A cabling arrangement assembled in a sandwich structure and intended for motorised vehicles

Abstract: The present invention relates to a cabling arrangement for motorised vehicles and similar comprising a system for electrical power supply and a system of data transmission via a busbar (1) to which components signals are addressed separately using a multiplexing process. This arrangement has at least one busbar (1) with at least two power conductors (2, 3) for the supply of electrical power to components and at least two conductors (4) used by the busbar data transmission system (1). All the conductors (2,3,4) are in the form of metal strips and are separated one from another by insulating sheet material (5) and assembled in a laminated or "sandwich" structure, each component or a secondary busbar taking off control or power current from the busbar through their respective connectors.

Description: The present invention relates to a cabling arrangement intended for motorised vehicles or similar as described in the introduction to claim 1. Such a cabling arrangement is known from DE-U-298 13 878. Cabling arrangements, whose functioning is based on a system for transmitting data via a busbar, are further known, as for example in the article "Neue Werkstoffe und Techniken für die Verkabelung im Automobil" [New materials and techniques for automotive cabling] by Reinhard Feigenbauer, published in the journal ATZ Automobiltechnische Zeitschrift 99 (1997), issue 3, pages 148 et seq . The development of the cabling arrangement shown here derives from the need to make a substantial reduction in the number of individual cables in motorised vehicles, thereby reducing the weight of the cable bundle. It is estimated that when completely fitted out, a high-end car contains up to 80 servomotors and that the management of the monitoring and control functions of the motor and the various programs for vehicle stability and steering need an increasing number of sensors. The weight as such of a conventional cable bundle is therefore becoming a central problem and is holding back further technical development. For this reason, the idea was conceived of installing systems for the transmission of data via loop circuits, with each component possessing a multiplexed connection plug in order to collect from that component specific information or to send information along the loop. Such data transmission generally involves the use of currents of several tens of milliamps and a voltage in the region of 5 volts. Sensitivity to external interference and interference caused to the control signals carried in neighbouring cables are however a source of difficulty. In addition, the busbar systems described do not possess current supply lines for specific components as conventionally connected with lines carrying currents of 160A at a voltage of 12V. The use of such a busbar already enables a considerable reduction to be made on the number of cables installed. The complete network is nevertheless complex and sensitive to electromagnetic interference. DE-U-298 13 878 describes a busbar system having three power conductors 3, 4 and 5 as shown in its Figure 1. The system according to this document further contains a conductor 7 for transmission of data. As can be seen in Figure 1 the conductor transmitting the data 7 is on top of all power conductors. The conductor 7 is not protected from EMI/RFI so that an outer shielding 8 is necessary. According to the claimed invention, however, this outer shielding is not necessary as the two power conductors form a condenser and protect the two control conductors inside the condenser. Therefore, an effective shielding is obtained, a further extra shielding is not necessary. US 4,382,156 shows a busbar having two conductors 14. A control conductor for the busbar data transmission system between two power conductors is not disclosed. US 3,893,233 relates to a power distribution system busbar having ground planes and power signal conductors. This document describes a way for connecting the different conductors to other components using a hole and pins. The present invention relates to a cabling arrangement for motorised vehicles or similar, enabling the cabling to be substantially simplified and its weight considerably reduced, with an accompanying significant reduction in sensitivity to electromagnetic interference. This goal is attained using cabling in accordance with claims 1. Preferred embodiments of the invention are described in the sub-claims. The concept underlying the present invention involves the manufacture of power conductors and control conductors in the form of thin strips or sheets, arranged in a "sandwich" configuration and separated one from another by sheet material offering high insulation. This arrangement is advantageous compared with metal wires with an essentially round cross-section in that the busbar thus formed act as capacitors in a manner such that data transmission is protected from external interference. Moreover, such busbar can be shaped with ease and lend themselves to easy fitting, which may also be automated. They offer, compared with the bundled cable systems described above, a weight saving which may attain one-third according to the model. Its rigid construction reduces the risk of confusing different connections and simplifies assembly. The large conductor cross-section and the materials used combine to obviate any notable voltage fall along the busbar. In addition, prior to assembly, the busbar may be ready-shaped to take account of the location at which they are to be fitted, following the contours of the chassis or the metalwork of the vehicle, with the result that an arrangement occupying very little space is possible. The invention is described in detail below using descriptions of examples of embodiments and with reference to the drawings, in which: Figure 1 is a diagram showing the structure of an example of a busbar cabling arrangement for understanding the invention; Figure 2 shows an arrangement of the lines carrying power and control currents according to the invention; Figure 3 is a diagram showing one manner in which the busbar may be connected; Figure 4 is a diagram showing a second method of connecting busbar; Figure 5 is a diagram showing a third method of connecting busbar; Figure 6 provides an example of a wiring arrangement involving use of a busbar in accordance with the invention. Figure 1 shows, in a manner which is not exhaustive, the principle whereby a busbar 1 is used as an example for understanding the present invention, it being borne in mind that all shapes and dimensions are possible. In order to aid improved comprehension of the device, the righthand termination of the busbar in Figure 1 shows the conductors detached and separated, conductors 2, 3 and 4 each being isolated from the others by the dielectric sheet material 5 offering a high level of electrical insulation. The external conductive layers 2 and 4 are covered in the same manner on their external surface by sheet material 5. Electrical conductors 2, 3 and 4 have different conductive cross-sections due to the different intensities of current they are called upon to carry. On the left-hand termination of the busbar shown in Figure 1, a branch connection 6, that is to say a conductive tongue, is shown, which is in electrical contact with the conductors 2, 3 and 4, through which electrical connection with another busbar or an electrical component is possible. It is possible to provide in this manner several branch connections for each conductor or to group such connections together within a single connector housing. Figure 2 shows an arrangement of conductors carrying power and conductors carrying control signals. The control conductors 7a and 7b are placed, in accordance with the arrangement shown in Figure 2, between the two power conductors 8 and 9. This arrangement is advantageous in that the control conductors are in this way placed within what amounts to a condenser formed by conductors 8 and 9, where they are protected from EMI/RFI. In figures 3, 4 and 5, three different forms of connection between two busbar or between a busbar and an electrical or electronic component are made explicit. Figure 3 shows three busbar 1a, 1b and 1c, of which a detailed perspective view is provided underneath. Each of the busbar has connection tongues 6, of which the widest should preferably be connected to power conductors and the narrowest to control conductors. Connectors 10 are fitted to tongue arrangements. Connectors 10 connect the tongues 6 to a current take-off wire, which is connected to another connector 10, which is mounted on another tongue arrangement 6 on another busbar. In this way, two busbar can be connected one to the other by means of the wires 11, in such a manner that the busbar may be disposed in any desired manner in relation to each other. The top part of Figure 4 provides a perspective view of a second method of interconnecting busbar. It can be seen in the figure that a number of conductive strips, narrower than the width of the busbar,leave the end terminations of the busbar and lead to connectors, to which they are attached. These connectors are arranged in housings manufactured in an electrically insulating material and which may be stacked in such a manner that different conductors in a busbar, separated one from another by insulating sheet material, may be connected to the connector. On the opposite face of the connector housing, conductive strips from the end termination of another busbar may also be fitted, or, as can be seen at the top of figure 4, branch connections may be provided. All include connectors which may be placed in stacked housings. Such connector arrangements are shown in the bottom half of figure 4 in plan and sectional views. Figure 5 shows a third method of interconnecting two busbar, in which laminated conductive strips leaving the end termination of a busbar may be used as contact blades and mounted in a connector housing, which may be plugged into a female socket connector unit on a conductor from a second busbar. The bottom half of figure 5 shows such an arrangement in sectional and plan views. Figure 6 shows, in diagrammatic form, a cabling arrangement with a busbar in which different connectors are connected and which possesses a multiplexing capability. In such connectors, CAN (Controller Area Network) multiplexing components are provided which may selectively transmit signals intended for specific components or send along the loop circuit signals deriving from sensors. The CAN components may then permit, when they are included in a connector, the implementation and use of so-called "smart" connectors allowing the CAN components to command and monitor the functions to be controlled.

Claims: A cabling arrangement for motorised vehicles and similar comprising: an electrical power supply system, a busbar (1) data transmission system to which component signals are addressed separately using a multiplexing process, the present arrangement having at least one busbar (1) with at least two power conductors (8, 9), providing electrical supply to components, and at least two control conductors (7a, 7b) used by the busbar data transmission system (1), all the conductors (7, 8, 9) being strips of metal separated one from another by insulating sheet material (5) and assembled into a laminated or "sandwich" structure, and each component or a second busbar (1b) taking off control and power supply current from the busbar using their respective connectors, characterized in that the control conductors (7a, 7b) are placed between two power conductors (8, 9). A cabling arrangement as described in claim 1, characterized in that the connection between the first busbar (1a) and the other secondary busbar (1b) takes the form of connectors possessing flexible wiring (11) in such a manner that the busbar (1a and 1b) may be disposed in any desired manner with respect to each other. A cabling arrangement as described in either claim 1 or claim 2, characterized in that the connection between the busbar takes the form of coupling components (12) linking the power conductors (2, 3) with the respective metal strips, which are electrically isolated one from the other. A cabling arrangement as described in either claim 1 or claim 2, characterized in that the connection between the busbar (1a, 1b, 1c) takes the form of plug/socket arrangements fitted or over-moulded to the power conductors. A cabling arrangement as described in any of the above claims, characterized in that the connector possesses a CAN functional unit. A cabling arrangement as described in any of the above claims, characterized in that the busbar is screwed or clipped to parts of the chassis of the motorised vehicles and adopts the shape of the relevant part of the chassis. A cabling arrangement as described in any of the above claims, characterized in that the busbar (1) is mounted predominantly in or under the roof of the motorised vehicle. A cabling arrangement as described in any of the above claims 1 to 6, characterized in that the busbar (1) is mounted along the central longitudinal axis in the area of the chassis bed.

Inventors: CHEVASSUS-MORE ALAIN, PERNOT CHRISTIAN, CHEVASSUS-MORE, ALAIN, PERNOT, CHRISTIAN
Applicants: FRAMATOME CONNECTORS INT, FCI
Application year: 1999
Main classification: B60R16
IPC codes: H01B7, H01R9, B60R16