Drilling tool and device for drilling with cryogenic cooling and method for drilling a stack of heterogeneous materials

Patent metadata

Field	Value
Publication number	US-10124416-B2
Application number	US-201615348135-A
Country	US
Kind code	B2
Filing date	Nov 10, 2016
Priority date	Sep 21, 2012
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A drill bit having an interior canal for liquid nitrogen to pass longitudinally through the body of the drill bit. The canal has, on the side of a cutting edge of the drill bit, at least one liquid nitrogen ejection duct that opens near the cutting edge which is formed by an insert made with polycrystalline diamond fixed to the body of the drill bit. A device for drilling a metal-composite stack includes the drill bit, a liquid nitrogen production unit and a distribution network to distribute the liquid nitrogen. The device drills through a metal-composite stack in a single pass of the drill bit. The liquid nitrogen at cryogenic temperature is conveyed close to the cutting edge, at least while the cutting edge is in contact with the metallic material.

First claim

The invention claimed is:

1. A drilling method for drilling a stack comprising at least one layer of a metal material comprising titanium and at least one layer of a composite material comprising fibers held in a hardened matrix, the method comprising the steps of:
drilling the stack in one pass with a drill bit comprising at least one cutting edge formed by an insert made with polycrystalline diamond and attached to a body of the drill bit so as to form the at least one cutting edge; and
transporting liquid nitrogen at cryogenic temperature and ambient pressure close to said at least one cutting edge in contact with the metal material through a channel passing internally through the body of the drill bit and through at least one ejection duct that opens close to said at least one cutting edge.

2. The drilling method as claimed in claim 1 , further comprising the step of transporting the liquid nitrogen simultaneously on a cutting face and on a wear face of said at least one cutting edge.

3. The drilling method as claimed in claim 1 , further comprising the step of transporting the liquid nitrogen into the channel as a function of a measured or estimated position of the drill bit with respect to the stack.

4. The drilling method as claimed in claim 1 , wherein the metal material of the stack comprises a titanium-based alloy; and further comprising the step of transporting the liquid nitrogen with a flow rate sufficient to keep a temperature of the drill bit below a temperature for converting the polycrystalline diamond into graphite.

5. The drilling method as claimed in claim 1 , further comprising:
insulating the body of the drill bit from the liquid nitrogen within the channel.

Assignees

• Airbus Sas

Inventors

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

Classifications

• B23B51/0493 Primary

  with exchangeable cutting inserts, e.g. able to be clamped · CPC title

• Y10T408/45

  including Tool with duct · CPC title

• Y10T408/03

  Processes · CPC title

• B23B2228/36

  Multi-layered · CPC title

• B23B2226/315

  polycrystalline [PCD] · CPC title