JP5373864B2 - Connection structure between multi-core cable and multi-core connector - Google Patents

Abstract

The purpose of the present invention is to prevent a resin coating (9) from entering a hole for a terminal strip (6) of a multicore connector. In a connection structure between a multicore cable and a multicore connector a terminal strip (4) is inserted into a multicore connector (5). The multicore connector (5) has a gap in a hole (6) into which the terminal strip (4) is inserted or has a hole (6) into which the terminal strip (4) is not inserted. The ratio (S2 / S1) of the wall area (S2) of the hole (6) to the whole area (S1) of the hole (6) is set to 0.5 to 20 and the melt viscosity of the resin coating (9) is set to 0.5 to 200 Pa·s. Thereby, the melt viscosity of the mold material and the surface tension based on the difference between the hole area and the surrounding area prevent the melted resin (9) from leaking out from the hole for a terminal strip (6) and the gap, and thus a resin coating (9) having good transferability is formed with an external form that is identical to the mold cavity without significant sink marks occurring on the surface of the resin coating (9). Thus, a resin coating (8) formed on the resin coating (9) as well has good transferability.

Description

  The present invention relates to a connection structure between a movable multi-core cable for a robot or the like and a multi-core connector, and a connection method thereof.

For example, a cable for sending power and signals to a device such as a robot needs to have flexibility in order to follow the movement of the robot, and a multi-core cable (hereinafter referred to as appropriate) to send and receive many signals. Are referred to as “cables”). When this cable is described with reference to FIGS. 1 and 2 showing the embodiment of the present application (hereinafter the same), as shown in the figure, a large number (multi-core) of insulated core wires 3 are covered with a sheath 2. (Patent Document 1).
For connection between the cable 1 and a device such as a robot, a multi-core connector (hereinafter referred to as “connector” as appropriate) is used (Patent Document 2), and the multi-core connector 5 is shown in FIG. 2, a plurality of holes 6 into which the terminal pieces 4 fixed to the ends of the insulating core wire 3 enter are provided.

As shown in FIGS. 1 and 2, the connection between the multi-core cable 1 and the multi-core connector 5 is provided with terminal pieces 4 at each end of each insulated core wire 3 of the cable 1, It is carried out by being inserted into each hole 6 of the connector 5.
At this time, as can be understood from FIGS. 1 and 2, the sheath 2 is peeled off at the terminal portion of the cable 1 so that the insulation core wire 3 is exposed (exposed) by a required length, and in this state, the connector 5 Connected to.

On the other hand, the connecting portion between the device and the cable has conventionally been such that the end of the cable 1 (cable sheath 2) is fixed to the device with a metal fitting or the like so that no bending force is applied to the exposed insulating core wire 3 portion. However, when fixed, there is a case where a drag force is generated on the movement of the device, and a bending force is applied to the exposed insulating core wire 3 part, and the insulation core wire 3 is disconnected due to the bending. .
For this reason, the cable 1 is not fixed to the device with metal fittings, and the connection portion between the cable 1 and the device is made flexible (highly flexible), and ingenuity to prevent disconnection of the insulating core wire 3 is necessary. In general, as shown in FIG. 4, a connection structure between the cable 1 and the connector 5 in which the resin sheath 8 is formed by enclosing the terminal of the cable sheath 2 and the connector 5 including the exposed portion is formed. At this time, the insulating core wire 3 and the sheath 2 are naturally required to be flexible.

When the resin coating 8 is formed, each hole 6 of the connector 5 has a gap between the terminals 6 and 4 when the terminal piece 4 is inserted, so that each hole 6 is completely closed. In addition, there is a gap in part, and not all the terminal pieces 4 are inserted (connected) into each hole 6, and some of the holes 6 remain as they are (the terminal pieces 6 are not inserted). In many cases, the molten resin leaks to the connection side opening (the left opening 5a in FIG. 2) of the connector 5 through the hole 6 and the gap. If it leaks out, there is a risk of connection failure of the connector 5.
In order to eliminate these fears, conventionally, a nest is inserted (inserted) into the connector 5 from the connection-side opening 5a of the connector 5, and the gap and the hole 6 are closed with the nest.

Japanese Patent Laid-Open No. 6-283052 JP-A-5-96487

  However, the clearance between the inner surface of the connector 5 and each hole 6 and the insert is extremely small, and the insertion of the insert is troublesome and the workability is deteriorated (impeding automation). On the other hand, if the clearance is made large in order to improve the workability, the molten resin leaks from the clearance and becomes a cause of burrs.

  In addition, since the outer diameter tolerance of the multi-core cable 1 is large (for example, ± 0.1 mm), when the resin coating 8 is molded, if the clearance of the cable clamp portion of the mold is reduced, the cable sheath 2 is removed. The clamp portion is easy to bite, and if it is bitten, the cable 1 (sheath 2) is damaged, resulting in a defective product or an insulation failure. On the other hand, if the clearance is increased, resin leakage from the clamp portion is caused and burrs are generated.

  Resin leakage can be prevented by stuffing an adhesive or a metal molding filling into the gap between the insert and each hole 6, the hole 6 itself, or the gap between the cable 1 and the mold clearance portion. Work is cumbersome and workability is deteriorated (preventing automation).

  In view of the above situation, the present invention allows the coating resin to enter the terminal piece holes 6 and the gaps, and the gaps between the cable 1 and the mold clearance without using inserts or filling. The problem is to prevent it.

In order to achieve the above-described object, the present invention provides an exposed multi-core insulating core wire 3 with a resin having a property of not leaking from a hole in which no terminal piece is inserted before the resin coating 8 is formed. The multi-core connector 5 and the cable sheath 2 end are covered including the periphery, and the resin coating 8 is further formed thereon.
That is, when the melting temperature (melt viscosity) of the molten resin is adjusted, it is found that the molten resin does not leak from the terminal piece hole 6 with its surface tension. It was decided to specify the size and the resin melting temperature. Specifically, the ratio (S1 / S2) of the total area S1 of the hole 6 to the wall area S2 of the hole 6 is 0.5 to 20, and the melt viscosity of the coating resin is 0.5 to 200 Pa · s. It was. Details of S1 and S2 will be described in the following embodiment.

In this case, the molten resin does not leak from the terminal piece hole 6 or the gap due to the surface tension of the molten resin due to the difference between the melt viscosity of the molding material and the area of the hole and the area around it, It does not enter the gap between the cable 1 and the mold clearance. For this reason, the resin coating covering the multi-core connector and the cable sheath terminal including the periphery of the exposed multi-core insulation core wire has the outer shape of the mold cavity without causing a large sink on the surface of the mold. . If the outer shape of this resin coating becomes the required shape, the resin coating formed on the resin coating will not have a large sink on the surface, and will not become a defective product as the outer shape of the mold cavity. That is, a resin coating with good transferability can be obtained.
At this time, considering the actual size of the connector 5, the area of the hole 6 is 4 mm ² or less, and the total area S 2 is 120 mm ² or less.
Note that even if there is a gap between the two pieces 4 and 6 in which the terminal piece 4 is inserted into the hole 6, the gap is much smaller than the hole 6. In addition, there is no leakage from the gap. Similarly, since the clearance (gap) between the cable clamp portion and the cable is much smaller than the hole 6, there is no leakage from the gap.

Of the present invention, the multi-fiber connector having a plurality of terminal pieces holes was fitted in the hole crowded difference multiple insulating end child piece connected to multi-fiber cable to the terminal of the insulated wires having a core wire As a connection structure between a multi-core cable and a multi-core connector, a multi-core insulated core wire is exposed between the end of the cable sheath and the multi-core connector, and around the exposed multi-core insulated core wire. In addition, a resin coating is formed over the multi-core connector and the cable sheath terminal, and the space between the multi-core connector and the cable sheath terminal is blocked, and the resin is further applied over the multi-core connector and the cable sheath terminal via the resin coating. A coating is formed, and the ratio (S1 / S2) of the total area (S2) of the holes to the wall area (S1) of the holes is 0.5 to 20, and the melt viscosity of the first resin coating is A configuration of 0.5 to 200 Pa · s It is possible to use.

  In addition, as a method of forming a connection structure between the multi-core cable and the multi-core connector according to the present invention, a multi-core connector including a periphery of a multi-core insulated core wire exposed between the end of the cable sheath and the multi-core connector is used. A resin coating is formed over the cable sheath terminal to close the gap between the multi-core connector and the cable sheath terminal, and a resin coating is further formed over the multi-core connector and the cable sheath terminal via the resin coating. And the ratio (S1 / S2) of the total area (S2) of the holes to the wall area (S1) of the holes is 0.5 to 20, and the melt viscosity of the first resin coating is 0.5 to 200 Pa · A configuration with s can be employed.

  In the connection structure and the connection method between the multi-core cable and the multi-core connector, the ratio (S1 / S2) is preferably 1 to 20 and the melt viscosity is 1 to 100 Pa · s.

  Various materials can be adopted as the molding material for the resin coating. For example, a thermoplastic resin such as a polyester resin and an adhesive resin and the compound thereof, a polyamide resin and an adhesive resin and the compound thereof, a polyolefin resin and an adhesive Resin and its compound, urethane resin and adhesive resin and its compound, soft vinyl chloride resin and adhesive resin and its compound, vinyl acetate resin and adhesive resin and its compound, ethylene propylene resin Adhesive resins and their compounds, polyester-based liquid crystal polymers and their compounds, etc. Specifically, as adhesive resins, thermoplastic polyester-based adhesive resins such as Aronmelt manufactured by Muromachi Technos, Asahi Tak Chemical Co., Ltd. Examples thereof include thermoplastic rubber-based adhesive resins.

  Various types of multi-core connectors can be used that are suitable for each cable to be used, but the terminal pieces 4 of the insulation core wire 3 are inserted into all the terminal piece holes 6 and any of the insertion holes has a gap. Even if the gap does not occur, there may be a hole in which the terminal piece is not inserted, or there is a hole in the hole in which the terminal piece is inserted and there is a hole 6 that is not inserted. is there.

The multi-core of the multi-core cable means a case having three or more insulated core wires, and the flexible multi-core cable has the flexibility required to be connected to a moving device such as a robot. If necessary, for example, twist the insulation core wires to make a pair, twist the insulation cores, and press and wrap them with tape, place the insulation wires around them and wind them with tape. Then, the outer periphery is covered with a sheath (25 AWG (0.2 mm ² ) × 7P + 22 AWG (0.35 mm ² ) × 6C) heat resistant vinyl insulated heat resistant oil resistant vinyl sheath composite cable, or similar (25 AWG × 6P + 25 AWG × 6C + 22 AWG × 6C) heat-resistant vinyl insulation heat-resistant oil-resistant vinyl sheathed cable or the like is used.

  As described above, the present invention has specified the size ratio of the hole for the terminal piece of the multi-core connector and the property of the coating resin, so that the molten resin for the coating leaks out of the hole and the gap by its surface tension. In addition, since it does not enter the gap between the cable and the mold clearance, the outer shape of the resin coating does not cause large sink marks and the outer shape of the mold cavity is obtained, and further formed on the resin coating. The resin coating does not cause large sink marks on its surface, and has a good transferability with an outer shape that matches the mold cavity.

Action explanatory drawing of one embodiment of this invention Action diagram Action diagram Action diagram The mold for a resin leak test is shown, (a) is a plan view of a lower half mold, (b) is a cut front view, and (c) is a partial external perspective view of a mold cavity. It is the principal part dimension drawing of the metal mold | die, (a) is sectional drawing, (b) is the figure which looked at the through-hole 11c from the right Perspective view of another embodiment

  1 to 4 show an embodiment of the present invention. In this embodiment, a multi-core cable 1 in which 20 insulated core wires 3 are twisted and the twisted multi-core insulated core wires 3 are covered with a sheath 2 is shown. Is connected to a multi-core connector 5 of a resin molded product. First, as shown in FIGS. 1 to 2, the cable sheath 2 is stripped to a required length, and each insulation core 3 is connected to the cable as shown in FIGS. The required length is exposed (exposed), and terminal pieces 4 are provided (crimped) on the exposed ends of the insulated wires 3, and the terminal pieces 4 are inserted into the holes 6 of the multi-core connector 5. Connect the cable 1 to the connector 5. At this time, the hole 6 is a square hole of height: 2.5 mm × width: 1.5 mm.

Next, the multi-fiber connector 5 with the cable 1 is loaded into a mold, and resin 9 (polyester adhesive resin, melting temperature: about 230 ° C., shear rate: about 15000 S ⁻¹ (1 / s )) Was injected at an injection pressure of 0.1 MPa to obtain a multi-fiber connector 5 with cable shown in FIG. At this time, the molten resin did not leak from the hole 6, the gap between the hole 6 and the terminal piece 4, and the gap between the cable sheath 2 and the mold cable clamp portion. The hole 7 was closed by inserting a protruding piece of a mold from the connection side opening side of the connector 5 or attaching a tetrafluororesin tape or the like.
The cable-equipped connector 5 shown in FIG. 3 is further loaded into a mold as in the prior art, and molten resin is injected into the mold, so that the entire outer peripheral surface of the multi-fiber connector 5 (the front opening 5a is formed). 4) and a terminal portion of the cable sheath 2 with a resin coating (for example, a resin name: heat-resistant and oil-resistant vinyl chloride) 8 to form a connection portion in which the resin coating 8 of the cable 1 and the multi-core connector 5 shown in FIG. Got. At this time, there was no leakage of the molten resin 8 from the gap between the cable sheath 2 and the mold cable clamp portion.

In order to specify the property of the molten resin 9 that does not leak from the hole 6 and the size of the hole 6, a mold 10 shown in FIGS.
The mold 10 has the dimensions (unit: mm) shown in FIGS. 5A and 5B, and as shown in FIG. 5C, the cavity 11 includes a flat cavity portion 11a having a thickness of 1 mm, A substantially pyramidal cavity 11b having a cylindrical shape with its tip gradually increased from the end of the cavity 11a, and a cylindrical pool void that communicates from the pyramidal cavity 11b through a through hole 11c. 11d and divided in the middle of the top and bottom. In the figure, 12 is a gate (molten resin injection port).

When the diameter of the through hole 11c in the mold 10 (cavity 11) is d and the diameter of the cylindrical portion at the tip of the pyramidal cavity 11b is D (see FIG. 6), the area S2 of the through hole 11c is d2. ² × π / 4, the tip end area S1 of the pyramidal cavity 11b = D ² × π / 4−S2 (see FIG. 6).
On the other hand, the total area of the terminal piece holes 6 of the connector 5 can be considered as S <b> 2 in the cavity 11, and the wall area having the holes 6 can be considered as S <b> 1 in the cavity 11.

Based on this idea, by attaching the upper and lower central split cores 13 to the mold 10 (cavity 11), different ones of S1 and S2 shown in Table 1 below (No: 1-14 = S1 / S2) : 0.1, 0.5, 0.8, 1.0, 5.0, 10.0, 20.0), and the resin shown in the bottom column of Table 2 below is applied to each mold 10 thereof. The experimental results of injection (injection pressure: 0.1 MPa) are shown in Table 2. Each evaluation in Table 2 is as follows.
"Resin leakage"
X: Resin leak, △: Resin does not leak though it is visible from the hole 6, ○: No resin leak "Transferability"
×: Chipping occurred in the molded product (resin coating 9) and it was not formed according to the dimensions of the mold, Δ: The molded product was the same as the mold shape, but a slight dent was observed, ○: The molded product was a mold "Melting viscosity" made according to shape and dimensions
Measured with a rheometer using an injection molding machine

  From this experimental example, the ratio (S1 / S2) of the total area S1 of the hole 11c to the wall area S2 of the hole 11c is 0.5 to 20.0, and the melt viscosity of the resin coating is 0.5 to 200 Pa · If s, ◯ or Δ is obtained in “Resin leakage” in Table 2, and ○ or Δ is obtained in “Transferability”, there is no leakage of molten resin from the hole 11c. Understandable. Further, in the case of S1 / S2: 1.0 to 20.0 and melt viscosity: 0.5 to 100 Pa · s, all of “resin leakage” and “transferability” are excellent and excellent.

1 and FIG. 2, in each multi-fiber connector 5 of S1 and S2 shown in Table 3 below (6: 30 holes (however, 20 in the drawing)), the resin coating 9 is made of polyester. -Based resin copolymer, melt temperature: about 230 ° C., shear rate: about 15000 s ⁻¹ , melt viscosity: about 100 Pa · s, injection pressure: 0.1 MPa, the molten resin does not leak from the holes 6, The connector 1 with cable 1 of FIG. 3 having excellent transferability was obtained. From this, it can be seen that the area of the hole 6 is preferably 4 mm ² or less and the total area S1: 120 (4 × 30) mm ² or less.

Of course, the cable 1 is not limited to 20 cores and 30 cores, and all the insulated core wires 3 may be connected to the connector 5 (all the terminal pieces 4 are inserted into all the holes 6). However, depending on the specifications, only the necessary insulation core wire 3 may be connected to the connector 5.
In the above-described embodiment, the resin coating 9 is applied to the entire outer peripheral surface of the multi-core connector 5. However, the resin coating 9 may be applied while leaving a part of the outer peripheral surface of the multi-fiber connector 5. Although it is the case of the core connector 5, it goes without saying that the present invention can be adopted even in the case of the male multi-fiber connector 5 'shown in FIG.

Further, the present invention can be applied to a cable other than a cable having high flexibility (flexibility) such as a robot cable. Specifically, as the cable 1 having high flexibility, specifically, a twisted bone by the following evaluation method is used. The measured value of the upper hardness is 80 or less, and the difference between the measured value of the hardness on the twisted bone and the measured value of the hardness of the intermediate portion of the twisted bone and the twisted bone can be 5 or more.
"Evaluation method"
Using the durometer hardness test type A specified in JIS K6253, place the cable on a horizontal iron table and set it so that the tip of the push needle comes over the twisted bone of the insulated wire inside the cable. Press vertically and read the value after 5 seconds, then set the tip of the push needle in the middle part of the twisted bone and the twisted bone, press vertically with about 10N force, and read and evaluate the value after 5 seconds . The number of tests is an average value of 5 times each.

  Incidentally, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

DESCRIPTION OF SYMBOLS 1 Multi-core cable 2 Cable sheath 3 Insulation core wire 4 Terminal piece 5 for connection, 5 'Multi-core connector 6 Hole for terminal pieces of multi-core connector 8 Resin coating 9 Resin coating 10 Mold 11 Cavity

Claims (4)

A multi-core cable (1) having a number of insulated core wires (3) is connected to a terminal of the insulated core wire (3) to a multi-core connector (5, 5 ') having a number of terminal strip holes (6). a connection structure between the fitting and the multi-fiber cable (1) and multi-fiber connector (5,5 ') to the ends of the terminal pieces (4) a difference crowded in the hole (6) which is,
Exposed above multi-core of insulated wire (3) is between the sheath terminal (2) and the multi-fiber connector (5,5 ') of the multi-fiber cable (1), multi-conductor was the exposed of insulated wire (3) the multi-fiber connector, including around the (5,5 ') and the sheath (2) across the terminals resin coating (9) is formed multi-fiber connector (5,5' ) and between the sheath (2) the terminal is closed, the and its resin coating (9) via multi-fiber connector (5,5 ') sheath (2) further resin coating over the terminal (8) The ratio of the total area (S2) of the hole (6) to the wall area (S1) of the hole (6) (S1 / S2) is 0.5 to 20, and the first resin coating is formed. A connection structure between a multi-core cable and a multi-core connector, wherein the melt viscosity of (9) is 0.5 to 200 Pa · s. ^2. The connection structure between a multi-core cable and a multi-fiber connector according to claim 1, wherein the hole (6) has an area of 4 mm ² or less and a total area (S 2) of 120 mm ² or less. A multi-core cable (1) having a number of insulated core wires (3) is connected to a terminal of the insulated core wire (3) to a multi-core connector (5, 5 ') having a number of terminal strip holes (6). a is end child piece (4) the difference crowded by way of making connections between the multi-fiber cable which is fitted into the hole (6) (1) and multi-fiber connector (5,5 '),
The multifiber connector including around exposed above multifiber of insulated wire (3) between the terminal and the multi-fiber connector of the sheath (2) of the multi-fiber cable (1) (5,5 ') (5,5 ') closes between the sheath (2) over the terminal and to form a resin coating (9) multi-fiber connector (5,5' and) and the sheath (2) terminal, the A resin coating (8) is further formed over the multi- core connector (5, 5 ') and the sheath (2) terminal via the resin coating (9), and the entire area (S2) of the hole (6) And the ratio (S1 / S2) of the wall area (S1) of the hole (6) to 0.5 to 20, and the melt viscosity of the first resin coating (9) to 0.5 to 200 Pa · s. A method of connecting a featured multi-core cable and multi-core connector. The method for connecting a multi-core cable and a multi-core connector according to claim 3, wherein the hole (6) has an area of 4 mm ² or less and a total area (S2) of 120 mm ² or less.

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