AU670418B2

AU670418B2 - Improved panel clinching methods

Info

Publication number: AU670418B2
Application number: AU29367/92A
Authority: AU
Inventors: Stuart Edmund Blacket; Ralph Fuhrmeister
Original assignee: Henrob Ltd
Current assignee: Atlas Copco IAS UK Ltd
Priority date: 1991-11-27
Filing date: 1992-11-25
Publication date: 1996-07-18
Anticipated expiration: 2012-11-25
Also published as: AU2936792A

Description

OPI DATE 28/06/93 AOJP DATE 02/09/93 APPLN. ID 29367/92 I1 II l 1 1 PCT NUMBER PCT/AU92/00631 IllII I 1II 1II II II i111 AU9229367 (51) International Patent Classification 5 (11) International Publication Number: WO 93/10925 B21J 15/04, B21D 39/03 Al B23P 11/00 (43) International Publication Date: 10 June 1993 (10.06.93) (21) International Application Number: PCT/AU92/00631 (81) Designated States: AT, AU, BB, BG, BR, CA, CH, CS, DE, DK, ES, FI, GB, HU, JP, KP, KR, LK, LU, MG, (22) International Filing Date: 25 November 1992 (25.11.92) MN, MW, NL, NO, PL, RO, RU, SD, SE, US, European patent (AT, BE, CH, DE, DK, ES, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE), OAPI patent (BF, BJ, CF, Priority data: CG, CI, CM, GA, GN, ML, MR, SN, TD, TG).

PK 9742 27 November 1991 (27.11.91) AU Published (71) Applicant (for all designated States except US): HENROB With international search report.

LTD [GB/GB]; Unit 12, Aber Park, Flint, Clwyd CH6

(GB).

(72) Inventors; and Inventors/Applicants (for US only) BLACKET, Stuart, Ed- 8 mund [AU/AU]; 18 Beaufort Street, Alderley, QLD 4051 FUHRMEISTER, Ralph [AU/AU]; 14 Jandowae Street, Runcorn, QLD 4113 (AU).

(74) Agent: GRANT ADAMS COMPANY; 9th Floor, National Mutual Centre, 144 Edward Street, (GPO BOX 1413), Brisbane, QLD 4000 (AU).

(54) Title: IMPROVED PANEL CLINCHING METHODS

B

A

22 (57) Abstract In a clinched joint (1 to secure panels (12, 13) together, a rivet or slug (10) is driven into the clinched joint I) as it is formed, and the inner end of the rivet or slug (10) is outwardly-deformed to increase both the shear and axial separation load strengths of the clinched joint Rings (410) or components (510. 610), which may form parts of sub-assemblies, may also be secured to the pannels (412, 413; 512, 513; 612, 613) by the clinching methods, the rings (410) or components (510, 610) acting as the dies for the joints (411, 511, 611).

RECEIVED 1 FE 1 Title: "IMPROVED PANEL CLINCHING METHODS" BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to improved panel clinching methods. The term "clinching" is also known as "press joining" or "integral fastening".

2. Prior Art Spot welding is the most commonly used technique for joining vehicle body components in the automotive industries. As the strength of each spot weld cannot be guaranteed, eg. due to the inclusion of rubbish between the components, or poor weld penetration, designers must increase the number of welds to ensure adequate joint strength.

Spot welding has not yet been developed as an accurate, reliable method for joining galvanised steel or aluminium components.

With galvanised steel, .welding action destroys the galvanising about the weld site, making it liable to corrosion.

Aluminium has great potential in the automobile field due to its light weight, but the lack of a suitable spot welding method is one reasoh which has minimised its application.

One alternative to spot welding is the use of self-piercing rivets, and a method of, and apparatus for, the fastening of metal panels with self-piercing rivets is disclosed in US Patent No 4,615,475 (Fuhrmeister) International Publication Number WO 84/04710).

A further alternative method is metal clinching, where two sheets of metal are defogd into a locking engagement using a punch-and-die combination.

Examples'of metal clinching methods are disclosed in: 1. DE.4009813 (Fraunhoffer-Ges Ford Ange); AMENDED SHEET

IPEA/AU

RECEIVED FEB 19 2 2. DE 1452820 (Philips Patentverwaltung GmbH); 3. DE 3726392 (Kuka Schweissanlage); 4. EP 330061 (Eckold W. Co GmbH); 5. EP 215449 (Rapp 6. GB 2244946 (Fairacre Limited); 7. GB 2123734 (BTM Corporation); 8. US 3919955 (Du Vernay); and 9. US 3878599 (Ladouceur et al).

While these methods enable metal sheets to be joined together, they have relatively low shear and axial load strengths, and the joints do not have an outer face substantially flush with the surrounding sheet metal (and are so not applicable in exposed areas, eg. within an engine compartment).

SUMMARY OF THE PRESENT INVENTION It is an object of the present invention to provide a panel clinching method where the shear strengths of the clinching joint is increased.

It is a preferred object to provide a method where the axial load strength of the clinched joint is increased.

It is a further preferred object to provide a method where the outer face of the joint may be substantially flush with the surrounding sheet metal.

It is a still further preferred object to provide a method where ancillary components may be supported by or,from the clinched joint.

It is a still further preferred object to provide a method where the clinched joint may be "capped" to constrain any stress lines in the metal panels in the region of the joint.

Other preferred objects will become apparent from the following description.

In ,one aspect, the present invention resides SAMENDED

SHEBT

RECEIVED 1 4 FEB 1994 in a panel clinching method wherein: a hollow rivet or full tubular slug is driven or inserted into a clinched joint between panels and at least the inner end of the shank of the rivet or slug is outwardly-deformed within the joint; where the rivet or slug does not penetrate the panels.

The term "outwardly-deformed" shall be used to include deformation of all or part of the shank or stem of the rivet or slug in at least one direction lateral (or transverse) to the longitudinal axis of the shank or stem.

In a single stage method, the rivet or slug may be inserted into the joint as the joint is formed, the rivet or slug co-operating with the punch to deform the panels into the supporting dee. In a two-stage process, the rivet or slug co-operates with the punch to deform the metal panels into the die, and a sleeve external to the punch then deforms the rivet or slug within the joint.

The bore of the rivetior slug may be threaded, serrated or otherwise profiled to engage and support an anchor for, eg. a wiring loom support, a tri cover panel fastener or the like. A plastic. insert may be fitted to the rivet or slug to provide a flush outer face. o Preferably, the panels are pre-clamped to. the die before the punch drives the rivet or slug into the panels to form the clinched joint; or before the' clinched joint is formed and the rivet or slug is then inserted into the joint.

In a second aspect, the present invention resides in a panel clinching method where a solid or semi-tubular rivet or slug is driven or inserted into a clinched joint between panels and at least the inner end of the shank of the rivet or slug is outwardly-deformed AMENDED SHEET

IPEA/AU

within the joint, where the rivet or slug does not penetrate the panels.

In a single stage process, the rivet or slug is interposed between the punch and the outer panel (to be joined) and the rivet or slug is used to deform the metal panels into the die as the clinched joint is formed.

In a two-staged process, a conventional button-type clinched joint is formed and then the rivet or slug is pressed into the joint by the punch.

Preferably, the panels are pre-clamped to the die before the clinched joint is formed.

In a third aspect, the present invention resides in a clinched joint for panels formed by the V. 15 method of any one of the first or second aspects.

While the invention is particularly suitable for joining sheet metal panels, it is also suitable for polymeric materials (eg. polyethylene, 2 polyurethane, polypropylene, nylon) where one or more 20 metal panels are substituted by panels of polymeric material. For example, the methods are suitable for joining, eg. an aluminium sheet to a polypropylene :sheet, where the polymeric sheet may be locally :preheated (eg. by the supporting die) to assist in the "flow" of the polymeric material as the joint is :'.".formed.

The shanks of the rivets or slugs may be provided with external splines, grooves, teeth or other protrusions or recesses to provide additional grip between the rivets or slugs and the panels in the clinched joint.

Adhesives can be applied, eg. to the shanks of the rivets or slugs to assist bonding of the rivets or slugs to the panels. Adhesives may also be provided within the bore of the tubular or semitubular rivets or slugs to be extruded into the Sclinched joint, as the rivets or slugs are deformed, to assist the bonding of the rivets or slugs to the panels.

In further aspects, the present invention is directed to apparatus for effecting the methods hereinbefore described.

BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a sectional side view of a hollow rivet or tubular slug suitable for clinching two panels of metal together; FIGS 2 to 5 are sectional side views of the steps in a two-stage process of forming a clinched joint of a first embodiment; FIG 6 is a sectional side view of the clinched joint of the first embodiment; 15 FIG 7 is a sectional side view of a Se. modified tubular rivet or slug; FIGS 8 to 11 are sectional side views of the steps in a single-stage process of forming a clinched joint of a second embodiment; FIG 12 is a sectional side view of the C. C C

C

clinched joint of the second embodiment; FIG 13 is a sectional side view of a solid rivet or slug; FIGS 14 and 15 are sectional side views of the steps of forming a clinched joint of a third embodiment; FIG 16 is a sectional side view of the S S 1 S *oo *o *o* clinched joint of the third embodiment; FIG 17 is a sectional side view of a semitubular rivet or slug; FIGS 18 to 22 are sectional side views of the steps of forming a clinched joint of the fourth embodiment; and FIG 23 is a sectional side view of the clinched joint of the fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED

EMBODIMENTS

Referring now to FIGS 1 to 6, the tubular rivet 10 of FIG 1 is driven into the metal panels to form the clinched joint 11 of FIG 6.

The metal panels 12, 13 to be joined 15 together are supported on the die assembly 14 of a clinching tool(s), the die assembly having expandable and contractable collets 16 associated with a collet holder a oa *o• WO 93/10925 PCT/AU92/00631 7 17 and anvil 18 arranged to allow the joint 11 to be released when formed.

The clinching tool 15 has a pre-clamping head 19 which clamps the metal panels 12, 13 to the die assembly and has internal (spring-loaded) balls 19A to locate and centralise the rivet 10. A punch 20 is slidably journalled in a sleeve 21, slidably journalled in the pre-clamping head 19, and the punch 20 and sleeve 21 are connected to respective hydraulic rams (not shown).

The operation of the clinching tool 15 will now be described.

After the metal panels 12, 13 are clamped to the die assembly 14 by the pre-clamping head 19, the punch 20 is driven through the rivet 10 into engagement with the upper panel 12; the sleeve 21 engaging the rivet 10. The punch 20 and rivet 10 are advanced to deform the metal panels 12, 13 into the die assembly 14 (see FIG The sleeve 21 is then advanced to cause the inner end of the rivet 10 to be outwardly-deformed (see FIGS 5 and 6).

The anvil 18 can be spring-loaded or forcibly raised as a post-forming operation against the punch to assist in deforming the rivet or slug.

The insertion and deformation of the rivet assists in locking the metal panels 12, 13 together, with increase in the shear and axial separation strength(s) (ie. in the direction of arrows A and B, respectively).

The bore 22 of the rivet 10 may be threaded to receive a fastener or plug to support, eg. an electrical wiring loom or a plastic insert to form a flush cover for the clinched joint 11.

Referring now to FIGS 7 to 12, a modified tubular rivet 110 has a tapered end 123 to its inner WO 93/10925 PCT/AU92/0631 8 bore 122.

In this one-stage method, the sleeve 21 is eliminated and the punch 120 is slidably journalled in the pre-clamping head 119. The metal sheets 112, 113 are supported by the die assembly 114 and clamped thereto by the clamping head 119. The punch 120 engages the! rivet 110 (see FIG 9) and drives the rivet 110 into the metal panels 112, 113 which are deformed into the die assembly 114 (see FIG 10). The punch 120 is further advanced (see FIG 11) to deform the inner end of the rivet 110 to form the clinched joint 111 (see FIG 12).

To increase the strength of the clinched joints 11, 111, a solid or semi-tubular rivet or slug may be used.

Referring now to FIGS 13 to 16, a solid slug 210 (FIG 13) has a concave recess 222 at its lower end and is used to form the clinched joint 211 of FIG 16.

The metal sheets 212, 213 are clamped to the die assenmbly 214 by the clamping head 219 (see FIG 14).

The punch 220 is advanced to drive the slug 210 (as an extension of the punch 220) into the metal panels 212, 213 to deform the panels into the die assembly 214 to form the clinched joint 211. It will be noted that the head of the slug 210 is flush with the outer face of panel 212 and such a joint is suitable where aesthetic appeal is required, eg. on a visible surface of a vehicle body.

The semi-t,' ular slug 310 (see FIG 17) has a tapered end 323 to its bore 322.

In the two-stage process shown in FIGS 18 to 23, the metal panels 312, 313 are pre-clamped to the die assembly 314 by the clamping head 319 and the punch 320 is advanced (see FIG 19) to form a conventional buttontype clinched joint 311A (see FIG 20). The punch 320 is retracted and a semi-tubular slug 310 is placed in the clinching tool.

The pre-clamping head 319 clamps the panels (see FIG 21) and the punch 320 is advanced to drive the slug 310 into the clinched joint 311A to deform the slug 310 to form the clinched joint 311 (see FIG 23).

In all of the methods, one or both panels may be a polymeric sheet (eg. polypropylene), it being preferred that the inner sheet, (eg. 13, 113) being the polymeric sheet and the die assembly may be heated at the location of the clinched joint to assist "flow" of the polymeric a.c rial.

For improved recycling, it is preferred that the rivets 10,110; or slugs 210, 310; be of the same type of material as the panels as this will obviate the need for disassembly of the joints.

As an indication of the advantage of methods of the present invention, the use of an 8mm solid rivet or slug in conjunction with a clinched joint increase the shear strength of a sheet metal joint by 50% and the strength to both the shear and axial separation directions can be maintained within controlled limits, unlike spot welds. This means the number of clinched joints can be much less than the number of spot welds, and the joints can also support sub-assemblies.

Various changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention defined in the appended claims.

Claims

1. A panel clinching method wherein: a hollow rivet or tubular slug is driven or inserted into a clinched joint between panels and at least the inner end of the shank of the rivet or slug is outwardly-deformed within the clinched joint, where the rivet-'rslug does not penetrate the panels.

2. A method according to Claim 1 wherein: the rivet or slug is inserted into the clinched joint as the clinched joint is formed, the rivet or slug co-operating with a punch to deform the panels being joined into a supporting die.

3. A method according to Claim 1 wherein: the rivet or slug co-operates with a punch to deform the panels being joined into a supporting die, and a sleeve external to the punch is advanced relative to the punch to deform the rivet or slug within the clinched joint.

4. A method according to any one of Claims 1 to 3 wherein: the panels to be joined are pre-clamped to the die before the punch drives the rivet or slug into the panels to form the clinched j'oint.

An apparatus for effecting the method of claim 2 or Claim 4 including: a die to support the panels to be joined; and a punch having a nose receivable in a bore through the rivet or slug; so arranged that the nose of the punch enters the bore and the punch is advanced so that the rivet or slug and the nose of the punch deform the panels into the clinched joint in the die; and to outwardly-deform at least the inner end of the shank of the rivet or slug in the clinched joint, where the rivet g [IP5A/SUBSTITUTE SHEET I I I I V I 'RECEIVED P F 11 or slug does not penetrate the panels.

6. An apparatus for effecting the method of Claims 3 or 4 including: a die to support the panels to be joined; a punch having a nose receivable in a bore through the rivet or slug; and a sleeve external to the punch; so arranged that the nose of the punch enters the bore and the punch is advanced so that the rivet or slug and the nose of the punch deform the panels into a clinched joint in the die; and the sleeve is then advanced to outwardly- deform at least the inner end of the shank of the rivet or slug in the clinched joint, where the rivet or slug does not penetrate the panels.

7. An apparatus according to Claim 5 or Claim 6 and further including: a pre-clamping head to clamp the panels to the die before the punch, and rivet or slug, is advanced.

8. A clinched joint between two panels formed by the method of any one of Claims 1 to 4. j

9. A panel clinching method wherein: a solid or semi-tubular rivet or slug is driven or inserted into a clinched joint between panels and at least the inner end of the shank of the rivet or slug is outwardly-deformed within the clincheq jpint, where the rivet or slug does .not penetrate the panels.

A method according to Claim 9 wherein: the rivet or slug is interposed between a punch and the outer of the panels to be joined, and the rivet or slug deform the panels into a die as the punch is advanced and the cl-inched joint is formed, the punch being further advanced to deform at least the inner end of the shank of the rivet or slug within the clinched AMENDED SHEET IPEA/AU joint, where the rivet or slug does not penetrate the panels.

11. A method according to Claim 9 wherein: a punch forms a conventional button-type clinched joint in the panels to be joined, the panels being supported by a die; and the rivet or slug is interposed between the punch and the clinched joint; and the punch is advanced to drive the rivet or slug into the clinched joint and then further advanced to deform at least the inner end of the shank of the rivet or slug in the clinched joint.

12. A method according to Claim 10 or Claim 11 wherein: 15 the panels to be joined are pre-clamped to the die before the punch drives the rivet or slug into the panels to form the clinched joint.

13. An apparatus for effecting the method of any one of Claims 9 to 12 including: 20 a die to support the panels to be joined; and a punch to drive the rivet or slug, or the panels, into the die to deform the panels to form the clinched joint, and to deform at least the inner end of the shank of the rivet or slug in the clinched joint, where the rivet or slug does not penetrate the panels.

14. An apparatus according to Claim 13 and further including: a pre-clamping head to clamp the panels to the die before the punch, or rivet or slug, are advanced.

A clinched joint between two panels formed by the method of any one of Claims 9 to )2.

16. A panel clinching method as claimed in any one of Claims 1 to 4; or Claims 9 to 12 wherein: at least one panel is a metal sheet ar' at least one panel is a polymeric sheet, the polymeric sheet being pre-heated in the zone of the clinched joint to encourage the "flow" of the polymeric material as the panels are deformed.

17. A panel clinching method as claimed in any one of Claims 1 to 4; or Claims 9 to 12; or Claim 16 wherein: an adhesive is applied to the rivet or slug, to assist bonding between the panels and the rivet or slug.

18. A panel clinching method as claimed in any one 15 of Claims 1 to 4 wherein: an adhesive is applied to the bore of the tubular rivet or slug, the adhesive being extruded into S•the clinched joint when the tubular rivet or slug is deformed to assist bonding between the panels and the 20 rivet or slug.

19. A panel clinching method as claimed in any one 9 of Claims 1 to 4; or Claims 9 to 12; wherein: the rivet or slug has a shank with external splines, grooves, teeth or other protrusions or recesses to provide additional grip between the rivet or slug and the panels in the clinched joint. 0mo