Method of determining a radius of a cutting end of a tool for a turning machine

Patent metadata

Field	Value
Publication number	US-9618927-B2
Application number	US-201414252910-A
Country	US
Kind code	B2
Filing date	Apr 15, 2014
Priority date	Apr 15, 2014
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A method of determining a radius of a cutting end of a tool for a turning machine using a touch probe is provided. One of the cutting end and the touch probe is movable relative to a reference frame having a first axis and a second axis and having a reference point trackable in the reference frame. The method comprises establishing a first contact point and recording a first coordinate of the reference point on the first axis; establishing a second contact point and recording a second coordinate of the reference point on the second axis; establishing a third contact point and recording a third coordinate of the reference point on the first axis and a fourth coordinate of the reference point on the second axis upon contact; and determining a radius of the cutting end based on the first, second, third and fourth coordinates.

First claim

The invention claimed is:

1. A method of determining with at least one electronic control unit a radius of a cutting end of a tool for a turning machine using a touch probe, one of the cutting end and the touch probe being movable as controlled by the at least one electronic control unit relative to a reference frame having a first axis and a second axis and having a reference point trackable in the reference frame of the at least one electronic control unit, the method comprising:
a) establishing, using the at least one electronic control unit, a first contact point between the touch probe and the cutting end and recording, using the at least one electronic control unit, a first coordinate of the reference point on the first axis, the first contact point having a known coordinate on the first axis; and
b) establishing, using the at least one electronic control unit, a second contact point between the touch probe and the cutting end and recording, using the at least one electronic control unit, a second coordinate of the reference point on the second axis, the second contact point having a known coordinate on the second axis; and
c) establishing, using the at least one electronic control unit, a third contact point between the touch probe and the cutting end by moving an end point of the one of the cutting end and the touch probe along a predetermined direction at an angle with the first and second axes as controlled by the at least one electronic control unit and recording, using the at least one electronic control unit, a third coordinate of the reference point on the first axis and a fourth coordinate of the reference point on the second axis upon contact, the pre-determined direction being dependent on the coordinate of the first contact point on the first axis and the coordinate of the second contact point on the second axis, the end point being offset from the reference point by an amount deduced from the first coordinate and the second coordinate recorded at steps a) and b); and
d) determining, using the at least one electronic control unit, a radius of the cutting end based on the first, second, third and fourth coordinates.

2. The method as defined in claim 1 , wherein steps a), b) and c) are performed within the turning machine.

3. The method as defined in claim 1 , wherein steps a) and b) are performed in any order.

4. The method as defined in claim 1 , wherein at least one of steps a), b) and c) is performed using a different touch probe.

5. The method as defined in claim 1 , wherein the probe is fixed relative to the reference frame and the cutting end is movable relative to the reference frame.

6. The method as defined in claim 1 , wherein determining the radius R of the tool comprises determining a radius R smaller than 0.1 inch.

7. The method as defined in claim 1 , wherein determining the radius R of the tool comprises determining a radius R between 0.01 and 0.1 inch.

8. The method as defined in claim 1 , wherein the predetermined direction is at 45degrees from the first and second axes.

9. The method as defined in claim 1 , wherein the first axis is an X-axis and the second axis is a Z-axis;
the predetermined direction is at an angle a from the X-axis and the Z-axis;
the reference point is P 0 ;
the known position of the first point of the one of the cutting edge and the touch probe on the X-axis is X 24 ;
step a) is performed at time t =t 1 ;
the first coordinate is P 0 t=t1 (X);
the known position of the second point of the one of the cutting edge and the touch probe on the Z-axis is Z 26 ;
step b) is performed at time t=t 2 ;
the second coordinate is P 0 t=t2 (Z);
the known position of the third point of the one of the cutting edge and the touch probe on the X-axis is Z 32 ;
step c) is performed at time t=t 3 ;
the third coordinate is P 0 t=t3 (X);
the known position of the third point of the one of the cutting edge and the touch probe on the Z-axis is Z 32 ;
the fourth coordinate is P 0 t=t3 (Z); and
the radius R is

R
=

(

1
+

2

)

⁢

(

P
0

t
=

t
⁢

⁢
3

⁡

(
X
)

-

P
0

t
=

t
⁢

⁢
1

⁡

(
X
)

+

X
24

-

X
32

)

2

+

(

P
0

t
=

t

Assignees

• Pratt & Whitney Canada

Inventors

• Gagnon Lafleche
• Guiassa Rachid
• St-Jacques Philippe

Classifications

• G05B2219/37405

  Contact detection between workpiece and tool, probe, feeler · CPC title

• G05B2219/37407

  Detect position of detector contact point relative to reference on tool · CPC title

• G05B2219/37406

  Detect position of detector contact point relative to reference on tool slide · CPC title

• G01B5/08

  for measuring diameters {(G01B5/0035 takes precedence; measuring radius of curvature G01B5/213)} · CPC title

• G05B2219/37404

  Orientation of workpiece or tool, surface sensor · CPC title