KR20070031461A - Fastening element for being friction welded to a flat component - Google Patents

Abstract

The present invention relates to a fastening element having a face, which face is frictionally welded to the flat member (12, 26) by a rotational force acting on the fastening element and a pressing force toward the flat members (12, 26). A concentric annular bead 3 is provided. The annular bead 3 has concentric lines in contact with the members 12, 26 in the largest projecting area 6 and is part of the flange 4, the flange being an annular bead 3, A concave groove 7 having an outer wall 25 for removing the polished portion generated during the friction welding is provided on the outside of the annular bead 3, and a central concave for receiving the polished portion. By having the part 8, the flange 4 forms on the opposite side of the annular bead 3 an opposite surface 5 for the pressing force towards the members 12, 26, the outside of which is Form a driver for torque on the surface.

Friction welding, fastening elements, annular rings, studs, nuts, radial grooves, recesses

Description

FASTENING ELEMENT FOR BEING FRICTION WELDED TO A FLAT COMPONENT}

The present invention relates to a fastening element having a front face having a concentric annular ring for friction welding to the flat member through the rotational force acting on the fastening element and the pressing force on the flat member.

Such a fastening element is shown in figure g of DE 199 27 369 A1, wherein the fastening element disclosed herein is a stud with a flange at one end, the flange being a concentric annular ring on the opposite side of the stud. Equipped with. The annular ring forms the radial end of the flange and surrounds the central recess. The friction surface of the annular ring is flat, which in turn results in an annular flat friction surface in the stud, the friction surface of which can be attached to the flat member by means of friction welding. Of course, during friction welding operations through rotation of the fastening element and pressing against the member, known studs having a relatively large friction surface cause the heat necessary for partial melting of the contact surfaces. A disadvantage of this, however, is that during the rotation of the fastening element and the pressing against the member, a radial shear force is generated, which, in addition to rotation, also causes the stud to add considerable instability to the friction welding operation. deflection) periodically.

U. S. Patent No. 4,850, 772 also discloses a stud that is attached to the member by friction welding, the front surface of the stud forming a surface coupled to each member by friction welding. The stud has a flange away from the front side, the flange being designed to transmit rotational and compressive forces, the opposite flange portion of the stud front side being slightly conical in shape and radially with ridges on the flange portion. A continuous flute groove having a directivity of is provided. Thus, the above directional flute grooves form the cone with each other, and the directional flute groove receives the rotational force through the flute groove and the compressive force through the radial portion of the flange and the friction of the stud for friction welding. It is received by a chuck of a corresponding shape that transmits the forces through the shank to the front of the stud. In the stud-based friction welding process, it is necessary to apply both considerable rotational and compressive forces, so that a configuration in which flute grooves are formed on the surface of the flange means that a gradient of the individual flute grooves is used. The chuck of the friction welding device is inclined to regularly move away from the flange, and as a result can cause, among other things, rocking motion in the axial direction, which is undesirable for friction welding operations.

It is an object of the present invention to design a fastening element as described above which has a propensity to automatically center itself during rotation by equal guidance. It is an object of the present invention that in the region of the largest elevation of the annular ring, the annular ring has concentric contact lines to the member and is part of the flange, the flange comprising the annular ring, Also included on the outside of the annular ring is a concentric groove having a central indentation to receive the polished material as well as an outer wall for removing the polished material generated during the friction welding operation. On the opposite side of the annular ring of 4) abutting surface for the pressing force against the member is formed, a driver for the rotational force is formed on the outer side of the flange.

Because of this form of an annular projection with concentric contact lines, when the fastening element is rotated and pressed against a flat member, an impression line following the contact line is immediately formed in the member. The impression line is deepened as the friction welding operation progresses and thus automatically provides self-centering of the fastening element during the friction welding operation. In this process, the concentric grooves surrounding the annular ring, together with the outer wall and center indentation of the annular ring, allow the abrasive material, in particular molten residue and dust particles, generated during friction welding to be removed or accommodated. Thus, the polished material is automatically removed from the area that is actually friction welded and thus cannot interfere with the friction welding operation. Since the annular ring is incorporated into the flange, preferably the flange can perform a number of functions, that is to say a transfer of rotational and compressive forces, thus compact design of the fastening element according to the invention. ) Is possible. The flange must act during friction welding and can absorb the necessary compressive force transmitted from the rotating fastening element to the friction welding zone of the member. The flange is used simultaneously as a driver, especially when the flange is in the form of a hexagon, which is preferable for driving the fastening element by the rotating chuck of the corresponding tool, the flange of which is the chuck of the friction welding device on the part opposite the annular ring Forming abutting surface for the chuck, as described above, the chuck transmits the compressive force applied to the flange to the weld site.

Preferably, the annular ring may have a convex cross section. This configuration results in a concentric narrow contact line which automatically brings about the above mentioned centering of the fastening element during the friction welding operation when the annular ring is in contact with the member. In this regard, the convex shape also has a compensating effect when the fastening element is not exactly positioned perpendicularly to the member.

Optionally, however, other cross sectional shapes of the annular ring are possible, such as, for example, by means of convex concentric faces, whereby the annular ring is bounded in the cross section, the conical surface being the outer edge of the annular ring in the outward direction. Ends at the contact line. In this case, the concentric contact lines are arranged as far as possible to the outer edge of the annular ring, which further enhances the centering effect of the contact lines.

Suitably the fastening element can be in the form of a stud or a nut, for example. When the fastening element is in the form of a nut, the fastening element is preferably in the form of a weld with one side having a concentric annular ring for the friction welding operation, and the other side with a contact-making for electrical contact of the electrical conductor. in the form of a ground contact in that the contact forming portion has a concentric projection with respect to the nut body, wherein the front surface of the projection forms a contact forming surface and the rounded outer side of the projection. The edge is covered and sealed at the top by the head of a pre-mounted screw.

For attachment and friction welding of the friction welding nut, the nut is provided with a concentric annular ring, the concentric annular ring bringing concentric contact lines for each member during the friction welding operation, which is subjected to compressive force, Induce self-centering during rotation of the friction welding nut.

The concentric protrusions forming the subsequent contact forming sites are initially covered with a head of a pre-mounted screw during attachment of the friction welding nut by friction welding, and due to the pressing against the protrusions, the head simultaneously forms the contact. To ensure the sealing of the site, as a result of which the contact formation is kept free of contaminants until the friction welding nut is finally attached, and loosen the pre-mounted screw, whereby the electrical conductor is friction welded Screwed into the nut. In this connection, the pre-mounted screw, on the one hand, thus forms a sensitive contact of the friction welding nut during the attachment of the friction welding nut and during the subsequent painting process and also during the fastening of the electrical conductor to the contact formation of the friction welding nut. It serves to cover the part and keep it clean, as a result of which the contact forming part of the friction welding nut is always protected against contamination and corrosion, thereby reliably ensuring contact formation.

Preferably, the concentric protrusions are designed such that the diameter of the outer edge is smaller than the smallest diameter of the underside of the head of the screw. In this case, the screw heads securely cover the top of the projections and consequently the entire surface is always protected against contamination.

In order to ensure particularly good contact formation with simultaneous engagement of the screw and sealing of the contact forming site area, the front face of the protrusion is preferably in the form of a flat concave cone, when the screw head is pressed, the rounded shape of the cone The outer edge forms a linear contact area of increased contact pressure. Because of this form, the electrical conductor, more particularly the cable lug, is pressed particularly firmly against the projection of its rounded outer edge area, which ensures reliable contact formation, i.e. characterized by increased contact pressure. Linear contact areas are formed. The flat concave cone is also a receptacle for the electrical conductor, which ensures that the provided connection is subjected to a self-locking effect, wherein the flat concave region pulls the conductor into the inner region, that is to say, its inner region. Because, it provides protection against loose work. In addition, due to the particularly high pressure at the outer edges of the protrusions there is a remarkably strong sealing effect in its inner direction, which seals the contact forming area against the ingress of moisture and thus provides very efficient protection against corrosion to the thread. There is a desirable effect to provide.

When the fastening element is in the form of a stud with threaded shank, the threaded shank can be used as an area for engaging the stud by the chuck through a transition to the flange, the area being connected to the flange. It forms a connected coaxial cylindrical neck, which is larger in diameter than the threaded shank, transitions to the abutting surface, and as soon as it is engaged by the chuck, allows precisely centered rotation of the studs as well as compression on the members. In addition, it can be easily manufactured in a small error range with respect to its diameter.

During the formation of the friction weld connection, the region inside the annular ring of the molten material is also heated, which can cause evaporation, especially if contaminants or coatings are present. Such vapor is contained by the contact between the member and the annular ring. In order to allow such vapors to be released, the annular ring may have one or more radial grooves, the depth of which corresponds to the friction welding connection. The radial grooves are very narrow, ensuring that the grooves do not cause unwanted excess pressure inside the friction weld connection due to steam, without actually degrading the strength of the friction weld connection. In addition, the radial groove may have the desired effect of removing the coating on the member before the start of the actual friction welding operation.

Exemplary embodiments of the invention are shown in the drawings.

1 shows a side view of a fastening element in the form of a stud with a convex annular ring partially sectioned.

2 is a plan view of the stud seen from the annular ring.

3 shows a stud with a concentric conical surface over a partially sectioned annular ring.

4 shows a fastening element in the form of a stud welded to the member.

5 shows a fastening element in the form of a nut.

6 shows the nut of FIG. 5 welded to the member.

FIG. 7 shows a friction welding nut welded to a metal plate with a pre-mounted screw. FIG.

8 shows the friction welding nut itself.

9 shows a friction welding nut with a screwed-on cable lug.

10 shows a side view of a fastening element in the form of a stud with a convex annular ring partially sectioned.

11 is a plan view of the stud seen from the annular ring.

12 shows the chuck and shows that the studs are joined by the chuck and pressed against the member.

13 shows a stud connected to a member coated by friction welding.

14 is a side view of the fastening element in the form of a stud according to FIG. 1 with radial grooves.

Fig. 15 is a plan view of the fastening element in the form of a stud as viewed from the annular ring, which is provided with three radial grooves.

1 shows a fastening element in the form of a stud 1, which has a smooth shank 2 on one side and an annular ring 3 (cross section) as part of the flange 4 on the other side. Shown). The flange 4 is in the form of a hexagon with respect to its outer surface. For friction welding operations, the stud 1 is clamped into a properly formed chuck of a known friction welding device, for which the hexagon of the flange 4 serves as a preferred driver for receiving the required large torque. During the friction welding operation, the chuck (not shown) is squeezed at the rear surface 5 of the flange 4, as a result of which the annular ring 3 is then flattened with the necessary squeezing force (not shown in FIG. 1). Is pressed). Such a flat member is shown in FIG. When the stud 1 is pressed against the member, the annular ring 3 contacts the maximum protruding region of the annular ring (shown in dashed lines in FIG. 2) 6 and has a very narrow concentric contact line. Is formed, which ensures that during the pressing against the member and during the rotation of the stud 1 it is automatically self-centering of the rotational movement.

2 is a plan view of the stud 1 as seen from the stud portion provided with the annular ring 3. In FIG. 2, as described above, the contact line 6 is indicated by a dashed line 6.

As is evident from FIG. 1, the annular ring 3 is bounded by a concentric groove 7 on one side and bounded by a central indentation 8 on the other side, and an outer wall. 25 forms a surface for removing the polished material using centrifugal force and the recess 8 forms a receiving space for the polished material (molten residue and dust particles). The material can then not interfere with the actual friction welding operation.

3 shows a change in the shape of the stud 1 according to FIG. 1, which shows a cross section of the annular ring identified as 9. The annular ring 9 has a conical surface 10 which is convex in an inward direction, which ends at a concentric contact line 11 in the outward direction. The contact line 11 is arranged away from the outside of the annular ring and in a special way ensures that the stud 1 centers itself during the rotation of the stud.

4 shows the stud 1 in FIG. 1 welded to the flat member 12. The flat member is here formed by a thin coated metal plate, the coating of which is identified by reference numeral 13. As shown, the convex annular ring 13 portion has penetrated into the material of the member 12 and has been welded together with the material of the member 12 in a pore-free manner in that region 14.

FIG. 5 shows a fastening element in the form of a nut 15, on one side which is similar in shape to the stud 1 according to FIG. 1. On the one side, the nut 1 has a convex annular ring 16 and a contact line 17 is formed in the annular ring 16 during the friction welding operation. The groove 18 is provided next to the annular ring 16. In addition, an inner groove 20 is also provided between the annular ring 16 and the through hole 19, which guides any polished material away from the through hole 19.

FIG. 6 shows the nut 15 of FIG. 5 welded to the flat member 26 this time, wherein the flat member is formed by a thin metal plate. As shown, the convex annular ring 16 portion penetrated into the material of the member 26 and was welded with the material of the member 26 in that region 27.

FIG. 7 shows a friction welding nut 31 (see also FIG. 8) welded to the metal plate 38. During the friction welding operation, the friction welding nut 31 is pressed against the metal part 38 in a known manner, and the concentric projection 33 is pressed against each surface of the metal part 38 and heated. And melted, and finally welded together with the metal part 38.

The friction welding nut 31 is provided with a premounted screw 39, the screw head 40 of which is pressed against the outer edge 41 of the cone 36 (shown in FIG. 8), and is wide in width. Because of the narrow, linear contact, a very efficient seal is formed at that site, as a result of which a coating, for example a paint layer, has to be applied with the welded friction welding nut 31, which serves as a contact forming site. It cannot penetrate into the area of the cone 36.

The friction welding nut 31 shown in FIG. 8 includes a nut body 32, one side of which is provided with a concentric annular ring 33 as a welding side. The other side of the friction welding nut 31 forms a contact forming site, which has a concentric projection 34 for this purpose, which is stamped out of the nut body 32. The rounded outer edge of the protrusion 34 has a diameter such that it is covered by the head of a pre-mounted screw 39, which is explained more fully with reference to FIG. 7. The protrusion 34 has a flat, concave cone 36 on its front face, which ensures a remarkably good contact formation and sealing when the electrical conductor is screwed. The cone 36 forms a contact forming site for the screwed conductor (see FIG. 9). The friction welding nut 31 is additionally provided with an internal threaded through hole 37. In addition, the outer surface of the nut body 32 is in the form of a hexagon, so that the friction welding nut 31 can be tightly coupled for friction welding operation by a suitable tool and pressed against the member to be welded.

FIG. 9 shows a friction welding nut 31 welded to the metal part 38, as shown in FIG. 1, with the screw still pre-mounted in the stage shown in FIG. 8 and now friction welding the cable lug 42. Which acts as a screw connection to the nut 31, the cable lug 42 is pressed against the cone 36 more specifically against its edge 41, which results in a particularly secure contact formation and a secure seal. This is because during the crimping, the material of the cable lug 42 is at least partly squeezed into the cone 36, which additionally effectively locks it against the rotation therein.

10 shows a fastening element in the form of a stud 51, the stud 51 having a threaded shank 52 on one side thereof and an annular ring 53 as part of the flange 54 on the other side thereof. (Shown in cross section) is provided. The flange 54 is hexagonal with respect to its outer surface. For friction welding operations, the studs 51 are clamped into a properly formed chuck of the friction welding device (see FIG. 12), for which the hexagon of the flange 54 serves as a preferred driver for receiving the required large torque. do. During the friction welding operation, the chuck (not shown in FIG. 10) compresses at the rear surface 55 of the flange 54, which serves as an abutting surface 55 for the pressing force. The annular ring 53 is then pressed against the flat member (not shown in FIG. 10) with the necessary pressing force. Such flat members are shown in FIGS. 12 and 13. When the stud 51 is pressed against the member, the annular ring 53 contacts the maximum protruding region (shown in dashed line in FIG. 11) 56 of the annular ring, and while pressing against the member. A very narrow concentric contact line is formed which ensures that during the rotation of the stud 51 it is automatically self-centering of the rotational movement.

A neck 60 is provided between the threaded region of the threaded shank 52 and the flange 54, which is cylindrical in shape and extends coaxially with respect to the stud 51, resulting in a neck 60. ) Provides the ideal guidance area for the use of the chuck, thus allowing the studs to be fully pure in the case of a precisely centered rotation. In the form presented, the neck 60 is arranged radially relatively close to the contact line of the maximum protruding region 56, as a result of which it is also preferred for the region with the annular ring 53 necessary for the friction welding operation. Provide induction. The transition from the threaded shank 52 to the neck 60 is formed by a conical gradient 61, which facilitates the use of the chuck.

11 is a plan view of the stud 51 viewed from the stud portion having the annular ring 53. In FIG. 11, contact line 56 is represented by dashed line 56 as described above.

As is apparent from FIG. 10, the annular ring 53 is bounded at one side by a concentric groove 57 and at the other side by a central indentation 58, the outer wall. 75 forms a surface for removing the ground material using centrifugal force and the recess 58 forms a receiving space for the ground material (molten residue and dust particles), the polishing The material can then not interfere with the actual friction welding operation.

FIG. 12 shows a stud 51 which is engaged by the chuck in the stage of rotation of the stud and pressed against the member 62, which is partially shown in FIG. The member 62 is crimped through 69. The chuck includes an annular receptacle 59 that snugly embraces the flange 54 (having a hexagonal appearance) and to a rotating drive (not shown) during friction welding operation. By means of a tubular thrust member 68 coupled with the cylindrical neck 60 centrally in the area, and consequently, during rotation, the coaxial cylindrical neck 60. And the thrust member 68 ensure that the annular ring 53 of the stud rotates completely pure, i.e. without any lateral runout. Due to the rotation and compression of the stud 51 with the annular ring 53, the contact portion of the member 62 and the annular ring 53 is heated to ultimately the region 64 together with the material of the member 62. Friction welding occurs at

FIG. 13 shows the stud 51 in FIG. 10 welded to the flat member 62. Here, the flat member is formed by a thin coated metal plate, the coating of which is identified by reference numeral 63. As shown, the convex annular ring 53 portion penetrated into the material of the member 62 and was welded together with the material of the member 62 in a pore-free manner in the region 64.

FIG. 14 shows the fastening element in FIG. 1, which is further provided with a radial groove 70, which recesses into the annular ring 3 in the maximum projecting area 6. The radial groove 70 only has a small width, the width however roughly corresponds to the extent of the friction welding connection, so that as soon as the friction welding connection is formed, any gas generated in the annular ring 3 It may exit through the groove 70. Because of the small dimensions of the grooves, the radial grooves 70 do not adversely affect the friction welding connection, and the grooves may at least assist the friction welding operation because the contaminants or sheaths of the member are peeled off by the edges thereof. .

15 shows the plane of the same fastening element as seen from the fastening element part with annular ring 3. As shown, three grooves 70, 71, 72 are concave in the annular ring 3. It should be noted, however, that it is also possible to provide more or fewer radial grooves, depending on the materials involved in the friction welding connection required.

Claims (11)

Having a front face having concentric annular rings 3 for friction welding to the flat members 12, 26 through rotational forces acting on the fastening elements and the pressing forces on the flat members 12, 26. Fastening element, In the maximum projecting area 6 of the annular ring, the annular ring 3 has a concentric contact line to the members 12, 26 and is part of the flange 4, The flange 4 comprises the annular ring 3 and an outer wall for removing the abrasive material generated during the friction welding operation as well as a central indentation 8 for receiving the abrasive material. Also included on the outside of the annular ring 3 is a concentric groove 7 having a 25. On the opposite side of the annular ring (3) of the flange (4) is formed abutting surface (5) for the pressing force for the members (12, 26), a driver (driver) for rotational force is formed on the outer side of the flange Fastening element, characterized in that. The method of claim 1, The annular ring (3) is characterized in that it has a convex cross section. The method of claim 1, Annular ring (9) is bounded by a concentric conical surface (10) whose cross section is convex, The conical surface (10) is characterized in that it ends in the outward direction at the contact line of the outer edge (11) of the annular ring (9). The method according to any one of claims 1 to 3, And said driver is in the form of a hexagon. The method according to any one of claims 1 to 4, The fastening element is characterized in that it is in the form of a stud (1). The method according to any one of claims 1 to 4, The fastening element characterized in that it is in the form of a nut (15). The method of claim 6, The fastening element is in the form of ground contact, One side of the ground is in the form of a weld with a concentric annular ring 33 for friction welding operations, the other side being a contact for electrical contact of an electrical conductor with a projection 34 concentric with the nut body 32. In the form of a contact-making side, The front face of the protrusion 34 forms a contact forming surface and the rounded outer edge of the protrusion 34 is covered and sealed by the head 40 of the pre-mounted screw 39. Fastening elements. The method of claim 7, wherein Fastening element, characterized in that the diameter of the outer edge of the protrusion (34) is smaller than the smallest diameter of the underside of the head (40) of the screw (39). The method according to claim 7 or 8, The front surface of the protrusion 34 is in the form of a flat concave cone 36, When the screw head (40) is pressed, the rounded outer edge (41) of the cone (36) forms a linear contact area of increased contact pressure and provides a seal. The method of claim 5, The stud 51 has a threaded shank 52, The threaded shank 52 transitions to a face 55 abutting through a coaxial cylindrical neck 60 connected to the flange 54, wherein the cylindrical neck 60 is larger in diameter than the threaded shank 52. Fastening element, characterized in that large. The method according to any one of claims 1 to 10, In the maximum protruding region 6 the annular ring 3 may have at least one radial groove 70, 71, 72, wherein the depth of the radial groove corresponds at least to the friction welding connection. Fastening element.

Images