CN1041287C - Improved plate riveting method - Google Patents

Abstract

In a clinched joint to secure panels together, a rivet or slug is driven into the clinched joint as it is formed, and the inner end of the rivet or slug is outwardly-deformed to increase both the shear and axial separation load strengths of the clinched joint . Rings or components , which may form parts of sub-assemblies, may also be secured to the pannels by the clinching methods, the rings or components acting as the dies for the joints .

Description

Improved plate riveting method

The present invention relates to a sheet riveting method for riveting at least two sheets together by using a rivet, a punch, and a pre-tightening head. The term "riveting" is also called "stamping connection" or "integral fastening ".

In the automotive industry, spot welding is the most commonly used technique for joining car body parts, but the strength of the individual welds cannot be guaranteed due to, for example, the presence of impurities between the parts, or poor weld penetration, and designers It is necessary to increase the number of solder joints to ensure sufficient connection strength.

Spot welding has not been developed as an accurate and reliable method for joining components of galvanized steel or aluminum.

In the case of galvanized steel, the welding action destroys the zinc coating around the weld, making it susceptible to corrosion.

Aluminum has great potential in the automotive sector due to its low weight, but the lack of suitable spot welding methods is one reason that limits its application.

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

Another alternative is metal riveting, in which a punch and die combination is used to deform two metal sheets into a locking joint, examples of metal riveting methods are disclosed in:

1. DE 4009813 (Fraunhoffer-Ges Ford Ange);

2. DE 1452820 (Philips Patentverwaltung GmbH);

3. DE 3726392 (Kuka Schweissanlage);

4. EP 330061 (Eckold W. & Co GmbH);

5. EP 215449 (Rapp E.);

6. GB 2244946 (Fairacre Limited);

7. GB 2123734 (BTM Corporation);

8. US 3919955 (Du Vernay);

9. US 387599 (Ladouceur et al);

The methods described above can join metal sheets together, but they have low shear strength and axial load strength, and the joint does not have an outer surface roughly flush with the surrounding metal sheets (so not suitable for exposed parts, e.g., in in the engine compartment).

Still other documents disclose various ways of riveting panels. Some need to punch holes on the plate first and then use the corresponding rivets for riveting. It goes without saying that this riveting method has at least two processes-drilling or punching and riveting, and the production efficiency cannot be high. Some need to use high-strength rivets to punch holes in the plates for riveting, or use high-strength rivets to penetrate into the plates to be connected for riveting, but such high-strength rivets must be Due to the need to make use of its strength, it is made of materials different from the plates to be connected. On the one hand, there is a risk of electrochemical corrosion after riveting, and on the other hand, it also increases the force to deform the rivet to achieve riveting.

Therefore, the object of the present invention is to provide a plate riveting that overcomes the shortcomings of the prior art, requires simple equipment and is easy to operate, and can improve the shear strength and axial separation strength of the riveted joint. method.

The object of the present invention is achieved by the technical solution of riveting sheets together using a tubular rivet, a punch, a punch peripheral sleeve, and a pretensioning head. The method includes the following steps:

The sheets to be joined are pre-compressed with the pre-tensioning head on a support die formed with a grip to accommodate the sheets when the sheets are deformed, before the punch drives the rivets into the sheets to form the riveted joint. opening;

Position the rivet over the area of the sheet to be riveted, with the sleeve surrounding the punch;

feeding the punch and sleeve downwardly to deform the sheet of material into the opening of the support die without penetrating to form a clinched connection; and

The sleeve of the punch is then independently fed to deform the inner end of the rivet body outwards, thereby deforming the sheet forming that part of the riveted joint, the rivet and the sheet deforming without the rivet penetrating sheet.

The term 'outwardly deformed' as used herein includes deformation of all or part of the body or shank of the rivet or pellet in at least one direction transverse to the longitudinal axis of the body or shank.

In the above technical solution, the first step of feeding is to feed the punch and the rivet downward at the same time so that the plate enters the opening of the support mold, and as the sleeve is further fed downward, the inner end of the rivet is Outer deformation to achieve a riveted connection with high strength.

Another technical solution of the present invention is that the method utilizes a core block with a core body with a semi-tubular inner end, a punch, and a pre-tightening head on the periphery of the punch to rivet the plates together. The method includes the following steps:

The sheets to be joined are pre-compressed with said pre-tensioning head against a supporting punch on which a Openings to accommodate deformed sheets;

feeding the punch down to deform the sheet material into the opening of the support die without penetrating to form the riveted joint, followed by raising the punch;

placing the pellet over the riveted joint and aligning it with said punch;

feeding the punch again to drive the pellet into the clinched joint, and continuing to feed the punch to deform the inner end of the core of the pellet outward so that the clinched joint is formed That part of the sheet at the bottom is deformed without the cores penetrating the sheet.

The method described above is clearly a two-step process. The depression is made first, and then the core block is driven in and the inner end of the core block is deformed outward, so as to obtain a riveted joint with high strength.

The present invention also discloses a matching scheme of a punch with a shoulder and a tubular rivet with an inner tapered end at the inner end, and a punch with a flat end and a solid core block with an arched recess at the inner end. Compatible program. In general, it is one process and two steps of feeding to deform the inner end of the rivet or core block outward to form a riveted joint with high strength.

An advantageous development of the invention consists in that at least one sheet metal is a metal sheet and at least one sheet metal is a polymer sheet which is preheated in the region of the riveted joint to facilitate flow of the polymer material during deformation of the sheet metal.

While the invention is particularly applicable to joining metal sheets, it is also applicable to polymeric materials (eg polyethylene, polyurethane, polypropylene, nylon) where one or more of the metal sheets may be replaced by a sheet of polymeric material. For example, where the method is suitable for joining an aluminum sheet to a polypropylene sheet, the polymeric sheet may be locally preheated (for example by supporting the die) to promote the "flow" of the polymeric material as the joint is formed.

Another structural development of the invention consists in the application of an adhesive on the rivet to assist the bond between the sheet and the rivet or core. Where the rivet is tubular, adhesive may be applied into the bore of the tubular rivet to force the adhesive into the riveted joint as the tubular rivet deforms to enhance the bond between the sheet and rivet.

Yet another structural development of the invention consists in that the rivet or slug has at least one external projection on its stem to provide additional engagement between the rivet or slug and the sheet metal within the riveted connection.

The internal bore of the rivet or core can be threaded, serrated or otherwise configured to engage and support a fastener for, for example, a wiring ring support, a trim cover fastener or the like. Can be attached to the rivet or core with a plastic insert to provide a flush exterior surface.

The present invention will be described in detail with reference to the accompanying drawings. In the attached picture,

Figure 1 is a side sectional view of a hollow rivet or tubular core suitable for riveting two metal plates together;

2 to 5 are side cross-sectional views of each step in the two-step process of forming a riveted connection according to the first embodiment;

Fig. 6 is a side sectional view of the riveted connection part of the first embodiment;

Fig. 7 is a side sectional view of a modified tubular rivet or slug;

8 to 11 are side cross-sectional views of the steps of the single-step process of forming the riveted connection of the second embodiment;

Fig. 12 is a side sectional view of the riveted connection part of the second embodiment;

Figure 13 is a side sectional view of a solid rivet or core block;

14 and 15 are side sectional views of steps of forming a riveted connection in the third embodiment;

Fig. 16 is a side sectional view of the riveted connection part of the third embodiment;

Figure 17 is a side sectional view of a half-tubular rivet or core;

18 to 22 are side sectional views of the steps of forming the riveted connection of the fourth embodiment;

Fig. 23 is a side sectional view of the riveted connection part of the fourth embodiment;

Figure 24 is (a) top view, (b) side sectional view, and (c) bottom view of a ring;

Fig. 25 is a cross-sectional view of the riveted connection part of the fifth embodiment;

Figure 26 is a similar view of a modification of the riveted connection of Figure 25;

Figure 27 is (a) top view, (b) side sectional view, and (c) bottom view of one element;

Fig. 28 is a side sectional view of the riveted connection part of the sixth embodiment;

Figure 29 is a similar view of a modification of the riveted connection of Figure 28;

Figure 30 is (a) top view, (b) side sectional view, and (c) bottom view of a second member;

Fig. 31 is a side sectional view of the riveted connection part of the seventh embodiment;

Fig. 32 is a side sectional view showing the clinched connection of Fig. 31 with the element supported on the die.

Referring now to FIGS. 1-6 , the tubular rivet 10 of FIG. 1 is driven into the sheet metal to form the clinched connection of FIG. 6 .

The metal sheets 12, 13 to be joined together are supported on a die assembly 14 of a riveting tool, which has an expandable and retractable collet 16 which engages a collet seat 17 and an anvil. 18, arranged so that the connecting portion 11 can be released after forming.

The riveting tool 15 has a pre-tensioning head 19 for pressing the sheet metal 12, 13 against the die assembly and a (spring loaded) inner ball 19A for positioning and centering the rivet 10. A punch 20 is slidably mounted in a sleeve 21, and the sleeve 21 is slidably mounted in a tensioning head 19, and the punch 20 and sleeve 21 are connected to respective hydraulic cylinders (not shown).

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

After the tensioning head 19 has pressed the metal plates 12 , 13 against the die assembly 14 , the punch 20 is driven through the rivet 10 to engage the upper plate 12 ; the sleeve 21 engages the rivet 10 . The punch 20 and rivet 10 are advanced, deforming the metal sheets 12, 13 into the die assembly 14 (see Figure 4). The sleeve 21 is then pushed in to deform the inner end of the rivet 10 outward (see Figures 5 and 6).

The anvil 18 may be spring loaded or forced up against the punch 20 as a post-forming operation to assist in the deformation of the rivet or core.

The insertion and deformation of the rivets assist in locking the metal sheets 12, 13 together, increasing their shear strength and axial separation strength (ie in the direction of arrows A and B, respectively).

The hole 22 of the rivet 10 can be threaded to receive a fastener or plug to support, for example, a wire routing ring, or to accommodate a plastic insert to form a flush cover for the riveted connection 11 .

Referring now to FIGS. 7-12, a modified tubular rivet 110 has a tapered end 123 up to an inner bore 122 thereof.

In this one-step process, sleeve 21 is omitted, punch 120 is slidably received in preload head 119, and metal plates 112, 113 are supported on die assembly 114 and compressed by preload head 119. The punch 120 engages the rivet 110 (see FIG. 9 ) and drives the rivet 110 into the metal sheets 112 , 113 which are deformed into the die assembly 114 (see FIG. 10 ). Further pushing the punch 120 (see FIG. 11 ) deforms the inner end of the rivet 110 to form the riveted connection portion 111 (see FIG. 12 ).

In order to increase the strength of the riveted joint 11, 111, a solid or semi-tubular rivet or core can be used.

Referring now to FIGS. 13-16 , a solid core block 210 (see FIG. 13 ) has an arcuate recess 222 at its lower end for forming the riveted connection 211 of FIG. 16 .

The pretensioner 219 compresses the metal sheets 212, 213 against the die assembly 214 (see FIG. 14). Advancing the punch 220 drives the pellet 210 (as an extension of the punch 220 ) into the metal sheets 212 , 213 , deforming the sheets into the die assembly 214 to form the clinched connection 211 . It should be noted that the head of the core block 210 is flush with the outer surface of the plate 212. This connection is suitable where aesthetics are required, such as on the visible surface of the vehicle body.

The semi-tubular pellet 310 (see FIG. 17 ) has a tapered end 323 up to its inner bore 322 .

In the two-step process shown in Figures 18 to 23, the tensioning head 319 pre-compresses the metal plates 312, 313 on the die assembly 314, and advances the punch 320 (see Figure 19) to form a conventional button Button-type riveted connection part 311A (see FIG. 20 ). The punch 320 is retracted and a half-tubular core 310 is placed into the riveting tool.

The pre-tightening head 319 presses the plate (see FIG. 21 ), and pushes the punch 320 to drive the core block 310 into the riveted connection portion 311A to deform the core block 310 to form the riveted connection portion 311 (see FIG. 23 ).

Referring now to Fig. 24 and Fig. 25, rivet or slug (10, 110, 210, 310) can be replaced by a metal or plastic ring 410, and this ring engages with lower plate 413 and locks riveted joint 411, The sheets 412 , 413 are deformed into the flared tapered bore 422 of the ring 410 . The ring 410 is supported by a die assembly (not shown) as the punch (not shown) deforms the sheets 412, 413, the ring 410 acting as a die body.

As shown in FIG. 26, a strap or clip 424 may be integrally formed with ring 410 to secure wiring to the vehicle body, for example. If desired, the ring 410 can be combined with the method shown in FIGS. s surface.

It is also possible to use an element 510 (see Figures 27 to 29) which has a tapered recess or hole 522, and a threaded hole 525 (as part of an auxiliary assembly not shown), the element 510 can be used as a riveting The stamping of the connection part 511 and provides a seat for the auxiliary components fixed on the plates 512,513.

As shown in FIG. 29 , a solid core block 210 can be pressed into the riveted joint 511 . (The core block 210 can be threaded and has a groove, a cross-head groove or a hexagonal groove, so that the core block 210 can be removed when the connection part 511 needs to be disassembled).

Figures 30 to 32 show the connection of a second element 610 having a hole 622 and a smooth head (Figure 30) or a threaded head 626 (Figure 31), the second element 610 being fixed to the riveted connection . (The shape of the bolt head can also be engaged with, for example, a catch or locking device).

Figure 32 shows element 610 being supported by a die assembly 614 during the riveting step.

In the method shown in Figures 24 to 26, Figures 27 to 29 and Figures 30 to 32, two plates 412, 413, 512, 513, 612, 613 secured to ring 410 and elements 510, 610 are shown. This method can also be used to secure a veneer to the ring 410 or elements 510,610.

Furthermore, in all methods one or both plates may be polymeric (e.g. polypropylene), preferably the inner plate (e.g. 13, 113) is polymeric, and the die assembly may be heated at the location of the riveted joint to Promotes "flow" of polymeric material.

To improve recyclability, it is preferred that the rivets 10, 110, cores 210, 310, rings 410, or elements 510, 610 be of the same type of material as the plates, since this eliminates the need to dismantle the connection.

As an indication of the advantages of the method of the present invention, the use of 8 mm solid rivets or pellets in combination with riveted joints can increase the shear strength of the metal plate joint by 50%, as opposed to spot welding, and the shear strength and axial The strength of the separation direction can be kept within the controlled limit. This means that the number of riveted connections can be much smaller than spot welds, and these connections can also support auxiliary components.

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

Claims (8)

1. A sheet riveting method that utilizes a tubular rivet, a punch, a punch peripheral sleeve, and a pre-tightening head to rivet at least two sheets together, the method comprising the following steps: The sheets to be joined are pre-compressed with said pre-tensioning head on a supporting die formed with a grip to accommodate the sheets when the sheets are deformed, before the punch drives the rivets into the sheets to form the riveted joint. opening; Position the rivet over the area of the sheet to be riveted, with the sleeve surrounding the punch; feeding the punch and sleeve downwardly to deform the sheet of material into the opening of the support die without penetrating to form a clinched connection; and The sleeve of the punch is then independently fed to deform the inner end of the rivet body outwards, thereby deforming the sheet forming that part of the riveted joint, the rivet and the sheet deforming without the rivet penetrating sheet. 2. The method of riveting sheets according to claim 1, characterized in that at least one sheet is a metal sheet and at least one sheet is a polymeric sheet which is preheated in the area of the riveted joint to facilitate deformation of the sheets Flow of polymeric materials. 3. The sheet riveting method according to claim 1, characterized in that an adhesive is applied on the rivet to assist the bonding between the sheet and the rivet. 4. The sheet riveting method as claimed in claim 3, wherein the adhesive is applied to the inner hole of the tubular rivet, and when the tubular rivet is deformed, the adhesive is squeezed into the riveted joint to assist the sheet and The bond between the rivets. 5. A method of riveting sheets of material as claimed in claim 1, wherein the rivet has a rivet body with at least one external protrusion for providing additional engagement between the rivet and the sheet within the riveted joint . 6. A sheet riveting method for riveting at least two sheets together by utilizing a core block with a core with a semi-tubular inner end, a punch, and a pre-tightening head on the periphery of the punch, the method comprising The following steps: The sheets to be joined are pre-compressed with said pre-tensioning head against a supporting die on which a Openings to accommodate deformed panels; feeding the punch down to deform the sheet material into the opening of the support die without penetrating to form the riveted joint, followed by raising the punch; placing the pellet over the riveted joint and aligning it with said punch; feeding the punch again to drive the pellet into the clinched joint, and continuing to feed the punch to deform the inner end of the core of the pellet outward so that the clinched joint is formed That part of the sheet at the bottom is deformed without the cores penetrating the sheet. 7. The method of riveting sheets of claim 6, wherein at least one of the sheets is a metal sheet and at least one of the sheets is a polymeric sheet that is preheated in the area of the riveted joint to facilitate deformation of the sheets. Flow of polymeric materials. 8. The sheet riveting method according to claim 6, characterized in that an adhesive is applied on the core to assist the bonding between the sheet and the core.

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