Method and apparatus for determining a hole depth

Patent metadata

Field	Value
Publication number	US-2016178343-A1
Application number	US-201514974093-A
Country	US
Kind code	A1
Filing date	Dec 18, 2015
Priority date	Dec 19, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A method of determining a depth of a hole formed in a work piece is disclosed. The method includes determining the hole depth based upon a load signal indicative of a load on a tool forming the hole during the forming of the hole. The hole depth determined is then adjusted with an offset and component specifications are combined with the hole length to determine a component specification for use in the hole to fix components together. At least a part of the depth determination and component specification can be carried out automatically in a computer, for an array of holes.

First claim

1 . A method of determining a length for a component to be located in a machined hole, comprising the steps of:
using a machine to form at least one hole in a work piece, from a first surface of the work piece, through the work piece, to a second surface of the work piece; monitoring a tool load signal, indicative of a load on a tool of the machine, during the forming of the hole; determining from the tool load signal a depth of the hole, from the first surface of the work piece to the second surface of the work piece; and determining, based upon the determined hole depth, a specified length for a component to be located in the hole, wherein determining the hole depth includes setting a tool breakthrough threshold value for the tool load signal, substantially at or below which the tool is determined to have penetrated an opposite surface of the work piece.

2 . A method according to claim 1 , further comprising forming an array of holes in the work piece.

3 . A method according to claim 1 , wherein the work piece is an assembly comprising plural components to be fixed together using fixing means to be located in the holes to be drilled.

4 . A method according to claim 3 , wherein the work piece comprises a plurality of layers of sheet material.

5 . A method according to claim 1 , wherein the work piece comprises a wing component of an aircraft.

6 . A method according to claim 1 , wherein determining the hole depth comprises applying an offset value to a calculated hole depth determined from the tool load signal.

7 . A method according to claim 6 , wherein the offset value is selected based upon properties of the material or materials of the work piece.

8 . A method according to claim 6 , wherein the offset value is selected based upon properties of the tool.

9 . A method according to claim 1 , wherein the step of determining the hole depth comprises determining a threshold above which the tool load indicates that the hole is being formed and determining a length over which the load remains above the threshold.

10 . The method according to claim 1 , wherein the tool breakthrough threshold value is determined based upon a value of the tool load signal before breakthrough.

11 . The method according to claim 1 , wherein the tool breakthrough threshold value is determined based upon a value of the tool load signal after breakthrough.

12 . The method according to claim 11 , wherein the tool breakthrough threshold value is determined based upon a difference between the value of the tool load signal before breakthrough and the value of the tool load signal after breakthrough.

13 . The method according to claim 1 , wherein the tool breakthrough threshold value is determined based upon an average of the load signal before breakthrough.

14 . The method according to claim 1 , wherein the tool breakthrough threshold value is determined based upon an average of the load signal after breakthrough.

15 . An electronic device arranged to determine a depth of a hole drilled in a work piece, from a first surface of the work piece, to a second surface of the work piece, based upon a tool load signal, indicative of a load on a tool of a hole forming machine during the forming of the hole by the machine, wherein determining the hole depth includes setting a tool breakthrough threshold value for the tool load signal, substantially at or below which the tool is determined to have penetrated an opposite surface of the work piece.

16 . An electronic device according to claim 15 , wherein the device is further configured to determine, based upon the determined hole depth, a specified length for a component to be located in the hole.

17 . An electronic device according to claim 15 , wherein determining the hole depth comprises applying an offset value to a hole depth calculated from the tool load signal.

18 . An electronic device according to claim 17 , wherein the offset value is selected based upon properties of the material or materials of the work piece.

19 . An electronic device according to claim 17 , wherein the offset value is selected according to properties of the tool.

20 . An electronic device according to claim 15 , wherein the step of determining the hole depth comprises determining a threshold above which the tool load indicates that the hole is being formed and determining a length over which the load remains above the threshold.

Assignees

• Airbus Operations Ltd

Inventors

• Hale Greg Andrew
• Landeg Gareth William
• Godfrey Matthew Lee
• Clayton Richard James
• Hall David John

Classifications

• B23Q17/20 Primary

  for indicating or measuring workpiece characteristics, e.g. contour, dimension, hardness · CPC title

• B23Q17/0952

  during machining · CPC title

• B23B2260/0487

  Depth indicators · CPC title

• B23B35/00 Primary

  Methods for boring or drilling, or for working essentially requiring the use of boring or drilling machines; Use of auxiliary equipment in connection with such methods · CPC title

• B23B2270/32

  Use of electronics · CPC title