JP2009043579A - Mounting method of external protection tube of electric wire, and forming device of this external protection tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an external protection tube (1) mountable on a terminal part of an electric wire (w) at an appropriate positioning state with no margin of error simply and with high efficiency. <P>SOLUTION: After a narrowed part (1a) is formed by pressing a heat disc (5) (41) onto one end of the external protection tube (1), the terminal part of the electric wire (w) is inserted and assembled, and the protection tube (1) is fastened, fixed, and integrated on the terminal part of an insulating covering of the electric wire (w) by heat contraction processing. A molding processing device of the protection tube (1) is equipped with: a reel suspension stand (12) to reel out a lengthy tube material (11); a specified length sending device (20) to send out the tube material intermittently; a cutting device (30); and a heat molding device (40), and after the narrowed part (11a) is heat-mold processed by pressing the heat disc (41) to the end of the tube material (11), it is cut by collaboration of the specified length sending device (20) and the cutting device (30). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is used as a component of a wire harness for automobiles or the like, and for unit wires and other insulation-coated wires, the exterior protection that double-coats and protects the terminal portion of the insulation coating adjacent to the core wire exposed portion of the terminal. The present invention relates to a tube mounting method for mounting a tube, and an exterior protective tube forming apparatus for forming the tube into a suitable form suitable for mounting.

As shown in the following Patent Document 1, an insulation coated electric wire used for a wire harness is further provided with a tape material or a tube material on the insulation coating portion excluding the terminal mounting portion of the terminal or the exposed portion of the core wire. May be covered.
JP 2004-179004 A

  In this case, as in the above-mentioned Patent Document 1, in addition to the case of covering the outer covering material over the entire length of the insulation coating, depending on the use of the electric wire, the core wire (3) at one end of the electric wire w as shown in FIG. A relatively short protective tube (1) having a length of about 5 to 20 mm is partially attached only to the terminal portion of the insulating coating (2) adjacent to the exposed portion (3a), and only the terminal portion is doubled. It may be required to be protected.

  Such a protective tube (1) for exterior use is generally made of a heat-shrinkable synthetic resin, and an electric wire is connected to the protective tube (1) previously cut to a predetermined length as shown in FIG. After loosely inserting the end portion of (w) and combining the two, the tube mounting end portion is heated from the outside by an appropriate heating means to cause thermal contraction of the tube (1), and thus the insulation coating It is attached by a technique of tightly covering and integrating with the outer surface of (2).

  However, in the case of the above attachment method, the position of the tube is unstable at the stage where the short cylindrical protective tube (1) is combined with the original loosely fitted state at the end of the electric wire (w). Therefore, as shown by a solid line in FIG. 2, it is too biased toward the exposed portion of the core wire (3a), or conversely, it enters too much in the direction of the insulation coating (2) as shown by a two-dot chain line in FIG. In many cases, it will be in the state. For this reason, when the heat shrinkage is fixed as it is, the length of the exposed portion (3a) of the core wire (3) becomes insufficient with respect to the design value, or conversely, the root portion of the core wire exposed portion (3a) It becomes an externally exposed product and becomes a defective product, causing a significant decrease in yield.

  In particular, in the case of electric wires for automobiles or household appliances, the occurrence of defective products such as those mentioned above may lead to serious accidents during use. The generation of defective products as described above has been fatal to production efficiency.

  In view of this, the present invention firstly allows the covering operation of the outer protection tube to the electric wire end portion to be performed more easily and efficiently without causing an error in the mounting position. An object of the present invention is to provide a method for mounting an exterior protection tube that can significantly improve the quality and yield of an electric wire equipped with a protection tube.

  A second object of the present invention is to provide a tube forming apparatus capable of automatically producing an exterior protection tube used in the above mounting method with high accuracy and high efficiency.

  For the above first object, the present invention provides the following means.

That is, in the mounting method of the exterior protection tube in which the exterior protection tube of a predetermined length is attached to the terminal portion of the insulation coating of the electric wire forming the core wire exposed portion,
A thermoforming step of forming a constricted portion due to thermal shrinkage at one end of the exterior protection tube by pressing one end of the heat-shrinkable exterior protection tube against a heating plate;
Next, an assembling step of inserting the end portion of the electric wire through the outer protective tube obtained by this thermoforming step and projecting the exposed portion of the core wire outward from the narrowed portion,
Next, a heat shrinking step of heating the terminal portion of the electric wire assembled with the exterior protection tube from the outside, heat shrinking the exterior protection tube, and tightly integrating the outer surface of the insulation coating;
It is the attachment method of the exterior protection tube of the electric wire characterized by including.

  In addition, for the second object, the present invention provides the following means.

That is, a reel suspension base for detachably suspending one or more reels wound with a long tube material of an exterior protection tube made of heat-shrinkable resin;
A fixed length delivery device arranged sequentially along the horizontal delivery direction of the long tube material from the reel suspended from the suspension base, a cutting device, and a thermoforming device,
While the fixed length delivery device is capable of intermittently feeding forward by clamping the long tube material,
The thermoforming device has a heating plate that is movable in the front-rear direction, and moves the hot plate to the distal end surface of the long tube material fed forward by the fixed length feeding device and presses it for a predetermined time, After forming a constricted portion due to thermal contraction at the distal end edge of the tube material, the heat plate can be retracted to the standby position,
The cutting device is configured to cut the distal end portion including the narrowed portion of the long tube material into a predetermined length after the thermoforming operation by the thermoforming device is finished. It is a shaping | molding processing apparatus of a protection tube.

  This molding apparatus is preferably recommended to be in the following form.

That is, the fixed length delivery device has first and second clamping devices arranged adjacent to each other in the front-rear direction,
After the long tube material is moved by the first clamping device to a position where the tip portion slightly protrudes from the fixed lower surface plate of the cutting device, the narrow plate portion is thermoformed by the hot platen of the thermoforming device. I,
Next, after the long tube material is further fed forward by a predetermined distance by the second clamping device, the cutting device is configured to be cut by the cutting device.

  In the mounting method of the outer sheath protection tube of the electric wire according to the present invention, the outer sheath protection tube cut to a predetermined length is pressed against the one end of the tube at the stage before being assembled to the electric wire, A constriction due to heat shrinkage is formed at one end of the exterior protection tube. This constricted part is formed by heat shrinkage, so that the peripheral wall of the tube is curved inwardly in an arc shape as it reaches the terminal, and a curved funnel shape having a small opening with a reduced diameter at the center part Formed as a thing. Therefore, when the terminal portion of the electric wire is inserted into this protective tube in the next step, that is, when the core wire exposed portion is inserted from the other end side (terminal side opposite to the narrowed portion) of the protective tube, The amount of insertion is regulated by the inner surface coming into contact with the end line of the wire insulation coating. For this reason, the core wire exposed portion passes through the small opening of the narrowed portion, and is in a state where a predetermined length region is projected to the outside. Then, the assembly part of the above-mentioned exterior protection tube is subsequently heated from the outside to cause heat shrinkage of the heat-shrinkable exterior protection tube, so that the exterior protection tube can be accurately placed at a predetermined position, that is, unwilling. It is possible to firmly and tightly integrate the terminal portion of the electric wire without causing a serious misalignment state.

  Therefore, the electric wire with an exterior protection tube manufactured by the method of the present invention can be a highly accurate one in which the length of the exposed portion of the core wire at one end is set to a specified value with almost no error. Moreover, it is possible to easily perform the assembly work of the external protection tube wire to the terminal, which is actually performed manually, without paying special attention to the assembly position, resulting in the production efficiency of the electric wire with the external protection tube. Can greatly improve.

  In addition, according to the molding apparatus for an exterior protection tube according to the present invention, the exterior protection tube in a state before assembly having a narrowed portion at one end used in the above-described tube mounting method is mechanically fully automated. Can be mass-produced.

  In addition, the device itself has a simple structure and can be less likely to fail or malfunction, and a plurality of protective tubes can be molded simultaneously from a plurality of long tube materials. Easily change the length of the protective tube corresponding to changes in the required protection area at the end of the wire, or change the size of the small opening in the constriction corresponding to the change in the thickness of the exposed portion of the core wire It can be used and has excellent versatility.

  In particular, when the fixed length delivery device is constituted by the first and second two clamping devices and they are operated alternately to carry the forward delivery action of the long tube material, The change in the length of the protective tube can be accommodated by a relatively simple sequence control.

  FIG. 1 shows an example of an electric wire (w) with an exterior protection tube (1) to be manufactured according to the present invention as described above. (2) is a wire covering of the electric wire (w), (3) is a core wire, (3a) is a core wire exposed portion at one end, and (4) is a terminal attached to the other end.

  In the manufacture of the electric wire (w) with the protective tube (1) as described above, in one embodiment of the tube mounting method according to the present invention, a heat-shrinkable synthetic resin first cut into a predetermined length as shown in FIG. An exterior protection tube (1) made of a material is prepared. Then, one end of the protective tube (1) is pressed vertically against a separately prepared hot plate (5) such as an iron as shown in FIG. 3 and held for a predetermined time. Then, the exterior protection tube (1) is deformed into a curved shape so that only the end region is thermally contracted by heat received from the one end surface, and the peripheral wall is wound inward, and the end surface is centered on the end surface. A narrow funnel-shaped narrowed portion (1a) having a small opening (1b) whose opening is deformed small is formed. In this document, this narrow portion forming process is referred to as a thermoforming process. Here, the temperature of the hot platen (5) is appropriately determined depending on the type of heat-shrinkable resin material of the tube, but generally it should not be set too high from the viewpoint of preventing danger in the work environment. It is preferable to set the temperature in the range of about 150 ° C to 250 ° C, preferably about 150 ° C to 200 ° C.

  Next, the said terminal part of the electric wire (w) which formed the core wire exposure part (3a) in the end is inserted in the exterior protection tube (1) as shown in FIG. 3 which finished said thermoforming process. As shown in FIG. 4, the insertion direction is such that the core wire exposed portion (3a) is inserted from the end surface opening (1c) opposite to the constricted portion (1a). When the insertion length reaches a predetermined distance by this insertion operation, the end line of the wire covering (2) of the electric wire (w) hits the inner surface of the funnel-shaped peripheral wall of the narrowed portion (1a) of the protective tube (1). , Further insertion is restricted. Therefore, at this stage, the exposed portion (3a) of the core wire is in a state in which a portion of a predetermined length (L) on the distal end side protrudes outside through the small opening (16). The above process is an assembling process in which the protective tube (1) is manually assembled at a predetermined position on the electric wire (w).

  Next, the electric wire (w) with a protective tube which finished the said assembly | attachment process is attached | subjected to a heat contraction process. In this heat shrinking step, at least the assembly portion of the protective tube (i) is heated from the outside to cause heat shrinkage of the tube (1), and the outer surface of the insulating coating of the electric wire (w) It is to be integrated closely. This heating method may be a method of heating with hot air using a hot air type heater such as a hair dryer, or holding in a heating furnace held at a predetermined high temperature for a predetermined time, or passing through a heating furnace. It is also good. The heating means is arbitrary.

  When adopting the tube mounting method as described above, in particular, it is easy to accurately position the mounting position of the protective tube (1) with respect to the terminal portion of the electric wire (w), and the electric wire is connected to the protective tube (1). It is possible to perform the assembling manual operation by inserting and assembling the terminal portion of (w) extremely efficiently, and the projection length of the core wire exposed portion (3a) from the protective tube (1) is required for design. There is an advantage that a high-quality electric wire accurately set in length can be manufactured with high efficiency.

  In the above embodiment, the exterior protection tube (1) cut in advance to a predetermined length is subjected to a thermoforming step for forming the narrowed portion (1a). As in the embodiment, after the thermoforming processing is performed on the distal end portion of the long tube material, this is cut into a predetermined length to obtain the protective tube (1) with the narrowed portion (1a). .

  FIGS. 6 to 9 show a tube for mechanically automatically producing an external protective tube (1) having a predetermined length having a heat shrinkage constriction (1a) at one end as described above from a long tube material. 1 shows a preferred embodiment of a forming apparatus.

  In FIG.1 and FIG.2 which shows the whole structure of the said shaping | molding processing apparatus, the long tube material made from the heat-shrinkable synthetic resin used as the material of an exterior protection tube (1) on the outer end of the base table (10) ( A suspension device (12) is provided that can rotatably support a plurality of reels (11a) wound around 11) side by side.

  On the base table (10), a pair of rails (13) (13) on the left and right sides are provided in parallel along the pulling direction of the long tube material (11), and in parallel with the pulling direction of the tube material. A pair of guide plates (14) and (15) are provided at a predetermined interval before and after. These guide plates (14) and (15) are provided with a plurality of insertion guide holes (14a) and (15a) for the tube material (11) in a horizontal row, and the tube material is inserted into these guide holes (14a and 15a). By inserting (11), the tube material can be guided in parallel and horizontally in the forward direction.

  On the base table (10), a fixed length delivery device (20), a cutting device (30), and a thermoforming device (40) are sequentially provided along the horizontal delivery direction of the tube material (11). Is provided.

  The fixed length delivery device (20) is located between both guide plates (14) (15) and has two front and rear first and second clamping devices (20A) (20B). These first and second clamping devices (20A) and (20B) have the same structure that is movable in the front-rear direction, and as shown in detail in FIG. 8, sliders mounted on rails (13) and (13). (21) It has a rod-like lower attachment member (22) straddling (21) and an inverted portal connection bridge (23), and is connected to the lower attachment member (22) below the connection bridge (23). A corresponding rod-like upper attachment member (24) is provided so as to be lifted and lowered in a form suspended from an air cylinder (25) for lifting operation. In FIG. 8, (26) is an elevating guide for the upper adhesive member (22), (22a) and (24a) are concave portions for positioning the tube material, and (27) is the front and rear of each clamping device (20A) (20B). An advancing / retreating air cylinder (28) that moves a predetermined distance in the direction is a passive plate to which the rod of the cylinder (27) is connected. These first and second clamping devices (20A) and (20B) are operated alternately in order, and the long tube material (11) can be intermittently sent forward at a predetermined distance.

  The cutting device (30) cuts a long tube material into a predetermined length of about 5 to 20 mm after thermoforming, and includes a fixed lower platen (31) and the lower platen (31). And a cutting blade (32) that is driven up and down. The lower surface plate (31) is provided adjacent to the front side of the front side guide plate (14). The cutting blade (32) is located directly above the front surface of the lower surface plate (31), and is mounted in a horizontal manner between a pair of left and right lifting blocks (33) (33). It is attached to the front surface of the lower projection. The elevating block (33) is freely slidable on a pair of guide rods (35) (35) suspended from the lower surface side of the upper frame portion of the portal frame (34) fixed on the base table (10). Installed on. Then, the blade attaching plate (32A) connecting them is driven by an elevating action air cylinder (36) on the upper frame portion so as to move up and down with a predetermined stroke, and the cutting blade (32) is ascending standby shown in FIG. It can be moved up and down between the position and the lower cutting position where the lower edge of the cutting edge reaches the upper surface of the lower surface plate (31).

  The thermoforming device (40) is provided at the forefront position in the feeding direction of the long tube material (11), and is in front of the lower surface plate (31) of the cutting device (30) and is a long tube. The material (11) has a horizontally long bar-like heating plate (41) arranged with its rear surface facing the front end of the row. The hot platen (41) is mounted on the hot platen mounting block (42), and the hot platen mounting block (42) is a pair of left and right sliders (43) mounted on rails (13) (13). (43) is attached horizontally. And by driving this hot platen mounting block (42) by the air cylinder (44) for advancing and retracting operation via the passive plate (45), the hot platen (41) is set to a standby position shown by a solid line in FIG. Moving back and forth between the forming action position where the rear surface of the heating plate (41) is lightly pressed against the front end surface of the long tube material (11) slightly protruding from the lower surface plate (31) indicated by the chain line in FIG. It is supposed to be able to make it.

  A dropping hole (51) with a funnel-shaped guide (52) for dropping and releasing the cut outer protective tube (1) is provided at a position below the cutting device (30) in the base table (10). The protective tube (1) falling from the hole (51) can be collected and collected by a collection box (53) provided therebelow.

  Next, the operation of the molding apparatus will be described.

  First, the long tube material (11) is pulled out from one or more reels (11a) set on the reel suspension base (12), and the guide holes (15a) (15a) ( 14a) is sequentially inserted, and the tip is preferably positioned on the lower fixed surface plate (31) of the cutting device (30) as shown in FIG.

  Next, the molding apparatus is activated.

  Then, first, the upper clamping member (24) of the first clamping device (20A) in the fixed length feeding device (20) is lowered by the drive of the air cylinder (25), and as shown in FIG. A portion near the tip of the tube material (11) is sandwiched between the upper and lower sandwiching members (22) and (24). Subsequently, while maintaining this squeezed state, the entire first clamping device (20A) is moved forward by a predetermined distance by the operation of the forward / backward movement air cylinder (27). As shown in FIG. 11 (c), this forward movement is slightly within the range where the tip of the long tube material (11) is about 2 to 5 mm from the front surface of the lower surface plate (31) of the cutting device (30). It stops when it is ejected.

  Then, the thermoforming device (40) is driven next. That is, the operation of the advancing / retreating air cylinder (44) causes the hot platen (41) to move forward and backward (toward the distal end of the long tube material). And as shown in (c) of FIG. 11, when the rear surface of the heat plate (41) lightly contacts the distal end surface of the long tube material (11), the advance operation of the heat plate (41) is stopped, It is maintained as it is for about 0.5 to 3 seconds, preferably about 1 to 2 seconds. As a result, the long tube material (11) made of heat-shrinkable resin is deformed due to heat contraction of the distal end portion that is closer to the hot platen (41) due to heat received from the distal end surface. Further, as shown in FIG. 10, a narrow portion (11a) having a substantially funnel cross section is formed in which the peripheral wall is rounded and curved inwardly at the tip of the tube material (11). In the center of the narrowed portion (11a), a small opening (11b) having a small diameter is left.

  After the thermoforming process, the hot platen (41) is moved back to the original standby position. At the same time, in the first clamping device (20A), as shown in FIG. 11 (d), the upper fastening member (24) is raised and returned to release the tube material (11).

  Instead, the second clamping device (20B) is activated. That is, the upper attachment member (24) is moved downward, and as shown in FIG. 11 (d), the long tube material (11) is placed between the lower attachment member and the lower attachment member (22) by 10 to several backwards from the tip. Attach at 10cm. Subsequently, the second clamping device (20B) is moved forward by a predetermined distance by the operation of the forward / backward movement cylinder (27). This moving distance is determined by the required length of the protective tube (1), and is usually variably set in the range of about 5 to 20 mm.

  And by this advancement movement, the long tube material (11) is moved forward while being pinched by the fastening members (22) and (24) of the second clamping device (20B), and the tip portion is cut. A predetermined length is projected forward from the cutting position on the lower surface plate (31) of the device (30).

  The cutting device (30) is then activated. That is, the cutting blade (32) is lowered by the operation of the lifting operation cylinder (36), and the tube material (11) is cut at a predetermined position on the lower surface plate (31). This cut tube piece is a product of the outer protection tube (1), as shown in FIG. 6, from the drop hole (12) provided in the base table (10) to the inside of the collection box (53). To be collected.

  The product of the exterior protection tube (1) is covered and mounted on the terminal portion of the electric wire (w) by the mounting method described above.

  According to the above protective tube forming apparatus, a short exterior protective tube (1) having a narrowed portion (1a) at one end can be mechanically fully automated and highly efficient without requiring detailed manual work. it can. In addition, a uniform product tube with high molding accuracy can be obtained.

  This type of exterior protection tube (1) used for protecting the end portion of the insulation coating in the unit wire of the wire harness is a very short length of about 5 to 20 mm in its entire length. For this reason, when such a short protective tube (1) is cut in advance and then the narrowed portion (1a) is to be thermoformed at one end, it may be mechanically performed. In addition, it is extremely troublesome in any case even when it is performed manually, but according to the molding processing apparatus of the present invention, as described above, starting from a long tube material, In addition, it is extremely advantageous in that a protective tube with good molding accuracy can be manufactured with high efficiency.

  The protective tube forming apparatus illustrated and described above is merely shown as a preferred embodiment of the present invention. In the present invention, any design change is allowed without departing from the configuration described in the claims.

It is a perspective view of the insulation covering electric wire which attached the exterior protection tube to the terminal part by the attachment method of the present invention. It is sectional drawing which shows the state before the thermoforming process which cut | disconnected the exterior protection tube from the long tube material. It is sectional drawing which shows the state which gave the thermoforming process to the said protection tube and formed the constriction part. It is a perspective view which shows the state in the middle of insertion which attaches an exterior protection tube to an electric wire. It is sectional drawing of the electric wire terminal part which shows the protection tube mounting state after heat shrink processing. 1 is a schematic longitudinal sectional side view showing an overall configuration of a preferred embodiment of a protective tube forming apparatus according to the present invention. It is a top view of embodiment same as the above. It is a front view of a fixed length delivery clamp apparatus. It is a partial top view of a cutting device and a thermoforming apparatus. It is sectional drawing which shows the thermoforming process state by pressing of the hot disc with respect to long tube material. It is a schematic side view showing the thermoforming process step by step, (A) is the initial setting completion state, (B) is the clamping state by the first clamping device, (C) is the state at the time of thermoforming, ) Shows the tube delivery state by the second clamping device, and (e) shows the state during the cutting process.

Explanation of symbols

w ... Electric wire 1 ... Exterior protection tube 1a ... Narrow part 1b ... Small opening 2 ... Insulation coating 3 ... Core wire 3a ... Core wire exposed part 5 ... Hot plate
11.Long tube material
11a ・ Reel
12.Reel suspension stand
13.Rail
20 ・ ・ Tube material feeding device
20A ・ ・ First clamp device
20B ・ ・ Second clamping device
21. ・ Slider
22. ・ Lower adhesive member
24 .. Upper adhesive member
25 ・ ・ Cylinder for lifting operation
27 ・ ・ Cylinder for forward / backward movement
30 ・ ・ Cutting device
31 ・ ・ Lower surface plate
32 ・ ・ Cutting blade
36 ・ ・ Cylinder for lifting operation
40 ・ ・ Thermoforming equipment
41 .. Hot plate
44 ・ ・ Cylinder for forward / backward movement
51 ... Drop hole
53 .. Collection box

Claims (3)

In the mounting method of the exterior protection tube for attaching the exterior protection tube of a predetermined length to the terminal portion of the insulation coating of the electric wire forming the core wire exposed portion,
A thermoforming step of forming a constricted portion due to thermal shrinkage at one end of the exterior protection tube by pressing one end of the heat-shrinkable exterior protection tube against a heating plate;
Next, an assembling step of inserting the end portion of the electric wire through the outer protective tube obtained by this thermoforming step and projecting the exposed portion of the core wire outward from the narrowed portion,
Next, a heat shrinking step of heating the terminal portion of the electric wire assembled with the exterior protection tube from the outside, heat shrinking the exterior protection tube, and tightly integrating the outer surface of the insulation coating;
The mounting method of the exterior protection tube of the electric wire characterized by including. A reel suspension base that detachably suspends one or more reels wound with a long tube material of an outer protective tube made of heat-shrinkable resin;
A fixed length delivery device arranged sequentially along the horizontal delivery direction of the long tube material from the reel suspended from the suspension base, a cutting device, and a thermoforming device,
While the fixed length delivery device is capable of intermittently feeding forward by clamping the long tube material,
The thermoforming device has a heating plate that is movable in the front-rear direction, and moves the hot plate to the distal end surface of the long tube material fed forward by the fixed length feeding device and presses it for a predetermined time, After forming a constricted portion due to thermal contraction at the distal end edge of the tube material, the heat plate can be retracted to the standby position,
The cutting device is configured to cut the distal end portion including the narrowed portion of the long tube material into a predetermined length after the thermoforming operation by the thermoforming device is finished. Protection tube forming equipment. The fixed length delivery device has first and second clamping devices arranged adjacent to each other in the front-rear direction,
After the long tube material is moved by the first clamping device to a position where the tip portion slightly protrudes from the fixed lower surface plate of the cutting device, the narrow plate portion is thermoformed by the hot platen of the thermoforming device. I,
Next, after the long tube material is further fed forward by a predetermined distance by the second clamp device, the cutting by the cutting device is performed. apparatus.

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