Method for blind rivet welding
A blind rivet assembly is inserted through aligned holes provided in a top member and bottom member. The blind rivet includes a rivet head that abuts the top member and a hollow rivet shank integral with the rivet head. A mandrel includes a mandrel stem that extends thorough the hollow rivet and a mandrel head that abuts the terminal end of the rivet shank. A tool holds the rivet head in contact with the top member and forcibly withdraws the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head of axially collapse and radially expand the terminal end of the rivet shank into engagement with the bottom member to thereby attach the top member and the bottom member together. Weld current is then applied to the rivet head to thereby weld the blind rivet in place.
The present invention relates to an improved method for blind riveting together a pair of members.
BACKGROUND OF THE INVENTIONIt is known to attach together a pair of members using a blind rivet assembly. The use of a blind rivet to attach members together is particularly useful in the assembly or repair of vehicle bodies or other applications in which access can be obtained to only one side of one of the members (a top member), with the other member (a bottom member) being hidden and inaccessible below the top member.
It would be desirable to provide improvements in the blind rivet method of attaching members together. For example, improvements to make such attachments stronger and more vibration proof would be desirable.
SUMMARY OF THE INVENTIONIn an improved method of blind rivet fastening aligned holes are provided in the top and bottom members. A blind rivet assembly is inserted through the aligned holes. The blind rivet includes a rivet head that abuts the top member and a hollow rivet shank that is integral with the rivet head and reaches through and beyond the aligned holes and has a terminal end. The blind rivet assembly also includes a mandrel, the mandrel having a mandrel stem that extends thorough the hollow rivet and includes a mandrel head that abuts the terminal end of the rivet shank. A tool holds the rivet head in contact with the top member and forcibly withdraws the mandrel to thereby cause the mandrel head to axially collapse and radially expand the terminal end of the rivet shank into engagement with the bottom member to thereby attach the top member and the bottom member together. Weld current is then applied to the rivet head to thereby weld the blind rivet in place.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
and
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A hole 14 is drilled, pierced, or otherwise provided through the top member 10 and an aligned hole 16 is provided in the bottom member 12.
A blind rivet assembly 18 is inserted through the aligned holes 14 and 16. The blind rivet assembly 18 includes a blind rivet 22 and a mandrel 24.
The blind rivet 22 has a rivet head 26 and a hollow rivet shank 28 that are integrally formed in one piece. The rivet head 26 rests on the top face 30 of the top member 10. The hollow rivet shank 28 extends through the aligned holes 14 and 16 and is somewhat longer than the combined thickness of the top and member members 10 and 12 and has terminal end 32 that ends somewhat beyond the bottom face 34 of the bottom member 12.
The mandrel 24 includes a stem 38 that extends through the blind rivet 22 and has an enlarged mandrel head 40 at its terminal end. As seen in
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In
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The anvil 50 and the electrode 74 may be a copper material in order to promote the welding process. A person of ordinary skill in the art will recognize that the extent and quality of the weld will be determined by control of the customary welding variables such as the relative thickness and materials of the top and bottom member 10, the size and materials of the blind rivet assembly 18, the distance between the electrodes, the weld current, the duration of the weld current, and the forces with which the electrodes are held against the rivet head 26 and the top member 10 of the weld. Accordingly, in some cases, the weld current may develop material melting and metallurgical bonding between the mandrel 24 and the rivet 22, as well as melting and bonding between the rivet and the top and bottom members 10 and 12.
The forgoing description of the invention is merely exemplary in nature and, thus, variations thereof are intended to be within the scope of the invention. For example, the fracture of the mandrel, as shown in
Claims
1. A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of:
- inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,
- forcibly withdrawing the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member;
- and applying weld current to the rivet head to weld the blind rivet in place.
2. The method of claim 1 comprising the further step of fracturing the mandrel stem from the mandrel head after the mandrel head has axially collapsed and radially expanded the hollow shank of the blind rivet
3. The method of claim 2 further comprising the step of fracturing the mandrel stem after applying the weld current.
4. The method of claim 2 further comprising the step of fracturing the mandrel stem prior to applying the weld current.
5. The method of claim 2 further comprising the step of fracturing the mandrel stem during the application of weld current.
6. The method of claim 1 in which an installation tool for installing the blind rivet assembly includes an anvil that seats on the rivet head and has a welder cable connected thereto so that the anvil functions as an electrode to apply weld current to the rivet head.
7. The method of claim 6 in which the installation tool includes an electrode that is connected to a welder cable and seats against the top member at a distance from the blind rivet so that weld current is conducted through the blind rivet and through the top member.
8. A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of:
- inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,
- applying an installation tool including an anvil seated on the rivet head and jaws for gripping and forcibly withdrawing the mandrel to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member;
- applying an electrode to one of the top and bottom members at a distance from the blind rivet,
- and conducting weld current between the anvil and electrode so that the blind rivet is melted and metallurgically bonded with at least the top member to thereby weld the blind rivet in place.
9. The method of claim 8 in which the blind rivet is welded to both the top member and the bottom member.
10. The method of claim 8 in which the mandrel is welded to the blind rivet.
11. The method of claim 8 in which the electrode is a part of the installation tool so that upon the application of the installation tool to seat the anvil upon the rivet head, the electrode is simultaneously placed against the top member.
12. The method of claim 8 in which at least a portion the mandrel stem is fractured from the mandrel head.
13. A method of blind riveting together a top member and a bottom member provided with aligned rivet holes therein, comprising the steps of:
- inserting a blind rivet assembly through the aligned rivet holes of the top and bottom members, said blind rivet assembly including a blind rivet and a mandrel, the blind rivet having a rivet head abutting the top member and a hollow shank reaching through the aligned holes of the top and bottom members and having a terminal end, the mandrel including a stem extending through the hollow shank of the rivet and a mandrel head adjacent the terminal end of the rivet shank,
- applying an installation tool including an anvil seated on the rivet head and jaws for gripping and forcibly withdrawing the mandrel in the direction to exit the aligned holes to thereby cause the mandrel head to axially collapse and radially expand the hollow shank of the blind rivet into engagement with the bottom member to thereby attach the top member and the bottom member, said installation tool further including an electrode that seats against the upper member at a distance from the rivet head;
- and conducting weld current between the anvil and electrode so that the blind rivet is melted and metallurgically bonded with the top member and the bottom member so that the weld assists the blind rivet in attaching the top and bottom members together.
14. The method of claim 13 in which the installation tool also causes a fracture of at least a portion of the mandrel stem from the mandrel head.
15. The method claim 14 in which the fracture of the mandrel stem occurs one of either before, during or after the application of the weld current.
16. The method of claim 13 in which the weld current causes the mandrel head to become welded to the blind rivet.
17. The method of claim 13 in which the weld current causes the rivet shank to become welded to at least one of the first member and second member.
18. The method of claim 13 in which the weld current welds the rivet shank to the first member and the second member.
19. The method of claim 13 in which the anvil of the installation tool is constructed of a copper-based alloy.
Type: Application
Filed: Aug 30, 2005
Publication Date: Mar 1, 2007
Inventors: Robin Stevenson (Bloomfield, MI), Pei-Chung Wang (Troy, MI)
Application Number: 11/215,197
International Classification: B21D 39/00 (20060101);