JP3179770B2 - Tip insert for ball end mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tip blade tip for a ball end mill, and more particularly to an improved cutting edge and mounting structure thereof.

[0002]

2. Description of the Related Art Conventionally, as a tip blade tip for this type of ball end mill, those disclosed in Japanese Utility Model Laid-Open Nos. 54-21895, 54-26195, 63-140315, etc. It has been known.

In the former two cases, a so-called spiral blade is formed by forming a convex curved surface on a rake surface at a rotation center portion.

On the other hand, the last is that the outer shape of the chip is composed of a pair of long arcuate side surfaces and a short plane side surface, and the short plane side surface has a thickness from the center to the upper and lower surfaces. Is formed so that a convex curved surface is formed so as to decrease, and the outer shape of the chip is formed of three arcuate side surfaces, and the convex curved surface is similarly formed at a corner portion thereof.

[0005]

However, the tip blade tip disclosed in the above-mentioned publication has a weak mounting rigidity because the tip seat is two-sided when mounted on the tool body, and has a problem such as deep groove cutting. Cutting is unplanned. On the other hand, in the rough machining of this kind of a boring end mill, cutting by traversing transverse feed is required, and the development of a tip blade tip adapted to this is demanded.

In view of the above, according to the present invention, the cutting edge configuration and mounting rigidity of the tip blade tip are improved,
The above-described rush transverse feed cutting is made possible.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has an inclined arc-shaped side face between a long side face and a short side face which are substantially parallel to each other. This is an improvement based on the premise of a tip end for a ball end mill having a four-sided plate shape.

That is, the long side surface and the short side surface are substantially at right angles to the upper surface and the lower surface, and the arcuate side surfaces are inverted with respect to the upper surface and the lower surface so that they can be used upside down. It is a symmetrical shape.

On the upper and lower surfaces of the corner portion on the long side surface, a belt-shaped surface formed of a convex curved surface or a plurality of inclined surfaces is formed toward the center of the thickness of the long side surface. Has an inclined surface intersecting with the belt-like surface formed adjacent to the arc-shaped side surface.

[0010]

The tip blade tip for a ball end mill according to the present invention is of a two-corner type that can be used upside down, and has three sides for restraining the tip seat. It is what is being done. In addition, the cutting performance is improved in the corner portion because the edge configuration is obtained by forming the belt-shaped surface.

【Example】

An embodiment of a tip blade tip for a ball end mill according to the present invention will be described below with reference to the drawings.

1 and 2, reference numeral 1 denotes a tip blade tip for a ball end mill in which a center mounting hole 2 is formed. The tip blade tip 1 has a four-sided plate shape.

That is, the tip blade tip 1 has arcuate side surfaces 5 and 5 with an inclination formed between the long side surface 3 and the short side surface 4 which are substantially parallel to each other. The upper surface 6 and the lower surface 7 are symmetrical so that they can be used.

The long side surface 3 and the arcuate side surface 5,
5 has a symmetric band-shaped surface 8 formed on the upper surface 6 and the lower surface 7 thereof, and an inclined surface 9 intersecting with the band-shaped surface 8 on the opposite side of the band-shaped surface 8. It is formed adjacent to the arc-shaped surface 5. In this case, the belt-shaped surface 8 is formed of a convex curved surface as shown or a plurality of inclined surfaces (not shown) toward the thickness center of the long side surface 3. In this case, a so-called spiral blade having a convex curve is formed by the intersection with the flank of the tip formed on the arc-shaped side surfaces 5 and 5.

On the other hand, FIGS. 3 to 5 show a throw-away type ball end mill in which the tip blade tip 1 is incorporated in a tip seat 12 formed in a rod-shaped tool body 11. It is.

When the tip blade tip 1 is placed in the tip seat 12 of the tool body 11, the long side face 3
One of the corner portions constituted by the arc-shaped side surfaces 5 and 5 is located near the center of rotation of the tool main body 11, and the rake face constituted by the upper surface 6 or the lower surface 7 is brought into a center-high state and participates in cutting.

The tip seat 12 has a substantially U-shape, and the long side surface 3 is in the direction of the axis of the tool body 11 and is in contact with the short side surface 4 on both side walls. The arcuate side surface 5 not involved in cutting is in contact with the rear wall.

In the illustrated throw-away ball end mill, the tip blade tip 1, the arc-shaped blade tip 13 and the straight blade tip 14 are screwed in two flute grooves 16 extending in the axial direction. I have. In this case, as the arc-shaped blade tip 13, a positive tip having three arc side faces is applied, and as the straight blade tip 14, a positive tip having four inclined side faces is applied.

Further, as shown in FIG. 6, the arrangement of the straight blade tip 14 is such that the outer diameter of the cutting edge is smaller than the outer diameter of the cutting edge of the arcuate blade tip 13. For example, if the cutting edge outer diameter of the arc-shaped blade tip 13 is φ40 mm, the cutting edge outer diameter of the straight blade tip 14 is φ
39 mm. In other words, as shown in FIG. 6, it is located on the smaller diameter side at δ = 0.5 mm. this is,
It is designed to be effective when piercing cutting is performed in the axial direction with lateral feed.

[0020]

As described above, the tip blade 1 of the ball end mill according to the present invention employs a cutting edge configuration by forming the belt-like surface 8 and a mounting configuration by the three-surface constraint in the tip seat 12. In addition, the mounting rigidity is improved, and the cutting performance can be expected to be improved in rough machining of a ball end mill.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a tip blade tip for a ball end mill of the present invention,

FIG. 2 is a side view,

FIG. 3 is a front view of a main part of a throw-away type ball end mill in which a tip blade for a ball end mill of the present invention is attached to a tool body.

FIG. 4 is a bottom view of FIG. 3;

FIG. 5 is a partial side view of FIG. 3;

FIG. 6 is an explanatory diagram showing a relationship in a rotation locus of an arcuate blade tip and a straight blade tip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tip blade tip 3 Long side surface 4 Short side surface 5 Arc side surface 6 Top surface 7 Lower surface 8 Strip surface 9 Inclined surface 11 Tool body 12 Tip seat 13 Arc blade tip 14 Straight blade tip

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23C 5/10 B23C 5/20

Claims (1)

(57) [Claims] 1. An end for a ball end mill having a four-sided plate shape by forming arcuate side surfaces 5 and 5 with inclination between a long side surface 3 and a short side surface 4 in a substantially parallel relationship. In the blade tip, the long side surface 3 and the short side surface 4 are substantially perpendicular to the upper surface 6 and the lower surface 7, and the arcuate side surfaces 5 and 5 are turned upside down so that they can be used. And the lower surface 7 have a symmetrical shape with the inclination being inverted. Further, the upper surface 6 and the lower surface 7 constituting the rake face at the corner portion on the long side 3 side have a thickness center of the long side 3. A belt-like surface 8 composed of a convex curved surface or a plurality of inclined surfaces is formed, and a slope 9 intersecting with the belt-like surface 8 is formed adjacent to the arc-shaped side surface 5 on the opposite side of the belt-like surface 8. Tip end tip for ball end mill Up.