A method for preparing a silicone insulated new energy vehicle shielded cable

Abstract

The present invention discloses a method for preparing a silicone insulated new energy vehicle shielded cable, which belongs to the technical field of wire and cable manufacturing. The silicone insulated new energy vehicle shielded cable comprises a twisted conductor, a silicone insulating layer, a braided shielding layer, and a sheath layer arranged from the inside to the outside, and is characterized in that a graphite carbon black layer is arranged between the silicone insulating layer and the braided shielding layer. The present invention adopts a graphite carbon black adhesive layer to replace the wrapped aluminum-plastic composite tape layer, which increases the flexibility and makes all cable components fully match their working temperature. The graphite carbon black adhesive layer has a semi-conductive property, and the semi-conductive layer is in good contact with the shielded braided or wound copper wire, and there is no problem of aluminum foil surface oxidation.

Description

Technical Field

[0001] The invention belongs to the technical field of wire and cable manufacturing, and in particular relates to a method for preparing a silicone insulated new energy vehicle shielded cable. Background Art

[0002] In recent years, my country's new energy vehicle technology has developed rapidly. With the maturity of new energy vehicle technology, new energy vehicles are becoming more and more popular. The wire and cable industry is the second largest industry in China after the automobile industry.

[0003] New energy vehicle shielded cable is a type of cable. At present, the charging and discharging cables of new energy vehicles mainly use shielded cables with silicone rubber insulation. There are two main shielding structures of shielded cables: one is a braided or wound copper wire (or tinned copper wire) shielding structure. This shielding structure cable is suitable for vehicles with low requirements for signal shielding; the other is a braided or wound copper wire (or tinned copper wire) plus aluminum-plastic composite film wrapped shielding structure. This shielding structure cable is mainly used for vehicle systems with strict shielding requirements such as new variable frequency motors.

[0004] The first type of shielded cable with braided or wound copper wire as the shielding structure has the following advantages and disadvantages: 1. Good flexibility; 2. Beautiful cable appearance; 3. Small bending radius; 4. The shielding effect is greatly affected by the braiding density, especially when the braiding gaps are uneven, which seriously reduces the shielding effect of the cable; 5. Due to the gaps between the copper wires, the cable has poor shielding against high-frequency signals.

[0005] The second type of shielded cable with braided or wound copper wire + wrapped aluminum-plastic composite tape as the shielding structure has the following advantages and disadvantages: 1. The shielding effect is good. The aluminum-plastic composite tape covers the surface of the cable and transmits the induced signal in time through the copper wire. 2. Due to the wrapping of the aluminum-plastic composite tape, the cable is harder and has a larger bending radius; 3. The aluminum layer of the aluminum-plastic composite tape is easily oxidized, resulting in poor contact with the braided wire. As time goes by, the shielding effect will become worse and worse than the newly produced ones; 4. The working temperature of the aluminum-plastic composite tape is generally around 125 degrees, which does not match the 180~200 degrees of silicone rubber. If it is used for a period of time, the plastic tape will break due to aging, which will affect the shielding effect.

[0006] Low noise cable is another type of cable.

[0007] The manufacture of low-noise cables mainly uses insulating coated graphite carbon black materials to achieve insulation effects. However, untreated graphite carbon black has poor adhesion to insulation and will fall off after a period of use, affecting the shielding and noise reduction effects and affecting the long-term use of the cable.

[0008] In summary, it is necessary to design a shielded cable for new energy vehicles that integrates the advantages of various shielded cables. Summary of the invention

[0009] In view of the problems existing in the prior art, the present invention provides a method for preparing a silicone insulated new energy vehicle shielded cable which solves the problem that the shielded cables currently used in new energy vehicles all have their own obvious defects and shortcomings.

[0010] The present invention is achieved in this way. A method for preparing a silicone insulated new energy vehicle shielded cable comprises a twisted conductor, a silicone insulation layer, a braided shielding layer, and a sheath layer arranged from the inside to the outside, characterized in that a graphite carbon black layer is arranged between the silicone insulation layer and the braided shielding layer, the braided shielding layer is a tinned copper wire braided layer, and the graphite carbon black layer is bonded to the outer surface of the silicone insulation layer through a liquid silicone curing film to form a graphite carbon black glue layer; the cable preparation method comprises the following steps:

[0011] Step 1: preparing a stranded conductor;

[0012] Step 2: manufacturing a bonding layer of the silicone insulation layer and the graphite carbon black glue layer on the outside of the stranded conductor, including the following steps:

[0013] 1) Covering the outer layer of the twisted conductor with a silicone rubber insulating material, and curing the outer layer of the silicone rubber insulating material to form the silicone insulating layer arranged on the outer side of the twisted conductor;

[0014] 2) Plasma surface treatment is performed on the outer surface of the silicone insulation layer;

[0015] 3) Apply liquid silicone on the outer surface of the silicone insulation layer to form a silicone film;

[0016] 4) Applying the graphite carbon black mixed powder to the outer layer of the silicone film;

[0017] 5) Curing the organic silicon film;

[0018] Step 3: Weaving or winding tinned copper wire on the outside of the graphite carbon black glue layer to form the braided shielding layer;

[0019] Step 4: coating the outer side of the braided shielding layer with vulcanized silicone rubber to form the sheath layer;

[0020] The graphite carbon black mixed powder comprises the following raw materials by mass fraction:

[0021] 30-35 parts of semi-conductive carbon black;

[0022] Graphite 65~70 parts;

[0023] 1.5~2.5 parts of coupling agent;

[0024] Adhesive additive 0.5~1.5 parts;

[0025] 0.01~0.5 parts of carbon nanotubes.

[0026] The preparation method of the graphite carbon black mixed powder comprises:

[0027] S1. Put the semiconductor carbon black and graphite into a high-speed kneader, stir the semi-conductive carbon black and carbon black for 1-2 minutes;

[0028] S2. Add adhesive additive to make graphite and carbon black condense into particles, and control the stirring time to 4-5 minutes;

[0029] S3, spraying carbon nanotubes and stirring for 2-3 minutes;

[0030] S4. Add a coupling agent and control the stirring time to 8-10 minutes to obtain a graphite carbon black mixed powder, wherein a coupling agent film is formed on the particle surface of the graphite carbon black mixed powder.

[0031] Adding a small amount of semiconductor material formed by carbon nanotubes to the graphite carbon black mixed powder can improve the conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the structure of the cable in the present invention;

[0033] Figure 2 It is a structural schematic diagram of the cable cabling process in the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] In order to solve the problem that the shielded cables currently used in new energy vehicles all have their own obvious defects and shortcomings, the present invention provides a method for preparing a silicone insulated new energy vehicle shielded cable. The silicone insulated new energy vehicle shielded cable has good shielding effect, good flexibility, small bending radius and good anti-oxidation performance. In order to further illustrate the structure of the present invention, the detailed description is as follows in conjunction with the accompanying drawings:

[0036] Embodiment 1

[0037] See also Figure 1 A method for preparing a silicone insulated new energy vehicle shielded cable, the cable includes a twisted conductor 1, a silicone insulation layer 2, a graphite carbon black layer 5, a braided shielding layer 3 and a sheath layer 4 arranged from the inside to the outside.

[0038] The braided shielding layer is a copper wire braided layer or a copper wire winding layer. The graphite carbon black layer is bonded to the outer surface of the silicone insulation layer through a liquid silicone curing film to form a graphite carbon black adhesive layer. The graphite carbon black layer and the liquid silicone are vulcanized and bonded together to form a continuous and complete graphite carbon black adhesive layer, which has both the conductive shielding effect of graphite carbon black and the flexibility and continuity of the silicone film. At the same time, when the cable is subsequently processed into terminals, it is only necessary to peel off the cured liquid silicone film together with the attached graphite carbon black, without affecting the insulation crimping terminal process. This shielded cable has the advantages of existing cables with different shielding structures, such as good shielding effect, good flexibility, small bending radius and good anti-oxidation performance.

[0039] Embodiment 2

[0040] A method for silicone insulating shielded cables for new energy vehicles:

[0041] First, prepare graphite carbon black mixed powder as a backup material. The graphite carbon black mixed powder includes the following raw materials by mass fraction:

[0042] 30-35 parts of semi-conductive carbon black;

[0043] Graphite 65~70 parts;

[0044] 1.5~2.5 parts of coupling agent;

[0045] Adhesive additive 0.5~1.5 parts;

[0046] 0.01~0.5 parts of carbon nanotubes.

[0047] The preparation method comprises the following steps:

[0048] S1. Put the semiconductor carbon black and graphite into a high-speed kneader, stir the semi-conductive carbon black and carbon black for 1-2 minutes.

[0049] S2. Add adhesive additives to agglomerate graphite and carbon black into larger particles. The stirring time is controlled to 4-5 minutes.

[0050] S3, spray carbon nanotubes, stir for 2-3 minutes. Add a small amount of semiconductor material formed by carbon nanotubes to the graphite carbon black mixed powder to improve the conductivity.

[0051] S4. Add coupling agent and control the stirring time to 8-10 minutes to obtain graphite carbon black mixed powder, and form a coupling agent film on the particle surface of the graphite carbon black mixed powder. Put it into a moisture-proof and sealed container for standby use.

[0052] Cable cabling consists of the following steps, see Figure 2 :

[0053] Step 1: Prepare the stranded conductor. The stranded conductor is made by a stranding machine.

[0054] Step 2: Making a bonding layer of a silicone insulation layer and a graphite carbon black glue layer on the outside of the stranded conductor, including the following processes:

[0055] 1) The outer layer of the twisted conductor is coated with silicone rubber insulation material, and the outer layer of the silicone rubber insulation material is cured to form a silicone insulation layer arranged on the outer side of the twisted conductor. That is, after the twisted conductor is pulled out from the winding machine, it passes through the silicone rubber extruder head 6, and the outer surface of the twisted conductor is coated with a layer of silicone rubber insulation material. The twisted conductor coated with silicone rubber insulation material passes through the infrared heating box 7, and the outer layer is quickly vulcanized, so that the silicone rubber insulation material forms a silicone insulation layer with a certain strength.

[0056] 2) Plasma surface treatment is performed on the outer surface of the silicone insulation layer. Two to three plasma surface treatment devices are arranged 150 mm in front of the silicone rubber extruder head to continuously treat the silicone insulation layer to increase its surface adhesion and reduce the gap between the silicone insulation layer and the subsequently cured silicone film. In this embodiment, the plasma surface treatment device is a plasma blowing head 8 arranged above and below the wire body.

[0057] 3) Apply liquid silicone on the outer surface of the silicone insulating layer to form an organic silicone film. Specifically, the wire body treated in the previous step is immersed in the box body 9 containing liquid silicone, and the liquid silicone is coated on the outside of the silicone insulating layer. The liquid silicone is rapidly solidified due to contact with the high-temperature insulation of the silicone insulating layer by infrared radiation in the previous step, forming a continuous inner layer of the organic silicone film, and the outer layer of the organic silicone film is still in liquid state.

[0058] 4) Applying the graphite carbon black mixed powder to the outer layer of the organic silicon film. The wire body processed in the previous step enters the powder box 10, and the graphite carbon black is coated on the outer layer of the organic silicon film, and the graphite carbon black adheres to the outer layer of the organic silicon film.

[0059] 5) Curing the organic silicon film. After the previous step, the wire body enters the hot air oven 11 to continue to cure the organic silicon film and at the same time deeply vulcanize the silicone rubber insulation. In this step, a graphite carbon black glue layer combined with the silicone insulation layer is formed.

[0060] Step 3: Weave or wrap copper wire on the outside of the graphite carbon black glue layer to form a braided shielding layer. Weave or wrap the copper wire (tinned copper wire), and the pressure applied by the copper wire weaving further increases the adhesion between the graphite carbon black layer and the liquid silicone film.

[0061] Step 4: Coat the outer side of the braided shielding layer with vulcanized silicone rubber to form a sheath layer. Use a vacuum extruder to make the sheath layer so that the sheath material can better adhere to the graphite black exposed in the braiding gap. At the same time, in terms of process control, increase the sheath vulcanization time by 5~10% to increase the adhesion between the sheath and graphite black.

[0062] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a silicone insulated new energy vehicle shielded cable, the cable comprising a twisted conductor, a silicone insulation layer, a braided shielding layer, and a sheath layer arranged from inside to outside, characterized in that: A graphite carbon black layer is arranged between the silicone insulation layer and the braided shielding layer, the braided shielding layer is a tinned copper wire braided layer, and the graphite carbon black layer is bonded to the outer surface of the silicone insulation layer through a liquid organic silicone curing film to form a graphite carbon black glue layer; the preparation method of the cable comprises the following steps: Step 1: preparing a stranded conductor; Step 2: manufacturing a bonding layer of the silicone insulation layer and the graphite carbon black glue layer on the outside of the stranded conductor, including the following steps: 1) Covering the outer layer of the twisted conductor with a silicone rubber insulating material, and curing the outer layer of the silicone rubber insulating material to form the silicone insulating layer arranged on the outer side of the twisted conductor; 2) Plasma surface treatment is performed on the outer surface of the silicone insulation layer; 3) Apply liquid silicone on the outer surface of the silicone insulation layer to form a silicone film; 4) Applying the graphite carbon black mixed powder to the outer layer of the silicone film; 5) Curing the organic silicon film; Step 3: Weaving or winding tinned copper wire on the outside of the graphite carbon black glue layer to form the braided shielding layer; Step 4: coating the outer side of the braided shielding layer with vulcanized silicone rubber to form the sheath layer; The graphite carbon black mixed powder comprises the following raw materials by mass fraction: 30-35 parts of semi-conductive carbon black; Graphite 65~70 parts; 1.5~2.5 parts of coupling agent; Adhesive additive 0.5~1.5 parts; 0.01~0.5 parts of carbon nanotubes.

2. The method for preparing the silicone insulated new energy vehicle shielded cable according to claim 1, characterized in that: The preparation method of the graphite carbon black mixed powder comprises: S1. Put the semiconductor carbon black and graphite into a high-speed kneader, stir the semi-conductive carbon black and carbon black for 1-2 minutes; S2. Add adhesive additive to make graphite and carbon black condense into particles, and control the stirring time to 4-5 minutes; S3, spraying carbon nanotubes and stirring for 2-3 minutes; S4. Add a coupling agent and control the stirring time to 8-10 minutes to obtain a graphite carbon black mixed powder, wherein a coupling agent film is formed on the particle surface of the graphite carbon black mixed powder.

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