CN1194451C - Cable plug processing method - Google Patents

Abstract

The invention relates to a cable plug processing method, which is mainly used for crimping processing between a multi-core coaxial cable with a total braid and a high-density D-type connector, in which the grounding conductor is kept without cutting it and then soldering the electronic Wire, strip off the insulation layer of the inner conductor of a single coaxial cable, and put the wire sheath and heat shrinkable sleeve on the inner conductor and the grounding conductor in turn, which can solve the reliability of the contact between the inner conductor and the connector knife edge; in the injection molding of the plug After the mold is coated with copper foil and tinned, and the outer mold is injected without using metal shell components, the shielding function of the plug can also be realized, and the cost can be greatly reduced; in addition, by changing the injection mold, it can also adapt to different outer diameters cable.

Description

Cable plug processing method

technical field

The present invention relates to the field of communication products, and more specifically relates to a cable plug processing method, which can be applied to wireless products, transmission products, switching products, data communication products, access network products, etc. It is of great significance to improve the reliability of the electrical connection between them and reduce the processing cost of cable plugs.

Background technique

There are two main processing methods for combining high-density D-type connectors with overall braided communication cables, namely welding and crimping. Because the material of the welded cable will become relatively brittle and hard at the solder point, it is easy to break during use and cause failure. Therefore, the application of the piercing and crimping processing method is increasing.

The piercing knife edge of the connector adopting the piercing processing method has certain requirements on the conductor diameter of the cable wire, the material and thickness of the wire sheath. For example, the knife edge of AMP's high-density D-type connector is only suitable for piercing crimping of flat wires or twisted-pair wires with a wire specification of 28-30AWG.

In order to ensure the shielding performance of the cable, after the connector and the cable wire are processed, the metal shell and the connector are generally used to assemble a complete cable plug. The outlet part of the metal shell should have good contact with the overall braiding layer of the cable.

1. The structure of the press-fit high-density D-type connector

Commonly used connectors are crimp-type high-density D-type connectors, such as AMP's crimp-type high-density connectors, which are mainly composed of shielded plugs and termination covers, as well as shells. And accessories, the structure of the shielding plug and the wiring piece are shown in Figure 1 and Figure 2 respectively. The tail of the plug is provided with a knife edge, which is used to pierce the wire sheath of the wire and form an electrical path with the conductor inside the wire; the wire mounting piece is used for arranging, installing, and clamping the wire, which is convenient for puncture processing. This kind of connector is usually only suitable for puncture processing of 28-30AWG flat or twisted pair wires, and the number of pins is usually 40, 50, 68, 80, 100, etc.

2. Structure with total braided multi-core coaxial cable

The coaxial cable with overall braiding is usually 8 cores, and sometimes 4 cores, 16 cores, 32 cores, etc. are used. The commonly used models of 8-core coaxial cables are SFYVP75-2-1 or SYVP75-2-1, etc. The cross-sectional schematic diagram of the coaxial cable with the model SFYVP75-2-1 is shown in Figure 3. Including outer sheath layer 1, overall braiding layer 2, polyester film 9, tear wire 10 and inner 8 single coaxial cables, each single coaxial cable includes sheath layer 4, braiding layer 5, grounding Conductor 3, insulating layer 8, fluoroplastic 7 and inner conductor 6.

3. The current processing method of a multi-core coaxial cable with a total braid and a crimped high-density D-type connector includes the following steps:

3-1. Offline and stripping of multi-core coaxial cable with overall braiding

As shown in Figure 4, use a cable disconnecting machine or other special tools to cut off the cable according to the length of the cable; use a stripping machine or a special wire stripper to strip the outer sheath layer 1 of the cable, and the length is generally 40±2mm. The specific length should be determined according to the size of the connector shell; use diagonal pliers to strip the total braiding layer 4 of the cable to a distance of 5mm from the outer sheath of the cable. Cut the polyester film 9 and the tear line 10 with diagonal pliers or scissors.

3-2. Stripping of a single coaxial cable

As shown in Figure 5, first strip the sheath layer 4 of a single coaxial cable with a stripping machine or a special wire stripper, and the length is 35 ± 2.0mm, and use a diagonal pliers to remove the braided layer 5 of a single coaxial cable from the The stripped root position of the sheath layer 4 is cut off, but the grounding conductor 3 in the braided layer 5 cannot be completely cut off, and 3-5mm needs to be reserved; Place the heat-shrinkable sleeve 12 on the point. The length of the wire 11 after welding should be consistent with the length of the inner conductor 6 .

For cables without grounding conductors, a certain amount and length of braided copper wires can be reserved, twisted into a rope, and then welded with electronic wires and covered with heat shrinkable sleeves.

3-3. Wire installation and crimping

According to the wiring relationship required by the cable drawing design, arrange the inner conductor 6 of each single coaxial cable with insulating layer 8 and the electronic wire 11 welded on the grounding conductor, and put them into the wire mounting sheet shown in Figure 2 in turn , neatly trimmed.

Insert the wire lug that has already been placed into the base of the connector and crimp it. Wherein the inner conductor 6 and the electronic wire 11 are arranged in two ways in the wiring sheet: as shown in Figure 6, it is the oblique way of the cable plug, and as shown in Figure 7, it is the straight way of the cable plug.

3-4. Internal mold injection molding

Arrange the crimped connectors according to the requirements of the design drawings, and place them in the mold of the injection molding machine to inject the inner mold. The shapes of the oblique and straight outlet connectors after completion are shown in Figure 8 and Figure 9 respectively.

3-5. Assemble the shell

Install the connector of the injected inner mold in the metal shell, and tighten the mounting screws to complete the whole process.

The cable obtained by the above processing method has the following disadvantages:

One is that the electrical reliability of the cable is poor. As mentioned earlier, this connector is more suitable for processing flat wires and twisted pairs. For coaxial cable, when adopting prior art processing, because what the knife edge of connector punctured is the insulating layer 8 outside the inner conductor 6 of a single coaxial cable, and the outer diameter and hardness of this insulating layer are far more than with 28-30AWG The large twisted-pair wire sheath easily deforms the edge of the knife, resulting in unreliable contact between the inner conductor of a single coaxial cable and the edge of the connector. Figure 10 and Figure 11 show the inner conductors of the twisted-pair wire and the coaxial cable respectively. It can be seen from the schematic diagram of crimping on the edge of the connector that the former does not deform, while the latter deforms more seriously due to the thicker insulating layer 6 outside the inner conductor 6 . According to the current usage statistics, about 30% of the cables processed by the existing technology have signal failure during use; There is a potential failure of poor contact. In addition, there is a solder joint between the grounding conductor 3 and the electronic wire 11 of the cable, and the wire at the solder joint is relatively brittle and hard. During the use of the cable, when the cable is bent many times, it is easy to cause breakage at this point.

The second is that the processing cost is relatively high. To ensure the shielding performance of the cable plug, a metal shell needs to be used, and the price of the metal shell is relatively expensive. For example, the current price of a set of 68PIN high-density connector shells is between RMB 20-30. In addition, the size of the outlet part of the shell is relatively fixed, and when the outer diameter of the braided cable does not match the shell, it cannot be processed normally.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new processing method to carry out the crimping process between the multi-core coaxial cable with a total braid and the high-density D-type connector, which can make the connection between the connector and the wire It is very reliable, the processing cost is greatly reduced, and at the same time, it can adapt to the situation of wires with different outer diameters.

The technical solution of the cable plug processing method of the present invention will be described below by comparing with the existing processing methods.

(1) When stripping the sheath and braid of each single coaxial cable, the grounding conductor in the braid should be kept and the grounding conductor should not be damaged;

(2) It is necessary to peel off the insulation layer of each single coaxial cable to expose the inner conductor. In order to avoid short circuit between the inner conductor and the grounding conductor, the insulation layer is about 5mm away from the stripped root of the sheath layer. cut off

(3) Put the first wire sheath on the inner conductor of each single coaxial cable, then put the first heat-shrinkable sleeve on the junction of the first wire sheath and the insulating layer, and heat-shrink and fix it , which makes the knife edge of the connector pierce the wire sheath during the crimping step, rather than the insulation layer outside the inner conductor, so it will not cause deformation of the knife edge;

(4) Put the second sheath on the grounding conductor of each single coaxial cable, and then put the second heat shrinkable sleeve on the stripped root of the sheath layer to cover the inner conductor and the grounding conductor, and put all the The heat shrinkage of the second sleeve is fixed, because the grounding conductor is not cut and welded, which can eliminate the disadvantages that the wire at the welding point is relatively brittle and hard in the existing method, and is easy to break;

(5) After the inner mold is injected, cover the connector with copper foil, so that the metal shell of the connector and the total braiding layer of the cable are in full contact with the copper foil at 360 degrees, and then the copper foil and the connector The junction is soldered around the joint, and the joint between the copper foil and the total braid is soldered around the circle, and then the copper foil-wrapped connector is placed on the injection molding machine to inject the outer mold, and the finished cable is obtained. Copper foil is used here Instead of a metal shell for shielding, the cost can be greatly reduced.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Description of drawings

Figure 1 is a structural schematic diagram of a crimped high-density D-type connector;

Fig. 2 is a front view of the connector wiring piece;

Figure 3 is a schematic cross-sectional view of the SFYVP75-2-1*8 cable;

Fig. 4 is a schematic diagram of stripping the outer sheath and stripping the coaxial cable in Fig. 3;

Fig. 5 is a schematic diagram of stripping a single coaxial cable;

Figure 6 and Figure 7 are schematic diagrams of cable plugs with oblique outlets and straight outlets crimped respectively;

Fig. 8 and Fig. 9 are respectively the schematic diagrams of the cable plugs with oblique outlets and straight outlets after internal mold injection molding;

Fig. 10 is a schematic diagram of piercing the sheath of a 28-30AWG double-hinged wire with a connector knife edge;

Fig. 11 is a schematic diagram of piercing the insulating layer outside the inner conductor of a single coaxial cable with a connector knife edge;

Fig. 12 is the flowchart of processing method of the present invention;

Fig. 13 is a schematic diagram of the inner conductor and the ground conductor with the sheath and the heat-shrinkable sleeve;

Fig. 14 is a schematic diagram of coating copper foil on the plug body of the injection molded inner mold;

Figure 15 and Figure 16 are the front view and left view of the cable plug with oblique outlet;

Figure 17 and Figure 18 are the front view and left view of the straight cable plug.

Detailed ways

The process flow of the processing method of the present invention is shown in Fig. 12, and the SYVP75-2-1*8 coaxial cable is taken as an example to describe in detail below.

Step 101. Strip the cable with the overall braid, that is, take a section of cable, first strip off its outer sheath layer, and then peel off the overall braid layer in the outer sheath layer to expose each single coaxial cable inside , this step is the same as 3-1 in the background technology section, and will not be repeated here.

Step 102, peel off the sheath layer and braid layer of each single coaxial cable inside, wherein first strip the sheath layer 4 of the single coaxial cable with a stripping machine or a special wire stripper, and the stripping length is 35±2.0mm , and then use diagonal pliers to cut off the braided layer 5 from the stripped root of the sheath layer 4. During this process, the grounding conductor 3 in the braided layer 5 should be retained, and the grounding conductor should not be damaged.

Step 103: Use a special wire stripper to strip off a certain length of insulation layer 8 on the inner conductor 6 of each single coaxial cable. If there is a fluoroplastic 7, you need to strip the fluoroplastic 7 together to expose the inner conductor 6, and The inner conductor must not be damaged, and the length of the insulating layer 8 needs to be about 5 mm from the stripped root of the sheath layer 5, so as not to touch the ground conductor 3 in the braided layer and cause a short circuit.

Step 104, as shown in Figure 13, put a sheath and a heat-shrinkable sleeve on the inner conductor that has been stripped of the insulation layer. Since the specification of the inner conductor 6 of the cable SYVP75-2-1*8 is 30AWG, it can be put on it The specification is the wire sheath 16 of the 28AWG wire, the length of the wire sheath is about 30mm, and then the heat-shrinkable sleeve 14 is put on the junction of the wire sheath and the insulating layer 8 of the inner conductor, and then heat-shrinked and fixed with a heat gun.

Step 105, put a wire sheath 17 with a length of about 35mm and a specification of 28AWG wire on the ground conductor 3 of the braided layer, and then put a heat shrinkable sleeve 15 near the stripped root of the sheath layer 4, and put the inner conductor and The grounding conductors are all covered, and then heat-shrinked and fixed with a heat gun, so that the inner conductor 6, the grounding conductor 3 and the sheath layer 4 are integrated.

In order to facilitate identification in the following steps, the wire sheath 16 on the inner conductor 6 and the wire sheath 17 on the grounding conductor 3 can be distinguished by different colors, for example, the former uses a red wire sheath, and the latter uses a black wire Skin.

Step 106, wire installation and crimping, this step is the same as 3-3 in the background technology part, and will not be repeated here. However, in this step, the knife edge of the connector pierces the sheath of the 28AWG wire instead of the insulating layer 8 outside the inner conductor 6, so it will not cause deformation of the knife edge, and can ensure that the inner conductor of a single coaxial cable is connected to the Reliable contact with the tool edge.

Step 107: Injection molding of the inner mold, this step is the same as 3-4 in the background technology section, and will not be repeated here.

Step 108, as shown in Figure 14, cover the connector of the injection molded inner mold with the copper foil 18 with adhesive on the inner layer, and it is required that the metal shell of the connector and the overall braiding layer 2 of the cable should be 360 degrees to the copper foil Full contact; then use an electric soldering iron to solder around the junction of the copper foil and the connector, and at the same time solder around the junction of the copper foil and the overall braid 2, the position of soldering 19 is black and thick in Figure 14 shown in the line part.

Step 109: Put the copper-foil-wrapped connector on the injection molding machine and inject the outer mold. After completion, the finished oblique outlet plug is shown in Figures 15 and 16, and the finished straight outlet plug is shown in Figures 17 and 18.

Step 110, inspect the finished cable connector.

As can be seen from the above steps, one of the main points of the processing method of the present invention is to strip off the outer insulating layer of the inner conductor of each single coaxial cable in the multi-core cable, keep the grounding conductor instead of cutting off and then weld the tape The electronic wire with insulation layer, and the inner conductor and grounding conductor are covered with wire sheath and heat-shrinkable sleeve, which is the key to ensure the reliability and stability of the cable. In the original processing method, due to hidden dangers in the contact between the knife edge and the conductor, signal interruption may occur at any time during the use of the equipment. However, the cable processed by the present invention has no hidden trouble because the contact between the conductor and the edge of the connector is very reliable. According to the statistical data obtained in actual use, the circuit breaking failure rate caused by the poor contact between the knife edge and the conductor when the cable processed by the method of the present invention is used on the equipment is reduced from 30% to nearly 0.

The second key point of the processing method of the present invention is that after the inner mold of the plug is injected, the copper foil is coated and tinned, and the shielding function of the plug is also realized without using a metal shell component. Because no metal shell is needed, the cost of the cable plug processed by the method of the present invention is 40-50% lower than that of the prior art, because the cost of the plastic shell is far lower than that of the metal shell of the purchased part, and the shielding performance can be achieved by cladding copper. foil to guarantee. In addition, the method of changing the injection mold can be used to adapt to wires with different outer diameters, which makes up for the limitations of the prior art.

Claims (7)

1, a kind of cable plug making process is characterized in that, may further comprise the steps:

(1), get one section cable, peel off its external sheath layer earlier, peel off the total braid in the external sheath layer again, expose each inner bar single coaxial cable;

(2), peel off the restrictive coating of each bar single coaxial cable, peel off braid again;

(3), peel off the insulating barrier of each bar single coaxial cable, expose inner wire;

(4), on the inner wire of each bar single coaxial cable the suit first line skin, fix then at intersection suit first heat-shrinkable T bush of described first line skin and insulating barrier, and with its pyrocondensation;

(5), on the earthing conductor of each bar single coaxial cable the suit second line skin, root position suit second heat-shrinkable T bush of peeling off at the single coaxial cable restrictive coating all entangles inner wire and earthing conductor then, and the described second heat-shrinkable T bush pyrocondensation is fixed;

(6), arrange the inner wire and the earthing conductor of each bar single coaxial cable, and put into the wiring sheet of connector successively, more described wiring sheet is inserted in the pedestal of connector and carries out crimping by wiring relation;

(7), the connector that pressure is carefully connected the wire is put into injection moulding internal mold in the injection molding machine mould;

(8), coat, rounded in the junction of Copper Foil and connector then and carry out scolding tin, and Copper Foil rounded with the junction of total braid carry out scolding tin with the connector of Copper Foil with the injection formed internal mold;

(9), the connector that will wrap Copper Foil is placed on injection moulding external mold on the injection molding machine, obtains finished cable.

2, method according to claim 1 is characterized in that, also comprises the step that root position is cut off polyester film and tear line of peeling off from external sheath layer in described (1) step.

3, method according to claim 1, it is characterized in that, described cable is the total braiding of band multicore coaxial cable, and the length of the cable jacket layer of peelling off in described (1) step is between 38-42mm, and total braid is then peeled off the about 5mm of root from the distance external sheath layer and peelled off and cut off.

4, method according to claim 3 is characterized in that, the length of the single coaxial cable restrictive coating of peelling off in described (2) step is 33-37mm, and described single coaxial cable braid is to cut off from the root position of peeling off of restrictive coating.

5, method according to claim 4 is characterized in that, also comprises the step that the fluoroplastics in the insulating barrier are divested together in described (3) step; Insulating barrier is to cut off from the about 5mm of the root position of peeling off of distance restrictive coating.

According to each described method among the claim 1-5, it is characterized in that 6, in described (8) step, requiring the metal shell of connector is that 360 degree contact entirely with Copper Foil, total braid of cable also is that 360 degree contact entirely with Copper Foil.

7, according to each described method among the claim 1-5, it is characterized in that the internal layer of described Copper Foil has viscose glue.

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