Plasma cutting machine and cutting method

Patent metadata

Field	Value
Publication number	US-9516737-B2
Application number	US-201314438358-A
Country	US
Kind code	B2
Filing date	Dec 25, 2013
Priority date	Dec 27, 2012
Publication date	Dec 6, 2016
Grant date	Dec 6, 2016

Abstract

A plasma torch is provided with an electrode for generating a plasma arc, a nozzle having an opening through which the plasma arc passes, and a cover member. The cover member is arranged to cover the nozzle in the jetting direction of the plasma arc from the nozzle. The cover member has an opening through which the plasma arc passes. The cover member is made from a magnetic material.

First claim

What is claimed is:

1. A plasma cutting machine comprising:
a table for mounting a member to be cut;
a plasma torch having an electrode for generating a plasma arc and a nozzle having an opening through which the plasma arc passes;
a moving device for moving the plasma torch over the table; and
a cover member made from a magnetic carbon steel material, disposed to cover the nozzle in a jetting direction of the plasma arc from the nozzle, and having an opening through which the plasma arc passes, the cover member suppressing magnetic arc blow.

2. The plasma cutting machine according to claim 1 , wherein
the cover member is disposed to overlap the nozzle as seen from the jetting direction of the plasma arc.

3. The plasma cutting machine according to claim 2 , wherein
a contour of the cover member is larger than a contour of the nozzle.

4. The plasma cutting machine according to claim 1 , wherein
a diameter of the opening in the cover member is larger than a diameter of the opening in the nozzle and smaller than an outer diameter of the nozzle.

5. The plasma cutting machine according to claim 1 , wherein
the cover member is a cap attached to a distal end part of the plasma torch.

6. The plasma cutting machine according to claim 5 , wherein
the cap is attached in a replaceable manner.

7. A plasma cutting machine comprising:
a table for mounting a member to be cut;
a plasma torch having an electrode for generating a plasma arc, a nozzle having an opening through which the plasma arc passes, and a shield cap arranged to cover the nozzle;
a moving device for moving the plasma torch over the table; and
the cover member comprising a metal plate made of a magnetic material, the cover member arranged facing a distal end part of the plasma torch in a jetting direction of the plasma arc from the nozzle, the cover member covering the nozzle and the shield cap in the jetting direction of the plasma arc, the cover member having an opening through which the plasma arc passes, the cover member suppressing magnetic arc blow.

8. The plasma cutting machine according to claim 7 , wherein
the metal plate is provided in a replaceable manner.

9. A plasma cutting machine comprising:
a table for mounting a member to be cut;
a plasma torch; and
a moving device for moving the plasma torch over the table;
the plasma torch including
an electrode for generating a plasma arc;
a nozzle having an opening through which the plasma arc passes; and
a cover member made from a magnetic carbon steel material, disposed to cover the nozzle in a jetting direction of the plasma arc from the nozzle, and having an opening through which the plasma arc passes, the cover member suppressing magnetic arc blow.

10. The plasma cutting machine according to claim 9 , wherein
the cover member is disposed to overlap the nozzle as seen from the jetting direction of the plasma arc.

11. The plasma cutting machine according to claim 10 , wherein
a contour of the cover member is larger than a contour of the nozzle.

12. The plasma cutting machine according to claim 9 , wherein
a diameter of the opening in the cover member is larger than a diameter of the opening in the nozzle and smaller than an outer diameter of the nozzle.

13. The plasma cutting machine according to claim 9 , wherein
the cover member is a shield cap disposed to cover a distal end part of the nozzle.

14. The plasma cutting machine according to claim 13 , wherein
the shield cap is provided in a replaceable manner.

15. A cutting method comprising:
attaching a cover member made from a magnetic material and having an opening through which a plasma arc passes onto a plasma torch having an electrode for generating the plasma arc and a nozzle having an opening through which the plasma arc passes, the cover member being attached to cover the nozzle in a jetting direction of the plasma arc from the nozzle;
cutting a member to be cut using the plasma torch; and
removing the cover member from the plasma torch and eliminating magnetism from the cover member.

Assignees

• Komatsu Ind Corp

Inventors

• Yamaguchi Yoshihiro
• Uesugi Yoshihiko
• Tanaka Yasunori
• Ishijima Tatsuo

Classifications

• B23K10/00 Primary

  Welding or cutting by means of a plasma · CPC title

• H05H1/34 Primary

  Details, e.g. electrodes, nozzles · CPC title

• H05H2001/3436

  Electricity · mapped topic

• B23K10/006

  Control circuits therefor · CPC title

• B23K37/0408

  for planar work · CPC title