Electrical contact element and rivet assembly for forming such a contact element

Abstract

An electrical contact element with a first planar connection (2) and with at least one second connection (3) designed as a terminal pole and in electrically conductive connection with the first connection (2), characterized in that the first and second connections are each provided by separate connection elements (2, 3) connected to each other by a rivet assembly (12), in that the planar connection element (2) forming the first connection has a number of terminal pole recesses (5) corresponding to the number of second connections, the depth of which is limited by a base (6), and the terminal pole(s) as second connection elements (3) are equipped with a clamping head (9) whose thickness is less than the depth of a terminal pole recess (5), and in that the rivet assembly (12) is designedso that the edge region of the first connection element (2) enclosing a connection pole recess (5) is at least partially transformed to overlap the clamping head (9).

Description

[0001] The invention relates to an electrical contact element comprising a first planar connection and at least one second connection designed as a terminal pole and in electrically conductive connection with the first connection. Furthermore, the invention relates to a rivet assembly, in particular for forming such a contact element.

[0002] Electrical contact elements of the type described above are used, for example, as connection contacts in battery cell modules. Such a battery cell module has two externally accessible connection contacts for connecting the module to a power grid, such as that of a motor vehicle, or to other battery cell modules. The two connection contacts, of opposite polarity, are accessible from the outside. Such an electrical contact element has two terminals: a first terminal connected to the battery cells and a second terminal designed as a connection pole for external contact with the battery cell module. This type of electrical contact element is preferably manufactured as a single piece.

[0003] The first flat contact of such a contact element is many times larger than the base area of ​​a terminal projecting from the first contact. For this reason, such an electrical contact element cannot be manufactured, or can only be manufactured with considerable effort, solely by forming processes such as pressing or forging. Typically, such contact elements are made from a suitable aluminum or copper alloy. Sometimes, the battery terminals of such a battery cell module, provided by these contact elements, are made from different materials, for example, the positive terminal from an aluminum alloy and the negative terminal from a copper alloy.

[0004] In view of the complex manufacturing process, the invention aims to propose an electrical contact element of the type mentioned above, in which not only the manufacturing process is simplified, but also the possibility of greater variability is created.

[0005] This problem is solved according to the invention by an electrical contact element of the aforementioned type, in which the first and second connections are provided by separate connection elements connected to each other by a rivet assembly, in that the planar connection element forming the first connection has a number of connection pole recesses corresponding to the number of second connections, the depth of which is limited by a base, and the connection pole(s) as second connection elements are equipped with a clamping head whose thickness is less than the depth of a connection pole recess, and in that the rivet assembly is designed so that the edge region of the first connection element enclosing a connection pole recess is formed at least section by section to engage the clamping head.

[0006] This electrical contact element cleverly utilizes the flat, plate-like design of the first connection and the relatively large base area of ​​a second connection element, designed as a terminal, to join both elements using a riveted connection without requiring a penetration in the first connection element. This ensures the gas tightness required for certain applications, such as use as a terminal contact in a battery cell module. To create the riveted connection, the flat connection element has a terminal recess, defined by a base, which is integrated into a flat side of the first connection element. The terminal recess does not extend through the first connection element. The base ensures gas tightness.The second terminal element, designed like a connecting pole, has a clamping head at its end to be joined to the first terminal element. The thickness of the clamping head, i.e., its axial extent, is less than the depth of the terminal recess of the planar connecting element associated with this terminal pole. The clamping head projects radially from the circumferential surface of the section adjacent to the clamping head, like a collar, thus creating an undercut when viewed from the terminal recess of the first terminal element. For the rivet connection to be formed, it is sufficient if this undercut is provided by a groove adjacent to the clamping head. The outline geometry of the terminal recess and that of the clamping head are identical.The cross-sectional area of ​​the terminal pole recess is dimensionally matched to that of the clamping head, so that the latter preferably fills the terminal pole recess almost completely. A certain amount of play for inserting the clamping head of the terminal pole is generally provided. Due to the clamping head being thinner than the depth of the terminal pole recess, the material of the first connection element surrounding the terminal pole recess projects beyond the clamping head inserted into the terminal pole recess.

[0007] To create the desired rivet connection, at least in sections, the edge region surrounding the connection pin recess of the first connecting element is plastically deformed to allow the clamping head to engage. This can be easily achieved by a pressing process with an annular punch, which is pressed onto the edge region of a connection pin recess using a press. In this way, material is pressed radially from the edge region of the first connecting element into the connection pin recess to engage over or behind the clamping head of a connecting pin inserted therein. The forming process creates a recess in the first connecting element at a distance from the actual edge of such a connection pin recess.Preferably, the rivet assembly is continuous around its entire circumference to engage the clamping head of a terminal pole. The aforementioned press recess is then a circumferential groove. As a result of the material flow caused by the pressing process, any gap that may exist between the outer surface of the clamping head and the circumferential wall of the terminal pole recess is also filled. Consequently, in the rivet assembly, the clamping head not only makes full contact with the bottom of the terminal pole recess, but also contacts the inner wall of the terminal pole recess with its circumferential outer surface. Furthermore, the contact surfaces are typically subjected to a certain preload by the forming process, so that the two-part design of such a contact element is not detrimental with regard to the required electrically conductive connection between the two terminal elements.According to a preferred embodiment, such a connection pin recess is created by a pressing operation, utilizing this effect caused by the forming process. In such a case, machining to form such a connection pin recess is not necessary – although certainly possible. Pressing such a connection pin recess in with a punch can, due to the associated material displacement, result in the formation of a circumferential bead in the edge region surrounding the connection pin recess. This is even advantageous for the forming process to create the rivet joint, since, depending on the thickness of the rivet head, more material is then available for the forming process to create the rivet joint.The larger material reservoir also allows the lateral surface of the second connection element bordering the clamping head to be contacted by the formed material, especially if the amount of the overhang of the clamping head is somewhat larger.

[0008] A further advantage of designing such an electrical contact element is that different materials can be used for the two terminals. Another advantage is that, due to its planar design, it is readily possible to connect several second terminal elements, each with its own riveted connection, to a first terminal element if required.

[0009] If such an electrical contact element is for a battery cell module, it goes without saying that these terminals will have the same polarity.

[0010] Such a terminal typically has a cylindrical surface. The shape of the surface depends on the desired connection. The surface can also be conical, tapering towards the free end. The surface of such a terminal can also be stepped. The first, flat contact element is, according to one design, plate-like and has a planar extent. Due to the size of this flat surface, sufficient surface area is provided to weld or solder it to battery cells, for example. An advantage of the two-part design of the contact element is that the flat contact element, while it can be a flat plate, can also be curved or even angled.

[0011] The invention is described below with reference to an exemplary embodiment and the accompanying figures. These show: Fig. 1: A perspective view in the manner of an exploded view of an electrical contact element according to the invention, Fig. 2: a top view of the in Fig. 1 recognizable flat side of the first planar connecting element of the contact element of the Fig. 1, Fig. 3: an enlarged cross-sectional view along line AB of the Fig. 2, Fig. 4: the electrical contact element of the Fig. 1 with its connecting elements joined together by a rivet connection, Fig. 5: an enlarged section through the electrical contact element of the Fig. 4 according to the in Fig. 2 shown section line AB and Fig. 6a - 6c: Process steps for manufacturing the electrical contact element of the Fig. 4.

[0012] An electrical contact element 1 comprises a first, planar, flat-plate-shaped connection element 2 and a second connection element 3, designed as a terminal pole, as known from batteries. Into the Fig. On the first connecting element, a terminal pole recess 5 is provided on the recognizable flat side 4. As can be seen in the figure, the depth of the terminal pole recess 5 is less than the thickness of this connecting element 2. The depth of the terminal pole recess 5 is limited by a base 9. The second connecting element 3, which serves as a terminal pole, has a cylindrical surface. With the exception of one section, this is a cylindrical surface. Fig. 1. A recognizable end face 7 contains a conical recess 8 around a solid material body. The connecting element 3 has a clamping head 9 that projects radially beyond the adjacent section 10. The thickness of the clamping head 9 is less than the depth of the connection pole recess 5 of the first, flat connecting element 2. In the illustrated embodiment, the section adjacent to the clamping head 9 is stepped, with the larger diameter section 10 bordering the clamping head 9.

[0013] In the illustrated embodiment, both connecting elements 2, 3 of the electrical contact element 1 are made of an aluminum alloy suitable for the purposes.

[0014] In the illustrated embodiment, as can be seen in the figures, the connecting pole provided by the second connecting element 3 is arranged off-center with respect to the extent of the compartment side 4 of the first connecting element 2. The cross-sectional geometry of the connecting pole recess 5 is shown in the enlarged sectional view of the Fig. 3 recognizable. The base 6 ensures a tight seal between the side carrying the connection pole 3 and the opposite side of the connection element 2.

[0015] Fig. Figure 4 shows the two connection elements 2 and 3 of the electrical contact element 1 in their assembly. The second connection element 3, representing the terminal pole, projects from the flat side 4 of the first connection element 2. Both connection elements 2 and 3 are permanently joined together by a rivet. The rivet itself is shown in the sectional view of the Fig. 5. The clamping head 9 of the second connection element 3 is permanently pressed firmly into the terminal pole recess 5 of the first connection element by the rivet connection. This ensures the desired electrical connection between the two connection elements 2 and 3. With its base surface 11, the connection element 3, which provides the terminal pole, contacts the bottom 6 of the terminal pole recess 5. In addition, the outer surface of the clamping head 9 and the adjacent first part of section 10 of the connection element 3, which is pressed against it as a result of the rivet connection, contact the material of the first connection element 2. The rivet connection is in Fig. 5 is identified by reference numeral 12. This is circumferential. The rivet joint 12 is provided by a pressing process of the edge area of ​​the flat side 4 of the connecting element 2, which surrounds the connecting pole recess 5, forming a circumferential recess 13. This recess is created by the action of an annular rivet punch 14. This punch deforms the material surrounding the connecting pole recess 5 to engage over or behind the clamping head 9 and to press it against the outer surface of the connecting element 3.

[0016] Figures 6a to 6c schematically depict the steps for the production of the riveted joint 12. Fig. 6a shows the one in Fig. Section 3 of the first connecting element 2 shown, with the connecting pole recess 5 incorporated therein and the second connecting element 3 inserted therein with its clamping head 9. By means of an annular riveting punch 14, which is in Fig. As shown in section 6b, the riveting process is carried out. During the riveting process, the riveting punch 14 engages the connecting element 3 in a slight manner and its end face 15 acts on the edge region of the connecting element 2 that surrounds the connection pole recess 5. In the illustrated embodiment, the end face 15 of the riveting punch 14 is rounded, with the inner radius of curvature being larger than the outer radius of curvature facing the connection pole 3. This provides a contact or pressing surface through which material from the edge region surrounding the connection pole recess 5 is displaced towards the connection pole recess 5 and thus towards the clamping head 9 or the outer surface of the connection pole 3. Fig. Figure 6c shows the state of the riveting punch 14, in which its end face 15 acts on the flat side 4 of the connecting element 2. The stroke of the press carrying the riveting punch 14 continues until the annular recess 13 has formed in the flat side 4 of the connecting element 2, i.e., until sufficient material has been compressed to create the desired riveted joint, as shown in Figure 6c. Fig. 5 shown, to achieve.

[0017] The riveted joint described above serves as an example for forming an electrical contact element. It is also suitable for numerous other applications.

[0018] The invention has been described using exemplary embodiments. Without departing from the scope of protection described by the applicable claims, numerous further embodiments of the inventive concept would be apparent to a person skilled in the art, without these needing to be explained in more detail within the scope of these explanations. Reference symbol list 1 Electrical contact element 2 First connection element 3 Second connection element / connection pole 4 flat side 5 terminal recesses 6 Floor 7 Front 8 In-depth study 9 Clamping head Section 10 11 Base area 12 riveted joint 13. Further Study 14 rivet stamps 15 Front

Claims

[1] Electrical contact element with a first planar terminal (2) and with at least a second terminal (3) designed as a terminal pole and in electrically conductive connection with the first terminal (2), characterized by, that the first and second connections are each provided by separate connection elements (2, 3) connected to each other by a rivet assembly (12), in that the planar connection element (2) forming the first connection has a number of connection pole recesses (5) corresponding to the number of second connections, the depth of which is limited by a base (6), and the connection pole(s) as second connection elements (3) are equipped with a clamping head (9) whose thickness is less than the depth of a connection pole recess (5), and that the rivet assembly (12) is designed so that the edge region of the first connection element (2) enclosing a connection pole recess (5) is at least partially formed to overlap the clamping head (9). [2] Contact element according to claim 1, characterized by, that the edge area of ​​the first connection element (2) enclosing a recess (5) is continuously transformed to overlap the clamping head (9) of a connection pole. [3] Contact element according to claim 1 or 2, characterized by , that at least one terminal pole (3) has a cylindrical surface. [4] Contact element according to any one of claims 1 to 3, characterized by , that the first connecting element (2) has a planar extent that exceeds the base area of ​​the clamping head (9) of a connecting pole (3) by a multiple. [5] Contact element according to any one of claims 1 to 4, characterized by , that the first connecting element (2) is a flat plate. [6] Contact element according to any one of claims 1 to 5, characterized by , that the first connecting element (2) and the at least one second connecting element (3) are made of the same material. [7] Contact element according to any one of claims 1 to 5, characterized by that the first connection element and at least one second connection element, or at least one of the two connection elements, are made of different materials. [8] Contact element according to any one of claims 1 to 7, characterized by , that the contact element (1) has a single second connection element (3). [9] Rivet assembly, in particular for forming an electrical contact element according to one of claims 1 to 3, comprising a first planar element (2) and at least one pin-like second element (3) projecting from it, wherein the first planar element (2) has a number of recesses (5) corresponding to the number of second elements (3) to be connected to it, the depth of which is limited by a base (9), and the second element(s) (3) are equipped with a clamping head (9) whose thickness is less than the depth of a recess (5) of the first element (2), and that the rivet assembly (12) is designed so that the edge region of the first element (2) enclosing a recess (5) is formed to engage the clamping head (9) of the second element (3). [10] Riveted joint according to claim 9, characterized by, that the edge area of ​​the first element (2) enclosing a recess (5) is continuously transformed to overlap the clamping head (9) of a connecting pole. [11] Riveted joint according to one of claims 9 to 10, characterized by , that the first element (2) has a planar extent that exceeds the base area of ​​the clamping head (9) of a terminal pole (3) by a multiple. [12] Riveted joint according to one of claims 9 to 11, characterized by , that the first connecting element (2) is a flat plate. [13] Riveted joint according to one of claims 9 to 12, characterized by , that the first element (2) and at least one second element (3) are made of the same material. [14] Riveted joint according to any one of claims 9 to 13, characterized by that the first element and at least one second element, or at least one of the two elements, are of different materials.

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