Method for controlling weld energy

• US 20070119823A1
• Filed: 11/30/2005
• Published: 05/31/2007
• Est. Priority Date: 11/30/2005
• Status: Active Grant

• Current Assignee: Ford Motor Company
• Original Assignee: Ford Motor Company
• Inventors: Filev, Dimitar, Hanel, Tamara, Chesney, Dave, El banna, Mahmoud
• Granted Patent: US 7,759,596 B2
• Time in Patent Office: Days
• US Class Current: 219/110
• CPC Class Codes: B23K 11/252 using digital means

Abstract

A method for controlling weld energy used in a welding process. The method includes establishing a weld energy profile having a total weld energy used over the period of the weld cycle. During the welding process, the expulsion rate is monitored and used to modify the weld energy. Based on the expulsion rate occurring during the welding process, the total weld energy can be shifted between various phases or cycles. In addition, the overall amount of or total weld energy can be increased and decreased.

Claims

1. A method for controlling weld energy used in a welding process comprising the steps of:

establishing an energy profile used over the period of the weld cycle to perform the welding process;

monitoring the expulsion rate during the welding process;

modifying the established energy profile based on the expulsion rate; and

using the modified energy profile to perform the welding process.

2. The method of claim 1 wherein the step of monitoring the expulsion rate during the welding process includes determining when during the welding cycle the expulsion occurs.

3. The method of claim 1 wherein the step of establishing an energy profile used over the period of the weld cycle includes creating a target factored energy profile used to calculate a total factored energy needed to produce the weld;

and

partitioning the total factored energy into a first part and a second part.

4. The method of claim 3 including the step of using the melting point of a weldment to determine the partition point used to divide the total factored energy into the first part and the second part.

5. The method of claim 4 wherein the step of monitoring the expulsion rate during the welding process includes determining whether the expulsion occurs during the first part or the second part of the total factored energy of the welding cycle.

6. The method of claim 5 including the step of shifting the target factored energy profile based on the expulsion rate occurring in the first and second parts of the total factored energy.

7. The method of claim 5 wherein the step of shifting the target factored energy includes the step of increasing the total factored energy in the second part when the expulsion rate occurrence in the first part exceeds predetermined threshold.

8. The method of claim 5 wherein the step of shifting the target factored energy includes the step of increasing the total factored energy in the first part when the expulsion rate occurrence in the second part exceeds predetermined threshold.

9. The method of claim 5 wherein the step of shifting the target factored energy includes the step of adjusting the total factored energy and both the first part and the second part of the total factored energy based upon the expulsion rate occurring in both the first part and second part of the total factored energy.

10. The method of claim 9 including the step of lowering the overall total factored energy when the rate of expulsion occurrence in the first part and second part exceeds a predetermined threshold.

11. The method of claim 9 including the step of raising the overall total factored energy when the rate of expulsion occurrence in the first part and second part is below a predetermined threshold.

12. A method for controlling weld energy used to create a weld during a welding process comprising:

establishing a total factored energy needed to produce a satisfactory weld and providing an energy profile based on the total factored energy;

partitioning the total factored energy into a first part and a second part;

performing a welding process and monitoring expulsion occurrence during the first part and the second part;

adaptively changing the total factored energy based on the expulsion occurrence.

13. The method of claim 12 wherein adaptively changing the total factored energy based on the expulsion occurrence includes the step of shifting the target factored energy between the first part and the second part.

14. The method of claim 12 wherein adaptively changing the total factored energy based on the expulsion occurrence includes the step of increasing the target factored energy.

15. The method of claim 12 wherein adaptively changing the total factored energy based on the expulsion occurrence includes the step of decreasing the target factored energy.

16. A method for controlling weld energy used to create a weld during a welding process comprising:

establishing a total factored energy needed to produce a satisfactory weld and providing an energy profile based on the total target factored energy;

partitioning the total factored energy into a first part and a second part;

performing a welding process and monitoring expulsion occurrence during the first part and the second part;

inputting expulsion occurrence rates into a fuzzy logic controller with associated fuzzy inference rules defining total factored energy control actions depending on various combinations of expulsion occurrence rates;

analyzing expulsion occurrence rates in accordance with the fuzzy inference rules to determine appropriate total factored energy control actions;

generating total factored energy adjustment parameters defining adjustments to the total factored energy; and

applying total factored energy adjustment parameters to adjust the total factored energy.

17. The method of claim 16 wherein the step of generating total factored energy adjustment parameters includes the step of generating an adjustment factor for adjusting the total energy factor.

18. The method of claim 16 wherein the step of generating total factored energy adjustment parameters includes the step of generating an adjustment factor for adjusting the factored energy in the first part and the second part of the total factored energy.

19. The method of claim 16 wherein the step of generating total factored energy adjustment parameters includes the step of shifting the factored energy between the first part and second part of the total factored energy.

20. The method of claim 16 wherein the step of partitioning the total factored energy into a first part and a second part includes the step of establishing a partition point, wherein the partition point divides the total factored energy into the first part and the second part;

and

the step of generating total factored energy adjustment parameters includes the step of shifting the position of the partition point.