CN114927267A - Anti-electromagnetic interference structure of sensor wire harness and vehicle cable system - Google Patents

Abstract

The invention discloses an anti-electromagnetic interference structure of a sensor wire harness and a vehicle cable system. Under the condition of not changing the hardware design of parts, a wiring harness processing mode for isolating coupling interference from system external wiring harnesses is provided for a system connected by only three wires, and the anti-interference effect of directly adopting a three-core shielding wire is realized by the design of lower cost.

Description

Anti-electromagnetic interference structure of sensor wiring harness and vehicle cable system

technical field

The invention relates to the technical field of shielded wires, in particular to an anti-electromagnetic interference structure of a sensor wire harness and a vehicle cable system.

Background technique

In the industry, the anti-electromagnetic interference treatment of the multi-conductor wire harness basically adopts the method of directly wrapping the shielding layer to realize the coupling and isolation effect of the system on the interference, and the increased cost of this method is often high. The lower cost twisted pair method is only suitable for the wire group of part of the electrical circuit in the wiring harness, and cannot improve the overall anti-interference ability of the wiring harness; for example, there are a large number of sensors in the vehicle, and the wiring harness group is composed of signals The sensor is composed of a power supply positive line and a negative line. The twisted pair of the sensor is only suitable for the power supply positive line and the negative line, or between the signal line and the negative line. No matter which group it is applied to, there will be a remaining wire without resistance. Therefore, the overall anti-interference effect is not ideal or completely ineffective.

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide an anti-electromagnetic interference structure for sensor wiring harness and a vehicle cable system, so that the interference can be eliminated before entering the sensor or controller, thereby improving the anti-electromagnetic interference performance of the system where the sensor is located.

In order to achieve the above purpose, the present invention proposes an anti-electromagnetic interference structure for a sensor wiring harness, including:

Stranded wire construction, including positive and negative power supply wires in a twisted arrangement; and,

a shielded wire, arranged side by side with the stranded wire structure, the shielded wire includes at least one signal wire and a shielding layer covering the outer surface of the signal wire, and both ends of the shielding layer are connected to the negative wire and grounded set up.

Optionally, the material of the shielding layer is a metal film or a metal woven mesh.

Optionally, a buffer layer is provided between the signal line and the shielding layer.

Optionally, the buffer layer is an insulating tape.

Optionally, a plurality of the shielding wires are provided, two ends of the shielding layers of the plurality of shielding wires are crimped, and the shielding layers of the plurality of shielding wires are all connected to the negative electrode wire and are grounded.

Optionally, the anti-electromagnetic interference structure of the sensor wire harness further includes an outer wrapping layer, and the outer wrapping layer wraps the stranded wire structure and the outer surface of the shielded wire.

Optionally, a buffer protection layer is provided between the outer wrapping layer, the twisted wire structure and the shielded wire.

The present invention also provides a vehicle cable system, including the above-mentioned anti-electromagnetic interference structure of the sensor wiring harness, the anti-electromagnetic interference structure at least includes:

Stranded wire construction, including positive and negative power supply wires in a twisted arrangement; and,

a shielded wire, arranged side by side with the stranded wire structure, the shielded wire includes at least one signal wire and a shielding layer covering the outer surface of the signal wire, and both ends of the shielding layer are connected to the negative wire and grounded set up.

In the technical solution of the present invention, a design for eliminating interference coupled to a three-wire sensor wire harness is provided. The wire harness design includes a shielded wire, a twisted pair structure of a positive power supply wire and a negative wire, and the shielded wire has a twisted pair structure. The shield is connected to the negative wire near the connector connecting both ends, and is grounded to the body ground. Through this design, the interference can be eliminated before entering the sensor or the controller, thereby improving the anti-electromagnetic interference performance of the system where the sensor is located. Therefore, without changing the hardware design of the components, the anti-interference effect of directly using the three-core shielded wire can be realized with a lower cost design, and the coupling interference from the external wiring harness of the system can be isolated. The cost of the core shielded wire.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

1 is a schematic diagram of an equivalent interference propagation path in the prior art;

2 is a schematic diagram of an embodiment of an anti-electromagnetic interference structure of a sensor harness provided by the present invention;

FIG. 3 is a schematic diagram of an equivalent interference propagation path in FIG. 2 .

Description of reference numbers:

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that, if there is a directional indication involved in the embodiment of the present invention, the directional indication is only used to explain the relative positional relationship, motion, etc. between the components under a certain posture. If the specific posture changes , the directional indication changes accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for the purpose of description, and should not be construed as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection required by the present invention.

In the prior art, taking an ordinary three-wire harness as an example, it consists of a signal line, a positive power line, and a negative line. Different interference voltage differences are formed between the positive wire of the power supply, the power supply and the ground of the vehicle body, and enter the electrical device through the wiring harness, causing different degrees of interference to the electrical device. Please refer to Fig. 1, U _x is the pressure difference formed by electromagnetic interference between any cables, U _y is the pressure difference formed by electromagnetic interference to the body ground, Z _LC is the direct coupling impedance between the wiring harness that propagates the interference and the interfered wiring harness, It usually includes capacitive reactance and inductive reactance. The solid line arrow _is the differential mode interference current, and the direction can be clockwise or counterclockwise. The dashed arrow is the common-mode interference current, U _y is coupled in by the interference-propagating wiring harness and the system wiring harness (any cable or all cables), and flows to the vehicle body ground through component grounding, etc.

The present invention provides an anti-electromagnetic interference structure of a sensor wiring harness and a vehicle cable system, which improves the anti-electromagnetic interference capability of the system without changing the design of electrical device hardware (including internal PCB and pins). Embodiments of the anti-electromagnetic interference structure of the sensor wiring harness provided by the present invention.

Referring to FIGS. 2 to 3 , the anti-electromagnetic interference structure 100 of the sensor wire harness includes a stranded wire structure and a shielded wire 2 . The stranded wire structures are arranged side by side, and the shielded wire 2 includes at least one signal wire 21 and a shielding layer 22 covering the outer surface of the signal wire 21. Both ends of the shielding layer 22 are connected to the negative wire 12 and Ground setting.

In the technical solution of the present invention, a design for eliminating interference coupled to a three-wire sensor wiring harness is provided. The shielding layer 22 of the shielded wire 2 is connected to the negative wire 12 near the connectors connecting both ends, and is grounded to the vehicle body ground. Through this design, the interference can be eliminated before entering the sensor or the controller, thereby improving the anti-electromagnetic interference performance of the system where the sensor is located. Therefore, without changing the hardware design of the components, the anti-interference effect of directly using the three-core shielded wire 2 is realized with a lower cost design, and the coupling interference from the external wire harness of the system can be isolated.

Specifically, please refer to FIG. 3, U _x is the pressure difference formed between the shielded wire 2 and the stranded wire structure by electromagnetic interference, U _y is the pressure difference formed by the electromagnetic interference on the body ground, and Z _LC is the wire harness and the ground of the transmission interference. The direct coupling impedance of the interference harness, usually including capacitive reactance and inductive reactance, the solid line arrow is the differential mode interference current, the direction can be clockwise or counterclockwise, through the wiring harness that propagates the interference and the shielded wire 2 or one of the stranded wires. Enter, and form U _x between the shielded wire 2 and the stranded wire structure, the dashed arrow is the common mode interference current, and U _y is coupled into the shielded wire 2 or the stranded wire structure by the wire bundle that propagates the interference. The positive wire 11 and the negative wire 12 of the power supply are twisted and matched with the shielded wire 2. The interference coupled to the structure in the cable on the vehicle is only the interference voltage Uy or There are two cases of the interference voltage difference Uz formed between the two. At the same time, because the shielding layer 22 of the shielded wire 2 is connected to the negative wire 12 and connected to the body ground, a sufficiently low impedance is formed between the two or between the two and the body ground. Therefore, most of the energy of the two pressure differences will be released between the shielding layer 22 and the negative wire 12 or between the two and the vehicle body respectively, forming a backflow, thereby avoiding the interference from the coupling when the wire harness is bundled together. Inside the electrical device of the system, the structure can improve the anti-electromagnetic interference ability without changing the design of the hardware of the electrical device.

In this embodiment, the shielding layer 22 is coated on the outside of a single signal line 21. The present invention does not limit the specific material of the shielding layer 22. In one embodiment, the material of the shielding layer 22 is a metal film. Or a metal braided mesh, that is, an insulating rubber sleeve is provided on the outside of the signal wire 21 and then a shielding layer of metal material is wrapped.

Furthermore, a buffer layer is provided between the signal line 21 and the shielding layer 22 , and the insulating buffer layer can provide buffer protection for the internal signal line 21 when it is damaged by external force. It should be noted that the present application does not limit the specific material of the buffer layer. In one embodiment, the buffer layer is an insulating tape.

In addition, for the case where the number of wires is larger, that is, there are multiple shielded wires 2, both ends of the shielding layers 22 of the multiple shielded wires 2 are crimped and arranged, and the multiple shielding layers 22 are connected to The negative electrode line 12 is also grounded, which can also satisfy the anti-interference effect. Further, on the basis of ensuring the three-wire system of the shielding wire 2, the positive power wire 11 and the negative wire 12, the specific implementation is: the total number of wires is n, and the remaining n-3=m The wire is replaced with a single-core shielded wire 2, and all the shielding layers 22 are crimped and connected to the ground wire connected to the negative wire 12 in the stranded wire structure. The final anti-interference effect is also equivalent to the multi-core shielded wire 2. , and the greater the number, the greater the advantage of the cost difference.

In order to improve the overall protection effect of the wire harness, the anti-electromagnetic interference structure 100 of the sensor wire harness further includes an outer wrapping layer, and the outer wrapping layer wraps the stranded wire structure and the outer surface of the shielded wire 2 . So as to protect the internal three-wire structure and prolong the service life.

Not only that, a buffer protection layer is provided between the outer wrapping layer, the stranded wire structure and the shielded wire 2 . It plays a buffering protection role for the internal wiring harness structure in the face of external force damage. It should be noted that the present application does not limit the specific material of the buffer protection layer, as long as it satisfies insulation, has a certain hardness, and can partially lower the external impact force.

The present invention further provides a vehicle cable system, including the above-mentioned anti-electromagnetic interference structure 100 for sensor wire harnesses, the vehicle cable system includes all the technical features of the above-mentioned anti-electromagnetic interference structure 100 for sensor wire harnesses, and therefore also has the above-mentioned anti-electromagnetic interference structure 100. The technical effects brought by all the technical features will not be repeated here.

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformations made by the contents of the description and drawings of the present invention, or the direct/indirect application Other related technical fields are included in the scope of patent protection of the present invention.

Claims (6)

1. An anti-electromagnetic interference structure of a sensor harness, comprising:

the stranded wire structure comprises a power supply positive wire and a power supply negative wire which are stranded; and (c) a second step of,

the shielding wire, with the stranded conductor structure sets up side by side, the shielding wire includes an at least signal line and cladding the shielding layer of signal line surface outward, the both ends of shielding layer all are connected to negative pole line and ground connection setting.

2. The anti-electromagnetic interference structure of a sensor harness according to claim 1, wherein the shielding layer is made of a metal film or a metal woven mesh.

3. The anti-electromagnetic interference structure of a sensor harness according to claim 1, wherein a buffer layer is provided between the signal line and the shielding layer.

4. The anti-electromagnetic interference structure of a sensor harness according to claim 3, wherein the buffer layer is an insulating tape.

5. The anti-electromagnetic interference structure of a sensor harness according to claim 1, wherein the plurality of shield wires are provided, the shield layers of the plurality of shield wires are crimped at both ends thereof, and the shield layers of the plurality of shield wires are connected to the negative electrode wire and grounded.

6. A vehicle cable system characterized by comprising the anti-electromagnetic interference structure of the sensor harness according to any one of claims 1 to 5.

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