Systems and methods to reduce air pocket formation during welding

Patent metadata

Field	Value
Publication number	US-2016167288-A1
Application number	US-201414568792-A
Country	US
Kind code	A1
Filing date	Dec 12, 2014
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

The present technology discloses a system, for joining workpieces using energy, such as ultrasonic energy, where the energy concentrates at a location within a weld area, promoting sequential melting of a plurality of energy directors. The system can be configured so that the sequential melting begins at the center of the weld area and progresses outwards. Sequential melting may occur through use of a welding tip configured to reduce air pockets, a tapering the height of a plurality of energy directors, and/or tapering the energy directors themselves, all of which reduce the size of an energy transfer area produced by thermal energy. The present technology also includes a method for joining workpieces using energy such as ultrasonic energy that concentrates at a location within a weld area causing sequential melting of a plurality of energy directors using the aforementioned features.

First claim

What is claimed is:

1 . A method, for joining a first workpiece and a second workpiece, comprising:
providing the first workpiece, the second workpiece, and a plurality of energy directors, yielding a system, wherein the energy directors are configured and positioned between the first workpiece and the second workpiece for being melted sequentially in response to application of energy to the system; and applying energy to at least one of the workpieces, melting the plurality of energy directors sequentially, forming a substantially void-free weld between the first workpiece and the second workpiece.

2 . The method of claim 1 wherein the first workpiece is configured to receive the energy applied and at least one of the plurality of energy directors is positioned at an first interface surface of the first workpiece.

3 . The method of claim 1 wherein the energy directors, in being configured to melt sequentially, are configured so that the energy applied generally concentrates initially at a center portion of a weld area at which the first workpiece and second workpiece are joined using the energy directors.

4 . The method of claim 1 wherein the energy directors, in being configured to melt sequentially, comprise at least one of the energy directors having a tapered height.

5 . The system of claim 1 wherein the energy directors, in being configured to melt sequentially, comprise a first energy director comprising a first material and a second energy director comprising a second material such that the energy applied generally concentrates initially at the first energy director comprising the first material based on a difference between the first material and the second material.

6 . The method of claim 1 wherein the energy directors, in being configured to melt sequentially, comprise at least one first energy director having a first height being greater than heights of remaining energy directors of the plurality of energy directors, so that the energy applied generally concentrates initially at the first energy director having the first height before reaching the remaining energy directors.

7 . The method of claim 6 wherein the energy directors, in being configured to melt sequentially, comprise at least one of the remaining energy directors having a second height being less than the first height and being positioned adjacent the first energy director having the first height.

8 . The method of claim 1 wherein applying the energy comprises applying the energy using a hemispherical welding tip configured to promote concentration of energy emitted from the hemispherical welding tip toward at least one of the energy directors.

9 . A system, for joining a first workpiece and a second workpiece, comprising:
a plurality of energy directors configured to be positioned at one of a first interface surface of the first workpiece and a second interface surface of the second workpiece, for joining together, by a substantially void-free weld in a weld area of the system, the first interface surface of the first workpiece and the second interface surface of the second workpiece during operation of the system, wherein the energy directors, in being configured to be positioned at one of the first interface surface and the second interface surface for joining the first interface surface and the second interface surface, are configured to melt sequentially in response to application of input energy to form the substantially void-free weld within the weld area during operation of the system.

10 . The system of claim 9 further comprising the first workpiece and the second workpiece, wherein the first workpiece is configured to receive the input energy and at least one of the plurality of energy directors is positioned at the first interface surface of the first workpiece.

11 . The system of claim 9 wherein the energy directors, in being configured to melt sequentially, are configured so that the input energy generally concentrates initially at a center portion of the weld area.

12 . The system of claim 9 wherein the energy directors being configured to melt sequentially comprises at least one of the energy directors having a tapered height.

13 . The system of claim 9 wherein the energy directors, in being configured to melt sequentially, comprise a first energy director comprising a first material and a second energy director comprising a second material such that the input energy generally concentrates initially at the first energy director comprising the first material based on a difference between the first material and the second material.

14 . The system of claim 9 wherein the energy directors, in being configured to melt sequentially, comprises a first energy director of the energy directors, having a first height being greater than heights of remaining energy directors of the plurality of energy directors, so that the input energy generally concentrates initially at the first energy director having the first height before reaching the remaining energy directors.

15 . The system of claim 14 wherein the energy directors being configured to melt sequentially comprises at least one of the remaining energy directors having a second height being less than the first height, is positioned adjacent the first energy director having the first height.

16 . The system of claim 9 wherein the system comprises a hemispherical welding tip configured to promote concentration of energy emitted from the hemispherical welding tip toward at least one of the energy directors.

17 . A system, for joining a first workpiece and a second workpiece, comprising:
a first energy director having a first height; and a second energy director having a second height, being less than the first height, and configured to be positioned adjacent the first energy director, wherein the first energy director and the second energy director are configured to be positioned at one of a first interface surface of the first workpiece and a second interface surface of the second workpiece to join the first interface surface and the second interface surface and configured to melt sequentially in response to application of input energy to the system to form a substantially void-free weld within a weld area during operation of the system.

18 . The system of claim 17 further comprising the first workpiece and the second workpiece, wherein the first workpiece is configured to receive the input energy and at least one of the plurality of energy directors is positioned at the first interface surface of the first workpiece.

19 . The system of claim 17 wherein the energy directors, in being configured to melt sequentially, are configured so that the input energy generally concentrates initially at a center portion of the weld area.

20 . The system of claim 17 wherein the system comprises a hemispherical welding tip configured to promote concentration of energy emitted from the hemispherical welding tip toward the first energy director.

Assignees

• Gm Global Tech Operations Inc

Inventors

• Rodgers William A
• Kia Hamid G

Classifications

• B29C65/7443

  by means of ultrasonic vibrations · CPC title

• B29C66/342

  Preventing air-inclusions · CPC title

• B29C65/08 Primary

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

• B29C66/81422

  being convex · CPC title

• B29K2105/124

  Nanofibers · CPC title