JP2003180014A - Synthetic resin core for supporting elastic shrinkable tube, and manufacturing method and apparatus thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a synthetic resin core for supporting an elastic shrinkable tube when a connection part of an electric cable is compressively sealed by the elastic shrinkable tube, capable of supporting the elastic shrinkable tube extendedly without damaging it, and being removed smoothly from the elastic shrinkable tube at sealing. <P>SOLUTION: The core is formed cylindrically so that a circular ring string body part in which a synthetic resin string body has previously been wound by one turn in the spiral direction, is connected to the next circular ring string body part sequentially by the engagement of a protruding locking part provided on the facing end surface, and is formed so as to have a thin weld part with which the inner periphery of a joint part is continuously welded to the facing end surface in the spiral direction; the connection part of the electric cable is inserted in the core with the elastic shrinkable tube supported on the core; and the core is released while the protruding locking part is removed from one end side and the thin weld part is continuously separated, thereby sealing the connection part. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical shape for supporting an elastic contraction tube in a radially expanded state when a connecting portion between electric cables is adhered by an elastic contraction force of an elastic contraction tube. The present invention relates to the synthetic resin core, and a method and an apparatus for producing the synthetic resin.

[0002]

2. Description of the Related Art When a straight connecting portion of an electric cable is sealed by an elastic contraction tube, the elastic contraction tube has a smaller diameter than the electric cable. The outer peripheral surface of the core is held in an expanded state, and the linear connecting portion of the electric cable is arranged in the core, and then the elastic shrinkable tube is crimped to the linear connecting portion of the electric cable by removing the core. It is covered with water and dust to protect it.

As the cylindrical core for holding the elastic contraction tube in the expanded state, conventionally, a string-shaped body made of a synthetic resin such as polypropylene or polyethylene is spirally wound and adjacent to each other. Extrusion molding of a structure in which the outer peripheral surface of the joint part of the part is welded in the spiral direction at regular intervals, or a synthetic resin cylindrical body with a plurality of protrusions provided on the inner peripheral surface over the entire length Manufactured in accordance with the present invention, and spirally cut from the outer peripheral surface of the tubular body to a depth reaching the protrusion on the inner peripheral surface so that adjacent ring-shaped cord-like portions are connected only by the protrusion. A cylindrical core or the like is known.

In any of the cores, by pulling the cord-like portion on one end side, the welded portion is divided in the former and the ridge portion in the latter is divided, and the ring-shaped cord-like portion is sequentially pulled out and removed. The elastic contraction tube supported in an expanded state on the outer peripheral surface of the core is elastically contracted by removing the string-like portion, and the connection portion of the electric cable inserted into the core is crimped and sealed.

[0005]

However, in the former core, since the protrusions are formed on the outer peripheral surface by welding, when the thin elastic contraction tube is pressed against the outer peripheral surface and supported in the expanded state, There is a problem that the elastic contraction tube is broken by the protrusions or small holes are formed, resulting in insufficient waterproof and dustproof treatment. Such damage of the elastic contraction tube is caused even when the core is removed, because the projection due to welding is caught on the inner surface of the elastic contraction tube.

On the other hand, in the latter core, the protrusions connecting the ring-shaped cord portions are provided on the inner peripheral surface, so that the above-mentioned problems do not occur, but the extrusion molding is performed. When cutting the tubular body obtained by
If the depth of cut is shallow, the thickness of the protruding portion connecting the cord body portions of the adjacent ring strips becomes large and it becomes difficult to separate the cord body portions of the ring strips from each other. There is a problem that it is extremely difficult to set the depth of cut for the strip. In addition, when separating the cord body parts of the adjacent ring stripes, the protruding parts cannot be easily separated and the linear connection part of the electric cable can be smoothly sealed by the elastic contraction tube. However, there is a problem that the work efficiency is reduced.

The above problems can be solved by providing a welded portion for connecting the cord body portions of the ring strip adjacent to the inner peripheral surface of the former core, but the synthetic resin cord shape It was difficult to spirally wind the body while being separably coupled to each other, and to weld it on the inner peripheral side.

Therefore, the applicant of the present invention filed Japanese Patent Application No. 2000-255.
A synthetic resin core having the structure described in 603 was developed. That is, as shown in FIG. 15, this core has a cord-shaped body portion 51 in which a cord-shaped body 51 made of synthetic resin is first curved into a circular ring shape.
Continuous spiral winding is made in contact with the inner peripheral surface of the hollow mandrel (not shown) with the facing end surfaces of a and this string-shaped body portion 51a and the string-shaped portion 51a curved in a circular ring shape joined. The inner peripheral surface of the joining portion of the adjacent circular ring-shaped cord-shaped portions 51a, 51a is projected to the outer peripheral surface of the heating rotary wheel 61 arranged in one end of the hollow mandrel. The plurality of projections 62 are welded 52 at regular intervals in the spiral direction.

According to this synthetic resin core, it is possible to easily weld the inner peripheral surface of the joining portion of the opposing end surfaces of the circular ring-shaped cord portions 51a, 51a by the heating rotary wheel 61 at the time of manufacturing. When the protrusion 62 of the heating rotary wheel 61 is pressed against the inner peripheral surface of the joint portion of the string-shaped body portions 51a, 51a, a rectangular welded portion 52 corresponding to the cross-sectional shape of the protrusion 62 is formed at the joint portion, The resin portions on the four sides of the welded portion 52 are raised, and the padded portion 52a parallel to the joint end face of the string-like body portions is formed.
And a padding portion 52b that is orthogonal to the joint end surface is formed.

Accordingly, when the circular ring-shaped cord-like body portion 51a of the core is sequentially unraveled while intermittently dividing the welded portion 52 during use, the above-mentioned padding that is orthogonal to the joint end face of the cord-like body portions is formed. When reaching the portion 52b, the padding portion 52
Since b is resistant to fragmentation, smooth unraveling cannot be performed with a constant tensile force, and part of it is separated from the cross section due to the momentary strong tensile force when fragmenting the padding portion 52b. There is a risk that the resin powder may be lost and adhere to the inner surface of the elastic contraction tube to damage the elastic contraction tube.

The present invention has been made in view of the above problems, and an object of the present invention is to smoothly and continuously unravel an elastic contraction tube with a constant small pulling force without damaging the elastic contraction tube and to generate electricity. (EN) It is an object to provide a synthetic resin core that can be attached to a cable, a method for efficiently and accurately manufacturing the synthetic resin core, and an apparatus used for carrying out the method.

[0012]

In order to achieve the above-mentioned object, the invention according to claim 1 receives the inner peripheral surface of the elastic contraction tube over the entire length thereof and the elastic contraction tube in the outer diameter direction. A synthetic resin core that supports in an expanded state, a synthetic resin string-shaped body that is curved in a circular ring shape first, and a string-shaped body that is curved after this string-shaped body portion in a circular ring shape. It is formed into a cylindrical shape by continuous spiral winding in a state where the opposite end faces of the cord-shaped portions are joined, and further, the inner peripheral surface at the joint portion of the opposing end faces of the adjacent circular ring-shaped cord-shaped portions is The structure is such that a thin welded portion is formed by continuously welding in the spiral direction so that the opposing end faces can be separated.

In the synthetic resin core according to claim 1, in the invention according to claim 2, the synthetic resin cord-shaped body is formed in a horizontally long rectangular cross section that is flat in the width direction and has one end surface. The upward locking ridges are integrally formed on the other end surface over the entire length of the downward locking ridges that engage with the upward locking ridges. It is characterized in that a cylindrical core body is formed by spirally winding.

According to a third aspect of the present invention, there is provided a method for producing the synthetic resin core, wherein a synthetic resin string is supplied into the hollow mandrel and slidably contacted with the inner peripheral surface of the hollow mandrel. After curving the circular ring shape in the spiral direction and joining the opposing end surfaces of the cord-shaped body portion curved in the circular ring shape first and the cord-shaped body portion curved in the circular ring shape next to each other, they are placed in the hollow mandrel. By welding the inner peripheral surfaces of the opposing portions joined to each other by the provided welding tool in a continuous spiral shape along the joining end surface, an integrated thin welding portion capable of dividing the joining end surfaces is formed. While rotating in a spiral direction by the rotation driving means disposed in the hollow mandrel, the cylindrical core portion composed of circular ring-shaped cord-like body portions which are sequentially and integrally connected by Characterized in that the feeding from the mandrel in the longitudinal direction.

According to a fourth aspect of the present invention, there is provided an apparatus for carrying out the method for producing a synthetic resin core, comprising:
One end has an inlet for introducing a synthetic resin string-like body, and the introduced string-like body is in contact with an inner peripheral surface of the circular one end to be curved in a circular ring shape and one of the curved string-like body portions. A hollow mandrel provided with a vertical spiral pressing end surface that pushes the end surface and pushes it in the spiral direction toward the other end side while joining it to the string-shaped body portion curved in the shape of a circular ring first, and this hollow mandrel The inner peripheral surface of the joining portion of the cord-shaped body portion curved in the shape of a circular ring and the cord-shaped body portion curved in the shape of a circular ring is disposed in one end and is continuously welded in the spiral direction. A welding tool that forms a thin welded portion that can separate the opposing end faces, and a cylindrical core portion that is a circular ring-shaped cord-like body portion that is integrally connected in a spiral winding sequence by this welding. Along the circumference towards the other end It is constituted by a rotary drive means for moving while rotating the spiral.

In this synthetic resin core manufacturing apparatus, the invention according to claim 5 is such that the welding tool is rotated by heating in contact with the inner peripheral surface of the joint portion of the cord-shaped body portion curved in a circular ring shape. It is characterized in that the outer peripheral surface of the ring is provided with a circular outer peripheral edge portion for welding the inner peripheral surface of the joint portion in a continuous spiral shape.

Further, in the invention according to claim 6, the rotation driving means is composed of a plurality of rotary cords that rotate about the respective axes in the same direction at the same speed and at the same time. One end of the rotary cord is disposed in a groove that is recessed in the inner peripheral surface of the hollow mandrel at regular intervals in the circumferential direction and is inclined in the spiral direction from one end to the other end, A part of the outer peripheral surface projecting from the groove is brought into sliding contact with the outer peripheral surface of the cylindrical core portion to rotate the core portion.

[0018]

[Function] The synthetic resin core that holds the elastic contraction tube in an expanded state is formed into a cylindrical shape by spirally winding a synthetic resin string-like body while curving it into a circular ring shape,
Moreover, since the adjacent circular ring-shaped cord portions are welded at the joint portion on the inner peripheral surface side by the thin-walled welded portion, no protrusion due to welding is formed on the outer peripheral surface, so that the elastic shrinkable tube is formed. There is no risk of damaging or damaging the.

By inserting the linear connecting portion of the electric cable into the core and unwinding the circular ring-shaped cord portion of the core from the end side, the joint portions of the circular ring-shaped cord portion are connected. Since the welded part is thin and is continuously provided in the spiral direction, simply pulling the welded part with a small constant tensile force makes it possible to move lightly and over the entire length without causing partial defects. Can be continuously divided. When the string-shaped part is removed, the elastic shrink tube shrinks from the end side and is crimped to the electric cable, and when the core is completely disassembled and removed, the entire outer peripheral surface of the connection part of the electric cable is removed. It will be in a state of being crimped and sealed.

The removal work of the core is performed by previously unraveling the circular ring-shaped cord-like body portion of the other end of the core exposed from the other end of the elastic contraction tube and pulling it out to the one end side through the inside of the core. The pulled-out string-like body portion is pulled, and the circular ring-like string-like body portion on the other end side is sequentially removed while the welded portions fixed to each other are divided by the tensile force.

According to a second aspect of the present invention, the core has a structure in which joining end faces of adjacent circular ring-shaped cord portions are locked by an upward locking ridge and a downward locking ridge. By placing them, the circular ring-shaped cord-like body parts forming the core are sequentially and accurately connected in the same shape in the length direction and the circumferential direction of the core, and the outer peripheral surface of the adjacent circular ring-shaped cord-like body parts However, the elastic contraction tube can be pressure-bonded with a uniform pressure-bonding force continuously over the entire length and in a uniform state.

Further, when unraveling the circular ring-shaped cord-like body portion that constitutes the core, an upward locking protrusion is provided on one end face side of the circular ring-shaped cord-like body portion to be unraveled first. By keeping the downward locking ridges to be released next to the upward locking ridges and pulling the circular ring string part inward toward the core, the upward locking ridges The core is smoothly disassembled while being easily and automatically released from the locking ridge.

In order to obtain such a synthetic resin core for supporting an elastic contraction tube, as described in claims 3 and 4, one end of the hollow mandrel is opened in the tangential direction of the hollow mandrel. When the synthetic resin string-like body is fed to the inlet, the end face of the hollow mandrel facing the one end of the hollow mandrel out of both end faces (side end faces in the lengthwise direction) of the string-like body parallel to each other. A circular ring formed by the circular inner surface of one end of the hollow mandrel, which is in contact with a vertical pressing end surface that is spirally inclined and is pushed toward the other end in the spiral winding direction. It is curved in a circular shape and moves spirally toward the other end side by a pitch corresponding to the width of the cord-like body when it makes a round along the above-mentioned spirally inclined vertical pressing end face, and at the same time as the other end face (length Directional Side end face) is joined to one end surface of the previously formed in a circular ring shape in a spiral direction the string-like body portion.

At this time, an upward locking protrusion is provided on one end surface side of the string-shaped body, and a downward locking projection strip is provided on the other end surface side of the string-shaped body. The downwardly projecting locking ridges of the cord-shaped body portion to be introduced next to the locking ridges are engaged, and the adjacent circular ring-shaped cord-shaped body portions are continuously connected in the spiral direction by these upper and lower locking ridges. Then, the inner and outer peripheral surfaces are connected to each other in a lengthwise direction to form a core. Further, the inner peripheral surfaces of the joint portions of the adjacent circular ring-shaped cord-like body portions are continuously welded in a spiral direction with a constant width by a welding tool disposed in one end of the hollow mandrel, and adjacent circular rings are attached. A spiral band-shaped thin welded portion is formed by integrally connecting the cord-shaped body portions.

The formation of the circular ring-shaped cord in the one end of the hollow mandrel is performed by feeding the synthetic resin cord from the inlet and contacting the inner peripheral surface of the one end of the hollow mandrel by the pushing force in the longitudinal direction. And is curved into a circular shape, and is pushed toward the other end by the vertical pressing end surface inclined in the spiral shape. And, the cylindrical core portion composed of circular ring-shaped cord-like body portions sequentially connected integrally in the lengthwise direction by the above-mentioned welding is a hollow mandrel while being rotated in a spiral direction by a rotation driving means arranged in the hollow mandrel. Is sent out in the length direction to form a long core. As the rotation driving means, a plurality of rotary cords that rotate in contact with a plurality of outer peripheral surfaces of the core portion formed in the hollow mandrel can be used.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a concrete embodiment of the present invention will be described with reference to the drawings. In FIG. 1 and FIG. 2, a synthetic resin core A is made of polypropylene, polyethylene or polyvinyl chloride. Cylindrical shape with a certain thickness formed to a predetermined inner diameter and outer diameter by continuously bending a synthetic resin string 1 having a relatively hard and moderate strength and flexibility into a continuous spiral shape Is formed in.

More specifically, the cord-shaped body 1 is formed at a constant length into a cord-shaped body portion 1a curved in a circular ring shape in the spiral direction, and the circular ring-shaped cord-shaped body portions 1a are successively adjoined. The strip-shaped body portions 1a, 1a has a structure in which opposite end faces are separably joined and connected, and the inner peripheral surface of the joined portion has a small width with the joining end face of the string-shaped body portions 1a, 1a as the center. A thin welded portion 2 having a constant width is continuously formed in the same spiral direction along the joint portion, and the thin welded portion 2 has a central portion in the width direction, that is, a circular ring-shaped cord portion 1a, It prevents the circular ring-shaped cord-shaped body portion 1a from being unraveled from the end portion side of the core 1 by the ultra-thin cord-shaped thin welded portion 2a in which the inner peripheral corners of the joint end surface of 1a are integrated. The core 1 is configured to maintain a cylindrical shape. In the figure, reference numerals 2b and 2b denote resin ridges raised on both sides of the thin welded portion 2 when the thin welded portion 2 is formed, and are formed between the circular ring-shaped cord portions 1a and 1a. The thin welded portions 2 are formed in a continuous spiral shape on both sides of the inner surface of the joint end surface so as to be parallel to each other, and between these ridges 2a, 2a.

As shown in FIGS. 1 and 3, the length of the synthetic resin core A is longer than that of the elastic contraction tube B, and the elastic contraction tube B is expanded on the outer peripheral surface thereof in the outer diameter direction. In the form of being supported by both ends, both ends of the core A project outward from both ends of the elastic contraction tube B. Further, the inner diameter of the elastic contraction tube B when the elastic contraction tube B is completely contracted is smaller than the outer diameter of the electric cable C to be covered, and the connecting portion C1 of the electric cable C is
While the outer peripheral surface of the synthetic resin core A is formed to be crimped by its contracting force, the inner diameter of the synthetic resin core A is sufficiently larger than the outer diameter of the electric cable C. It is configured such that a relatively wide void portion D is formed between the outer peripheral surfaces of the electric cable C.

As shown in FIG. 2, the synthetic resin string-like body 1 constituting the core A is formed in a horizontally long rectangular shape having a flat cross section, and both ends parallel to each other along the length direction thereof. In the surface (both end surfaces), an upward locking protrusion 3 having an L-shaped cross section is continuously provided on the lower half of one end surface over the entire length, and an inverted L-shaped cross section is provided on the upper half of the other end surface. The downward locking protrusions 4 each have a shape protruding continuously over the entire length. Specifically, the upward locking projections 3 are formed from the lower half of the string-shaped body 1 to the string-shaped body 1.
Horizontal protrusion that protrudes a certain width in the direction that extends the width of the
3a and a vertical protruding piece 3b having a constant height protruding upward from the protruding end of the horizontal protruding piece 3a. The vertical protruding piece 3b and one end surface of the cord-shaped body 1 A narrow locking groove 3c that opens upward is formed between the two.

Similarly, the downward locking protrusion 4 has a horizontal protrusion 4a protruding from the upper half of the other end of the cord 1 in a direction extending the width of the cord 1 and a horizontal protrusion 4a. Horizontal protrusion
The vertical projecting piece 4b and the string-shaped body 1 are composed of a vertical projecting piece 4b having a constant height and projecting downward from the projecting end of 4a.
A narrow engaging groove 4c that opens downward is formed between the other end surface and the other end surface.

The adjacent circular ring-shaped cord-like body portions 1a constituting the core A, which are adjacent to each other, are joined to each other at the opposing end faces of the circular ring-shaped cord-like body portion 1a. The upward locking ridges 3 are connected to each other by engaging the downward locking ridges 4 protruding from the other circular ring-shaped cord-shaped body portion 1a, and the core A is connected by this connection. It has a cylindrical shape that does not lose its shape and does not accidentally divide the thin welded portion 2 by pulling or radial crushing force. In the state where the cord-shaped body 1 is curved into the circular ring-shaped cord-shaped body portion 1a, the upward locking ridge 3 is an outward locking ridge, and the downward locking ridge 4 is an inward locking ridge. It is a stop ridge, and the vertical protruding piece 3b of the outward locking ridge 3 is outside the vertical protruding piece 4b of the inward locking ridge 4 in the locking groove 4c of the inward locking ridge 4. It is fitted and locked in the locking groove 3c of the direction locking projection 3.

Next, the usage of the synthetic resin core A constructed as described above will be explained. First, as shown in FIG. 1, an elastic contraction tube B is crimped to the outer peripheral surface of the core A in an expanded state. The elastic contraction tube B is supported by the core A in an expanded state. In addition, core A
Has a dimension longer than the length of the elastic contraction tube B, and both ends thereof are projected from the elastic contraction tube B by a predetermined length.

One electric cable C to be connected to the elastic contraction tube B is inserted and the electric cable C is inserted.
And the other electric cable C, the electric wire coating layers C2 and C2 are connected to each other by exposing the conductive wires exposed by peeling off the ends of the electric wire covering layers C2 and C2.
C1 is located inside the center of Core A, as shown in FIG. Further, the core A has, on one end side thereof, a circular ring in which the downward (inward) locking protrusion 4 of the circular ring-shaped cord body portion 1a on the most end side is adjacent to the circular ring-shaped cord body portion 1a. While being locked to the upward (outward) locking ridge 3 of the cord-shaped body portion 1a, the other end side is directed upward (outward) of the circular ring-shaped cord portion 1a on the extreme end side. The locking ridge 3 is in a state of being locked to the downward (inward) locking ridge 4 of the circular ring-shaped cord body portion 1a adjacent to the circular ring-shaped cord body portion 1a.

Therefore, on the other end side of the core A,
Adjacent circular ring-shaped cord portions 1a, 1a are sequentially removed while the locking projections 3, 4 engaging with each other are removed, and the thin welded portion 2 is removed.
The structure is such that it can be unraveled toward the hollow inside of the core A while sequentially separating the core A, and the circular ring-shaped cord-like body portion 1a at the other end of the core A is previously loosened by several rings. The inside of the hollow is linearly drawn to one end side, and the tip portion thereof is in a state of protruding from one end of the core A to the outside.

In this state, pulling the tip of the cord-like body portion protruding outside through the hollow of the core A,
As shown in FIG. 4, the circular ring-shaped cord-shaped body portion 1a is sequentially arranged from the other end side of the core A, and the upward (outward) locking protrusions 3 are formed on the next circular ring-shaped cord-shaped body portion 1a. While being disengaged from the downward (inward) locking projections 4, and the thin welded portion 2 is cut into a sheared state, the thin welded portions 2 are sequentially unraveled and pulled out to the other end side of the core A. At this time, the thin welded portion 2 is continuous in the spiral direction over the entire length of the joining portion with a thin constant thickness on the inner peripheral surface of the joining portion between the string-like body portions 1a, and at the center portion in the width direction thereof. Since the circular ring-shaped cord-shaped body portions 1a, 1a are integrally connected by the ultra-thin cord-shaped thin welded portion 2a, by pulling the tip of the cord-shaped body portion 1a with a small constant tensile force, It is possible to easily and uniformly divide the ultra-thin string-shaped thin welded portion 2a of the welded portion 2 over the entire length.

In this way, when the core A is sequentially unwound from the circular ring-shaped cord portion 1a from the other end to the one end, the elastic contraction tube B supported by the core A is circularly ring-shaped cord portion 1a. As shown in FIG. 4, first, the other end portion is crimped onto the insulation coating layer C2 of the other electric cable C by the elastic contraction force in accordance with the cancellation of the above, and then the central portion is crimped onto the connection portion C1 between the cables. Then, when the core A is completely removed, the entire length reaching one end is crimped onto the insulation coating layer C2 of one electric cable C as shown in FIG. 5 to waterproof the connecting portion C1 of the electric cables C and C. , It is a dustproof seal.

Next, a manufacturing apparatus and a manufacturing method for the synthetic resin core A will be described. As shown in FIGS. 6 to 9, the manufacturing apparatus has an inlet 13 (shown in FIG. 9) for introducing the synthetic resin string 1 at one end, and the introduced string 1 is at one end. A circular ring-shaped cord-shaped body portion 1a preceded by a circular ring-shaped cord-shaped body portion 1a which is curved by a circular ring-shaped inner peripheral surface and presses one end surface (one end surface) of the curved cord-shaped body portion 1a toward the other end side. A hollow mandrel 10 provided with a ring member 11 having a vertical spiral pressing end surface 12a that pushes in a spiral direction toward the other end while joining the end surfaces (opposite end surfaces) facing the ring-shaped cord portion 1a to each other. , The hollow mandrel 10 is disposed in one end of the hollow mandrel 10 and is connected to the inner peripheral surface of the joining portion 1a that is curved in the shape of a circular ring and the string portion 1a that is curved in the shape of a circular ring. Welding tool 20 (shown in FIG. 7) that spirally welds, and welding 2 by this welding tool 20 Therefore, the rotation is performed by moving the cylindrical core portion, which is formed by circular ring-shaped cord-like body portions that are integrally connected in the spiral direction, along the inner peripheral surface of the hollow mandrel 10 toward the other end while rotating spirally. It is composed of a driving means 30.

The ring member 11 provided at one end of the hollow mandrel 10 has an inner diameter slightly smaller than the inner diameter of the hollow mandrel 10 and is arranged on the same center line as the hollow mandrel 10. An outer ring member fixedly attached to its one end face with its opposite end face abutting.
11A and an inner ring member 11B fitted to the inner peripheral surface of one end of the outer ring member 11A.

The inner ring member 11B is a flange portion fixedly attached to one end surface of the outer ring member 11A.
11b1 is provided with a ring portion 11b2 projectingly inserted into one end portion of the outer ring member 11A, and the outer peripheral surface of the ring portion 11b2 is cut into an L-shaped cross section at a depth corresponding to the thickness of the cord-shaped body 1. A distance corresponding to the width of the string-shaped body 1 while the string-shaped body 1 introduced from an introduction port 13 described later makes one round while curving from the upper end of the vertical one end surface formed by the notch and the notch. Only the circularly curved cord-shaped body portion 1a is formed on the pressing end surface 12a that is spirally inclined so as to push it toward the other end side.

Further, the outer peripheral surface of the ring portion 11 of the inner ring member 11B and the outer ring member which are notched in an L-shaped cross section.
The inner peripheral surface of 11A forms an annular space 12 that opens toward the other end of the outer ring member 11A, and the inner peripheral surface of the inner ring member 11B with respect to the outer peripheral surface of the ring portion 11 is formed. An introduction port 13 of the cord-like body 1 is formed which communicates with the upper end of the annular space 12 in a tangential direction from the outer side, and a vertical wall on one end side of the introduction port 13 is vertically inclined by the spiral shape. The pressing end surface 12a is continuously provided on the upper peripheral end. The hollow mandrel 10 having the ring member 11 is installed and fixed in a horizontal state on the machine base 5.

On the other hand, as shown in FIG. 12, the inner peripheral surface of the hollow cylindrical mandrel 10 is slightly spirally inclined from one end to the other end of the hollow mandrel 10 at regular intervals in the circumferential direction. .. having a C-shaped cross section are recessed. The inclination angle of the inclined groove 14 in the circumferential direction with respect to the axial direction of the hollow mandrel 10 is such that the vertical pressing end surface 12 is inclined in the spiral direction with respect to the axial direction of the hollow mandrel 10.
It is formed equal to the inclination angle of a. That is, each inclined groove 14 is oriented in a direction perpendicular to the pressing end surface 12a.

Although the hollow mandrel 10 may be formed from a single cylindrical body, the inner peripheral surface of the hollow mandrel 10 has a guide groove 12 which is inclined in the spiral direction from one end to the other end as described above.
Since it is technically difficult to drill the
As shown in Fig. 5, the annular member 10A having a constant thickness is provided with holes 14a having a C-shaped cross section, a part of which is opened on the inner peripheral surface of this member, at regular intervals in the circumferential direction and on both front and rear end surfaces of the annular member 10A. Are provided parallel to the axial direction of the hollow mandrel 10, and a plurality of annular members 10A are superposed in series and sequentially fixed in a state in which they are slightly displaced in the circumferential direction to form a series. The inclined groove 14 is formed by the hole 14a.

In each inclined groove 14, one end of a flexible cord 31 formed by winding a metal wire in a coil shape is attached to the inclined groove 14 at a part of its peripheral surface. The hollow mandrel (10) is rotatably disposed in the inclined groove (14) in a protruding state. In addition, the protruding size of a part of the cord 31 protruding from the inclined groove 14 is from the inner peripheral surface of the hollow mandrel 10 to the inner peripheral surface of the outer ring member 11A having a diameter slightly smaller than the inner peripheral surface. Therefore, the outer peripheral surface of the projecting portion of the cord body 31 is slid on the outer peripheral surface of the circular ring-shaped cord-shaped body portion 1a sent to the hollow mandrel 10 side along the inner peripheral surface of the outer ring member 11A. The core portion composed of the circular ring-shaped cord-like body portions 1a that are in contact with each other and are continuous in series is moved toward the other end of the hollow mandrel 10 while rotating in the spiral direction.

As shown in FIG. 7, each cord 31 is pulled out from the hollow mandrel 10 and expanded outward, and the cord is driven to rotate on the machine base 5 so as to face the hollow mandrel 10. The mechanism 40 is configured to be simultaneously driven to rotate in the same direction. The cord rotation drive mechanism 40 employs a known means for simultaneously rotating the gears whose central portions are fixed to the ends of the cords 31 in the same direction by the motor drive via the meshing gears.

Further, the welding tool 20 arranged in one end of the hollow mandrel 10 has a heating rotary wheel 21 formed by projecting a small circular outer peripheral edge portion 21a on the outer peripheral surface as shown in FIGS.
The heating rotary wheel 21 is rotatably supported at its tip by a cylindrical shaft 23 and a heater (not shown) for heating the rotary wheel 21 through the cylindrical shaft 23. The direction of rotation is directed toward the spiral movement direction of the joining portion of the circular ring-shaped cord-like body portions 1a, 1a which are joined to each other and which are formed by the guide groove 12 provided in the ring member 11 of the hollow mandrel 10 and its circular outer peripheral edge portion. 21a is slidably in contact with the inner peripheral surface of the joint portion and the heating rotary wheel 21 is rotated by the frictional force due to the rotation of the circular ring-shaped cord portion 1a in the spiral direction, while the preceding circular ring-shaped cord portion 1a is rotated. And the following circular ring-shaped cord part
The inner peripheral surface of the joint with 1a is continuously welded 2 in the longitudinal direction of the joint.

Reference numeral 6 denotes a cord-like body supply device installed on the machine base 5 outside the ring member 11 of the hollow mandrel 10, and the rotational force of the cord-like body 1 is sandwiched between the pair of upper and lower rolls 6a and 6b. To continuously and forcibly feed the string-like body 1 into the above-mentioned inlet of the ring member 11,
By the feeding force, the cord 1 is curved in contact with the inner peripheral surface of the outer ring member 11A as described above, and the curved circular ring-shaped cord portion 1a is vertically inclined in the spiral shape of the inner ring member 11B. The pressing end face 12a pushes toward the rotation drive means 30 side (the other end side).

In order to manufacture the core A by the manufacturing apparatus having the above-described structure, the synthetic resin cord-shaped body 1 having a horizontally long rectangular cross section is fed from the feeding device 6 into the inlet 13, and the cord-shaped body is produced. Reference numeral 1 designates an annular space portion in a ring member 11 which is continuous with one side wall of the inlet port 13 while one end surface (one end surface) protruding from the upward locking projection 3 is in sliding contact with the side wall.
The annular space portion 12 is in contact with the inclined starting end portion (upper end portion) of the above-mentioned spirally pressing vertical pressing end surface 12a at one end portion of 12
It is fed into the inside, and due to the feeding force, it contacts the inner peripheral surface of the outer ring member 11A and is curved into a circular ring shape.

At this time, the cord-like body 1 is pushed inside the annular space 12 toward the other end side of the outer ring member 11A by the vertical pressing end surface 12a inclined in the spiral shape, and in this state, the pressing end surface is moved to one side. When the cord-shaped body portion 1a formed in a circular ring shape by rotating reaches the upper end of the other end side, which has a distance approximately equal to the width of the cord-shaped body 1 from the guide groove 12, The protruding upward locking ridges 3 are engaged with the downward locking ridges 4 protruding from the other end surface of the string-like body 1 continuously supplied through the introduction passage 13. .

In this way, the preceding circular ring-shaped cord portion 1a and the subsequent circular ring-shaped cord portion 1a are engaged and connected with each other by the locking ridges 3 and 4, and then these circular ring-shaped cord portions 1a are connected. The inner peripheral surface of the joint portion of the body portions 1a, 1a is continuously welded in the spiral direction along the joint portion by the circular outer peripheral edge portion 21a of the heating rotary wheel 21 which is rotated by the sliding contact force with the inner peripheral surface. To be done.

Specifically, the circular outer peripheral edge of the heating rotary frame 21
Circular ring-shaped cord portion where outer peripheral surfaces of 21a are joined to each other
The welded portions 1a and 1a are pressed against each other with the central portion in the width direction being positioned on the inner peripheral surface of the joined portion to continuously form a thin welded portion 2 having a width equal to the width of the circular outer peripheral edge portion 21a on the joined portion. To be done. At this time, in the joint end surfaces of the circular ring-shaped cord-shaped body portions 1a, 1a, the inner peripheral side corner portions facing each other are melted and
As shown in FIG. 3, the cord-shaped welded portion 2a is extremely thin and thin, and the cord-shaped welded portion 2a has a structure in which the circular ring-shaped cord-shaped body portions 1a, 1a are integrally connected and connected in a separable manner. In addition, on both sides of the thin welded portion 2, there are parallel ridges 2b and 2b in which the synthetic resin rises due to melting of the inner peripheral surface of the joint portion of the string-like body portions 1a and 1a, with the joint end surface being the center and both sides thereof. It is formed in a continuous spiral shape.

As described above, the cord-like body portion 1a which is curved in the shape of a circular ring first along the guide groove 12 and the cord-like body portion 1a to be supplied next are locked to each other by the locking projections 3 thereof. While being engaged with each other, they are sequentially curved into a circular ring shape as shown in FIG. 13, and the inner peripheral surface of the joint is heated by a heating rotary wheel.
The circular outer peripheral edge portion 21a of 21 is welded 2 in a continuous spiral shape to integrally connect the inner peripheral portions of the joining facing surfaces of the string-like body portions 1a and 1a, and the circular ring-like string-like body portions 1a and 1a are joined together. The outer ring member 11 while forming the core A continuously spirally one after another
The inner peripheral surface of the other end of A is brought into sliding contact with the outer peripheral surface of the A, and it moves toward the other end while rotating in the spiral direction.

Further, the core portion introduced into the hollow mandrel 10 is rotated in the spiral direction by a plurality of filaments 31 which rotate in contact with the outer peripheral surface of the core portion, while rotating from the other end of the hollow mandrel 10 to the hollow mandrel 10. It is sent out in the extension direction of 10 to form a long core A. Thus
The manufactured long core A is cut into a predetermined length to be a synthetic resin core for supporting the elastic contraction tube B.

In the above embodiment, the rotation driving means 30 for the core A formed in the hollow mandrel 10 is used.
A plurality of rotary cords 31 that rotate in contact with the outer peripheral surface of the core A are used as the core A. However, a plurality of rotary rollers are inserted from one end side of the ring member 11 of the hollow mandrel 10 to rotate the same. The roller may be rotated in contact with the inner peripheral surface of the core A formed in the hollow mandrel 10, and the welding may be performed by welding the inner peripheral surfaces of the adjacent circular ring-shaped cord-shaped body portions 1a, 1a. Ultrasonic welding may be used as the tool 20.

Further, adjacent circular ring-shaped cord portions
As the engaging structure between 1a and 1a, an upward locking ridge 3 having an L-shaped cross section and a downward locking ridge 4 having an inverted L-shaped cross section are formed, as shown in FIG. It may be formed by the inclined end surfaces 3A and 4A which are joined to each other as shown in the drawing, and as shown in (b), (c) and (d) of FIG. An inclined end surface 3B having
It may be formed in 4B. Further, as described above, the circular ring-shaped cord portions 1a, 1a can be welded to each other on the inner peripheral surface of the joint portion at small intervals to maintain the shape of the cylindrical core A. As shown in the figure (e),
It may be formed on the vertical end faces 3C and 4C.

[0055]

As described above, according to the synthetic resin core for supporting the elastic contraction tube of the present invention, the cord-shaped body made of the synthetic resin is first curved into a circular ring shape, and the cord-shaped body. It is formed into a cylindrical shape by continuous spiral winding in a state where the facing end surface of the cord-shaped portion which follows the portion and is curved in the shape of a circular ring is joined, and the adjacent circular-ring-shaped cord portions face each other. Since the inner peripheral surface at the end face joint is continuously integrated by the thin welded part over the entire length, there is no protrusion due to welding on the outer peripheral surface. There is no risk of damaging or damaging the tube, and it is possible to reliably seal the connection part of the electric cable,
Since the welded portion connecting the joints of the circular ring-shaped cord-like body portion is thin and is continuously provided in the spiral direction on the inner peripheral surface of the jointed portion, the welded portion has a small constant size. By simply pulling with a pulling force, it can be divided lightly and continuously over the entire length without causing partial loss, etc., and the sealing work can be done efficiently and accurately without damaging the elastic shrinkable tube. Is.

According to the second aspect of the invention, the joining end surfaces of the adjacent circular ring-shaped cord portions are locked by the upward locking projections and the downward locking projections. Therefore, the circular ring-shaped cord-like body portions forming the core are sequentially and accurately connected in the same shape in the length direction and the circumferential direction of the core. The outer peripheral surface maintains a continuous shape in a flush state, exerts a uniform supporting force over the entire length, and the elastic contraction tube can be crimped with a uniform crimping force over the entire surface.

Further, when unraveling the circular ring-shaped cord-like body portion which constitutes the core, an upward locking projection is arranged on one end face side of the circular ring-shaped cord-like body portion to be unraveled first. By keeping the downward locking ridges to be released next to the upward locking ridges and pulling the circular ring string part inward toward the core, the upward locking ridges The core can be smoothly disassembled while being easily and automatically disengaged from the locking ridges, and the work of sealing the connection part of the electric cable with the elastic contraction tube can be performed more efficiently.

Further, as the core manufacturing method and manufacturing apparatus, as described in claims 3 and 4, a synthetic resin cord-like body is introduced into the hollow mandrel from an inlet provided at one end of the hollow mandrel. By supplying the cord-shaped body portion, it can be moved in the circumferential direction while slidingly contacting the inner peripheral surface of the hollow mandrel and accurately curved into a circular ring shape, and one end surface of the cord-shaped body is hollow. Since it moves in the circumferential direction toward the other end side while making sliding contact with the vertically pressing spirally inclined pressing end face formed in one end of the mandrel, the width of the string-like body when making one turn along this pressing end face. It is moved spirally toward the other end side by a pitch corresponding to, and is securely joined to one side surface of the string-like body part that has made one round around the other end face of the string-like body part that is continuously introduced next. While making the Over a can be accurately formed.

At this time, by providing an upward locking ridge on one end face side of the cord-like body and a downward locking ridge on the other end face side, the cord-like body portion which has made a spiral turn upwards is directed upward. The downward locking projections of the string-like body portion to be introduced next to the locking projections are securely engaged, and the adjacent circular ring shapes are integrally connected by these vertical locking projections so that the inner and outer peripheral surfaces are Each of the cores can be formed so as to be flush with each other in the lengthwise direction, and the welding tool is arranged in one end of the hollow mandrel. Ultra-thin uniform thickness in which the inner peripheral surface of the joint portion of the cord-like body portion is continuously welded in the spiral direction and the joint end surfaces are integrated with the inner peripheral portion of the joint end surface of the circular cord body portion. The thin welded parts of the The core formed by detachably connecting a grayed-shaped string-like body portion can be efficiently produced.

In addition, the cylindrical core portion, which is formed by sequentially connecting the circular ring-shaped cord portions, is rotated in the spiral direction by the rotation driving means arranged in the hollow mandrel, so that it is continuously manufactured. It is possible to efficiently produce a long core while smoothly pulling out the obtained core from the inside of the hollow mandrel at a constant speed in the longitudinal direction.

[Brief description of drawings]

FIG. 1 is a perspective view of a synthetic resin core covering an elastic contraction tube,

FIG. 2 is a partially enlarged sectional view of a synthetic resin core,

FIG. 3 is a partially cutaway perspective view showing a state in which a connection portion of an electric cable is inserted,

FIG. 4 is a perspective view showing a state in which an elastic contraction tube is attached to a connection portion of an electric cable,

FIG. 5 is a perspective view showing a state in which an elastic contraction tube is attached to a connection portion of an electric cable,

FIG. 6 is a simplified vertical sectional side view of a synthetic resin core manufacturing apparatus.

FIG. 7 is a partially cutaway vertical side view thereof,

FIG. 8 is a simplified vertical sectional side view of a ring member,

FIG. 9 is a simplified vertical sectional front view thereof,

FIG. 10 is a simplified front view of the entire apparatus,

FIG. 11 is a vertical cross-sectional side view showing a state where a circular ring-shaped cord-like body portion is formed,

FIG. 12 is a front view thereof,

FIG. 13 is a simplified perspective view thereof,

FIG. 14 is a cross-sectional view showing an engaging structure of a circular ring-shaped cord body portion;

FIG. 15 is a perspective view showing a state where the inner peripheral surface of the circular ring-shaped cord-like body portion is intermittently welded.

[Explanation of symbols]

A synthetic resin core B Elastic shrink tube C electric cable C1 connection 1 Synthetic resin string 1a Circular ring-shaped cord 2 Thin wall weld 2a Ultra-thin string-shaped thin welded part 3 Upward locking protrusion 4 Downward locking ridge 10 hollow mandrel 11 Ring member 12 Guide groove 20 Welding tool 22 Circular outer peripheral edge 30 rotation drive means 31 striatum

Claims (6)

[Claims] 1. A synthetic resin core for receiving the inner peripheral surface of an elastic contraction tube over its entire length and supporting the elastic contraction tube in a state where the elastic contraction tube is expanded in the outer diameter direction, the string being made of synthetic resin. By continuously spirally winding the strip-shaped body in a state where the facing end faces of the string-shaped body portion curved in the shape of a circular ring first and the string-shaped portion subsequently curved in the shape of a circular ring are joined. It is formed in a cylindrical shape, and further, a thin welded portion capable of separating the opposing end faces by continuously welding the inner peripheral surfaces in the joining portions of the opposing end faces of the adjacent circular ring-shaped cord-like parts in a spiral direction. A synthetic resin core for supporting an elastic contraction tube characterized by being formed. 2. The cord-like body is formed in a rectangular shape having a laterally long cross section, and one end of each of the end faces that are parallel to each other in the lengthwise direction has an upward locking projection, and the other end of the string has a locking projection. Each of the downward locking projections that stop is integrally formed over the entire length, and a cylindrical core body is formed by continuously spirally winding while locking the locking projections. The synthetic resin core for supporting the elastic contraction tube according to claim 1. 3. A synthetic resin string-like body is fed into a hollow mandrel, and while being slidably in contact with the inner peripheral surface of the hollow mandrel, is curved in a circular ring shape in a spiral direction and is first curved in a circular ring shape. After joining the opposing end surfaces of the cord-shaped body portion and the cord-shaped body portion which is then curved in a circular ring shape to each other, the inner peripheral surfaces of the opposed portions joined to each other by the welding tool disposed in the hollow mandrel are A circular ring-shaped cord-like body portion that is integrally connected in the longitudinal direction by this welding to form a thin welded portion that is integrally separable between the welded end surfaces by welding in a continuous spiral shape along the welded end surface. The synthetic resin core is characterized in that the cylindrical core part consisting of is sent out in the length direction from the hollow mandrel while being rotated in the spiral direction by the rotation driving means arranged in the hollow mandrel. A method of manufacturing. 4. A cord which has an introduction port for introducing a synthetic resin string-like member at one end and which is bent into a circular ring shape by being in contact with the inner peripheral surface of the circular one end. A hollow mandrel provided with a vertical spiral pressing end surface that pushes one end surface of the strip-shaped body portion and joins it to the string-shaped body portion curved in a circular ring shape first, and pushes it in the spiral direction toward the other end side. , The spiral mandrel is provided on the inner peripheral surface of the joint between the string-shaped body portion curved in the shape of a circular ring and the string-shaped body portion curved in the shape of a circular ring, which is disposed in one end of the hollow mandrel. A welding tool that continuously welds to form a thin welded portion that can divide between opposing end faces, and a cylindrical core portion that is composed of circular ring-shaped cord-like body portions that are sequentially integrally connected in a spiral winding by this welding. The other end along the inner surface of the hollow mandrel An apparatus for manufacturing a synthetic resin core, comprising: a rotation driving means that moves the material while rotating it spirally toward the side. 5. The welding device comprises a heating rotary wheel that rotates in contact with an inner peripheral surface of a joint portion of a cord-shaped body portion curved in a circular ring shape, and the inner peripheral surface of the joint portion is continuously spiraled. The manufacturing apparatus for a synthetic resin core according to claim 4, wherein a circular outer peripheral edge portion for welding is provided. 6. The rotary drive means is composed of a plurality of rotary filaments that rotate about the respective axes in the same direction at the same speed, and one end of each of these rotary filaments is connected to the inner circumference of the hollow mandrel. The grooves are provided in the surface at regular intervals in the circumferential direction and are respectively arranged in grooves that are spirally inclined from one end to the other end, and a part of the outer peripheral surface protruding from the groove is cylindrical. 5. The apparatus for producing a synthetic resin core according to claim 4, wherein the core portion is configured to be in sliding contact with the outer peripheral surface of the core portion to rotate the core portion.