Method of reducing cycle time for flow drill screw operations

Patent metadata

Field	Value
Publication number	US-10239112-B2
Application number	US-201514883782-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Oct 15, 2015
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A method of reducing the cycle time required for flow-drill screw operations by providing a dimple on a part that is engaged by a flow-drill screw. A tip of the flow-drill screw engages a contact band at a location spaced from the tip of the distal end of the flow-drill screw and base portion of the dimple. Friction between the flow-drill screw tip and dimple creates a heat concentration area and results in displaced material forming a threaded sleeve. The flow-drill screw is secured by the threads of the threaded sleeve to secure the top part to the bottom part.

First claim

What is claimed is:

1. A part assembly method comprising:
forming a dimple on an insertion side and a protrusion on a contact side of a first part before assembling the first part to a second part;
inserting a flow-drill screw into the first part with the protrusion contacting the second part; and
rotating the flow-drill screw to drive the flow drill screw through the dimple and the second part to secure the first part to the second part.

2. The method of claim 1 , wherein the dimple is conically shaped.

3. The method of claim 2 wherein the dimple has a sidewall disposed at an angle of between 30° and 60° relative to a surface adjacent the dimple on the insertion side of the first part.

4. The method of claim 1 , wherein the flow-drill screw has a convexly curved tip that initially engages the dimple at a location spaced above a base area of the of the dimple.

5. The method of claim 1 , wherein the dimple is an elongated slot that includes tapered sides extending from the insertion side of the first part to a base area.

6. The method of claim 1 , wherein adhesive is applied between the contact side of the first part and the second part.

7. The method of claim 6 wherein the protrusion penetrates the adhesive, and wherein heat is directly transferred from the protrusion to the second part, minimizing the extent that the adhesive thermally insulates the second part from heat developed in the protrusion.

8. The method of claim 1 wherein the dimple has sides that extend at an angle of between 30 and 60 degrees.

9. The method of claim 1 wherein the dimple has a lead-in surface between the sides and the insertion side.

10. An assembly method comprising:
forming a dimple having a conical sidewall on a part;
assembling the part to a second part;
providing a screw having a tip on a distal end and a convex sidewall;
heating a contact band on the conical sidewall by rotating the convex sidewall against the contact band with the tip spaced from the part; and
driving the tip into the part and the second part after heating the contact band.

11. The method of claim 10 , wherein the dimple is a conically shaped recess.

12. The method of claim 11 wherein the dimple has a sidewall disposed at an angle of between 30° and 60° relative to a surface adjacent the dimple on the insertion side of the first part.

13. The method of claim 10 , wherein the screw has a convexly curved tip that initially engages the dimple at the contact band at a location spaced above a base area of the of the dimple.

14. The method of claim 1 , wherein adhesive is applied between the contact side of the part and the second part.

15. The method of claim 14 wherein a protrusion is formed on a side of the part opposite the dimple, wherein the protrusion penetrates the adhesive, and wherein heat is directly transferred from the protrusion to the second part, minimizing the extent that the adhesive thermally insulates the second part from heat transferred from the protrusion.

16. An assembly method comprising:
forming an elongated recess including tapered sides extending from an insertion side of a part to a base area;
assembling the part to a second part;
providing a screw having a tip on a distal end and a convex sidewall;
heating a contact area on the tapered sides by rotating the convex sidewall against the contact area with the tip spaced from the base area; and
driving the tip into the base area and the second part after heating the contact band.

17. The method of claim 16 wherein tapered sides of the elongated recess each extend at an angle of between 30 and 60 degrees relative to a surface of the part adjacent the elongated recess.

Assignees

• Ford Global Tech Llc

Inventors

• Norton Thomas
• Freis Amanda Kay
• Grima Anthony J
• Huff Garret Sankey

Classifications

• F16B5/02

  by means of fastening members using screw-thread ({F16B5/0004 takes precedence}; construction of screw-threaded connections F16B25/00 - F16B39/00) · CPC title

• B21J5/066 Primary

  Flow drilling · CPC title

• F16B25/0031

  the screw being designed to be screwed into different materials, e.g. a layered structure or through metallic and wooden parts · CPC title

• F16B25/106

  by means of a self-piercing screw-point, i.e. without removing material · CPC title

• F16B25/0084

  characterised by geometric details of the tip · CPC title