JPH0771768B2 - End mill - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an end mill in which a cutting edge is formed on the outer periphery of a cylindrical end mill body that rotates around an axis from the tip to the base end. It is a thing.

[Prior Art] Generally, when performing groove processing or step processing on a material to be cut, various end mills in which a cutting edge is formed along the axial direction of the outer circumference of a tool body are used.

9 and 10 show a throwaway type end mill in which a plurality of throwaway chips are detachably mounted as the above-mentioned cutting blades among the conventional endmills of this type, and reference numeral 1 in the drawings is an endmill. The main body is shown.

The end mill main body 1 has a substantially cylindrical outer shape with a shank portion 2 formed at a base end portion, and a front end surface 3 thereof is formed by a plane orthogonal to an axis.

On the outer periphery of the end mill body 1, a total of six chip pockets 4 are formed at equal intervals in the circumferential direction and at positions where a spiral shape is drawn as a whole from the distal end portion toward the proximal end side, and each chip pocket is further formed. A groove-shaped chip mounting seat 5 is formed on the wall surface of the groove 4 which faces the rotational direction.

A throwaway chip 6 made of cemented carbide or the like is detachably attached to each chip mounting seat 5 by a clamp screw 7. These throwaway chips 6 ...
Are mounted such that the cutting blades 8 ... Protruding from the outer periphery of the end mill body 1 are axially continuous with each other in their respective rotation loci. Further, the throw-away tip 6 located at the most distal end of the end mill book 1 is mounted with a cutting edge 9 adjacent to the cutting edge 8 protruding toward the tip side of the end mill body 1.

In the above conventional end mill having the above configuration,
As the end mill body 1 rotates, the cutting blades 8 of the throwaway tip 6 ... side the side surface W _{2 of the work} material W, and the tip 9 of the throwaway tip 6 cuts the side surface W ₂ of the work material W _1. Each is cut to form a groove or step in the work W.

[Problems to be Solved by the Invention] However, in the above conventional end mill,
As shown in the figure, the end mill body 1 and the bottom surface W _{1 of the work} material W
Since the gaps L ₁ and L ₂ between the side surface W ₂ and the side surface W ₂ are small, so-called chips are liable to be caught, and as a result, the cutting edge 9 which is the bottom blade is particularly likely to be damaged and the end mill body 4 is easily damaged. There was a drawback. Moreover, the chips cut by the throwaway chip 6 on the base end side of the end mill body 1 are the work materials W.
If it falls on the bottom surface W _{1 of the} end mill, the chips will be rubbed between the tip surface 3 and the bottom surface W _{1 of the work} material W when the end mill is laterally fed, and as a result, the bottom surface W ₁ There is also a problem that the surface roughness of the is decreased.

On the contrary, if the amount of overhang of the cutting blade 8 of the throwaway tip 6 (the amount of protrusion from the outer circumference of the end mill body 1) is increased in order to increase the gaps L ₁ and L ₂ , the cutting edge strength decreases. There has been a problem that it cannot withstand the medium-duty cutting that is normally used.

[Object of the Invention] The present invention has been made in view of the above circumstances, and can prevent chips from being caught without lowering the cutting edge strength. It is an object of the present invention to provide an end mill that does not cause a decrease in thickness.

[Means for Solving Problems] The end mill of the present invention has
It is formed by at least one inclined surface that inclines with respect to a plane orthogonal to the axis of the end mill body, and the tip end portion of this inclined surface in the axial direction is positioned so as to be aligned with the tip of the cutting blade of the end mill. is there.

[Operation] In the end mill having the above configuration, a large gap is formed between the tip surface of the end mill body and the bottom surface of the work material.
As a result, so-called chips are not bitten, and the generated chips are not rubbed between the tip surface of the end mill body and the bottom surface of the work material.

[Embodiment] FIGS. 1 and 2 show an example of the end mill of the present invention, in which reference numeral 10 is an end mill main body having a substantially cylindrical appearance.

On the outer periphery of the end mill body 10, a pair of chip pockets 11, 11 extending in the axial direction are formed at symmetrical positions with respect to the axial line, and the wall surfaces facing the rotational direction of the chip pockets 11 are respectively formed. 3 chip mounting seats 12
Are formed so as to alternate in the axial direction. Further, diamond-shaped throwaway chips 13 ... Are provided on the respective chip mounting seats 12 ...
Are continuously attached to each other in the axial direction in the rotational loci of each other and are detachably attached. In addition, the cutting edge of the throwaway tip 13 located at the tip of the end mill body 10
The auxiliary cutting edge adjacent to 14 is the bottom blade 15.

The tip surface 16 of the end mill body 10 has a tip end portion where the throwaway tip 13 is located as the tip end portion in the axial direction, and is inclined at a predetermined angle with respect to a plane orthogonal to the axis line. It is formed by an inclined surface. That is, in the present embodiment, the tip surface 16 is formed by one inclined surface inclined with respect to the plane orthogonal to the axis of the end mill body 10, and this inclined surface has the most distal end in the axial direction of the end mill body. It is aligned with the position of the tip of the cutting blade 14 of the throw-away tip 13 mounted at the tip of the end mill body 10 in the circumferential direction of 10.

In the end mill of this example having the above structure, the side surface W _{2 of the work} W is formed by the cutting blades 14 of the throwaway tip 13.
And the bottom edge 15 of the throw-away tip 13 at the tip of the end mill body 10 is used to cut the bottom surface W ₁ of the work material W.

In such an end mill, since the tip surface 16 of the end mill body 10 is formed by an inclined surface, as shown in FIG. 1, the gap between the tip surface 16 and the bottom surface W _{1 of the work} material W is A large gap 17 is formed at. Therefore, especially the throwaway tip 13 located on the tip side of the end mill body 10 ...
In the above, it is possible to reliably prevent the so-called chip biting. Moreover, even if the chips cut by the throwaway tip 13 located on the base end side of the end mill body 10 fall onto the tip surface 16 side of the end mill body 10, the chips are not in contact with the bottom surface W _{1 of the work} material W. It will not be rubbed with.

As a result, the chip discharging performance is excellent, and further, the cutting blade 14 of the throwaway chip 13 located on the tip side of the end mill body 10 and the end mill body 10 itself are damaged by the chips, or are cut. Bottom of material W
There is no fear that the surface roughness of W ₁ will be reduced.

[Other Embodiments] FIGS. 3 to 5 show a second embodiment of the present invention.
In this end mill, two throwaway chips 21a, 21b are mounted on the outer periphery of the end portion of the end mill body 20 at symmetrical positions with respect to the axis. In addition, on the outer circumference of the end mill body 20, the end mill body 20 from the pair of throwaway chips 21a and 21b, respectively.
Two two throwaway chips 22 ... Are mounted at equal intervals in the circumferential direction toward the base end side.

The end surface 23 of the end mill main body 20 has an inclined surface 24 inclined from one of the throw away chips 21a to the base end side of the end mill main body 20 with the line connecting the throw away chips 21a and 21b as a boundary, It is formed by the other throw-away chip 21b and an inclined surface 25 inclined toward the base end side of the end mill main body 20.

6 to 8 show a third embodiment of the present invention. In this end mill, six throw-away chips 31 are provided on the outer periphery of the end mill main body 30 from its tip end toward its base end. ... are attached in a spiral shape.

The tip end surface 32 of the end mill body 30 is formed by a spiral inclined surface that gradually inclines toward the base end side of the end mill body 30 along the throwaway chips 31 ... which are sequentially arranged from the tip end portion toward the base end side. Has been formed.

Even in the end mills described in the second and third examples, the tip surfaces 23, 32 of the respective end mill bodies 20, 30 during cutting.
Since the large gaps 26 and 33 are formed between and the bottom surface W _{2 of the work} material W, the same effect as the end mill shown in the first embodiment can be obtained.

In the above examples, the end mill body
Throw-away tip 1 as a cutting edge on the periphery of 10, 20, 30
Although we have described the throwaway type end mill equipped with 3, 21a, 21b, 22, and 31, it is not limited to this, it is a so-called solid type end mill in which the cutting edge is integrally formed on the outer circumference of the end mill body. Even if it is, the same effect can be obtained.

[Effects of the Invention] As described above, in the end mill of the present invention, the tip end surface of the end mill body is formed by at least one inclined surface inclined with respect to the plane orthogonal to the axis of the end mill body. Since the most distal end in the axial direction is positioned in line with the tip of the cutting edge of the end mill,
Since a large gap is not formed between the tip surface of the end mill body and the bottom surface of the work material, so-called chips are not caught, the cutting edge strength is not reduced, and the bottom blade is damaged or cut. It is possible to obtain excellent effects such as prevention of reduction in surface roughness of the material.

[Brief description of drawings]

FIGS. 1 and 2 show a first embodiment of the end mill of the present invention. FIG. 1 is a front view, FIG. 2 is a side view, and FIGS. 3 to 5 are second embodiments of the present invention. FIG. 3 is a front view, FIG. 4 is a side view, FIG. 5 is a perspective view showing a schematic shape of the end face of the end mill body, and FIGS. 6 to 8 are third examples of the present invention. FIG. 6 shows an embodiment, and FIG.
FIG. 7 is a side view, FIG. 8 is a perspective view showing a schematic shape of the tip end surface of the end mill body, FIGS. 9 and 10 show a conventional end mill, and FIG. 9 is a front view and FIG. Is a side view. 10,20,30 …… End mill body, 13,21a, 21b, 22,31 …… Throwaway tip, 14 …… Cut blade, 15 …… Bottom blade, 16,23,
32 …… Tip surface, 17, 26, 33 …… Gap, 24, 25 …… Inclined surface,
W ... Work material, W ₁ , W ₂ ... Bottom or side surface of groove or step formed in work material W.

Claims (1)

[Claims] 1. An end mill comprising a cylindrical end mill body having a cutting edge formed on the outer periphery of the end mill body from the tip to the base end of the end mill body. The end face of the end mill body is orthogonal to the axis of the end mill body. The end mill is formed by at least one inclined surface that is inclined with respect to the plane, and the tip end of the inclined surface in the axial direction is aligned with the tip of the cutting blade.