EP1958307A1

EP1958307A1 - An electric cable connection assembly and a method for connecting an earth connection cable to a vehicle component

Info

Publication number: EP1958307A1
Application number: EP05812693A
Authority: EP
Inventors: Robert Johansson; Peter Olsson
Original assignee: Volvo Lastvagnar AB
Current assignee: Volvo Truck Corp
Priority date: 2005-12-01
Filing date: 2005-12-01
Publication date: 2008-08-20
Also published as: WO2007064268A1; EP1958307A4

Abstract

The present invention concerns an electric cable connection assembly for fixing and electrically connecting an electric cable to a vehicle component, in particular an earth connection cable (1) to an engine (3) mounted in a vehicle, comprising a first clamping element (5) with a first connection surface (7) and a second clamping element (6) with a second connection surface (8), wherein said first clamping element (5) is provided on a vehicle component (3) and said second clamping element (6) is provided on a mounting bracket (2) adapted for receiving the vehicle component (3), and in that said first and second connection surfaces (7, 8) are adapted for fixing and electrically connecting a cable end (10) to the vehicle component (3) when said vehicle component is positioned on the mounting bracket (2) so that the clamping elements (5, 6) bear on each other. By the invention, a reliable electric cable connection is provided, whiph is easy to mount and ensures a vibration free connection of e.g. an earth connection cable end to the engine block of a vehicle.

Description

AN ELECTRIC CABLE CONNECTION ASSEMBLY AND A METHOD FOR CONNECTING AN EARTH CONNECTION CABLE TO A VEHICLE COMPONENT

The present invention relates to an electric cable connection assembly for fixing and electrically connecting an electric cable to a vehicle component, in particular an earth connection cable to an engine mounted in a vehicle, said assembly comprising a first clamping element for fitting onto a second clamping element for clamping the electric cable therebetween, said first and second clamping elements being provided with corresponding first and second connection surfaces cooperating for fixing and connecting the electric cable to the vehicle component.

For establishing electrical contact between components in a vehicle, electric cables are provided with cable terminals at the cable ends. Typically, such cable terminals comprise a cable shoe e.g. shaped as a ring or fork or the like which is fastened to the relevant component by a bolt. In this way, a relative easy and reliable connection may be provided that ensures a good electrical contact with a very low voltage drop. In particular in relation to providing earth connection, such as an earth connection to the vehicle engine which is mounted on rubber suspended mounting brackets, it is important to establish a good electrical contact to ensure a very low voltage drop. In heavy vehicles, such as trucks, busses, construction equipments, and the like, and also in boats and ships, where high currents are used for e.g. the starter engine, the electric cables are often relatively thick and thus relatively stiff. This puts an extra stress on the electrical connection, especially since e.g. the engine vibrations are much higher than on e.g. a passenger car with a small engine.

However in some instances even this electrical connection may prove cumbersome and time consuming in the vehicle production, and therefore it is an object of the present invention to provide a quick and reliable mounting of the electrical connection, in particular it is an object of the invention to provide a quick and reliable earth connection which is suitable for providing earth connection to a vehicle engine in a heavy vehicle such as a truck. These objects are achieved by a connection assembly of the initially mentioned kind wherein said first clamping element is provided on a vehicle component, said second clamping element is provided on a mounting bracket for receiving the vehicle component adjacent the first clamping element, where a cable end is clamped between the clamping elements.

According to another aspect of the invention, there is provided a method for fixing and connecting an earth connection cable to an engine in a vehicle, where the cable end is clamped between a first and second clamping element, where said first clamping element is provided on a vehicle component, and said second clamping element is provided on a mounting bracket for receiving the vehicle component, and where the vehicle component is lowered onto the mounting bracket for clamping the cable end therebetween.

By the invention, a reliable electric cable connection is provided, which is easy to mount as no tooling is required for clamping the cable end to the engine block. In particular for engines in a heavy vehicle, such as a truck engine, the weight of the engine will instantly clamp the cable end and thereby retain the cable between the engine and the engine mounting bracket. Compared with the traditional technique of fixing an electric cable, such as an earth connection, the connection assembly according to the invention is advantageous as it is ensured by the present invention that no vibration between the cable end and the engine will occur when the cable is mounted in the connection assembly according to the invention. Hereby, the endurance and robustness of the earth connection is considerably improved.

The assembly of the connection according to the invention during the fitting of an engine in a vehicle, e.g. during the manufacture of a truck, is quick and simple, and accordingly, the method of fastening an earth connection according to the invention is less time consuming whereby valuable production time is reduced just as the quality is improved. Preferably, the electrically conductive cable is provided with a substantially cylindrical end section member on the cable end to be clamped. In particular the end section member is preferably made of copper. Hereby, there is ensured a good electrical contact between the clamping elements and the cable end to be clamped. In particular if the end section is made of a soft electrically conductive metal, such as copper, a good surface contact may be achieved as the surface of the end section is formed by the surfaces of the channels. This results in both a good electrical contact and a firm grip of the cable end. Accordingly, the first and second channels are preferably provided with grooves extending generally perpendicular to the longitudinal axis of the channels. Hereby, the retention of the cable is further enhanced.

Preferably, the first and second channels are provided with a half-circular cross- section, and accordingly, the first and second channels together preferably form a substantially cylindrical opening. However, it is by the invention realised that other geometric shapes may be used. Preferably, the first and second channels together form a blind hole.

Preferably, a clamping device is provided on the engine mounting bracket adjacent the second channel for fixing a cable section adjacent the cable end thereto. Hereby, the cable end is relieved from any tension or bending stress that could otherwise weaken the cable in the connection assembly.

In other to establish an earth connection by a connection assembly according to the invention, at least the engine block is made in an electrically conductive metal.

The invention is described in more detail in the following with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a preferred embodiment of a connection assembly according to the invention, Fig. 2 is a detail view thereof, and Fig. 3 is a schematic cross-section view of the connection assembly according to the invention.

In the figures are shown an engine mounting bracket 2, which is mounted to a vehicle chassis frame 4 via one or more rubber suspension mounting elements 12 (see figure 3). The mounting bracket 2 is provided with a mounting member 6, which is adapted to receive a corresponding mounting member 5 of the engine block 3. The mounting members 5, 6 are provided with channels 7, 8 for receiving the cable end 10 of an electric cable 1, whereby the mounting members 5, 6 function as first and second clamping elements. In this example, an earth cable connected to an engine mounted to an engine mounting bracket is used as an example. However, other vehicle components that require a cable connection may be used in the same way. Preferably, the vehicle component should be relatively heavy in order to clamp the cable between itself and a mounting surface or mounting bracket. By using a heavy component, the cable is held in place until the component is fixed to the mounting bracket with a fastening means, such as a screw.

The first and second channels 7, 8 in the first and second clamping elements 5, 6 are formed with a half-circular cross-sectional shape so that when the clamping elements 5, 6 abut each other so that they bear on each other, the two channels 7, 8 together form a cylindrical channel which is slightly smaller in diameter than the cable end diameter. This causes a clamping action to take place. Preferably, the channels 7, 8 are provided with grooves 11 (see fig. 2), which preferably are oriented generally perpendicular to the longitudinal axis of the channels 7, 8.

The cable 1 is provided with a terminating end sleeve at the cable end 10. This sleeve is preferably made in copper or similar relatively soft and electrically conductive metal or metal alloy, so as to ensure a firm fixation of the cable end 10 between the clamping elements 5, 6 as the geometry of the channels and in particular the grooves therein will deform the sleeve. This will also ensure a good electrical contact with a very low voltage drop in the cable connection assembly. The terminating end sleeve will also ensure that no strands of the electric cable are loose and may be squeezed between the clamping elements outside of the channels.

The cable 1 is fixed to the mounting member 6 by a clamping device 9 positioned adjacent the inlet of the channel 8 (see figures 1 and 2). By fixing the cable 1 to the mounting element 6 at a position just before the cable end 10, it is ensured that the cable connection is stress relieved and not subjected to tension or bending forces just as vibrations between the engine and the cable connection are eliminated. This fixing also holds the cable end in position which simplifies the mounting of the engine. Since the engine mounting brackets and the cable are mounted at one station in the production plant, and the engine is mounted at a later stage, it is important that the cable is in the right position when the engine is mounted.

The method of establishing an earth connection by a connection assembly according to the invention is particular advantageous as one of the engine mounting members 2 which are provided in the vehicle frame 4 are provided with a cable receiving channel 8 in which the cable end 10 is positioned, as shown in figure 1. The engine 3 (not shown in fig. 1) is mounted by positioning the mounting member 5 thereof (see fig. 3) on the top of the receiving mounting members 6 of the mounting bracket 2 of the frame 4. In particular by heavy vehicles, such as trucks, the weight of the engine will cause the clamping action around the cable end to take place and thereby a firm grip around the cable end 10 of the cable 1 is established. After the mounting of the engine, the engine is also fixed to the mounting brackets with bolts (not shown).

The assembly of the connection according to the invention is integrated in the operation of fitting the engine in a vehicle, e.g. during the manufacture of a truck. Accordingly, the method of fastening an earth connection according to the invention is less time consuming whereby valuable production time is reduced just as the quality is improved.

Above the invention is described with reference to a preferred embodiment. However, it is realised that other embodiments may be provided without departing from the scope of the invention as defined by the accompanying claims. For instance the geometric shape of the clamping channels may be any suitable shape. The resulting channel of the two clamping elements could be a blind hole or a through- going hole, just as the hole may be tapered, cylindrical or any other suitable shape.

Claims

PATENT CLAIMS:

1. An electric cable connection assembly for fixing and electrically connecting an electric cable to a vehicle component, in particular an earth connection cable (1) to an engine (3) mounted in a vehicle, comprising a first clamping element (5) with a first connection surface (7) and a second clamping element (6) with a second connection surface (8), characterised in that said first clamping element (5) is provided on a vehicle component (3) and said second clamping element (6) is provided on a mounting bracket (2) adapted for receiving the vehicle component (3), and in that said first and second connection surfaces (7, 8) are adapted for fixing and electrically connecting a cable end (10) to the vehicle component (3) when said vehicle component is positioned on the mounting bracket (2) so that the clamping elements (5, 6) bear on each other.

2. An electric cable connection assembly according to claim 1, wherein said first and second connection surfaces (7, 8) are adapted for fixing and electrically connecting the cable end (10) to the vehicle component (3) by the weight of the vehicle component when the clamping elements (5, 6) bear on each other.

3. An electric cable connection assembly according to claim 1 or 2, wherein said vehicle component (3) is an engine block.

4. An electric cable connection assembly according to any of claims 1 to 3, wherein said first connection surface (7) constitute a channel in said first clamping element

(5) and said second connection surface (8) constitute a channel in said second clamping element (6).

5. An electric cable connection assembly according to claim 4, wherein the first and second channels (7, 8) are provided with a half-circular cross-section.

6. An electric cable connection assembly according to claim 4 or 5, wherein the first and second channels (7, 8) together form a substantially cylindrical opening.

7. An electric cable connection assembly according to any of claims 4 to 6, wherein the first and second channels (7, 8) are provided with grooves (11) extending generally perpendicular to the longitudinal axis of the channels (7, 8).

8. An electric cable connection assembly according to any of claims 4 to 7, wherein the first and second channels (7, 8) together form a blind hole.

9. An electric cable connection assembly according to any of claims 1 to 8, wherein said first and second connection surfaces (7, 8) are adapted for receiving the cable end (10) together with a mounted protection sleeve.

10. An electric cable connection assembly according to any of claims 1 to 9, wherein a clamping device (9) is provided on the mounting bracket (2) adjacent the second connection surface (8) for fixing a cable section adjacent the cable end (10) of the cable (1) thereto.

11. A method for fixing and electrically connecting an electric cable to a vehicle component, comprising the steps of:

- placing a cable end (10) on a second clamping element (6) provided on a mounting bracket (2),

- lowering the vehicle component (3) with a first clamping element (5) onto the second clamping element (6) so that the clamping elements (5, 6) bear on each other, thereby clamping the cable end (10) between a first and second connection surface (7, 8) provided on the first and second clamping element (5, 6).