JPH0453851Y2 - - Google Patents

Description

[Detailed explanation of the invention] "Industrial application field" This invention is designed to effectively discharge chips.
This relates to an end mill that has a hole formed at its tip to eject air, oil, etc.

“Conventional technology” Traditionally, this type of end mill has a 5th
6, 7 and 8 are known.

The end mill shown in FIGS. 5 and 6 has four spiral peripheral blades 2 formed on the outer periphery of the end mill body 1, and these peripheral blades 2 are formed on the tip surface of the end mill body 1. A series of front cutting blades (cutting blades) 3 each extending toward the center of the tip surface are formed, and further, the end mill body 1
A hole 4 extending from the rear end surface to the distal end surface is formed in the center of the interior of the holder. Above hole 4
is for blowing out air, oil, etc. to discharge chips generated when machining a workpiece material with the end mill, and this hole 4 is opened in the center of the tip surface of the end mill body 1. Therefore, the inner edges of the front cutting blades 3 are located apart from the axis of the end mill body 1.

The ball end mill shown in FIGS. 7 and 8 has four spiral peripheral blades 9 formed on the outer periphery of the end mill body 8, and these peripheral blades 9 formed at the tip of the end mill body 8. A front cutting edge (cutting edge) 10 . A hole 13 extending from the end face toward the tip is formed, and branch holes 14, 14 branching from the tip of the hole 13 are formed. In the above configuration, the branch holes 14, 14
is for spouting air, oil, etc. to discharge chips generated when machining a workpiece with the end mill, and extends in a direction perpendicular to the axis of the hole 13, and extends in the radial direction of the end mill body 8. It opens outward.

``Problem to be solved by the invention'' By the way, in the end mill shown in FIGS. 5 and 6 above, a hole 4 is opened in the center of the front cutting edge 3 of the end mill body 1. Since cutting is not performed in the hole 4, there is a problem in that it is not possible to cut in the axial direction.

In the ball end mills shown in FIGS. 7 and 8, although it is possible to cut in the axial direction, the hole 1 extends to the vicinity of the tip of the end mill body 8.
1 is formed, and when re-sharpening, which is generally required for end mills, the hole 11 comes out at the center of the front cutting edge 10 at the tip of the end mill body 8, so it is practically impossible to re-sharpen. Polishing is not possible;
Moreover, branch holes 14, 1 branched from the hole 13
4 does not face toward the tip of the end mill body 8, so there is a problem in that it is difficult to smoothly discharge chips near the front cutting edge 10.

"Purpose of the invention" This invention was made to solve the above-mentioned problems, and its purpose is to provide an end mill that can smoothly discharge chips, cut in the axial direction, and easily regrind.

"Means for Solving the Problem" This invention has a front cutting edge formed at the tip of a substantially cylindrical end mill body, a spiral outer cutting edge formed on the outer periphery, and a cutting edge inside the end mill body. In the end mill described above, a hole extending from the rear end side to the front end side is formed in the center part, and a branch hole is formed that branches from the front end of this hole and opens at the front end flank of the end mill body. The branch hole is branched from a terminal position of the peripheral blade in the axial direction of the end mill body, and is gradually spaced apart from the axis of the end mill body as it goes from the rear end side to the front end side of the end mill body. It is characterized by the fact that it has been formed.

"Embodiment" FIGS. 1 to 4 are diagrams showing an embodiment of this invention.

FIGS. 1 and 2 are diagrams showing the end mill of the first embodiment, and in the figures, reference numeral 20 indicates the end mill body. The end mill main body 20 has a substantially cylindrical shape, and on its outer periphery, a plurality of (four in the figure) outer circumferential blades 21 are formed spirally along the axial direction. Additionally, these peripheral blades 2 are provided on the tip surface of the end mill body 20.
Front cutting edges (cutting edges) 22 . . . are formed which are continuous with 1 . . . and each extend toward the center of the tip surface. Here, the front cutting edge 22 is formed at the intersection of the rake face 23 and the flank face 24. This flank 24 includes a first flank 24a forming the front cutting edge 22, and a first flank 24a that forms the front cutting edge 22.
and a second flank 24b that is connected to the second flank 24b.

Further, a hole 25 is formed in the center inside the end mill body 20, and extends from the rear end surface of the end mill body 20 toward the tip end to near the end of the outer peripheral blade 21. The second flank faces 24b, 2 are branched in two directions from the part.
4b, branch holes 26, 26 that open at locations spaced apart from the axis of the end mill main body 20 are formed so as to be gradually spaced apart from the axis as they go toward the distal end side. These branch holes 26, 26 are for blowing out air, oil, etc. for discharging chips generated when machining a workpiece with the end mill.

Note that cemented carbide, cermet, etc. are used as the material for the end mill.

According to the end mill having the above configuration, there is a center of the front cutting blade, and branch holes 26, 26 are formed in the second flanks 24b, 24b of the front cutting blades 22, 22 other than the center of the front cutting blade, and the branch holes 26, 26 are formed in the end mill body 20. Since it is formed toward the tip side, it is possible to cut in the axial direction, which was impossible with the conventional end mill shown in FIGS. 5 and 6, and moreover, the front cutting edge 22...
...Cuts in the vicinity can be smoothly discharged.

3 and 4 are diagrams showing a second embodiment, in which this invention is applied to a ball end mill.

In these figures, reference numeral 30 indicates the end mill body. On the outer periphery of this end mill body 30,
A plurality of (four in the figure) peripheral blades 31 are each formed in a spiral shape along the axial direction.
Furthermore, front cutting edges (cutting edges) 32 are formed at the tip of the end mill main body 30, and are connected to the peripheral edges 31 and each extend in an arc shape toward the center of the tip. There is. Here, the front cutting edge 32 is formed at the intersection of the rake face 33 and the flank face 34. This flank 34 includes a second flank 34a forming the front cutting edge 32, and a second flank 34b connected to the first flank 34a.
It is made up of.

Further, a hole 35 is formed in the center inside the end mill body 30, and extends from the rear end surface of the end mill body 30 toward the tip end to near the end of the outer peripheral blade 31. The second flank surfaces 34b, 34b of the front cutting blades 32, 32 branch into two directions from the end mill body 3.
Branch hole 3 that opens at a location apart from the axis of 0
6 and 36 are formed so as to be gradually spaced apart from the axis as they go toward the distal end.

In addition, the materials for the ball end mill mentioned above are:
Similar to the end mill of the first embodiment, cemented carbide, cermet, etc. are used.

According to the ball end mill having the above configuration, since the branch holes 36, 36 face the tip side of the end mill body 30, chips near the front cutting edge 32 at the tip of the end mill body 30 can be smoothly discharged. I can do it. Furthermore, since there is no hole in the center of the tip of the end mill body 30, even if the end mill body 30 is reground, the seventh
Unlike the ball end mills shown in Fig. 8 and Fig. 8, a hole does not appear in the center of the front cutting edge, so regrinding is possible.

In the above embodiment, two branch holes 26 and 36 are each formed, but the invention is not limited to this, and it is sufficient to form at least one branch hole each.

"Effects of the invention" As explained above, according to this invention, a front cutting edge is formed at the tip of the substantially cylindrical end mill body, a spiral peripheral cutting edge is formed at the outer periphery, and the end mill body An end mill comprising: a hole extending from the rear end to the front end in the center of the interior thereof; and a branch hole branching from the front end of the hole and opening into the flank of the end mill body. The branch hole is branched from a terminal position of the peripheral blade in the axial direction of the end mill body, and is gradually spaced apart from the axis of the end mill body as it goes from the rear end side to the tip end of the end mill body. Therefore, air, oil, etc. can be effectively ejected from the branch hole to the tip of the end mill main body, and chips can be smoothly discharged. In particular, since the branch hole is configured to branch from the end position of the outer peripheral cutter in the axial direction of the end mill body, it is possible to increase the cross-sectional area of the tip of the end mill body and strengthen the cutting edge strength. It is economical as the cutting edge can be re-sharpened many times.

[Brief explanation of drawings]

1 to 4 are diagrams showing an embodiment of this invention. 1 and 2 are diagrams showing the first embodiment, and FIG. 1 is a side view of the end mill,
FIG. 2 is a front view of the end mill, FIGS. 3 and 4 are views showing the second embodiment, and FIG. 3 is a front view of the end mill.
FIG. 4 is a front view of the ball end mill, FIGS. 5 and 6 are views showing conventional end mills, FIG. 5 is a side view of the end mill, and FIG. 6 is a side view of the end mill. Front view of end mill,
7 and 8 are views showing a conventional ball end mill. FIG. 7 is a side view of the ball end mill, and FIG. 8 is a front view of the ball end mill. 20, 30... End mill body, 22, 32...
...Front cutting edge (cutting edge), 24, 34...Tip flank,
25, 35... hole, 26, 36... branch hole.

Claims (1)

[Scope of utility model registration request] A front cutting edge is formed at the tip of the approximately cylindrical end mill body, a spiral peripheral cutting edge is formed at the outer periphery, and a hole extending from the rear end toward the tip in the center of the interior of the end mill body. In an end mill in which a branch hole is formed that branches from the tip of the hole and opens at the tip flank of the end mill body, the branch hole extends from the outer peripheral blade in the axial direction of the end mill body. An end mill characterized in that the end mill is formed to branch from a terminal position and to be gradually spaced apart from the axis of the end mill body as it goes from the rear end side to the front end side of the end mill body.