Method for selecting a milling cutter for machining

Abstract

A method for selecting a milling cutter, which method makes it possible to select a milling cutter on the basis of a part to be machined such that the cutting force is constant while the part is being machined.

Claims

1. Method for selecting a milling cutter on the basis of a part to be machined, the milling cutter comprising: a cylinder having a circular cross section of radius R and having an axis of rotation; a plurality of cutting edges in a number M, arranged along parallel helical lines extending along an outer surface of the cylinder, the edges defining, together with the direction of the axis of the cylinder, a helix angle , the edges enclosing constant angles in a plane that is perpendicular to the axis such that =360/M; the method comprising: providing a part having a side; determining a height h of the side; and electing a milling cutter having values of , and R such that the following equation is satisfied: $\frac{\mathrm{tg}\left(\right)}{R}=\frac{\mathrm{integer}}{h}.$

2. The method of claim 1, wherein the number M of cutting edges of the milling cutter is between 1 and 10.

3. The method of claim 2, wherein the number M of cutting edges of the milling cutter is between 2 and 6.

4. The method of claim 1, wherein the helix angle is between 10 and 80.

5. The method of claim 4, wherein the helix angle is between 20 and 70.

6. Milling arrangement comprising a milling cutter and a part, said milling cutter permitting lateral milling of said part, said milling cutter comprising: a cylinder having a circular cross section of radius R and having an axis of rotation; a plurality of cutting edges in a number M, arranged along parallel helical lines extending along an outer surface of the cylinder, the edges defining, together with the direction of the axis of the cylinder, a helix angle , the edges enclosing constant angles in a plane that is perpendicular to the axis such that =360/M; said part having a side facing said milling cutter that has a height h measured in parallel with the axis of the cylinder of the milling cutter, wherein the values of , and R satisfy the following equation: $\frac{\mathrm{tg}\left(\right)}{R}=\frac{\mathrm{integer}}{h}.$

7. The milling arrangement of claim 6, wherein the number M of cutting edges of the milling cutter is between 1 and 10.

8. The milling arrangement of claim 7, wherein the number M of cutting edges of the milling cutter is between 2 and 6.

9. The milling arrangement of claim 6, wherein the helix angle is between 10 and 80.

10. The milling arrangement of claim 9, wherein the helix angle is between 20 and 70.

11. The milling arrangement of claim 6, wherein the side of the part facing the milling cutter is substantially planar.

12. The milling arrangement of claim 6, wherein the side of the part facing the milling cutter is parallel to the axis.

Description

DESCRIPTION OF THE DRAWINGS

(1) The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

(2) FIG. 1 is a perspective view of a portion of a milling cutter of an arrangement according to an aspect of the disclosure;

(3) FIG. 2 schematically shows a milling arrangement according to an aspect of the disclosure; and

(4) FIG. 3 schematically shows a surface of the milling cutter included in the milling arrangement, flattened on a plane, and the part to be milled.

DETAILED DESCRIPTION

(5) Embodiments of the present disclosure are described on the basis of specific examples and with reference to the drawings, but such embodiments should not be limited thereby. The drawings described are only schematic and are not limiting.

(6) In the context of the present document, the terms first and second are used only to differentiate the different elements and do not imply an order between these elements.

(7) In the drawings, identical or similar elements may have the same reference signs.

(8) FIG. 1 shows a milling cutter 1 according to an aspect of the disclosure, which comprises a straight circular cylinder 2 having an axis of rotation 5 and an outer surface, and M cutting edges 3 arranged along parallel helical lines extending along the outer surface of the cylinder 2.

(9) In FIG. 1, M is equal to 2. M is an integer. M in some embodiments is between 1 and 10. M in other embodiments is between 2 and 6. In the present document, the expression A is between B and C means that A may assume values between B and C, including B and C.

(10) A helix angle, which is the angle between the tangent at an edge 3 and the direction of the axis 5 of the cylinder, is denoted by . The helix angle, , in some embodiments is between 10 and 80. The helix angle, , in other embodiments is between 20 and 70.

(11) FIG. 2 schematically shows a milling arrangement according to an aspect of the disclosure, comprising the milling cutter 1 and the part 4 intended to be machined by the milling cutter 1. The milling cutter 1 is shown having the straight circular cylinder 2 and the M cutting edges 3. The edges 3 enclose a constant angle , being measured on the axis 5, in a plane perpendicular to the axis. is related to the number M of edges 3 of the milling cutter by the equation:

(12) $=\frac{2}{M}$

(13) A radius of a cross section of the cylinder 1 perpendicular to the axis 5 is denoted by R.

(14) The part 4 intended to be machined by the milling cutter 1, by placing the milling cutter 1 into contact with the part 4 on a side 6 of the part 4. This side 6 of the part 4 in contact with the milling cutter 1 in some embodiments is planar and parallel to the axis 5. This side 6 of the part 4 has a height h measured in parallel with the axis 5.

(15) The height of the milling cutter 1, measured in parallel with the axis 5, is greater than h.

(16) The milling cutter 1 can be mounted on a spindle (not shown) using a sleeve or a mandrel (shown). The spindle rotates the milling cutter 1 about the axis 5.

(17) FIG. 3 schematically shows a surface of the milling cutter 1 flattened on a plane such that the outer surface of the cylinder 2 becomes a rectangle 7. The perimeter of a cross section of the cylinder 2, equal to 2R, corresponds to the length of a side of the rectangle 7. The length Pa of an arc of a circle swept by an edge 3 along the height h is such that

(18) $\tan \left(\right)=\frac{\mathrm{Pa}}{h}$

(19) The angle in the centre made by this arc of a circle swept by an edge 3 along the height h is equal to

(20) $=\frac{\mathrm{Pa}}{R}$

(21) The number N of edges 3 engaging with the part 4 equals

(22) $N=\frac{}{}+1$

(23) The condition for a constant number of edges to engage with the part 4 during the rotation about the axis 5 is therefore

(24) $\frac{}{}=\mathrm{integer}=>\frac{h\mathrm{tg}\left(\right)}{R}=\mathrm{integer}$

(25) A method is provided consisting of selecting the characteristics , and R of the milling cutter 1 on the basis of the height h of the part 4 in order for this equation to be satisfied, such that a constant number of edges engages with the part 4 during the rotation of the milling cutter 1 about the axis 5.

(26) In other words, several embodiments relate to a milling arrangement comprising a milling cutter 1 and a part 4, which arrangement is intended for laterally milling a part 4 having a predetermined height, the characteristics of the milling cutter 1 being suitable for allowing the force of the milling cutter 1 on the part 4 to be constant over time.

(27) The disclosed subject matter has been described in relation to specific embodiments which are purely illustrative and should not be considered to be limiting. In general terms, the claimed subject matter is not limited to the examples shown and/or described above. The use of the verbs comprise, include, consist of, or any other variant, as well as the conjugations thereof, cannot in any way exclude the presence of elements other than those mentioned. The use of the indefinite article a or an or of the definite article the to introduce an element does not exclude the presence of a plurality of said elements. The reference signs in the claims do not limit the scope thereof.

(28) While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the claimed subject matter.