FLAT RIBBON CABLES AND MANUFACTURING PROCEDURES

Abstract

The present invention relates to a flat ribbon cable (1) comprising a ribbon-shaped insulating body (2) oriented along a longitudinal direction (X), electrical conductors (4) arranged within the insulating body (2), at least one separate cavity (6), and at least one optical conductor (10) arranged in the cavity (6), wherein a first diameter (D1) of the cavity (6) is variable, such that in a first state the first diameter (D1) is larger than a second diameter (D2) of the optical conductor (10) and the optical conductor (10) is displaceable in the cavity (6) relative to the insulating body (2), and in a second state the first diameter (D1) of the cavity (6) corresponds in at least a second and / or third direction (Y, Z) to the second diameter (D2) of the optical conductor (10) and the optical conductor (10) is fixed in the cavity (6).The present invention further relates to a manufacturing process.

Description

Technical field

[0001] The invention relates to a flat ribbon cable for optical signal transmission and electrical current and / or signal transmission, as well as a manufacturing method for such a flat ribbon cable, in particular for use in the automotive sector. State of the art

[0002] Flat ribbon cables, especially flexible flat cables (FFCs), are experiencing increasing interest in the automotive sector. Their flexible properties allow them to conform well to the contours of a vehicle, thus saving space during installation. With increasing data rates, optical conductors are being used alongside electrical conductors for (power and / or) data transmission. This leads to a scenario, particularly in the automotive industry, where high data transmission rates are required via the wiring while simultaneously ensuring a power supply. However, the flexibility of flat ribbon cables means they cannot be laid in a defined shape, which complicates manual or automated processing.

[0003] In the prior art, round so-called hybrid cables are known, containing a proportion of metallic conductors (e.g., copper) and a proportion of optical conductors. In these round hybrid cables, in addition to individual metallic conductors, there are tubes into which an optical conductor, e.g., a fiber optic cable, can be blown.

[0004] However, the round hybrid cables of the state of the art have at least the disadvantages that conventional round cables require more installation space, fiber optic cables are very sensitive to kinking and tensile stresses and must be protected with considerable effort, fiber optic cables are therefore guided in a rigid tube, whereby a fiber optic cable (when bent) lies against the inner radius, which, depending on the bending radius, creates a protrusion at the cable ends, leading to an increased deviation from the zero fiber, so that an (unintentional) undercutting of the minimum bending radius is possible in the rigid tube, so that the fiber optic cable can be damaged when bending. Description of the invention

[0005] It is therefore an object of the present invention to provide a cable that is suitable for the transmission of power and high data rates, and that can be manufactured simply and flexibly and, preferably in a vehicle, laid simply and in a space-saving manner.

[0006] The aforementioned problem is solved by a flat ribbon cable according to claim 1 and a manufacturing method according to claim 7. Further advantageous embodiments of the invention can be found in the dependent claims, the description, and the drawings.

[0007] In particular, the above-mentioned problem is solved by a flat ribbon cable comprising a ribbon-shaped insulating body oriented in a first plane along a longitudinal direction, electrical conductors for electrical current and / or signal transmission arranged within the insulating body and extending in the longitudinal direction, at least one separate cavity formed alongside the electrical conductors in the insulating body and extending in the longitudinal direction, and at least one optical conductor for optical signal transmission arranged in the cavity and extending longitudinally through the cavity, wherein a first diameter of the cavity is variable such that the first diameter is larger than a second diameter of the optical conductor in a first state and the optical conductor is displaceable within the cavity relative to the insulating body.and the first diameter of the cavity in a second state corresponds in at least a second and / or third direction to the second diameter of the optical conductor, and the optical conductor is fixed in the cavity.

[0008] In the present flat ribbon cable, the at least one cavity is a flexible cavity that can change its size, diameter, or volume. This distinguishes it from the rigid tubing used in prior art. The present flat ribbon cable can simultaneously transmit power via electrical conductors and high-speed data transmission via the at least one optical conductor. Due to the flexible cavity in the present flat ribbon cable, the at least one optical conductor can be inserted into the cavity as needed, in the desired dimensions and quantity. This allows for flexible manufacturing of the flat ribbon cable. Furthermore, the at least one optical conductor can be pre-assembled, so that its assembly can be performed independently of the manufacturing or assembly of the flat ribbon cable.This also makes the production of the ribbon cable more flexible than in the prior art, where assembly only takes place after the optical conductor has been inserted into the round hybrid cable, which complicates handling. The flexible cavity also makes it possible to insert at least one optical conductor of variable length, and preferably significantly longer than the ribbon cable itself, into the cavity. This allows the insulation body to absorb any tensile stresses, for example, when bending the ribbon cable, thus preventing damage to the optical conductor. Furthermore, this ribbon cable allows all the advantages of a flexible ribbon cable regarding the automation of assembly to be utilized for an optical cable as well. And regarding...The advantage of the flat ribbon cable is that lower requirements can be placed on the high-frequency design of the flat ribbon cable, since high data rates can be transmitted via the optical conductor.

[0009] Preferably, the first diameter in the first state is at least twice, and preferably four times, the size of the second diameter. Because the first diameter of the cavity is significantly larger than the second diameter of the optical conductor, the optical conductor can be guided through the cavity easily and reliably. Furthermore, it is possible to arrange multiple optical conductors in parallel within the cavity. In particular, the optical conductor can have different (second) diameter sizes, for example, if the optical conductor is already assembled, whereby the assembled optical conductor still fits completely through the cavity because the cavity has a significantly larger (first) diameter.

[0010] Preferably, a first length of the optical conductor along its central axis corresponds to at least 1.1 times, more preferably at least 1.5 times, and most preferably at least 2 times, a second length of the cavity it traverses. The optical conductor has a greater length than the cavity or the ribbon cable. This greater length provides strain relief for the optical conductor, so that bending (within the predetermined bending radius) of the ribbon cable is harmless to the optical conductor.

[0011] Preferably, the optical conductor is arranged in a meandering shape, at least in sections, within the cavity. This meandering shape allows the optical conductor to be accommodated within the cavity with its excess length. The optical conductor has a significant excess length (and thus strain relief) without protruding substantially beyond the cavity at either end. The meandering shape protects the optical conductor with its excess length within the cavity.

[0012] Preferably, the insulating body comprises an elastic material, at least in the cavity area, so that the optical conductor is clamped by the cavity in its second state. "Clamped by the cavity" here means clamped by the cavity wall. Since the insulating body is made of an elastic material, the cavity retracts to its original state after the tensile force ceases, for example, when the compressed air supply to the cavity is discontinued. This retraction exerts a clamping force on the optical conductor, which securely fixes the optical conductor within the cavity.

[0013] Preferably, the optical conductor is pre-assembled and, in the initial state of the cavity, is fully displaceable within the cavity relative to the insulating body. A pre-assembled optical conductor has a connection element, preferably a ceramic ferrule, at at least one end. The fact that the (pre-)assembled optical conductor is fully displaceable within the cavity means that the optical conductor, together with the connection element, is displaceable within the cavity. The design with the (pre-)assembled optical conductor has the advantage that the optical conductor can be precisely pre-assembled at another location and then easily inserted into the existing ribbon cable. This increases overall precision and ensures a simple assembly of the ribbon cable.

[0014] The above-mentioned problem is further solved in particular by a manufacturing process for a flat ribbon cable, wherein the flat ribbon cable comprises at least a ribbon-shaped insulating body, electrical conductors in the insulating body, at least one separate cavity, and at least one optical conductor arranged in the cavity, wherein the process comprises at least the following steps: providing the insulating body extending along a first longitudinal direction, pressurizing the cavity with a liquid or gaseous medium so that the volume of the cavity increases to a first state, inserting the optical conductor into the cavity, at least until the optical conductor extends over the entire length of the cavity, and ceasing to pressurize the cavity with the medium.so that the cavity reduces its volume to a second state and fixes the optical conductor in the cavity.

[0015] The present method makes it possible to easily arrange at least one optical conductor as needed within a ribbon cable. In particular, several optical conductors can be arranged simultaneously or sequentially within the cavity(s). By pressurizing the cavity with a medium, the ribbon cable acquires a defined shape or geometry, at least temporarily. This defined geometry simplifies the insertion of the optical conductor and also facilitates manual or automated further processing of the ribbon cable. Once the optical conductor(s) have been inserted, and the pressurization with the medium is discontinued, the cavity returns to its compressed state. The ribbon cable remains compact, the optical conductors are fixed and more resistant to vibrations, and the ribbon cable regains its flexible properties.

[0016] Preferably, the optical conductor inserted into the cavity comprises a pre-assembled optical conductor. The pre-assembled optical conductor includes at least one connection element at at least one end. This connection element serves to connect the optical conductor to a further device for transmitting optical signals. The connection element is preferably permanently bonded to the optical conductor. The connection between the connection element and the optical conductor can be made separately during the fabrication of the present ribbon cable. This allows for a high-precision connection and results in excellent signal transmission characteristics.

[0017] Preferably, the insertion of the optical conductor involves pushing or inserting the optical conductor into or through the cavity. This insertion or insertion of the optical conductor is a simple process and can be performed flexibly, either directly during the production of the ribbon cable or at a later time.

[0018] The following description of embodiments is given with reference to the accompanying figures. These show: Fig. 1 an embodiment of a manufacturing process for a flat ribbon cable in the provisioning step; Fig. 2 the embodiment of the manufacturing process from Fig. 1 in the step of pressurizing the cavity with a medium under pressure; Fig. 3 the embodiment of the manufacturing process Fig. 2 in the step of inserting the optical conductor into the cavity; and Fig. 4 the embodiment of the manufacturing process from Fig. 3 in the step of ending the actuation, and simultaneously an embodiment of the finished product.

[0019] Preferred embodiments are described in detail below with reference to the accompanying figures.

[0020] Fig. Figure 1 shows an embodiment of a ribbon cable 1 with an optical conductor 10, which is yet to be integrated into the ribbon cable 1. The ribbon cable 1 has a ribbon-shaped, flexible insulating body 2, which is aligned in a first plane XY along a longitudinal direction X. Alignment in a first plane XY simplifies the integration of the optical conductor 10 into the ribbon cable 1. Due to the flexible, pliable properties of the ribbon cable 1, it can later be adapted to a contour, for example, routed along a vehicle body. The illustrated ribbon cable 1 also has electrical conductors 4 for electrical current and / or signal transmission. The electrical conductors 4 comprise at least one electrical conductor 4. The electrical conductors 4 are arranged within the insulating body 2 and extend in the illustrated Fig. 1 - 4 in the longitudinal direction X.

[0021] In addition, the illustrated flat ribbon cable 1 has at least one separate cavity 6. The cavity is formed next to the electrical conductors 4 in the insulating body 2 and extends in the longitudinal direction X. The term 'next to' means that the at least one cavity 6 is formed at any point on the insulating body 2 and does not cross at least the electrical conductors 4.

[0022] Furthermore, the flat ribbon cable 1 comprises at least one optical conductor 10 for optical signal transmission. Preferably, the optical conductor 10 comprises an optical fiber. In the finished state of the flat ribbon cable 1, the optical conductor 10 is arranged in the cavity 6 and extends through the cavity 6 in the longitudinal direction X with a first length L1. The first length L1 of the optical conductor 10 along its central axis M corresponds in particular to at least 1.1 times, preferably at least 1.5 times, and most preferably at least 2 times a second length L2 of the cavity 6 traversed. The optical conductor 10 is arranged in a meandering pattern, at least in sections, within the cavity 6 (see figure). Fig. 4).

[0023] In Fig. In Figure 1, the optical conductor 10 is provided outside the ribbon cable 1. The illustrated optical conductor 10 is already (pre-)assembled and has a connection element 12. The connection element 12 serves to connect the optical conductor 10 to another device for transmitting optical signals, such as another cable, a PCB connector, or another connector for transmitting optical signals. The connection element 12 preferably comprises a ceramic ferrule through which optical signals can be transmitted to a connected complementary connection element. The connection element 12 can have a larger (second) diameter (D2) than the optical conductor 10 itself, at least in some areas. In alternative embodiments, the connection element 12 can be configured to connect to several optical conductors 10 (orto be connected to optical fibers), which significantly increases the size of the connection element 12 compared to the (second) diameter of a single optical conductor 10, while the connection element 12 can still be inserted through the cavity 6.

[0024] In comparison of the Fig. Figures 1-4 show that the cavity 6, with its first diameter D1, is flexible or changeable. In a basic state of the cavity 6, the first diameter D1 is essentially zero; that is, with an elastic material of the insulating body 2, at least in region 2a of the cavity 6, the cavity 6 is minimally to completely closed by the contracted wall of the cavity 6 (see Figure 1-4). Fig. 1) With a less elastic or even non-elastic material, the wall of the cavity 2 would collapse loosely in the ground state. In a first state, the first diameter D1 is larger than a second diameter D2 of the optical conductor 10. The first diameter D1 in the first state preferably corresponds to at least twice, and preferably four times, the second diameter D2. The second diameter D2 includes both the diameter of the optical conductor 10 itself and the (outer) diameter of an (optionally) connected connecting element 12 (see figure). Fig. 2) Because the first diameter D1 is (significantly) larger than the second diameter D2, the optical conductor 10 (optionally including the connecting element 12) can be moved within the cavity 6 relative to the insulating body 2. The optical conductor 10 can be inserted into the cavity 6 without touching the (inner) wall of the cavity 6 (see figure). Fig. 3) The non-contact design simplifies insertion and prevents damage to the optical conductor 10 during insertion. Once the optical conductor 10 is fully inserted, i.e., from one end of the cavity 6 to the other end, the first diameter D1 can be adjusted so that, in a second state, the first diameter D1 of the cavity 6 corresponds in at least a second and / or third direction Y, Z to the second diameter D2 of the optical conductor 10 (without the optional connection element 12), and (only) the optical conductor 10 (without the optional connection element 12) is fixed in the cavity 6 (see Figure 1). Fig. 4) The second state essentially corresponds to the basic state of the cavity 6, except that in the second state the optical conductor 10 is arranged in the cavity 6, and the cavity 6 can contract minimally to the size of the optical conductor 10. Since the insulating body 2 preferably has an elastic material at least in region 2a of the cavity 6, the optical conductor 10 is clamped by the cavity 6 in the second state of the cavity 6.

[0025] A preferred embodiment of a manufacturing method for a flat ribbon cable 1 is described below, wherein the flat ribbon cable 1 comprises at least one ribbon-shaped insulating body 2, electrical conductors 4 within the insulating body 2, at least one separate cavity 6, and at least one optical conductor 10 arranged within the cavity 6. The method comprises at least the following steps: providing the insulating body 2, which extends along a first longitudinal direction X, and pressurizing the cavity 6 with a liquid or gaseous medium so that the volume of the cavity 6 increases to a first state. The optical conductor 10 is then inserted into the cavity 6, at least until the optical conductor 10 extends over the entire length of the cavity 6.And finally, stopping the pressure on the cavity 6 with the pressurized medium, so that the cavity 6 reduces its volume to a second state and fixes the optical conductor 10 in the cavity 6.

[0026] With reference to Fig.In steps 1-4, the ribbon cable 1 and the optical conductor 10 are initially provided in a first plane XY. The optical conductor 10, which is to be inserted into the cavity 6, comprises a pre-assembled optical conductor 10 with a connection element 12. A connection element 12 can be arranged at each end of the optical conductor 10. The optical conductor 10 is preferably gripped and fixed (automatically) by a gripping device 14. The ribbon cable 1 can also be fixed by a stationary or movable fixing device. The optical conductor 10 can be supplied to the ribbon cable 1, or vice versa, via the gripping device 14 and / or the fixing device. At least the area 2a of the cavity 6 is not gripped directly, as the cavity 6 varies in size or volume. The cavity 6 is initially in its basic state.Preferably with the aid of a nozzle inserted into an opening in the cavity 6, a pressurized medium, preferably compressed air, is introduced into the cavity 6, causing the first diameter D1 in the cavity 6 to increase. When the first diameter D1 in the cavity has reached a predetermined size, the compressed air is preferably kept at a constant level so that the first diameter D1 does not change. From this point on, the (pre-assembled) optical conductor 10 can be inserted into or through the cavity 6 by pushing or sliding the optical conductor 10 through it. For insertion along a thrust direction S, the gripping device 14 with the fixed optical conductor 10 can be inserted at least partially into the cavity 6. If a longer optical conductor 10 is inserted with some pressure or...When the optical conductor 10 is inserted into the cavity 6 at the stop on the opposite side of the cavity 6, it preferably forms a meandering shape within the cavity 6, i.e., the optical conductor 10 winds its way through the cavity 6 in the first plane XY along the first direction X. When the optical conductor 10 protrudes from the cavity 6 at both ends, preferably including the connecting element 12, the optical conductor 10 is completely located within the cavity 6 or extends over the entire cavity 6. From this point on, the compressed air can be released from the cavity 6. This is most easily achieved by ceasing to pressurize the cavity 6 with the medium or compressed air. As a result, the cavity 6 reduces its volume to a second state and fixes the optical conductor 10 within the cavity 6.The flat ribbon cable 1, which can then transmit both electrical current and / or electrical signals via the electrical conductors 4 as well as optical signals via the optical conductor 10, is then completely manufactured. REFERENCE MARK LIST 1 flat ribbon cable 2 insulating bodies 2a Area of ​​the cavity 4 electrical conductors 6 Cavity 10 optical ladder 12 Connection element 14 Gripping device D1 first diameter D2 second diameter L1 first length L2 second length M Central axis S thrust direction X Longitudinal direction XY first level Y second direction Z third direction

Claims

Flat ribbon cable (1) comprising: a) a ribbon-shaped insulating body (2) aligned in a first plane (XY) along a longitudinal direction (X); b) electrical conductors (4) for electrical current and / or signal transmission, arranged within the insulating body (2) and extending in the longitudinal direction (X); c) at least one separate cavity (6) formed alongside the electrical conductors (4) in the insulating body (2) and extending in the longitudinal direction (X); and d) at least one optical conductor (10) for optical signal transmission, arranged in the cavity (6) and extending through the cavity (6) in the longitudinal direction (X);wherein) a first diameter (D1) of the cavity (6) is variable such that the first diameter (D1) in a first state is larger than a second diameter (D2) of the optical conductor (10) and the optical conductor (10) is displaceable in the cavity (6) relative to the insulating body (2), and the first diameter (D1) of the cavity (6) in a second state corresponds in at least a second and / or third direction (Y, Z) to the second diameter (D2) of the optical conductor (10) and the optical conductor (10) is fixed in the cavity (6). Flat ribbon cable according to claim 1, wherein the first diameter (D1) in the first state corresponds to at least 2 times, preferably 4 times, the second diameter (D2). Flat ribbon cable according to claim 1 or 2, wherein a first length (L1) of the optical conductor (10) along its central axis (M) corresponds to at least 1.1 times, preferably at least 1.5 times and most preferably at least 2 times a second length (L2) of the cavity (6) traversed. Flat ribbon cable according to claim 3, wherein the optical conductor (10) is arranged in a meandering shape at least in sections within the cavity (6). Flat ribbon cable according to one of claims 1 - 4, wherein the insulating body (2) has an elastic material at least in the region (2a) of the cavity (6), so that the optical conductor (10) is clamped by the cavity (6) in the second state of the cavity (6). Flat ribbon cable according to one of claims 1 - 5, wherein the optical conductor is pre-assembled and in the first state of the cavity (6) is completely displaceable in the cavity (6) relative to the insulating body (2). Manufacturing method for a flat ribbon cable (1), wherein the flat ribbon cable (1) comprises at least one ribbon-shaped insulating body (2), electrical conductors (4) in the insulating body (2), at least one separate cavity (6), and at least one optical conductor (10) arranged in the cavity (6), the method comprising at least the following steps: a) providing the insulating body (2) extending along a first longitudinal direction (X); b) pressurizing the cavity (6) with a liquid or gaseous medium so that the volume of the cavity (6) increases to a first state; c) inserting the optical conductor (10) into the cavity (6) at least until the optical conductor (10) extends over the entire length of the cavity (6);andd) ceasing the pressurization of the cavity (6) with the pressurized medium, so that the cavity (6) reduces its volume to a second state and fixes the optical conductor (10) in the cavity (6). Manufacturing method according to claim 7, wherein the optical conductor (10) which is placed in the cavity (6) comprises a pre-assembled optical conductor (10). Manufacturing method according to claim 7 or 8, wherein the insertion of the optical conductor (10) comprises inserting or pushing the optical conductor (10) into or through the cavity (6).

Images