JPS61284312A - Throw away tip for ball end mill - Google Patents

Abstract

PURPOSE:To decrease a time for arrangements and tools on hand, by continuously forming an upper surface cutting edge, having an arc-shaped or linear ridge line, on a peripheral side cutting edge so that the tool may perform cutting with no necessity for taking trouble on edge length of a mill and a machine tool even if a cut surface forms a shape of deep groove and curved surface or center spread. CONSTITUTION:A plate-shaped tip 1, having a mounting hole 11, provides a rake face 10 in one side and a fixed surface 101 in the other, continuously forming a protrusive cutting edge 12 and a linear cutting edge 13, as viewed from the side, in upper and bottom side surfaces. The tip 1, forming its cutting edge ridge line 14 with a bottom surface cutting edge 15 in a linear shape, as viewed from the plane, while a peripheral side cutting edge 16 and an upper surface cutting edge 17 in an arc shape and smoothly connecting these three contact points, forms a clearance angle 18 of ph fixed angle. In this way, the tip, only requiring a small effective edge length and efficiently performing also undercutting, decreases a cutting load to eliminate insufficiency of rigidity in a shank, and a machine tool is prevented from a defect by reducing the required horsepower and preventing chattering.

Description

[Detailed Description of the Invention] [Industrial Applications] The present invention relates to an indexable tip used for Houendomi A/, which enables efficient deep cutting, especially in engraving cutting of molds, etc. This relates to a throw-away tip that has been improved so that it can be used.

[Prior art]

Conventionally, for metal cutting, especially for cutting of molds and the like where the work surface is uneven due to cutting materials, the bottom surface of the cutting edge is shaped like a convex cutting edge near the starting edge of the cutting edge, and the tool If! A ball end mill is used in which the rotation projection has a hemispherical shape at the end at the time of I@, and the shaft has a cylindrical shape continuously.

[Problem that the invention seeks to solve]

However, the cutting area of the ball end mill described above is for the purpose of carving a mold made of difficult-to-cut materials.

These molds are often machined with deep grooves, curved surfaces, or are widened in the middle and curved or sloped surfaces. Conventionally, these cutting processes were performed using a ball end mill with a long effective cutting edge, or the pole end mill was attached to the machine tool spindle at an angle that matched the workpiece surface, and then the cutting process was performed. do. It takes time and effort to make special tools such as these or adjust the machine tools, and there are problems such as the inability to perform efficient cutting no matter what.

[Purpose of the invention]

The present invention was developed in view of the above-mentioned problems, and even if the shape of the workpiece surface is a deep groove, a curved surface or a medium spread, and even a curved or sloped surface, the length of the blade or the machine tool etc. The object of the present invention is to provide an economical indexable insert for a ball end mill that can be easily cut without adding any additional material and that reduces setup time and hand tools.

[Means for solving problems]

The present invention solves the above-mentioned problems by using the configuration described below.

That is, a linear cutting edge is provided on one or both side surfaces to form a convex cutting edge, and the ridges of the convex cutting edge and the linear cutting edge form an arc or a bottom cutting edge consisting of a straight line and an arc. , which is continuous with an arc-shaped circumferential cutting edge, and an upper cutting edge having an arc-shaped or linear ridge line is formed continuously with the circumferential cutting edge, and the cutting edge has a flank having a predetermined relief angle. This is a throw-away tip for ball end mills that is equipped with.

[Action of the invention]

First, we will discuss the differences in the functions of the conventional ball end mill and the ball mill of the present invention.

Figure 1 (al) shows the conventional ball endome A/
(b) is an explanatory diagram of cutting a workpiece T having a slope C using the bow V end mill A/B of the present invention. , is an explanatory diagram when .

As can be understood from the figure, in the case of the conventional ball end mill A/A, when attempting to cut a slope C by giving a depth of cut d■ and a feed F, it is necessary to make the effective length S of the end mill A long. be. This increases the cutting load applied to the cutting edge, resulting in % +7, which causes chipping of the cutting edge and at the same time greatly reduces the accuracy of the cut surface.

In addition, if the above-mentioned problem is to be improved by reducing the effective length S for the same amount of cutting, the mounting position of the end mill A/A on the slope C of the workpiece T will be changed so that the above-mentioned cutting is possible. In order to do this, it is necessary to tilt the tool by a predetermined angle toward the tool attachment of the machine tool, but this requires a lot of setup time and is not a preferable method.

However, according to the ball end mill EK- of the present invention shown in FIG. Even when cutting under these conditions, the effective flute length s1 can be small, and undercutting can be performed efficiently. This eliminates the problem or reduces the required horsepower of the machine tool, which prevents tearing and at the same time prevents chipping of the cutting edge and greatly extends tool life.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 6 attached hereto.

The plate-shaped plate has a mounting hole 11 in its center for inserting a tightening bolt used to fix the chip to the chip seat of the shank, and has a rake face 10 on one side and a hole 11 on the other side. The fixed surface 10+ is fixed, and convex cutting edges 12 are formed on the upper and lower sides, and cutting edges that become straight cutting edges 15 when viewed from the side (Fig. 5) are continuously formed. At the same time, the ridgeline 111 of the cutting edge is such that the bottom cutting edge 15 is linear in plan view (FIG. 2), the circumferential cutting edge 16 and the top cutting edge 17 are arcuate, and these five contact points are smoothly joined. At the same time, the cutting edge is formed with a relief angle 18 having a predetermined angle.

A flat part 19 is provided adjacent to the convex cutting edge 12 and serves as a contact surface against the chip seat wall surface so that the chip can be stably held 17 on the chip fixing seat of the shank, and a flat part 19 is provided that serves as a contact surface for the chip seat wall surface. In order to prevent chipping, two fins y20 are formed at the end of the convex cutting edge 12.

In the above, the upper cutting edge 17 is arcuate, but even if it is formed into a straight cutting edge 171 having a predetermined inclination angle as shown by the imaginary line in FIG. 2, the undercutting effect will be impaired. It's not a thing. Even in the above-mentioned cutting edge shape, if the rotational projection of the end portion is formed in an arc shape when the tool is rotated, the machining area during machining will increase.

Note that even if the bottom cutting edge 15 and the circumferential cutting edge 16 have a straight line and an arc shape, or an arc shape and an arc shape, as described above, when the tool is rotated #C, the cutting edge ridgeline will not form a circular arc. All you have to do is draw it. Furthermore, in this embodiment, a pair of symmetrical cutting edges are provided on the upper and lower sides of the tip, and if one cutting edge is damaged, the chi knob is rotated 180 degrees and the other cutting edge is removed.

However, if one side is formed with the cutting edge of the above configuration and the other side is formed in a shape that can be closely and easily fixed to the chip fixing seat wall surface of the shank, the chip to the shank can be improved.・The reso adhesion force is strengthened, making it suitable for heavy cutting, and it also prevents tip chipping and rattling, prolonging tool life and providing a highly accurate machined surface.

When using the tip knob 1 having the above configuration, the tip is attached to the notch surface of the spherical tip 21 of the shank 2 by using the screw hole 22 corresponding to the hole It and the tip as shown in FIGS. 4 to 6. A shank consisting of a chi-knob fixing seat 211 that has a protrusion 25 that is brought into close contact with the flat part 19 and that can be fitted in a normal state with 1000 degrees of rotation, and a chip discharge groove 25 provided on the rotational front side of the fixing seat. The tip knob is fitted into the tip fixing seat 2u of No. 2, and the tip is firmly fixed with a portola, and then the tool No. 2 is attached to a machine tool (not shown).

〔Effect of the invention〕

Previous above l1. The conditions for comparing and testing the performance of the conventional Bo-V Entomy A/A and the aforementioned Po-V Endomi PV73 according to the present invention were as follows: Machine used: Vertical milling machine (50 mm), Cutting material: 5550.Cutting: die-sinking cutting, rotation speed: 1200r
pm, circumferential speed: 9 Gwr, /win, feed: pot 5
0~560 m/= (α 375~ α 5
m/rev), cutting method: dry cutting (air plow), others: protrusion length from the end face of the hoarder to the cutting edge is near 0 m, etc.

The above test results show that with the conventional bow μ end mill/I/A, the volume of the effective cutting edge involved in cutting is large, which increases the cutting resistance, causing beading and deteriorating the surface accuracy of the workpiece. It was impossible to pull up the wall surface of the workpiece.

In contrast to the conventional ball end mill mentioned above, the ball end mill/L/B according to the present invention has less volume of the effective cutting edge involved in cutting and stable cutting resistance15. With this tool, smooth cutting was achieved without any chattering or wobbling on the tip. Moreover, the lifting cutting of the wall surface of the mold was also performed well.

[Brief explanation of the drawing]

Figures 1a-b are explanatory diagrams of the operation, Figures 2 and 5 show the chip of the present invention, Figure 2 is a plan view, Figure 5 is a top view, and Figure 4 is a main view. A front view of the industrial μ equipped with the chip of the invention; FIG. 5 is a cross-sectional side view of the main part of FIG. 4;
FIG. 6 is a bottom view of FIG. 5, etc. l...Tip, 2...Shank, 5
...Tighten with bolt, 12... Convex cutting edge, 15... Straight cutting edge, lu...
...cutting edge ridgeline, 15...-bottom cutting edge,
16... Circumferential cutting edge, 17... Top cutting edge. Fig. 1) Δ Fig. 4 Fig. 5 Fig. 6

Claims (1)

[Claims] (1) A linear cutting edge is provided on one or both sides to form a convex cutting edge, and the ridge line of the convex cutting edge and the linear cutting edge forms an arc or a bottom cutting edge consisting of a straight line and an arc. This is continuous with an arc-shaped circumferential cutting edge, and an upper cutting edge having an arc-shaped or linear ridge line is formed continuously from the circumferential cutting edge, and a relief having a predetermined relief angle is formed on the cutting edge. A throw-away tip for pole end mills that features a surface.