Systems and methods for ultrasonic welding

Patent metadata

Field	Value
Publication number	US-10105789-B2
Application number	US-201615236921-A
Country	US
Kind code	B2
Filing date	Aug 15, 2016
Priority date	Jun 5, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

Systems and methods to improve weld quality are described. For example, certain systems and methods described use weld quality monitoring as feedback to an ultrasonic welding process to improve weld quality. Still other systems and methods provide improvement to double sided and single sided ultrasonic welding through the use of selected multiple pulses.

First claim

The invention claimed is:

1. A method, comprising:
determining fit-up conditions including a material of workpieces;
determining a threshold weld strength value;
accessing weld strength data, the weld strength data including a plurality of values of weld strength and a plurality of values of welding parameters, each of the plurality of values of weld strength corresponding to:
a value of a first welding parameter of a first pulse of ultrasonic vibration; and
a value of a second welding parameter of a second pulse of ultrasonic vibration;

determining a weld schedule, comprising:
selecting a first value of the first welding parameter of the first pulse of ultrasonic vibration; and
selecting a second value of the second welding parameter of the second pulse of ultrasonic vibration;

wherein each of the first value of the first welding parameter and the second value of the second welding parameter is selected based on:
the weld strength data;
the threshold weld strength value; and
minimizing at least one of the first value of the first welding parameter and the second value of the second welding parameter; and

applying, by a welding horn according to the weld schedule:
the first pulse of ultrasonic vibration to workpieces, the first pulse having the first welding parameter; and
after a cooling period, the second pulse of ultrasonic vibration to the workpieces, the second pulse having the second welding parameter.

2. The method of claim 1 , wherein at least one of the first welding parameter and the second welding parameter is welding energy.

3. The method of claim 1 , wherein at least one of the first welding parameter and the second welding parameter is welding time.

4. The method of claim 1 , wherein at least one of the first welding parameter and the second welding parameter is welding pressure.

5. The method of claim 1 , wherein the fit-up conditions further comprise a thickness of the workpieces.

6. The method of claim 1 , wherein the weld strength data is determined based on the fit-up conditions.

7. The method of claim 1 , wherein:
at least some of the values of the plurality of values of weld strength correspond to a value of a third welding parameter of a third pulse of ultrasonic vibration;
determining the weld schedule comprises selecting a third value of the third welding parameter of the third pulse of ultrasonic vibration; and
wherein the value of the third welding parameter is selected based on:
the weld strength data;
the threshold weld strength value; and
minimizing at least one of the first value of the first welding parameter, the second value of the second welding parameter, and the third value of the third welding parameter; and

applying, by the welding horn, after a second cooling period, the third pulse of ultrasonic vibration to the workpieces, the third pulse having the third welding parameter.

8. The method of claim 1 , comprising positioning an overlapping portion of the workpieces between the welding horn and an anvil.

9. The method of claim 1 , wherein the first pulse is applied until a measured value meets or exceeds the first value of the first welding parameter.

10. The method of claim 9 , the second pulse is applied until a measured value meets or exceeds the second value of the second welding parameter.

11. A welding system, comprising:
a welding horn; and
a controller, comprising:
a processor; and
a memory, comprising:
weld strength data including a plurality of values of weld strength and a plurality of values of welding parameters, each of the plurality of values of weld strength corresponding to:
a value of a first welding parameter of a first pulse of ultrasonic vibration; and
a value of a second welding parameter of a second pulse of ultrasonic vibration;

computer executable instructions that, when executed by the processor, cause the processor to perform operations comprising:
determining fit-up conditions including a material of workpieces;
determining a threshold weld strength value;
accessing the weld strength data,
determining a weld schedule, comprising:
 selecting a first value of the first welding parameter of the first pulse of ultrasonic vibration; and
 selecting a second value of the second welding parameter of the second pulse of ultrasonic vibration;
 wherein each of the first welding parameter and the second welding parameter is selected based on:
 the weld strength data;
 the threshold weld strength value; and
 minimizing at least one of the first value of the first welding parameter and the second value of the second welding parameter; and
applying, by the welding horn according to the weld schedule:
 the first pulse of ultrasonic vibration to workpieces; and
 after a cooling period, the second pulse of ultrasonic vibration to the workpieces.

12. The system of claim 11 , wherein at least one of the first welding parameter and the second welding parameter is welding energy.

13. The system of claim 11 , wherein at least one of the first welding parameter and the second welding parameter is welding time.

14. The system of claim 11 , wherein at least one of the first welding parameter and the second welding parameter is welding pressure.

15. The system of claim 11 , wherein the fit-up conditions further comprise a thickness of the workpieces.

16. The system of claim 11 , wherein the weld strength data is determined based on the fit-up conditions.

17. The system of claim 11 , wherein the first pulse is applied until a measured value meets or exceeds the first value of the first welding parameter.

18. The system of claim 17 , the second pulse is applied until a measured value meets or exceeds the second value of the second welding parameter.

19. A controller, comprising:
a processor; and
a memory, comprising:
weld strength data including a plurality of values of weld strength and a plurality of values of welding parameters, each of the plurality of values of weld strength corresponding to:
a value of a first welding parameter of a first pulse of ultrasonic vibration; and
a value of a second welding parameter of a second pulse of ultrasonic vibration;

computer executable instructions that, when executed by the processor, cause the processor to perform operations comprising:
determining fit-up conditions including a material of workpieces;
determining a threshold weld strength value;
accessing the weld strength data,
determining a weld schedule, comprising:
selecting a first value of the first welding parameter of the first pulse of ultrasonic vibration; and
selecting a second value of the second welding parameter of the second pulse of ultrasonic vibration;
wherein each of the first welding parameter and the second welding parameter is selected based on:
 the weld strength data;
 the threshold weld strength value; and
 minimizing at least one of the first value of the first welding parameter and the second value of the second welding parameter; and

applying, by a welding horn according to the weld schedule:
the first pulse of ultrasonic vibration to workpieces; and
after a cooling period, the second pulse of ultrasonic vibration to the workpieces.

20. The controller of claim 19 , wherein at least one of the first welding parameter and the second welding parameter is welding energy.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Wang Pei-Chung
• Smyth Susan M
• Liu Zhongxia

Classifications

• B29C66/92211

  with special measurement means or methods · CPC title

• B29K2077/00

  Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material · CPC title

• B29C66/91231

  of the joining tool · CPC title

• B29C66/92921

  in specific relation to time, e.g. pressure-time diagrams · CPC title

• B29C65/08

  using ultrasonic vibrations {(non-plastics element to plastics elements B29C65/645)} · CPC title