Automotive communications cable

An automotive communications cable includes a cable jacket, a pair of twisted conductors disposed within the cable jacket, and two or more insulating strands disposed within the cable jacket. The two or more insulating strands include a central insulating strand disposed between a first conductor in the pair of twisted conductors and a second conductor in the pair of twisted conductors.

TECHNICAL FIELD

This specification relates to automotive communications cables.

BACKGROUND

Modern vehicles have dozens of electronic control units (ECUs) that obtain sensor data, process the sensor data to generate output signals, and provide the output signals to particular vehicle components that perform actions based on the output signals. For example, a transmission control unit can obtain engine speed data, vehicle speed data, and throttle position data and generate an output signal that defines a desired gear for a vehicle. If the vehicle is not in the desired gear, the transmission can shift to the desired gear in response to the output signal.

Semi-autonomous and autonomous vehicles generally have an even greater number of ECUs than human-operated vehicles because sensor inputs replace some or all human inputs, and those additional sensor inputs must be processed. Moreover, semi-autonomous and autonomous vehicles often include redundant systems in order to satisfy safety requirements.

Generally, each ECU in a vehicle is connected to a central communications network over which the ECUs can exchange data with each other, with external sensors, and with other components of the vehicle. The central communications network includes a number of communications cables that are costly to manufacture and add significant weight to the vehicle. The communications cables in vehicles are generally jacketed unshielded twisted pairs (JUTPs).

SUMMARY

This specification describes an improved communications cable. The communications cable includes a pair of twisted conductors disposed within a cable jacket. Two or more insulating strands are also disposed within the cable jacket. The two or more insulating strands include a central insulating strand disposed between a first conductor in the pair of twisted conductors and a second conductor in the pair of twisted conductors.

The subject matter described in this specification can be implemented in particular embodiments so as to realize one or more of the following advantages. First, the improved communications cable weighs less than a conventional JUTP of the same wire gauge. This is because the lack of an individual insulator for each conductor allows the cable jacket to have a smaller diameter, which reduces the weight of the communications cable due to the cable jacket.

The improved communications cable is cheaper and easier to manufacture than a conventional JUTP because the conductors in the improved communications cable do not have their own insulator. Instead, the improved communications cable has insulating strands that can be extruded at the same time using the same extrusion process, which further simplifies the manufacturing process.

The use of separate insulating strands also provides flexibility in adjusting the relative permittivity of the cable, since the size and material composition of each insulating strand can be adjusted, as necessary.

Finally, the improved communications cable can also be stripped more easily than a conventional JUTP, i.e., by removing the cable jacket and the exterior insulating strands in one stripping process. The central insulating strand holds the conductors in a fixed position, allowing defined insertion into a connector through laser welding or crimping. Additionally, the central insulating strand helps to maintain the twist in the communications cable for the entire length of the cable. This increases noise immunity.

DETAILED DESCRIPTION

In the drawings, specific arrangements or orderings of schematic elements, such as those representing devices, modules, instruction blocks and data elements, are shown for ease of description. However, it should be understood by those skilled in the art that the specific ordering or arrangement of the schematic elements in the drawings is not meant to imply that a particular order or sequence of processing, or separation of processes, is required. Further, the inclusion of a schematic element in a drawing is not meant to imply that such element is required in all embodiments or that the features represented by such element may not be included in or combined with other elements in some embodiments.

Several features are described hereafter that can each be used independently of one another or with any combination of other features. However, any individual feature may not address any of the problems discussed above or might only address one of the problems discussed above. Some of the problems discussed above might not be fully addressed by any of the features described herein. Although headings are provided, information related to a particular heading, but not found in the section having that heading, may also be found elsewhere in the specification.

FIG. 1Ais a diagram of a cross-section of a conventional JUTP. The conventional JUTP has a cable jacket110. Two conductors120, each surrounded by insulators130, are disposed within the cable jacket110.

FIG. 1Bis a diagram of a cross-section of an improved communications cable. The communications cable includes a cable jacket140, five insulating strands150, and two conductors120that are identical to the conductors120inFIG. 1A.

The cable jacket140provides mechanical support to the communications cable and electrically insulates the conductors120from the environment. The cable jacket140is generally a hollow cylinder and can be made of any appropriate electrical insulator, e.g., any appropriate plastic or rubber material that has enough flexibility to allow insertion into a vehicle.

The conductors120are fully disposed within the cable jacket140. The conductors120can be any appropriate electrical conductors. For example, the conductors120can be copper Litz wire, which is made of wound strands of copper wire. Alternatively, the conductors120can be solid conductors, e.g., single pieces of copper.

The insulating strands150are fully disposed within the cable jacket140and are generally cylindrical in shape. A central insulating strand disposed between the two conductors120separates them from each other. The insulating strands150can be made of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), or any other suitable material. The use of separate insulating strands provides flexibility in adjusting the relative permittivity of the cable, since the size and material composition of each insulating strand can be adjusted, as necessary. The improved communications cable has a smaller diameter than a conventional JUTP, which reduces its weight and intrinsic impedance.

FIG. 2is a diagram of a side view of the improved communications cable described in reference toFIG. 1B.FIG. 2depicts the communications cable without the cable jacket140.

For simplicity,FIG. 2depicts an untwisted implementation of the improved communications cable described in reference toFIG. 1B. In some implementations, however, the conductors120are twisted about each other. Twisting the conductors120reduces the amount of electromagnetic radiation that the communications cable generates and improves rejection of external electromagnetic interference.

FIG. 3Ais a flow chart of an example process300for stripping the improved communications cable described in reference toFIG. 1B. The process can be performed by a person or by an automated machine that is configured to do so. For convenience, the process will be described as being performed by a person.

Using conventional wire strippers, a person exposes the conductors by stripping the cable jacket and the four exterior insulating strands away from the conductors in one stripping process (310). This is not possible with a conventional JUTP, in which each conductor additionally has its own insulator that must be separately stripped.FIG. 3Bis a diagram of a cross-section of a stripped version of the improved communications cable described in reference toFIG. 1B.

The person attaches the exposed conductors to a connector, e.g., by crimping, laser welding, or soldering the conductors to the connector (320). This is possible because the central insulating strand holds the conductors in place relative to each other. In contrast, after a person strips a conventional JUTP, the conductors are able to move relative to each other, which makes the above-mentioned attachment methods more difficult. Additionally, the central insulating strand helps to maintain the twist in the communications cable for the entire length of the cable. This increases noise immunity.

FIG. 4is a flow chart of an example process400for manufacturing the improved communications cable described in reference toFIG. 1B. For convenience, the process will be described as being performed by an automated system of one or more machines and one or more computers.

The system extrudes each of the five insulating strands in one simple, standard process (410). The system twists the insulating strands with two conductors to form an assembly (420). The system twists the assembly while it is still hot from the extrusion process and then fixes the assembly in the twisted position (430). Fixing the assembly can involve cooling the assembly. Finally, the system extrudes a cable jacket on the assembly (440).

The process400requires fewer extrusions than the manufacturing process for a conventional JUTP because the manufacturing process for a conventional JUTP includes extruding insulators on each conductor. The improved communications cable does not have separate insulators for each conductor but instead strands that can be extruded at the same time using the same extrusion process, which further simplifies the manufacturing process.

While logic flows or operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various software components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described software components can generally be integrated together in a single software program or multiple software programs.

In some instances, functions in claims will be preceded with the phrase “one or more.” The phrase “one or more” as used herein includes a function being performed by one element, a function being performed by more than one element, e.g., in a distributed fashion, several functions being performed by one element, several functions being performed by several elements, or any combination of the above.

In some instances, claim elements will be preceded with the terms first, second, third and so forth. It should be understood that, although the terms first, second, third, etc. are, in some instances, used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first contact could be termed a second contact, and, similarly, a second contact could be termed a first contact, without departing from the scope of the various described embodiments. The first contact and the second contact are both contacts, but they are not the same contact.

Some aspects of the subject matter of this specification may include gathering and use of data available from various sources. The present disclosure contemplates that in some instances, this gathered data may identify a particular location or an address based on device usage. Such personal information data can include location-based data, addresses, subscriber account identifiers, or other identifying information. The present disclosure further contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure.