Method for drilling a stack of materials, drill bit and drilling device

Patent metadata

Field	Value
Publication number	US-2016136736-A1
Application number	US-201514716868-A
Country	US
Kind code	A1
Filing date	May 19, 2015
Priority date	May 7, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A method for drilling through an assembly forming a stack of at least two different materials uses a drill bit having at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that the end of the drill bit has a projecting conical shape. The first cutting edge is configured to drill a first material. The second cutting edge is made differently from the first cutting edge, to drill a second material. A first rotational drive axis of the drill bit is laterally offset during the drilling by an offset distance D relative to the axis of the drill bit in a direction opposite the first cutting edge when the drill bit is drilling through the first material, and alternately, in a direction opposite the second cutting edge when the drill bit is drilling through the second material.

First claim

1 - 24 . (canceled)

25 . Drilling device comprising a driver to drive a chuck in rotation around a first axis, a drill bit having an axis, the drill bit comprising at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that an end of the drill bit has a projecting conical shape;
the first cutting edge is configured to drill a first material; the second cutting edge is made differently from the first cutting edge and configured to drill a second material; the chuck maintains the axis of the drill bit on a second axis of the chuck parallel to the first axis at an offset distance D from the first axis, the drill bit being mounted to the chuck so as to be driven in rotation at a rotation speed of the chuck; and the chuck and the drill bit comprise at least two distinct positions of the first axis relative to the axis of the drill bit for laterally offsetting the first axis relative to the axis of the drill bit in a direction opposite the first cutting edge in a first position and for laterally offsetting the first axis relative to the axis of the drill bit in a direction opposite the second cutting edge in a second position.

26 . Device according to claim 25 , wherein the first cutting edge and the second cutting edge are inclined in the axial plane of the drill bit so that they each form, with the axis of the drill bit, an angle between about 60 degrees and 45 degrees.

27 . Device according to claim 25 , wherein each of the first and second positions of the first axis relative to the axis of the drill bit corresponds to an offset from the first axis between 0.05 mm and 0.2 mm.

28 . Device according to claim 25 , wherein the first cutting edge is configured to drill hard metals.

29 . Device according to claim 28 , wherein the first cutting edge is formed of a tungsten carbide configured to drill titanium-based alloys.

30 . Device according to claim 25 , wherein the second cutting edge is configured to drill abrasive materials.

31 . Device according to claim 30 , wherein the second cutting edge is configured to drill carbon fiber composite materials, and is formed of a diamond comprising tungsten carbide or formed by a diamond tip attached to the drill bit.

32 . Device according to claim 25 , wherein the drill bit comprises three or four cutting edges; and wherein the chuck and the drill bit comprise distinct positions of the first axis relative to the axis of the drill bit for laterally offsetting the first axis relative to the axis of the drill bit in each of the directions opposite the directions of each of the three or four cutting edges.

33 . Device according to claim 25 , wherein the chuck comprises a rotating sleeve with an off-center hole, movable in rotation on the chuck around the first axis, inside which the drill bit is maintained with the axis of the drill bit on the second axis, the second axis being offset relative to the first axis so that a controlled rotation of the rotating sleeve turning inside a barrel of the chuck changes a direction, in a reference frame linked to the drill bit, in which the first axis is offset relative to the axis of the drill bit.

34 . Drill bit comprising at least two cutting edges forming a projecting conical end of the drill bit in rotation around an axis of the drill bit, a first cutting edge is configured to remove matter from a first material during drilling, and a second cutting edge is made differently from the first cutting edge, to remove matter from a second material during drilling, the second material being different from the first material.

35 . Drill bit according to claim 34 , wherein the first cutting edge and the second cutting edge are inclined in an axial plane of the drill bit so that they each form, with the axis of the drill bit, an angle between about 60 degrees and 45 degrees.

36 . Drill bit according to claim 34 , wherein the first cutting edge is configured to drill hard metals.

37 . Drill bit according to claim 36 , wherein the first cutting edge is formed of a tungsten carbide and is configured to drill titanium-based alloys.

38 . Drill bit according to claim 34 , wherein the second cutting edge is configured to drill abrasive materials.

39 . Drill bit according to claim 38 , wherein the second cutting edge is configured to rill carbon fiber composite materials, and is formed of a diamond comprising tungsten carbide or formed by a diamond tip attached to the drill bit.

40 . Drill bit according to claim 34 , comprising three or four cutting edges, each cutting edge being made differently from other cutting edges to remove matter from a different material during drilling.

41 . Drill bit according to claim 34 , wherein said at least two cutting edges are disposed on the drill bit to remove matter during drilling in opposite directions of rotation of the drill bit around the axis of the drill bit.

42 . Drill bit according to claim 34 , comprising one or more straight grooves oriented along the axis of the drill bit.

43 . Method for drilling through an assembly of pieces forming a stack of at least two materials having physical characteristics requiring different drilling conditions, using a drill bit with an axis, the drill bit comprising at least a first cutting edge and a second cutting edge inclined in an axial plane of the drill bit so that an end of the drill bit in rotation around the axis has a projecting conical shape, comprising the steps of:
drilling a first material using the first cutting edge; drilling a second material using the second cutting edge, which is made differently from the first cutting edge; placing and maintaining a first rotational drive axis of the drill bit, during the drilling, in lateral offset by an offset distance D relative to the axis of the drill bit; offsetting the first rotational drive axis by the offset distance D relative to the axis of the drill bit in a direction opposite the first cutting edge in response to the drill bit drilling through the first material; and offsetting the first rotational drive axis by the offset distance D relative to the axis of the drill bit in a direction opposite the second cutting edge in response to the drill bit drilling through the second material.

44 . Drilling method according to claim 43 , further comprising the step of limiting an advance, or a progression of the drill bit per rotation in an axial direction of the drilling, by an angle formed by each cutting edge relative to the axis of the drill bit and by the offset distance D so that only one cutting edge removes matter at a given time during the drilling.

45 . Drilling method according to claim 43 , further comprising the step of modifying cutting parameters in response to a change in a direction of the offset D during the drilling, the cutting parameters comprising at least a rotation speed and an advance of the drill bit.

46 . Drilling method according to claim 43 , further comprising the step of disposing at least one of the first cutting edge and the second cutting edge on the drill bit to remove matter in opposite directions of rotation of the drill bit; and reversing a direction of rotation of the drill bit based on a cutting edge utilized to drill through a material of the stack.

47 . Drilling method according to claim 43 , further comprising the step of determining a direction in which the first axis is offset by the offset distance D relative to the axis of the d

Assignees

• Airbus Group Sas

Inventors

• Vinhas Fernand
• Aliaga Daniel
• Abrivard Guillaume
• Schuster Dominique

Classifications

• B23B51/00

  Tools for drilling machines · CPC title

• B23B2251/14

  Configuration of the cutting part, i.e. the main cutting edges · CPC title

• B23B2226/31

  Diamond · CPC title

• B23B2222/88

  Titanium · CPC title

• B23B2226/275

  Carbon fibre reinforced carbon composites · CPC title