Drawing machine for drawing tubes

Patent metadata

Field	Value
Publication number	US-10328473-B2
Application number	US-201414787449-A
Country	US
Kind code	B2
Filing date	Nov 20, 2014
Priority date	Nov 20, 2013
Publication date	Jun 25, 2019
Grant date	Jun 25, 2019

Abstract

A drawing machine (1) for drawing a tube (2), defining a longitudinal axis (Y), comprising a first die (3) for carrying out the drawing of the tube by means of the use of a mandrel (4); a device for varying the inclination (5) of the tube inlet into said first die (3); a second die (6) for carrying out a skin pass operation on the tube, arranged downstream of said first die (3); an in-line system for detecting the eccentricity of the tube; a data processing system (7) for processing signals originating from said detection system and sending input data to said device for varying the inclination (5) of the tube to vary the inclination of the tube so as to correct the eccentricity of the tube in-line; wherein said in-line system for detecting the eccentricity of the tube comprises a first detection head comprising at least three first transducers (8) arranged downstream of said first die (3).

First claim

The invention claimed is:

1. A drawing machine for drawing a tube, defining a longitudinal axis, comprising:
a first die for carrying out a drawing of the tube by means of a mandrel;
an inclination variation device for varying the inclination of the tube entering into said first die;
an in-line detection system for detecting an eccentricity of the tube;
a data processing system for processing signals originating from said in-line detection system and sending input data to said inclination variation device to vary the inclination of the tube so as to correct the concentricity of the tube in-line;

characterized in that there is provided a second die for carrying out a skin pass operation on the tube, which is arranged downstream of said first die, and in that said in-line detection system comprises a first detection head arranged downstream of said first die and comprising at least three first transducers.

2. A drawing machine according to claim 1 , wherein said first detection head is arranged in a die holder of said second die.

3. A drawing machine according to claim 2 , wherein said in-line detection system further comprises another first detection head arranged downstream of said first die and comprising at least three first transducers, said another first detection head arranged in a chamber, coaxial to the longitudinal axis, provided between a die holder of said first die and the die holder of said second die.

4. A drawing machine according to claim 1 , wherein said in-line detection system comprises a second detection head, arranged downstream of said second die, comprising at least three second transducers.

5. A drawing machine according to claim 4 , wherein said second detection head is provided downstream of a caterpillar on which said first die and said second die are arranged.

6. A drawing machine according to claim 4 , wherein said second transducers are of the ultrasonic type and are angularly equidistant from each other.

7. A drawing machine according to claim 1 , wherein said first transducers are of the ultrasonic type and are angularly equidistant from each other.

8. A drawing machine according to claim 1 , wherein one end of said first transducers is in contact with a first channel, which is coaxial to the longitudinal axis and is provided in a die holder of said second die, for the passage of a coupling medium.

9. A drawing machine according to claim 8 , wherein there is provided a second channel, which is coaxial to the longitudinal axis and is made in the die holder of said second die, for the passage of a cooling fluid next to said first transducers.

10. A drawing machine according to claim 8 , wherein the coupling medium is oil.

11. A drawing machine according to claim 1 , wherein said inclination variation device comprises two self-centering gripper heads, each gripper head having four rollers arranged at 90° from each other.

12. A drawing machine according to claim 1 , wherein said first detection head is arranged in a chamber, coaxial to the longitudinal axis, provided between a die holder of said first die and the die holder of said second die.

13. An in-line method for correcting an eccentricity of a tube during a drawing thereof, by means of a drawing machine according to claim 1 , the method comprising the following stages:
drawing the tube by means of the first die;
carrying out a skin pass operation on the tube by means of the second die;
carrying out a first in-line detection of the eccentricity of the tube by means of the first detection head;
processing signals originating from said first detection head by means of the data processing system and sending input data to the inclination variation device so as to vary the inclination of the tube with respect to the longitudinal axis and to correct the eccentricity of the tube in-line.

14. An in-line method according to claim 13 , wherein there is provided a second in-line detection of the eccentricity of the tube by means of a second detection head arranged downstream of said second die, the method further comprising processing signals originating from said second detection head by means of the data processing system and sending further input data to the inclination variation device.

15. An in-line method according to claim 13 , wherein said first in-line detection of the eccentricity of the tube is provided at said second die.

16. An in-line method according to claim 15 , wherein there is provided a second in-line detection of the eccentricity of the tube by means of a second detection head arranged downstream of said second die, the method further comprising processing signals originating from said second detection head by means of the data processing system and sending further input data to the inclination variation device.

17. An in-line method according to claim 15 , wherein said first in-line detection of the eccentricity of the tube is further provided at an area arranged downstream of said first die and upstream of said second die.

18. An in-line method according to claim 17 , wherein there is provided a second in-line detection of the eccentricity of the tube by means of a second detection head arranged downstream of said second die, the method further comprising processing signals originating from said second detection head by means of the data processing system and sending further input data to the inclination variation device.

19. An in-line method according to claim 13 , wherein said first in-line detection of the eccentricity of the tube is provided at an area arranged downstream of said first die and upstream of said second die.

20. An in-line method according to claim 19 , wherein there is provided a second in-line detection of the eccentricity of the tube by means of a second detection head arranged downstream of said second die, the method further comprising processing signals originating from said second detection head by means of the data processing system and sending further input data to the inclination variation device.

Assignees

• Danieli Off Mecc

Inventors

• Angelilli Andrea
• Crespan Luca

Classifications

• B21C1/24

  by means of mandrels · CPC title

• B21C51/00 Primary

  Measuring, gauging, indicating, counting, or marking devices specially adapted for use in the production or manipulation of material in accordance with subclasses B21B - B21F · CPC title

• B21C3/14

  Die holders combined with devices for guiding the drawing material or combined with devices for cooling, heating, or lubricating · CPC title