JPH05116018A - End mill - Google Patents

Abstract

PURPOSE:To provide an end mill which is capable of simultaneous rough and finish work when forming a contour of a work, such as a mold or a Jig, by milling. CONSTITUTION:In an end mill which is held in a milling machine and driven to rotate, in a throw-away tip 10 disposed on a spiral groove mounting face formed on the peripheral surface of a cylindrical body, a rough work edge 11 located in front of the rotational direction of the cylindrical body and a finishing edge 12 located behind the edge are formed integrally. The outer flange 11c of the rough work edge 11 is closer to the center of the cylindrical body than the outer flange 12c of the finishing edge 12 and both protrude from the peripheral surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an end mill in which a blade is formed on the outer peripheral surface of a cylindrical body which is rotationally driven by a milling machine.

[0002]

2. Description of the Related Art A milling end mill for contouring is used for rough cutting, as shown in FIG.
The throw-away tip 21 is provided with a screw 22b on the spiral groove-shaped mounting surface 23 on the outer peripheral surface of a along a spiral path having a pitch such that the work surface is machined at any one time during one rotation.
End mills 22 are known which are mounted and arrayed in. On the other hand, for finishing, as shown in FIG. 5B, a scare end mill 25 in which a plurality of spiral cutting blades 26 are formed in a cylindrical body 25a is well known. Thus, as shown in FIG. 6, for example, the square end mill 25 is held by the holder 28 of the milling machine and rotationally driven to process the work 27.

[0003]

That is, when roughing is performed in advance during finishing, it is necessary to replace it with a finishing end mill after the roughing end mill is finished, which not only increases the machining time. Tool costs and management costs are correspondingly high. In view of such a point, the present invention provides an end mill capable of performing rough cutting and finishing at the same time when contouring a workpiece such as a mold or a jig by milling. To aim.

[0004]

The present invention relates to an end mill in which a throwaway tip is arranged on a spiral groove-shaped mounting surface formed on the outer peripheral surface of a cylindrical body which is held by a milling machine and driven to rotate. In order to achieve the purpose of, the throwaway tip is integrally formed from the rough cutting blade located in the front in the rotational direction of the cylindrical body and the finishing blade located behind this blade. The outer edge of is closer to the center of the cylindrical body than the outer edge of the finishing blade, and both are formed to project from the outer peripheral surface.

In order to improve the discharge property of chips, a throwaway tip is used with a rough cutting blade, a finishing blade having an outer shape larger than its outer shape, and an outer shape smaller than these blades.
It is integrally formed coaxially with a boss portion interposed between these blades. In order to efficiently perform the finishing process, the flat front end face of the finishing blade in the rotational direction is partially aligned in the radial direction of the cylindrical body.

[0006]

[Operation] When the cylinder rotates, the rough cutting blade located in the front in the rotation direction cuts the work, and the work surface rough cut behind is finished with the outer edge from the center of the cylinder at a larger radius circle position. Roughing and finishing are performed at the same time by cutting with a blade.

[0007]

1 to 3 show an end mill 1 rotatably driven by a milling machine according to an embodiment of the present invention, in which a plurality of spiral groove-shaped mounting surfaces 3 formed on an outer peripheral surface 1b of a cylindrical body 1a. Further, the throwaway tips 10 are arranged in a spiral shape. This throwaway tip has a central axis A
Roughing blade 11 with a square cross section in the orthogonal direction
And a larger square finishing blade 12, and a boss portion 1 having an outer shape smaller than any of these and intervening in the middle.
It is integrally formed as a two-stage chip in a coaxial manner with that of 3. The rough cutting blade 11 and the finishing blade 12 are provided with flat front end faces 11a and 12a that face the rotation direction C (FIG. 4) of the throwaway tip 10, and the outer shapes gradually decrease rearward. The inclined flanks 11b and 12b are formed. In addition, at the center thereof, the screw through hole 1
5 is formed, and a nick 11d is formed on the peripheral edge of the rough cutting blade 11 to efficiently perform cutting.

In order to mount the throw-away tip 10, the throw-away tip 10 is partially formed in the direction of the central axis B of the cylindrical body 1a on several spiral groove-shaped mounting surfaces 3 formed on the outer peripheral surface 1b of the cylindrical body 1a. 1 pitch of overlapping
The concave portions 3a with screw holes are arranged along the spiral path of the stripe. The recess 3a is provided with the throwaway tip 10
As shown in FIG. 4, it is formed so as to partially project from the outer peripheral surface 1b and to be fitted at a slight inclination with respect to the central axis B along the mounting surface 3. Then, the throw-away tip 10 is fitted into each recess 3a, and is screwed to the cylindrical body 1a by the screw 9 through the screw through hole 15. In such a fixed state to the cylindrical body 1a, the front end surface 12a of the finishing blade 12 coincides with the radial direction of the cylindrical body 1a at an intermediate position in the central axis B direction, and the center thereof with respect to this radial direction. The axis A is orthogonal. Further, the rough cutting blade 11 is positioned in front of the finishing blade 12 in the rotation direction C, and the outer edge 11 c of the rough cutting blade 11 is the outer edge 1 of the finishing blade 12.
It occupies a position closer to the central axis B than 2c, and both project outward from the outer peripheral surface 1b.

As a result, during contouring by the end mill 1 equipped with the two-step type throwaway tip 10, FIG.
As shown in FIG. 5, the roughening blade 11 is in front of the rotation direction C due to the rotation of the cylindrical body 1a, so that the roughening process is performed by hitting the work 27 first, and then the large radius position of the second step. Finishing is performed by hitting the roughened portion of the finishing blade 12. At that time, chips are smoothly discharged through the space formed by the flank 11b of the rough cutting blade 11, the front end surface 12a of the finishing blade 12 and the boss portion 13 along with the spiral groove-shaped mounting surface 3 without being clogged with chips. To be done.

The shape of the throwaway tip 10 viewed from the axial direction is not limited to the above-mentioned quadrangle, but may be various shapes such as a triangle and a circle. The boss can be eliminated depending on the shape of the flank of the rough cutting blade.

[0011]

As described above, according to the present invention, the throwaway tips arranged in the end mill are integrally formed with the two-step blades for roughing and finishing, so that roughing can be performed without changing the tool. The finishing process is performed at the same time. Therefore, it is extremely advantageous in terms of tool cost and management. At this time, according to the second aspect, the boss portion is interposed between the rough cutting blade and the finishing blade, so that the chips are reliably discharged. Further, according to the third aspect, since the end face of the finishing blade is aligned in the radial direction with the axis as the center, the rotational force can be effectively used for finishing.

[Brief description of drawings]

FIG. 1 is a side view of an end mill throwaway tip portion according to an embodiment of the present invention.

FIG. 2 is a front view of the throwaway tip.

FIG. 3 is a side view of an end mill in which the throw-away tips are arranged.

FIG. 4 is a cross-sectional view of a cut portion showing a processing state by the end mill.

[Fig. 5] Fig. 5 shows a conventional roughing end mill.
Is a side view for roughing, and FIG. B is a side view for finishing.

FIG. 6 is a perspective view showing a contour processing state of a work by an end mill.

[Explanation of symbols]

 1 End Mill 1a Cylindrical Body 3 Mounting Surface 10 Throwaway Tip 11 Roughing Blade 11c, 12c Outer Edge 12 Finishing Blade 13 Boss Part

Claims (3)

[Claims] 1. An end mill in which throw-away tips are arranged on a spiral groove-shaped mounting surface formed on an outer peripheral surface of a cylindrical body which is held by a milling machine and driven to rotate, wherein the throw-away tips are attached to the cylindrical body. The rough cutting blade located in the front in the rotation direction and the finishing blade located behind this blade are integrally formed, and the outer edge of the rough cutting blade is more cylindrical than the outer edge of the finishing blade. An end mill characterized in that it is formed so as to be close to the center of each of the outer peripheral surfaces and project from the outer peripheral surface. 2. A throwaway tip has a roughing blade,
The finishing blade having an outer shape larger than the outer shape, and an outer shape smaller than these blades, and a boss portion interposed between these blades are coaxially and integrally formed. End mill. 3. The end mill according to claim 1 or 2, wherein a flat front end face of the finishing blade which faces the rotation direction partially coincides with the radial direction of the cylindrical body.