rotation direction) around the rotation axis O. The outer ends of the end cutting edges 1A to 1D are continuously connected to the four peripheral cutting edges 2A to 2D, which will be described later.

[0014] 《Peripheral blade》 The four peripheral cutting edges 2A to 2D are formed continuously with the four end cutting edges 1A to 1D described above, and are formed along the axial direction on the outer peripheral surface of the end mill 10. Any adjacent peripheral cutting edges may have either an equal lead, where the lead is constant, or an unequal lead, where the lead is different.

[0015] "groove" The grooves 3A to 3D are helical grooves formed on the front side of the rotation direction of the end mill 10 relative to the four peripheral cutting edges 2A to 2D mentioned above, and the number of grooves in the end mill 10 in this embodiment is four, the same number as the number of teeth on the peripheral cutting edges.

[0016] <Land width of peripheral cutting edge (land width)> Next, the land widths of the four peripheral cutting edges 2A-2D will be described. In the end mill 10 of this embodiment, as shown in Figures 2 to 4, the widths of the lands 4A-4D of the peripheral cutting edges 2A-2D vary along the longitudinal direction of the end mill 10 in a cross-sectional view perpendicular to the rotation axis O of the end mill 10. Figure 5 is a schematic diagram showing the variation in land width of the end mill 10 shown in Figure 1. That is, the widths of the lands 4A-4D of all four peripheral cutting edges 2A-2D of the end mill 10 of the present invention are wider on the shank 20 side of the end mill 10 than on the bottom cutting edges 1A-1D side of the end mill 10.

[0017] Furthermore, in the end mill 10 of this embodiment, the lands 4A-4D of the peripheral cutting edges 2A-2D can be divided into three regions: a first land portion where widths 14A-14D of the lands 4A-4D are constant along the axial direction of the end mill 10; a second land portion where widths 24A-24D of the lands 4A-4D vary continuously along the axial direction of the end mill 10; and a third land portion where widths 34A-34D of the lands 4A-4D are constant along the axial direction of the end mill 10. In this case, the first land portion can be formed on the end mill 10's side of the bottom cutting edges 1A-1D, and the third land portion can be formed on the end mill 10's side of the shank 20.

[0018] The axial length (longitudinal dimension) of the end mill 10 having the first, second, and third land portions can be set arbitrarily. For example, the dimension of the region having the first land portion (longitudinal dimension of the end mill 10) and the dimension of the region having the third land portion (longitudinal dimension of the end mill 10) can be set to approximately the same length (dimension), and the dimension of the region having the second land portion (longitudinal dimension of the end mill 10) can be made shorter than these dimensions.

[0019] Next, the widths of the grooves 3A-3D of the end mill 10 of this embodiment will be described. Fig. 6 is a schematic diagram showing the change in groove width of the end mill 10 shown in Fig. 1. When the four end cutting edges 1A-1D of the end mill 10 of this embodiment are equally spaced, as shown in Figs. 2 to 4, the widths 13A-13D, 23A-23D, and 33A-33D of the grooves 3A-3D also depend greatly on the widths of the lands 4A-4D. That is, as the widths 14A-14D, 24A-24D, and 34A-34D of the lands 4A-4D increase, the widths 13A-13D, 23A-23D, and 33A-33D of the grooves 3A-3D decrease. On the other hand, if the widths 14A to 14D, 24A to 24D, and 34A to 34D of the lands 4A to 4D are narrower, the widths 13A to 13D, 23A to 23D, and 33A to 33D of the grooves 3A to 3D are wider.

[0020] For example, if the widths 34A-34D of the lands 4A-4D of the end mill 10 of this embodiment located on the shank 20 side of the end mill 10 are wider than the widths 14A-14D of the lands 4A-4D located on the bottom cutting edge 1A-1D side of the end mill 10 as shown in Figures 2 and 4, the groove widths 13A-13D of the grooves 3A-3D will be narrower for the grooves 3A-3D located on the shank 20 side of the end mill 10 than the groove widths 13A-13D of the grooves 3A-3D located on the bottom cutting edge D side of the end mill 10.

[0021] Although the end mill of this embodiment has four bottom and peripheral cutting edges and four grooves, the number of bottom and peripheral cutting edges may be two, three, or five or more. The number of grooves may also be two, three, or five or more. [Explanation of symbols]

[0022] 1A~1D bottom blade 2A~2D Peripheral blade 3A~3D Groove 4A~4D Land 10 End mill 13A~13D groove width 14A~14D Land width 20 shank 23A~23D groove width 24A~24D Land width 33A~33D groove width 34A~34D Land width 100 end mill 201,202 Land width O Rotation axis

Claims

1. An end mill having a plurality of bottom cutting edges, a plurality of peripheral cutting edges formed continuously from the bottom cutting edges, and a plurality of grooves formed adjacent to the peripheral cutting edges, characterized in that, when viewed in a cross section perpendicular to the rotation axis of the end mill, the width of the lands of the plurality of peripheral cutting edges is wider on the shank side of the end mill than on the bottom cutting edge side of the end mill.

2. The end mill described in claim 1, characterized in that the land of the peripheral cutting edge is formed from a first land portion in which the width of the land is constant along the axial direction of the end mill, a second land portion in which the width of the land changes continuously along the axial direction of the end mill, and a third land portion in which the width of the land is constant along the axial direction of the end mill.

3. 3. The end mill according to claim 2, wherein the first land portion is formed on the bottom cutting edge side of the end mill, and the third land portion is formed on the shank side of the end mill.

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