Adaptive plasma cutting system and method

Patent metadata

Field	Value
Publication number	US-2017001255-A1
Application number	US-201514790767-A
Country	US
Kind code	A1
Filing date	Jul 2, 2015
Priority date	Jul 2, 2015
Publication date	Jan 5, 2017
Grant date	—

Abstract

A plasma torch system and method is provided, in which the system utilizes a number of pressure sensors throughout the system and the torch to detect the flow/pressure of shield and plasma gas during operation. The detected pressures are used by the system to dynamically control the system pressures to optimize the cutting operation.

First claim

What is claimed is:

1 . A plasma cutting system, comprising:
a gas flow control system having at least one gas flow valve which controls the flow a gas through said gas flow control system and a first gas pressure detection device which detects a first location pressure of said gas downstream of said at least one gas flow valve; a cutting torch assembly coupled to said gas flow control system to receive said gas, where said cutting torch assembly comprises a second gas pressure detection device which detects a second location pressure of said gas downstream of said first gas pressure detection sensor; and a controller coupled to each of said first and second gas pressure detection devices and to said at least one gas flow valve, where said controller controls an operation of said at least one gas flow valve based on gas pressure feedback signals from each of said first and second gas pressure detection devices to provide a desired pressure level of said gas at or within said cutting torch assembly, wherein said desired pressure level is determined by said controller based on at least one of a condition of said plasma cutting system and a parameter of a cutting operation, and wherein said gas is either a plasma gas or a shield gas.

2 . The plasma cutting system of claim 1 , wherein said second location pressure is a pressure of said gas flow as said gas enters said torch assembly.

3 . The plasma cutting system of claim 1 , wherein said second location pressure is in either a shield cavity pressure or a plasma chamber pressure of said torch assembly.

4 . The plasma cutting system of claim 1 , wherein said controller dynamically changes said desired pressure level during an operation of said plasma cutting system.

5 . The plasma cutting system of claim 1 , wherein said controller dynamically changes said desired pressure level during an operation of said plasma cutting system based on a detected gas flow profile for said plasma cutting system.

6 . The plasma cutting system of claim 6 , wherein said detected gas flow profile for said system is determined by said controller during a calibration of said plasma cutting system using said first and second gas pressure detection devices prior to the initiation of a cutting operation.

7 . The plasma cutting system of claim 1 , wherein said controller detects a type of a consumable coupled to said torch assembly based on feedback from said first and second gas pressure detection devices.

8 . The plasma cutting system of claim 1 , wherein when said controller detects a pressure differential between said first and second pressure locations that exceeds a predetermined threshold said controller interrupts a cutting operation of said plasma cutting system.

9 . The plasma cutting system of claim 1 , wherein said controller determines a pressure differential ratio between said first and second pressure locations and uses said pressure differential ratio to control said flow of said gas during a cutting operation.

10 . The plasma cutting system of claim 1 , wherein said controller uses said first and second gas pressure detection devices to determine a gas flow model for said plasma cutting system based on at least one of a position and orientation of said torch assembly.

11 . The plasma cutting system of claim 1 , wherein said second gas pressure detection device detects a cavity pressure within a cavity of said torch assembly, and where said second gas pressure detection device is positioned remotely from said cavity and is coupled to said cavity with a gas pressure detection channel.

12 . A plasma cutting system, comprising:
a gas flow control system having at shield gas flow valve which controls the flow a shield gas through said gas flow control system, a plasma gas flow valve which controls the flow of a plasma gas through said gas flow control system, a first shield gas pressure detection device which detects a first location pressure of said shield gas downstream of said shield gas flow valve, and first plasma gas pressure detection device which detects a first location pressure of said plasma gas downstream of said plasma gas flow valve; a cutting torch assembly coupled to said gas flow control system to receive each of said shield and plasma gas, where said cutting torch assembly comprises a second shield gas pressure detection device which detects a second location pressure of said shield gas downstream of said first shield gas pressure detection sensor, and a second plasma gas pressure detection device which detects a second location pressure of said plasma gas downstream of said first plasma gas pressure detection sensor; and a controller coupled to each of said first and second shield and plasma gas pressure detection devices and to said shield and plasma gas flow valves, where said controller controls an operation of said shield and plasma gas flow valves based on gas pressure feedback signals from each of said first and second shield and plasma gas pressure detection devices to provide a desired shield gas pressure level and a desired plasma gas pressure level at or within said cutting torch assembly, wherein said desired plasma and shield gas pressure levels are determined by said controller based on at least one of a condition of said plasma cutting system and a parameter of a cutting operation.

13 . The plasma cutting system of claim 12 , wherein said second shield and plasma gas location pressures are a pressure of each of said shield and plasma gas flows as said shield and plasma gases enter said torch assembly, respectively.

14 . The plasma cutting system of claim 12 , wherein said second shield gas location pressure is in a shield cavity of said torch assembly and said second plasma gas location pressure is in a plasma chamber of said torch assembly.

15 . The plasma cutting system of claim 12 , wherein said controller dynamically changes said desired pressure level for at least one of said plasma gas and said shield gas during an operation of said plasma cutting system.

16 . The plasma cutting system of claim 12 , wherein said controller dynamically changes said desired pressure level for each of said shield gas and said plasma gas during an operation of said plasma cutting system based on a detected shield gas flow profile and a detected plasma gas flow profile for said plasma cutting system.

17 . The plasma cutting system of claim 16 , wherein said detected plasma gas flow profile is determined by said controller during a calibration of said plasma cutting system using said first and second plasma gas pressure detection devices prior to the initiation of a cutting operation, and said detected shield gas flow profile is determined by said controller during a calibration of said plasma cutting system using said first and second shield gas pressure detection devices prior to the initiation of a cutting operation.

18 . The plasma cutting system of claim 12 , wherein said controller detects a type of a consumable coupled to said torch assembly based on feedback from at least one grouping of said first and second shield gas pressure detection devices and first and second plasma gas pressure detection devices.

19 . The plasma cutting system of claim 12 , wherein when said controller detects a shield gas pressure differential between said first and second shield gas pressure locations that exceeds a first predetermined threshold or detects a plasma gas differential between said first and second plasma gas pressure locations that exceeds a second predetermined

Assignees

• Lincoln Global Inc

Inventors

• Winn Jackie L

Classifications

• H05H1/34 Primary

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

• H05H1/26

  Plasma torches · CPC title

• B23K10/00

  Welding or cutting by means of a plasma · CPC title

• B23K10/006 Primary

  Control circuits therefor · CPC title

• H05H1/3405

  Arrangements for stabilising or constricting the arc, e.g. by an additional gas flow · CPC title