Systems, methods, and apparatuses for monitoring weld quality

• US 8,987,628 B2
• Filed: 10/03/2013
• Issued: 03/24/2015
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Original Assignee: Lincoln Global Incorporated (Lincoln Electric Holdings Incorporated)
• Inventors: Daniel, Joseph A., Chantry, Bruce J.
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): Nguyen, Cuong B
• Application Number:
  US14/044,986
• Publication Number:
  US 20140034617A1
• Time in Patent Office: 537 Days
• Field of Search: None
• US Class Current: 219/61.5
• CPC Class Codes: B23K 31/02 relating to soldering or welding dip or wave soldering in the manufacture of printed circuits H05K3/34
• CPC Class Codes: B23K 31/12 relating to investigating the properties, e.g. the weldability, of materials
• CPC Class Codes: B23K 9/095 Monitoring or automatic control of welding parameters
• CPC Class Codes: B23K 9/0953 using computing means
• CPC Class Codes: B23K 9/0956 using sensing means, e.g. optical
• CPC Class Codes: G09B 19/24 Use of tools

Abstract

An arc welder including an integrated monitor is disclosed. The monitor is capable of monitoring variables during a welding process and weighting the variables accordingly, quantifying overall quality of a weld, obtaining and using data indicative of a good weld, improving production and quality control for an automated welding process, teaching proper welding techniques, identifying cost savings for a welding process, and deriving optimal welding settings to be used as pre-sets for different welding processes or applications.

Claims

1. A monitor for monitoring an electric arc welder as the electric arc welder performs a selected arc welding process by creating actual welding parameters between an advancing wire and a workpiece to form a weld, said selected arc welding process being defined by a series of rapidly repeating wave shapes of command signals for said parameters, each wave shape constituting a weld cycle with a cycle time, said monitor comprising:

first logic for segmenting each of said wave shapes into a series of time segmented states;

second logic for selecting a specific wave shape state;

third logic for reading a plurality of selected weld parameters occurring in one or more of said states at an interrogation rate over a period of time repeated during the welding process;

fourth logic for calculating a plurality of quality parameters for each of said states based on said selected weld parameters;

fifth logic for comparing each of said quality parameters calculated for each period of time to a corresponding expected quality parameter to determine if a difference between said calculated quality parameter and said expected quality parameter exceeds a predetermined threshold; and

sixth logic for weighting said calculated quality parameter with a magnitude weight based on said difference, and weighting said calculated quality parameter with a time contribution weight based on a time contribution of its state to the wave shape including said state, if said difference exceeds said threshold,

wherein said quality parameters represent an overall quality measurement of said weld.

2. The monitor of claim 1, wherein said interrogation rate is 120 kHz.

3. The monitor of claim 1, wherein said period of time is approximately 250 ms.

4. The monitor of claim 1, wherein said selected weld parameters are read for all of said states.

5. The monitor of claim 1, further comprising:

using said quality parameters in a metric to evaluate subsequent welds.

6. A monitor for monitoring an electric arc welder as the electric arc welder performs a selected arc welding process by creating actual welding parameters between an advancing wire and a workpiece to form a weld, said selected arc welding process being defined by a series of rapidly repeating wave shapes of command signals for said parameters, each wave shape constituting a weld cycle with a cycle time, said monitor comprising:

first logic for segmenting each of said wave shapes into a series of time segmented states;

second logic for selecting a specific wave shape state;

third logic for reading a plurality of selected weld parameters occurring in one or more of said states at an interrogation rate over a period of time repeated during the welding process; and

fourth logic for calculating a plurality of quality parameters for each of said states based on said selected weld parameters,

wherein said selected weld parameters include, for each of said states, a count of said measurements taken for each of said selected weld parameters in said period of time, a mean voltage voltage in said period of time, a root mean square voltage RMSV in said period of time, a voltage variance V_var in said period of time, a mean current current in said period of time, a root mean square current RMSI in said period of time, and a current variance I_var in said period of time,

wherein voltage=a sum of voltages measured in said period of time/said count of voltage measurements,

wherein

7. The monitor of claim 6, wherein said quality parameters include a quality count average QCA for each state calculated as:

8. The monitor of claim 7, wherein said quality parameters include a quality count standard deviation QCSD for each state calculated as one of:

9. The monitor of claim 6, wherein said quality parameters include a quality voltage average QVA for each state calculated as:

10. The monitor of claim 9, wherein said quality parameters include a quality voltage standard deviation QVSD for each state calculated as one of:

11. The monitor of claim 6, wherein said quality parameters include a quality current average QIA for each state calculated as:

12. The monitor of claim 11, wherein said quality parameters include a quality current standard deviation QISD for each state calculated as one of:

13. The monitor of claim 6, wherein said quality parameters include a quality voltage variance average QVVA for each state calculated as:

14. The monitor of claim 13, wherein said quality parameters include a quality voltage variance standard deviation QVVSD for each state calculated as one of:

15. The monitor of claim 6, wherein said quality parameters include a quality current variance average QIVA for each state calculated as:

16. The monitor of claim 15, wherein said quality parameters include a quality current variance standard deviation QIVSD for each state calculated as one of: