MXPA99009613A - Process for manufacturing an electrical connection to a metal sheet and mounting assembly - Google Patents

Abstract

The method involves using a hollow attachment element attached to the sheet part (130) with a rivet or stamp and rivet method, whereby a cable shoe (100) is attached to the hollow attachment element or sheet part by a bolt (102). The bolt is screwed into the threaded hollow attachment element through the sheet part. The sheet part can have holes pre-formed in it. An Independent claim is also included for a combined component consisting of a plate part with a protective layer and a hollow attachment element.

Description

METHOD TO MANUFACTURE AN ELECTRICAL CONNECTION FOR A PART OF METAL LAMINAR AND COMPONENTS The present invention relates to a method for manufacturing an electrical connection for a sheet metal part, in particular to a sheet metal part having a non-conductive or bad conductive protective layer, which uses a hollow fastener element which is bonded by means of a riveting process or a process of piercing and riveting to the sheet metal part, wherein a terminal lug is attached by means of a screw to the hollow fastener element, i.e., to the sheet metal part. The invention further relates to a set of components comprising a sheet metal, in particular a sheet metal part having a non-conductive or bad conductive protective layer, and a hollow fastener element riveted to the sheet metal part and designed to receive a screw that secures a terminal lug. The requirements for electrical connections for sheet metal parts, particularly but not exclusively in the sense of ground connections for automotive body parts, proved to be much more difficult. On the one hand, high-quality electrical connections are needed, so that the increasingly complicated electronic devices of motor vehicles operate correctly, in particular critical safety devices, such as for example in airbag activation systems. On the other hand, there is an increasing tendency to process the sheet metal parts that are supplied with a protective layer that only has a poor electrical conductivity or in fact has no electrical conductivity at all. In the past, a bolt element for securing ground connections proved its value, with protection in European patent EP-B-540 030. However, at present, an electrical connection that can be developed by means of an electrical connection is also required. of a nut element. As to whether, in the past, one could rely on the fact that the fastening of a fastener element with features corresponding to a portion of sheet metal would result in these shaped features damaging any present protective coating, In such a way that the desired electrical connection is given, at present it is increasingly difficult to ensure this with the laminar metal parts that are previously painted. The corresponding protective coatings are mainly designed in such a way that they can participate in the most diverse modeling methods without being damaged. These coatings are not damaged in deep drawing processes. The damage occurs when joining the fastener elements by means of riveting processes, or by means of drilling or riveting processes, so that an inadequate electrical connection between the fastening element and the sheet metal part is produced. Therefore, it is necessary to foresee the emergence of transition resistances that prevent the adequate electrical function from being ensured. In addition, laminated sheets are currently used, for example "Bondal" (trademark of the Hoesch company), which comprises two layers of steel metal and / or aluminum with an intermediate layer of plastic. However, laminated metal sheets with very good damping characteristics can only be welded under very difficult conditions, so that the production of the ground connections is only possible by means of mechanically joined fasteners, a grounding connection being necessary for both laminar metal components despite the presence of the plastic insulation layer. The object of the present invention is to provide assistance and to ensure that when using hollow fastening elements, such as clamping nuts, a high quality electrical connection is produced between the terminal lug or the terminal of the connection and the sheet metal part, even in mass production.

This object is met by a method of the kind mentioned at the beginning where the screw that is screwed into the hollow fastener element penetrates the sheet metal part and forms or re-forms a thread in the sheet metal part. A corresponding set of components according to the invention, characterized in that the sheet metal part has an orifice aligned with the bore of the hollow fastening element that receives the screw and the hole has a minimum diameter or transverse dimension that corresponds, by at least substantially, to the central diameter of the screw thread or fractionally smaller than the second. In general, the sheet metal part is drilled prior to the introduction of the screw for which there are several possibilities. On the one hand, the pre-drilling can be carried out by means of an anterior punch during the fastening of the fastening element. In this connection, for example, an embodiment of the method of the European patent application EP-A-0 759 510 can be used, as will be explained later. Suffice it to note that in the fastening of the hollow fastener element, the punch, which is concentrically guided to the central bore of the hollow fastener element, produces a corresponding hole in the lamellar metal part before the die button which supports the part of the hollow fastener element. Laminar metal forms the lamellar metal part in an empty cavity of the fastener element. If the hollow fastener elements are introduced into the sheet metal part in a progressive die tool assembly, then the pre-perforation of the sheet metal part can be performed in a station of the progressive die tool assembly, while the clamping element fastener The recess can be made in alignment with the hole thus produced in a subsequent station of the progressive stamping tool assembly. However, the sheet metal part can also be subsequently perforated, for example in a variant of the method described in EP-B-0 533 822 or EP-A-0 669 473. In a method of this kind, the connection of the Bra element to the lamellar metal part is made without piercing the sheet metal part. The continuation punch is subsequently directed through the central perforation of the fastener element to make the corresponding hole in the sheet metal part. When a progressive die cutting tool assembly is used for fastening the hollow fastener element to the sheet metal parts, fastening the fastener parts can be done in a station of the progressive die cutting tool set, where the subsequent drilling is carried out. in a subsequent station of the progressive die cutting tool set. In a preferred embodiment, a circular hole is formed in the portion of the sheet metal by means of a punch, and in fact with a diameter corresponding at least substantially to the central diameter of the screw that is fractionally smaller than the second. The purpose of this hole design is that the screw, which can be designed as a thread-forming screw or thread cutter, cuts or forms a thread in the sheet metal part, and optionally in the hollow fastener element, so that when the thread is formed in the lamellar metal part, a connection with perfect fit is obtained, that is, that the lamellar metal part molds to the screw thread. However, a circular hole is not absolutely essential. A punch with a polygonal or star-like shape or with a transverse cavity could be used. A high-quality electrical connection can be ensured by means of the screw to the terminal lug, that is, to the corresponding connection terminal through the corners or teeth of the edge of the opening that arises in this way. Any bending out of the teeth or the tips that arise in this way can also create, during the attachment of the terminal tab to the sheet metal part, a damage to the surface of the terminal ear, whereby any oxidized layer is opened and a high quality electrical connection is obtained. In the subordinate claims are the particular embodiments of the method and the set of components of the invention. The invention will be explained in more detail below with reference to the embodiments while the illustrations are described. Figures 1 to 8 correspond essentially to those of EP-A-0 759 510 Al, however, these Figures were modified to show the modified shape of the punch, the modified shape of the hole produced by the punch and the effect on the coating of the punch. protection present in the lamellar metal part. The illustrations show: Fig. 1, plan view on the opposite side of the hollow fastener element that can be used for the purpose of the invention, showing only one half of the fastener element to make it simple, Fig. 2, side view divided into sections of the fastener element of Fig. 1, Fig. 3, a schematic illustration of the first phase of the method of the invention for fastening the fastener element of Figs. 1 and 2 to a plate-like component, Fig. 3 showing to the opposite side of the die button that is used, Fig. 4, a later phase of the method of the invention just prior to piercing the component resembling a license plate. Fig. 5, a later phase of the method of the invention immediately after perforation of the plate-like component, Fig. 6, another subsequent phase of the method of the invention during the formation of the plate-like component, Fig. 7, the end of the method of the invention after the fastening of the fastener element to the plate-like component, the distribution of the punching button in the lower tool being shown in FIG. 7a. Fig. 8, a side view divided into sections of the set of components of the invention comprising the fastening element and a part of the sheet metal, Fig. 9, the fastening of a terminal ear to the assembly of components in accordance with Fig. 8 which is produced from the fastener element and the sheet metal part, Fig. 10, the finished connection, Fig. 11, a detailed representation of the electrical connection between the screw and the sheet metal part, Fig. 12, an alternative possibility for fastening a terminal lug to the assembly of components of Fig. 8, Fig. 13, a sectional view of the fastening of a hollow element to a sheet metal part in accordance with European patent EP-B-0 533 822, but with a modified punch and modified die button to produce a set of components that is designed in accordance with the present invention, and Fig. 14, a schematic illustration of the attachment of a thermowell The assembly of components of Fig. 13 is according to Figs. 1 and 2, the hollow fastener element 10 of EP-A-759 510 comprising a substantially cylindrical metal body with an opposite face 12 which, after joining the element to a plate-like component, is set aside of the last. The opposite face 12 has a ring-like cavity 14 which fits within a ring-shaped raised contact surface 16, with the base surface 18 of the ring-like cavity extending upward to the inside diameter 20 of the fastener element 10. The inner diameter 20 has a central axis 22 which at the same time represents the longitudinal axis of the fastening element and in which a threaded internal diameter is formed with a thread 24, so that the fastening element shown is a nut. The base surface 18 of the ring-like cavity 14 is connected by means of a ring flange 26 to a ring surface 28, with the outer diameter of the ring surface 28 fractionally larger than the outer diameter D of the thread 24 established in the inside diameter 20. It is noted that the inside diameter 20, ie the thread 20, the ring surface 28, the ring flange 26 and the ring-like cavity 14 as well as the contact surface 12 are in a coaxial position with respect to the central axis 22 of the fastener element 10. The opposite face 30 of the fastener element is flat in this embodiment and is provided only with a small countersink 32 which forms a clean transition to the thread 24. The stepped sleeve surface 34 of the fastener is joined by means of a small radius 36 to the opposite face 12, this radius 36 preferably being less than 0.5 mm, for example 0.3 mm. In this example, 8 cavities 38 are provided in the ring-shaped contact surface, which, as can be seen in Fig. 2, are almost wedge-shaped and their greater depth is in the transition in the side wall 15 of the ring-shaped cavity 14. In the plan view, the cavities 38 have an approximately rectangular shape as can be seen in Fig. 1. These cavities occur during the cold modeling of the manufacture of the nut and the corresponding deformation of the preform of the hollow body produces beaded projections 40 in the side wall of the ring-shaped cavity 14, these projections lead to local undercuts 41 in the side wall of the ring-shaped cavity 14, as can be see clearly on the left side of Fig. 2. All materials that have class 8 resistance values in the context of cold modeling are suitable as materials for fasteners s, for example, an alloy 35 B2 in compliance with DIN 1654. The fastening elements and the nuts thus modeled are suitable, inter alia, for all commercially available steel materials for drawing parts of quality sheet metal and also aluminum or other alloys. The nuts can also be formed with other materials, for example an aluminum alloy, in particular an aluminum alloy of higher strength. It is understood that in Fig. 2 the design of the nut on the right side of the central axis 22 is identical to that of the left side. The manner of fastening the fastener element according to Figs. 1 and 2 in a plate-like component in the form of a sheet metal part 42 will be explained in more detail below with reference to Figs. 3 to 8. In Fig. 3 the fastening element 10 according to the invention is shown in an adjustment head 44 illustrated only partially having a plunger 46 and also a punch 48 positioned coaxially to the plunger 46. A positioning head of this kind is known in principle from the German documents mentioned, that is to say German patent 34 46 978 and the published but not revised report 38 35 556.3. Punch 48, which is referred to herein as a front punch, has at its front end a cylindrical section 49 of smaller diameter that actually performs the drilling process, as will be explained in more detail below. Beneath the sheet metal part 42 there is a die button 50 which, as shown in Fig. 7a, is inserted for example as a cylindrical component into a cylindrical inner diameter 51 of an inferring tool 52 by means of a spacer 54 The die button 50 has a central inner diameter 56 which is joined by means of a ring flange 58 to a larger internal diameter 60. The opposite face 62 of the die button 50 has a flat surface 64 which is at the level In addition, the opposite face of the punching button 50 has a piercing punch section 68. The inner diameter 56 that forms the projection hole of the piercing punch 68 has a cutting edge similar to that of the piercing punch 68. a ring 70, having an inner diameter corresponding to the diameter of the cylindrical section 49 of the punch 48, i.e., it is only fractionally larger than the same, as is usual with punches. This diameter is much smaller than the diameter of the central hole of the hollow fastening element, that is to say, of the threaded cylinder 24. The reason for this will be explained later. The opposite face 72 of the die button which is positioned axially to the longitudinal axis 22 and which is at least substantially perpendicular to this axis has a rounded round edge 74 at the transition to the jacket surface of the piercing punch section 68. A plurality of projections 76 are distributed in intervals around the perforation punch section, six of these projections for this embodiment being uniformly disposed around the section of the punch punch 68. The projections 76 have an inclined surface 78 and are formed in elevation, both on the jacket surface of the projection of the piercing punch 68 and also on the opposite flat face 64 of the die button 50.

The projections 76, which are completely round on all surfaces, are somewhat less wide than the cavities 38 in the contact surface similar to a ring 16 of the nut 10. Using the same number 22 as reference, it is clear that the punch 48, the punch 46, the lower surface 77 of the adjusting head, the hole 10 and the punching button 50 of the lower tool 52 as well as the inner diameter 56 and the inner diameter 60 of the punching button and finally also the through-drilling of the separator 54 has coaxial positions. The position of the positioning head 44 is in a manner known per se in the upper tool of a press and it is designed in the usual manner and using normal means for the respective nuts to pass through an inclined passage. in the inner diameter 80 of the laying head 44 and then directed by means of the plunger 46 during the closure of the press upwards to the opposite face of the laying head. During this movement, the nuts for the known apparatuses can also be clamped, for example from the PCT application with the publication number WO 93/19890. During the closure of the press, for example for modeling the sheet metal part by means of the lower tool 52 in combination with a top tool not illustrated, the positioning head moves out of the position of FIG. 3 to the position of Fig. 4. The opposite lower face 77 of the positioning head 44 thus comes into contact with the sheet metal part 42 and this in turn is pressed against the opposite face 72 of the die button 50. A Further movement downwardly of the box 79 of the positioning head, which serves as a holding member for the sheet metal part 42, is avoided in this step, the box 79 of the positioning head is somehow diverted backwards with relationship to the tool that moves down from the press. This also applies to the plunger 46 which presses against the ring flange 35 of the fastening element, and not against the opposite face 31, so that the danger of damage to the thread 34 is effectively prevented. However, the upper tool the press pushes the punch further downwards, mainly in the position of Fig. 5. During this, the section of the punch 49 cuts a piece 82 of the sheet metal part 42 together with the cutting edge 70 of the section of the perforating punch 68 of the punching button 50, as shown in the sequential illustration of Fig. 5. In this way a perforated hole is formed in the sheet metal part 42. In this illustration it can be seen that the punch section 49 it is received with sliding on the inner diameter 56 of the die button 50. The piece 82 can be removed through the inner diameter 60 as compared to the inner diameter 56 ensuring that the piece moves easily under gravity and do not get stuck or stuck. During the further closing movement of the press, the box 79 of the positioning head 44 and the plunger 46 move together further downwards, as shown in Fig. 6, whereby the section of the punch punch 68 or said in more precisely, the stretched round edge 74 of the projection of the piercing punch forms a collar 75 of the laminar metal part around the pierced hole 83 while the pierced hole 83 is widened. This deformation is continued until the final stage as shown in FIG. Fig. 7 and in this figure it can be seen that the projection of the piercing punch 68 has the laminar metal material of the collar 75 so deformed that it is tightly pressed in the ring-shaped cavity 14 of the fastening element and in the undercutting 40 The diameter of the perforated hole 83 before said widening corresponds to the diameter of the cylindrical section 49 of the punch 48 and is selected so that, after broadening, the enlarged perforated orifice has an internal diameter that is at least substantially identical to the central diameter of the threaded cylinder fractionally smaller than the second. By means of the different number of protrusions 46 compared to the number of cavities 38 in the ring-like contact surface 16 of the fastener element it is ensured that at least one protrusion is completely aligned with a cavity 38, and in fact without need to take measures to ensure the rotational position of the fastener element around the central axis 22. At least partial alignment with the projections of the punching button of the other cavities 38 can be expected, so that a tight contact also occurs , by means of which it is assured that there is no rotation. Because the bead-shaped projections 40, which form the undercuts, also lead to a corrugated surface of the side wall of the ring-shaped cavity 14, the tight contact of the sheet metal part against this side wall also makes a significant contribution for the rotating security of the connection. According to the state of the method of Fig. 7, the press is opened again and the workpiece 42 with the attached fastener is ejected from the press or withdrawn therefrom and then shown in Fig. 8. It can be seen in Fig. 8 that the inner diameter of the collar 75 of the sheet metal part 42 is somewhat smaller than the inside diameter of the thread 24, so that the sheet metal part can initially hinder the insertion of a bolt in contrast to the previous function of the fastener element. The bolt, which fits into the thread 24, is generally inserted in the narrow direction 86 of FIG. 8 and normally serves to secure a second component of sheet metal to the sheet metal component 42. They are also evident in FIG. 8 the cavities 88 produced in the sheet metal part by the projections 76. The sheet metal part 42 of Fig. 8 is subdivided by a dotted line 43, which indicates the possibility of using laminated metal sheets and represents the plastic layer between the two lamellar metal components of steel and / or aluminum. Although all fastener elements presented in this document have a cylindrical straight jacket surface, ie all have a circular cross-section in plan view, other cross-sectional shapes can also be used, for example polygonal or oval or transverse shapes that have indentations It should further be understood that the term "ring-shaped" includes not only circular rings, but also ring shapes that differ in some way from the circular ring shape, such as for example a polygon. The side wall 41 of the ring-shaped cavity 14 can also represent a polygon or a multi-sided figure. Fig. 9 shows how a terminal lug 100 is installed by means of a screw 102 in the set of components comprising the hollow fastening element and the sheet metal part 42. In contrast to the hollow fastening element of the previous Figures, in FIG. present one embodiment is shown only as an alternative, where the threaded cylinder 24 is not yet present, ie the corresponding central passage of the fastener element has an inner diameter corresponding to the central diameter of the thread. The terminal lug 100, which may also be a connection terminal, for example as a clamping lug for an ignition coil, has a hole 104 with a diameter larger than the outside diameter of the threaded portion 106 of the screw 102, so that the screw can pass through without resistance the terminal lug 104. The screw 102 is also called Taptite screw (registered trademark), which can be obtained in the market and represents a screw forming thread. The thread forming screw 102 is placed in the hollow fastening element and screwed into it by means of a suitable tool which engages in the head part 108 of the screw. The turns of the screw thread formduring the threaded movement inwards, a clearance and a free connection of settlement both with the fastening element and also with the walls of the hole of the sheet metal component and thereby a tight contact with the clamping screw for the ground wire. That is, the electrical connection is produced from the cable lug to the screw and from the threaded part of the screw to the sheet metal part. In this connection it is not important if the fastening element 10 is coated with a paint or only has a metallic protection coating against oxidation. The electrical connection between the screw and the terminal lug can be optionally improved by traditional means, for example by means of a spring washer equipped with tips. It is not absolutely essential that the screw itself forms the threading in the hollow fastener element. The fastener element 10 can, as shown in Figs. 1 to 8, present as a nut element and then only serve as a guide to the screw which, however, would have to cut the thread in the sheet metal part. However, it would also be possible to pre-form the thread in the sheet metal part, optionally with smaller dimensions, and then only give it the final shape when the screw is inserted. Fig. 10 shows the finished connection. The ring-shaped contact of the lower side of the head part of the screw that is against the terminal lug and the terminal lug against the nut element represents a high quality electrical connection between the screw and the terminal lug, which can , if required, be improved by means of a spring washer provided with tips. Particularly favorable is the full-area support of the terminal lug over the entire surface of the ring-shaped contact by means of the nut element. Fig. 11 shows how a thread turn 112 of the arrow portion 106 of the screw 102 forms a corresponding thread turn in the sheet metal part 42. It can also be used in place of a thread forming screw, a cutter screw of threads. Fig. 12 shows one more possibility of joining the screw. In this, the part 108 of the screw is placed on the side of the sheet metal part remote from the nut 10. The electrical connection also extends from the terminal tab by means of the screw in the sheet metal part. The arrangement of Fig. 12 has the additional advantage that the screw aids the connection between the hollow fastener element 10 and the sheet metal part 42, however, in some circumstances it requires a design of a larger area of the lug. terminal 100 or the contact surface of the head part 108 of the screw, so that the pressure of the surface on the terminal ear or on the screw is kept within reasonable limits. Otherwise, all the details for the embodiment of Fig. 9 are given which also apply to the embodiment of Fig. 12. That is, among other things, that a thread-forming screw or a screw thread cutter. In the embodiment of figure 14, a ring-like contact of the lower side of the screw head part against the terminal tab and a ring-like contact of the terminal tab against the sheet metal part also take place, and effectively in the region where the sheet metal part is supported in a manner similar to a ring and on the filled area against the surface (12) of the ring-shaped contact of the nut element, so that an electrical connection is also achieved here High quality between the screw and the terminal ear. The electrical connection in accordance with the present technique can not be obtained with only one element according to European application EP-A-0 759 510 Al. Basically, all known nuts and lamellar metal connections can be considered where the possibility exists that the lamellar metal part remains in the region of the corresponding passage opening of the hollow fastener element and provide it with a hole corresponding at least substantially to the central diameter of the screw thread. In other words, the present invention can be used at least with laminar metal connections of fasteners, such as described in German patent 34 01 118, in European patent 0 533 822, European patent 0 669 473 or in the patent application European still not published 97 116 188.0. The mentioned protection rights belong to the company Profil Verbindungstechnik GmbH & amp;; Co. KG or in which Profil has obtained the rights. However, to be able to use the present invention, competitive products can be modified. For example, the element shown in European patent EP-B-0 663 247 could be modified to form a set of components according to the present application. To further explain these concepts, reference is made to the following Figs. 13 and 14. Fig. 13 shows in principle the nut of European patent O 533 822, the drawing of which can be considered representative of the nuts of European patent application EP-A-669 473 or European patent EP-B-663 247. The element shown with reference number 120 has a ring-shaped cavity 122 with a radially inner side wall 124 and a radially outer side wall 126, the radially inner side wall of the ring-shaped cavity 122 representing the radially outer wall of a cylindrical projection or pilot 128 that in the previous use of the nut served as a cylindrical punching section. With such an element it is important that the radially outer side wall 126 and / or the radially inner side wall 124 be at least locally recessed, so that the entrance to the ring-shaped cavity 122 in the region of the surface contacting the corresponding element 120 against the sheet metal part 130 is smaller than the base surface of the ring-shaped cavity 122, to allow a corresponding hooking engagement with the sheet metal part. The die button has a ring-shaped projection 132 which at the junction of the element pushes the sheet metal material into the ring-shaped recess 122. To provide a security against rotation there are several possibilities to provide shape. However, these are not an element of the present invention and are explained by themselves in the specifications of the mentioned patents or the application documents. They will not be explained in more detail in the present. Two features are important in the present embodiment. On the one hand, the die button has a ring-shaped cavity 134 on its end face, so that during the production of the connection between the element and the sheet metal part, the cylindrical cross-section 128 can not perform any action of perforation, but rather that presses the laminar metal portion so as to produce a bowl-shaped cavity 136. In this embodiment a continuation punch is used. That is, after production of the connection in accordance with Fig. 13, the punch 138, designed in accordance with the punch 48 of the embodiment of Figs. 1 to 8 and having a cylindrical region of smaller diameter 139, is pressed downward, so that the diameter of a smaller section at the leading end of the punch pierces a piece 140 of the sheet metal part 130 together with the die button and the piece 140 can be eliminated by means of the central passage 142 of the die button 144 in the usual manner and means. During this process the front section 139 of the punch forms a circular opening 146 in the sheet metal part 130 with a fractionally smaller diameter than the inner diameter of the central passage 148 of the hollow fastener element 120 which has not yet been threaded. In the present embodiment, the widening of the perforated hole is not expected or needed since the laminar metal part 130 already has its final adjustment connection with the fastening element 120.

After the removal of the set of components from the press, ie the set of components comprising the sheet metal part 130 with the nut 120 riveted thereto, a terminal lug or a connection terminal 100 can be secured to the set of components by means of a corresponding screw 102, as shown in Fig. 14. During this, the thread forming screw or thread cutter 102 cuts or forms a thread in both the sheet metal part 130 and the wall of the central passage 148 of the hollow fastener element 120, so as to produce a high quality electrical connection extending from the terminal lug by means of the screw to the sheet metal part 130. Because the bottom surface of FIG. 14 of FIG. The cylindrical section 128 of the hollow fastener element 120 projects somewhat further than the contact surface in the region of the edge of the hollow fastener element 120, it is sure that the Terminal pad 100 has contact with the central part of the sheet metal part and thereby ensures an adequate contact pressure force between the head part 108 of the screw and the terminal ear 100, which favors the electrical connection. Here also a ring-shaped contact between the lamellar metal part and the terminal ear and the screw in the region of the terminal ear, as well as a ring-shaped support of the filled area of the lamellar metal part in the ring, is present. the nut element, which likewise favors the quality of the electrical connection. A spring washer with tips may also be used if considered necessary. Basically, in the embodiment of Fig. 14, the screw could also be introduced from the other side, as shown in the embodiment of Figure 10. If the screw originates both the threading of the nut 120 and the lamellar metal part, then the connection between the element hollow fastener 120 and the lamellar metal part must be sufficiently strong so that the corresponding torsion, which arises during the cutting of the threads or the formation of the threads, does not produce a loose connection between the element 120 and the laminar metal part 130. Although the embodiments described above always operate using an anterior punch or continuation punch, there is also the possibility of producing the corresponding hole in the sheet metal part by means of a tapping screw which must be positioned or guided accordingly, for which the hollow passage or the threaded cylinder of the fastener element could serve, however, this embodiment is not It is in the background of this invention, since there is a danger that the sheet metal part could be separated from the nut.

Claims (23)

Claims

1. Method of manufacturing an electrical connection for a sheet metal part, in particular to a sheet metal part having a non-conductive or bad conductor protective layer, using a hollow fastener element which is joined by means of a riveting process or a process of drilling and riveting the lamellar metal part, wherein the terminal lug is attached by means of a screw to the hollow fastener element, that is, to the lamellar metal part, the lamellar metal part, which is characterized in that the screw that is screwed into the hollow fastener element penetrates the sheet metal part and forms or re-forms a thread in the sheet metal part.

Method according to claim 1, characterized in that the lamellar metal part is perforated beforehand.

Method according to claim 2, characterized in that the pre-drilling is carried out by means of an anterior punch during the joining of the fastening element.

Method according to claim 2, characterized in that the pre-perforation of the sheet metal part is carried out in a station of a progressive die-cutting tool assembly while the hollow fastener element is joined in alignment with the hole preformed in a subsequent station of the progressive die cutting tool assembly.

The method according to claim 1, characterized in that the lamellar metal part is then perforated.

Method according to claim 5, characterized in that the subsequent perforation is carried out during the joining of the hollow fastening element by means of a continuation punch.

Method according to claim 5, characterized in that the attachment of the fastening element is carried out in a station of a progressive die cutting tool assembly and the subsequent perforation of the sheet metal part in alignment with the hollow fastening element is carried out in a subsequent station of the progressive die cutting tool set.

Method according to one of the preceding claims 2 to 7, characterized in that the anterior punch- or the continuation punch forms a circular hole in the sheet metal part with a diameter corresponding at least substantially to the central diameter of the screw or is fractionally smaller than the second.

Method according to one of claims 2 to 7, characterized in that the previous punch or continuation punch has a polygonal cross-section or a star-shaped cross-section with teeth and optionally cooperates with a die-cutting button that supports the sheet metal part and has an opening having a corresponding cross section.

Method according to one of the preceding claims, characterized in that the screw is created as a screw thread or thread former and cuts or forms the thread in the sheet metal part and optionally also in the hollow fastener element.

The method according to claim 1, characterized in that a thread or thread former screw is used which pre-perforates the sheet metal part and which is optionally guided by the hollow fastener element.

Method according to one of the preceding claims, characterized in that the screw has a head and the hollow fastening element.

Method according to one of the preceding claims 1 to 11, characterized in that the screw has a head and the terminal ear is clamped between the head and the sheet metal part.

14. A set of components comprising a lamellar metal part, in particular a lamellar metal part having a non-conductive or bad conductive protective layer, and a hollow fastener element riveted to the lamellar metal part and designed to receive a screw that secures a terminal lug, characterized in that the sheet metal part has a hole that is aligned with the passage of the hollow fastening element that receives the screw and the hole has a diameter or a minimum transverse size that corresponds at least substantially to the central diameter of the thread or the screw or that is fractionally smaller than the second.

15. Set of components according to claim 14, characterized in that the screw is screwed into the hollow fastening element and penetrates the sheet metal part and that the edge of the hole is formed in accordance with the screw thread, the screw being screwed both in the hollow fastening element and in the the laminar metal part.

Assembly of components according to one of claims 14 to 15, characterized in that the hollow fastening element is a nut provided with a thread before joining.

Assembly of components according to one of claims 14 to 16, characterized in that the screw is a thread former or thread cutter which optionally not only cuts or forms the thread in the sheet metal part, but also in a hollow fastener element.

18. Set of components according to one of claims 14 to 17, characterized in that the screw has a head and the terminal ear is clamped between the head and the hollow fastener element.

Assembly of components according to one of claims 14 to 18, characterized in that the screw has a head and the terminal lug is clamped between the head and the sheet metal part.

Component set according to one of claims 14 to 19, characterized in that the hollow fastening element is an element in accordance with European patent application EP-A-0 759 510, for example in the form of a nut RSU of the company Profil Verbindungstechnik GmbH & Co. KG.

The assembly of components according to one of claims 14 to 20, characterized in that the hollow fastening element is an element in accordance with the specification of German patent 34 04 118, for example in the form of a UM nut of the Profil company Verbindungstechnik GmbH & Co. KG.

22. Assembly of components according to one of claims 14 to 21, characterized in that the hollow fastening element is an element in accordance with European patent EP-B-0 533 822.

23. Set of components according to one of the claims 14 to 22, characterized in that the hollow fastener element is an element in accordance with European patent application EP-A-0 669 473.